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                                                                EXHIBIT 10.68(b)


                FIRST AMENDMENT TO EXECUTIVE EMPLOYMENT AGREEMENT

         This Agreement, entered into on this 12 of March, 1999, and made
effective as of February 1, 1999, by and between ENRON OIL & GAS COMPANY
("Company" or "Employer") and GARY L. THOMAS ("Employee") is an amendment to
that certain Employment Agreement made effective as of September 1, 1998 (the
"Employment Agreement").

         WHEREAS, the parties desire to amend the Employment Agreement as
provided herein;

         NOW, THEREFORE, in consideration thereof and of the mutual covenants
contained herein, the parties agree as follows:

         1.       Article 3, Section 3.5 of the Employment Agreement is hereby
                  deleted in its entirety and the following is substituted
                  therefor:

                  "3.5 Upon an Involuntary Termination of the employment
                  relationship by either Employer or Employee prior to the
                  expiration of the Term, Employee shall be entitled, in
                  consideration of Employee's continuing obligations hereunder
                  after such termination (including, without limitation,
                  Employee's non-competition obligations), to receive the then
                  current Monthly Base Salary as if Employee's employment (which
                  shall cease on the date of such Involuntary Termination) had
                  continued for the full Term of this Agreement. Notwithstanding
                  any other provisions of this Agreement, a termination of the
                  employment relationship by either the Employer or Employee
                  which meets the definition of Involuntary Termination under
                  the Company's Change of Control Severance Plan shall
                  constitute an Involuntary Termination under this Agreement. In
                  the event of such Involuntary Termination which entitles
                  Employee to severance benefits under said Plan, but for the
                  following severance payment by the Company to the Employee,
                  Employee shall receive from the Company a severance benefit
                  under this Agreement equal to the sum of Employee's then
                  current Monthly Base Salary times 12 times 2.99 plus two times
                  the Employee's annual bonus target award under the Company's
                  annual bonus program for the year in which the Change of
                  Control Date occurs. Employee's severance benefit payable
                  under said Plan, if any, shall be determined according to the
                  provisions thereof. Employee shall not be under any duty or
                  obligation to seek or accept other employment following
                  Involuntary Termination and the amounts due Employee hereunder
                  shall not be reduced or suspended if Employee






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                  accepts subsequent employment. Employee's rights under this
                  Section 3.5 are Employee's sole and exclusive rights against
                  Employer, Enron, or their affiliates, and Employer's sole and
                  exclusive liability to Employee under this Agreement, in
                  contract, tort, or otherwise, for any Involuntary Termination
                  of the employment relationship. Employee covenants not to sue
                  or lodge any claim, demand or cause of action against Employer
                  for any sums for Involuntary Termination other than those sums
                  specified in this Section 3.5. If Employee breaches this
                  covenant, Employer shall be entitled to recover from Employee
                  all sums expended by Employer (including costs and attorneys
                  fees) in connection with such suit, claim, demand or cause of
                  action."

         2.       The following sentence shall be inserted at the end of Article
                  7, Section 7.1:

                  "However, upon an Involuntary Termination as defined in the
                  Company's Change of Control Severance Plan, which entitles
                  Employee to severance benefits under said Plan, these
                  non-competition obligations shall expire immediately and have
                  no further force and effect."

         3.       The following new Article 9 shall be inserted at the end of
                  the Employment Agreement:

                  "ARTICLE 9:  U.S. EXCISE TAX INDEMNIFICATION

                        9.1 Indemnification. In the event it shall be determined
                  that any payment or distribution by the Company to or for the
                  benefit of Employee (whether paid or payable or distributed or
                  distributable pursuant to the terms of this Agreement, the
                  Company's Change of Control Severance Plan or otherwise, but
                  determined without regard to any additional payments required
                  under this Article 9) (a "Payment") would be subject to the
                  excise tax imposed by Section 4999 of the United States
                  Internal Revenue Code of 1986, as amended (the "Code"), or any
                  interest or penalties are incurred by Employee with respect to
                  such excise tax (such excise tax, together with any such
                  interest and penalties, are hereinafter collectively referred
                  to as the "Excise Tax"), then Employee shall be entitled to
                  receive an additional payment (a "Gross-Up Payment") in an
                  amount such that after payment by Employee of all taxes
                  (including any interest or penalties imposed with respect to
                  such taxes), including, without limitation, any income and
                  employment taxes (and any interest and penalties imposed with
                  respect thereto) and Excise Tax imposed upon the Gross-Up
                  Payment, Employee retains an amount of the Gross-Up Payment
                  equal to the Excise Tax imposed upon the Payments.

                        9.2 Determination of Amount. Subject to the provisions
                  of Section 9.3, all determinations required to be made under
                  this Article 9,






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                  including whether and when a Gross-Up Payment is required and
                  the amount of such Gross-Up Payment and the assumptions to be
                  utilized in arriving at such determination, shall be made by a
                  public accounting firm chosen by the Company (the "Accounting
                  Firm") which shall provide detailed supporting calculations
                  both to the Company and Employee if requested by either the
                  Company or Employee. All fees and expenses of the Accounting
                  Firm shall be borne solely by the Company. Any determination
                  by the Accounting Firm shall be binding upon the Company and
                  Employee. As a result of the uncertainty in the application of
                  Section 4999 of the Code at the time of the initial
                  determination by the Accounting Firm hereunder, it is possible
                  that Gross-Up Payments which will not have been made by the
                  Company should have been made ("Underpayment"), consistent
                  with the calculations required to be made hereunder. In the
                  event that the Company exhausts its remedies pursuant to
                  Section 9.3 and Employee thereafter is required to make a
                  payment of any additional Excise Tax, the Accounting Firm
                  shall determine the amount of the Underpayment that has
                  occurred and any such Underpayment shall be promptly paid by
                  the Company to or for the benefit of Employee.

                        9.3 Contest of Claims. If the Company elects to contest
                  a claim by the Internal Revenue Service that Excise Tax is due
                  from Employee, Employee shall cooperate fully with the Company
                  in order to effectively contest such claim, including, but not
                  limited to providing information reasonably requested by the
                  Company relating to such claim, accepting legal representation
                  with respect to such claim by an attorney reasonably selected
                  by the Company and permitting the Company to participate in
                  any proceedings relating to such claim. The Company shall bear
                  and pay directly all costs and expenses (including additional
                  interest and penalties) incurred in connection with such
                  contest and shall indemnify and hold Employee harmless, on an
                  after-tax basis, for any Excise Tax or other tax (including
                  interest and penalties with respect thereto) imposed as a
                  result of such representation and payment of costs and
                  expenses.

                        9.4 Advances and Refunds. If the Company directs
                  Employee to pay a claim by the Internal Revenue Service and
                  sue for a refund, the Company shall advance the amount of such
                  payment to Employee on an interest-free basis and shall
                  indemnify and hold Employee harmless, on an after-tax basis,
                  from any Excise Tax or income tax (including interest or
                  penalties with respect thereto) imposed with respect to such
                  advance or with respect to any imputed income with respect to
                  such advance. If, after the receipt by





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                  Employee of an amount advanced by the Company pursuant to this
                  Section 9.4, Employee becomes entitled to receive, and
                  receives, any refund with respect to such claim, Employee
                  shall promptly pay to the Company the amount of such refund
                  (together with any interest paid or credited thereon after
                  taxes applicable thereto). If, after the receipt by Employee
                  of an amount advanced by the Company pursuant to this Section
                  9.4, a determination is made that Employee is not entitled to
                  any refund with respect to such claim, then such advance shall
                  not be required to be repaid and the amount of such advance
                  shall offset, to the extent thereof, the amount of Gross-Up
                  Payment required to be paid."

         This Agreement is the First Amendment to the Employment Agreement, and
the parties agree that all other terms, conditions and stipulations contained in
the Employment Agreement, and any amendments thereto, shall remain in full force
and effect and without any change or modification, except as provided herein.

         IN WITNESS WHEREOF, the parties have duly executed this Agreement as of
the date first above written.

                                   ENRON OIL & GAS COMPANY



                                   By: /s/ PATRICIA EDWARDS
                                      --------------------------------------
                                   Name: Patricia Edwards
                                   Title: V.P. Human Resources & Administration
                                   This 15th day of March, 1999


                                   GARY L. THOMAS


                                       /s/ GARY L. THOMAS
                                   -----------------------------------------
                                   This 12 day of March, 1999