<PAGE>
Filed Pursuant to Rule 497(e)
Registration File No.: 2-66269
SUPPLEMENT TO THE PROSPECTUS OF
MORGAN STANLEY DEAN WITTER
AMERICAN OPPORTUNITIES FUND
DATED APRIL 26, 1999
The disclosure in the section entitled "ADDITIONAL INVESTMENT STRATEGY
INFORMATION" is amended to include the following:
Options and Futures. The Fund may purchase and sell stock index futures
contracts and may purchase put options on stock indexes and stock index
futures. Stock index futures and options on stock indexes and stock index
futures may be used to facilitate trading, to increase or decrease the
Fund's market exposure, to seek higher investment returns, or to seek to
protect against a decline in the value of the Fund's securities or an
increase in prices of securities that may be purchased.
The disclosure in the section entitled "ADDITIONAL RISK INFORMATION" is
amended to include the following:
Options and Futures. If the Fund invests in stock index futures or options
on stock indexes or stock index futures, its participation in these
markets would subject the Fund to certain risks. If the Investment
Manager's predictions of movements in the direction of the stock index are
inaccurate, the adverse consequences to the Fund (e.g., a reduction in the
Fund's net asset value or a reduction in the amount of income available
for distribution) may leave the Fund in a worse position than if these
strategies were not used. Other risks inherent in the use of stock index
futures and options on stock indexes and stock index futures include, for
example, the possible imperfect correlation between the price of futures
contracts and movements in the prices of the securities, and the possible
absence of a liquid secondary market for any particular instrument.
July 29, 1999
