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                                                        ITEM 14(a)3,EXHIBIT 2(b)

                               FIRST AMENDMENT TO

                          AGREEMENT AND PLAN OF MERGER


         THIS FIRST AMENDMENT TO AGREEMENT AND PLAN OF MERGER ("Amendment") by
and among Tesoro Petroleum Corporation, a Delaware corporation ("Parent"), CNRG
Acquisition Corp., a Delaware corporation ("Sub") and Coastwide Energy
Services, Inc., a Delaware corporation ("Company") is effective February 19,
1996, and amends that certain Agreement and Plan of Merger dated as of November
20, 1995, by and among Parent, Sub and Company (the "Agreement").  Unless
defined in this Amendment, capitalized terms shall have the meaning ascribed
thereto in the Agreement.

                                    RECITALS

         WHEREAS, Parent, Sub and Coastwide desire to clarify certain aspects
of the Exchange of Certificates provisions of the Agreement to better reflect
the intent of the parties:

         NOW THEREFORE, for good and valuable consideration, the receipt of
sufficiency of which is hereby acknowledged by Parent, Sub and Company, Parent,
Sub and Company agree as follows:

                                   AGREEMENT

         1.      Section 2.2.(b) of the Agreement is deleted in its entirety
and replaced with the following:

                 Payment of Merger Consideration.  Parent shall take all steps
                 necessary to enable and cause there to be provided to the
                 Exchange Agent at the Effective Time of the Merger,
                 certificates for the Parent Shares issued upon the conversion
                 of the Shares pursuant to Section 2.1.  Parent or the
                 Surviving Corporation shall timely make available to the
                 Exchange Agent the cash component of the Merger Consideration.

         2.      The last two sentences of Section 2.2(c) of the Agreement are
deleted in their entirety and replaced with the following:



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                 Until surrendered as contemplated by this Section 2.2, each
                 Certificate shall be deemed from and after the Effective Time,
                 for all corporate purposes, other than the payment of
                 dividends and distributions declared prior to the Merger, to
                 evidence the ownership of the number of full shares of Parent
                 Common Stock into which the shares represented by such
                 Certificate shall have been converted pursuant to this Section
                 II.

         3.      The first sentence of Section 2.2(e) of the Agreement is
deleted in its entirety and replaced with the following:

                 All Parent Shares exchanged upon the surrender of Certificates
                 in accordance with the terms of this Article II, together with
                 any dividends payable thereon to the extent contemplated by
                 this Section 2.2, shall be deemed to have been exchanged and
                 paid in full satisfaction of all rights pertaining to the
                 Shares theretofore represented by such Certificates and, at
                 the Effective Time of the Merger, there shall be no further
                 registration of transfers on the stock transfer books of the
                 Surviving Corporation of the Shares that were outstanding
                 immediately prior to the Effective Time of the Merger.

         4.      Except as specifically amended by this Amendment, the
Agreement shall remain as originally written.  The Agreement shall not be
further amended, except by an instrument in writing signed by all parties to
the Agreement.


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                                        TESORO PETROLEUM CORPORATION
                                        
                                        By: /s/ BRUCE A. SMITH
                                           -----------------------------------
                                                Bruce A. Smith, President and
                                                Chief Executive Officer
                                        
                                        
                                        CNRG ACQUISITION CORP.
                                        
                                        By: /s/ BRUCE A. SMITH
                                           -----------------------------------
                                                Bruce A. Smith, President and
                                                Chief Executive Officer
                                        
                                        
                                        COASTWIDE ENERGY SERVICES, INC.
                                        
                                        By: /s/ STEPHEN A. WELLS 
                                           -----------------------------------
                                                Stephen A. Wells, President



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