SEI INSTITUTIONAL INTERNATIONAL TRUST

                           INTERNATIONAL EQUITY FUND

                     SUPPLEMENT DATED JUNE 25, 1999 TO THE
           CLASS A AND CLASS D PROSPECTUSES DATED SEPTEMBER 30, 1998

THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT CONTAINED IN
THE PROSPECTUSES, AND SHOULD BE READ IN CONJUNCTION WITH SUCH PROSPECTUSES.

The Board of Trustees of SEI Institutional International Trust (the "Trust"),
including all of the Trustees who are not "interested persons" of the Trust,
have appointed Oechsle International Advisors, LLC ("Oechsle"), as a Sub-Adviser
to the Trust's International Equity Fund (the "Fund"). Oechsle was approved as a
Sub-Adviser at the Quarterly Meeting of the Board of Trustees held on June
21-22, 1999, and its appointment does not require Shareholder approval. This
procedure for adding or replacing Sub-Advisers was approved by the Trust's
Shareholders on June 16, 1995, and was authorized by an exemptive order issued
to the Trust by the Securities and Exchange Commission on April 29, 1996.

In evaluating Oechsle, the Trustees received written and oral information from
SEI Investments Management Corporation ("SIMC") and Oechsle. SIMC recommended
the selection of Oechsle and reviewed the considerations and the search process
that led to its recommendation. The Trustees also met with representatives of
Oechsle and considered information about portfolio managers, investment
philosophy, strategies and process, as well as its performance track record,
among other factors. In appointing Oechsle, the Trustees carefully evaluated:
(1) the nature and quality of the services expected to be rendered to the Fund
by Oechsle; (2) the distinct investment process of Oechsle; (3) the history,
reputation, qualification and background of Oechsle's personnel and its
financial condition; (4) its performance record; and (5) other factors deemed
relevant. The Trustees also reviewed the fees to be paid to Oechsle, including
any benefits to be received by Oechsle or its affiliates in connection with soft
dollar arrangements.

Under the Investment Sub-Advisory Agreement ("Sub-Advisory Agreement") between
SIMC (the "Adviser") and Oechsle relating to the Fund, Oechsle makes investment
decisions for the assets of the Fund allocated to Oechsle by SIMC, and
continuously reviews, supervises and administers the Fund's investment program
with respect to these assets. Oechsle is independent of SIMC and discharges its
responsibilities subject to the supervision of SIMC and the Trustees of the
Trust and in a manner consistent with the Fund's investment objectives, policies
and limitations. The Sub-Advisory Agreement is substantially similar to those in
existence between the Adviser and the Trust's other sub-advisers. Specifically,
the duties to be performed under such agreement are similar, and the standard of
care and termination provisions of the Agreement are identical, to the other
agreements. The Sub-Advisory Agreement will remain in effect until June 2001
(unless earlier terminated), and will have to be approved annually thereafter by
a majority of the Trust's Trustees, including a majority of the Trustees who are
not "interested persons" of the Trust (as defined in the Investment Company Act
of 1940).

In connection with the appointment of Oechsle as Sub-Adviser to the Fund, the
"Sub-Advisers" Section on page 11 of the Class A Prospectus and on page 4 of the
Class D Prospectus is amended by inserting the following disclosure relating to
Oechsle:

OECHSLE INTERNATIONAL ADVISORS, LLC.

Oechsle International Advisors, LLC ("Oechsle"), acts as a Sub-Adviser for a
portion of the assets of the International Equity Fund. Oechsle is a limited
liability company that is registered as an investment adviser. Oechsle currently
has approximately $13 billion in assets under management. The principal business
address of Oechsle is One International Place, 23rd Floor, Boston, Massachusetts
02110.

S. Dewey Keesler, Jr., a founding Principal of Oechsle, and Kathleen Harris, a
Principal and Portfolio Manager/Research Analyst at Oechsle, serve as Portfolio
Managers of the portion of the Fund's assets managed by Oechsle. Prior to
founding Oechsle, Mr. Keesler was a Portfolio Manager at Putnam International
Advisors. He has over 17 years of investment experience. Prior to joining
Oechsle in 1995, Ms. Harris was a Portfolio Manager and Investment Director for
the State of Wisconsin Investment Board.

Listed below are the names and principal occupations of the principal executive
officer and each of the directors of Oechsle. The principal business address of
the principal executive officer and each of the directors, as it relates to
their position at Oechsle, is One International Place, 23rd Floor, Boston,
Massachusetts 02110.


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NAME                          TITLE
                           
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S. Dewey Keesler              CIO and Principal
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Stephen P. Langer             Principal/Director of Marketing
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Sean Roche                    COO and Principal
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Warren Walker                 Principal/Portfolio Manager


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The Adviser will pay Oechsle a fee based on a percentage of the average monthly
market value of the assets of the Fund assigned to Oechsle.
                           --------------------------

Each prospectus is hereby amended to reflect this change.

               PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE