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                                                             EXHIBIT (a)(3)(iii)

                            [VAN KAMPEN LETTERHEAD]

October 20, 2000

RE: VAN KAMPEN SENIOR FLOATING RATE FUND
     Commencement of Tender Offer

To Our Dealer Friends:

     As you may be aware, it is the policy of the Board of Trustees of Van
Kampen Senior Floating Rate Fund (the "Trust") to consider on a quarterly basis
whether to make a tender offer for common shares of the Trust. We are pleased to
announce that the Board has authorized the Trust's eleventh quarterly tender
offer commencing today, October 20, 2000, for the purpose of attempting to
provide liquidity to its shareholders. The commencement of the tender offer was
announced in the Wall Street Journal today.

     The Trust is offering to purchase up to 43,805,306 of its common shares at
a price equal to the net asset value per common share of the Trust determined as
of 5:00 P.M. Eastern Time on the expiration date of the offer. The offer is
scheduled to terminate as of 12:00 Midnight Eastern Time on November 17, 2000,
the expiration date of the offer (unless extended). An "Early Withdrawal Charge"
will be imposed on most common shares accepted for payment that have been held
for less than one year.

     Terms and conditions of the tender offer are contained in the Trust's Offer
to Purchase dated October 20, 2000, and the related Letter of Transmittal,
copies of which are available to you upon request.

     Should you have any questions regarding the tender offer, please contact
Van Kampen's Investor Services Department at 1-800-421-5666.

Sincerely,

VAN KAMPEN FUNDS INC.

                                                                 11 SFR003-10/00