<PAGE>
ST. CLAIR FUNDS, INC.
SUPPLEMENT DATED JANUARY 13, 1999
TO PROSPECTUS DATED MAY 1, 1998
MUNDER INSTITUTIONAL S&P 500 INDEX EQUITY FUND
MUNDER INSTITUTIONAL S&P MIDCAP INDEX EQUITY FUND
MUNDER INSTITUTIONAL S&P SMALLCAP INDEX EQUITY FUND
MUNDER INSTITUTIONAL S&P SHORT TERM TREASURY FUND
MUNDER INSTITUTIONAL S&P MONEY MARKET FUND
CHANGE OF ADDRESS
The "STRUCTURE AND MANAGEMENT OF THE FUND--Who Manages and Services the
Fund?--Transfer Agent" section in the Prospectus is hereby deleted in its
entirety and replaced with the following:
TRANSFER AGENT. First Data Investor Services Group, Inc. ("First Data"),
whose principal business address is 4400 Computer Drive, Westborough,
Massachusetts 01581-5120 serves as transfer agent and dividend disbursing agent.
First Data is a wholly-owned subsidiary of First Data Corporation.
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ST. CLAIR FUNDS, INC.
SUPPLEMENT DATED JANUARY 13, 1999
TO PROSPECTUS DATED MAY 1, 1998
LIQUIDITY PLUS MONEY MARKET FUND
CHANGE OF ADDRESS
The "STRUCTURE AND MANAGEMENT OF THE FUND--Who Manages and Services the
Fund?--Transfer Agent" section in the Prospectus is hereby deleted in its
entirety and replaced with the following:
TRANSFER AGENT. First Data Investor Services Group, Inc. ("First Data"),
whose principal business address is 4400 Computer Drive, Westborough,
Massachusetts 01581-5120 serves as transfer agent and dividend disbursing agent.
First Data is a wholly-owned subsidiary of First Data Corporation.
Shareholder inquiries may be directed to The Munder Funds, c/o First Data
Investor Services Group, P.O. Box 60428, King of Prussia, Pennsylvania
19406-0428.
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THIS SUPPLEMENT SUPERCEDES ALL PRIOR SUPPLEMENTS
ST. CLAIR FUNDS, INC.
SUPPLEMENT DATED JANUARY 13, 1999
TO STATEMENT OF ADDITIONAL INFORMATION DATED MAY 1, 1998
MUNDER INSTITUTIONAL S&P 500 INDEX EQUITY FUND
MUNDER INSTITUTIONAL S&P MIDCAP INDEX EQUITY FUND
MUNDER INSTITUTIONAL S&P SMALLCAP INDEX EQUITY FUND
MUNDER INSTITUTIONAL S&P SHORT TERM TREASURY FUND
MUNDER INSTITUTIONAL S&P MONEY MARKET FUND
INVESTMENT ADVISORY AGREEMENT
The second paragraph of the "INVESTMENT ADVISORY AND OTHER SERVICE
ARRANGEMENTS" section in the Statement of Additional Information is deleted in
its entirety and replaced with the following:
The Funds have entered into an Investment Advisory Agreement (the "Advisory
Agreement") with the Advisor on behalf of each Fund of the Company. The
Advisory Agreement has been approved by the Board of Directors and by the
shareholders of each Fund. Under the terms of the Advisory Agreement, the
Advisor furnishes continuing investment supervision to the Funds and is
responsible for the management of each Fund's portfolio. The responsibility for
making decisions to buy, sell or hold a particular security rests with the
Advisor, subject to review by the Company's Board of Directors.
<PAGE>
THIS SUPPLEMENT SUPERCEDES ALL PRIOR SUPPLEMENTS
ST. CLAIR FUNDS, INC.
SUPPLEMENT DATED JANUARY 13, 1999
TO STATEMENT OF ADDITIONAL INFORMATION DATED MAY 1, 1998
LIQUIDITY PLUS MONEY MARKET FUND
INVESTMENT ADVISORY AGREEMENT
The second paragraph of the "INVESTMENT ADVISORY AND OTHER SERVICE
ARRANGEMENTS" section in the Statement of Additional Information is deleted in
its entirety and replaced with the following:
The Fund has entered into an Investment Advisory Agreement (the
"Advisory Agreement") with the Advisor on behalf the of Fund of the Company.
The Advisory Agreement has been approved by the Board of Directors and by the
shareholders of the Fund. Under the terms of the Advisory Agreement, the
Advisor furnishes continuing investment supervision to the Fund and is
responsible for the management of the Fund's portfolio. The responsibility
for making decisions to buy, sell or hold a particular security rests with
the Advisor, subject to review by the Company's Board of Directors.
