<PAGE>
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JANUARY 26, 1999
FILE NO. 33-9504
FILE NO. 811-4878
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SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
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FORM N-1A
REGISTRATION STATEMENT UNDER THE
SECURITIES ACT OF 1933 / /
POST-EFFECTIVE AMENDMENT NO. 30 /X/
AND
REGISTRATION STATEMENT UNDER THE
INVESTMENT COMPANY ACT OF 1940 / /
AMENDMENT NO. 32 /X/
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SEI INSTITUTIONAL MANAGED TRUST
(Exact Name of Registrant as Specified in Charter)
C/O CT CORPORATION
2 Oliver Street
Boston, Massachusetts 02109
(Address of Principal Executive Offices) (Zip Code)
Registrant's Telephone Number, including Area Code: (800) 342-5734
EDWARD D. LOUGHLIN
c/o SEI Investments Company
Oaks, Pennsylvania 19456
(Name and Address of Agent for Service)
COPIES TO:
<TABLE>
<S> <C>
Richard W. Grant, Esq. John H. Grady, Jr., Esq.
Morgan Lewis & Bockius LLP Morgan Lewis & Bockius LLP
1701 Market Street 1701 Market Street
Philadelphia, Pennsylvania 19103 Philadelphia, Pennsylvania
19103
</TABLE>
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Title of Securities Being Registered . . . . . . . . . . . . . . Units of
Beneficial Interest
It is proposed that this filing become effective (check appropriate box)
<TABLE>
<C> <S>
/ / immediately upon filing pursuant to paragraph (b)
/X/ on January 28, 1999 pursuant to paragraph (b)
/ / 60 days after filing pursuant to paragraph (a)(1)
/ / on [date] pursuant to paragraph (a)(1)
/ / 75 days after filing pursuant to paragraph (a)(2)
/ / on [date] pursuant to paragraph (a)(2)
If appropriate, check the following box:
/X/ This post-effective Amendment designaties a new effective date for
a previously filed Post-Effective Amendment.
</TABLE>
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<PAGE>
The Prospectuses, Statement of Additional Information, and Part C for the SEI
Institutional Managed Trust, included as part of Post-Effective Amendment No. 29
to the Registrant's Registration Statement on Form N-1A (File No. 33-9504),
filed with the Securities and Exchange Commission on November 25, 1998 pursuant
to Rule 485(a) of the Securities Act of 1933, are hereby incorporated by
reference as if set forth fully herein.
<PAGE>
SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, as amended, and the
Investment Company Act of 1940, as amended, the Registrant certifies that it
meets all of the requirements for effectiveness of this Registration Statement
pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused
this Post-Effective Amendment No. 30 to Registration Statement No. 33-9504 to be
signed on its behalf by the undersigned, thereunto duly authorized, in the City
of Oaks, Commonwealth of Pennsylvania on the 20th day of January, 1999.
SEI INSTITUTIONAL MANAGED TRUST
By: /s/ Edward D. Loughlin
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Edward D. Loughlin
President & Chief Executive Officer
Pursuant to the requirements of the Securities Act of 1933, this Amendment
to the Registration Statement has been signed below by the following persons in
the capacity on the date(s) indicated.
* Trustee January 20, 1999
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William M. Doran
* Trustee January 20, 1999
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F. Wendell Gooch
* Trustee January 20, 1999
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George J. Sullivan, Jr.
* Trustee January 20, 1999
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James M. Storey
* Trustee January 20, 1999
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Robert A. Nesher
/s/ Edward D. Loughlin President & Chief January 20, 1999
- --------------------------- Executive Officer
Edward D. Loughlin
/s/ Mark E. Nagle Controller & Chief January 20, 1999
- --------------------------- Financial Officer
Mark E. Nagle
*By: /s/ Edward D. Loughlin
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Edward D. Loughlin
Attorney-in-Fact
