AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 2, 2003
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                               ------------------

                                  SCHEDULE TO
                         ISSUER TENDER OFFER STATEMENT
                   UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE
                        SECURITIES EXCHANGE ACT OF 1934
                               (AMENDMENT NO. 1)
                      VAN KAMPEN SENIOR FLOATING RATE FUND
                                (NAME OF ISSUER)

                      VAN KAMPEN SENIOR FLOATING RATE FUND
                      (NAME OF PERSON(S) FILING STATEMENT)

        Common Shares of Beneficial Interest, Par Value $0.01 per Share
                         (Title of Class of Securities)

                                   920960-101
                     (CUSIP Number of Class of Securities)

                              A. Thomas Smith III
                          Vice President and Secretary
                          Van Kampen Investments Inc.
                           1221 Avenue of the Americas
                               New York, NY 10020
                                 (212) 762-5260
      (Name, Address and Telephone Number of Person Authorized to Receive
      Notices and Communications on Behalf of Person(s) Filing Statement)

                                   Copies to:
                             Wayne W. Whalen, Esq.
                              Thomas A. Hale, Esq.
                Skadden, Arps, Slate, Meagher & Flom (Illinois)
                              333 W. Wacker Drive
                            Chicago, Illinois 60606
                                 (312) 407-0700

                           CALCULATION OF FILING FEE
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- --------------------------------------------------------------------------------

Transaction Valuation $87,434,962(a)     Amount of Filing Fees: $7,073.49(b)
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(a)  Calculated as the aggregate maximum purchase price to be paid for
     11,993,822 shares in the offer.

(b)  Calculated as 0.00809% of the Transaction Valuation, previously paid.

 [X]   Check box if any part of the fee is offset as provided by Rule 0-11(a)(2)
       and identify the filing with which the offsetting fee was previously
       paid. Identify the previous filing by registration statement number, or
       the Form or Schedule and the date of its filing.

     Amount Previously Paid:  $7,073.49

     Form or Registration No.:  Schedule TO

     Filing Party:  Van Kampen Senior Floating Rate Fund

     Date Filed:  April 18, 2003

 [ ]   Check the box if the filing relates solely to preliminary communications
       made before the commencement of a tender offer.

 Check the appropriate boxes below to designate any transactions to which the
statement relates:

      [ ]   third-party tender offer subject to Rule 14d-1.

      [X]   issuer tender offer subject to Rule 13e-4.

      [ ]   going-private transaction subject to Rule 13e-3.

      [ ]   amendment to Schedule 13D under Rule 13d-2.

 [X]   Check the following box if the filing is a final amendment reporting the
       results of the tender offer.
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------

     This Amendment No. 1 to the Issuer's Tender Offer Statement on Schedule TO
filed with the Securities and Exchange Commission on April 18, 2003, by Van
Kampen Senior Floating Rate Fund (the "Fund"), with respect to the tender offer
to purchase up to 11,993,822 of the Fund's outstanding common shares of
beneficial interest, par value $0.01 per share, amends such statement on
Schedule TO to add the following supplemental information: the number of common
shares of beneficial interest of the Fund validly tendered through the
expiration date and not withdrawn was 3,350,200. All 3,350,200 such shares were
purchased in their entirety at the price of $7.43 per share, the net asset value
at the time the offer expired. Payment for the shares was mailed prior to the
date hereof. The Schedule TO is hereby terminated.

Item 9. Material to Be Filed as Exhibits.

     The following materials are hereby filed as additional Exhibits to the
Schedule TO:

     (a) (6) -- Text of Completion Press Release dated June 2, 2003


                                   SIGNATURE

     After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

                                          VAN KAMPEN SENIOR FLOATING RATE FUND

Dated: June 2, 2003                       /s/ A. Thomas Smith III
                                          ------------------------------------
                                          A. Thomas Smith III,
                                          Vice President and Secretary




                                 EXHIBIT INDEX

<Table>
<Caption>
      EXHIBIT                               DESCRIPTION
      -------                               -----------
                
       (a)(1)(i)   Advertisement printed in The Wall Street Journal.*
            (ii)   Offer to Purchase (including Financial Statements).*
          (a)(2)   Form of Letter of Transmittal (including Guidelines for
                   Certification of Taxpayer Identification Number).*
       (a)(3)(i)   Form of Letter to Brokers, Dealers, Commercial Banks, Trust
                   Companies and Other Nominees.*
            (ii)   Form of Letter to Clients of Brokers, Dealers, Commercial
                   Banks, Trust Companies and Other Nominees.*
           (iii)   Form of Letter to Selling Group Members.*
            (iv)   Form of Operations Notice.*
          (a)(4)   Form of Letter to Shareholders who have requested Offer to
                   Purchase.*
          (a)(5)   Text of Press Release dated April 18, 2003.*
          (a)(6)   Text of completion Press Release dated June 2, 2003.+
          (b)(1)   Fifth Amendment and Restatement of Credit Agreement between
                   Van Kampen Prime Rate Income Trust, Van Kampen Senior
                   Floating Rate Fund, Various Financial Institutions and Bank
                   of American, N.A., as agent, dated as of November 8, 2002.**
          (d)(1)   Investment Advisory Agreement between Van Kampen Senior
                   Floating Rate Fund and Van Kampen Investment Advisory Corp.,
                   dated as of December 19, 1997.***
          (d)(2)   Administration Agreement between Van Kampen Senior Floating
                   Rate Fund and Van Kampen Investments Inc., dated as of
                   December 19, 1997.***
          (d)(3)   Offering Agreement between Van Kampen Senior Floating Rate
                   Fund and Van Kampen Funds Inc., dated as of December 19,
                   1997.***
          (d)(4)   Service Plan of Van Kampen Senior Floating Rate Fund.***
         (g)-(h)   Not applicable.
</Table>

+ Filed herewith

  * Previously filed in the Fund's Schedule TO filed with the Securities and
    Exchange Commission on April 18, 2003.
 ** Previously filed in the Fund's Form N-2 filed with the Securities and
    Exchange Commission on November 27, 2002.
*** Previously filed in the Fund's Schedule TO filed with the Securities and
    Exchange Commission on April 19, 2002.


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