SECURITIES AND EXCHANGE COMMISSION
                     Washington, D.C.  20549



                            FORM 8-A/A


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


                      Diamond Shamrock, Inc.
      (Exact name of registrant as specified in its charter)


               Delaware                           74-2456753    
(State of Incorporation or organization)         (IRS Employer
                                              Identification No.)


9830 Colonnade Boulevard, San Antonio, TX           78230
(Address of principal executive offices)          (Zip Code)


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


Rights to Purchase Series A Junior
Participating Preferred Stock          New York Stock Exchange   


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


                               None                              
                         (Title of Class)

          This Amendment to Registration Statement on Form 8-A/A
amends the information contained in the Registration Statement on
Form 8-A, dated March 6, 1990 ("Registration Statement"), of Diamond
Shamrock, Inc. ("Diamond Shamrock") and is being filed pursuant to
Rule 12b-15 promulgated under the Securities and Exchange Act of
1934, as amended.  The capitalized terms not otherwise defined are
defined as set forth in the Registration Statement.

          ITEM 1.   Description of Registrant's Securities to be
                    Registered.

          ITEM 1 is hereby amended as follows:

          (a)  The last sentence of the first paragraph is amended
to read in its entirety as follows:

               The description and terms of the Rights are set forth
               in a Rights Agreement, dated as of March 6, 1990, as
               amended by Amendment to Rights Agreement, dated as of
               September 22, 1996 (collectively, the "Rights
               Agreement"), between the Company and Ameritrust
               Company National Association, as rights agent
               ("Ameritrust"; Ameritrust together with any successor
               rights agent, the "Rights Agent").

          (b)  The third to last paragraph is amended by adding the
following at the end thereof:

               Pursuant to this authority, the Company executed and
               delivered an Amendment to Rights Agreement, dated as
               of September 22, 1996, (a) to make the Rights
               inapplicable to the Agreement and Plan of Merger,
               dated as of September 22, 1996 (the "Merger
               Agreement"), between Ultramar Corporation, a Delaware
               corporation ("Ultramar"), and the Company pursuant to
               which, among other things, the Company will be merged
               with and into Ultramar (the "Merger"), and the other
               transactions contemplated thereby, (b) to make the
               Rights inapplicable to the Stock Option Agreement
               dated as of September 22, 1996, (the "Company
               Option"), between Ultramar and the Company, whereby
               the Company has granted Ultramar the option to
               purchase up to 5,858,500 Common Shares (representing
               slightly less than 20% of the outstanding Common
               Shares but subject to a cap on such number), and the
               transactions contemplated thereby and (c) provide
               that neither Ultramar nor any of Ultramar's wholly
               owned subsidiaries nor any assignee or transferee of
               Ultramar under the Company Option is an Acquiring
               Person or an Adverse Person, and that no Distribution
               Date, Share Acquisition Date or Triggering Event
               occurs solely as a result of the execution and
               delivery of the Merger Agreement and the Company
               Option, the consummation of the Merger or the
               consummation of the other transactions contemplated
               by the Merger Agreement and the Company Option.

          ITEM 2.   Exhibits.  ITEM 2 is hereby amended to add the
                    following at the end thereof:

               8.   Amendment to Rights Agreement (incorporated
               herein by reference from Exhibit 4(a) to the
               Company's Current Report on Form 8-K, dated September
               26, 1996, filed under Commission File No. 1-9409).

                            SIGNATURES

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

                              DIAMOND SHAMROCK, INC.

                              By:  /s/ GARY E. JOHNSON
                                   Gary E. Johnson
                                   Vice President and Controller

Dated:  October 23, 1996