<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): June 1, 2006

                          MERRILL LYNCH DEPOSITOR, INC.
       (ON BEHALF OF PREFERREDPLUS 7.30% TRUST CERTIFICATES SERIES BLS-1)
             (Exact name of registrant as specified in its charter)

           DELAWARE             001-16471                    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

Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2.):

[  ]  Written communications pursuant to Rule 425 under the Securities Act (17
      CFR 230.425)

[  ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
      240.14a-12)

[  ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
      Exchange Act (17 CFR 240.14d-2(b))

[  ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
      Exchange Act (17 CFR 240.13e-4(c))


<PAGE>

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.   ASSET-BACKED SECURITIES

             Not applicable.

SECTION 7.   REGULATION FD

             Not applicable.

SECTION 8.   OTHER EVENTS

         ITEM 8.01    OTHER EVENTS

               99.1   Distribution to holders of the PreferredPLUS 7.30% Trust
                      Certificates Series BLS-1 on June 1, 2006.

                            For information with respect to the underlying
                      securities held by PreferredPLUS Trust Series BLS-1,
                      please refer to BellSouth Corporation's (Commission file
                      number 001-08607) 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 guarantor has filed
                      electronically with the SEC.

<PAGE>

                            Although we have no reason to believe the
                      information concerning the underlying securities, the
                      guarantee, the underlying securities issuer or 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 or the underlying securities
                      guarantor (including, without limitation, no investigation
                      as to their respective financial condition or
                      creditworthiness) or of the underlying securities or the
                      guarantee 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 you were investing 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, the guarantee,
                      the underlying securities issuer or 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.

                      Not Applicable.

               (b)    Pro forma financial information.

                      Not Applicable.

               (c)    Shell company transactions.

                      Not Applicable.

               (d)    Exhibits.

                      99.1   Trustee's report in respect of the June 1, 2006
                             distribution to holders of the PreferredPLUS 7.30%
                             Trust Certificates Series BLS-1.


<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: June 20, 2006           By:  /s/ Zvi Gillon
                                    ---------------------------------------
                                   Name:  Zvi Gillon
                                   Title: Vice President

<PAGE>

                              EXHIBIT INDEX


99.1     Trustee's report in respect of the June 1, 2006 distribution to holders
         of the PreferredPLUS 7.30% Trust Certificates Series BLS-1.
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{"company-data": {"conformed-name": "MERRILL LYNCH DEPOSITOR INC PREFERREDPLUS TRUST SERIES BLS-1", "cik": "0001139349", "assigned-sic": "6189", "irs-number": "133891329", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-16471", "film-number": "06915013"}, "business-address": {"street1": "WORLD FINANCIAL CENTER", "city": "NEW YORK", "state": "NY", "zip": "10281", "phone": "2124491000"}, "mail-address": {"street1": "WORLD FINANCIAL CTR", "street2": "NORTH TOWER", "city": "NEW YORK", "state": "NY", "zip": "10281"}}
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): June 1, 2006

                          MERRILL LYNCH DEPOSITOR, INC.
       (ON BEHALF OF PREFERREDPLUS 7.30% TRUST CERTIFICATES SERIES BLS-1)
             (Exact name of registrant as specified in its charter)

           DELAWARE             001-16471                    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

Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2.):

[  ]  Written communications pursuant to Rule 425 under the Securities Act (17
      CFR 230.425)

[  ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
      240.14a-12)

[  ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
      Exchange Act (17 CFR 240.14d-2(b))

[  ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
      Exchange Act (17 CFR 240.13e-4(c))
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.   ASSET-BACKED SECURITIES

             Not applicable.

SECTION 7.   REGULATION FD

             Not applicable.

SECTION 8.   OTHER EVENTS

         ITEM 8.01    OTHER EVENTS

               99.1   Distribution to holders of the PreferredPLUS 7.30% Trust
                      Certificates Series BLS-1 on June 1, 2006.

                            For information with respect to the underlying
                      securities held by PreferredPLUS Trust Series BLS-1,
                      please refer to BellSouth Corporation's (Commission file
                      number 001-08607) 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 guarantor has filed
                      electronically with the SEC.
Although we have no reason to believe the
                      information concerning the underlying securities, the
                      guarantee, the underlying securities issuer or 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 or the underlying securities
                      guarantor (including, without limitation, no investigation
                      as to their respective financial condition or
                      creditworthiness) or of the underlying securities or the
                      guarantee 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 you were investing 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, the guarantee,
                      the underlying securities issuer or 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.

                      Not Applicable.

               (b)    Pro forma financial information.

                      Not Applicable.

               (c)    Shell company transactions.

                      Not Applicable.

               (d)    Exhibits.

                      99.1   Trustee's report in respect of the June 1, 2006
                             distribution to holders of the PreferredPLUS 7.30%
                             Trust Certificates Series BLS-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: June 20, 2006           By:  /s/ Zvi Gillon
                                    ---------------------------------------
                                   Name:  Zvi Gillon
                                   Title: Vice President
EXHIBIT INDEX

99.1     Trustee's report in respect of the June 1, 2006 distribution to holders
         of the PreferredPLUS 7.30% Trust Certificates Series BLS-1.