<PAGE>


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

                                    FORM 8-K

                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                       The Securities Exchange Act of 1934

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

        Date of Report (Date of earliest event reported): August 15, 2005

                          MERRILL LYNCH DEPOSITOR, INC.
                     (ON BEHALF OF PPLUS TRUST SERIES GSC-3)
             (Exact name of registrant as specified in its charter)

        DELAWARE                   001-32364                    13-3891329
    (State or other              (Commission                (I. R. S. Employer
    jurisdiction  of              File Number)              Identification No.)
     incorporation)

 WORLD FINANCIAL CENTER,                                           10080
   NEW YORK, NEW YORK                                           (Zip Code)
  (Address of principal
   executive offices)
                           --------------------------

       Registrant's telephone number, including area code: (212) 449-1000

                      INFORMATION TO BE INCLUDED IN REPORT


SECTION 1.  REGISTRANT'S BUSINESS AND OPERATIONS

            Not applicable.

SECTION 2.  FINANCIAL INFORMATION

            Not applicable.

SECTION 3.  SECURITIES AND TRADING MARKETS

            Not applicable.

SECTION 4.  MATTERS RELATED TO ACCOUNTANTS AND FINANCIAL STATEMENTS

            Not applicable.

SECTION 5.  CORPORATE GOVERNANCE AND MANAGEMENT

            Not applicable.

SECTION 6.  [RESERVED]

SECTION 7.  REGULATION FD

            Not applicable.

SECTION 8.  OTHER EVENTS


<PAGE>

       ITEM 8.01  OTHER EVENTS

            99.1  Distribution to holders of the PPLUS Trust Certificates Series
                  GSC-3 on August 15, 2005.

                        For information with respect to the underlying
                  securities held by PPLUS Trust Series GSC-3, please refer to
                  The Goldman Sachs Group, Inc.'s (Commission file number
                  001-14965) periodic reports, including annual reports on Form
                  10-K, quarterly reports on Form 10-Q and current reports on
                  Form 8-K, and other information on file with the Securities
                  and Exchange Commission (the "SEC"). You can read and copy
                  these reports and other information at the public reference
                  facilities maintained by the SEC at Room 1580, 100 F Street,
                  NE, Washington, D.C. 20549. You may obtain copies of this
                  material for a fee by writing to the SEC's Public Reference
                  Section of the SEC at 100 F Street, NE, Washington, D.C.
                  20549. You may obtain information about the operation of the
                  Public Reference Room by calling the SEC at 1-800-SEC-0330.
                  You can also access some of this information electronically by
                  means of the SEC's website on the Internet at
                  http://www.sec.gov, which contains reports, proxy and
                  information statements and other information that the
                  underlying securities guarantor and underlying securities
                  issuer has filed electronically with the SEC.

                        Although we have no reason to believe the information
                  concerning the underlying securities and the junior
                  subordinated debentures or the underlying securities issuer
                  and the underlying securities guarantor contained in the
                  underlying securities guarantor's Exchange Act reports is not
                  reliable, neither the depositor nor the trustee participated
                  in the preparation of such documents or made any due diligence
                  inquiry with respect to the information provided therein. No
                  investigation with respect to the underlying securities issuer
                  and the underlying securities guarantor (including, without
                  limitation, no investigation as to their financial condition
                  or creditworthiness) or of the underlying securities and the
                  junior subordinated debentures has been made. You should
                  obtain and evaluate the same information concerning the
                  underlying securities issuer and the underlying securities
                  guarantor as you would obtain and evaluate if your investment
                  were directly in the underlying securities or in other
                  securities issued by the underlying securities issuer or the
                  underlying securities guarantor. There can be no assurance
                  that events affecting the underlying securities and the junior
                  subordinated debentures or the underlying securities issuer
                  and the underlying securities guarantor have not occurred or
                  have not yet been publicly disclosed which would affect the
                  accuracy or completeness of the publicly available documents
                  described above.


<PAGE>

SECTION 9.  FINANCIAL STATEMENTS AND EXHIBITS

           ITEM 9.01    FINANCIAL STATEMENTS AND EXHIBITS

                  (a)   Financial statements of business acquired.

                        None.

                  (b)   Pro forma financial information.

                        None.

                  (c)   Exhibits.

                        99.1  Trustee's report in respect of the August 15, 2005
                              distribution to holders of the PPLUS Trust
                              Certificates Series GSC-3.

<PAGE>


                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, hereunto duly authorized.


                                                MERRILL LYNCH DEPOSITOR, INC.

         Date: August 25, 2005              By: /s/ Stephan Kuppenheimer
                                                 -------------------------------
                                                Name: Stephan Kuppenheimer
                                                Title: President




<PAGE>



                                  EXHIBIT INDEX


      99.1  Trustee's report in respect of the August 15, 2005 distribution to
            holders of the PPLUS Trust Certificates Series GSC-3.
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SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549
                           --------------------------

                                    FORM 8-K

                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                       The Securities Exchange Act of 1934

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

        Date of Report (Date of earliest event reported): August 15, 2005

                          MERRILL LYNCH DEPOSITOR, INC.
                     (ON BEHALF OF PPLUS TRUST SERIES GSC-3)
             (Exact name of registrant as specified in its charter)

        DELAWARE                   001-32364                    13-3891329
    (State or other              (Commission                (I. R. S. Employer
    jurisdiction  of              File Number)              Identification No.)
     incorporation)

 WORLD FINANCIAL CENTER,                                           10080
   NEW YORK, NEW YORK                                           (Zip Code)
  (Address of principal
   executive offices)
                           --------------------------

       Registrant's telephone number, including area code: (212) 449-1000

                      INFORMATION TO BE INCLUDED IN REPORT

SECTION 1.  REGISTRANT'S BUSINESS AND OPERATIONS

            Not applicable.

SECTION 2.  FINANCIAL INFORMATION

            Not applicable.

SECTION 3.  SECURITIES AND TRADING MARKETS

            Not applicable.

SECTION 4.  MATTERS RELATED TO ACCOUNTANTS AND FINANCIAL STATEMENTS

            Not applicable.

SECTION 5.  CORPORATE GOVERNANCE AND MANAGEMENT

            Not applicable.

SECTION 6.  [RESERVED]

SECTION 7.  REGULATION FD

            Not applicable.

SECTION 8.  OTHER EVENTS
ITEM 8.01  OTHER EVENTS

            99.1  Distribution to holders of the PPLUS Trust Certificates Series
                  GSC-3 on August 15, 2005.

                        For information with respect to the underlying
                  securities held by PPLUS Trust Series GSC-3, please refer to
                  The Goldman Sachs Group, Inc.'s (Commission file number
                  001-14965) periodic reports, including annual reports on Form
                  10-K, quarterly reports on Form 10-Q and current reports on
                  Form 8-K, and other information on file with the Securities
                  and Exchange Commission (the "SEC"). You can read and copy
                  these reports and other information at the public reference
                  facilities maintained by the SEC at Room 1580, 100 F Street,
                  NE, Washington, D.C. 20549. You may obtain copies of this
                  material for a fee by writing to the SEC's Public Reference
                  Section of the SEC at 100 F Street, NE, Washington, D.C.
                  20549. You may obtain information about the operation of the
                  Public Reference Room by calling the SEC at 1-800-SEC-0330.
                  You can also access some of this information electronically by
                  means of the SEC's website on the Internet at
                  http://www.sec.gov, which contains reports, proxy and
                  information statements and other information that the
                  underlying securities guarantor and underlying securities
                  issuer has filed electronically with the SEC.

                        Although we have no reason to believe the information
                  concerning the underlying securities and the junior
                  subordinated debentures or the underlying securities issuer
                  and the underlying securities guarantor contained in the
                  underlying securities guarantor's Exchange Act reports is not
                  reliable, neither the depositor nor the trustee participated
                  in the preparation of such documents or made any due diligence
                  inquiry with respect to the information provided therein. No
                  investigation with respect to the underlying securities issuer
                  and the underlying securities guarantor (including, without
                  limitation, no investigation as to their financial condition
                  or creditworthiness) or of the underlying securities and the
                  junior subordinated debentures has been made. You should
                  obtain and evaluate the same information concerning the
                  underlying securities issuer and the underlying securities
                  guarantor as you would obtain and evaluate if your investment
                  were directly in the underlying securities or in other
                  securities issued by the underlying securities issuer or the
                  underlying securities guarantor. There can be no assurance
                  that events affecting the underlying securities and the junior
                  subordinated debentures or the underlying securities issuer
                  and the underlying securities guarantor have not occurred or
                  have not yet been publicly disclosed which would affect the
                  accuracy or completeness of the publicly available documents
                  described above.
SECTION 9.  FINANCIAL STATEMENTS AND EXHIBITS

           ITEM 9.01    FINANCIAL STATEMENTS AND EXHIBITS

                  (a)   Financial statements of business acquired.

                        None.

                  (b)   Pro forma financial information.

                        None.

                  (c)   Exhibits.

                        99.1  Trustee's report in respect of the August 15, 2005
                              distribution to holders of the PPLUS Trust
                              Certificates Series GSC-3.
SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, hereunto duly authorized.

                                                MERRILL LYNCH DEPOSITOR, INC.

         Date: August 25, 2005              By: /s/ Stephan Kuppenheimer
                                                 -------------------------------
                                                Name: Stephan Kuppenheimer
                                                Title: President
EXHIBIT INDEX

      99.1  Trustee's report in respect of the August 15, 2005 distribution to
            holders of the PPLUS Trust Certificates Series GSC-3.