PROSPECTUS Dated May 5, 1999 Pricing Supplement No. 77 to
PROSPECTUS SUPPLEMENT Registration Statement No. 333-75289
Dated May 6, 1999 May 10, 2000
Rule 424(b)(3)
Morgan Stanley Dean Witter & Co.
MEDIUM-TERM NOTES, SERIES C
Senior Floating Rate Notes
-----------------------
We will not redeem these Medium-Term Notes, Series C (Senior Floating Rate
Notes) prior to the maturity date. We describe the basic features of this type
of note in the section called "Description of Notes--Floating Rate Notes" in
the accompanying prospectus supplement, subject to and as modified by the
provisions described below.
Principal Amount: $100,000,000
Maturity Date: May 15, 2002
Interest Accrual
Date: May 15, 2000
Interest Payment
Dates: Each February 15,
May 15, August 15,
and November 15,
commencing August
15, 2000
Initial Interest Rate: To be determined on
the business day
immediately preceding
the Original Issue
Date
Base Rate: Federal Funds Rate
Index Maturity: One Day
Spread
(Plus or Minus): Plus 0.30% per annum
Index Currency: N/A
Interest Payment
Period: Quarterly
Specified Currency: U.S. Dollars
Issue Price: 100%
Settlement Date
(Original Issue Date): May 15, 2000
Initial Interest Reset
Date: May 16, 2000
Interest Reset Dates: Each business day
except the business
day immediately
preceding each
interest payment date
and except for any
business day within the
period beginning 10
calendar days prior to
maturity, redemption
or repayment
Interest Reset Period: Daily
Interest Determination
Dates: The business day
immediately preceding
each interest reset date
Reporting Service: Telerate (Page 120)
Book Entry Note or
Certificated Note: Book Entry Note
Senior Note or
Subordinated Note: Senior Note
Agent: Morgan Stanley & Co.
Incorporated
Calculation Agent: The Chase Manhattan
Bank
Minimum Denomination: $1,000
CUSIP: 61745EPX3
Terms not defined above have the meanings given to such terms in the
accompanying prospectus supplement.
MORGAN STANLEY DEAN WITTER
