As filed with the Securities and Exchange Commission on March 21, 2005

                                             Securities Act File No. 333-39837
                                      Investment Company Act File No. 811-5870

==============================================================================

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549

                           -------------------------


                                  SCHEDULE TO
                         ISSUER TENDER OFFER STATEMENT
                     (PURSUANT TO SECTION 13(e)(1) OF THE
                       SECURITIES EXCHANGE ACT OF 1934)
                               (Amendment No. 1)

                 Merrill Lynch Senior Floating Rate Fund, Inc.
                               (Name of Issuer)

                 Merrill Lynch Senior Floating Rate Fund, Inc.
                     (Names of Person(s) Filing Statement)

               Shares of Common Stock, Par Value $.10 per share
                        (Title of Class of Securities)

                                  59019R 10 5
                     (CUSIP Number of Class of Securities)

                              Robert C. Doll, Jr.
                 Merrill Lynch Senior Floating Rate Fund, Inc.
                            800 Scudders Mill Road
                         Plainsboro, New Jersey 08536
                                (609) 282-2800
          (Name, Address and Telephone Number of Person Authorized to
  Receive Notices and Communications on Behalf of Person(s) Filing Statement)

                                  Copies to:




                                                     
Thomas R. Smith, Jr., Esq.                              Andrew J. Donohue, Esq.
Sidley Austin Brown & Wood LLP                          Merrill Lynch Investment Managers, L.P.
787 Seventh Avenue                                      P.O. Box 9011
New York, New York 10019                                Princeton, New Jersey 08543-9011





                               February 14, 2005
                      (Date Tender Offer First Published,
                      Sent or Given to Security Holders)





     This Amendment No. 1 to the Issuer Tender Offer Statement on Schedule TO
of Merrill Lynch Senior Floating Rate Fund, Inc. (the "Fund") relating to an
offer to purchase (the "Offer") up to 20,000,000 of the Fund's shares of
common stock, par value $0.10 per share (the "Shares") and originally filed
with the Securities and Exchange Commission on February 14, 2005, constitutes
the final amendment pursuant to Rule 13e-4(c)(3) under the Securities Exchange
Act of 1934.

     The Offer terminated at 4:00 p.m., Eastern time, on March 15, 2005 (the
"Expiration Date"). Pursuant to the Offer, 3,742,807.944 Shares were tendered,
all of which were accepted by the Fund for repurchase at a net asset value of
$9.03 per share, as determined as of the close of the New York Stock Exchange
on the Expiration Date, for an aggregate purchase price of $33,797,555.73.





                                   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.


                               MERRILL LYNCH SENIOR FLOATING RATE FUND, INC.



March 21, 2005                 By: /s/ Donald C. Burke
                                   -----------------------------------
                               (Donald C. Burke, Vice President and Treasurer)





                                   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.

                               MASTER SENIOR FLOATING RATE TRUST



March 21, 2005                 By: /s/ Donald C. Burke
                                   -----------------------------------
                               (Donald C. Burke, Vice President and Treasurer)