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SCHEDULE 14A

Joint Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Filed by the Registrant  x                            Filed by a Party other than the Registrant  ¨

Check the appropriate box:

Columbia Funds Series Trust

(Name of Registrant as Specified in its Charter)

Payment of Filing Fee (Check the appropriate box):

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Columbia Funds Series Trust

One Financial Center, Boston, Massachusetts 02111

(each, a “Fund” and collectively, the “Funds”)

IMPORTANT INFORMATION TO HELP YOU UNDERSTAND AND VOTE ON THE PROPOSALS

This is a brief overview of the matters on which you are being asked to vote. The accompanying Joint Proxy Statement contains more detailed information about each proposal, and we encourage you to read it in its entirety before voting. Your vote is important.

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Following the Transaction, the boards of directors/trustees of the RiverSource Fund Complex (collectively, the “Columbia RiverSource Boards”) and of the Columbia Fund Complex had ongoing discussions regarding a potential consolidated board of directors/trustees to oversee all or a portion of the Combined Fund Complex. In September 2010, these discussions culminated in an agreement between the Columbia RiverSource Boards and the Columbia Nations Board to have a consolidated board of directors/trustees for a portion of the Combined Fund Complex. Specifically, they agreed that the RiverSource Fund Complex and the portion of the Columbia Fund Complex overseen by the Columbia Nations Board should be overseen by a combined board of directors/trustees. In this regard, the Columbia Nations Board and the Columbia RiverSource Boards each determined that the consolidation would enhance the oversight of a larger fund family and achieve cost efficiencies for fund shareholders.

In order to effect the consolidation, the Governance Committee of the Columbia Nations Board, and the full Columbia Nations Board, have nominated the 16 individuals listed in the Joint Proxy Statement for election to the Columbia Nations Board, each to hold office for an indefinite term. Information about each nominee is set forth in the Joint Proxy Statement under Proposal 1.

The proposed amendment is part of a group of related proposals that, if approved, would align the investment management service and fee structures currently in place across most funds in the Combined Fund Complex. The proposed amendment to the IMS Agreement would affect the IMS Fee Funds and the LifeGoal Portfolios in different ways:

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The investment advisory fee rates payable by the IMS Fee Funds at all or most asset levels and by the LifeGoal Portfolios with respect to certain types of assets would increase, as described below. However, the net cumulative effect of the larger group of proposals is expected to be a reduction in the overall fees payable by the Combined Fund Complex. This will benefit many shareholders, especially since many shareholders own shares of more than one fund.

Moreover, the fees actually paid by the IMS Fee Funds and the LifeGoal Portfolios will be net of contractual expense limitations that will generally cap annual operating expense ratios at levels that are at or below the median net operating expense ratios of the other funds in the Fund’s respective peer group. These commitments may mitigate the impact of any fee rate increases resulting from the amended fee schedules.

A comparison of the investment advisory fee rates and gross and net expense ratios is included in the accompanying Joint Proxy Statement. If you do not hold shares of an IMS Fee Fund or LifeGoal Portfolio, your Fund’s investment advisory fee rates payable by your Fund under the IMS Agreement will not increase.

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The proposed amendment, which, for the Bundled Portfolios, also contemplates the termination of the related assumption agreement, would have the effect of: (i) unbundling the fee arrangements for the Bundled Portfolios (i.e., going forward, the Bundled Portfolios would pay fees for administration, custody, transfer agency, legal, audit, SEC registration fees, etc.) and (ii) changing the investment advisory fee structure so that each LifeGoal Portfolio would pay different investment advisory fee rates depending on the type of assets (i.e., no fee on assets invested in underlying proprietary funds that pay a management fee to Columbia Management, a stated rate on assets invested in third-party funds and a higher stated rate on assets invested directly in securities).

As further described in the accompanying Joint Proxy Statement, the proposed amendment also contemplates the unbundling of the Bundled Portfolio’ fee arrangements, which will provide greater clarity as to actual expenses incurred by the Bundled Portfolios and will standardize the fee structures across the LifeGoal Portfolios. Moreover, the cumulative net impact of the proposed amendment and related initiatives is expected to be a reduction in certain of LifeGoal Portfolio’s net operating expense ratios.

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NOTICE OF A JOINT SPECIAL MEETING OF SHAREHOLDERS

to be held on February [15], 2011

A Joint Special Meeting of Shareholders (the “Meeting”) of each Fund listed above and the Columbia Funds Series Trust (the “Trust”) as a whole will be held at [One Financial Center, Boston, Massachusetts, 02111] at [—] [a.m.][p.m.], local time on February [15], 2011. At the Meeting, shareholders will be asked to:

Please take some time to read the enclosed Joint Proxy Statement. It discusses these proposals in more detail. If you were a shareholder of a Fund on December [17], 2010, you may vote at the Meeting or at any adjournment of the Meeting on the proposal(s) applicable to your Fund(s). You are welcome to attend the Meeting in person. If you cannot attend in person to cast your vote, please vote by mail, telephone or internet. Just follow the instructions on the enclosed proxy card. If you have questions, please call the Funds’ proxy solicitor toll free at (800) 708-7953. It is important that you vote. The Board of Trustees of the Trust unanimously recommends that you vote FOR each nominee and FOR the proposed amendment to the Investment Management Services Agreement.

By order of the Board of Trustees,

Scott R. Plummer, Secretary

[—], 2010

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Columbia Funds Series Trust

One Financial Center, Boston, Massachusetts 02111

(each, a “Fund” and collectively, the “Funds”)

JOINT PROXY STATEMENT

Joint Special Meeting of Shareholders to be held on February [15], 2011

This Joint Proxy Statement is furnished to you in connection with the solicitation of proxies by the board of trustees (the “Columbia Nations Board”) of Columbia Funds Series Trust (the “Trust”) relating to a Joint Special Meeting of Shareholders (the “Meeting”) of the Funds and the Trust as a whole to be held at [One Financial Center, Boston, Massachusetts, 02111] on
February [15], 2011 at [—][a.m.][p.m.], local time. It is expected that this Joint Proxy Statement will be mailed to shareholders on or about January [4], 2011.

The purpose of the Meeting is to ask shareholders to:

Columbia International Value Fund (the “Feeder Fund”) is a feeder fund in a master/feeder structure, which means that it invests all or substantially all of its net investable assets in Columbia International Value Master Portfolio (the “Master Portfolio”), a series of Columbia Funds Master Investment Trust, LLC (the “Master Trust”). When actions related to the Master Portfolio are proposed to

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its interestholders, Feeder Fund shareholder approval of those actions is sought (hereinafter, as the context requires, the terms “Fund” or “Funds” include the Master Portfolio, the term “Trust” includes the Master Trust, and the term “Columbia Nations Board” includes the Board of Trustees of the Master Trust). The interestholders of the Master Trust are being asked to elect the nominees listed in Proposal 1 to the Board of Trustees of the Master Trust. For additional information about the voting mechanics with respect to the Feeder Fund, see “Other Information – Special Note for Shareholders of the Feeder Fund.”

Additional information about the Funds is available in their respective prospectuses, statements of additional information and semi-annual and annual reports to shareholders. The Funds’ most recent semi-annual and annual reports previously have been mailed to shareholders. Additional copies of any of these documents are available without charge upon request by writing Columbia Management Investment Services, Corp., P.O. Box 8081, Boston, MA 02266-8081, by calling (800) 345-6611 or by visiting www.columbiamanagement.com. All of these documents also are filed with the Securities and Exchange Commission (the “SEC”) and available on the SEC’s website at www.sec.gov.

This Joint Proxy Statement is available at http://www.columbiamanagement.com.

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GENERAL OVERVIEW

Proposal 1: Election of Trustees

The shareholders of the Funds of the Trust are being asked to elect the 16 individuals identified in Proposal 1 (the “Nominees”) to serve as trustees on the Columbia Nations Board. The Governance Committee of the Columbia Nations Board, and the full Columbia Nations Board, have nominated the Nominees for election to the Columbia Nations Board, each to hold office for an indefinite term. Information about each Nominee is set forth below under Proposal 1.

Proposal 2: Amendment to Investment Management Services Agreement

The shareholders of certain Funds are being asked to approve a proposed amendment to the Investment Management Services Agreement between the Trust, on behalf of the Funds, and Columbia Management Investment Advisers, LLC (“Columbia Management”) that is part of a group of related proposals, which, if approved, would align such Funds’ investment management service and fee structures with those currently in place across most funds in the family of investment companies. Information about the proposed amendment to the Investment Management Services Agreement is set forth under Proposal 2.

Effectiveness of the Proposals

Neither proposal is contingent on the outcome of the other proposal. In addition, approval of Proposal 2 by one IMS Fee Fund or LifeGoal Portfolio is not contingent on the approval of Proposal 2 by any other IMS Fee Fund or LifeGoal Portfolio.

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PROPOSAL 1 – ELECTION OF TRUSTEES

(All Funds)

On May 1, 2010, Ameriprise Financial, Inc. (“Ameriprise”), the parent company of Columbia Management, the Funds’ investment manager, acquired the long-term asset management business of Columbia Management Group, LLC and certain of its affiliated companies from Bank of America, N.A. (the “Transaction”). In connection with the Transaction, Columbia Management became the investment manager of the Columbia-branded funds (the “Columbia Fund Complex”), in addition to the funds then branded as RiverSource, Seligman and Threadneedle funds (the “RiverSource Fund Complex,” and together with the Columbia Fund Complex, the “Combined Fund Complex”).

Following the Transaction, the boards of directors/trustees of the RiverSource Fund Complex (collectively, the “Columbia RiverSource Boards”) and the boards of trustees of the Columbia Fund Complex had ongoing discussions regarding a potential consolidated board of directors/trustees to oversee all or a portion of the Combined Fund Complex. In September 2010, these discussions culminated in an agreement between the Columbia RiverSource Boards and the Columbia Nations Board to have a consolidated board of directors/trustees for a portion of the Combined Fund Complex. Specifically, they agreed that the RiverSource Fund Complex and the portion of the Columbia Fund Complex overseen by the Columbia Nations Board should be overseen by a combined board of directors/trustees. In this regard, the Columbia Nations Board and Columbia RiverSource Boards each determined that the consolidation would enhance the oversight of a larger fund family and should achieve cost efficiencies over time for certain fund shareholders.

Each Fund is a series of the Trust. In order to effect the consolidation, at a meeting held on September 20, 2010, the Governance Committee of the Columbia Nations Board nominated the Non-Interested Nominees (defined below) to the Columbia Nations Board. In addition, at a meeting held on September 20, 2010, the Columbia Nations Board, including a majority of the trustees who are not “interested persons,” as defined in the Investment Company Act of 1940, as amended (the “1940 Act”), of the Trust (each, a “Non-Interested Trustee” and collectively, the “Non-Interested Trustees”), unanimously accepted and endorsed these nominations, nominated the Interested Nominees (defined below) and voted to present each Nominee to shareholders for election as trustees. The Columbia Nations Board currently has no reason to believe that any Nominee will become unavailable for election as a trustee, but if such unavailability should occur before the Meeting, the proxies will be voted for such other individuals as the Governance Committee of the Columbia Nations Board and the full Columbia Nations Board may designate.

A Nominee is deemed to be “non-interested” to the extent the Nominee is not an “interested person,” as that term is defined in Section 2(a)(19) of the 1940 Act, of the Trust (each, a “Non-Interested Nominee” and collectively, the “Non-Interested Nominees”). The Non-Interested Nominees are: Kathleen Blatz, Edward J. Boudreau, Jr., Pamela G. Carlton, William P. Carmichael, Patricia M. Flynn, William A. Hawkins, R. Glenn Hilliard, Stephen R. Lewis, Jr., John F. Maher, John J. Nagorniak, Catherine James Paglia, Leroy C. Richie, Alison Taunton-Rigby and Minor M. Shaw.

Anthony M. Santomero and William F. Truscott (each, an “Interested Nominee” and collectively, the “Interested Nominees”) are or would be treated as “interested persons” of the Trust. Although Mr. Santomero is “independent” of Columbia Management and its affiliates, in that he is not a director, officer or employee thereof, Mr. Santomero is an “interested person” of the Trust (an “Interested Trustee”) because he serves as a director of Citigroup, Inc. and Citigroup, N.A., which may engage from time to time in brokerage execution, principal transactions and/or lending relationships with the Funds or other funds or accounts advised/managed by Columbia Management and/or a Fund’s subadviser. William F. Truscott, if elected, would be an “interested person” of the Trust because he serves as Chairman of the Board of Columbia Management (and was previously the President, Chairman of the Board and Chief Investment Officer of Columbia Management from 2001-2010) and as a senior executive of Ameriprise, the parent company of Columbia Management, in which he is also a stockholder.

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If the Nominees are elected by shareholders, at least 75% of the Columbia Nations Board’s trustees will continue to be Non-Interested Trustees. The Nominees would serve as trustees in accordance with the organizational documents of the Trust. Each trustee would serve for an indefinite term. A trustee’s term may terminate by the election of his or her successor, by the termination or dissolution of the Trust, or by his or her death, resignation, removal, retirement or incapacity. Under the current Columbia Nations Board’s policy a trustee may serve until the next Columbia Nations Board meeting after he or she reaches the mandatory retirement age established by the Columbia Nations Board, or the fifteenth anniversary of the first Columbia Nations Board or Columbia RiverSource Board meeting he or she attended as a trustee.

Information Regarding the Non-Interested Nominees

Background information regarding each of the Non-Interested Nominees follows.

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Information Regarding the Interested Nominees

Background information regarding each of the Interested Nominees follows.

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Nominees’ Beneficial Ownership of Shares of Each Fund

Appendix A to this Joint Proxy Statement provides information, as of September 30, 2010 (unless otherwise indicated), about the beneficial ownership by the Nominees of shares of each Fund.

Status of Current Trustees

Messrs. Boudreau, Carmichael, Hawkins, Hilliard, Nagorniak and Santomero and Ms. Shaw were most recently elected to the Columbia Nations Board by shareholders in 2010. Together, such trustees currently comprise the entire Columbia Nations Board. The Columbia Nations Board met on [•] occasions during the fiscal year ended [—]. Information about directors/trustees of the Columbia RiverSource Boards who are also Nominees is set forth under “Information Regarding the Non-Interested Nominees” and “Information Regarding the Interested Nominees” above.

Leadership Structure and Risk Oversight

The Columbia Nations Board oversees management of the Trust and the Funds. The Columbia Nations Board has a duty to act in the best interest of shareholders when supervising and overseeing the management and operations of the Trust. The Columbia Nations Board currently consists of seven trustees who have extensive and varied experience and skills. Six of the seven trustees are Non-Interested Trustees. Further information about the background and qualifications of each of the Trustees can be found in the sections titled “Information Regarding the Non-Interested Nominees” and “Information Regarding the Interested Nominees” above.

The Columbia Nations Board has appointed William P. Carmichael, a Non-Interested Trustee, to serve in the role of Chairman. The Chairman actively participates in the development of the agendas for Columbia Nations Board meetings, presides at Columbia Nations Board meetings and acts as a liaison with service providers, officers, attorneys, and other trustees generally between meetings. The Chairman may also perform such other functions as may be delegated by the Columbia Nations Board from time to time. Except for any duties specified herein or pursuant to the Trust’s governing documents, the designation of Chairman does not impose on such Non-Interested Trustee any duties, obligations or liability that are greater than the duties, obligations or liability imposed on such person as a member of the Columbia Nations Board generally. The Nominees have agreed, if all of the Nominees are elected by the shareholders of the Trust, to appoint Stephen R. Lewis, Jr. as Chairman subsequent to the Meeting.

The Columbia Nations Board has several standing committees (the “Committees”) which are an integral part of the Funds’ overall governance and risk management oversight structure. The standing Committees are the Audit Committee, the Governance Committee, the Contracts Review Committee and the Investment Committee. The roles of each Committee are more fully described in the section titled “Current Committees of the Columbia Nations Board” below.

The Funds have retained Columbia Management as the Funds’ investment manager and administrator. Columbia Management provides the Funds with investment advisory services, and is responsible for day-to-day management and administration of the Funds and management of the risks that arise from the Funds’ investments and operations. The Columbia Nations Board is responsible for overseeing Columbia Management and other service providers in the operation of the Trust, including with respect to risk management functions. The Funds and the Trust are subject to a number of risks, including investment, compliance, operational, and valuation risks, among others. Day-to-day risk management functions are subsumed within the responsibilities of Columbia Management, the Funds’ subadvisers and other service providers (depending on the nature of the risk), who carry out the Funds’ investment management and business affairs. Each of Columbia Management, the Funds’ subadvisers and other

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service providers has their own independent interest in risk management, and their policies and methods of carrying out risk management functions will depend, in part, on their analysis of the risks, functions and business models.

Risk oversight forms part of the Columbia Nations Board’s general oversight of the Funds and the Trust and is addressed as part of various activities of the Columbia Nations Board and Committees. The Columbia Nations Board recognizes that it is not possible to identify all of the risks that may affect the Funds or to develop processes and controls to eliminate or even mitigate their occurrence or effects. As part of its regular oversight of the Trust, the Columbia Nations Board, directly and through one or more Committees, interacts with and reviews reports from, among others, Columbia Management, the Funds’ subadvisers, the independent registered public accounting firm for the Funds, and internal auditors for Columbia Management or its affiliates, as appropriate, regarding risks faced by the Funds and relevant risk functions. The Columbia Nations Board and the Audit Committee of a Fund also meet periodically with the Funds’ Chief Compliance Officer to receive reports regarding the compliance of the Funds and their principal service providers with the U.S. federal securities laws and their internal compliance policies and procedures. The Columbia Nations Board and its Audit Committee have oversight responsibilities with respect to the compliance program of the Funds and certain of its service providers, and also receive periodic and annual reports from the Funds’ Chief Compliance Officer, as required under applicable regulations. The Columbia Nations Board, with the assistance of the Investment Committee, reviews investment policies and risks in connection with its review of the Funds’ performance, and meets periodically with the portfolio managers of the Funds to receive reports regarding the management of the Funds, including each Fund’s investment risks. In addition, as part of the Columbia Nations Board’s periodic review of the Funds’ advisory, subadvisory and other service provider agreements, the Columbia Nations Board may consider risk management aspects of their operations and the functions for which they are responsible.

The Non-Interested Trustees have engaged independent legal counsel to assist them in performing their oversight responsibilities. The Columbia Nations Board reviews its leadership structure periodically and believes that its structure is appropriate because it allows the Columbia Nations Board to exercise informed and independent judgment over matters under its purview, and it allocates areas of responsibility among Committees of trustees and the full Columbia Nations Board in a manner that enhances effective oversight. In particular, the Columbia Nations Board believes that having a Non-Interested Trustee serve as the chair of the Columbia Nations Board and of each Committee promotes independence from Columbia Management in developing agendas and conducting meetings. The Columbia Nations Board believes that its Committee structure makes the oversight process more efficient and more effective by allowing smaller groups of trustees to bring increased focus to matters within the purview of each Committee. The leadership structure of the Columbia Nations Board, including the Committee structure and the manner in which the Columbia Nations Board conducts its risk oversight role, may be changed, at any time and in the discretion of the Columbia Nations Board, including in response to changes in circumstances or the characteristics of the Trust. In this regard, it may be changed in certain respects as the Columbia RiverSource Boards consolidate with the Columbia Nations Board and consider enhancing and reconciling various practices that have historically been different.

Current Committees of the Columbia Nations Board

The Trust has four standing Committees, which are the Audit Committee, the Contracts Review Committee, the Governance Committee and the Investment Committee.

In general, the function of the Audit Committee is oversight of the financial aspects of the Trust and the Funds and approval of and interaction with the Funds’ independent registered public accounting firm. Management (which generally means the appropriate officers of the Trust, and the Funds’ investment manager, administrator(s) and other key service providers (other than the independent registered public accounting firm)) is primarily responsible for the preparation of the financial statements of the Funds, and the independent registered public accounting firm is responsible for auditing those financial statements. Management also is responsible for maintaining appropriate systems for accounting and “internal controls over financial reporting” (as such term is defined in Rule 30a-3 under the 1940 Act), and the independent

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registered public accounting firm is primarily responsible for considering such internal controls over financial reporting in connection with its financial statement audits. While the Audit Committee has the duties and powers set forth in the Audit Committee charter, the Audit Committee is not responsible for planning or conducting any Fund audit or for determining whether the Funds’ financial statements are complete and accurate and are in accordance with generally accepted accounting principles.

The Audit Committee has, among other things, specific power and responsibility to: (i) oversee the Funds’ accounting and financial reporting processes and practices, their internal controls over financial reporting and, as appropriate, the internal controls over financial reporting of the Funds maintained by key service providers; (ii) approve, and recommend to the full Columbia Nations Board for its approval in accordance with applicable law, the selection and appointment of an independent registered public accounting firm for the Funds prior to the engagement of such independent registered public accounting firm; (iii) pre-approve all audit and non-audit services provided to the Funds by its independent registered public accounting firm, directly or by establishing pre-approval policies and procedures pursuant to which such services may be rendered, provided however, that the policies and procedures are detailed as to the particular service and the Audit Committee is informed of each service, and such policies do not include the delegation to management of the Audit Committee’s responsibilities under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or applicable rules or listing requirements; and (iv) pre-approve all non-audit services provided by the Funds’ independent registered public accounting firm to the Funds’ investment manager and any entity controlling, controlled by, or under common control with the investment manager that provides ongoing services to the Funds, if the engagement relates directly to the operations and financial reporting of the Funds. The members of the Audit Committee are William A. Hawkins (Chair), Edward J. Boudreau, Jr. and William P. Carmichael. The Audit Committee members are all Non-Interested Trustees. The Audit Committee met on five occasions during the fiscal years ended February 28, 2010 and March 31, 2010.

The primary responsibilities of the Contracts Review Committee, as set forth in its charter, include reviewing and making recommendations to the Columbia Nations Board as to: (i) contractual arrangements; (ii) the factors considered in approving investment advisory and the investment subadvisory agreements; and (iii) service provider oversight and performance. Among other responsibilities, the Contracts Review Committee also oversees and coordinates activities of consultants and legal or financial experts that may be engaged under certain circumstances. The members of the Contracts Review Committee are R. Glenn Hilliard (Chair), William P. Carmichael, John J. Nagorniak and Anthony M. Santomero. With the exception of Mr. Santomero, an Interested Trustee who is not a director, officer or employee of Columbia Management or any of its affiliates, the Contracts Review Committee members are all Non-Interested Trustees. The Contracts Review Committee met on four occasions during the fiscal years ended February 28, 2010 and March 31, 2010.

The primary responsibilities of the Governance Committee include, as set forth in its charter: (i) nominating Non-Interested Trustees; (ii) overseeing issues of corporate governance for the Trust and the Funds; (iii) addressing matters relating to compensation of Trustees who are not current directors, officers or employees of the Funds’ investment manager or subadviser or any control affiliate thereof, including deferred compensation and retirement policies; and (iv) evaluating each Fund’s board of trustees and the Columbia Nations Board and its committee structure as often as the Governance Committee deems necessary or desirable to determine whether each is functioning effectively. The Governance Committee shall determine the nature of the evaluation and its role therein in its sole discretion. The members of the Governance Committee are Minor M. Shaw (Chair), William A. Hawkins, R. Glenn Hilliard and William P. Carmichael (ex officio). The Governance Committee members are all Non-Interested Trustees. The Governance Committee met on seven occasions during the fiscal years ended February 28, 2010 and March 31, 2010.

The primary responsibilities of the Investment Committee are, as set forth in its charter, to assist the Columbia Nations Board in carrying out its oversight responsibilities in specific areas of investment management, both by acting as liaison between the full Columbia Nations Board and Columbia Management on investment matters, and by acting on behalf of the Columbia Nations Board with respect to investment issues in extraordinary circumstances when it is impractical to convene a meeting of the full

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Columbia Nations Board. In carrying out these general responsibilities, the Investment Committee assists the Columbia Nations Board in connection with issues relating to: the investment policies and procedures adopted for the Funds; appropriate performance benchmarks and other comparative issues; portfolio management staffing and other personnel issues of Columbia Management; investment-related compliance issues; possible exemptive applications or other relief necessary or appropriate with respect to investment matters; and other investment related matters referred from time to time to the Investment Committee by the full Columbia Nations Board. The Investment Committee reports its activities to the full Columbia Nations Board on a regular basis and is responsible for making such recommendations with respect to the matters described above and other matters as the Investment Committee may deem necessary or appropriate. The Chairperson of the Investment Committee is Edward J. Boudreau, Jr. Each trustee is a member of the Investment Committee. With the exception of Mr. Santomero, an Interested Trustee who is not a director, officer or employee of Columbia Management or any of its affiliates the Investment Committee members are all Non-Interested Trustees. The Investment Committee met on seven occasions during the fiscal years ended February 28, 2010 and March 31, 2010.

The Trust’s Declaration of Trust does not set forth any specific qualifications to serve as a trustee other than that each trustee shall be an individual of at least 21 years of age who is not under a legal disability. The charter of the Governance Committee also does not set forth any specific qualifications, but does set forth certain factors that the Governance Committee may take into account in considering trustee candidates. The charter of the Governance Committee is provided in Appendix B. The Governance Committee’s policy with respect to considering trustee candidates recommended by shareholders, and the procedures to be followed by shareholders in submitting such recommendations, are set forth in Section 3 of such charter. The Governance Committee has not established any specific minimum qualifications that must be met by a nominee or specific qualities or skills that the Governance Committee believes are necessary for one or more of the trustees to possess.

The Governance Committee does not have a formal process for identifying and evaluating nominees, including nominees recommended by shareholders. Instead, it follows the process it deems appropriate under the circumstances. Among the attributes or skills common to all trustees are their ability to review critically, evaluate, question and discuss information provided to them, to interact effectively with the other trustees, Columbia Management, the Funds’ subadvisers, other service providers, counsel and the independent registered public accounting firm, and to exercise effective and independent business judgment in the performance of their duties as trustees. Each trustee’s ability to perform his or her duties effectively has been attained through: (i) the individual’s business and professional experience and accomplishments; (ii) the individual’s experience working with the other trustees and management; (iii) the individual’s prior experience, if any, serving on the boards of public companies (including, where relevant, other investment companies) and other complex enterprises and organizations; and (iv) his or her educational background, professional training, and/or other life experiences. Generally, no one factor was decisive in determining that an individual should serve as a trustee.

Nominee Qualifications

The following is a summary of the particular professional and other experience of each Nominee that qualifies each person to serve as a trustee of the Trust as of the date of this Joint Proxy Statement:

Kathleen Blatz. Ms. Blatz has been a director/trustee on the Columbia RiverSource Boards since 2006. Ms. Blatz has ten years of judicial experience and substantial other legal and government experience. Ms. Blatz served as an associate justice of the Minnesota Supreme Court from 1996 to 1998 and as Chief Justice of the court from 1998 to 2006. Ms. Blatz served in the Minnesota House of Representatives from 1979 to 1994.

Edward J. Boudreau, Jr. Mr. Boudreau has been a trustee of certain trusts in the Columbia Fund Complex since 2005. In addition, he has over thirty years of business and consulting experience, primarily in the financial services industry, including as the chief executive of a mutual fund management company.

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Pamela G. Carlton. Ms. Carlton has been a director/trustee on the Columbia RiverSource Boards since 2007. Ms. Carlton has significant experience in consulting and in investments, having served as a Managing Director in U.S. Equity Research at J.P. Morgan Chase.

William P. Carmichael. Mr. Carmichael has been a trustee of certain trusts in the Columbia Fund Complex since 1999, and has served as Chairman of the Columbia Nations Board and of the boards of the other trusts in the Columbia Fund Complex since 2003. Mr. Carmichael served in various senior financial and directorship positions with global consumer products companies. Mr. Carmichael is a certified public accountant and a licensed attorney.

Patricia M. Flynn. Ms. Flynn has been a director/trustee on the Columbia RiverSource Boards since 2004. Ms. Flynn currently serves as Trustee Professor of Economics and Management of Bentley University, and was the former dean of a graduate school of business.

William A. Hawkins. Mr. Hawkins has been a trustee of certain trusts in the Columbia Fund Complex since 2005. He currently serves as the President and Chief Executive Officer of California General Bank and has over thirty years of executive level experience in the banking industry. Mr. Hawkins is a certified financial planner and a chartered property and casualty underwriter, as well as holding series 7, 24 and 63 licenses from the Financial Industry Regulatory Authority.

R. Glenn Hilliard. Mr. Hilliard has been a trustee of certain trusts in the Columbia Fund Complex since 2005. Mr. Hilliard is currently the Chairman and Chief Executive Officer of The Hilliard Group, LLC. Mr. Hilliard has over five years executive level experience in the insurance industry. Mr. Hilliard has served on the board of directors and as non-executive chairman of Conseco, Inc. for a number of years. Mr. Hilliard is also a licensed attorney.

Stephen R. Lewis, Jr. Mr. Lewis has been the Chairman of the Columbia RiverSource Boards since 2007 and a director/trustee on the Columbia RiverSource Boards since 2002. From 1987 to 2002, Mr. Lewis served as President of Carleton College, after which he continued to serve as President Emeritus and Professor Emeritus of Economics. Mr. Lewis has more than thirty years experience in Asia and Africa, primarily advising governments on economic policy and negotiations of foreign investment and financing agreements. Mr. Lewis is also a director of Valmont Industries, Inc.

John F. Maher. Mr. Maher has been a director/trustee on the Columbia RiverSource Boards since 2008. Mr. Maher has extensive experience in the financial services industry, and was formerly President, Chief Executive Officer and a director of Great Western Financial Corporation.

John J. Nagorniak. Mr. Nagorniak has been a trustee of certain trusts in the Columbia Fund Complex since 2008. Mr. Nagorniak has served in executive level and director positions for over twenty-five years. He is a chartered financial analyst and is currently a trustee of the Research Foundation of the CFA Institute.

Catherine James Paglia. Ms. Paglia has been a director/trustee on the Columbia RiverSource Boards since 2004. Ms. Paglia has extensive experience in the asset management industry, and currently serves as a director of Enterprise Asset Management, Inc., a private real estate and asset management company.

Leroy C. Richie. Mr. Richie has been a director/trustee on the Columbia RiverSource Boards since 2008. Mr. Richie has over twenty years of legal experience, including, currently, as Counsel at Lewis & Munday, P.C., and formerly served as Vice President and General Counsel, Automotive Legal Affairs, of Chrysler Corporation from 1990 to 1997.

Anthony M. Santomero. Dr. Santomero has been a trustee of certain trusts in the Columbia Fund Complex since 2008. Dr. Santomero has over thirty years of experience as a professor of finance and private consultant specializing in issues including risk management, financial restructuring, credit risk evaluation and management, and regulation. He has served as consultant to financial institutions and

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agencies in the U.S. and various countries in the European Union and the European Community itself, as well as institutions in various countries around the world. Additionally, Dr. Santomero has served as President and Chief Executive Officer of the Federal Reserve Bank of Philadelphia.

Minor M. Shaw. Ms. Shaw has served as a trustee of certain trusts in the Columbia Fund Complex since 2003. Ms. Shaw is the President of certain private companies and is a member of the board of Piedmont Natural Gas and Blue Cross and Blue Shield of South Carolina. Ms. Shaw also serves as an active member on the boards of numerous educational and public service organizations.

Alison Taunton-Rigby. Ms. Taunton-Rigby has been a director/trustee on the Columbia RiverSource Boards since 2002. Ms. Taunton-Rigby has been the Chief Executive Officer and a director of RiboNovix, Inc. since 2003. She also formerly served as the President of Aquila Biopharmaceuticals.

William F. Truscott. Mr. Truscott has been a director/trustee on the Columbia RiverSource Boards since 2001. Mr. Truscott has over nine years of experience as President and Chief Investment Officer of Columbia Management, and currently serves as Chairman of the board of Columbia Management. Mr. Truscott is also an executive officer of Ameriprise, the parent company of Columbia Management.

Procedures for Communications to the Columbia Nations Board

Shareholders who want to communicate with the Columbia Nations Board or an individual trustee should send written communications to c/o The Secretary of Columbia Funds Series Trust, One Financial Center, Boston, MA 02111, addressed to the Board of Trustees of the Trust or the individual trustee. The Secretary of the Trust may determine not to forward to the Columbia Nations Board or individual trustees any letter that does not relate to the business of a Fund.

Executive Officers of the Trust and Columbia Management

Information about the executive officers of the Trust and Columbia Management is included in Appendix C to this Joint Proxy Statement.

Remuneration for Trustees and Officers

The current trustees, each of whom is not an employee of Columbia Management or its affiliates, each receives an annual retainer fee of $110,000, which is shared by all of the funds overseen by such trustees. In addition, the current trustees are currently paid a total of $15,000 per Columbia Nations Board meeting ($2,500 for telephonic attendance at certain meetings), the amount of which is shared by all of the funds overseen by such trustees. The chairs of the Columbia Nations Board and its committees receive additional compensation for serving in such capacities. The trustees are also reimbursed for the expenses of attending meetings. Persons who are employees, officers or directors of Columbia Management receive no remuneration for serving as trustees of the Trust.

Under the terms of the Columbia Nations Board’s Deferred Compensation Agreement, each eligible trustee may elect, on an annual basis, to defer receipt of all or a portion of compensation payable to him or her for service as trustee for that calendar year. Fees deferred by a trustee are credited to a book reserve account established by the Funds, the value of which is derived from the rate of return of one or more of a subset of the funds in the Combined Fund Complex selected by the trustee (with accruals to such account beginning at such time as a trustee’s elections having been established, and fees for service having been paid into such account, and terminating at such time as when proceeds become payable to such trustee under the Deferred Compensation Agreement). Trustees may change their elections only in accordance with the provisions of the Deferred Compensation Agreement.

Distributions from a trustee’s book reserve account will be paid by check, either in a lump sum or in annual installments. Payments made in annual installments are disbursed over a period of up to ten years, following such time as a trustee may qualify to receive such payments. If a deferring trustee dies prior to or after the commencement of the disbursement of amounts accrued in his/her book reserve account, the

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balance of the account will be distributed to his/her designated beneficiary either in lump sum or in annual payments as established by such trustee himself/herself, his/her beneficiary or his/her estate. Amounts payable under the Deferred Compensation Agreement are not funded or secured in any way, and each deferring trustee has the status of an unsecured creditor of the funds overseen by such trustee.

Total fees paid by each Fund to the current trustees for the Funds’ last fiscal year are outlined in Appendix D to this Joint Proxy Statement.

Columbia Management pays all salaries of officers of the Trust, except for the Funds’ Chief Compliance Officer, a portion of whose salary is paid by the Trust.

Required Vote and Recommendation

Election of trustees requires the vote of a plurality of the votes cast at the Meeting by or on behalf of shareholders of the Trust at which a quorum is present or represented by proxy.

THE COLUMBIA NATIONS BOARD UNANIMOUSLY RECOMMENDS THAT YOU

VOTE FOR THE ELECTION OF EACH NOMINEE.

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PROPOSAL 2 – APPROVE AMENDMENT TO IMS AGREEMENT

Background

The Columbia Nations Board has unanimously approved an amendment to the Investment Management Services Agreement (the “IMS Agreement”) between Columbia Management and the Trust, on behalf of the IMS Fee Funds and the LifeGoal Portfolios. The proposed amendment is part of a larger group of proposals aimed at further integrating the Combined Fund Complex following the Transaction. Among other things, the proposed amendment is designed, together with these other proposals, to achieve consistent investment management service and fee structures across the Combined Fund Complex. Under the proposed amendment, the Funds would continue to be managed by Columbia Management and would receive services that are the same as the services provided under the current IMS Agreement. As further described below, however, the proposed amendment would affect the IMS Fee Funds and LifeGoal Portfolios in different ways:

A summary of the terms and provisions of the IMS Agreement follows. Additional details about the effects of the proposed amendment on particular Funds’ fee rates are set forth under “Changes to Investment Advisory Fee Rates” and “Board Considerations” below. Additional information about Columbia Management is provided in Appendix E.

Description of IMS Agreement

The current IMS Agreement is dated as of May 1, 2010 and was last submitted to a vote of shareholders of the Funds and the Trust at a joint special meeting of such shareholders that was held on March 3, 2010, as adjourned until March 31, 2010 for certain Funds (Columbia Marsico 21^st Century Fund, Columbia Small Cap Value Fund II, Columbia LifeGoal^® Balanced Growth Portfolio, Columbia LifeGoal^® Growth Portfolio and Columbia LifeGoal^® Income and Growth Portfolio) and until April 26,

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2010 for Columbia Global Value Fund. The joint special meeting was held in order to approve the IMS Agreement as a result of the closing of the Transaction, which resulted in the assignment (as that term is defined in the 1940 Act) and automatic termination of the Funds’ predecessor investment advisory agreement with the Funds’ predecessor investment adviser.

The IMS Agreement generally provides that, subject to oversight by the Columbia Nations Board and the authorized officers of the Funds, Columbia Management agrees to: continuously furnish the Funds with investment advice; decide what securities are to be purchased, held or sold, consistent with the Funds’ investment objectives, strategies and policies; perform investment research; prepare and make available to the Columbia Nations Board all research and statistical data in connection therewith; and execute or cause the execution of purchase and sell orders for the Funds. The IMS Agreement adds that Columbia Management will determine which investments to make consistent with the Fund’s investment strategies, recommend changes to investment objectives, strategies and policies to the Columbia Nations Board and furnish to such Board such reports, statistical data and other information relating to the investment management of the relevant Fund in the form and at such intervals that the Columbia Nations Board may reasonably request.

Under the IMS Agreement, Columbia Management, in executing portfolio transactions and selecting brokers or dealers for a Fund, agrees to seek best execution, except where otherwise directed by the Columbia Nations Board. In selecting broker-dealers to execute transactions, Columbia Management may consider not only the price of the security being traded (including commission or mark-up), but also other relevant facts such as, without limitation, the size and difficulty of the transaction, the characteristics of the security being traded, the broker-dealer’s financial condition and execution capabilities, or research or other information furnished to Columbia Management. The IMS Agreement explicitly contemplates that Columbia Management may, except where otherwise directed by the Columbia Nations Board, execute transactions or pay to a broker or dealer who provides brokerage and research services a commission for executing a portfolio transaction for the Fund that is in excess of the amount of commission another broker or dealer would have charged for effecting the transaction, to the extent consistent with applicable law.

The IMS Agreement contemplates the engagement by Columbia Management of subadvisers for the Funds, and provides that Columbia Management may sub contract for certain of the services described under the IMS Agreement, with the understanding that the quality and level of services required to be provided under the agreement will not be diminished thereby and with the understanding that Columbia Management will obtain the approval of the Columbia Nations Board and/or the Fund’s shareholders as required by applicable law, rules, regulations promulgated thereunder, the terms of the IMS Agreement, resolutions of the Columbia Nations Board and Columbia Management’s commitments.

The IMS Agreement contemplates that Columbia Management will provide support as required or requested by the Columbia Nations Board with respect to voting proxies solicited by or with respect to the issuers of securities owned by a Fund. The IMS Agreement also contemplates that Columbia Management may vote proxies and provide or withhold consents as directed by the Columbia Nations Board from time to time.

The IMS Agreement generally requires that all information provided by a Fund to Columbia Management and vice versa be treated as confidential and non-disclosable to unaffiliated third parties except under limited circumstances. The IMS Agreement generally requires books and records to be maintained by Columbia Management on behalf of a Fund.

Fees

Under the IMS Agreement, each Fund pays a fee that is based on a percentage of the daily net assets of the Fund. Out of this fee, Columbia Management is solely responsible for compensating any subadviser(s) for performing any of the duties delegated to them.

The aggregate amounts actually paid by each IMS Fee Fund and LifeGoal Portfolio to the predecessor investment manager pursuant to the predecessor investment advisory agreement (which

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included fee schedules identical to those currently in effect), during such Funds’ last fiscal year are set forth in Appendix F to this Joint Proxy Statement. To the extent required, Schedules of the current and proposed annual operating expenses of each IMS Fee Fund and each LifeGoal Portfolio whose investment advisory fee rate would be increasing under the proposed amendment to the IMS Agreement are also set forth in Appendix G-1 and Appendix G-2, respectively, to this Joint Proxy Statement. For other Funds, whose investment advisory fee rates and total management fee rates are not increasing, amounts paid and current and pro forma annual operating expense information are not included in this Joint Proxy Statement. Except for the fee rate changes described in this Proposal 2 and in Appendix G-1 and Appendix G-2, there are no proposed fee rate changes under the proposed amendment to the IMS Agreement that could or would result in an increase in the investment advisory fee rates payable under the IMS Agreement.

As noted below, Columbia Management has agreed to implement certain administration fee reductions and contractual expense limitations that will generally cap annual operating expense ratios at levels that are at or below the median net operating expense ratio of the other funds in the Fund’s respective peer group (as determined annually by an independent third-party data provider), pursuant to a methodology mutually agreed upon by the Columbia Nations Board and Columbia Management. These commitments may mitigate the impact of any fee increases resulting from any proposed investment advisory fee rate increases. Any contractual expense limitation may be revised or discontinued upon its expiration.

Payment of Expenses

The IMS Agreement requires Columbia Management to furnish at its expense the office space, supplies, equipment, clerical help and other personnel and services required to render its investment management services and to pay the compensation of the trustees or officers of the Fund who are directors, officers, or employees of Columbia Management (except to the extent that the Columbia Nations Board specifically approves the payment by the Fund of all or a portion of such compensation). The IMS Agreement specifically notes that, except to the extent expressly assumed by Columbia Management, and except to the extent required by law to be paid or reimbursed by Columbia Management, Columbia Management will have no duty to pay any Fund operating expenses incurred in the organization and operation of the Fund.

Limits of Liability

Under the IMS Agreement, and subject to U.S. federal securities laws, neither Columbia Management nor any of its directors, officers, partners, principals, employees or agents will be liable for any acts or omissions or for any loss suffered by a Fund or the Fund’s shareholders or creditors, except for a loss resulting from willful misfeasance, bad faith or negligence on its part in the performance of its duties under the IMS Agreement or reckless disregard of its obligations or duties under the IMS Agreement.

Proposal 2(a) – Changes to Investment Advisory Fee Rates

The Columbia Nations Board has approved, and recommends that shareholders of such IMS Fee Funds approve, an amendment to the IMS Agreement between Columbia Management and the Trust, on behalf of the IMS Fee Funds, that would increase the investment advisory fee rates payable by each IMS Fee Fund to Columbia Management at all or most asset levels. Except for the investment advisory fee rates payable, the IMS Agreement for such IMS Fee Fund would remain the same in all respects.

As indicated above, the proposed amendment to the IMS Agreement is part of a group of related proposals that are designed to enhance consistency and uniformity across the Combined Fund Complex. These proposals are intended to provide shareholders of the Combined Fund Complex with the potential to realize the full range of benefits resulting from a much larger mutual fund group, including:

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The investment advisory fee rates payable by the IMS Fee Funds at all or most asset levels and by the LifeGoal Portfolios on certain types of assets would increase, as described below. However, the net cumulative effect of the larger group of proposals is expected to be a reduction in the overall fees payable by the Combined Fund Complex. This will benefit many shareholders, especially since many shareholders own shares of more than one fund.

The increase in investment advisory fee rates would not necessarily result in higher gross expenses for such IMS Fee Funds in light of their current asset levels and because the fee rates payable to Columbia Management pursuant to its administration services agreement with the IMS Fee Funds are also being standardized and, at some asset levels, reduced as part of the overall plan to achieve consistent fee rates. The effect of the increase in investment advisory fee rates (which requires shareholder approval) and the contemporaneous reduction in administration fee rates (which does not require shareholder approval) is that, at most asset levels, for all of the IMS Fee Funds except Columbia Large Cap Enhanced Core Fund, investment advisory and administration fees on a combined basis will not exceed the combined fee rates currently in effect. The following chart provides additional information on a Fund-by-Fund basis about current and proposed investment advisory fee rates and administration fee rates for the IMS Fee Funds and illustrates the impact of the changes to investment advisory fee rates and administration fee rates on a consolidated basis.

Current and Proposed Management Fee Rates

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The fees shown in the above table do not account for any contractual expense limitation agreements between Columbia Management and the IMS Fee Funds. In this regard, Columbia Management has agreed to implement contractual expense limitations that will generally cap annual operating expense ratios for each IMS Fee Fund at levels that are at or below the median expense ratio of the other funds in the IMS Fee Fund’s respective peer group. These commitments may mitigate the impact of any fee changes resulting from the adoption of standardized fee schedules. Appendix G-1 shows the estimated impact of the changes to management fees on each IMS Fee Fund and the estimated impact of the expected fee caps. Any contractual expense limitation may be revised or discontinued upon its expiration. Also, with respect to Columbia Large Cap Enhanced Core Fund, Columbia Management has agreed to an additional fee waiver arrangement pursuant to which the proposed increase in management fees would be phased in over five years.

Each year, an independent third-party data provider will determine the median expense ratios of a Fund’s Class A shares peer group. The independent third-party data provider’s determination will then be used to adjust the contractual expense limitation for Class A shares of such Fund, if necessary. Corresponding contractual expense limitations (adjusted to reflect differences in transfer agency and/or distribution and service fees) will be implemented for other share classes. Actual fees and expenses will vary based upon the size of the Fund and other factors, and may be higher or lower than the estimates shown in Appendix G-1. The estimated proposed expense caps shown in Appendix G-1 reflect peer group median expense ratios as of early 2010, which are likely to change from year to year but will remain in place until at least [—], 2012. The amounts that would have been paid to Columbia Management by the IMS Fee Funds during the most recently completed fiscal year under the proposed investment advisory fee rates are also set forth in Appendix G-1.

Columbia Management has informed the Columbia Nations Board that the reductions in administration fee rates for each IMS Fee Fund are contingent on shareholder approval of the proposed amendment for that particular Fund. If shareholders of an IMS Fee Fund fail to approve the proposed amendment on behalf of such Fund, then Columbia Management will continue to serve as investment manager to the Fund pursuant to the IMS Agreement. All terms and conditions of the current IMS Agreement that are currently in effect, including the current investment advisory fee rates, would remain in effect. In addition, for such an IMS Fee Fund, there would be no corresponding reduction in administration fee rates as described above.

Proposal 2(b) – Changes to the Fee Structures of the LifeGoal Portfolios

The Columbia Nations Board has approved, and recommends that shareholders of such LifeGoal Portfolios approve, an amendment to the IMS Agreement between Columbia Management and the Trust, on behalf of the LifeGoal Portfolios, that would revise the fee structures of the LifeGoal Portfolios. Except for the investment advisory fee rates payable and, for certain LifeGoal Portfolios, the termination of the assumption agreement as described below, the IMS Agreement for such LifeGoal portfolio would remain the same in all respects.

Current Services Provided to, and Fee Structures of, the LifeGoal Portfolios

As indicated above, the proposed amendment is part of a group of related proposals that are designed to enhance consistency and uniformity across the Combined Fund Complex. For certain of the LifeGoal Portfolios, the proposed amendment also contemplates the termination of a related assumption agreement, and is aimed at “unbundling” their fee arrangements. Specifically, three of the LifeGoal Portfolios (Columbia LifeGoal^® Balanced Growth Portfolio, Columbia LifeGoal^® Growth Portfolio and Columbia LifeGoal^® Income & Growth Portfolio) (each, a “Bundled Portfolio” and collectively, the “Bundled Portfolios”) currently have bundled fee arrangements. Under these arrangements, Columbia Management receives an investment advisory fee for providing investment management services (0.25% of average daily net assets) and, pursuant to the related assumption agreement, has agreed to bear all other fees and expenses, except taxes, brokerage fees and commissions, costs (including interest expenses) of borrowing money, extraordinary expenses, and any applicable Rule 12b-1 fees, shareholder servicing fees

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and/or shareholder administration fees. Columbia LifeGoal^® Income Portfolio, does not currently have a bundled fee arrangement, and the investment advisory fee for this LifeGoal Portfolio is not payable on assets invested in other underlying Columbia Funds and is currently payable only on assets invested in individual securities and two Columbia Funds that do not currently pay investment advisory fees (Columbia Mortgage- and Asset-Backed Portfolio and Columbia Bond Portfolio). The investment advisory fee currently payable by Columbia LifeGoal^® Income Portfolio on those assets is 0.50%, though Columbia Management has contractually agreed to waive 0.10% of the advisory fees payable on such assets until July 31, 2011.

Proposed Services Provided to, and Fee Structures of, the LifeGoal Portfolios

The proposed amendment, which, for the Bundled Portfolios, also contemplates the termination of the related assumption agreement, would have the effect of: (i) unbundling the fee arrangements for the Bundled Portfolios (i.e., the Bundled Portfolios would pay separate fees for administration, custody, transfer agency, legal, audit, registration fees, etc.) and (ii) changing the investment advisory fee structure so that each LifeGoal Portfolio would pay different investment advisory fee rates depending on the type of assets (i.e., no fee on assets invested in underlying proprietary funds that pay a management fee to Columbia Management, a stated rate on assets invested in third party funds and a higher stated rate on assets invested directly in securities).

More specifically, if the proposed amendment is approved, the Bundled Portfolios would terminate the assumption agreement and change the investment advisory fees payable under the IMS Agreement. By “unbundling” its fee arrangements, the investment advisory fee rates for each of the three Bundled Portfolios would decrease on certain types of assets and increase on other types of assets, and the Bundled Portfolio would begin paying non-advisory expenses (including, but not limited to, administration, custody, transfer agency, legal, audit and SEC registration fees). Unbundling the Bundled Portfolios’ fee arrangements will provide greater clarity as to actual expenses incurred by the Bundled Portfolios. Under the amended IMS Agreement, Columbia Management will continue to provide the same investment management services to the Bundled Portfolios.

The proposed amendment would standardize the investment advisory fee rates paid by the LifeGoal Portfolios. No investment advisory fee would be payable by the LifeGoal Portfolios on underlying proprietary funds that already pay a management fee to Columbia Management. The LifeGoal Portfolios would pay (a) 0.55% on assets invested in securities other than third-party advised mutual funds and funds in the Combined Fund Complex that pay an advisory fee, including exchange-traded funds, derivatives and individual securities (Columbia LifeGoal^® Income Portfolio would pay 0.40% on such assets) and (b) 0.10% on assets invested in third-party advised mutual funds.

Appendix G-2 shows the estimated impact of the changes to the fee structures of each LifeGoal Portfolio and the estimated impact of expected fee caps. Columbia Management has agreed to implement contractual expense limitations that will generally cap annual operating expense ratios for each LifeGoal Portfolio at levels that are at or below the median expense ratio of the other funds in the LifeGoal Portfolio’s respective peer group. These commitments may mitigate the impact of any fee changes resulting from the adoption of standardized fee schedules. Appendix G-2 shows the estimated impact of the changes to management fees on each LifeGoal Portfolio and the estimated impact of the expected fee caps. Any contractual expense limitation may be revised or discontinued upon its expiration.

Each year, an independent third-party data provider will determine the median expense ratios of a LifeGoal Portfolio’s Class A shares peer group. The independent third-party data provider’s determination will then be used to adjust the contractual expense limitation for Class A shares of such Fund, if necessary. Corresponding contractual expense limitations (adjusted to reflect differences in transfer agency and/or distribution and service fees) will be implemented for other share classes. Actual fees and expenses will vary based upon the size of the LifeGoal Portfolio and other factors, and may be higher or lower than the estimates shown in Appendix G-2. The estimated proposed expense caps shown in Appendix G-2 reflect peer group median expense ratios as of early 2010, which are likely to change from year to year but will

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remain in place until at least [—], 2012. The amounts that would have been paid to Columbia Management by the IMS Fee Funds during the most recently completed fiscal year under the proposed investment advisory fee rates are also set forth in Appendix G-2.

If shareholders of a LifeGoal Portfolio fail to approve the proposed amendment on behalf of such LifeGoal Portfolio, then Columbia Management will continue to serve as investment manager of the LifeGoal Portfolio pursuant to the current IMS Agreement. All terms and conditions of the current IMS Agreement that are currently in effect, including the investment advisory fee rates and, for the Bundled Portfolios, the related assumption agreement, would remain in effect. In addition, for the Bundled Portfolios, the proposed expense limitations would not take effect.

Board Considerations

In September 2010, the Columbia Nations Board unanimously approved the amendment to the IMS Agreement on behalf of the IMS Fee Funds and the LifeGoal Portfolios. As detailed below, the Contracts Review Committee and/or the full Columbia Nations Board held numerous meetings and discussions with Columbia Management and reviewed and considered extensive materials in connection with the approval of the changes to the fee rates payable by the IMS Fee Funds and the fee structures of the LifeGoal Portfolios before determining to approve the amendment to the IMS Agreement.

Prior to approving the proposed changes to the fee rates payable by the IMS Fee Funds and the fee structures of the LifeGoal Portfolios, the trustees were presented with, and requested, received and evaluated, materials about the current IMS Agreement, the proposed changes to the fee rates and fee structures and related matters from Columbia Management. The trustees also reviewed reports prepared by Lipper, Inc., an independent provider of investment company data, which included information comparing the IMS Fee Funds’ and LifeGoal Portfolios’ current fees and expense ratios with a group of comparable funds that were selected by Lipper, Inc. Included in these reports were comparisons of contractual and actual investment advisory fee rates and total operating expenses.

In addition, the trustees considered that the proposed amendment was part of a larger group of proposals, aligning the fees and expenses for similar funds based on a more consistent and uniform pricing model for all funds in the family of funds. In this regard, the Columbia Nations Board recognized that many of the funds in the fund family were organized at different times by many different sponsors, and as a result, their fees and expenses did not reflect a common overall design.

The trustees also reviewed and considered information that they had previously received, addressing the services Columbia Management provides and fund performance, among other things, in connection with their most recent consideration and approval of the IMS Agreement. Moreover, the Columbia Nations Board and its Contract Review Committee met on several occasions, and received extensive materials, which the trustees considered relevant to their consideration and approval of the proposed changes to the fee rates payable by the IMS Fee Funds and the fee structures of the LifeGoal Portfolios. The trustees also consulted with the Non-Interested Trustees’ independent legal counsel, who advised on the legal standards for consideration by the trustees, and otherwise assisted the trustees in their deliberations.

At the conclusion of its review of the materials discussed above and of the discussions among the trustees leading up to and during the September 20, 2010 meetings, the Columbia Nations Board, on behalf of its respective Funds, agreed that it had been furnished with sufficient information to make an informed business decision with respect to approval of the amendment to the IMS Agreement.

In making its decision to approve the proposed amendment to the IMS Agreement for each IMS Fee Fund and each LifeGoal Portfolio, the Columbia Nations Board considered factors bearing on the nature, extent and quality of the services provided to such Fund, and the costs for those services, with a view toward making a business judgment as to whether the proposed amendment to the IMS Agreement is, under all of the circumstances, in the best interest of such Fund and the Fund’s shareholders. The factors that the trustees of the Columbia Nations Board considered and the conclusions that they, in their business judgment, reached included, principally, the following:

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In making its decision to approve the amendment to the IMS Agreement that included the increase of the investment advisory fee rates payable by each of the IMS Fee Funds at all or most asset levels, the factors that the trustees of the Columbia Nations Board considered and the conclusions that they reached included, principally, the following:

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In making its decision to approved the amendment to the IMS Agreement that would change the fee structures of each LifeGoal Portfolio, and which contemplates, for the Bundled Portfolios, the termination of the related assumption agreement, the factors that the trustees considered and the conclusions that they reached included, principally, the following:

In their deliberations, the trustees of the Columbia Nations Board did not identify any single item that was paramount or controlling and individual trustees may have attributed different weights to various factors. The trustees also evaluated all information available to them on a Fund-by-Fund basis, and their determinations were made separately in respect of each IMS Fee Fund and LifeGoal Portfolio. Based on the foregoing, and other relevant information received, the trustees concluded that the proposed investment advisory fee rate increases for each IMS Fee Fund and the proposed fee structures for each LifeGoal Portfolio are acceptable and competitive, including when compared to similar funds in the industry. Accordingly, the Columbia Nations Board unanimously approved the amendment to the IMS Agreement with respect to the IMS Fee Funds and the LifeGoal Portfolios and unanimously recommends that shareholders of such Funds vote “FOR” the approval of the amendment.

Required Vote and Recommendation

For each IMS Fee Fund and LifeGoal Portfolio, approval of the amendment to the IMS Agreement requires the affirmative vote of a “majority of the outstanding voting securities” of the Fund, which for this purpose means the affirmative vote of the lesser of (i) more than 50% of the outstanding voting securities of the Fund or (ii) 67% or more of the outstanding voting securities of such Fund present at the Meeting if more than 50% of the outstanding voting securities of the Fund are present at the Meeting in person or represented by proxy. All shares of an IMS Fee Fund or LifeGoal Portfolio vote together as a single class on Proposal 2. Each Fund’s shareholders vote separately from each other Fund’s shareholders on Proposal 2.

THE COLUMBIA NATIONS BOARD UNANIMOUSLY RECOMMENDS THAT YOU

VOTE FOR THE APPROVAL OF THE PROPOSED AMENDMENT TO THE

IMS AGREEMENT.

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PROXY VOTING AND SHAREHOLDER MEETING INFORMATION

Proxy Solicitation

If you properly authorize your proxy through the internet or telephonically, or by executing and returning the enclosed Proxy Card, and your proxy is not subsequently revoked, your votes will be cast at the Meeting. If you give instructions, your votes will be cast in accordance with your instructions. If you return your signed Proxy Card without instructions, your votes will be cast (i) FOR the election of the 16 Nominees to serve as trustees on the Columbia Nations Board (Proposal 1); and (ii) FOR the approval of the proposed amendment to the IMS Agreement between the Trust, on behalf of the IMS Fee Funds and the LifeGoal Portfolios, and Columbia Management, which provides for an increase in the investment advisory fee rate payable by each of the IMS Fee Funds or certain changes to the fee structure of the LifeGoal Portfolios (Proposal 2). Your votes will be cast in the discretion of the proxy holders on any other matter that may properly come before the Meeting, including, but not limited to, proposing and/or voting on the adjournment of the Meeting with respect to one or both proposals in the event that a quorum is not obtained and/or sufficient votes in favor of either proposal are not received. Not all proposals affect each Fund, and shareholders of a Fund will only be entitled to cast votes and authorize proxies on those proposals affecting the Fund in which they are shareholders. Neither proposal is contingent on the other. In addition, approval of Proposal 2 by one IMS Fee Fund or LifeGoal Portfolio is not contingent on the approval of Proposal 2 by any other IMS Fee Fund or LifeGoal Portfolio.

Revocation of Proxy

If you execute and submit a proxy, you may revoke that proxy or change it by written notice to Computershare Fund Services at [—], by submitting a subsequently executed and dated Proxy Card, by authorizing your proxy by telephone or internet at a later date, or by attending the Meeting and casting your vote in person, or as otherwise permitted. Attending the Meeting in person will not automatically revoke your prior proxy. If you intend to vote in person at the Meeting, please call [—] to obtain important information regarding your attendance at the Meeting, including directions.

Quorum and Methods of Tabulation

Thirty-three and one-third percent (33.3%) of the shares of a Fund or the Trust as a whole entitled to vote, present in person or by proxy, constitutes a quorum of such Fund or the Trust as a whole, respectively. Abstentions and “broker non-votes” (i.e., shares held of record by a financial intermediary, such as a broker, or nominee, typically in “street name,” as to which proxies have been returned but (i) instructions have not been received from the beneficial owners or persons entitled to vote and (ii) the broker or nominee does not have discretionary voting power on a particular matter) will be treated as present for purposes of determining a quorum. A quorum of shareholders of the Trust is required to take action on the election of the 16 Nominees to the Columbia Nations Board (Proposal 1). Separately, a quorum of each IMS Fee Fund and each LifeGoal Portfolio is required to take action on the amendment to the IMS Agreement with respect to such IMS Fee Fund or LifeGoal Portfolio (Proposal 2).

In the event that a quorum of shareholders of a Fund or the Trust is not present at the Meeting or, even if such a quorum is so present, in the event that sufficient votes in favor of any proposal are not received and tabulated prior to the time the Meeting is called to order, the Meeting may be adjourned with respect to one or more Funds or the Trust and/or with respect to one or more proposals by the vote of a majority of the shares represented at the Meeting, either in person or by proxy, and further solicitations may be made.

Shareholders of record of each Fund at the close of business on December 17, 2010 (the “Record Date”) are entitled to notice of, and to vote at, the Meeting. The number of outstanding shares of each class of shares of each Fund held on the Record Date is listed in Appendix H. Shareholders of each Fund are entitled to one vote for each share and a proportionate fractional vote for each fractional share outstanding on the Record Date.

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Required Vote

The election of trustees (Proposal 1) requires the affirmative vote of a plurality of votes cast at the Meeting by or on behalf of shareholders of the Trust. A “plurality of votes cast” means that a Nominee is elected if he or she receives the highest number of affirmative votes cast, whether or not such votes constitute a majority, up to the maximum number of trustees to be elected at the Meeting, which is 16. All shares of the Trust vote together as a single class on Proposal 1.

For each IMS Fee Fund and each LifeGoal Portfolio, approval of Proposal 2 requires the affirmative vote of a “majority of the outstanding voting securities” of the IMS Fee Fund or LifeGoal Portfolio, which for this purpose means the affirmative vote of the lesser of (i) more than 50% of the outstanding voting securities of the Fund or (ii) 67% or more of the outstanding voting securities of the Fund that are present at the Meeting if more than 50% of the outstanding voting securities of such Fund are present at the Meeting in person or represented by proxy. All shares of an IMS Fee Fund or LifeGoal Portfolio vote together as a single class on Proposal 2, and each IMS Fee Fund’s and each LifeGoal Portfolio’s shareholders vote separately from shareholders of other IMS Fee Funds or LifeGoal Portfolios on Proposal 2.

Effect of Abstentions and Broker Non-Votes

For all matters to be voted upon, an abstention or broker non-vote will not be considered a vote cast, however, an abstention or broker non-vote will be counted for purposes of attaining a quorum. With respect to Proposal 1, abstentions and broker non-votes will have no effect on the outcome of the vote. Abstentions and broker non-votes will have the same effect as a vote against Proposal 2 in respect of each Fund entitled to vote thereon.

Annual Meetings and Shareholder Proposals

The Trust does not regularly hold annual meetings of shareholders but may from time to time schedule special meetings. The Trust last called a shareholder meeting to elect trustees and approve the current IMS Agreement in March of this year. The Governance Committee of the Columbia Nations Board typically will consider trustee candidates submitted by shareholders or from other sources as it deems appropriate. Any recommendation should be submitted to the Funds (Attention: Secretary). To be timely for consideration by the Governance Committee, the submission, including all required information, must be submitted in writing not less than 120 days before the date of the proxy statement for the previous year’s annual meeting of shareholders, if such a meeting is held. Otherwise, such submission shall be subject to the timeline requirements set forth below for submission of other shareholder proposals. The Governance Committee will consider only one candidate submitted by such a shareholder or group for nomination for election at a meeting of shareholders. The Governance Committee will not consider self-nominated candidates or candidates nominated by members of a candidate’s family, including such candidate’s spouse, children, parents, uncles, aunts, grandparents, nieces and nephews.

Any submission should include, at a minimum, the following information as to each individual proposed for election as a trustee: the name, age, business address, residence address and principal occupation or employment of such individual, the class, series and number of shares of stock of any Fund that are beneficially owned by such individual, the date such shares were acquired and the investment intent of such acquisition, whether such shareholder believes such individual would or would not qualify as a Non-Interested Trustee, and information regarding such individual that is sufficient, in the discretion of the Governance Committee, to make such determination, and all other information relating to such individual that is required to be disclosed in solicitation of proxies for election of trustees in an election contest (even if an election contest is not involved) or is otherwise required, in each case pursuant to Regulation 14A (or any successor provision) under the Exchange Act and the rules and regulations promulgated thereunder (including such individual’s written consent to being named in a proxy statement as a nominee and to serving as a trustee (if elected)). See “Proposal 1 – Current Committees of the Columbia Nations Board – Governance Committee” for more information.

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Shareholder submissions will be considered for inclusion in a proxy statement only if submitted by a date not earlier than the 365th calendar day before, and not later than the 60th calendar day before, the date on which the Columbia Nations Board has set a meeting date for the shareholder meeting at which the election of trustees is to be considered. The anticipated date of the next meeting to elect trustees is February 2016. The submission of a proposal does not guarantee its inclusion in a proxy statement and is subject to the limitations of U.S. federal securities laws. Shareholders may submit proposals in writing to c/o The Secretary of Columbia Funds Series Trust, One Financial Center, Boston, Massachusetts 02111-2621.

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OTHER INFORMATION

Current Service Providers

Columbia Management, located at One Financial Center, Boston, Massachusetts 02111, serves as the investment manager and administrator of the Funds. Columbia Management Investment Distributors, Inc., also located at One Financial Center, Boston, Massachusetts 02111, serves as the principal underwriter of the Funds. Please see Appendix I for information regarding the aggregate amount of commissions paid by each Fund to any affiliated brokers during its most recent fiscal year.

Special Note for Shareholders of the Feeder Fund

The Feeder Fund, Columbia International Value Fund, is a feeder fund in a master/feeder structure, meaning that it invests all or substantially all of its net investable assets in the Master Portfolio. One other feeder fund also owns interests in the Master Portfolio.

The interestholders of the Master Trust also are being asked to elect the 16 Nominees to the Master Trust Board. As an interestholder in the Master Portfolio, the Feeder Fund is “passing-through” this trustee election vote to Feeder Fund shareholders via this proxy solicitation, and will vote its interests in the Master Portfolio in the same proportion as shares of Feeder Fund shareholders for which it receives proper instructions. In this manner, shareholders of the Feeder Fund also will indirectly consider and vote on Proposal 1 with respect to the Master Trust. The trustee election proposal (Proposal 1) requires the affirmative vote of a majority of the interestholders of the Master Trust present at the Meeting.

As is noted above, in order to avoid confusion in terms throughout this Joint Proxy Statement, the terms “Fund” or “Funds” include the Master Portfolio, the term “Trust” includes the Master Trust, and the term “Columbia Nations Board” includes the Board of the Master Trust.

Other Matters to Come Before the Meeting

Columbia Management does not know of any matters to be presented at the Meeting other than those described in this Joint Proxy Statement. If other business should properly come before the Meeting, the persons named as proxies will vote thereon in accordance with their best judgment.

Principal Shareholders

Appendix J to this Joint Proxy Statement lists the persons that, to the knowledge of the Funds, owned beneficially 5% or more of the outstanding shares of any class of any Fund as of September 30, 2010. A shareholder who owns beneficially, directly or indirectly, more than 25% of any Fund’s voting securities is presumed to be a “control person” (as defined in the 1940 Act) of such Fund. The Nominees and officers of each Fund, in the aggregate, owned less than 1% of each class of each Fund’s outstanding shares as of September 30, 2010.

Expenses and Solicitation Activities

The expenses incurred in connection with the solicitation of proxies for the Meeting, including preparation, filing, printing, mailing and solicitation expenses, legal fees, out-of-pocket expenses and expenses of any proxy solicitation firm, will be paid separately by Columbia Management or an affiliated company and not by the Funds. In addition to the use of the mails, proxies may be solicited personally or via facsimile, telephone or the Internet by trustees, officers and employees of the Trust, Columbia Management or Columbia Management Investment Distributors, Inc. The Funds have engaged Computershare Fund Services to assist in soliciting at an estimated cost of approximately $[—], which will be paid by Columbia Management or an affiliated company. The material terms of the contract with Computershare Fund Services are [—].

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Joint Proxy Statement Delivery

“Householding” is the term used to describe the practice of delivering one copy of a document to a household of shareholders instead of delivering one copy of a document to each shareholder in the household. Shareholders of the Funds who share a common address and who have not opted out of the householding process should receive a single copy of the Joint Proxy Statement together with one Proxy Card for each account. If you received more than one copy of the Joint Proxy Statement, you may elect to household in the future; if you received a single copy of the Joint Proxy Statement, you may opt out of householding in the future; and you may, in any event, obtain an additional copy of this Joint Proxy Statement by writing to the appropriate Fund at the following address: One Financial Center, Boston, Massachusetts 02111.

Shareholder Reports

The Funds’ most recent semi-annual and annual reports previously have been mailed to shareholders. Each Fund will furnish, without charge, a copy of its most recent annual report and, if available, its most recent semiannual report subsequent to such annual report, to its shareholders on request. Additional copies of any of these documents are available by writing Columbia Management Investment Services Corp., P.O. Box 8081, Boston, MA 02266-8081, by calling (800) 345-6611 or by visiting www.columbiamanagement.com. All of these documents also are filed with the SEC and available on the SEC’s website at www.sec.gov.

PROMPT EXECUTION AND RETURN OF THE ENCLOSED PROXY CARD IS REQUESTED. A PRE-ADDRESSED, POSTAGE-PAID ENVELOPE IS ENCLOSED FOR YOUR CONVENIENCE, AND TELEPHONE AND INTERNET VOTING IS AVAILABLE.

It is important that you authorize proxies promptly. All shareholders, including those who expect to attend the Meeting in person, are urged to authorize their proxy as soon as possible by accessing the Internet site listed on the enclosed Proxy Card, by calling the toll-free number listed on the enclosed Proxy Card, or by mailing the enclosed Proxy Card in the enclosed return envelope, which requires no postage if mailed in the United States. [To enter the Meeting, you will need proof of ownership of the shares of the relevant Fund, such as your Proxy Card (or a copy thereof) or, if your shares are held of record by a financial intermediary, such as a broker, or nominee, a Proxy Card from the record holder or other proof of beneficial ownership, such as a brokerage statement showing your holdings of the shares of the relevant Fund.]

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APPENDIX A

Share Ownership of Nominees

As of September 30, 2010, the Nominees and officers of the Trust, as a group, beneficially owned less than 1% of each class of shares of each Fund. The tables below show, for each Nominee, the amount of shares of each Fund beneficially owned by the Nominee. They also show the aggregate value of all investments in shares of the Combined Fund Complex overseen or to be overseen by the Nominees, including notional amounts through the Deferred Compensation Agreement. Ownership information is presented in the following ranges: A = $0; B = $1-$10,000; C = $10,001-$50,000; D = $50,001-$100,000; and E = over $100,000.

Non-Interested Nominee Ownership as of September 30, 2010

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