<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): September 15, 2005

                          MERRILL LYNCH DEPOSITOR, INC.
                 (ON BEHALF OF PREFERREDPLUS TRUST SERIES BLC-1)
             (Exact name of registrant as specified in its charter)

          DELAWARE                   001-16605                 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.


<PAGE>

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 PreferredPLUS Trust
                 Certificates Series BLC-1 on September 15, 2005.

                         For information with respect to the underlying
                 securities held by PreferredPLUS Trust Series BLC-1, please
                 refer to Belo Corp.'s (Commission file number 001-08598)
                 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 issuer has filed electronically with
                 the SEC.

                          Although we have no reason to believe the
                 information concerning the underlying securities or the
                 underlying securities issuer contained in the underlying
                 securities issuer'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
                 (including, without limitation, no investigation as to its
                 financial condition or creditworthiness) or of the underlying
                 securities has been made. You should obtain and evaluate the
                 same information concerning the underlying securities issuer
                 as you would obtain and evaluate if you were investing
                 directly in the underlying securities or in other securities
                 issued by the underlying securities issuer. There can be no
                 assurance that events affecting the underlying securities or
                 the underlying securities issuer 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.

                     Not Applicable.

                 (b) Pro forma financial information.

                     Not Applicable.

                 (c) Exhibits.

                     99.1  Trustee's report in respect of the September
                           15, 2005 distribution to holders of the
                           PreferredPLUS Trust Certificates Series BLC-1.


                                   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:  September 23, 2005   By:      /s/ Stephan Kuppenheimer
                                              -------------------------------
                                              Name:  Stephan Kuppenheimer
                                              Title: President


                                  EXHIBIT INDEX


                     99.1  Trustee's report in respect of the September 15,
                           2005 distribution to holders of the PreferredPLUS
                           Trust Certificates Series BLC-1.
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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): September 15, 2005

                          MERRILL LYNCH DEPOSITOR, INC.
                 (ON BEHALF OF PREFERREDPLUS TRUST SERIES BLC-1)
             (Exact name of registrant as specified in its charter)

          DELAWARE                   001-16605                 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 PreferredPLUS Trust
                 Certificates Series BLC-1 on September 15, 2005.

                         For information with respect to the underlying
                 securities held by PreferredPLUS Trust Series BLC-1, please
                 refer to Belo Corp.'s (Commission file number 001-08598)
                 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 issuer has filed electronically with
                 the SEC.

                          Although we have no reason to believe the
                 information concerning the underlying securities or the
                 underlying securities issuer contained in the underlying
                 securities issuer'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
                 (including, without limitation, no investigation as to its
                 financial condition or creditworthiness) or of the underlying
                 securities has been made. You should obtain and evaluate the
                 same information concerning the underlying securities issuer
                 as you would obtain and evaluate if you were investing
                 directly in the underlying securities or in other securities
                 issued by the underlying securities issuer. There can be no
                 assurance that events affecting the underlying securities or
                 the underlying securities issuer 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.

                     Not Applicable.

                 (b) Pro forma financial information.

                     Not Applicable.

                 (c) Exhibits.

                     99.1  Trustee's report in respect of the September
                           15, 2005 distribution to holders of the
                           PreferredPLUS Trust Certificates Series BLC-1.

                                   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:  September 23, 2005   By:      /s/ Stephan Kuppenheimer
                                              -------------------------------
                                              Name:  Stephan Kuppenheimer
                                              Title: President

                                  EXHIBIT INDEX

                     99.1  Trustee's report in respect of the September 15,
                           2005 distribution to holders of the PreferredPLUS
                           Trust Certificates Series BLC-1.