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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

                                   FORM 10-K

                                 ANNUAL REPORT

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

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

For the fiscal year ended:                               Commission file number:
    December 31, 2004                                          001-16507

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

               DELAWARE                                 13-3891329
            (State or other                         (I. R. S. Employer
            jurisdiction of                         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

Securities registered pursuant to Section 12(b) of the Act:

PreferredPLUS Trust Certificates Series ATT-1, listed on The New York Stock
Exchange

Securities registered pursuant to Section 12(g) of the Act:

Not Applicable.

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

                                 Yes [X] No [ ]

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this form 10-K or any amendment to this
form 10-K.

Indicate by check mark whether the registrant is an accelerated filer (as
defined in Rule 12b-2 of the Act).

                                 Yes [ ] No [X]

State the aggregate market value of the voting and non-voting common equity held
by non-affiliates of the registrant. The aggregate market value shall be
computed by reference to the price at which the common equity was sold, or the
average bid and asked prices of such common equity, as of the last business day
of the registrant's most recently completed second fiscal quarter.

Not Applicable.

Indicate the number of shares outstanding for each of the registrant's class of
common stock, as of the latest practicable date.

Not Applicable.

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                       DOCUMENTS INCORPORATED BY REFERENCE

None.



         PART I

         ITEM 1.           BUSINESS

                           For information with respect to the underlying
                           securities held by PreferredPLUS Trust Series ATT-1,
                           please refer to AT&T Corp.'s (Commission file number
                           001-01105) 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 1024, 450 Fifth Street,
                           NW, 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 450 Fifth
                           Street, NW, 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 your
                           investment were 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.

         ITEM 2.           PROPERTIES

                           None.

         ITEM 3.           LEGAL PROCEEDINGS

                           None.

         ITEM 4.           SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

                           None.


                                       2
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         PART II

         ITEM 5.           MARKET FOR REGISTRANT'S COMMON EQUITY, RELATED
                           STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY
                           SECURITIES

                           The Trust Certificates issued by PreferredPLUS Trust
                           Series ATT-1 are represented by one or more physical
                           certificates registered in the name of Cede & Co.,
                           the nominee of the Depository Trust Company. The
                           Trust Certificates are listed on the New York Stock
                           Exchange.

         ITEM 6.           SELECTED FINANCIAL DATA

                           Not Applicable.

         ITEM 7.           MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                           CONDITION AND RESULTS OF OPERATIONS

                           Not Applicable.

         ITEM 7A.          QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET
                           RISK

                           Not Applicable.

         ITEM 8.           FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

                           Not Applicable.

         ITEM 9.           CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON
                           ACCOUNTING AND FINANCIAL DISCLOSURE

                           None.

         ITEM 9A.          CONTROLS AND PROCEDURES

                           The Registrant has procedures so as to provide
                           reasonable assurance that its future Exchange Act
                           filings will be filed within the applicable time
                           periods.


                                       3
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         PART III

         ITEM 10.          DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

                           Not Applicable.

         ITEM 11.          EXECUTIVE COMPENSATION

                           Not Applicable.

         ITEM 12.          SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND
                           MANAGEMENT AND RELATED STOCKHOLDER MATTERS

                           (a)      Securities Authorized For Issuance Under
                                    Equity Compensation Plans: None.
                           (b)      Security Ownership Of Certain Beneficial
                                    Owners: None.
                           (c)      Security Ownership Of Management: Not
                                    Applicable.
                           (d)      Changes In Control: None.

         ITEM 13.          CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

                           None.

         ITEM 14.          PRINCIPAL ACCOUNTING FEES AND SERVICES

                           Not Applicable.


                                       4
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         PART IV

         ITEM 15.          EXHIBITS, FINANCIAL STATEMENT SCHEDULES

                           (a)(1)   Financial Statements: Not Applicable

                           (a)(2)   Financial Statement Schedules: Not
                                    Applicable

                           (a)(3)   List of Exhibits

                           The following exhibits are filed as part of, and
                           incorporated by reference into this Annual Report on
                           Form 10-K:

                                    31.1     Certification of President of
                                             Registrant dated March 29, 2005,
                                             pursuant to Rules 13a-14 and 15d-14
                                             under the Securities Exchange Act
                                             of 1934, as adopted pursuant to
                                             Section 302 of the Sarbanes-Oxley
                                             Act of 2002, with respect to the
                                             Registrant's Annual Report on Form
                                             10-K for the year ended December
                                             31, 2004.

                                    99.1     Trustee's Annual Compliance
                                             Certificate dated March 24, 2005.

                                    99.2     Report of Deloitte & Touche LLP,
                                             Independent Registered Public
                                             Accounting Firm dated March 25,
                                             2005, Registrant's Assertion on
                                             Compliance with PPLUS Minimum
                                             Servicing Standards dated March 25,
                                             2005 and PPLUS Minimum Servicing
                                             Standards.

                                    99.3     Report of Ernst & Young LLP,
                                             Independent Registered Public
                                             Accounting Firm dated March 14,
                                             2005, The Bank of New York's
                                             Assertion on Compliance with PPLUS
                                             Minimum Servicing Standards dated
                                             March 14, 2005 and PPLUS Minimum
                                             Servicing Standards.

                           (b)      Exhibits

                                    The Registrant hereby files as part of this
                                    Annual Report on Form 10-K the exhibits
                                    listed in Item 15(a)(3) set forth above.

                           (c)      Financial Statement Schedules

                                    Not applicable.


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                                   SIGNATURES

                  Pursuant to the requirements of Section 13 or 15(d) 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: March 29, 2005                      By:    /s/ Stephan Kuppenheimer
                                             -----------------------------------
                                               Name:    Stephan Kuppenheimer
                                               Title:   President