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SUPPLEMENT TO THE PROSPECTUS OF
DEAN WITTER SELECT DIMENSIONS INVESTMENT SERIES
DATED OCTOBER 25, 1994
The sentences pertaining to the North American Government Securities
Portfolio and the Emerging Markets Portfolio in the subsection entitled
"Portfolio Management" under the subsection entitled "General Portfolio
Techniques" in the section of the Prospectus entitled "INVESTMENT OBJECTIVES AND
POLICIES" are hereby replaced by the following:
Philip A. Barach, James M. Goldberg, Frederick H. Horton,
Jeffrey E. Gundlach and Douglas R. Metcalf, Managing Directors
of the Sub-Adviser, are the primary portfolio managers of the
NORTH AMERICAN GOVERNMENT SECURITIES PORTFOLIO and, with the
exception of Mr. Horton, have been so since the Fund's
inception. Mr. Horton has been a primary portfolio manager of
the Portfolio since December, 1994. Messrs. Barach, Gundlach and
Goldberg have been portfolio managers with affiliates of The TCW
Group, Inc. for over five years. Mr. Metcalf has been a
portfolio manager with affiliates of The TCW Group, Inc. since
March, 1990, prior to which time he was Managing Director of
First Interstate Bank Ltd. Mr. Horton has been a portfolio
manager with affiliates of The TCW Group, Inc. since October,
1993. From June, 1991-September, 1993, he was Senior Portfolio
Manager for Dewey Square Investors, prior to which time he was
Senior Portfolio Manager for the Putnam Companies.
Shaun C.K. Chan, Managing Director of TCW Asia Ltd., Robert
J.M. Rawe, President, Managing Director, Chief Executive Officer
and Director of TCW London International, Limited, Michael P.
Reilly, Senior Vice President of the Sub-Adviser, and Paul C.
Wargnier, Managing Director of the Sub-Adviser, are the primary
portfolio managers of the EMERGING MARKETS PORTFOLIO and, with
the exception of Mr. Reilly, have been so since the Fund's
inception. Mr. Reilly has been a primary portfolio manager of
the Portfolio since December, 1994. Mr. Chan has been a
portfolio manager with affiliates of The TCW Group, Inc. since
1993, prior to which time he was Director of Wardley Investment
Services (Hong Kong) Ltd. Mr. Rawe has been a portfolio manager
with TCW London International, Limited since August, 1993, prior
to which time he was President and Chief Executive Officer of
Dillon, Read International Asset Management Co. Mr. Reilly has
been a portfolio manager with affiliates of The TCW Group, Inc.
since June, 1992, prior to which time he was Vice President of
Security Pacific Bank. Mr. Wargnier has been a portfolio manager
with affiliates of The TCW Group, Inc. since June, 1990, prior
to which time he was Vice President and Director of Research for
D.A. Campbell Co., Inc., an institutional brokerage firm.
December 22, 1994
40460A
