SEC 1746
(11-02)

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UNITED STATES

OMB
APPROVAL

SECURITIES AND EXCHANGE
COMMISSION

OMB Number:
3235-0145

Washington, D.C. 20549

Expires:
December 31, 2005

SCHEDULE 13D

Estimated average burden hours per response. . 11

Under the Securities Exchange Act of 1934
(Amendment No. 4)*

Item 1.

Security and Issuer

This Amendment No. 4 (the “Amendment”) amends the Schedule 13D filed on March 14, 1984 by Alfred P. West, Jr., as amended by Amendment No. 1 filed on December 30, 1991, Amendment No. 2 filed on April 9, 1998 and Amendment No. 3 filed on May 15, 1998, with respect to shares of common stock, $0.01 par value (the “Common Stock”) of SEI Investments Company (the “Issuer”), as follows:

Item 4.

Purpose of Transaction

Other than as described in Item 6 below, Mr. West has no present plan or proposal that would result in or relate to any of the transactions in subparagraphs (a) through (j) of Item 4 of Schedule 13D.

Item 5.

Interest in Securities of the Issuer

Mr. West beneficially owns 24,704,031 shares of Common Stock as of March 1, 2003, which represents approximately 23.38% of the Issuer’s Common Stock based on 105,554,135 shares of Common Stock outstanding as of February 28, 2003, as reported by the Issuer in its Annual Report on Form 10-K for the fiscal year ended December 31, 2002.  This amount includes (i) 11,878,778 shares held by Mr. West directly; (ii) 24,000 shares held by Mr. West’s wife; (iii) 4,939,724 shares held in trusts for the benefit of Mr. West’s children (the “Children’s Trusts”), of which  trusts Mr. West’s wife is a trustee or co-trustee; (iv) 48,000 shares held in a trust for the benefit of William M. Doran’s children, of which trust Mr. West is a trustee; and  (v) 96,000 shares that may be acquired upon exercise of stock options exercisable within 60 days of March 1, 2003 held in the same trust for the benefit of William M. Doran’s children, of which Mr. West is a trustee.  Mr. West disclaims beneficial ownership of the shares held in these trusts.  This amount also includes (i) 4,537,500 shares held by APWest Associates, L.P., a Delaware limited partnership of which Mr. West is the sole general partner; (ii) 2,773,883 shares held in the Alfred P. West 1998 Grantor Retained Annuity Trust V, of which Mr. West is the sole trustee; and (iii) 406,146 shares held by the West Family Foundation, of which Mr. West is a director and officer and, accordingly, shares voting and investment power.

Item 6.

Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

On September 16, 2002, Mr. West and his wife entered into a collateral agreement, as amended on November 25, 2002 (the “West Collateral Agreement”), with JP Morgan Chase Bank and its subsidiaries and affiliates (“JP Morgan”), pursuant to which, among other things, and subject to certain limitations, Mr. West and his wife pledged to JP Morgan approximately 11,878,778 shares of the Common Stock of the Issuer held directly or indirectly by Mr. West, subject to adjustment, as security for certain loans, letters of credit or other financial accommodations extended by JP Morgan to Mr. West and his wife.

On September 16, 2002, the West Family Foundation entered into a collateral agreement, as amended on November 25, 2002 (the “Foundation Collateral Agreement”), with JP Morgan, pursuant to which, among other things, and subject to certain limitations, the West Family Foundation pledged to JP Morgan approximately 109,200 shares of the Common Stock of the Issuer held by the West Family Foundation, subject to adjustment, as security for certain loans, letters of credit or other financial accommodations extended by JP Morgan to the West Family Foundation.

On September 16, 2002, certain of the Children’s Trusts entered into collateral agreements, as amended on November 25, 2002 (each a “Trust Collateral Agreement” and collectively, the “Trust Collateral Agreements”) with JP Morgan, pursuant to which, among other things, and subject to certain

limitations, these trusts pledged to JP Morgan approximately 2,806,030 shares of the Common Stock of the Issuer, subject to adjustment, as security for certain loans, letters of credit or other financial accommodations extended by JP Morgan to these trusts.

The West Collateral Agreement, the Foundation Collateral Agreement and the Trust Collateral Agreements are referred to herein as the Collateral Agreements.  These Collateral Agreements provide that, subject to certain limitations, upon specified events of default, JP Morgan will obtain both voting and dispositive power with respect to the shares of Common Stock covered by the Collateral Agreements.

The descriptions of each of the Collateral Agreements are qualified by reference to each of the Collateral Agreements, copies of which are filed as exhibits to this Amendment.  Please read these exhibits for further information regarding the Collateral Agreements.

Item 7.

Material to Be Filed as Exhibits

99.1

Collateral Agreement, dated as of September 16, 2002, as amended, by and among JP Morgan Chase Bank, Alfred P. West, Jr. and Loralee S. West

99.2

Collateral Agreement, dated as of September 16, 2002, as amended, by and between JP Morgan Chase Bank and the West Family Foundation

99.3

Collateral Agreement, dated as of September 16, 2002, as amended, by and among JP Morgan Chase Bank and Loralee S. West and William M. Doran as Trustees under the Agreement of Trust dated December 22, 1980, established by Alfred P. West, Jr. for the benefit of Angela Paige West

99.4

Collateral Agreement, dated as of September 16, 2002, as amended, by and among JP Morgan Chase Bank and Loralee S. West and William M. Doran as Trustees under the Agreement of Trust dated December 22, 1980, established by Alfred P. West, Jr. for the benefit of Andrew Palmer West

Date

/s/ Alfred P. West, Jr.

Signature

Alfred P. West, Jr.

Name/Title