Exhibit 99.B(d)(18)

                 AMENDMENT TO INVESTMENT SUB-ADVISORY AGREEMENT

     Amendment dated as of July 1, 2003 to the Investment Sub-Advisory Agreement
between SEI Investments Management Corporation (the "Adviser") and Capital
Guardian Trust Company (the "Sub-Adviser") with respect to the SEI Institutional
International Trust's International Equity Portfolio (the "Portfolio").

                                   WITNESSETH:

     WHEREAS, Adviser and Sub-Adviser have entered into an Investment
Sub-Advisory Agreement (the "Agreement") dated June 29, 1998, pursuant to which
the Sub-Adviser renders investment sub-advisory services to the Portfolio;

     WHEREAS, Section 1(h) of the Agreement provides that (i) the Sub-Adviser
shall review all proxy solicitation materials and be responsible for voting and
handling all proxies in relation to the securities held as Assets in the
Portfolio; and (ii) the Adviser shall instruct the custodian and other parties
providing services to the Portfolio to promptly forward misdirected proxies to
the Sub-Adviser;

     WHEREAS, the Adviser and the Sub-Adviser desire to amend Section 1(h) of
the Agreement for the purpose of revising the duties and responsibilities of the
Adviser and Sub-Adviser with regard to reviewing proxy solicitation materials
and responsibility for voting and handling proxies in relation to the securities
held as Assets in the Portfolio; and

     WHEREAS, the Adviser and Sub-Adviser also desire to amend certain
provisions of the Agreement to reflect amendments by the U.S. Securities and
Exchange Commission to Rules 10f-3, 12d3-1 and 17e-1 and adoption of new Rule
17a-10 under the Investment Company Act of 1940, as amended.

     NOW THEREFORE, in consideration of the foregoing and the mutual covenants
herein contained, the parties hereby agree as follows:

     Section 1(h) of the Agreement is amended and restated as follows:

     (h)    (i)    Except under the circumstances set forth in subsection (ii),
                   the Sub-Adviser shall not be responsible for reviewing proxy
                   solicitation materials or voting and handling proxies in
                   relation to the securities held as Assets in the Portfolio.
                   The Sub-Adviser shall instruct the custodian and other
                   parties providing services to the Portfolio to promptly
                   forward misdirected proxies to the Adviser.

            (ii)   The Sub-Adviser hereby agrees that upon 60 days' written
                   notice from the Adviser, the Sub-Adviser shall assume
                   responsibility for reviewing proxy solicitation materials and
                   voting proxies in relation to the securities held as Assets
                   in the Portfolio in accordance with the Sub-Adviser's Proxy
                   Voting Policies and

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                   Procedures, as they may be amended from time to time. As of
                   the time as the Sub-Adviser shall assume such
                   responsibilities with respect to proxies under this
                   sub-section (ii), the Adviser shall instruct the custodian
                   and other parties providing services to the Portfolio to
                   promptly forward misdirected proxies to the Sub-Adviser.

     The following paragraph is added to the Agreement as Section 1(i):

     (i)    In performance of its duties and obligations under this Agreement,
            the Sub-Adviser shall not consult with any other sub-adviser to the
            Portfolio or a sub-adviser to a portfolio that is under common
            control with the Portfolio concerning the Assets, except as
            permitted by the policies and procedures of the Portfolio. The
            Sub-Adviser shall not provide investment advice to any assets of the
            Portfolio other than the Assets.

     Except as expressly superseded or modified by this Amendment, the terms and
provisions of the Agreement shall continue to apply with full force and effect.

     IN WITNESS WHEREOF, the parties have caused this Amendment to be executed
by their officers designated below as of the day and year first written above.

SEI INVESTMENTS MANAGEMENT CORPORATION      CAPITAL GUARDIAN TRUST COMPANY

By:    /s/ Todd Cipperman                   By:    /s/ Stephen E. Embs
       ------------------------------              ---------------------------
Name:  Todd Cipperman                       Name:  Stephen E. Embs
       ------------------------------              ---------------------------
Title: Senior Vice President                Title: Vice President
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