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                       SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

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

                                   FORM 8-A/A

                                AMENDMENT NO.  3


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

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

                               CABOT CORPORATION
               (Exact name of registrant as specified in charter)

               Delaware                      04-2271897
          (State of incorporation          (I.R.S. employer
            or organization)               identification no.)

                                75 State Street
                             Boston, Massachusetts
                    (Address of principal executive offices)

                                   02109-1806
                                   (zip code)   

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

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

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

Preferred Stock Purchase Rights      New York Stock Exchange
                                     Boston Stock Exchange
                                     Pacific Stock Exchange


        If this Form relates to the registration of a class of debt securities
and is effective upon filing pursuant to General Instruction A.(c)(1), please
check the following box. / /


        If this Form relates to the registration of a class of debt securities
and is to become effective simultaneously with the effectiveness of a
concurrent registration statement under the Securities Act of 1933 pursuant to
General Instruction A.(c)(2), please check the following box. / /


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

                                     None
- -------------------------------------------------------------------------------
                               (Title of Class)


                              Page 1 of 7 Pages
                           Exhibit Index on Page 4
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        The registrant hereby amends the following items, financial statements,
exhibits or other portions of its Registration Statement on Form 8-A dated
December 2, 1986 (File No. 1-5667), as amended as of August 12, 1988 and as
further amended by the registrant's Form 8, Amendment No. 2 to Form 8-A, dated
November 19, 1990 (File No. 1-5667) as follows:


   Item 1.   Description of Securities to be Registered.
             ------------------------------------------

        On November 10, 1995, the Board of Directors of Cabot Corporation, a
Delaware corporation (the "Corporation"), approved the redemption of all the
outstanding rights to purchase shares of the Corporation's Series A Junior
Participating Preferred Stock, par value $1.00 per share (the "Old Rights"),
under the Rights Agreement, dated as of November 14, 1986, as amended and
restated as of August 12, 1988, and as further amended as of November 15, 1990
between the Corporation and The First National Bank of Boston, as Rights 
Agent.  The record date for payment of the redemption price for the Old Rights, 
equal to $.05 for each share of the Corporation's common stock, is the close of
business on November 24, 1995.  As a result, the right to exercise the Old
Rights will terminate on such date and the only right of the holders of the Old
Rights thereafter is to receive the redemption price.


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

           1.   Rights Agreement, dated as of November 14, 1986, as amended and
restated as of August 12, 1988, and as further amended as of November 15, 1990,
between Cabot Corporation and The First National Bank of Boston, as Rights
Agent, which includes, as Exhibit A thereto, the Certificate of Designation,
Preferences and Rights of Series A Junior Participating Preferred Stock, as
Exhibit B thereto, the Form of Rights Certificate and as Exhibit C thereto, the
Summary of Rights to Purchase Preferred Stock (incorporated by reference to
Exhibit 1 to the registrant's Registration Statement on Form 8-A dated December
2, 1986 (File No. 1-5667), Exhibit 1 to the registrant's Current Report on Form
8-K dated August 12, 1988 (File No. 1-5667) and Exhibit 3 to the registrant's
Form 8, Amendment No. 2 to Form 8-A, dated November 19, 1990 (File No. 1-
5667)).

           2.   Press Release dated November 10, 1995 announcing redemption of 
the Old Rights.




                              Page 2 of 7 Pages
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                                   SIGNATURE

        Pursuant to the requirements of Section 12 of the Securities Exchange
Act of 1934, the registrant has duly caused this amendment to a Registration
Statement on Form 8-A to be signed on its behalf by the undersigned, thereto
duly authorized.

                                        CABOT CORPORATION


                                        By:  /s/ Kennett F. Burnes
                                             ------------------------
                                             Name:  Kennett F. Burnes
                                             Title: President

Dated:  November 27, 1995




                              Page 3 of 7 Pages
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                                 EXHIBIT INDEX
                                 -------------

Exhibit Number Exhibit Page - ------ ------- ---- 1. Rights Agreement, dated as of November N/A 14, 1986, as amended and restated as of August 12, 1988, and as further amended as of November 15, 1990, between Cabot Corporation and The First National Bank of Boston, as Rights Agent, which includes, as Exhibit A thereto, the Certificate of Designation, Preferences and Rights of Series A Junior Participating Preferred Stock, as Exhibit B thereto, the Form of Rights Certificate and as Exhibit C thereto, the Summary of Rights to Purchase Preferred Stock (incorporated by reference to Exhibit 1 to the registrant's Registration Statement on Form 8-A dated December 2, 1986 (File No. 1-5667), Exhibit 1 to the registrant's Current Report on Form 8-K dated August 12, 1988 (File No. 1-5667) and Exhibit 3 to the registrant's Form 8, Amendment No. 2 to Form 8-A, dated November 19, 1990 (File No. 1-5667)). 2. Press Release dated November 10, 1995 6 announcing redemption of the Old Rights.
Page 4 of 7 Pages
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                                                                      EXHIBIT 2

                                         Contact: Kathryn D. Cadigan
                                                  Director, Investor Relations
                                                  (617) 342-6366


FOR IMMEDIATE RELEASE
November 10, 1995

                    CABOT REPLACES SHAREHOLDER RIGHTS PLAN

Boston, MA -- Cabot Corporation (CBT/NYSE) announced today that its Board of
Directors has adopted a new shareholder rights plan to replace the existing
1986 shareholder rights plan. Simultaneously, the Board authorized the
redemption of the existing rights for a redemption price equal to $.05 per
share of common stock.

The new plan is designed to protect against abusive takeover tactics. It is not
adopted in response to any specific threat, but rather as a result of the
periodic review of the Company's takeover response readiness.

Under the new plan, each shareholder will receive a dividend of one New Right
for each share of the Company's outstanding common stock. Each New Right will
entitle the holder to purchase one one-hundredth of a share of the Company's
Series A Junior Participating Preferred Stock at an initial exercise price of
$200.

Initially, the New Rights will be attached to the Company's common stock and
are not exercisable. The New Rights will become detached from the common stock
and immediately exercisable 10 days after any person or group becomes the
beneficial owner of 15% or more of the Company's common stock or any person or
group announces a tender offer or exchange offer that would result in that same
beneficial ownership level, other than pursuant to certain permitted offers.
Members of the Cabot family and related Cabot family entities which
individually or in the aggregate beneficially own 15% or more of the common
stock are "grandfathered" from triggering the New Rights, unless they form a
"group" with non-grandfathered persons beneficially owning, in the aggregate,
in excess of 1% of the then outstanding common stock.

If a buyer (other than a grandfathered person) acquires 15% or more of the
Company's outstanding common stock (except pursuant to a "permitted offer"
approved by the Board of Directors), each New Right (other than New Rights
owned by such buyer) will entitle its holder to purchase the Company's common
stock at a price discounted from the then market price. In addition, if the
Company is acquired in a merger or other business combination transaction after
such an acquisition, each New Right (other than New Rights owned by the buyer)
will entitle its holder to purchase the acquiring company's shares at a
discount.

                              Page 6 of 7 Pages

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The record date for determining shareholders entitled to receive the
distribution of New Rights will be at 5 p.m. on November 24, 1995; shares of
common stock that are newly issued after that date will also have New Rights
attached until the New Rights separate from the common stock. The New Rights
will expire on November 10, 2005. The Company may redeem the New Rights at any
time prior to the 10th day after a buyer acquires 15%, and under certain other
circumstances, for $.01 per New Right. The distribution of New Rights is not
taxable to shareholders.

The payment of the redemption price for the existing rights, the equivalent of
a cash dividend of $0.05 per share of the Company's common stock, will be made
on December 8, 1995 to shareholders of record on November 24, 1995.

Cabot Corporation has global operations in specialty chemicals and materials,
and energy.




                              Page 7 of 7 Pages