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Filed Pursuant to Rule 497(e)
Registration File No.: 33-54047
811-7185
SUPPLEMENT TO THE PROSPECTUS OF
MORGAN STANLEY DEAN WITTER SELECT DIMENSIONS INVESTMENT SERIES,
CLASS X SHARES
DATED MAY 1, 2000
The third sentence of the section of the Prospectus titled "PRINCIPAL
INVESTMENT STRATEGIES" pertaining to the Developing Growth Portfolio of the Fund
is hereby replaced by the following:
The Investment Manager focuses its securities selection upon a diversified
group of emerging growth companies that it believes have prospects of
achieving significant profit gains.
In addition, the paragraphs pertaining to the Diversified Income Portfolio
and the Developing Growth Portfolio of the Fund in the section of the Prospectus
titled "PORTFOLIO MANAGEMENT" are hereby replaced by the following:
DIVERSIFIED INCOME PORTFOLIO -- W. David Armstrong, Steven F. Esser and
Paul F. O'Brien have been the primary portfolio managers of the Portfolio
since January 2001. Mr. Armstrong is a Managing Director of the Investment
Manager as well as a Managing Director and member of the Interest Rate
Research Team of Miller Anderson & Sherrerd, LLP ("MAS"), an affiliate of
the Investment Manager (since 1998), and prior thereto was a Senior Vice
President of Lehman Brothers (1995-1997). Mr. Esser is a Managing Director
of the Investment Manager as well as a Managing Director of MAS. Mr. Esser
has been managing portfolios for MAS and investment advisory affiliates of
MAS for over five years. Mr. O'Brien is a Principal of the Investment
Manager as well as a Principal and member of the Interest Rate Research
Team of MAS (since 1996) and prior thereto was an Economist at J.P. Morgan,
London.
DEVELOPING GROWTH PORTFOLIO -- Arden C. Armstrong and John Roscoe are the
primary portfolio managers of the Portfolio. Ms. Armstrong, a Managing
Director of the Investment Manager as well as a Managing Director of MAS,
has been a primary portfolio manager of the Portfolio since January 2001.
Ms. Armstrong has been managing portfolios for MAS and investment advisory
affiliates of MAS for over five years. Mr. Roscoe, a Vice President of the
Investment Manager, has been a primary portfolio manager of the Portfolio
since April 2000. Mr. Roscoe has been a portfolio manager with the
Investment Manager since December 1997, prior to which time he was an
equity analyst at Rockefeller and Company, Inc.
January 8, 2001
