Exhibit 4.6
     
     
                    ULTRAMAR CORPORATION
                   SECRETARY'S CERTIFICATE
     
     
          I, Patrick J. Guarino, Senior Vice President, General Counsel
     and Secretary of Ultramar Corporation, a Delaware corporation (the
     "Corporation"), hereby certify that meetings of the Board of
     Directors of the Corporation were duly called and held on
     September 22, 1996, and December 3, 1996, at each of which a quorum
     was present and voting throughout, and that at such meetings
     resolutions on motions duly made and seconded were unanimously
     adopted and are now in full force and effect which approved the
     following amendments to the By-laws of the Corporation.
     
          The By-laws of the Corporation are hereby amended so that they
     read in their entirety as they exist on the date hereof except
     that:
     
          (i) Section 1 of Article IV of such by-laws reads in its
     entirety as follows:
     
     "SECTION 1.  General.  The officers of the Corporation
     shall be chosen by the Board of Directors and shall be a
     Chairman of the Board of Directors (who must be a director),
     a Vice Chairman of the Board of Directors (who also must be a
     director), a Chief Executive Officer, a President and Chief
     Operating Officer, a Secretary and a Treasurer.  The Board of
     Directors, in its discretion, may also choose one or more Vice
     Presidents (including, without limitation, Assistant,
     Executive, Senior and Group), Assistant Secretaries, Assistant
     Treasurers and other officers.  Any number of offices may be
     held by the same person, unless otherwise prohibited by law,
     the Certificate of Incorporation or these By-laws.  The
     officers of the Corporation need not be stockholders of the
     Corporation nor, except in the case of the Chairman of the
     Board of Directors and the Vice Chairman of the Board of
     Directors, need such officers be directors of the
     Corporation.";
     
          (ii) Sections 4, 5 and 6 of Article IV of such by-laws read in
     their entirety as follows:
     
          "SECTION 4.  Chairman and Vice Chairman of the Board of
          Directors.  The Chairman of the Board of Directors shall
          preside at all meetings of the stockholders and of the Board
          of Directors.  Except where by law the signature of the Chief
          Executive Officer or the President and Chief Operating Officer
          is required, the Chairman of the Board of Directors shall
          possess the same power as the Chief Executive Officer or the
          President and Chief Operating Officer to sign all contracts,
          certificates and other instruments of the Corporation which
          may be authorized by the Board of Directors.  During the
          absence or disability of the Chief Executive Officer or
          President and Chief Operating Officer, the Chairman of the
          Board of Directors shall exercise all the powers and discharge
          all the duties of the Chief Executive Officer or President and
          Chief Operating Officer, as applicable.  The Chairman of the
          Board of Directors shall also perform such other duties and
          may exercise such other powers as from time to time may be
          assigned to him by these By-laws or by the Board of Directors. 
          The Vice Chairman of the Board of Directors shall, during the
          absence or disability of the Chairman of the Board of
          Directors, have the powers and perform the duties of the
          Chairman of the Board of Directors and shall also perform such
          other duties and may exercise such other powers as from time
          to time may be assigned to him by the Board of Directors. 
          Notwithstanding anything in these By-laws to the contrary, the
          Chairman of the Board of Directors and the Vice Chairman of
          the Board of Directors may only be removed from such offices
          (but not as directors) by an affirmative vote of the majority
          of the entire Board of Directors.
     
          "SECTION 5.  Chief Executive Officer and President and
          Chief Operating Officer.  The Chief Executive Officer shall,
          subject to the control of the Board of Directors and the
          Chairman of the Board of Directors (or during his absence or
          disability, the Vice Chairman of the Board of Directors), have
          general supervision of the business and affairs of the
          Corporation and shall see that all orders and resolutions of
          the Board of Directors are carried into effect.  He shall
          possess the power to execute all bonds, mortgages, contracts
          and other instruments of the Corporation requiring a seal,
          under the seal of the Corporation, except where required or
          permitted by law to be otherwise signed and executed and
          except that the other officers of the Corporation may sign and
          execute documents when so authorized by these By-laws, the
          Board of Directors or the Chief Executive Officer.  In the
          absence or disability of both the Chairman of the Board of
          Directors and the Vice Chairman of the Board of Directors, the
          Chief Executive Officer shall preside at all meetings of the
          stockholders and the Board of Directors.  The Chief Executive
          Officer shall also perform such other duties and may exercise
          such other powers as from time to time may be assigned to him
          by these By-laws or by the Board of Directors and,
          notwithstanding any other provision of these By-laws, the
          Chief Executive Officer may appoint officers of the
          Corporation pursuant to and in accordance with authority
          granted to him from time to time by the Board of Directors. 
          The President and Chief Operating Officer (hereinafter
          sometimes referred to only as the "President") shall, subject
          to the direction and  control of the Board of Directors, and
          the supervision of the Chairman of the Board of Directors (or
          during his absence or disability, the Vice Chairman of the
          Board of Directors) and the Chief Executive Officer, have
          general supervision of the business operations of the
          Corporation.  The President and Chief Operating Officer shall,
          during the absence or disability of the Chief Executive
          Officer, have the powers and perform the duties of the Chief
          Executive Officer and shall also perform such other duties and
          may exercise such other powers as from time to time may be
          assigned to him by these By-laws or the Board of Directors. 
          Notwithstanding anything in these By-laws to the contrary, the
          Chief Executive Officer and the President and Chief Operating
          Officer may only be removed from such offices by an
          affirmative vote of the majority of the entire Board of
          Directors.
     
          "SECTION 6.  Vice Presidents.  At the request of the
          Chief Executive Officer or in his absence or in the event of
          his inability or refusal to act (and only in the absence of
          the Chairman of the Board of Directors, Vice Chairman of the
          Board of Directors and President and Chief Operating Officer
          who would otherwise have the powers and perform the duties of
          the Chief Executive Officer), the Vice President or the Vice
          Presidents if there is more than one (in the order designated
          by the Board of Directors) shall perform the duties of the
          Chief Executive Officer, and when so acting, shall have all
          the powers of and be subject to all the restrictions upon the
          Chief Executive Officer.  Each Vice President shall perform
          such other duties and have such other powers as the Board of
          Directors from time to time may prescribe.  If there be no
          Chairman of the Board of Directors, no Vice Chairman of the
          Board of Directors, no President and Chief Operating Officer
          and no Vice President, the Board of Directors shall designate
          the officer of the Corporation who, in the absence of the
          Chief Executive Officer or in the event of the inability or
          refusal of the Chief Executive Officer to act, shall perform
          the duties of the Chief Executive Officer, and when so acting,
          shall have all the powers of and be subject to all the
          restrictions upon the Chief Executive Officer."; and
     
         (iii) Article VIII of such by-laws reads in its entirety as
     follows:

                                  ARTICLE VIII
                                Indemnification
     
          "SECTION 1.  Right to Indemnification.  Each person who was or
     is made a party or is threatened to be made a party to or is
     otherwise involved in any action, suit or proceeding, whether
     civil, criminal, administrative or investigative (hereinafter a
     "proceeding"), by reason of the fact that he or she is or was a
     director or an officer of the Corporation or is or was serving at
     the request of the Corporation as a director, officer, employee or
     agent of another corporation or of a partnership, joint venture,
     trust or other enterprise, including service with respect to an
     employee benefit plan (hereinafter an "indemnitee"), whether the
     basis of such proceeding is alleged action in an official capacity
     as a director, officer, employee or agent or in any other capacity
     while serving as a director, officer, employee or agent, shall be
     indemnified and held harmless by the Corporation to the fullest
     extent permitted or required by the Delaware General Corporation
     Law, as the same exists or may hereafter be amended (but, in the
     case of any such amendment, only to the extent that such amendment
     permits the Corporation to provide broader indemnification rights
     than such law permitted the Corporation to provide prior to such
     amendment), against all expense, liability and loss (including
     attorneys' fees, judgments, fines, ERISA excise taxes or penalties
     and amounts paid in settlement) reasonably incurred or suffered by
     such indemnitee in connection therewith; provided, however, that,
     except as provided in Section 3 of this Article VIII with respect
     to proceedings to enforce rights to indemnification, the
     Corporation shall indemnify any such indemnitee in connection with
     a proceeding (or part thereof) initiated by such indemnitee only if
     such proceeding (or part thereof) was authorized by the Board of
     Directors of the Corporation.
     
          "SECTION 2.  Right to Advancement of Expenses.  The right to
     indemnification conferred in Section 1 of this Article VIII shall
     include the right to be advanced by the Corporation the expenses
     (including, without limitation, attorneys' fees and expenses)
     incurred in defending any such proceeding in advance of its final
     disposition (hereinafter an "advancement of expenses"); provided,
     however, that, if the Delaware General Corporation Law so requires,
     an advancement of expenses incurred by an indemnitee in his or her
     capacity as a director or officer (and not in any other capacity in
     which service was or is rendered by such indemnitee, including,
     without limitation, service to an employee benefit plan) shall be
     made only upon delivery to the Corporation of an undertaking
     (hereinafter an "undertaking"), by or on behalf of such indemnitee,
     to repay all amounts so advanced if it shall ultimately be
     determined by final judicial decision from which there is no
     further right to appeal (hereinafter a "final adjudication") that
     such indemnitee is not entitled to be indemnified for such expenses
     under this Section 2 or otherwise.  The rights to indemnification
     and to the advancement of expenses conferred in Sections 1 and 2 of
     this Article VIII shall be contract rights and such rights shall
     continue as to an indemnitee who has ceased to be a director,
     officer, employee or agent and shall inure to the benefit of the
     indemnitee's heirs, executors and administrators.
     
          "SECTION 3.  Right of Indemnitee to Bring Suit.  If a claim
     under Section 1 or 2 of this Article VIII is not paid in full by
     the Corporation within 60 calendar days after a written claim has
     been received by the Corporation, except in the case of a claim for
     an advancement of expenses, in which case the applicable period
     shall be 20 calendar days, the indemnitee may at any time
     thereafter bring suit against the Corporation to recover the unpaid
     amount of the claim.  If successful in whole or in part in any such
     suit, or in a suit brought by the Corporation to recover an
     advancement of expenses pursuant to the terms of an undertaking,
     the indemnitee shall be entitled to be paid also the expense of
     prosecuting or defending such suit.  In (i) any suit brought by the
     indemnitee to enforce a right to indemnification hereunder (but not
     in a suit brought by the indemnitee to enforce a right to an
     advancement of expenses) it shall be a defense that, and (ii) any
     suit brought by the Corporation to recover an advancement of
     expenses pursuant to the terms of an undertaking, the Corporation
     shall be entitled to recover such expenses upon a final
     adjudication that, the indemnitee has not met any applicable
     standard for indemnification set forth in the Delaware General
     Corporation Law.  Neither the failure of the Corporation (including
     its Board of Directors, independent legal counsel or  stockholders)
     to have made a determination prior to the commencement of such suit
     that indemnification of the indemnitee is proper in the circum-
     stances because the indemnitee has met the applicable standard of
     conduct set forth in the Delaware General Corporation Law, nor an
     actual determination by the Corporation (including its Board of
     Directors, independent legal counsel or stockholders) that the
     indemnitee has not met such applicable standard of conduct, shall
     create a presumption that the indemnitee has not met the applicable
     standard of conduct or, in the case of such a suit brought by the
     indemnitee, be a defense to such suit.  In any suit brought by the
     indemnitee to enforce a right to indemnification or to an
     advancement of expenses hereunder, or brought by the Corporation to
     recover an advancement of expenses pursuant to the terms of an
     undertaking, the burden of proving that the indemnitee is not enti-
     tled to be indemnified, or to such advancement of expenses, under
     this Article VIII or otherwise shall be on the Corporation. 
     
          "SECTION 4.  Non-Exclusivity of Rights.  The rights to
     indemnification and to the advancement of expenses conferred in
     this Article VIII shall not be exclusive of any other right which
     any person may have or hereafter acquire under any statute, the
     Corporation's Certificate of Incorporation, By-laws, agreement,
     vote of stockholders or disinterested directors or otherwise.
     
          "SECTION 5.  Insurance.  The Corporation may maintain
     insurance, at its expense, to protect itself and any director,
     officer, employee or agent of the Corporation or another
     corporation, partnership, joint venture, trust or other enterprise
     against any expense, liability or loss, whether or not the
     Corporation would have the power to indemnify such person against
     such expense, liability or loss under the Delaware General Corpora-
     tion Law.
     
          "SECTION 6.  Indemnification of Employees and Agents of the
     Corporation.  The Corporation may, to the extent authorized from
     time to time by the Board of Directors, grant rights to indem-
     nification and to the advancement of expenses to any employee or
     agent of the Corporation to the fullest extent of the provisions of
     this Article with respect to the indemnification and advancement of
     expenses of directors and officers of the Corporation."
     
          IN WITNESS WHEREOF, the undersigned has caused this
     Certificate to be duly executed as of December 3, 1996.
     
     
                              /s/ PATRICK J. GUARINO
     
     
                              Patrick J. Guarino
                              Senior Vice President,
                              General Counsel and Secretary 
     
     
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