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                                                                   EXHIBIT 10.35

                              FOURTH AMENDMENT TO
                FIRST AMENDED AND RESTATED MANAGEMENT AGREEMENT
                      BETWEEN DEEPTECH INTERNATIONAL INC.
                       AND LEVIATHAN GAS PIPELINE COMPANY


         This Fourth Amendment dated as of May 1, 1997 (this "Amendment") has
been executed and delivered by the undersigned for the purpose of amending and
extending the First Amended and Restated Management Agreement dated as of June
27, 1994 (the "Agreement", as amended) between DeepTech International Inc. and
Leviathan Gas Pipeline Company.  Unless otherwise defined in the Amendment, all
capitalized terms herein shall have the meanings ascribed to them in the
Agreement.

         WHEREAS, the parties deem it to be in their mutual best interests to
amend and extend the term of the Agreement.

         NOW, THEREFORE, the Parties hereby amend the Agreement as follows:

         1.      Amendment of Article 1.  Article 1 of the Agreement is hereby
                 amended by:

                 a.       Adding the defined term "Extended Term".

                          "Extended Term" means the five (5) year period from
                          the end of the Initial Term.

         2.      Amendment of Subsection 5.1.  Section 5.1 of the Agreement is
                 hereby amended by deleting it in its entirety and replacing it
                 with the following:

                 5.1      Initial and Extended Term.  This Agreement shall be
                          effective from the Effective Date and shall continue
                          for five (5) years thereafter (the "Initial Term");
                          subject, however, to the terms of Section 5.2 hereof.
                          At the end of the Initial Term, this Agreement shall
                          continue in force and effect for the Extended Term;
                          subject, however to the terms of Section 5.2 hereof.
                          At the end of the Extended Term, this Agreement shall
                          continue in force and effect for subsequent one (1)
                          year periods unless terminated by either party
                          pursuant to Section 5.2.

         3.      Amendment of Subsection 5.2 (b).  Section 5.2 (b) of the
                 Agreement is hereby amended by deleting it in its entirety and
                 replacing it with the following:

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                 5.2 (b)  Optional Termination  After the Extended Term, either
                          party may, ninety days prior to any anniversary of
                          the Effective Date, provide to the other Party written
                          notice of its intent to terminate this Agreement on 
                          such anniversary date, whereupon this Agreement shall
                          terminate on the anniversary date specified in such 
                          notice.

         IN WITNESS WHEREOF, the Parties have executed this Amendment effective
as of the date first set forth in the preamble.


DEEPTECH INTERNATIONAL INC.             LEVIATHAN GAS PIPELINE COMPANY, INC.



By:                                     By:                                   
   -----------------------------------     -----------------------------------
   Donald V. Weir                          Grant E. Sims
   Chief Financial Officer                 Chief Executive Officer