SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                                ---------------
                                   FORM 8-A

               FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                   PURSUANT TO SECTION 12(b) OR 12(g) OF THE
                        SECURITIES EXCHANGE ACT OF 1934

                           Merrill Lynch & Co., Inc.
            (Exact name of registrant as specified in its charter)

                Delaware                                          13-2740599
- ----------------------------------------                     -------------------
(State of incorporation or organization)                       (I.R.S. Employer
                                                             Identification No.)
        4 World Financial Center
           New York, New York                                       10080
- ----------------------------------------                          ----------
(Address of principal executive offices)                          (Zip Code)



If this form relates to the             If this form relates to the
registration of a class of              registration of a class of
securities pursuant to Section          securities pursuant to Section
12(b) of the Exchange Act and is        12(g) of the Exchange Act and is
effective pursuant to General           effective pursuant to General
Instruction A.(c), please check the     Instruction A.(d), please check the
following box. |X|                      following box. |_|

Securities Act registration statement file number to which this form relates:
333-122639

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

Title of each class                      Name of each exchange on which
to be so registered                      each class is to be registered
- -------------------                      ------------------------------


50/150 Nikkei-225(R) Index Notes         The American Stock Exchange
due October 7, 2009

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

(None)




Item 1.           Description of Registrant's Securities to be Registered.
                  -------------------------------------------------------

         The description of the general terms and provisions of the 50/150
Nikkei-225(R) Index Notes due October 7, 2009, issued by Merrill Lynch & Co.,
Inc. (the "Notes"), set forth in the Preliminary Pricing Supplement, dated
February 6, 2006, and the Prospectus Supplement and Prospectus, each dated
February 25, 2005, attached hereto as Exhibit 99(A), is hereby incorporated by
reference and contains certain proposed terms and provisions. The description
of the Notes contained in the Pricing Supplement to be filed pursuant to Rule
424(b) under the Securities Act of 1933, as amended, under Registration
Statement Number 333-122639, which will contain the final terms and provisions
of the Notes, including the maturity date of the Notes, is hereby deemed to be
incorporated by reference into this Registration Statement and to be a part
hereof.

Item 2.           Exhibits.
                  --------

                  99 (A)   Preliminary Pricing Supplement, dated
                           February 6, 2006, and the Prospectus Supplement
                           and Prospectus, each dated February 25, 2005
                           (incorporated by reference to registrant's
                           filing pursuant to Rule 424(b)).

                  99 (B)   Form of Note.

                  99 (C)   Copy of Indenture between Merrill Lynch & Co., Inc.
                           and JPMorgan Chase Bank, N.A., dated as of April 1,
                           1983, as amended and restated.*

         Other securities issued by Merrill Lynch & Co., Inc. are listed on
the American Stock Exchange.




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*    Exhibit 99 (C) is incorporated by reference from Exhibit (3) to
     Registrant's Registration Statement on Form 8-A dated July 20, 1992.



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                                   SIGNATURE

         Pursuant to the requirements of Section 12 of the Securities Exchange
Act of 1934, the registrant has caused this registration statement to be
signed on its behalf by the undersigned, thereto duly authorized.

                           MERRILL LYNCH & CO., INC.



                           By: /s/ Judith A. Witterschein
                               --------------------------------------
                               Judith A. Witterschein
                               Secretary


Date:  March 2, 2006


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                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549




                           MERRILL LYNCH & CO., INC.





                                   EXHIBITS
                                      TO
                         FORM 8-A DATED MARCH 2, 2006





                               INDEX TO EXHIBITS
                               -----------------

Exhibit No.
99 (A)           Preliminary Pricing Supplement, dated February 6, 2006,
                 and the Prospectus Supplement and Prospectus, each dated
                 February 25, 2005 (incorporated by reference to
                 registrant's filing pursuant to Rule 424(b)).

99 (B)           Form of Note.

99 (C)           Copy of Indenture between Merrill Lynch & Co., Inc. and
                 JPMorgan Chase Bank, N.A., dated as of April 1, 1983, as
                 amended and restated.*

- --------
*    Exhibit 99 (C) is incorporated by reference from Exhibit (3) to
     Registrant's Registration Statement on Form 8-A dated July 20, 1992.



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