<PAGE>
SEI INSTITUTIONAL INVESTMENTS TRUST
INTERNATIONAL EQUITY FUND
SUPPLEMENT DATED JANUARY 12, 2000 TO THE
PROSPECTUS DATED SEPTEMBER 30, 1999
THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT CONTAINED IN
THE PROSPECTUS, AND SHOULD BE READ IN CONJUNCTION WITH SUCH PROSPECTUS.
The Board of Trustees of SEI Institutional Investments Trust (the "Trust"),
including all of the Trustees who are not "interested persons" of the Trust,
have appointed BlackRock International, Ltd. ("BlackRock International"), as a
Sub-Adviser to the Trust's International Equity Fund (the "Fund"). In connection
with the departure of Albert Morrillo from Scottish Widows Investment Management
("SWIM") and BlackRock International's hiring of Mr. Morrillo, BlackRock
International replaced SWIM as a Sub-Adviser to the Fund. SWIM's contract will
expire March 23, 2000, and not will be renewed. SWIM is not currently managing
any Fund assets.
BlackRock International was approved as a Sub-Adviser at the Quarterly Meeting
of the Board of Trustees held on December 13-14, 1999, and its appointment does
not require Shareholder approval. This procedure for adding or replacing Sub-
Advisers was approved by the Trust's sole initial shareholder on June 14, 1996,
and was authorized by an exemptive order issued to the Trust by the Securities
and Exchange Commission on April 29, 1996.
In evaluating BlackRock International, the Trustees received written and oral
information from SEI Investments Management Corporation ("SIMC") and BlackRock
International. SIMC recommended the selection of BlackRock International and
reviewed the considerations and the search process that led to its
recommendation. The Trustees also met with representatives of BlackRock
International and considered information about portfolio managers, investment
philosophy, strategies and process, as well as its performance track record,
among other factors. In appointing BlackRock International, the Trustees
carefully evaluated: (1) the nature and quality of the services expected to be
rendered to the Fund by BlackRock International; (2) the distinct investment
process of BlackRock International; (3) the history, reputation, qualification
and background of BlackRock International'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 BlackRock International,
including any benefits to be received by BlackRock International or its
affiliates in connection with soft dollar arrangements.
Under the Investment Sub-Advisory Agreement ("Sub-Advisory Agreement") between
SIMC (the "Adviser") and BlackRock International relating to the Fund, BlackRock
International makes investment decisions for the assets of the Fund allocated to
BlackRock International by SIMC, and continuously reviews, supervises and
administers the Fund's investment program with respect to these assets.
BlackRock International 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 and the standard of care and
termination provisions of the Agreement are similar to the other agreements. The
Sub-Advisory Agreement will remain in effect until December 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 BlackRock International as Sub-Adviser to
the Fund, the "Sub-Advisers" Section on page 25 of the Prospectus is amended by
inserting the following disclosure relating to BlackRock International under the
heading "International Equity Fund":
BLACKROCK INTERNATIONAL, LTD.
BlackRock International, Ltd. ("BlackRock International"), acts as a Sub-Adviser
for a portion of the assets of the International Equity Fund. BlackRock
International is one of the non-U.S. investment advisory subsidiaries of
BlackRock, Inc. BlackRock, Inc., through its various investment advisory
subsidiaries, currently has approximately $159 billion in assets under
management. The principal business address of BlackRock International is
7 Castle Steet, Edinburgh, EH2 3AM Scotland, U.K.
Albert B. Morillo, Managing Director and Senior Portfolio Manager, heads an
investment committee at BlackRock International that serves as portfolio manager
of the portion of the Fund's assets managed by BlackRock International. Prior to
joining BlackRock International in January 2000, Mr. Morillo was the head of the
European Team at Scottish Widows Investment Management.
<PAGE>
Listed below are the names and principal occupations of the principal executive
officer and each of the directors of BlackRock International. The principal
business address of the principal executive officer and each of the directors,
as it relates to their position at BlackRock International, is 7 Castle Steet,
Edinburgh, EH2 3AM Scotland, U.K.
<TABLE>
<S> <C>
NAME TITLE
Laurence D. Fink Chairman and Chief Executive Officer
Robert S. Kapito Vice Chairman and Director
Ralph L. Schlosstein President Director
</TABLE>
The Adviser will pay BlackRock International a fee based on a percentage of the
average monthly market value of the assets of the Fund assigned to BlackRock
International.
--------------------------
The prospectus is hereby amended to reflect these changes.
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE
