Exhibit (6)(a)

                                 GATEWAY FUND

                              Advisory Agreement

   AGREEMENT made the 16th day of February, 2008, by and between THE GATEWAY
TRUST, a Massachusetts business trust (the "Fund"), with respect to its Gateway
Fund series (the "Series"), and Gateway Investment Advisers, LLC, a Delaware
limited liability company (the "Manager").

                                  WITNESSETH:

   WHEREAS, the Fund and the Manager wish to enter into an agreement setting
forth the terms upon which the Manager (or certain other parties acting
pursuant to delegation from the Manager) will perform certain services for the
Series;

   NOW, THEREFORE, in consideration of the premises and covenants hereinafter
contained, the parties agree as follows:

   1. (a) The Fund hereby employs the Manager to furnish the Fund with
   Portfolio Management Services (as defined in Section 2 hereof) and
   Administrative Services (as defined in Section 3 hereof), subject to the
   authority of the Manager to delegate any or all of its responsibilities
   hereunder to other parties as provided in Sections 1(b) and (c) hereof. The
   Manager hereby accepts such employment and agrees, at its own expense, to
   furnish such services (either directly or pursuant to delegation to other
   parties as permitted by Sections 1(b) and (c) hereof) and to assume the
   obligations herein set forth, for the compensation herein provided;
   provided, however, that the Manager shall have no obligation to pay the fees
   of any Sub-Adviser (as defined in Section 1(b) hereof), to the extent that
   the Fund has agreed, under any contract to which the Fund and the
   Sub-Adviser are parties (a "Sub-Advisory Agreement") to pay such fees. The
   Manager shall, unless otherwise expressly provided or authorized, have no
   authority to act for or represent the Fund in any way or otherwise be deemed
   an agent of the Fund.

      (b) The Manager may delegate any or all of its responsibilities hereunder
   with respect to the provision of Portfolio Management Services (and
   assumption of related expenses) to one or more other parties (each such
   party, a "Sub-Adviser"), pursuant in each case to a written agreement with
   such Sub-Adviser that meets the requirements of Section 15 of the Investment
   Company Act of 1940 and the rules thereunder (the "1940 Act") applicable to
   contracts for service as investment adviser of a registered investment
   company (including without limitation the requirements for approval by the
   trustees of the Fund and the shareholders of the Series), subject, however,
   to such exemptions as may be granted by the Securities and Exchange
   Commission. Any Sub-Adviser may (but need not) be affiliated with the
   Manager. If different Sub-Advisers are engaged to provide Portfolio
   Management Services with respect to different segments of the portfolio of
   the Series, the Manager shall determine, in the manner described in the
   prospectus of the Series from time to time in effect, what portion of the
   assets belonging to the Series shall be managed by each Sub-Adviser.



      (c) The Manager may delegate any or all of its responsibilities hereunder
   with respect to the provision of Administrative Services to one or more
   other parties (each such party, an "Administrator") selected by the Manager.
   Any Administrator may (but need not) be affiliated with the Manager.

   2. As used in this Agreement, "Portfolio Management Services" means
management of the investment and reinvestment of the assets belonging to the
Series, consisting specifically of the following:

      (a) obtaining and evaluating such economic, statistical and financial
   data and information and undertaking such additional investment research as
   shall be necessary or advisable for the management of the investment and
   reinvestment of the assets belonging to the Series in accordance with the
   Series' investment objectives and policies;

      (b) taking such steps as are necessary to implement the investment
   policies of the Series by purchasing and selling of securities, including
   the placing of orders for such purchase and sale; and

      (c) regularly reporting to the Board of Trustees of the Fund with respect
   to the implementation of the investment policies of the Series.

   3. As used in this Agreement, "Administrative Services" means the provision
to the Fund, by or at the expense of the Manager, of the following:

      (a) office space in such place or places as may be agreed upon from time
   to time by the Fund and the Manager, and all necessary office supplies,
   facilities and equipment;

      (b) necessary executive and other personnel for managing the affairs of
   the Series (exclusive of those related to and to be performed under contract
   for custodial, transfer, dividend and plan agency services by the entity or
   entities selected to perform such services and exclusive of any managerial
   functions described in Section 4);

      (c) compensation, if any, of trustees of the Fund who are directors,
   officers or employees of the Manager, any Sub-Adviser or any Administrator
   or of any affiliated person (other than a registered investment company) of
   the Manager, any Sub-Adviser or any Administrator; and

      (d) if the Manager has delegated to one or more Sub-Advisers any or all
   of its responsibilities hereunder with respect to the provision of Portfolio
   Management Services, the Manager shall continue to be responsible for the
   supervision and oversight of the Portfolio Management Services provided by
   each Sub-Adviser, and oversight of all matters relating to compliance by the
   Fund with applicable laws and with the Series' investment policies,
   restrictions and guidelines.

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   4. Nothing in section 3 hereof shall require the Manager to bear, or to
reimburse the Fund for:

      (a) any of the costs of printing and mailing the items referred to in
   sub-section (n) of this section 4;

      (b) any of the costs of preparing, printing and distributing sales
   literature;

      (c) compensation of trustees of the Fund who are not directors, officers
   or employees of the Manager, any Sub-Adviser or any Administrator or of any
   affiliated person (other than a registered investment company) of the
   Manager, any Sub-Adviser or any Administrator;

      (d) registration, filing and other fees in connection with requirements
   of regulatory authorities;

      (e) the charges and expenses of any entity appointed by the Fund for
   custodial, paying agent, shareholder servicing and plan agent services;

      (f) charges and expenses of independent accountants retained by the Fund;

      (g) charges and expenses of any transfer agents and registrars appointed
   by the Fund;

      (h) brokers' commissions and issue and transfer taxes chargeable to the
   Fund in connection with securities transactions to which the Fund is a party;

      (i) taxes and fees payable by the Fund to federal, state or other
   governmental agencies;

      (j) any cost of certificates representing shares of the Fund;

      (k) legal fees and expenses in connection with the affairs of the Fund,
   including registering and qualifying its shares with Federal and State
   regulatory authorities;

      (l) expenses of meetings of shareholders and trustees of the Fund;

      (m) interest, including interest on borrowings by the Fund;

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      (n) the costs of services, including services of counsel, required in
   connection with the preparation of the Fund's registration statements and
   prospectuses, including amendments and revisions thereto, annual, semiannual
   and other periodic reports of the Fund, and notices and proxy solicitation
   material furnished to shareholders of the Fund or regulatory authorities; and

      (o) the Fund's expenses of bookkeeping, accounting, auditing and
   financial reporting, including related clerical expenses.

   5. All activities undertaken by the Manager or any Sub-Adviser or
Administrator pursuant to this Agreement shall at all times be subject to the
supervision and control of the Board of Trustees of the Fund, any duly
constituted committee thereof or any officer of the Fund acting pursuant to
like authority.

   6. The services to be provided by the Manager and any Sub-Adviser or
Administrator hereunder are not to be deemed exclusive and the Manager and any
Sub-Adviser or Administrator shall be free to render similar services to
others, so long as its services hereunder are not impaired thereby.

   7. As full compensation for all services rendered, facilities furnished and
expenses borne by the Manager hereunder, the Fund shall pay the Manager
compensation in an amount equal to (x) the annual rate of 0.65% of the first $5
billion and 0.60% of amounts in excess of $5 billion (or such lesser amount as
the Manager may from time to time agree to receive) minus (y) any fees payable
by the Fund, with respect to the period in question, to any one or more
Sub-Advisers pursuant to any Sub-Advisory Agreements in effect with respect to
such period. Such compensation shall be payable monthly in arrears or at such
other intervals, not less frequently than quarterly, as the Board of Trustees
of the Fund may from time to time determine and specify in writing to the
Manager. The Manager hereby acknowledges that the Fund's obligation to pay such
compensation is binding only on the assets and property belonging to the Series.

   8. It is understood that any of the shareholders, trustees, officers,
employees and agents of the Fund may be a shareholder, director, officer,
employee or agent of, or be otherwise interested in, the Manager, any
affiliated person of the Manager, any organization in which the Manager may
have an interest or any organization which may have an interest in the Manager;
that the Manager, any such affiliated person or any such organization may have
an interest in the Fund; and that the existence of any such dual interest shall
not affect the validity hereof or of any transactions hereunder except as
otherwise provided in the Agreement and Declaration of Trust of the Fund, the
partnership agreement of the Manager or specific provisions of applicable law.

   9. This Agreement shall become effective as of the date of its execution, and

      (a) unless otherwise terminated, this Agreement shall continue in effect
   for two years from the date of execution, and from year to year thereafter
   so long as such continuance is specifically approved at least annually
   (i) by the Board of Trustees of the Fund or by vote of a majority of the
   outstanding voting securities of the Series, and (ii) by vote of a majority
   of the trustees of the Fund who are not interested persons of the Fund or
   the Manager, cast in person at a meeting called for the purpose of voting
   on, such approval;

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      (b) this Agreement may at any time be terminated on sixty days' written
   notice to the Manager either by vote of the Board of Trustees of the Fund or
   by vote of a majority of the outstanding voting securities of the Series;

      (c) this Agreement shall automatically terminate in the event of its
   assignment;

      (d) this Agreement may be terminated by the Manager on ninety days'
   written notice to the Fund;

   Termination of this Agreement pursuant to this Section 10 shall be without
the payment of any penalty.

   10. This Agreement may be amended at any time by mutual consent of the
parties, provided that such consent on the part of the Fund shall have been
approved by vote of a majority of the trustees of the Fund who are not
interested persons of the Fund or the Manager, cast in person at a meeting
called for the purpose of voting on such approval, and, to the extent required
by law, by vote of a majority of the outstanding voting securities of the
Series.

   11. For the purpose of this Agreement, the terms "vote of a majority of the
outstanding voting securities," "interested person," "affiliated person" and
"assignment" shall have their respective meanings defined in the 1940 Act,
subject, however, to such exemptions as may be granted by the Securities and
Exchange Commission under the 1940 Act. References in this Agreement to any
assets, property or liabilities "belonging to" the Series shall have the
meaning defined in the Fund's Agreement and Declaration of Trust as amended
from time to time.

   12. In the absence of willful misfeasance, bad faith or gross negligence on
the part of the Manager, or reckless disregard of its obligations and duties
hereunder, the Manager shall not be subject to any liability to the Fund, to
any shareholder of the Fund or to any other person, firm or organization, for
any act or omission in the course of, or connected with, rendering services
hereunder.

   13. In accordance with Regulation S-P, if non-public personal information
regarding either party's customers or consumers is disclosed to the other party
in connection with this Agreement, the party receiving such information will
not disclose or use that information other than as necessary to carry out the
purposes of this Agreement.

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   IN WITNESS WHEREOF, the parties hereto have executed this Agreement on the
day and year first above written.

THE GATEWAY TRUST
on behalf of its Gateway Fund series


By: /s/ Coleen Downs Dinneen
    ------------------------------------
    Name: Coleen Downs Dinneen
    Title: Secretary, Clerk and Chief
           Legal Officer

GATEWAY INVESTMENT ADVISERS, LLC


By: /s/ J. Patrick Rogers
    ------------------------------------
    Name: J. Patrick Rogers
    Title: President

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                                    NOTICE

   A copy of the Agreement and Declaration of Trust establishing The Gateway
Trust (the "Fund") is on file with the Secretary of The Commonwealth of
Massachusetts, and notice is hereby given that this Agreement is executed with
respect to the Fund's Gateway Fund series (the "Series") on behalf of the Fund
by officers of the Fund as officers and not individually and that the
obligations of or arising out of this Agreement are not binding upon any of the
trustees, officers or shareholders individually but are binding only upon the
assets and property belonging to the Series.