<PAGE>   1
                                                                    EXHIBIT 10.1

                                                                  EXECUTION COPY

================================================================================




                         EL PASO NATURAL GAS COMPANY


                            --------------------


                                $750,000,000
                      REVOLVING CREDIT AND COMPETITIVE
                         ADVANCE FACILITY AGREEMENT


                        DATED AS OF NOVEMBER 4, 1996


                            --------------------



                          THE CHASE MANHATTAN BANK,
                           AS ADMINISTRATIVE AGENT
                            AND CAF ADVANCE AGENT

                                      



================================================================================
<PAGE>   2
                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
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       <S>                                                                    <C>
                                    ARTICLE I

                        DEFINITIONS AND ACCOUNTING TERMS  . . . . . . . . .    1
       SECTION 1.1   Certain Defined Terms  . . . . . . . . . . . . . . . .    1
       SECTION 1.2   Computation of Time Periods  . . . . . . . . . . . . .   17
       SECTION 1.3   Accounting Terms   . . . . . . . . . . . . . . . . . .   17
       SECTION 1.4   References   . . . . . . . . . . . . . . . . . . . . .   17

                                   ARTICLE II

                        AMOUNTS AND TERMS OF THE ADVANCES . . . . . . . . .   18
       SECTION 2.1   The Revolving Credit Advances  . . . . . . . . . . . .   18
       SECTION 2.2   Making the Revolving Credit Advances   . . . . . . . .   18
       SECTION 2.3   Evidence of Debt   . . . . . . . . . . . . . . . . . .   20
       SECTION 2.4   CAF Advances   . . . . . . . . . . . . . . . . . . . .   20
       SECTION 2.5   Procedure for CAF Advance Borrowings   . . . . . . . .   21
       SECTION 2.6   CAF Advance Payments   . . . . . . . . . . . . . . . .   24
       SECTION 2.7   Evidence of Debt   . . . . . . . . . . . . . . . . . .   25
       SECTION 2.8   Fees   . . . . . . . . . . . . . . . . . . . . . . . .   25
       SECTION 2.9   Reduction of the Commitments   . . . . . . . . . . . .   26
       SECTION 2.10  Repayment of Advances  . . . . . . . . . . . . . . . .   26
       SECTION 2.11  Interest on Revolving Credit Advances  . . . . . . . .   26
       SECTION 2.12  Additional Interest on Eurodollar Rate Advances  . . .   27
       SECTION 2.13  Interest Rate Determination  . . . . . . . . . . . . .   28
       SECTION 2.14  Voluntary Conversion of Advances   . . . . . . . . . .   29
       SECTION 2.15  Optional and Mandatory Prepayments   . . . . . . . . .   30
       SECTION 2.16  Increased Costs  . . . . . . . . . . . . . . . . . . .   30
       SECTION 2.17  Increased Capital  . . . . . . . . . . . . . . . . . .   32
       SECTION 2.18  Illegality   . . . . . . . . . . . . . . . . . . . . .   32
       SECTION 2.19  Payments and Computations  . . . . . . . . . . . . . .   33
       SECTION 2.20  Taxes  . . . . . . . . . . . . . . . . . . . . . . . .   34
       SECTION 2.21  Sharing of Payments, Etc.  . . . . . . . . . . . . . .   37
       SECTION 2.22  Use of Proceeds  . . . . . . . . . . . . . . . . . . .   37
       SECTION 2.23  Replacement of Lenders.  . . . . . . . . . . . . . . .   38

                                   ARTICLE III

                     CONDITIONS OF EFFECTIVENESS AND LENDING  . . . . . . .   38
       SECTION 3.1   Conditions Precedent to Effectiveness of
                       this Agreement   . . . . . . . . . . . . . . . . . .   38
       SECTION 3.2   Conditions Precedent to Initial Advances   . . . . . .   39
       SECTION 3.3   Conditions Precedent to Initial Advances to Any
                       Borrowing Subsidiary or Holding  . . . . . . . . . .   40
       SECTION 3.4   Conditions Precedent to Each Borrowing   . . . . . . .   41

                                   ARTICLE IV

                         REPRESENTATIONS AND WARRANTIES   . . . . . . . . .   41
</TABLE>





                                      -i-
<PAGE>   3
<TABLE>
<CAPTION>
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                                                                            ----
       <S>                                                                    <C>
       SECTION 4.1   Representations and Warranties of the Borrowers  . . .   41

                                    ARTICLE V

                           COVENANTS OF THE BORROWERS   . . . . . . . . . .   45
       SECTION 5.1   Affirmative Covenants  . . . . . . . . . . . . . . . .   45
       SECTION 5.2   Negative Covenants   . . . . . . . . . . . . . . . . .   47
       SECTION 5.3   Reporting Requirements   . . . . . . . . . . . . . . .   51
       SECTION 5.4   Restrictions on Material Subsidiaries  . . . . . . . .   54

                                   ARTICLE VI

                                    GUARANTEE . . . . . . . . . . . . . . .   54
       SECTION 6.1   Guarantees   . . . . . . . . . . . . . . . . . . . . .   54
       SECTION 6.2   No Subrogation   . . . . . . . . . . . . . . . . . . .   55
       SECTION 6.3   Amendments, etc. with respect to the Obligations;
                       Waiver of Rights   . . . . . . . . . . . . . . . . .   55
       SECTION 6.4   Guarantee Absolute and Unconditional   . . . . . . . .   56
       SECTION 6.5   Reinstatement  . . . . . . . . . . . . . . . . . . . .   57

                                   ARTICLE VII

                                EVENTS OF DEFAULT . . . . . . . . . . . . .   57
       SECTION 7.1   Event of Default   . . . . . . . . . . . . . . . . . .   57

                                  ARTICLE VIII

               THE ADMINISTRATIVE AGENT AND THE CAF ADVANCE AGENT   . . . .   61
       SECTION 8.1   Authorization and Action   . . . . . . . . . . . . . .   61
       SECTION 8.2   Administrative Agent's and CAF Advance
                       Agent's Reliance, Etc.   . . . . . . . . . . . . . .   61
       SECTION 8.3   Chase and Affiliates   . . . . . . . . . . . . . . . .   62
       SECTION 8.4   Lender Credit Decision   . . . . . . . . . . . . . . .   62
       SECTION 8.5   Indemnification  . . . . . . . . . . . . . . . . . . .   63
       SECTION 8.6   Successor Administrative Agent and CAF Advance Agent     63

                                   ARTICLE IX

                                  MISCELLANEOUS . . . . . . . . . . . . . .   64
       SECTION 9.1   Amendments, Etc.   . . . . . . . . . . . . . . . . . .   64
       SECTION 9.2   Notices, Etc.  . . . . . . . . . . . . . . . . . . . .   65
       SECTION 9.3   No Waiver; Remedies  . . . . . . . . . . . . . . . . .   65
       SECTION 9.4   Costs and Expenses; Indemnity  . . . . . . . . . . . .   65
       SECTION 9.5   Right of Set-Off   . . . . . . . . . . . . . . . . . .   67
       SECTION 9.6   Binding Effect   . . . . . . . . . . . . . . . . . . .   67
</TABLE>





                                      -ii-
<PAGE>   4
<TABLE>
<CAPTION>
                                                                            Page
                                                                            ----
       <S>                                                                    <C>
       SECTION 9.7   Assignments and Participations   . . . . . . . . . . .   67
       SECTION 9.8   Confidentiality  . . . . . . . . . . . . . . . . . . .   70
       SECTION 9.9   Consent to Jurisdiction  . . . . . . . . . . . . . . .   71
       SECTION 9.10  GOVERNING LAW  . . . . . . . . . . . . . . . . . . . .   72
       SECTION 9.11  Rate of Interest   . . . . . . . . . . . . . . . . . .   72
       SECTION 9.12  Effect on Outstanding CAF Advances   . . . . . . . . .   73
       SECTION 9.13  Execution in Counterparts  . . . . . . . . . . . . . .   73
</TABLE>





                                     -iii-
<PAGE>   5

                                    SCHEDULE

Schedule I    Commitments, Addresses, Etc.


                                    EXHIBITS

Exhibit A     Form of Note
Exhibit B     Form of Notice of Borrowing
Exhibit C     Form of CAF Advance Request
Exhibit D     Form of CAF Advance Offer
Exhibit E     Form of CAF Advance Confirmation
Exhibit F     Form of Assignment and Acceptance
Exhibit G     Form of Opinion of [Associate] General Counsel
                of the Company
Exhibit H     Form of Opinion of New York Counsel to the
                Company
Exhibit I     Form of Process Agent Letter
Exhibit J     Form of Joinder Agreement
Exhibit K     Form of Opinion of [Associate] General Counsel of
                the Company
Exhibit L     Form of Opinion of New York Counsel to the Company





                                      -iv-
<PAGE>   6


        $750,000,000 REVOLVING CREDIT AND COMPETITIVE ADVANCE FACILITY
AGREEMENT, dated as of November 4, 1996, among EL PASO NATURAL GAS COMPANY, a
Delaware corporation ("EPNGC"), the several banks and other financial
institutions from time to time parties to this Agreement (the "Lenders"), THE
CHASE MANHATTAN BANK, a New York banking corporation, as administrative agent
(in such capacity, the "Administrative Agent") and as CAF Advance Agent (in
such capacity, the "CAF Advance Agent") for the Lenders hereunder.

              The parties hereto hereby agree as follows:


                                   ARTICLE I

                        DEFINITIONS AND ACCOUNTING TERMS

              SECTION 1.1  Certain Defined Terms.  As used in this Agreement,
the following terms shall have the following meanings (such meanings to be
equally applicable to both the singular and plural forms of the terms defined):

              "Administrative Agent" has the meaning assigned to such term in
       the preamble hereof.

              "Advance" means an advance by a Lender to any Borrower pursuant
       to Article II, and refers to a Base Rate Advance, a Eurodollar Rate
       Advance or a CAF Advance.

              "Affiliate" means as to any Person, any other Person that,
       directly or indirectly, controls, is controlled by or is under common
       control with such Person or is a director or officer of such Person.
       The term "control" (including the terms "controlled by" or "under common
       control with") means, with respect to any Person, the possession, direct
       or indirect, of the power to vote 20% or more of the securities having
       ordinary voting power for the election of directors of such Person or to
       direct or cause the direction of the management and policies of such
       Person, whether through ownership of voting securities or by contract or
       otherwise.

              "Agreement" means this $750,000,000 Revolving Credit and
       Competitive Advance Facility, as amended, supplemented or otherwise
       modified from time to time.

              "Alternate Program" means any program providing for the sale or
       other disposition of trade or other receivables entered into by the
       Company or a Principal Subsidiary (or for purposes of Section 5.2(a)
       only, any Restricted Affiliate) which is in addition to or in
       replacement of the program evidenced by the Receivables Purchase and
       Sale Agreement (whether or not the Receivables Purchase and Sale
       Agreement shall then be in effect), provided that such program is on
       terms (a) substantially similar to the Receivables Purchase and Sale
       Agreement or (b) customary for
<PAGE>   7
                                                                               2




       similar transactions as reasonably determined by the Administrative
       Agent.

              "Applicable LIBO Rate" means in respect of any CAF Advance
       requested pursuant to a LIBO Rate CAF Advance Request, an interest rate
       per annum equal to the rate which appears on Page 3750 of the Telerate
       Service (or any successor or substitute page of such Service, or any
       successor to or substitute for such service providing rate quotations
       comparable to those currently provided on such page of such service, as
       determined by the Administrative Agent from time to time for purposes of
       providing quotations of interest rates applicable to Dollar deposits in
       the London interbank market) as at approximately 11:00 A.M., London
       time, two Business Days prior to the beginning of the period for which
       such CAF Advance is to be outstanding as the rate for Dollar deposits
       with a maturity comparable to such period.

              "Assignment and Acceptance" means an assignment and acceptance
       entered into by a Lender and an Eligible Assignee, and accepted by the
       Administrative Agent, in substantially the form of Exhibit F.

              "Base CD Rate" means the sum of (a) the product of (i) the Three-
       Month Secondary CD Rate and (ii) a fraction, the numerator of which is
       one and the denominator of which is one minus the C/D Reserve Percentage
       and (b) the C/D Assessment Rate.

              "Base Rate" means for any day, a rate per annum (adjusted to the
       nearest 1/16 of 1% or, if there is no nearest 1/16 of 1%, rounded
       upwards to the next highest 1/16 of 1%) equal to the greatest of (a) the
       Prime Rate in effect on such day, (b) the Base CD Rate in effect on such
       day plus 1/2 of 1% and (c) the Effective Federal Funds Rate in effect on
       such day plus 1/2 of 1%.  Any change in the Base Rate due to a change in
       the Prime Rate, the Three-Month Secondary CD Rate or the Effective
       Federal Funds Rate shall be effective as of the opening of business on
       the effective day of such change in the Prime Rate, the Three-Month
       Secondary CD Rate or the Effective Federal Funds Rate, respectively.

              "Base Rate Advance" means an Advance which bears interest as
       provided in Section 2.11(a)(i).

              "Borrowers" means the collective reference to EPNGC, each
       Borrowing Subsidiary and Holding once Holding executes and delivers a
       Joinder Agreement; each, a "Borrower".

              "Borrowing" means a borrowing consisting of Advances of the same
       Type made on the same day by the Lenders, it being understood that there
       may be more than one Borrowing on a particular day.
<PAGE>   8
                                                                               3




              "Borrowing Subsidiary" means each domestic Principal Subsidiary
       of the Company which has been designated by the Company as a "Borrowing
       Subsidiary" by written notice to the Administrative Agent; collectively,
       the "Borrowing Subsidiaries".

              "Burlington" means Burlington Resources Inc., a Delaware
       corporation.

              "Business Day" means a day of the year on which banks are not
       required or authorized to close in New York, New York and, if the
       applicable Business Day relates to any Eurodollar Rate Advances or LIBO
       Rate CAF Advances, on which dealings are carried on in the London
       interbank market.

              "CAF Advance" means an Advance made pursuant to Sections 2.4 and
       2.5.

              "CAF Advance Agent" has the meaning assigned to such term in the
       preamble hereof.

              "CAF Advance Availability Period" means the period from and
       including the Closing Date until the earlier of (a) the date which is 7
       days prior to the Stated Termination Date and (b) the Termination Date.

              "CAF Advance Confirmation" means each confirmation by the
       applicable Borrower of its acceptance of CAF Advance Offers, which CAF
       Advance Confirmation shall be substantially in the form of Exhibit E and
       shall be delivered to the CAF Advance Agent by telecopy.

              "CAF Advance Interest Payment Date" means as to each CAF Advance,
       each interest payment date specified by the applicable Borrower for such
       CAF Advance in the related CAF Advance Request.

              "CAF Advance Lenders" means Lenders from time to time designated
       by the Company, in consultation with the CAF Advance Agent, as CAF
       Advance Lenders as provided in Section 2.4.

              "CAF Advance Maturity Date" means as to any CAF Advance, the date
       specified by the applicable Borrower pursuant to Section 2.5(d)(ii) in
       its acceptance of the related CAF Advance Offer.

              "CAF Advance Offer" means each offer by a CAF Advance Lender to
       make CAF Advances pursuant to a CAF Advance Request, which CAF Advance
       Offer shall contain the information specified in Exhibit D and shall be
       delivered to the CAF Advance Agent by telephone, immediately confirmed
       by telecopy.
<PAGE>   9
                                                                               4



              "CAF Advance Request" means each request by the applicable
       Borrower for CAF Advance Lenders to submit bids to make CAF Advances,
       which request shall contain the information in respect of such requested
       CAF Advances specified in Exhibit C and shall be delivered to the CAF
       Advance Agent in writing, by telecopy, or by telephone, immediately
       confirmed by telecopy.

              "Capitalization" of any Person means the sum (without
       duplication) of (a) consolidated Debt of such Person and its
       consolidated Subsidiaries, plus (b) the aggregate amount of Guaranties
       entered into by such Person and its consolidated Subsidiaries, plus (c)
       the consolidated common and preferred stockholders' equity of such
       Person and its consolidated Subsidiaries.

              "C/D Assessment Rate" means for any day as applied to any Base
       Rate Advance, the annual assessment rate determined by Chase to be
       payable on such day to the Federal Deposit Insurance Corporation (the
       "FDIC") for the FDIC's (or any successor's) insuring time deposits at
       offices of Chase in the United States.

              "C/D Reserve Percentage" means for any day as applied to any Base
       Rate Advance, that percentage (expressed as a decimal) which is in
       effect on such day, as prescribed by the Board of Governors of the
       Federal Reserve System (or any successor) (the "Board"), for determining
       the then current reserve requirement for the Administrative Agent in
       respect of new non-personal time deposits in Dollars having a maturity
       of 30 days or more.

              "Chase" means The Chase Manhattan Bank, a New York banking
       corporation.

              "Closing Date" has the meaning assigned to such term in Section
       3.2.

              "Commitment" means as to any Lender, the obligation of such
       Lender to make Revolving Credit Advances to the Borrowers hereunder in
       an aggregate principal amount at any one time outstanding not to exceed
       the amount set forth opposite such Lender's name on Schedule I (as such
       Schedule I is amended from time to time pursuant to Section 9.7(c)), as
       such amount may be reduced from time to time in accordance with the
       provisions of this Agreement.

              "Commitment Percentage" means as to any Lender at any time, the
       percentage which such Lender's Commitment then constitutes of the
       aggregate Commitments (or, at any time after the Commitments shall have
       expired or terminated, the percentage which the aggregate principal
       amount of such Lender's Advances then outstanding constitutes of the
<PAGE>   10
                                                                               5



       aggregate principal amount of the Advances then outstanding).

              "Company" means (a) at all times prior to Holding becoming a
       Borrower, EPNGC, and (b) thereafter, Holding.

              "Contingent Guaranty" has the meaning assigned to such term in
       the definition of the term "Guaranty" contained in this Section 1.1.

              "Convert", "Conversion" and "Converted" each refers to a
       conversion of Advances of one Type into Advances of another Type
       pursuant to Section 2.13, 2.14 or 2.18.

              "Debt" means, as to any Person, all Indebtedness of such Person
       other than (a) any Project Financing of such Person, (b) in the case of
       the Company or a Principal Subsidiary, any liabilities of the Company or
       such Principal Subsidiary, as the case may be, under any Alternate
       Program, or any document executed by the Company or such Principal
       Subsidiary, as the case may be, in connection therewith and (c) any
       obligations of the Company or a Principal Subsidiary with respect to
       lease payments for the headquarters building of Tennessee located in
       Houston, Texas; provided, however, that for purposes of Article V "Debt"
       shall not include up to an aggregate amount (determined without
       duplication of amount) of $200,000,000 of (i) the amount of optional
       payments in lieu of asset repurchase or other payments to similar
       effect, including extension or renewal payments, on off balance sheet
       leases and (ii) the amount of the purchase price for optional
       acquisition of such asset (in either case, calculated at the lower
       amount payable in respect of such asset under clause (i) or (ii) above).

              "Debt Realignment Plan" means the debt realignment plan described
       under the caption "Debt and Cash Realignment--Debt Realignment" and
       "Unaudited Pro Forma Financial Information--Unaudited Pro Forma Combined
       Financial Statements of El Paso and Tenneco Energy" in the Joint Proxy
       Statement.

              "Dollars" and "$" means dollars in lawful currency of the United
       States of America.

              "Effective Date" means the date on which the conditions precedent
       set forth in Section 3.1 have been satisfied (or compliance therewith
       shall have been waived by the Lenders).

              "Effective Federal Funds Rate" means, for any day, the weighted
       average of the rates on overnight Federal funds transactions with
       members of the Federal Reserve System arranged by Federal funds brokers,
       as published for such day (or, if such day is not a Business Day, for
       the next preceding Business Day) by the Federal Reserve Bank of New
<PAGE>   11
                                                                               6



       York, or, if such rate is not so published for any day which is a
       Business Day, the average of the quotations for such day on such
       transactions received by the Administrative Agent from three Federal
       funds brokers of recognized standing selected by it.

              "Eligible Assignee" means, with respect to any particular
       assignment under Section 9.7, any bank or other financial institution
       approved in writing by the Company expressly with respect to such
       assignment and, except as to such an assignment by Chase so long as
       Chase is the Administrative Agent hereunder, the Administrative Agent as
       an Eligible Assignee for purposes of this Agreement, provided that (i)
       neither the Administrative Agent's nor the Company's approval shall be
       unreasonably withheld and (ii) neither the Administrative Agent's nor
       the Company's approval shall be required if the assignee is another
       Lender or an Affiliate of the assigning Lender.

              "EPNGC" has the meaning assigned to such term in the preamble
       hereof.

              "ERISA" means the Employee Retirement Income Security Act of
       1974, as amended from time to time, and the regulations promulgated and
       rulings issued from time to time thereunder.

              "ERISA Affiliate" means any Person who is a member of the
       Company's controlled group within the meaning of Section 4001(a)(14)(A)
       of ERISA.

              "Eurocurrency Liabilities" has the meaning assigned to that term
       in Regulation D of the Board of Governors of the Federal Reserve System,
       as in effect from time to time.

              "Eurodollar Rate" means, for any Interest Period for each
       Eurodollar Rate Advance comprising part of the same Borrowing, an
       interest rate per annum equal to the rate which appears on Page 3750 of
       the Telerate Service (or on any successor or substitute page of such
       service, or any successor to or substitute for such service providing
       rate quotations comparable to those currently provided on such page of
       such service, as determined by the Administrative Agent from time to
       time for purposes of providing quotations of interest rates applicable
       to Dollar deposits in the London interbank market) as at approximately
       11:00 A.M. (London, England time) two Business Days before the first day
       of such Interest Period as the rate for Dollar deposits with a maturity
       comparable to such Interest Period; provided that if such rate is not
       available at such time for any reason, the Eurodollar Rate for such
       Borrowing for such Interest Period shall be the interest rate per annum
       equal to the average (rounded upward to the nearest whole multiple of
       1/16 of 1% per annum, if such average is not such a
<PAGE>   12
                                                                               7



       multiple) of the rate per annum at which deposits in Dollars are offered
       by the principal office of each of the Reference Lenders in London,
       England, to prime banks in the London interbank market as at
       approximately 11:00 A.M. (London, England time) two Business Days before
       the first day of such Interest Period, in an approximate amount of each
       such Reference Lender's share of the relevant Borrowing for the
       applicable Interest Period. The Eurodollar Rate for the Interest Period
       for each Eurodollar Rate Advance comprising part of the same Borrowing,
       when being determined pursuant to the foregoing proviso clause, shall be
       determined by the Administrative Agent on the basis of applicable rates
       furnished to and received by the Administrative Agent from the Reference
       Lenders two Business Days before the first day of such Interest Period,
       subject, however, to the provisions of Section 2.13.

              "Eurodollar Rate Advance" means an Advance which bears interest
       determined by reference to the Eurodollar Rate, as provided in Section
       2.11(a)(ii).

              "Eurodollar Rate Margin" means for any day the rate per annum set
       forth below opposite the applicable S&P Bond Rating and Moody's Bond
       Rating in effect on such day:

<TABLE>
<CAPTION>
              Bond Rating                                Eurodollar
           (S&P/Moody's)                   Level         Rate Margin
       ---------------------               -----         -----------
       <S>                                  <C>             <C>
       A/A2 or higher                         I             .175%
       A-/A3                                 II             .190%
       BBB+/Baa1                            III             .200%
       BBB/Baa2                              IV             .225%
       BBB-/Baa3                              V             .350%
       BB+/Ba1 or lower                      VI             .450%;
</TABLE>

       provided that if the ratings of such rating agencies do not fall within
       the same Level, the Eurodollar Rate Margin applicable to such day will
       be the lower Eurodollar Rate Margin and provided, further, that in the
       event a rating is not available from a rating agency, such rating agency
       will be deemed to have assigned its lowest rating.

              "Eurodollar Reserve Percentage" for any Lender for any Interest
       Period for any Eurodollar Rate Advance means the reserve percentage
       applicable during such Interest Period under regulations issued from
       time to time by the Board of Governors of the Federal Reserve System (or
       if more than one such percentage shall be so applicable, the daily
       average of such percentages for those days in such Interest Period
       during which any such percentage shall be so applicable) for determining
       the maximum reserve requirement (including, but not limited to, any
       emergency, supplemental or other marginal reserve requirement) for such
       Lender with respect to liabilities or assets consisting of or including
<PAGE>   13
                                                                               8



       Eurocurrency Liabilities having a term equal to such Interest Period.

              "Events of Default" has the meaning assigned to such term in
       Section 7.1.

              "Excluded Acquisition Debt" means (a) Debt, Guaranties or
       reimbursement obligations of any corporation acquired by the Company or
       any of its Subsidiaries and which Debt, Guaranties or reimbursement
       obligations exist immediately prior to such acquisition (provided that
       (i) such Debt, Guaranties or reimbursement obligations are not incurred
       solely in anticipation of such acquisition and (ii) immediately prior to
       such acquisition such corporation is not a Subsidiary of the Company)
       (b) Debt, Guaranties or reimbursement obligations of Tennessee and its
       Subsidiaries in existence on the date of the Merger and not prohibited
       by the Tennessee Facility, or incurred at any time under the Tennessee
       Facility or (c) Debt, Guaranties or reimbursement obligations in respect
       of any asset acquired by the Company or any of its Subsidiaries and
       which Debt, Guaranties or reimbursement obligations exists immediately
       prior to such acquisition (provided that (i) such Debt, Guaranties or
       reimbursement obligations are not incurred solely in anticipation of
       such acquisition and (ii) immediately prior to such acquisition such
       asset is not an asset of the Company or any of its Subsidiaries).

              "Existing Facilities" has the meaning assigned to such term in
       Section 3.2.

              "Facility Fee Commencement Date"  means the date hereof.

              "FERC" means the Federal Energy Regulatory Commission, or any
       agency or authority of the United States from time to time succeeding to
       its function.

              "Fixed Rate CAF Advance" means any CAF Advance made pursuant to a
       Fixed Rate CAF Advance Request.

              "Fixed Rate CAF Advance Request" means any CAF Advance Request
       requesting the CAF Advance Lenders to offer to make CAF Advances at a
       fixed rate (as opposed to a rate composed of the Applicable LIBO Rate
       plus (or minus) a margin).

              "Guaranty", "Guaranteed" and "Guaranteeing" each means any act by
       which any Person assumes, guarantees, endorses or otherwise incurs
       direct or contingent liability in connection with, or agrees to purchase
       or otherwise acquire or otherwise assures a creditor against loss in
       respect of, any Debt or Project Financing of any Person other than the
       Company or any of its consolidated Subsidiaries (excluding (a) any
       liability by endorsement of negotiable instruments
<PAGE>   14
                                                                               9



       for deposit or collection or similar transactions in the ordinary course
       of business, (b) any liability in connection with obligations of the
       Company, any of its consolidated Subsidiaries or any Restricted
       Affiliate, including, without limitation, obligations under any
       conditional sales agreement, equipment trust financing or equipment
       lease and any liability of any Restricted Affiliate in respect of
       obligations of EPNGC or its consolidated Subsidiaries and (c) any such
       act in connection with a Project Financing that either (i) guarantees
       performance of the completion of the project which is financed by such
       Project Financing, until such time, if any, that such guaranty becomes a
       guaranty of payment of such Project Financing (other than a guaranty of
       payment of the type referred to in subclause (ii) below) or (ii) is
       contingent upon, or the obligation to pay or perform under which is
       contingent upon, the occurrence of any event other than or in addition
       to the passage of time or any Project Financing becoming due (any such
       act referred to in this clause (c) being a "Contingent Guaranty");
       provided, however, that for purposes of this definition the liability of
       the Company or any of its Subsidiaries with respect to any obligation as
       to which a third party or parties are jointly, or jointly and severally,
       liable as a guarantor or otherwise as contemplated hereby and have not
       defaulted on its or their portions thereof, shall be only its pro rata
       portion of such obligation.

              "Holding" means any domestic parent holding company of both EPNGC
       and Tennessee which directly or indirectly owns 100% of the common stock
       of EPNGC and 100% of the common stock of Tennessee; provided, however,
       that immediately after Holding becomes EPNGC's and Tennessee's parent
       holding company, not less than 80% of the shareholders of common stock
       of Holding are the same shareholders of common stock of EPNGC
       immediately prior to Holding becoming EPNGC's and Tennessee's parent
       holding company.

              "Holding Guarantee" has the meaning assigned to such term in
       Section 5.1(g).

              "Indebtedness" of any Person means, without duplication (a)
       indebtedness of such Person for borrowed money, (b) obligations of such
       Person (other than any portion of any trade payable obligation of such
       Person which shall not have remained unpaid for 91 days or more from the
       original due date of such portion) to pay the deferred purchase price of
       property or services, and (c) obligations of such Person as lessee under
       leases which shall have been or should be, in accordance with generally
       accepted accounting principles, recorded as capital leases, except that
       where such indebtedness or obligation of such Person is made jointly, or
       jointly and severally, with any third party or parties other than any
       consolidated Subsidiary of such Person, the amount thereof for the
       purposes of this definition only
<PAGE>   15
                                                                              10



       shall be the pro rata portion thereof payable by such Person, so long as
       such third party or parties have not defaulted on its or their joint and
       several portions thereof.

              "Indemnified Party" means any or all of the Lenders, the
       Administrative Agent and the CAF Advance Agent.

              "Interest Period" means, for each Eurodollar Rate Advance
       comprising part of the same Borrowing, the period beginning on the date
       of such Advance or the date of the Conversion of any Advance into such
       an Advance and ending on the last day of the period selected by the
       applicable Borrower pursuant to the provisions below and, thereafter,
       each subsequent period commencing on the last day of the immediately
       preceding Interest Period and ending on the last day of the period
       selected by the applicable Borrower pursuant to the provisions below.
       The duration of each such Interest Period shall be one, two, three or
       six months, or, subject to availability to each Lender, nine or twelve
       months, in each case as the applicable Borrower may, upon notice
       received by the Administrative Agent not later than 12:00 noon (New York
       City time) on the third Business Day prior to the first day of such
       Interest Period with respect to Eurodollar Rate Advances, select;
       provided, however, that:

                         (a)  the duration of any Interest Period which
              commences before the Termination Date and would otherwise end
              after the Termination Date shall end on the Termination Date;

                         (b)  if the last day of such Interest Period would
              otherwise occur on a day which is not a Business Day, such last
              day shall be extended to the next succeeding Business Day, except
              if such extension would cause such last day to occur in a new
              calendar month, then such last day shall occur on the next
              preceding Business Day; and

                         (c)  Interest Periods commencing on the same date for
              Advances comprising the same Borrowing shall be of the same
              duration.

              "Joinder Agreement" means a Joinder Agreement, substantially in
       the form of Exhibit J hereto, duly executed and delivered by the Company
       and the Borrowing Subsidiary party thereto or Holding, as the case may
       be.

              "Joint Proxy Statement" means the Registration Statements on Form
       S-4, each relating to the Transaction, initially filed by each of EPNGC
       and Tennessee with the SEC on August 27, 1996, as amended through the
       Effective Date.
<PAGE>   16
                                                                              11



              "Lenders" has the meaning assigned to such term in the preamble
       hereof.

              "LIBO Rate CAF Advance" means any CAF Advance made pursuant to a
       LIBO Rate CAF Advance Request.

              "LIBO Rate CAF Advance Request" means any CAF Advance Request
       requesting the CAF Advance Lenders to offer to make CAF Advances at an
       interest rate equal to the Applicable LIBO Rate plus (or minus) a
       margin.

              "Lien" means any lien, security interest or other charge or
       encumbrance, or any assignment of the right to receive income, or any
       other type of preferential arrangement, in each case to secure any
       Indebtedness or any Guaranty of any Person.

              "Majority Lenders" means Lenders the Commitment Percentages of
       which aggregate at least 51%.

              "Margin Stock" means "margin stock" as defined in Regulation U of
       the Board of Governors of the Federal Reserve System, as in effect from
       time to time.

              "Material Adverse Effect" means a material adverse effect on the
       financial condition or operations of the Company and its consolidated
       Subsidiaries on a consolidated basis.

              "Material Subsidiary" means any Subsidiary of Holding (other than
       a Project Financing Subsidiary) that itself (on an unconsolidated,
       stand-alone basis) owns in excess of 10% of the consolidated net
       property, plant and equipment of Holding and its consolidated
       Subsidiaries.

              "Merger" means the merger of Tennessee with a de novo subsidiary
       of EPNGC following the Spin-offs pursuant to the terms of the Merger
       Agreement.

              "Merger Agreement" means the Agreement and Plan of Merger, dated
       as of June 19, 1996, among EPNGC, El Paso Merger Company and Tennessee,
       as amended, supplemented or otherwise modified through the Effective
       Date.

              "Mojave" means Mojave Pipeline Company.

              "Moody's Bond Rating" means, subject to Section 2.11(a)(ii), (a)
       for any day prior to the Ratings Change Date, the rating of EPNGC's
       senior long-term unsecured debt by Moody's Investors Service, Inc. in
       effect at 11:00 A.M., New York City time, on such day and (b) for any
       day that is on or after the Ratings Change Date, the rating of Holding's
       senior long-term unsecured debt by Moody's Investors
<PAGE>   17
                                                                              12



       Service, Inc. in effect at 11:00 A.M., New York City time, on such day.

              "Multiemployer Plan" means a "multiemployer plan" as defined in
       Section 4001(a)(3) of ERISA to which the Company or any ERISA Affiliate
       is making or accruing an obligation to make contributions, or has within
       any of the preceding five plan years made or accrued an obligation to
       make contributions and in respect of which the Company or an ERISA
       Affiliate has any liability (contingent or otherwise), such plan being
       maintained pursuant to one or more collective bargaining agreements.

              "Multiple Employer Plan" means a single employer plan, as defined
       in Section 4001(a)(15) of ERISA, which (a) is maintained for employees
       of the Company or an ERISA Affiliate and at least one Person other than
       the Company and its ERISA Affiliates or (b) was so maintained and in
       respect of which the Company or an ERISA Affiliate could have liability
       under Section 4064 or 4069 of ERISA in the event such plan has been or
       were to be terminated.

              "Net Worth" means with respect to the Company, as of any date of
       determination, the sum of the preferred stock and stockholders' equity
       of the Company as shown on the most recent consolidated balance sheet of
       the Company delivered pursuant to Section 5.3.

              "New Preferred Stock" means the voting junior preferred stock to
       be issued by Tennessee in connection with the Debt Realignment Plan.

              "Note" has the meaning assigned to such term in Section 2.3(d).

              "Notice of Borrowing" has the meaning specified in Section
       2.2(a).

              "Obligations" means the collective reference to the unpaid
       principal of and interest on the Advances and the Notes and all other
       financial liabilities of the Borrowers to the Administrative Agent, the
       CAF Advance Agent and the Lenders (including, without limitation,
       interest accruing at the then applicable rate provided in this Agreement
       after the maturity of the Advances and interest accruing at the then
       applicable rate provided in this Agreement after the filing of any
       petition in bankruptcy, or the commencement of any insolvency,
       reorganization or like proceeding, relating to any Borrower whether or
       not a claim for post-filing or post-petition interest is allowed in such
       proceeding), whether direct or indirect, absolute or contingent, due or
       to become due, or now existing or hereafter incurred, which may arise
       under, out of, or in connection with, this Agreement or the Notes, in
       each case whether on account of
<PAGE>   18
                                                                              13



       principal, interest, reimbursement obligations, fees, indemnities,
       costs, expenses or otherwise (including, without limitation, all fees
       and disbursements of counsel to the Administrative Agent, the CAF
       Advance Agent or to the Lenders that are required to be paid by any
       Borrower pursuant to this Agreement).

              "Other Taxes" has the meaning assigned to such term in Section
       2.20(b).

              "Party" has the meaning assigned to such term in Section 9.8.

              "PBGC" means the Pension Benefit Guaranty Corporation (or any
       successor).

              "Permitted Claims" has the meaning assigned to such term in
       Section 9.9(a).

              "Person" means an individual, partnership, corporation (including
       a business trust), joint stock company, trust, unincorporated
       association, joint venture or other entity, or a country or any
       political subdivision thereof or any agency or instrumentality of such
       country or subdivision.

              "Plan" means a Single Employer Plan or a Multiple Employer Plan.

              "Prime Rate" means the rate of interest per annum publicly
       announced from time to time by Chase as its prime rate in effect at its
       principal office in New York City.  The Prime Rate is not intended to be
       the lowest rate of interest charged by Chase in connection with
       extensions of credit to debtors.

              "Principal Subsidiary" means, at any time, any Subsidiary of the
       Company (other than a Project Financing Subsidiary) having assets at
       such time greater than or equal to 5% of the consolidated assets of the
       Company and its consolidated Subsidiaries at such time.

              "Process Agent" has the meaning specified in Section 9.9(a).

              "Project Financing" means any Indebtedness incurred to finance a
       project, other than any portion of such Indebtedness permitting or
       providing for recourse against the Company or any of its Subsidiaries
       (or for purposes of Section 5.2(a) only, any Restricted Affiliate) other
       than (a) recourse to the stock or assets of the Project Financing
       Subsidiary, if any, incurring or Guaranteeing such Indebtedness, and (b)
       such recourse as exists under any Contingent Guaranty.
<PAGE>   19
                                                                              14



              "Project Financing Subsidiary" means any Subsidiary of the
       Company (or for purposes of Section 5.2(a) only, any Restricted
       Affiliate) whose principal purpose is to incur Project Financing, or to
       become a partner, member or other equity participant in a partnership,
       limited liability company or other entity so created, and substantially
       all the assets of which Subsidiary, partnership limited liability
       company or other entity are limited to those assets being financed (or
       to be financed) in whole or in part by a Project Financing.

              "Ratings Change Date" means the earliest to occur of (a) the date
       on which Holding becomes a Borrower hereunder, (b) the date on which
       Holding becomes a "Borrower" under the $250,000,000 Revolving Credit and
       Competitive Advance Facility Agreement, dated as of the date hereof,
       among EPNGC, the lenders parties thereto and Chase, as administrative
       agent and CAF advance agent, and (c) the date on which Holding becomes a
       "Borrower" under the Tennessee Facility.

              "Receivables Purchase and Sale Agreement" means the Receivables
       Purchase and Sale Agreement dated as of January 14, 1992 among EPNGC,
       CIESCO L.P., a New York limited partnership, Corporate Asset Funding
       Company, a Delaware corporation and Citicorp North America, Inc., as
       agent, as such Agreement may be amended, supplemented, restated or
       otherwise modified from time to time which amendment, supplement,
       restatement or modification will not extend the purchase of receivables
       and other assets thereunder to receivables and assets other than present
       and future gas purchase contract take-or-pay buyout and buydown
       receivables, the collateral and other support therefor and the
       collections therefrom.

              "Reference Lenders" means Chase, Morgan Guaranty Trust Company of
       New York and Union Bank of Switzerland.

              "Register" has the meaning specified in Section 9.7(c).

              "Restricted Affiliate" means any Affiliate of EPNGC (other than a
       Subsidiary of EPNGC) designated by EPNGC as a "Restricted Affiliate" by
       written notice to the Administrative Agent; provided that such Affiliate
       shall not become a Restricted Affiliate until such time that (a) such
       Affiliate executes and delivers a guaranty (in form and substance
       reasonably satisfactory to the Administrative Agent) (each a "Restricted
       Affiliate Guaranty") in favor of the Administrative Agent, for the
       ratable benefit of the Lenders, guaranteeing the prompt and complete
       payment by each Borrower when due (whether at the stated maturity, by
       acceleration or otherwise) of the Obligations owing by such Borrower and
       (b) the Administrative Agent receives legal opinions from the General
       Counsel or Associate General
<PAGE>   20
                                                                              15



       Counsel of Holding and from New York counsel to Holding reasonably
       acceptable to the Administrative Agent, which legal opinions shall be in
       form and substance satisfactory to the Administrative Agent; provided,
       further, that after such time as such Affiliate becomes a Restricted
       Affiliate, EPNGC may terminate the designation of such Affiliate as a
       Restricted Affiliate by written notice to the Administrative Agent at
       which time the aforementioned guaranty of such Affiliate shall also
       terminate.

              "Restricted Affiliate Guaranty" has the meaning assigned to such
       term in the definition of Restricted Affiliate.

              "Revolving Credit Advances" has the meaning assigned to such term
       in Section 2.1.

              "S&P Bond Rating" means, subject to Section 2.11(a)(ii), (a) for
       any day prior to the Ratings Change Date, the rating of EPNGC's senior
       long-term unsecured debt by Standard & Poor's Ratings Group in effect at
       11:00 A.M., New York City time, on such day and (b) for any day that is
       on or after the Ratings Change Date, the rating of Holding's senior
       long-term unsecured debt by Standard & Poor's Ratings Group in effect at
       11:00 A.M., New York City time, on such day.

              "Single Employer Plan" means a single employer plan, as defined
       in Section 4001(a)(15) of ERISA, that (a) is maintained for employees of
       the Company or an ERISA Affiliate and no Person other than the Company
       and its ERISA Affiliates or (b) was so maintained and in respect of
       which the Company or an ERISA Affiliate could have liability under
       Section 4069 of ERISA in the event such plan has been or were to be
       terminated.

              "Spin-offs" means the spin-off of Tennessee's shipbuilding,
       packaging, automotive and administrative services units to its
       shareholders immediately prior to the Merger as described in the Joint
       Proxy Statement.

              "Stated Termination Date" means November 3, 2001.

              "Subsidiary" means, as to any Person, any corporation of which at
       least a majority of the outstanding stock having by the terms thereof
       ordinary voting power to elect a majority of the board of directors of
       such corporation (irrespective of whether or not at the time stock of
       any other class or classes of such corporation shall or might have
       voting power by reason of the happening of any contingency) is at the
       time directly or indirectly beneficially owned or controlled by such
       Person or one or more of its Subsidiaries or such Person and one or more
       of the Subsidiaries of such Person.
<PAGE>   21
                                                                              16




              "Taxes" has the meaning assigned to such term in Section 2.20(a).

              "Tenneco Energy" means all energy businesses and operations owned
       directly or indirectly by Tennessee and other operations of Tennessee
       and its Subsidiaries other than those relating to Tennessee's
       automotive, packaging, administrative services and shipbuilding
       businesses.

              "Tennessee" means Tenneco Inc., a Delaware corporation, which is
       to be renamed El Paso Tennessee Pipeline Co. after the Merger, and its
       successors.

              "Tennessee Facility" means the $3,000,000,000 Revolving Credit
       and Competitive Advance Facility Agreement, dated as of November 4,
       1996, among Tennessee, the several financial institutions from time to
       time parties thereto, and The Chase Manhattan Bank, as administrative
       agent and CAF advance agent thereunder, as the same may be amended,
       modified or supplemented from time to time.

              "Termination Date" means the earlier of (a) the Stated
       Termination Date and (b) the date of termination in whole of the
       Commitments pursuant to Section 2.9 or 7.1.

              "Termination Event" means (a) a "reportable event," as such term
       is described in Section 4043 of ERISA (other than a "reportable event"
       not subject to the provision for 30-day notice to the PBGC under
       subsection .11, .12, .13, .14, .16, .18, .19 or .20 of PBGC Reg. Section
       2615), or an event described in Section 4062(e) of ERISA, or (b) the
       withdrawal of the Company or any ERISA Affiliate from a Multiple
       Employer Plan during a plan year in which it was a "substantial
       employer," as such term is defined in Section 4001(a)(2) of ERISA or the
       incurrence of liability by the Company or any ERISA Affiliate under
       Section 4064 of ERISA upon the termination of a Multiple Employer Plan,
       or (c) the filing of a notice of intent to terminate a Plan or the
       treatment of a Plan amendment as a termination under Section 4041 of
       ERISA, or (d) the institution of proceedings to terminate a Plan by the
       PBGC under Section 4042 of ERISA, or (e) the conditions set forth in
       Section 302(f)(1)(A) and (B) of ERISA to the creation of a lien upon
       property or rights to property of the Company or any ERISA Affiliate for
       failure to make a required payment to a Plan are satisfied, or (f) the
       adoption of an amendment to a Plan requiring the provision of security
       to such Plan, pursuant to Section 307 of ERISA, or (g) the occurrence of
       any other event or the existence of any other condition which would
       reasonably be expected to result in the termination of, or the
       appointment of a trustee to administer, any Plan under Section 4042 of
       ERISA.

              "Three-Month Secondary CD Rate" means, for any day, the secondary
       market rate (adjusted to the basis of a year of
<PAGE>   22
                                                                              17



       365 or 366 days, as the case may be) for three-month certificates of
       deposit reported as being in effect on such day (or, if such day shall
       not be a Business Day, the next preceding Business Day) by the Board of
       Governors of the Federal Reserve System (the "Board") through the public
       information telephone line of the Federal Reserve Bank of New York
       (which rate will, under the current practices of the Board, be published
       in Federal Reserve Statistical Release H.15(519) during the week
       following such day), or, if such rate shall not be so reported on such
       day or such next preceding Business Day, the average of the secondary
       market quotations for three-month certificates of deposit of major money
       center banks in New York City received at approximately 10:00 A.M., New
       York City time, on such day (or, if such day shall not be a Business
       Day, on the next preceding Business Day) by the Administrative Agent
       from three New York City negotiable certificate of deposit dealers of
       recognized standing selected by it.

              "Transaction" means the Merger, the Spin-offs, the Debt
       Realignment Plan, and the issuance of the New Preferred Stock.

              "Type" means (a) as to any Revolving Credit Advance, its nature
       as a Base Rate Advance or a Eurodollar Rate Advance and (b) as to any
       CAF Advance, its nature as a Fixed Rate CAF Advance or a LIBO Rate CAF
       Advance.

              "Withdrawal Liability" has the meaning given such term under Part
       1 of Subtitle E of Title IV of ERISA.

              SECTION 1.2  Computation of Time Periods.  Unless otherwise
stated in this Agreement, in the computation of a period of time from a
specified date to a later specified date, the word "from" means "from and
including" and the words "to" and "until" each means "to but excluding."

              SECTION 1.3  Accounting Terms.  All accounting terms not
specifically defined herein shall be construed in accordance with generally
accepted accounting principles either (a) consistent with those principles
applied in the preparation of the financial statements referred to in Section
4.1(e) or (b) not materially inconsistent with such principles (so that no
covenant contained in Section 5.1 or 5.2 would be calculated or construed in a
materially different manner or with materially different results than if such
covenant were calculated or construed in accordance with clause (a) of this
Section 1.3).

              SECTION 1.4  References.  The words "hereof", "herein" and
"hereunder" and words of similar import when used in this Agreement shall refer
to this Agreement as a whole and not to any particular provision of this
Agreement, and Article, Section, Schedule and Exhibit references are to this
Agreement unless otherwise specified.
<PAGE>   23
                                                                              18





                                   ARTICLE II

                       AMOUNTS AND TERMS OF THE ADVANCES

              SECTION 2.1  The Revolving Credit Advances.  Each Lender
severally agrees, on the terms and conditions hereinafter set forth, to make
revolving credit advances ("Revolving Credit Advances") to the Borrowers or any
one or more of them from time to time on any Business Day during the period
from the date hereof to and including the Termination Date in an aggregate
amount not to exceed at any time outstanding the amount of such Lender's
Commitment; provided that the aggregate amount of the Advances (other than
Advances of Objecting Lenders) outstanding shall not at any time exceed the
aggregate amount of the Commitments.  Each Borrowing shall be in an aggregate
amount of $5,000,000 in the case of a Borrowing comprised of Base Rate Advances
and $20,000,000 in the case of a Borrowing comprised of Eurodollar Rate
Advances, or, in each case, an integral multiple of $1,000,000 in excess
thereof (or, in the case of a Borrowing of Base Rate Advances, the aggregate
unused Commitments, if less) and shall consist of Revolving Credit Advances of
the same Type made on the same day by the Lenders ratably according to their
respective Commitments.  Within the limits of each Lender's Commitment, any
Borrower may make more than one Borrowing on any Business Day and may borrow,
repay pursuant to Section 2.10 or prepay pursuant to Section 2.15, and reborrow
under this Section 2.1.

              SECTION 2.2  Making the Revolving Credit Advances.  (a) Each
Borrowing of Revolving Credit Advances shall be made on notice by the Company
to the Administrative Agent (a "Notice of Borrowing") received by the
Administrative Agent, (i) in the case of a proposed Borrowing comprised of Base
Rate Advances, not later than 10:00 A.M. (New York City time) on the Business
Day of such proposed Borrowing and (ii) in the case of a proposed Borrowing
comprised of Eurodollar Rate Advances, not later than 12:00 noon (New York City
time) on the third Business Day prior to the date of such proposed Borrowing.
Each Notice of Borrowing shall be by telecopy or telephone (and if by
telephone, confirmed promptly by telecopier), in substantially the form of
Exhibit B, specifying therein the requested (A) Borrower, (B) date of such
Borrowing, (C) Type of Revolving Credit Advances comprising such Borrowing, (D)
aggregate amount of such Borrowing, and (E) in the case of a Borrowing
comprised of Eurodollar Rate Advances, the initial Interest Period for each
such Advance.  Each Lender shall, before 1:00 P.M. (New York City time) on the
date of such Borrowing, make available to the Administrative Agent at its
address at 270 Park Avenue, New York, New York, 10017, Reference:  El Paso
Natural Gas Company, or at such other address designated by notice from the
Administrative Agent to the Lenders pursuant to Section 9.2, in same day funds,
such Lender's ratable portion of such Borrowing.  Immediately after the
Administrative Agent's receipt of such funds and upon fulfillment of the
applicable
<PAGE>   24
                                                                              19



conditions set forth in Article III, the Administrative Agent will make such
funds available to the applicable Borrower at Chase, 270 Park Avenue, New York,
New York, 10017, Account No. 323291503, Reference:  El Paso Natural Gas
Company, or at such other account of the applicable Borrower maintained by the
Administrative Agent (or any successor Administrative Agent) designated by the
applicable Borrower and agreed to by the Administrative Agent (or such
successor Administrative Agent), in same day funds.

              (b)    Each Notice of Borrowing shall be irrevocable and binding
on the applicable Borrower.  In the case of any Borrowing which the related
Notice of Borrowing specified is to be comprised of Eurodollar Rate Advances,
if such Advances are not made as a result of any failure to fulfill on or
before the date specified for such Borrowing the applicable conditions set
forth in Article III, the applicable Borrower shall indemnify each Lender
against any loss, cost or expense incurred by such Lender as a result of such
failure, including, without limitation, any loss, cost or expense incurred by
reason of the liquidation or reemployment of deposits or other funds acquired
by such Lender to fund the Advance to be made by such Lender as part of such
Borrowing.

              (c)    Unless the Administrative Agent shall have received notice
from a Lender prior to the date of any Borrowing that such Lender will not make
available to the Administrative Agent such Lender's ratable portion of such
Borrowing, the Administrative Agent may assume that such Lender has made such
portion available to the Administrative Agent on the date of such Borrowing in
accordance with subsection (a) of this Section 2.2 and the Administrative Agent
may, in reliance upon such assumption, make available to the applicable
Borrower on such date a corresponding amount.  If and to the extent such Lender
shall not have so made such ratable portion available to the Administrative
Agent, such Lender and the applicable Borrower severally agree to repay to the
Administrative Agent forthwith on demand such corresponding amount together
with interest thereon, for each day from the date such amount is made available
to the applicable Borrower until the date such amount is repaid to the
Administrative Agent, at the Effective Federal Funds Rate for such day.  If
such Lender shall repay to the Administrative Agent such corresponding amount,
such amount so repaid shall constitute such Lender's Advance to the applicable
Borrower as part of such Borrowing for purposes of this Agreement.

              (d)    The failure of any Lender to make the Advance to be made
by it as part of any Borrowing shall not relieve any other Lender of its
obligation, if any, hereunder to make its Advance on the date of such
Borrowing, but no Lender shall be responsible for the failure of any other
Lender to make the Advance to be made by such other Lender on the date of any
Borrowing.
<PAGE>   25
                                                                              20



              SECTION 2.3  Evidence of Debt.  (a)  Each Lender shall maintain
in accordance with its usual practice an account or accounts evidencing
indebtedness of each Borrower to such Lender resulting from each Revolving
Credit Advance of such Lender to such Borrower from time to time, including the
amounts of principal and interest payable and paid to such Lender from time to
time in respect of such Revolving Credit Advance.

              (b)    The Administrative Agent shall maintain the Register
pursuant to Section 9.7(c), and a subaccount therein for each Lender, in which
shall be recorded (i) the amount of each Revolving Credit Advance made
hereunder, the Type thereof and each Interest Period applicable thereto, (ii)
the amount of any principal or interest due and payable or to become due and
payable from each Borrower on account of such Revolving Credit Advance to each
Lender hereunder and (iii) both the amount of any sum received by the
Administrative Agent hereunder from each Borrower and each Lender's share
thereof.

              (c)    The entries made in the Register and the accounts of each
Lender maintained pursuant to Section 2.3(a) shall, to the extent permitted by
applicable law, be prima facie evidence of the existence and amounts of the
obligations of each Borrower therein recorded; provided, however, that the
failure of any Lender or the Administrative Agent to maintain the Register or
any such account, or any error therein, shall not in any manner affect the
obligation of each Borrower to repay (with applicable interest) the Revolving
Credit Advances made to each such Borrower by such Lender in accordance with
the terms of this Agreement.

              (d)    Each Borrower agrees that, upon the request to the
Administrative Agent by any Lender, such Borrower will execute and deliver to
such Lender a promissory note of such Borrower evidencing the Revolving Credit
Advances of such Lender to such Borrower, substantially in the form of Exhibit
A with appropriate insertions as to date and principal amount (a "Note").

              SECTION 2.4  CAF Advances.  Subject to the terms and conditions
of this Agreement, the Borrowers or any one or more of them may borrow CAF
Advances from time to time during the CAF Advance Availability Period on any
Business Day.  The Company shall, in consultation with the CAF Advance Agent,
designate Lenders from time to time as CAF Advance Lenders by written notice to
the CAF Advance Agent.  The CAF Advance Agent shall transmit each such notice
of designation promptly to each designated CAF Advance Lender.  CAF Advances
shall be borrowed in amounts such that the aggregate amount of Advances
outstanding at any time shall not exceed the aggregate amount of the
Commitments at such time.  Any CAF Advance Lender may make CAF Advances in
amounts which, individually and together with the aggregate amount of other
Advances of such CAF Advance Lender, exceed such CAF Advance Lender's
Commitment, and such CAF Advance Lender's CAF Advances shall not be deemed to
utilize such CAF Advance
<PAGE>   26
                                                                              21



Lender's Commitment.  Within the limits and on the conditions hereinafter set
forth with respect to CAF Advances, the Borrowers from time to time may borrow,
repay and reborrow CAF Advances.

              SECTION 2.5  Procedure for CAF Advance Borrowings.  (a) A
Borrower, or the Company on behalf of a Borrower, shall request CAF Advances by
delivering a CAF Advance Request to the CAF Advance Agent, not later than 12:00
Noon (New York City time) four Business Days prior to the date of the proposed
Borrowing (in the case of a LIBO Rate CAF Advance Request), and not later than
10:00 A.M. (New York City time) one Business Day prior to the date of the
proposed Borrowing (in the case of a Fixed Rate CAF Advance Request).  Each CAF
Advance Request may solicit bids for CAF Advances in an aggregate principal
amount of $10,000,000 or an integral multiple of $1,000,000 in excess thereof
and having not more than five alternative maturity dates.  The maturity date
for each CAF Advance shall be not less than 7 days nor more than 360 days after
the date of the Borrowing therefor (and in any event shall be not later than
the Stated Termination Date); provided that each LIBO Rate CAF Advance shall
mature one, two, three or six months or, if available, nine or twelve months
after the date of the Borrowing therefor.  The CAF Advance Agent shall notify
each CAF Advance Lender promptly by telecopy of the contents of each CAF
Advance Request received by the CAF Advance Agent.

              (b)    In the case of a LIBO Rate CAF Advance Request, upon
receipt of notice from the CAF Advance Agent of the contents of such CAF
Advance Request, each CAF Advance Lender may elect, in its sole discretion, to
offer irrevocably to make one or more CAF Advances at the Applicable LIBO Rate
plus (or minus) a margin determined by such CAF Advance Lender in its sole
discretion for each such CAF Advance.  Any such irrevocable offer shall be made
by delivering a CAF Advance Offer to the CAF Advance Agent, before 10:30 A.M.
(New York City time) on the day that is three Business Days before the date of
the proposed Borrowing, setting forth:

                  (i)  the maximum amount of CAF Advances for each maturity
       date and the aggregate maximum amount of CAF Advances for all maturity
       dates which such CAF Advance Lender would be willing to make (which
       amounts may, subject to Section 2.4, exceed such CAF Advance Lender's
       Commitment); and

                 (ii)  the margin above or below the Applicable LIBO Rate at
       which such CAF Advance Lender is willing to make each such CAF Advance.

The CAF Advance Agent shall advise the Company and the applicable Borrower
before 11:00 A.M. (New York City time) on the date which is three Business Days
before the proposed date of the Borrowing of the contents of each such CAF
Advance Offer received by it.  If the CAF Advance Agent, in its capacity as a
CAF Advance
<PAGE>   27
                                                                              22



Lender, shall elect, in its sole discretion, to make any such CAF Advance
Offer, it shall advise the Company and the applicable Borrower of the contents
of its CAF Advance Offer before 10:15 A.M. (New York City time) on the date
which is three Business Days before the proposed date of the Borrowing.

              (c)    In the case of a Fixed Rate CAF Advance Request, upon
receipt of notice from the CAF Advance Agent of the contents of such CAF
Advance Request, each CAF Advance Lender may elect, in its sole discretion, to
offer irrevocably to make one or more CAF Advances at a rate of interest
determined by such CAF Advance Lender in its sole discretion for each such CAF
Advance.  Any such irrevocable offer shall be made by delivering a CAF Advance
Offer to the CAF Advance Agent before 9:30 A.M. (New York City time) on the
proposed date of the Borrowing, setting forth:

                  (i)  the maximum amount of CAF Advances for each maturity
       date, and the aggregate maximum amount for all maturity dates, which
       such CAF Advance Lender would be willing to make (which amounts may,
       subject to Section 2.4, exceed such CAF Advance Lender's Commitment);
       and

                 (ii)  the rate of interest at which such CAF Advance Lender is
       willing to make each such CAF Advance.

The CAF Advance Agent shall advise the Company and the applicable Borrower
before 10:00 A.M. (New York City time) on the proposed date of the Borrowing of
the contents of each such CAF Advance Offer received by it.  If the CAF Advance
Agent, in its capacity as a CAF Advance Lender, shall elect, in its sole
discretion, to make any such CAF Advance Offer, it shall advise the Company and
the applicable Borrower of the contents of its CAF Advance Offer before 9:15
A.M. (New York City time) on the proposed date of the Borrowing.

              (d)    Before 11:30 A.M. (New York City time) three Business Days
before the proposed date of the Borrowing (in the case of CAF Advances
requested by a LIBO Rate CAF Advance Request) and before 10:30 A.M. (New York
City time) on the proposed date of the Borrowing (in the case of CAF Advances
requested by a Fixed Rate CAF Advance Request), the Company, in its absolute
discretion, shall:

                  (i)  cancel such CAF Advance Request by giving the CAF
       Advance Agent telephone notice to that effect, or

                 (ii)  by giving telephone notice to the CAF Advance Agent
       (immediately confirmed by delivery to the CAF Advance Agent of a CAF
       Advance Confirmation in writing or by telecopy) (A) subject to the
       provisions of Section 2.5(e), accept one or more of the offers made by
       any CAF Advance Lender or CAF Advance Lenders pursuant to Section 2.5(b)
       or Section 2.5(c), as the case may be, of the amount of CAF Advances for
       each relevant maturity date and (B) reject any
<PAGE>   28
                                                                              23



       remaining offers made by CAF Advance Lenders pursuant to Section 2.5(b)
       or Section 2.5(c), as the case may be.

              (e)    The Company's acceptance of CAF Advances in response to
any CAF Advance Request shall be subject to the following limitations:

                  (i)  the amount of CAF Advances accepted for each maturity
       date specified by any CAF Advance Lender in its CAF Advance Offer shall
       not exceed the maximum amount for such maturity date specified in such
       CAF Advance Offer;

                 (ii)  the aggregate amount of CAF Advances accepted for all
       maturity dates specified by any CAF Advance Lender in its CAF Advance
       Offer shall not exceed the aggregate maximum amount specified in such
       CAF Advance Offer for all such maturity dates;

                (iii)  the Company may not accept offers for CAF Advances for
       any maturity date in an aggregate principal amount in excess of the
       maximum principal amount requested in the related CAF Advance Request;
       and

                 (iv)  if the Company accepts any of such offers, it must
       accept offers based solely upon pricing for such relevant maturity date
       and upon no other criteria whatsoever and if two or more CAF Advance
       Lenders submit offers for any maturity date at identical pricing and the
       Company accepts any of such offers but does not wish to (or by reason of
       the limitations set forth in Section 2.4 or in Section 2.5(e)(iii),
       cannot) borrow the total amount offered by such CAF Advance Lenders with
       such identical pricing, the Company shall accept offers from all of such
       CAF Advance Lenders in amounts allocated among them pro rata according
       to the amounts offered by such CAF Advance Lenders (or as nearly pro
       rata as shall be practicable after giving effect to the requirement that
       CAF Advances made by a CAF Advance Lender on a date of the Borrowing for
       each relevant maturity date shall be in a principal amount of $5,000,000
       or an integral multiple of $1,000,000 in excess thereof; provided that
       if the number of CAF Advance Lenders that submit offers for any maturity
       date at identical pricing is such that, after the Company accepts such
       offers pro rata in accordance with the foregoing, the CAF Advance to be
       made by such CAF Advance Lenders would be less than $5,000,000 principal
       amount, the number of such CAF Advance Lenders shall be reduced by the
       CAF Advance Agent by lot until the CAF Advances to be made by such
       remaining CAF Advance Lenders would be in a principal amount of
       $5,000,000 or an integral multiple of $1,000,000 in excess thereof).

              (f)    If the Company notifies the CAF Advance Agent that a CAF
Advance Request is cancelled pursuant to Section 2.5(d)(i),
<PAGE>   29
                                                                              24



the CAF Advance Agent shall give prompt telephone notice thereof to the CAF
Advance Lenders.

              (g)    If the Company accepts pursuant to Section 2.5(d)(ii) one
or more of the offers made by any CAF Advance Lender or CAF Advance Lenders,
the CAF Advance Agent promptly shall notify each CAF Advance Lender which has
made such a CAF Advance Offer of (i) the aggregate amount of such CAF Advances
to be made on such Borrowing Date for each maturity date and (ii) the
acceptance or rejection of any offers to make such CAF Advances made by such
CAF Advance Lender.  Before 1:00 P.M. (New York City time) on the date of the
Borrowing specified in the applicable CAF Advance Request, each CAF Advance
Lender whose CAF Advance Offer has been accepted shall make available to the
Administrative Agent at its office set forth in Section 9.2 the amount of CAF
Advances to be made by such CAF Advance Lender, in same day funds.  The
Administrative Agent will make such funds available to the applicable Borrower
as soon as practicable on such date at the Administrative Agent's aforesaid
address.  As soon as practicable after each Borrowing Date, the CAF Advance
Agent shall notify each Lender of the aggregate amount of CAF Advances advanced
on such Borrowing Date and the respective maturity dates thereof.

              (h)    The failure of any CAF Advance Lender to make the CAF
Advance to be made by it as part of any Borrowing shall not relieve any other
Lender of its obligation, if any, hereunder to make its CAF Advance on the date
of such Borrowing, but no CAF Lender shall be responsible for the failure of
any other CAF Advance Lender to make the CAF Advance to be made by such CAF
Advance Lender on the date of any Borrowing.

              (i)    A CAF Advance Request may request offers for CAF Advances
to be made on not more than one Borrowing Date and to mature on not more than
five CAF Advance Maturity Dates.  No CAF Advance Request may be submitted
earlier than five Business Days after submission of any other CAF Advance
Request.

              SECTION 2.6  CAF Advance Payments.  (a)  The applicable Borrower
shall repay to the Administrative Agent, for the account of each CAF Advance
Lender which has made a CAF Advance to it, on the applicable CAF Advance
Maturity Date the then unpaid principal amount of such CAF Advance.  The
Borrowers shall not have the right to prepay any principal amount of any CAF
Advance.

              (b)    The applicable Borrower shall pay interest on the unpaid
principal amount of each CAF Advance to it from the date of the Borrowing to
the applicable CAF Advance Maturity Date at the rate of interest specified in
the CAF Advance Offer accepted by the applicable Borrower in connection with
such CAF Advance (calculated on the basis of a 360-day year for actual days
elapsed), payable on each applicable CAF Advance Interest Payment Date.
<PAGE>   30
                                                                              25



              (c)    If all or a portion of the principal amount of any CAF
Advance shall not be paid when due (whether at the stated maturity, by
acceleration or otherwise), such overdue principal amount shall, without
limiting any rights of any Lender under this Agreement, bear interest from the
date on which such payment was due at a rate per annum which is 1% above the
rate which would otherwise be applicable pursuant to such CAF Advance until the
stated maturity date of such CAF Advance, and for each day thereafter at a rate
per annum which is 2% above the Base Rate, in each case until paid in full (as
well after as before judgment).  Interest accruing pursuant to this paragraph
(c) shall be payable from time to time on demand.

              SECTION 2.7  Evidence of Debt.  Each Lender shall maintain in
accordance with its usual practice appropriate records evidencing indebtedness
of each Borrower to such Lender resulting from each CAF Advance of such Lender
to such Borrower from time to time, including the amounts of principal and
interest payable and paid to such Lender from time to time in respect of such
CAF Advance.  The Administrative Agent shall maintain the Register pursuant to
Section 9.7(c) and a record therein for each Lender, in which shall be recorded
(i) the amount of each CAF Advance made by such Lender to each Borrower, the
CAF Advance Maturity Date thereof, the interest rate applicable thereto and
each CAF Advance Interest Payment Date applicable thereto, and (ii) the amount
of any sum received by the Administrative Agent hereunder from a Borrower on
account of such CAF Advance.  The entries made in the Register and the records
of each Lender maintained pursuant to this Section 2.7 shall, to the extent
permitted by applicable law, be prima facie evidence of the existence and
amounts of the obligations of each Borrower therein recorded; provided,
however, that the failure of any Lender or the Administrative Agent to maintain
the Register or any such record, or any error therein, shall not in any manner
affect the obligation of each Borrower to repay (with applicable interest) the
CAF Advances made by such Lender in accordance with the terms of this
Agreement.

              SECTION 2.8  Fees.  (a) The Company agrees to pay to the
Administrative Agent for the account of each Lender a facility fee for the
period from and including the Facility Fee Commencement Date until all Advances
have been paid in full and all Commitments have been terminated, computed at a
variable rate per annum on the average daily amount of the greater of (i) the
Commitment of such Lender and (ii) the outstanding principal amount of
Revolving Credit Advances of such Lender during the period for which payment is
made, which rate will vary according to the S&P Bond Rating and the Moody's
Bond Rating as follows:
<PAGE>   31
                                                                              26



<TABLE>
<CAPTION>
            Bond Rating                                  Facility
           (S&P/Moody's)                   Level         Fee Rate
       ---------------------               -----         --------
       <S>                                  <C>           <C>
       A/A2 or higher                         I           .075%
       A-/A3                                 II           .085%
       BBB+/Baa1                            III           .100%
       BBB/Baa2                              IV           .125%
       BBB-/Baa3                              V           .150%
       BB+/Ba1 or lower                      VI           .250%;
</TABLE>

provided that if the ratings of such rating agencies do not fall within the
same Level, the rate applicable to such day will be the lower facility fee rate
and provided, further, that in the event a rating is not available from either
rating agency, such rating agency will be deemed to have assigned its lowest
rating.  Such facility fees shall be payable quarterly in arrears on the last
day of each March, June, September and December and on the Termination Date or
such earlier date on which the Commitments shall terminate as provided herein,
commencing on the first of such dates to occur after the date hereof.

              (b)    The Company agrees to pay to Chase Securities Inc., the
Administrative Agent and the CAF Advance Agent the fees set forth in the
letter, dated September 20, 1996, from Chase Securities Inc. and Chase to
EPNGC.

              SECTION 2.9 Reduction of the Commitments.  The Company shall have
the right, upon at least three Business Days' notice to the Administrative
Agent, to terminate in whole or reduce ratably in part the unused portions of
the respective Commitments of the Lenders, provided that each partial reduction
shall be in the aggregate amount of $10,000,000 or any whole multiple of
$1,000,000 in excess thereof.

              SECTION 2.10  Repayment of Advances.  The Borrowers shall repay
to each Lender on the Termination Date the aggregate principal amount of the
Advances then owing to such Lender.

              SECTION 2.11  Interest on Revolving Credit Advances.  (a)
Ordinary Interest.  The Borrowers shall pay interest on the unpaid principal
amount of each Revolving Credit Advance owing to each Lender from the date of
such Advance until such principal amount is due (whether at stated maturity, by
acceleration or otherwise), at the following rates:

                  (i)  Base Rate Advances.  During such periods as such Advance
       is a Base Rate Advance, a rate per annum equal at all times to the Base
       Rate in effect from time to time, payable quarterly in arrears on the
       last day of each March, June, September and December during such periods
       and on the date such Base Rate Advance shall be Converted or due
       (whether at stated maturity, by acceleration or otherwise).
<PAGE>   32
                                                                              27



                 (ii)  Eurodollar Rate Advances.  During such periods as such
       Advance is a Eurodollar Rate Advance, at a rate per annum equal at all
       times during each Interest Period for such Advance to the sum of the
       Eurodollar Rate for such Interest Period plus the Eurodollar Rate Margin
       (provided that notwithstanding the definitions of Moody's Bond Rating
       and S&P Bond Rating, in the case of Eurodollar Rate Advances to EPNGC
       and its Subsidiaries, whether before, on or after the Ratings Change
       Date, the Eurodollar Rate Margin shall be based on the Moody's Bond
       Rating and S&P Bond Rating of EPNGC, and, in the case of all other
       Borrowers, shall be based on the Moody's Bond Rating and S&P Bond Rating
       of Holding) in effect from time to time, payable on the last day of each
       such Interest Period and, if any such Interest Period has a duration of
       more than three months, on each day which occurs during such Interest
       Period every three months from the first day of such Interest Period,
       and on the date such Advance shall be Converted or due (whether at
       stated maturity, by acceleration or otherwise).

              (b)    Default Interest.  The applicable Borrower shall pay
interest on the unpaid principal amount of each Revolving Credit Advance to it
that is not paid when due (whether at stated maturity, by acceleration or
otherwise) from the date on which such amount is due until such amount is paid
in full, payable on demand, at a rate per annum equal at all times (i) from
such due date to the last day of the then existing Interest Period in the case
of each Eurodollar Rate Advance, to 1% per annum above the interest rate per
annum required to be paid on such Advance immediately prior to the date on
which such amount became due, and (ii) from and after the last day of the then
existing Interest Period, and at all times in the case of any Base Rate
Advance, to 1% per annum above the Base Rate in effect from time to time.

              SECTION 2.12 Additional Interest on Eurodollar Rate Advances.  If
any Lender shall determine in good faith that reserves under regulations of the
Board of Governors of the Federal Reserve System are required to be maintained
by it in respect of, or a portion of its costs of maintaining reserves under
such regulations is properly attributable to, one or more of its Eurodollar
Rate Advances, the applicable Borrower shall pay to such Lender additional
interest on the unpaid principal amount of each such Eurodollar Rate Advance to
it (other than any such additional interest accruing to a particular Lender in
respect of periods prior to the 30th day preceding the date notice of such
interest is given by such Lender as provided in this Section 2.12), payable on
the same day or days on which interest is payable on such Advance, at an
interest rate per annum equal at all times during each Interest Period for such
Advance to the excess of (i) the rate obtained by dividing the Eurodollar Rate
for such Interest Period by a percentage equal to 100% minus the Eurodollar
Reserve Percentage, if any, for such Lender for such Interest Period over (ii)
the Eurodollar Rate for
<PAGE>   33
                                                                              28



such Interest Period.  The amount of such additional interest (if any) shall be
determined by each Lender, and such Lender shall furnish written notice of the
amount of such additional interest to the Company and the Administrative Agent,
which notice shall be conclusive and binding for all purposes, absent manifest
error.

              SECTION 2.13 Interest Rate Determination.  (a)  Each Reference
Lender agrees to furnish to the Administrative Agent timely information for the
purpose of determining the Eurodollar Rate.  If any one or more of the
Reference Lenders shall not furnish such timely information to the
Administrative Agent for the purpose of determining any such interest rate, the
Administrative Agent shall determine such interest rate on the basis of timely
information furnished by the remaining Reference Lenders.

              (b)    The Administrative Agent shall give prompt notice to the
Company and the Lenders of the applicable interest rate determined by the
Administrative Agent for purposes of Section 2.11(a)(i) or (ii), and the
applicable rate, if any, furnished by each Reference Lender for the purpose of
determining the applicable interest rate under Section 2.11(a)(ii).

              (c)    If fewer than two Reference Lenders furnish timely
information to the Administrative Agent for determining the Eurodollar Rate for
any Eurodollar Rate Advances,

                  (i)  the Administrative Agent shall give the Company and each
       Lender prompt notice thereof by telephone (confirmed in writing) that
       the interest rate cannot be determined for such Eurodollar Rate
       Advances,

                 (ii)  each such Advance will automatically, on the last day of
       the then existing Interest Period therefor, Convert into a Base Rate
       Advance (or if such Advance is then a Base Rate Advance, will continue
       as a Base Rate Advance), and

                (iii)  the obligations of the Lenders to make, or to Convert
       Advances into, Eurodollar Rate Advances shall be suspended until the
       Administrative Agent shall notify the Company and the Lenders that the
       circumstances causing such suspension no longer exist.

              (d)    If, with respect to any Eurodollar Rate Advances, the
Majority Lenders determine and give notice to the Administrative Agent that, as
a result of conditions in or generally affecting the London interbank
eurodollar market, the rates of interest determined on the basis of the
Eurodollar Rate for any Interest Period for such Advances will not adequately
reflect the cost to such Majority Lenders of making, funding or maintaining
their respective Eurodollar Rate Advances for such
<PAGE>   34
                                                                              29



Interest Period, the Administrative Agent shall forthwith so notify the Company
and the Lenders, whereupon,

                  (i)  each such Advance will automatically, on the last day of
       the then existing Interest Period therefor, Convert into a Base Rate
       Advance, and

                 (ii)  the obligation of the Lenders to make, or to Convert
       Advances into, Eurodollar Rate Advances shall be suspended until the
       Administrative Agent shall notify the Company and the Lenders that the
       circumstances causing such suspension no longer exist.

              (e)    If the applicable Borrower shall fail to select the
duration of any Interest Period for any Eurodollar Rate Advances in accordance
with the provisions contained in the definition of "Interest Period" in Section
1.1, the Administrative Agent will forthwith so notify the applicable Borrower
and the Lenders and such Advances will automatically, on the last day of the
then existing Interest Period therefor, Convert into Base Rate Advances.

              (f)    On the date on which the aggregate unpaid principal amount
of Eurodollar Rate Advances comprising any Borrowing shall be reduced, by
payment or prepayment or otherwise, to less than $10,000,000, such Eurodollar
Rate Advances shall automatically Convert into Base Rate Advances, and on and
after such date the right of the applicable Borrower to Convert such Advances
into Eurodollar Rate Advances shall terminate; provided, however, that if and
so long as each such Eurodollar Rate Advance shall have the same Interest
Period as Eurodollar Rate Advances comprising another Borrowing or other
Borrowings, and the aggregate unpaid principal amount of all such Eurodollar
Rate Advances shall equal or exceed $20,000,000, the applicable Borrower shall
have the right to continue all such Advances as, or to Convert all such
Advances into Eurodollar Rate Advances having the same Interest Period.

              (g)    If any Reference Lender shall for any reason no longer
have a Commitment or any Revolving Credit Advances, such Reference Lender shall
thereupon cease to be a Reference Lender, and if, as a result, there shall only
be one Reference Lender remaining, the Administrative Agent (after consultation
with the Company and the Lenders) shall, by notice to the Company and the
Lenders, designate another Lender as a Reference Lender so that there shall at
all times be at least two Reference Lenders.

              SECTION 2.14  Voluntary Conversion of Advances.  Any Borrower may
on any Business Day, upon notice given to the Administrative Agent, not later
than 10:00 A.M. (New York City time) on the Business Day of the proposed
Conversion of Eurodollar Rate Advances to Base Rate Advances and not later than
12:00 noon (New York City time) on the third Business Day prior to the date of
the proposed Conversion in the case of a
<PAGE>   35
                                                                              30



Conversion of Base Rate Advances to Eurodollar Rate Advances, and subject to
the provisions of Sections 2.13, 2.16 and 2.18, Convert all Advances of one
Type comprising the same Borrowing into Advances of another Type; provided,
however, that any Conversion of any Eurodollar Rate Advances into Base Rate
Advances made on any day other than the last day of an Interest Period for such
Eurodollar Rate Advances shall be subject to the provisions of Section 9.4(b)
and provided, further, that no Revolving Credit Advance may be converted into a
Eurodollar Rate Advance if an Event of Default has occurred and is continuing.
Each such notice of a Conversion shall, within the restrictions specified
above, specify (a) the date of such Conversion, (b) the Advances to be
Converted, and (c) if such Conversion is into Eurodollar Rate Advances, the
duration of the Interest Period for each such Advance.

              SECTION 2.15  Optional and Mandatory Prepayments.  (a)  Optional
Prepayments.  Any Borrower may upon (i) in the case of Eurodollar Rate
Advances, at least two Business Days' notice and (ii) in the case of Base Rate
Advances, telephonic notice not later than 12:00 noon (New York City time) on
the date of prepayment, to the Administrative Agent which specifies the
proposed date and aggregate principal amount of the prepayment and the Type of
Advances to be prepaid, and if such notice is given such Borrower shall, prepay
the outstanding principal amounts of the Revolving Credit Advances comprising
the same Borrowing in whole or ratably in part, together with accrued interest
to the date of such prepayment on the amount prepaid; provided, however, that
(A) each partial prepayment shall be in an aggregate principal amount not less
than $10,000,000 or an integral multiple of $1,000,000 in excess thereof and
(B) in the event of any such prepayment of Eurodollar Rate Advances on any day
other than the last day of an Interest Period for such Eurodollar Rate
Advances, such Borrower shall be obligated to reimburse the Lenders in respect
thereof pursuant to, and to the extent required by, Section 9.4(b); provided,
further, however, that such Borrower will use its best efforts to give notice
to the Administrative Agent of the proposed prepayment of Base Rate Advances on
the Business Day prior to the date of such proposed prepayment.

              (b)  Mandatory Prepayments.  If, at any time and from time to
time, the aggregate principal amount of Advances (other than Advances of
Objecting Lenders) then outstanding exceeds the Commitments of all the Lenders
after giving effect to any reduction of the Commitments pursuant to Section
2.9, the Borrowers shall immediately prepay the Revolving Credit Advances of
Lenders (other than Objecting Lenders) (to the extent there are such
outstanding Revolving Credit Advances) by an amount equal to such excess.

              SECTION 2.16  Increased Costs.  (a)  If, due to either (i) the
introduction after the date of this Agreement of or any change after the date
of this Agreement (including any change by
<PAGE>   36
                                                                              31



way of imposition or increase of reserve requirements or assessments other than
those referred to in the definition of "Eurodollar Reserve Percentage," "C/D
Reserve Percentage" or "C/D Assessment Rate" contained in Section 1.1) in or in
the interpretation of any law or regulation or (ii) the compliance with any
guideline or request issued or made after the date of this Agreement from or by
any central bank or other governmental authority (whether or not having the
force of law), in each case above other than those referred to in Section 2.17,
there shall be any increase in the cost to any Lender of agreeing to make, fund
or maintain, or of making, funding or maintaining, Eurodollar Rate Advances
funded in the interbank Eurodollar market, then the Borrowers shall from time
to time, upon demand by such Lender (with a copy of such demand to the
Administrative Agent), pay to the Administrative Agent for the account of such
Lender additional amounts sufficient to reimburse such Lender for all such
increased costs (except those costs incurred more than 60 days prior to the
date of such demand; for the purposes hereof any cost or expense allocable to a
period prior to the publication or effective date of such an introduction,
change, guideline or request shall be deemed to be incurred on the later of
such publication or effective date).  Each Lender agrees to use its best
efforts promptly to notify the Company of any event referred to in clause (i)
or (ii) above, provided that the failure to give such notice shall not affect
the rights of any Lender under this Section 2.16(a) (except as otherwise
expressly provided above in this Section 2.16(a)).  A certificate as to the
amount of such increased cost, submitted to the Company and the Administrative
Agent by such Lender, shall be conclusive and binding for all purposes, absent
manifest error.  After one or more Lenders have notified the Company of any
increased costs pursuant to this Section 2.16, the Company may specify by
notice to the Administrative Agent and the affected Lenders that, after the
date of such notice whenever the election of Eurodollar Rate Advances by the
applicable Borrower for an Interest Period or portion thereof would give rise
to such increased costs, such election shall not apply to the Revolving Credit
Advances of such Lenders during such Interest Period or portion thereof, and,
in lieu thereof, such Revolving Credit Advances shall during such Interest
Period or portion thereof be Base Rate Advances.  Each Lender agrees to use its
best efforts (including, without limitation, a reasonable effort to change its
lending office or to transfer its affected Advances to an affiliate of such
Lender) to avoid, or minimize the amount of, any demand for payment from the
Borrowers under this Section 2.16.

              (b)    In the event that any Lender shall change its lending
office and such change results (at the time of such change) in increased costs
to such Lender, the Borrowers shall not be liable to such Lender for such
increased costs incurred by such Lender to the extent, but only to the extent,
that such increased costs shall exceed the increased costs which such Lender
would have incurred if the lending office of such Lender had not been so
changed, but, subject to subsection (a) above and
<PAGE>   37
                                                                              32



to Section 2.18, nothing herein shall require any Lender to change its lending
office for any reason.

              SECTION 2.17  Increased Capital.  If either (a) the introduction
of or any change in or in the interpretation of any law or regulation or (b)
compliance by any Lender with any guideline or request from any central bank or
other governmental authority (whether or not having the force of law) affects
or would affect the amount of capital required or expected to be maintained by
such Lender or any corporation controlling such Lender and such Lender
determines that the amount of such capital is increased by or based upon the
existence of such Lender's commitment to lend hereunder and other commitments
of this type, then, within ten days after demand, and delivery to the Company
of the certificate referred to in the last sentence of this Section 2.17 by
such Lender (with a copy of such demand to the Administrative Agent), the
applicable Borrowers shall pay to the Administrative Agent for the account of
such Lender, from time to time as specified by such Lender, additional amounts
sufficient to compensate such Lender or such corporation in the light of such
circumstances, to the extent that such Lender reasonably determines such
increase in capital to be allocable to the existence of such Lender's
commitment to lend hereunder (except any such increase in capital incurred more
than, or compensation attributable to the period before, 90 days prior to the
date of such demand; for the purposes hereof any increase in capital allocable
to, or compensation attributable to, a period prior to the publication or
effective date of such an introduction, change, guideline or request shall be
deemed to be incurred on the later of such publication or effective date).
Each Lender agrees to use its best efforts promptly to notify the Company of
any event referred to in clause (a) or (b) above, provided that the failure to
give such notice shall not affect the rights of any Lender under this Section
2.17 (except as otherwise expressly provided above in this Section 2.17).  A
certificate in reasonable detail as to the basis for, and the amount of, such
compensation submitted to the Company by such Lender shall, in the absence of
manifest error, be conclusive and binding for all purposes.

              SECTION 2.18  Illegality.  Notwithstanding any other provision of
this Agreement, if the introduction of or any change in or in the
interpretation of any law or regulation shall make it unlawful, or any central
bank or other governmental authority shall assert that it is unlawful, for any
Lender or its lending office to perform its obligations hereunder to make
Eurodollar Rate Advances or to continue to fund or maintain such Advances
hereunder, such Lender may, by notice to the Company and the Administrative
Agent, suspend the right of the Borrowers to elect Eurodollar Rate Advances
from such Lender and, if necessary in the reasonable opinion of such Lender to
comply with such law or regulation, Convert all such Eurodollar Rate Advances
of such Lender to Base Rate Advances at the latest time permitted by the
applicable law or regulation, and such suspension and, if
<PAGE>   38
                                                                              33



applicable, such Conversion shall continue until such Lender notifies the
Company and the Administrative Agent that the circumstances making it unlawful
for such Lender to perform such obligations no longer exist (which such Lender
shall promptly do when such circumstances no longer exist).  So long as the
obligation of any Lender to make Eurodollar Rate Advances has been suspended
under this Section 2.18, all Notices of Borrowing specifying Advances of such
Type shall be deemed, as to such Lender, to be requests for Base Rate Advances.
Each Lender agrees to use its best efforts (including, without limitation, a
reasonable effort to change its lending office or to transfer its affected
Advances to an affiliate) to avoid any such illegality.

              SECTION 2.19 Payments and Computations.  (a)  The Borrowers shall
make each payment hereunder (including, without limitation, under Section 2.6,
2.8, 2.10 or 2.11) and under the Notes, whether the amount so paid is owing to
any or all of the Lenders or to the Administrative Agent, not later than 12:00
noon (New York City time) without setoff, counterclaim, or any other deduction
whatsoever, on the day when due in Dollars to the Administrative Agent at its
address at 270 Park Avenue, New York, New York 10017, Reference: El Paso
Natural Gas Company, or at such other location designated by notice to the
Company from the Administrative Agent and agreed to by the Company, in same day
funds.  The Administrative Agent will promptly thereafter cause to be
distributed like funds relating to the payment of principal or interest or
facility fees ratably (other than amounts payable pursuant to Section 2.12,
2.16, 2.17, 2.18 or 2.20) according to the respective amounts of such
principal, interest or facility fees then due and owing to the Lenders, and
like funds relating to the payment of any other amount payable to any Lender to
such Lender, in each case to be applied in accordance with the terms of this
Agreement.  Upon its acceptance of an Assignment and Acceptance and recording
of the information contained therein in the Register pursuant to Section
9.7(d), from and after the effective date specified in such Assignment and
Acceptance, the Administrative Agent shall make all payments hereunder and
under the Notes in respect of the interest assigned thereby to the Lender
assignee thereunder, and the parties to such Assignment and Acceptance shall
make all appropriate adjustments in such payments for periods prior to such
effective date directly between themselves.

              (b)    All computations of interest based on the Prime Rate and
of facility fees shall be made by the Administrative Agent on the basis of a
year of 365 or 366 days, as the case may be, and all computations of interest
based on the Eurodollar Rate, the Base CD Rate or the Effective Federal Funds
Rate shall be made by the Administrative Agent, and all computations of
interest pursuant to Section 2.12 shall be made by each Lender with respect to
its own Advances, on the basis of a year of 360 days, in each case for the
actual number of days (including the first day but excluding the last day)
occurring in the period for which such interest or fees are payable.  Each
determination by
<PAGE>   39
                                                                              34



the Administrative Agent (or, in the case of Section 2.12, 2.16, 2.17, 2.18 or
2.20, by each Lender with respect to its own Advances) of an interest rate or
an increased cost or increased capital or of illegality hereunder shall be
conclusive and binding for all purposes if made reasonably and in good faith.

              (c)    Whenever any payment hereunder or under the Notes shall be
stated to be due on a day other than a Business Day, such payment shall be made
on the next succeeding Business Day, and such extension of time shall in such
case be included in the computation of payment of interest; provided, however,
if such extension would cause payment of interest on or principal of Eurodollar
Rate Advances to be made in the next following calendar month, such payment
shall be made on the next preceding Business Day.

              (d)    Unless the Administrative Agent shall have received notice
from the Company or any other applicable Borrower prior to the date on which
any payment is due to the Lenders hereunder that the applicable Borrower will
not make such payment in full, the Administrative Agent may assume that the
applicable Borrower has made such payment in full to the Administrative Agent
on such date and the Administrative Agent may, in reliance upon such
assumption, cause to be distributed to each Lender on such due date an amount
equal to the amount then due such Lender.  If and to the extent the applicable
Borrower shall not have so made such payment in full to the Administrative
Agent, each Lender shall repay to the Administrative Agent forthwith on demand
such amount distributed to such Lender together with interest thereon, for each
day from the date such amount is distributed to such Lender until the date such
Lender repays such amount to the Administrative Agent, at a rate equal to the
Effective Federal Funds Rate for such day.

              SECTION 2.20  Taxes.  (a)  Any and all payments by the Borrowers
hereunder or under the Notes to each Indemnified Party shall be made, in
accordance with Section 2.19, free and clear of and without deduction for any
and all present or future taxes, levies, imposts, deductions, charges or
withholdings, and all liabilities with respect thereto, excluding all taxes,
levies, imposts, deductions, charges or withholdings, and all liabilities with
respect thereto, imposed by the jurisdiction under the laws of which such
Indemnified Party is organized, domiciled, resident or doing business, or any
political subdivision thereof or by any jurisdiction in which such Indemnified
Party holds any interest in connection with this Agreement or any Note
(including, without limitation, in the case of each Lender, the jurisdiction of
such Lender's lending office) or any political subdivision thereof, other than
by any jurisdiction with which the Indemnified Party's connection arises solely
from having executed, delivered or performed obligations or received a payment
under, or enforced, this Agreement or any Note (all such non-excluded taxes,
levies, imposts, deductions, charges, withholdings and liabilities being
hereinafter referred
<PAGE>   40
                                                                              35



to as "Taxes").  If any Borrower shall be required by law to deduct any Taxes
from or in respect of any sum payable hereunder or under any Note to any
Indemnified Party, (i) the sum payable shall be increased as may be necessary
so that after making all required deductions (including deductions applicable
to additional sums payable under this Section 2.20) such Indemnified Party
receives an amount equal to the sum it would have received had no such
deductions been made, (ii) such Borrower shall make or cause to be made such
deductions and (iii) such Borrower shall pay or cause to be paid the full
amount deducted to the relevant taxation authority or other authority in
accordance with applicable law, provided that the Borrowers shall not be
required to pay any additional amount (and shall be relieved of any liability
with respect thereto) pursuant to this subsection (a) to any Indemnified Party
that either (A) on the date such Lender became an Indemnified Party hereunder,
(I) was not entitled to submit a U.S. Internal Revenue Service form 1001
(relating to such Indemnified Party, and entitling it to a complete exemption
from United States withholding taxes on all amounts to be received by such
Indemnified Party pursuant to this Agreement) and a U.S. Internal Revenue
Service form 4224 (relating to all amounts to be received by such Indemnified
Party pursuant to this Agreement) and (II) was not a United States person (as
such term is defined in Section 7701(a)(30) of the Internal Revenue Code) or
(B) has failed to submit any form or certificate that it was required to file
or provide pursuant to subsection (d) of this Section 2.20 and is entitled to
file or give, as applicable, under applicable law, provided, further, that
should an Indemnified Party become subject to Taxes because of its failure to
deliver a form required hereunder, the Borrowers shall take such steps as such
Indemnified Party shall reasonably request to assist such Indemnified Party to
recover such Taxes, and provided, further, that each Indemnified Party, with
respect to itself, agrees to indemnify and hold harmless the Borrowers from any
taxes, penalties, interest and other expenses, costs and losses incurred or
payable by the Borrowers as a result of the failure of any of the Borrowers to
comply with its obligations under clause (ii) or (iii) above in reliance on any
form or certificate provided to it by such Indemnified Party pursuant to this
Section 2.20.  If any Indemnified Party receives a net credit or refund in
respect of such Taxes or amounts so paid by the Borrowers, it shall promptly
notify the Company of such net credit or refund and shall promptly pay such net
credit or refund to the applicable Borrower, provided that the applicable
Borrower agrees to return such net credit or refund if the Indemnified Party to
which such net credit or refund is applicable is required to repay it.

              (b)    In addition, each Borrower agrees to pay any present or
future stamp or documentary taxes or any other excise or property taxes,
charges or similar levies which arise from any payment made by such Borrower
hereunder or under the Notes or from the execution, delivery or performance of,
or otherwise with
<PAGE>   41
                                                                              36



respect to, this Agreement or the Notes (hereinafter referred to as "Other
Taxes").

              (c)    Each Borrower will indemnify each Indemnified Party and
the Administrative Agent for the full amount of Taxes or Other Taxes
(including, without limitation, any Taxes or Other Taxes imposed by any
jurisdiction on amounts payable under this Section 2.20) paid by such
Indemnified Party and any liability (including penalties, interest and
expenses) arising therefrom or with respect thereto except as a result of the
gross negligence (which shall in any event include the failure of such
Indemnified Party to provide to the Borrowers any form or certificate that it
was required to provide pursuant to subsection (d) below) or willful misconduct
of such Indemnified Party, whether or not such Taxes or Other Taxes were
correctly or legally asserted.  This indemnification shall be made within 30
days from the date such Indemnified Party makes written demand therefor.

              (d)    On or prior to the date on which each Indemnified Party
organized under the laws of a jurisdiction outside the United States becomes an
Indemnified Party hereunder, such Indemnified Party shall provide the Company
with U.S. Internal Revenue Service form 1001 or 4224, as appropriate, or any
successor form prescribed by the U.S. Internal Revenue Service, certifying that
such Indemnified Party is fully exempt from United States withholding taxes
with respect to all payments to be made to such Indemnified Party hereunder, or
other documents satisfactory to the Company indicating that all payments to be
made to such Indemnified Party hereunder are fully exempt from such taxes.
Thereafter and from time to time (but only so long as such Indemnified Party
remains lawfully able to do so), each such Indemnified Party shall submit to
the Company such additional duly completed and signed copies of one or the
other of such Forms (or such successor Forms as shall be adopted from time to
time by the relevant United States taxing authorities) as may be (i) notified
by any Borrower to such Indemnified Party and (ii) required under then-current
United States law or regulations to avoid United States withholding taxes on
payments in respect of all amounts to be received by such Indemnified Party
pursuant to this Agreement or the Notes.  Upon the request of any Borrower from
time to time, each Indemnified Party that is a United States person (as such
term is defined in Section 7701(a)(30) of the Internal Revenue Code) shall
submit to the Company a certificate to the effect that it is such a United
States person.  If any Indemnified Party determines, as a result of any change
in applicable law, regulation or treaty, or in any official application or
interpretation thereof, that it is unable to submit to the Company any form or
certificate that such Indemnified Party is obligated to submit pursuant to this
subsection (d), or that such Indemnified Party is required to withdraw or
cancel any such form or certificate previously submitted, such Indemnified
Party shall promptly notify the Company of such fact.
<PAGE>   42
                                                                              37



              (e)    Any Indemnified Party claiming any additional amounts
payable pursuant to this Section 2.20 shall use its best efforts (consistent
with its internal policy and legal and regulatory restrictions) to change the
jurisdiction of its lending office if the making of such a change would avoid
the need for, or reduce the amount of, any such additional amounts which may
thereafter accrue and would not, in the reasonable judgment of such Indemnified
Party, be otherwise disadvantageous to such Indemnified Party.

              (f)    Without prejudice to the survival of any other agreement
of the Borrowers hereunder, the agreements and obligations of the Borrowers and
each Indemnified Party contained in this Section 2.20 shall survive the payment
in full of principal and interest hereunder and under the Notes.

              (g)    Any other provision of this Agreement to the contrary
notwithstanding, any amounts which are payable by any Borrower under this
Section 2.20 shall not be payable under Section 2.16.

              SECTION 2.21  Sharing of Payments, Etc.  If any Lender shall
obtain any payment (whether voluntary, involuntary, through the exercise of any
right of set-off, or otherwise) on account of the Advances made by it (other
than pursuant to Section 2.12, 2.16, 2.17, 2.18 or 2.20) in excess of its
ratable share of payments on account of the Advances obtained by all the
Lenders, such Lender shall forthwith purchase from the other Lenders such
participations in the Advances made by them as shall be necessary to cause such
purchasing Lender to share the excess payment ratably with each of them,
provided, however, that if all or any portion of such excess payment is
thereafter recovered from such purchasing Lender, such purchase from each
Lender shall be rescinded and each Lender shall repay to the purchasing Lender
the purchase price to the extent of such recovery together with an amount equal
to such Lender's ratable share (according to the proportion of (a) the amount
of such Lender's required repayment to (b) the total amount so recovered from
the purchasing Lender) of any interest or other amount paid or payable by the
purchasing Lender in respect of the total amount so recovered.  Each Borrower
agrees that any Lender so purchasing a participation from another Lender
pursuant to this Section may, to the fullest extent permitted by law, exercise
all its rights of payment (including the right of set-off) with respect to such
participation as fully as if such Lender were the direct creditor of such
Borrower in the amount of such participation.

              SECTION 2.22  Use of Proceeds.  Proceeds of the Advances may be
used for general corporate purposes of the Borrowers and their respective
Subsidiaries, including, without limitation, for acquisitions and for payment
of commercial paper issued by the Borrowers and to refinance the loans under
the Existing Facilities.
<PAGE>   43
                                                                              38




              SECTION 2.23  Replacement of Lenders.  If any Lender requests
compensation under Sections 2.12, 2.16 or 2.17 or if any Borrower is required
to pay any additional amount to any Lender or any Governmental Authority for
the account of any Lender pursuant to Section 2.20, or if any Lender defaults
in its obligation to fund Advances hereunder, then the Company may, at its sole
expense and effort, upon notice to such Lender and the Administrative Agent,
require such Lender to assign and delegate, without recourse (in accordance
with and subject to the restrictions contained in Section 9.7), all its
interests, rights and obligations under this Agreement (other than any
outstanding CAF Advances held by it) to an assignee that shall assume such
obligations (which assignee may be another Lender, if a Lender accepts such
assignment); provided that (i) the Company shall have received the prior
written consent of the Administrative Agent, which consent shall not
unreasonably be withheld, (ii) such Lender shall have received payment of an
amount equal to the outstanding principal of its Advances (other than CAF
Advances), accrued interest thereon, accrued fees and all other amounts payable
to it hereunder, from the assignee (to the extent of such outstanding principal
and accrued interest and fees) or the Borrowers (in the case of all other
amounts) and (iii) in the case of any such assignment resulting from a claim
for compensation under Sections 2.12 , 2.16 or 2.17 or payments required to be
made pursuant to Section 2.20, such assignment will result in a reduction in
such compensation or payments.  A Lender shall not be required to make any such
assignment and delegation if, prior thereto, as a result of a waiver by such
Lender or otherwise, the circumstances entitling the Company to require such
assignment and delegation cease to apply.


                                  ARTICLE III

                    CONDITIONS OF EFFECTIVENESS AND LENDING

              SECTION 3.1  Conditions Precedent to Effectiveness of this
Agreement.  This Agreement shall become effective (the "Effective Date") when
(i) it shall have been executed by EPNGC, the Administrative Agent and the CAF
Advance Agent, (ii) the Administrative Agent and EPNGC either shall have been
notified by each Lender that such Lender has executed it or shall have received
a counterpart of this Agreement executed by such Lender, and (iii) the
Administrative Agent shall have received notice from the "Administrative Agent"
under the Tennessee Facility that the "Effective Date" has occurred, or
substantially simultaneously therewith is occurring, under the Tennessee
Facility, and if any Lender is not also a party to the Tennessee Facility, such
Lender shall have received all documents delivered pursuant to Section 3.1 of
the Tennessee Facility, in each case above, unless waived by the Lenders in
accordance with this Agreement.  Anything in this Agreement to the contrary
notwithstanding, if all of the conditions to effectiveness of this Agreement
specified in this Section 3.1 shall not have been
<PAGE>   44
                                                                              39



fulfilled on or before December 31, 1996, (i) the Company shall on such date
pay all accrued and unpaid facility fees pursuant to Section 2.8 and (ii) this
Agreement, and all of the obligations of EPNGC, the Lenders, the Administrative
Agent and the CAF Advance Agent hereunder, shall be terminated on and as of
5:00 P.M. (New York City time) on December 31, 1996; provided, however, that as
soon as the Administrative Agent determines that all of the conditions to
effectiveness of this Agreement specified in this Section 3.1 shall have been
fulfilled on or before December 31, 1996, the Administrative Agent shall
furnish written notice to EPNGC, the Lenders and the "Administrative Agent"
under the Tennessee Facility to the effect that it has so determined, and such
notice by the Administrative Agent shall constitute conclusive evidence that
this Agreement shall have become effective for all purposes.  Notwithstanding
the foregoing, the obligations of the Company to pay fees pursuant to Section
2.8 as well as all obligations of the Borrowers pursuant to Section 9.4 shall
survive the termination of this Agreement.

              SECTION 3.2  Conditions Precedent to Initial Advances.  The
agreement of each Lender to make the initial Advances to be made by it to the
Borrowers hereunder is subject to (the date upon which all conditions listed in
Section 3.2(a) and 3.2(b) are satisfied, the "Closing Date") (a) the occurrence
of the Effective Date hereunder and the "Closing Date" under the Tennessee
Facility) and (b) the receipt by the Administrative Agent of the following in
form and substance satisfactory to the Administrative Agent and in sufficient
copies for each Lender:

              (i)    Certified copies of the resolutions of the Board of
       Directors of EPNGC approving the borrowings contemplated hereby and
       authorizing the execution of this Agreement and the Notes, and of all
       documents evidencing other necessary corporate action of EPNGC and
       governmental approvals to EPNGC, if any, with respect to this Agreement
       and the Notes.

              (ii)   A certificate of the Secretary or an Assistant Secretary
       of EPNGC certifying the names and true signatures of the officers of
       EPNGC authorized to sign this Agreement and the other documents to be
       delivered by it hereunder.

              (iii)  A favorable opinion of the General Counsel of EPNGC, or
       the Associate General Counsel of EPNGC, in substantially the form of
       Exhibit G hereto.

              (iv)    A favorable opinion of Jones, Day, Reavis & Pogue, New
       York counsel to EPNGC, in substantially the form of Exhibit H hereto.

              (v)    A letter from the Process Agent, in substantially the form
       of Exhibit I hereto, agreeing to act as Process Agent for EPNGC and to
       forward forthwith all process received by it to EPNGC.
<PAGE>   45
                                                                              40



              (vi)   Evidence satisfactory to the Administrative Agent that all
       advances, accrued interest and other fees and any other amounts (except
       as provided under Section 9.12) owing to the lenders and the agents
       under the $400,000,000 Revolving Credit and Competitive Advance Facility
       Agreement and the $100,000,000 Revolving Credit and Competitive Advance
       Facility Agreement, each dated as of May 31, 1996 (the "Existing
       Facilities"), among EPNGC, the several financial institutions from time
       to time parties thereto, and Chase, as Administrative Agent and CAF
       Advance Agent, shall have been paid in full, and the commitments to make
       advances thereunder shall have been cancelled.

              SECTION 3.3  Conditions Precedent to Initial Advances to Any
Borrowing Subsidiary or Holding.  The agreement of each Lender to make the
initial Advances to be made by it to any Borrowing Subsidiary or Holding is
further subject to the Administrative Agent receiving the following, in form
and substance satisfactory to the Administrative Agent and (except for the
Notes) in sufficient copies for each Lender (provided that no Subsidiary of
Holding which is not a Subsidiary of EPNGC may become a Borrower hereunder
unless Holding is a Borrower hereunder):

              (a)    A Joinder Agreement executed and delivered by such
       Borrowing Subsidiary or Holding, as the case may be, conforming to the
       requirements hereof.

              (b)    Notes, dated the date such Borrowing Subsidiary or
       Holding, as the case may be, executes and delivers its Joinder
       Agreement, made by such Borrowing Subsidiary or Holding, as the case may
       be, to the order of each Lender requesting a Note, respectively.

              (c)    A certificate of the Secretary or an Assistant Secretary
       of such Borrowing Subsidiary or Holding, as the case may be, certifying
       the names and true signature of the officers of such Borrowing
       Subsidiary or Holding, as the case may be, authorized to sign the
       Joinder Agreement and the other documents to be delivered by it
       hereunder.

              (d)    A favorable opinion of the General Counsel or Associate
       General Counsel of the Company, given upon the express instructions of
       the Company, in substantially the form of Exhibit K hereto, and as to
       such other matters as any Lender through the Administrative Agent may
       reasonably request, with such assumptions, qualifications and exceptions
       as the Administrative Agent may approve.

              (e)    A favorable opinion of Jones, Day, Reavis & Pogue or other
       New York counsel to the Company reasonably satisfactory to the
       Administrative Agent, in substantially the form of Exhibit L hereto, and
       as to such other matters as any Lender through the Administrative Agent
       may
<PAGE>   46
                                                                              41



       reasonably request, with such assumptions, qualifications and exceptions
       as the Administrative Agent may approve.

              (f)    A letter from the Process Agent, in substantially  the
       form of Exhibit I hereto, agreeing to act as Process Agent for such
       Borrowing Subsidiary or Holding, as the case may be, and to forward
       forthwith all process received by it to such Borrowing Subsidiary or
       Holding, as the case may be.

              SECTION 3.4  Conditions Precedent to Each Borrowing. The
obligation of each Lender to make an Advance (including the initial Advance,
but excluding any continuation or Conversion of an Advance) on the occasion of
any Borrowing shall be subject to the conditions precedent that on the date of
such Borrowing this Agreement shall have become effective pursuant to Section
3.1 and, before and immediately after giving effect to such Borrowing and to
the application of the proceeds therefrom, the following statements shall be
true and correct, and the giving by the applicable Borrower or the Company on
such Borrower's behalf of the applicable Notice of Borrowing and the acceptance
by the applicable Borrower of the proceeds of such Borrowing shall constitute
its representation and warranty that on and as of the date of such Borrowing,
before and immediately after giving effect thereto and to the application of
the proceeds therefrom, the following statements are true and correct:

              (i)    each representation and warranty contained in Section 4.1
       is correct in all material respects as though made on and as of such
       date; and

              (ii)   no event has occurred and is continuing, or would result
       from such Borrowing, which constitutes an Event of Default or would
       constitute an Event of Default but for the requirement that notice be
       given or time elapse or both.


                                   ARTICLE IV

                         REPRESENTATIONS AND WARRANTIES

              SECTION 4.1  Representations and Warranties of the Borrowers.
Each Borrower represents and warrants as follows:

              (a)    The Company is a corporation duly incorporated, validly
       existing and in good standing under the laws of the State of Delaware.
       Each Principal Subsidiary and each Restricted Affiliate is duly
       incorporated, validly existing and in good standing in the jurisdiction
       of its incorporation.  The Company, each Principal Subsidiary and each
       Restricted Affiliate possess all corporate powers and all other
       authorizations and licenses necessary to engage in its business and
       operations as now conducted, the failure to obtain or maintain which
       would have a Material Adverse Effect.
<PAGE>   47
                                                                              42




              (b)    The execution, delivery and performance by (i) each
       Borrower of this Agreement, each Joinder Agreement, if any, to which it
       is a party and its Notes (as applicable) and (ii) each Restricted
       Affiliate of its Restricted Affiliate Guaranty are within such
       Borrower's or Restricted Affiliate's, as the case may be, corporate
       powers, have been duly authorized by all necessary corporate action, and
       do not contravene (A) such Borrower's or Restricted Affiliate's, as the
       case may be, charter or by-laws or (B) any law or any material
       contractual restriction binding on or affecting such Borrower or
       Restricted Affiliate, as the case may be.

              (c)    No authorization or approval or other action by, and no
       notice to or filing with, any governmental authority or regulatory body
       is required for the due execution, delivery and performance by (i) such
       Borrower of this Agreement, each Joinder Agreement, if any, to which it
       is a party or its Notes (as applicable) or (ii) any Restricted Affiliate
       of its Restricted Affiliate Guaranty, except filings necessary to comply
       with laws, rules, regulations and orders required in the ordinary course
       to comply with ongoing obligations of such Borrower under Section 5.1(a)
       and (b).

              (d)    This Agreement constitutes, its Notes and each Joinder
       Agreement, if any, to which it is a party (as applicable) when delivered
       hereunder shall constitute and its Restricted Affiliate Guaranty when
       delivered hereunder shall constitute, the legal, valid and binding
       obligations of each Borrower or Restricted Affiliate, as the case may
       be, enforceable against such Borrower or Restricted Affiliate, as the
       case may be, in accordance with their respective terms, except as may be
       limited by any applicable bankruptcy, insolvency, reorganization,
       moratorium or similar laws affecting creditors' rights generally or by
       general principles of equity.

              (e)    The consolidated balance sheet of EPNGC and its
       consolidated Subsidiaries as at December 31, 1995, and the related
       consolidated statements of income and cash flows of EPNGC and its
       consolidated Subsidiaries for the fiscal year then ended, reported on by
       Coopers & Lybrand LLP, independent public accountants, copies of which
       have been furnished to the Administrative Agent and the Lenders prior to
       the date hereof, fairly present the consolidated financial condition of
       EPNGC and its consolidated Subsidiaries as at such date and the
       consolidated results of the operations of EPNGC and its consolidated
       Subsidiaries for the period ended on such date, all in accordance with
       generally accepted accounting principles consistently applied, and since
       December 31, 1995, there has been no material adverse change in such
       condition or operations.  The unaudited consolidated balance sheet of
       EPNGC and its
<PAGE>   48
                                                                              43



       consolidated Subsidiaries as of June 30, 1996, and the related
       consolidated statements of income and cash flows of EPNGC and its
       consolidated Subsidiaries for the six months then ended, certified by
       the chief financial officer of EPNGC, copies of which have been
       furnished to the Administrative Agent and the Lenders prior to the date
       hereof, fairly present the consolidated results of operations of EPNGC
       and its consolidated Subsidiaries for the three months then ended, all
       in accordance with generally accepted accounting principles consistently
       applied (except as approved by the chief financial officer of EPNGC and
       as disclosed therein) and subject to normal year-end audit adjustments.


              (f)    The unaudited pro forma combined balance sheet of EPNGC
       and Tenneco Energy as at June 30, 1996 and the related unaudited pro
       forma combined statements of income of EPNGC and Tenneco Energy for the
       six-month period ended June 30, 1996 set forth in the Joint Proxy
       Statement, copies of which have been delivered to the Lenders, were
       prepared from financial statements referred to in Section 4.1(e), which
       were prepared in accordance with generally accepted accounting
       principles, are complete and correct in all material respects and have
       been prepared on the basis described therein and show the combined
       financial position and results of operations of EPNGC and Tennessee as
       if the Transaction had occurred, in the case of the combined balance
       sheet, on June 30, 1996, and in the case of combined statements of
       income, as of January 1, 1995.

              (g)    Each of the Company and its Subsidiaries is in compliance
       with all laws, rules, regulations and orders of any governmental
       authority applicable to it or its property except where the failure to
       comply, individually or in the aggregate, would not in the reasonable
       judgment of the Company be expected to result in a Material Adverse
       Effect.

              (h)    There is no action, suit or proceeding pending, or to the
       knowledge of any Borrower threatened, against or involving the Company,
       any Principal Subsidiary or any Restricted Affiliate in any court, or
       before any arbitrator of any kind, or before or by any governmental
       body, which in the reasonable judgment of the Company (taking into
       account the exhaustion of all appeals) would have a Material Adverse
       Effect, or which purports to affect the legality, validity, binding
       effect or enforceability of this Agreement or the Notes.

              (i)    The Company, each Principal Subsidiary and each Restricted
       Affiliate have duly filed all tax returns required to be filed, and have
       duly paid and discharged all taxes, assessments and governmental charges
       upon it or against its properties now due and payable, the failure to
       pay which would have a Material Adverse Effect, unless and
<PAGE>   49
                                                                              44



       to the extent only that the same are being contested in good faith and
       by appropriate proceedings by the Company, the appropriate Subsidiary or
       the appropriate Restricted Affiliate.

              (j)    The Company, each Principal Subsidiary and each Restricted
       Affiliate have good title to their respective properties and assets,
       free and clear of all mortgages, liens and encumbrances, except for
       mortgages, liens and encumbrances (including covenants, restrictions,
       rights, easements and minor irregularities in title) which do not
       materially interfere with the business or operations of the Company,
       such Subsidiary or such Restricted Affiliate as presently conducted or
       which are permitted by Section 5.2(a), and except that no representation
       or warranty is being made with respect to Margin Stock.

              (k)    No Termination Event has occurred or is reasonably
       expected to occur with respect to any Plan which, with the giving of
       notice or lapse of time, or both, would constitute an Event of Default
       under Section 7.1(g).

              (l)    Each Plan has complied with the applicable provisions of
       ERISA and the Code where the failure to so comply would reasonably be
       expected to result in an aggregate liability that would exceed 10% of
       the Net Worth of the Company.

              (m)    The statement of assets and liabilities of each Plan other
       than, prior to the Merger, any Plan of Tennessee or any of its
       Subsidiaries and the statements of changes in fund balance and in
       financial position, or the statement of changes in net assets available
       for plan benefits, for the most recent plan year for which an
       accountant's report with respect to such Plan has been prepared, copies
       of which report have been furnished to the Administrative Agent, fairly
       present the financial condition of such Plan as at such date and the
       results of operations of such Plan for the plan year ended on such date.

              (n)    Neither the Company nor any ERISA Affiliate has incurred,
       or is reasonably expected to incur, any Withdrawal Liability to any
       Multiemployer Plan which, when aggregated with all other amounts
       required to be paid to Multiemployer Plans in connection with Withdrawal
       Liability (as of the date of determination), would exceed 10% of the Net
       Worth of the Company.

              (o)    Neither the Company nor any ERISA Affiliate has received
       any notification that any Multiemployer Plan is in reorganization,
       insolvent or has been terminated, within the meaning of Title IV of
       ERISA, and no Multiemployer Plan is reasonably expected to be in
       reorganization, insolvent or to be terminated within the meaning of
       Title IV of ERISA the
<PAGE>   50
                                                                              45



       effect of which reorganization, insolvency or termination would be the
       occurrence of an Event of Default under Section 7.1(i).

              (p)    The Borrowers are not engaged in the business of extending
       credit for the purpose of purchasing or carrying Margin Stock, and no
       proceeds of any Advance will be used to extend credit to others (other
       than to any Subsidiary of the Company) for the purpose of purchasing or
       carrying Margin Stock.

              (q)    No Borrower is an "investment company" or a "company"
       controlled by an "investment company" within the meaning of the
       Investment Company Act of 1940, as amended.

              (r)    No Borrower is a "holding company" or a "subsidiary
       company" of a "holding company" within the meaning of the Public Utility
       Holding Company Act of 1935, as amended.

              (s)    The borrowings by the Borrowers under this Agreement and
       the Notes and the applications of the proceeds thereof as provided
       herein will not violate Regulation G, T, U or X of the Board of
       Governors of the Federal Reserve System.

All representations and warranties made by the Borrowers herein or made in any
certificate delivered pursuant hereto shall survive the making of the Advances
and the execution and delivery to the Lenders of this Agreement and the Notes.


                                   ARTICLE V

                           COVENANTS OF THE BORROWERS

              SECTION 5.1  Affirmative Covenants.  So long as any amount
payable by any Borrower hereunder or under any Note shall remain unpaid or any
Lender shall have any Commitment hereunder, each Borrower will, unless the
Majority Lenders shall otherwise consent in writing:

              (a)    Preservation of Corporate Existence, Etc.  Preserve and
       maintain, and, in the case of the Company, cause each Principal
       Subsidiary and each Restricted Affiliate to preserve and maintain, its
       corporate existence, rights (charter and statutory) and material
       franchises, except as otherwise permitted by Section 5.2(d) or 5.2(e).

              (b)    Compliance with Laws, Etc.  Comply, and, in the case of
       the Company, cause each Principal Subsidiary and each Restricted
       Affiliate to comply, in all material respects with all applicable laws,
       rules, regulations and orders (including, without limitation, all
       environmental
<PAGE>   51
                                                                              46



       laws and laws requiring payment of all taxes, assessments and
       governmental charges imposed upon it or upon its property except to the
       extent contested in good faith by appropriate proceedings) the failure
       to comply with which would have a Material Adverse Effect.

              (c)    Visitation Rights.  At any reasonable time and from time
       to time, permit the Administrative Agent or any of the Lenders or any
       agents or representatives thereof, to examine and make copies of and
       abstracts from the records and books of account of, and visit the
       properties of, the Company, any of its Subsidiaries and any Restricted
       Affiliate, and to discuss the affairs, finances and accounts of the
       Company, any of its Subsidiaries and any Restricted Affiliate with any
       of their officers and with their independent certified public
       accountants.

              (d)    Books and Records.  Keep, and, in the case of the Company,
       cause each of its Subsidiaries and each Restricted Affiliate to keep,
       proper books of record and account, in which full and correct entries
       shall be made of all its respective financial transactions and the
       assets and business of the Company, each of its Subsidiaries and each
       Restricted Affiliate, as applicable, in accordance with generally
       accepted accounting principles either (i) consistently applied or (ii)
       applied in a changed manner provided such change shall have been
       disclosed to the Administrative Agent and shall have been consented to
       by the accountants which (as required by Section 5.3(b)) report on the
       financial statements of the Company and its consolidated Subsidiaries
       for the fiscal year in which such change shall have occurred.

              (e)    Maintenance of Properties, Etc.  Maintain and preserve,
       and, in the case of the Company, cause each Principal Subsidiary and
       each Restricted Affiliate to maintain and preserve, all of its
       properties which are used in the conduct of its business in good working
       order and condition, ordinary wear and tear excepted, to the extent that
       any failure to do so would have a Material Adverse Effect.

              (f)    Maintenance of Insurance.  Maintain, and, in the case of
       the Company, cause each Principal Subsidiary and each Restricted
       Affiliate to maintain, insurance with responsible and reputable
       insurance companies or associations in such amounts and covering such
       risks as is usually carried by companies engaged in similar businesses
       and owning similar properties in the same general areas in which the
       Company, such Subsidiary or such Restricted Affiliate operates.

              (g)    Holding.  Once Holding is formed, cause (i) Holding to
       execute and deliver a guaranty (in form and
<PAGE>   52
                                                                              47



       substance reasonably satisfactory to the Administrative Agent) (the
       "Holding Guarantee") in favor of the Administrative Agent, for the
       ratable benefit of the Lenders, guaranteeing the prompt and complete
       payment by each Borrower when due (whether at the stated maturity, by
       acceleration or otherwise) of the Obligations owing by such Borrower and
       (ii) the delivery to the Administrative Agent of legal opinions from the
       General Counsel or the Associate General Counsel of Holding and from New
       York counsel to Holding reasonably acceptable to the Administrative
       Agent, which legal opinions shall be in form and substance reasonably
       satisfactory to the Administrative Agent.

              SECTION 5.2  Negative Covenants.  So long as any amount payable
by any Borrower hereunder or under any Note shall remain unpaid or any Lender
shall have any Commitment hereunder, each Borrower will not, unless the
Majority Lenders shall otherwise consent in writing:

              (a)    Liens, Etc.  (i) Create, assume or suffer to exist, or, in
       the case of the Company, permit any Principal Subsidiary to create,
       assume or suffer to exist, any Liens upon or with respect to any of the
       capital stock of any Principal Subsidiary, whether now owned or
       hereafter acquired, or (ii) create or assume, or, in the case of the
       Company, permit any Principal Subsidiary or any Restricted Affiliate to
       create or assume, any Liens upon or with respect to any other assets
       material to the consolidated operations of the Company and its
       consolidated Subsidiaries taken as a whole securing the payment of
       Indebtedness and Guaranties in an aggregate amount (determined without
       duplication of amount (so that the amount of a Guarantee will be
       excluded to the extent the Indebtedness Guaranteed thereby is included
       in computing such aggregate amount)) exceeding $100,000,000; provided,
       however, that this subsection (a) shall not apply to:

                     (A)    Liens on the stock or assets of any Project
              Financing Subsidiary or any Restricted Affiliate (or any
              partnership, member or other equity interest in or assets of any
              partnership, limited liability company or other entity of which
              the Project Financing Subsidiary is a partner, member or other
              equity participant) securing the payment of a Project Financing
              and related obligations;

                     (B)    Liens on assets acquired by the Company, any of its
              Subsidiaries or any Restricted Affiliate after February 11, 1992
              to the extent that such Liens existed at the time of such
              acquisition and (except as otherwise permitted under clause (F)
              below) were not placed thereon by or with the consent of the
              Company in contemplation of such acquisition;
<PAGE>   53
                                                                              48



                     (C)    Liens created by any Alternate Program or any
              document executed by any Borrower or any Restricted Affiliate in
              connection therewith;

                     (D)    Liens on Margin Stock;

                     (E)    Liens for taxes, assessments or governmental
              charges or levies not yet overdue; and

                     (F)    Liens on assets of Tennessee and its Subsidiaries
              existing immediately prior to the Merger and not prohibited by
              the Tennessee Facility.

              (b)    Consolidated Debt and Guarantees to Capitalization.  (i)
       Permit the ratio of (A) the sum of (1) the aggregate amount of
       consolidated Debt of EPNGC and its consolidated Subsidiaries and all
       Restricted Affiliates and their consolidated Subsidiaries (without
       duplication of amount under this clause (A) and determined as to all of
       the foregoing entities on a consolidated basis) plus (2) the aggregate
       amount of consolidated Guaranties of EPNGC and its consolidated
       Subsidiaries and all Restricted Affiliates and their consolidated
       Subsidiaries (without duplication of amount under this clause (A) and
       determined as to all of the foregoing entities on a consolidated basis)
       to (B) Capitalization of EPNGC and all Restricted Affiliates (without
       duplication and determined as to all of the foregoing entities on a
       consolidated basis) to exceed .7 to 1; and (ii) from and after the date
       that Holding becomes a Borrower hereunder, permit the ratio of (A) the
       sum of (1) the aggregate amount of consolidated Debt of Holding and its
       consolidated Subsidiaries plus (2) the aggregate amount of consolidated
       Guaranties of Holding and its consolidated Subsidiaries to (B)
       Capitalization of Holding to exceed .7 to 1.

              (c)    Debt, Etc.  In the case of the Company, permit any of its
       consolidated Subsidiaries to create or suffer to exist any Debt, any
       Guaranty or any reimbursement obligation with respect to any letter of
       credit (other than any Project Financing), if, immediately after giving
       effect to such Debt, Guaranty or reimbursement obligation and the
       receipt and application of any proceeds thereof or value received in
       connection therewith, the aggregate amount (determined without
       duplication of amount) of Debt, Guaranties and letter of credit
       reimbursement obligations of the Company's consolidated Subsidiaries
       (other than any Project Financing) determined on a consolidated basis
       would exceed $150,000,000; provided, however, that the following Debt,
       Guaranties or reimbursement obligations shall be excluded from the
       application of, and calculation set forth in, this paragraph (c): (A)
       Debt, Guaranties or reimbursement obligations incurred by (x) Mojave or
       (y) so long as it is a Borrower, EPNGC, (B) Debt, Guaranties or
       reimbursement
<PAGE>   54
                                                                              49



       obligations arising under this Agreement or the Tennessee Facility or
       the $250,000,000 Revolving Credit and Competitive Advance Facility
       Agreement, dated as of the date hereof, among EPNGC, the lenders parties
       thereto and Chase, as Administrative Agent and CAF Advance Agent, (C)
       Debt, Guaranties or reimbursement obligations incurred by El Paso Field
       Services Company up to an amount not to exceed at any time outstanding
       the tangible net worth of El Paso Field Services Company, provided that
       such Debt may be guaranteed by the Company, (D) Excluded Acquisition
       Debt and (E) successive extensions, refinancings or replacements (at the
       same Subsidiary or at any other consolidated Subsidiary of the Company)
       of Debt, Guaranties or reimbursement obligations (or commitments in
       respect thereof) referred to in clauses (A), (B) and (D) above and in an
       amount not in excess of the amounts so extended, refinanced or replaced
       (or the amount of commitments in respect thereof).

              (d)    Sale, Etc. of Assets.  Sell, lease or otherwise transfer,
       or, in the case of the Company, permit any Principal Subsidiary to sell,
       lease or otherwise transfer, (in either case, whether in one transaction
       or in a series of transactions) assets constituting a material portion
       of the consolidated assets of the Company and its Principal Subsidiaries
       taken as a whole, provided that provisions of this subsection (d) shall
       not apply to:

                         (i)  any sale of the San Juan Basin Gathering System
              and related facilities in accordance with the procedures set
              forth in the Master Separation Agreement dated as of January 15,
              1992 between EPNGC, Meridian Oil Holding Inc., a Delaware
              corporation, and Burlington;

                        (ii)  any sale of receivables and related rights
              pursuant to any Alternate Program;

                       (iii)  any Project Financing Subsidiary and the assets
              thereof;

                        (iv)  sales, leases or other transfers of assets or
              capital stock of any Subsidiary of the Company other than any
              Principal Subsidiary;

                         (v)  any sale of Margin Stock;

                        (vi)  any sale of up to 20% of the equity of El Paso
              Field Services Company in an initial public offering of such
              corporation's equity securities;

                       (vii)  any sale, lease or other transfer to the Company
              or any Principal Subsidiary, or to any corporation which after
              giving effect to such transfer will become and be either (A) a
              Principal Subsidiary in
<PAGE>   55
                                                                              50



       which the Company's direct or indirect equity interest will be at least
       as great as its direct or indirect equity interest in the transferor
       immediately prior thereto or (B) a directly or indirectly wholly-owned
       Principal Subsidiary;

                      (viii)  any transfer permitted by Section 5.2(e);

                        (ix)  any transfer to Holding or any of its
              Subsidiaries of any stock or assets other than FERC regulated
              assets (or stock or any other equity interest in an entity owning
              FERC regulated assets) used in the mainline gas transmission
              business; provided that (A) no Event of Default, or event that
              with the giving of notice or lapse of time or both would
              constitute an Event of Default, shall have occurred and be
              continuing before and after giving effect to such transfer and
              (B) no Borrower may be so transferred unless Holding is also a
              Borrower; and

                         (x)  so long as the Tennessee Facility is in effect,
              any sale, lease or other transfer of assets of Tennessee and its
              Subsidiaries, provided that the commitments, if any, outstanding
              under the Tennessee Facility are reduced by an amount equal to
              the net cash proceeds thereof (after provision for taxes,
              holdbacks, reserves and all costs and expenses arising from, or
              attributable to, such transaction) to the extent required under
              the Tennessee Facility.

              (e)    Mergers, Etc.  Merge or consolidate with any person, or
       permit any of its Principal Subsidiaries to merge or consolidate with
       any Person, except that (i) any Principal Subsidiary may merge or
       consolidate with (or liquidate into) any other Subsidiary (other than a
       Project Financing Subsidiary, unless the successor corporation is not
       treated as a Project Financing Subsidiary under this Agreement) or may
       merge or consolidate with (or liquidate into) the Company, provided that
       (A) if such Principal Subsidiary merges or consolidates with (or
       liquidates into) the Company, the Company shall be the continuing or
       surviving corporation and (B) if any such Principal Subsidiary merges or
       consolidates with (or liquidates into) any other Subsidiary of the
       Company, one of such Subsidiaries is the surviving corporation and, if
       either such Subsidiary is not wholly-owned by the Company, such merger
       or consolidation is on an arm's length basis, and (ii) the Company or
       any Principal Subsidiary may merge or consolidate with any other
       corporation (that is, in addition to the Company or any Principal
       Subsidiary of the Company), provided that (A) if the Company merges or
       consolidates with any such other corporation, the Company is the
       surviving corporation, (B) if any Principal Subsidiary merges or
       consolidates with any such other corporation, the surviving
<PAGE>   56
                                                                              51



       corporation is a wholly-owned Principal Subsidiary of the Company, and
       (C) if either the Company or any Principal Subsidiary merges or
       consolidates with any such other corporation, after giving effect to
       such merger or consolidation no Event of Default, and no event which
       with lapse of time or the giving of notice, or both, would constitute an
       Event of Default, shall have occurred and be continuing.

              SECTION 5.3  Reporting Requirements.  So long as any amount
payable by any Borrower hereunder or under any Note shall remain unpaid or any
Lender shall have any Commitment hereunder, the Company will furnish to each
Lender in such reasonable quantities as shall from time to time be requested by
such Lender:

              (a)    as soon as publicly available and in any event within 60
       days after the end of each of the first three fiscal quarters of each
       fiscal year of each of EPNGC and, following its formation, Holding, a
       consolidated balance sheet of each of EPNGC and, following its
       formation, Holding and its respective consolidated subsidiaries as of
       the end of such quarter, and consolidated statements of income and cash
       flows of each of EPNGC and, following its formation, Holding and its
       respective consolidated subsidiaries each for the period commencing at
       the end of the previous fiscal year and ending with the end of such
       quarter, certified (subject to normal year-end adjustments) as being
       fairly stated in all material respects by the chief financial officer,
       controller or treasurer of the Company and accompanied by a certificate
       of such officer stating (i) whether or not such officer has knowledge of
       the occurrence of any Event of Default which is continuing hereunder or
       of any event not theretofore remedied which with notice or lapse of time
       or both would constitute such an Event of Default and, if so, stating in
       reasonable detail the facts with respect thereto, (ii) all relevant
       facts in reasonable detail to evidence, and the computations as to,
       whether or not the Company is in compliance with the requirements set
       forth in subsections (b) and (c) of Section 5.2, and (iii) a listing of
       all Principal Subsidiaries and consolidated Subsidiaries of the Company
       showing the extent of its direct and indirect holdings of their stocks;

              (b)    as soon as publicly available and in any event within 120
       days after the end of each fiscal year of each of EPNGC and, following
       its formation, Holding, a copy of the annual report for such year for
       each of EPNGC and, following its formation, Holding and its respective
       consolidated Subsidiaries containing financial statements for such year
       reported by nationally recognized independent public accountants
       acceptable to the Lenders, accompanied by (i) a report signed by said
       accountants stating that such financial statements have been prepared in
       accordance with
<PAGE>   57
                                                                              52



       generally accepted accounting principles and (ii) a letter from such
       accountants stating that in making the investigations necessary for such
       report they obtained no knowledge, except as specifically stated
       therein, of any Event of Default which is continuing hereunder or of any
       event not theretofore remedied which with notice or lapse of time or
       both would constitute such an Event of Default;

              (c)    within 120 days after the close of each of the Company's
       fiscal years, a certificate of the chief financial officer, controller
       or treasurer of the Company stating (i) whether or not he has knowledge
       of the occurrence of any Event of Default which is continuing hereunder
       or of any event not theretofore remedied which with notice or lapse of
       time or both would constitute such an Event of Default and, if so,
       stating in reasonable detail the facts with respect thereto, (ii) all
       relevant facts in reasonable detail to evidence, and the computations as
       to, whether or not the Company is in compliance with the requirements
       set forth in subsections (b) and (c) of Section 5.2 and (iii) a listing
       of all Principal Subsidiaries and consolidated Subsidiaries of the
       Company showing the extent of its direct and indirect holdings of their
       stocks;

              (d)    promptly after the sending or filing thereof, copies of
       all publicly available reports which the Company, any Principal
       Subsidiary or any Restricted Affiliate sends to any of its security
       holders and copies of all publicly available reports and registration
       statements which the Company, any Principal Subsidiary or any Restricted
       Affiliate files with the Securities and Exchange Commission or any
       national securities exchange other than registration statements relating
       to employee benefit plans and to registrations of securities for selling
       security holders;

              (e)    within 10 days after sending or filing thereof, a copy of
       FERC Form No. 2:  Annual Report of Major Natural Gas Companies, sent or
       filed by the Company to or with the FERC with respect to each fiscal
       year of the Company;

              (f)    promptly in writing, notice of all litigation and of all
       proceedings before any governmental or regulatory agencies against or
       involving the Company, any Principal Subsidiary or any Restricted
       Affiliate, except any litigation or proceeding which in the reasonable
       judgment of the Company (taking into account the exhaustion of all
       appeals) is not likely to have a material adverse effect on the
       consolidated financial condition of the Company and its consolidated
       Subsidiaries taken as a whole;

              (g)    within three Business Days after an executive officer of
       the Company obtains knowledge of the occurrence of any Event of Default
       which is continuing or of any event not theretofore remedied which with
       notice or lapse of time,
<PAGE>   58
                                                                              53



       or both, would constitute an Event of Default, notice of such occurrence
       together with a detailed statement by a responsible officer of the
       Company of the steps being taken by the Company or the appropriate
       Subsidiary to cure the effect of such event;

              (h)    as soon as practicable and in any event (i) within 30 days
       after the Company or any ERISA Affiliate knows or has reason to know
       that any Termination Event described in clause (a) of the definition of
       Termination Event with respect to any Plan has occurred and (ii) within
       10 days after the Company or any ERISA Affiliate knows or has reason to
       know that any other Termination Event has occurred, a statement of the
       chief financial officer or treasurer of the Company describing such
       Termination Event and the action, if any, which the Company or such
       ERISA Affiliate proposes to take with respect thereto;

              (i)    promptly and in any event within two Business Days after
       receipt thereof by the Company or any ERISA Affiliate, copies of each
       notice received by the Company or any ERISA Affiliate from the PBGC
       stating its intention to terminate any Plan or to have a trustee
       appointed to administer any Plan;

              (j)    promptly and in any event within 30 days after the filing
       thereof with the Internal Revenue Service, copies of each Schedule B
       (Actuarial Information) to the annual report (Form 5500 Series) with
       respect to each Single Employer Plan;

              (k)    promptly and in any event within five Business Days after
       receipt thereof by the Company or any ERISA Affiliate from the sponsor
       of a Multiemployer Plan, a copy of each notice received by the Company
       or any ERISA Affiliate concerning (i) the imposition of Withdrawal
       Liability by a Multiemployer Plan, (ii) the determination that a
       Multiemployer Plan is, or is expected to be, in reorganization or
       insolvent within the meaning of Title IV of ERISA, (iii) the termination
       of a Multiemployer Plan within the meaning of Title IV of ERISA, or (iv)
       the amount of liability incurred, or expected to be incurred, by the
       Company or any ERISA Affiliate in connection with any event described in
       clause (i), (ii) or (iii) above; and

              (l)    as soon as practicable but in any event within 60 days of
       any notice of request therefor, such other information respecting the
       financial condition and results of operations of the Company or any
       Subsidiary of the Company as any Lender through the Administrative Agent
       may from time to time reasonably request.

              Each balance sheet and other financial statement furnished
pursuant to subsections (a) and (b) of this Section 5.3
<PAGE>   59
                                                                              54



shall contain comparative financial information which conforms to the
presentation required in Form 10-Q and 10-K, as appropriate, under the
Securities Exchange Act of 1934, as amended.

              SECTION 5.4  Restrictions on Material Subsidiaries.  Upon Holding
becoming a Borrower hereunder, Holding will not, and will not permit any
Material Subsidiary, to enter into any agreement or understanding pursuant to
which (a) any non-equity interest claim Holding may have against any Material
Subsidiary would be subordinate in any manner to the payment of any other
obligation of such Material Subsidiary (other than waivers or subordination of
subrogation, contribution or similar rights under Guaranties and similar
agreements) or (b) by its terms limits or restricts the ability of such
Material Subsidiary to make funds available to Holding (whether by dividend or
other distribution, by replacement of any inter-company advance or otherwise)
if, in any such case referred to in this Section 5.4, there is, at the time any
such agreement is entered into, a reasonable likelihood that all such
agreements and understandings, considered together, would materially and
adversely affect the ability of Holding to meet its obligations as they become
due.


                                   ARTICLE VI

                                   GUARANTEES

              SECTION 6.1  Guarantees.  (a)  Subject to the provisions of
Section 6.1(b), each Borrower hereby unconditionally and irrevocably guarantees
to the Administrative Agent, for the ratable benefit of the Lenders and their
respective successors, indorsees, transferees and assigns, the prompt and
complete payment by each other Borrower when due (whether at the stated
maturity, by acceleration or otherwise) of the Obligations owing by such other
Borrower.

              (b)    Anything in this Article VI to the contrary
notwithstanding, the maximum liability of each Borrower (other than a Borrower
which is guaranteeing the Obligations of its Subsidiaries) under this Article
VI shall in no event exceed the amount which can be guaranteed by such
Borrowing Subsidiary under applicable federal and state laws relating to the
insolvency of debtors.

              (c)    Each Borrower agrees that the Obligations owing by any
other Borrower may at any time and from time to time exceed the amount of the
liability of such other Borrower under this Article VI without impairing the
guarantee of such Borrower under this Article VI or affecting the rights and
remedies of the Administrative Agent or any Lender under this Article VI.

              (d)    No payment or payments made by any Borrower or any other
Person or received or collected by the Administrative Agent
<PAGE>   60
                                                                              55



or any Lender from any Borrower or any other Person by virtue of any action or
proceeding or any set-off or appropriation or application, at any time or from
time to time, in reduction of or in payment of the Obligations shall be deemed
to modify, reduce, release or otherwise affect the liability of the Borrowers
under this Article VI which shall, notwithstanding any such payment or
payments, continue until the Obligations are paid in full and the Commitments
are terminated.

              (e)    Each Borrower agrees that whenever, at any time, or from
time to time, it shall make any payment to the Administrative Agent or any
Lender on account of its liability under this Article VI, it will notify the
Administrative Agent in writing that such payment is made under this Article VI
for such purpose.

              SECTION 6.2  No Subrogation.  Notwithstanding any payment or
payments made by any Borrower under this Article VI or any set-off or
application of funds of such Borrower by the Administrative Agent or any
Lender, such Borrower shall not be entitled to be subrogated to any of the
rights of the Administrative Agent or any Lender against any other Borrower or
against any collateral security or guarantee or right of offset held by the
Administrative Agent or any Lender for the payment of the Obligations, nor
shall such Borrower seek or be entitled to seek any contribution or
reimbursement from any other Borrower in respect of payments made by such
Borrower hereunder, until all amounts owing to the Administrative Agent and the
Lenders by the other Borrowers on account of the Obligations are paid in full
and the Commitments are terminated.  If any amount shall be paid to any
Borrower on account of such subrogation rights at any time when all of the
Obligations shall not have been paid in full, such amount shall be held by such
Borrower in trust for the Administrative Agent and the Lenders, segregated from
other funds of such Borrower, and shall, forthwith upon receipt by such
Borrower, be turned over to the Administrative Agent in the exact form received
by such Borrower (duly indorsed by such Borrower to the Administrative Agent,
if required), to be applied against the Obligations, whether matured or
unmatured, in such order as the Administrative Agent may determine.

              SECTION 6.3  Amendments, etc. with respect to the Obligations;
Waiver of Rights.  Each Borrower shall remain obligated under this Article VI
notwithstanding that, without any reservation of rights against such Borrower,
and without notice to or further assent by such Borrower, any demand for
payment of any of the Obligations made by the Administrative Agent or any
Lender may be rescinded by the Administrative Agent or such Lender, and any of
the Obligations continued, and the Obligations, or the liability of any other
party upon or for any part thereof, or any collateral security or guarantee
therefor or right of offset with respect thereto, may, from time to time, in
whole or in part, be renewed, extended, amended, modified, accelerated,
compromised, waived, surrendered or released by the
<PAGE>   61
                                                                              56



Administrative Agent or any Lender, and this Agreement, any Notes and any other
documents executed and delivered in connection herewith may be amended,
modified, supplemented or terminated, in whole or in part, as the
Administrative Agent (or the Majority Lenders, as the case may be) may deem
advisable from time to time, and any collateral security, guarantee or right of
offset at any time held by the Administrative Agent or any Lender for the
payment of the Obligations may be sold, exchanged, waived, surrendered or
released.  Neither the Administrative Agent nor any Lender shall have any
obligation to protect, secure, perfect or insure any Lien at any time held by
it as security for the Obligations or for this Agreement or any property
subject thereto.  When making any demand hereunder against any Borrower, the
Administrative Agent or any Lender may, but shall be under no obligation to,
make a similar demand on the applicable Borrowing Subsidiaries or any other
guarantor, and any failure by the Administrative Agent or any Lender to make
any such demand or to collect any payments from the other Borrowers or any such
other guarantor or any release of the other Borrowers or such other guarantor
shall not relieve such Borrower of its obligations or liabilities hereunder,
and shall not impair or affect the rights and remedies, express or implied, or
as a matter of law, of the Administrative Agent or any Lender against such
Borrower for the purposes hereof "demand" shall include the commencement and
continuance of any legal proceedings.

              SECTION 6.4  Guarantee Absolute and Unconditional.  Each Borrower
waives any and all notice of the creation, renewal, extension or accrual of any
of the Obligations and notice of or proof of reliance by the Administrative
Agent or any Lender upon this Agreement or acceptance of this Agreement; the
Obligations, and any of them, shall conclusively be deemed to have been
created, contracted or incurred, or renewed, extended, amended or waived, in
reliance upon this Agreement; and all dealings between any Borrower, on the one
hand, and the Administrative Agent and the Lenders, on the other, shall
likewise be conclusively presumed to have been had or consummated in reliance
upon this Agreement.  Each Borrower waives diligence, presentment, protest,
demand for payment and notice of default or nonpayment to or upon the other
Borrowers with respect to the Obligations.  The guarantee contained in this
Article VI shall be construed as a continuing, absolute and unconditional
guarantee of payment without regard to (a) the validity, regularity or
enforceability of this Agreement, any Note, any of the Obligations or any other
collateral security therefor or guarantee or right of offset with respect
thereto at any time or from time to time held by the Administrative Agent or
any Lender, (b) any defense, set-off or counterclaim (other than a defense of
payment or performance) which may at any time be available to or be asserted by
any Borrower against the Administrative Agent or any Lender, or (c) any other
circumstance whatsoever (with or without notice to or knowledge of any
Borrower) which constitutes, or might be construed to constitute, an equitable
or legal discharge of any Borrower for the Obligations, or of the Borrowers
under this
<PAGE>   62
                                                                              57



Agreement, in bankruptcy or in any other instance.  When pursuing its rights
and remedies hereunder against any Borrower, the Administrative Agent and any
Lender may, but shall be under no obligation to, pursue such rights and
remedies as it may have against any other Borrower or any other Person or
against any collateral security or guarantee for the Obligations or any right
of offset with respect thereto, and any failure by the Administrative Agent or
any Lender to pursue such other rights or remedies or to collect any payments
from other Borrowers or any such other Person or to realize upon any such
collateral security or guarantee or to exercise any such right of offset, or
any release of any other Borrower or any such other Person or of any such
collateral security, guarantee or right of offset, shall not relieve any
Borrower of any liability hereunder, and shall not impair or affect the rights
and remedies, whether express, implied or available as a matter of law, of the
Administrative Agent or any Lender against such Borrower.  The guarantees
contained in this Article VI shall remain in full force and effect and be
binding in accordance with and to the extent of its terms upon each Borrower
and its successors and assigns thereof, and shall inure to the benefit of the
Administrative Agent and the Lenders, and their respective successors,
indorsees, transferees and assigns, until all the Obligations and the
obligations of the Borrowers under this Agreement shall have been satisfied by
payment in full and the Commitments shall be terminated, notwithstanding that
from time to time during the term of this Agreement the Borrowers may be free
from any Obligations.

              SECTION 6.5  Reinstatement.  The provisions of this Article VI
shall continue to be effective, or be reinstated, as the case may be, if at any
time payment, or any part thereof, of any of the Obligations is rescinded or
must otherwise be restored or returned by the Administrative Agent or any
Lender upon the insolvency, bankruptcy, dissolution, liquidation or
reorganization of any Borrower or upon or as a result of the appointment of a
receiver, intervenor or conservator of, or trustee or similar officer for, any
Borrower or any substantial part of its property, or otherwise, all as though
such payments had not been made.


                                  ARTICLE VII

                               EVENTS OF DEFAULT

              SECTION 7.1  Event of Default.  If any of the following events
("Events of Default") shall occur and be continuing:

              (a)    Any Borrower shall fail to pay any installment of
       principal of any of its Advances or Notes when due, or any interest on
       any of its Advances or Notes or any other amount payable by it hereunder
       within five Business Days after the same shall be due; or
<PAGE>   63
                                                                              58




              (b)    Any representation or warranty made or deemed made by any
       Borrower herein or by any Borrower (or any of its officers) in
       connection with this Agreement shall prove to have been incorrect in any
       material respect when made or deemed made; or

              (c)    Any Borrower shall fail to perform or observe any other
       term, covenant or agreement contained in this Agreement on its part to
       be performed or observed and any such failure shall remain unremedied
       for 30 days after written notice thereof shall have been given to such
       Borrower by the Administrative Agent or by any Lender with a copy to the
       Administrative Agent; or

              (d)    The Company, any Principal Subsidiary or any Restricted
       Affiliate shall fail to pay any Debt or Guaranty (excluding Debt
       incurred pursuant hereto) of the Company, such Principal Subsidiary or
       such Restricted Affiliate (as the case may be) in an aggregate principal
       amount of $100,000,000 or more, or any installment of principal thereof
       or interest or premium thereon, when due (whether by scheduled maturity,
       required prepayment, acceleration, demand or otherwise) and such failure
       shall continue after the applicable grace period, if any, specified in
       the agreement or instrument relating to such Debt or Guaranty; or any
       other default under any agreement or instrument relating to any such
       Debt, or any other event, shall occur and shall continue after the
       applicable grace period, if any, specified in such agreement or
       instrument, if the effect of such default or event is to accelerate, or
       to permit the acceleration of, the maturity of such Debt; or any such
       Debt shall be required to be prepaid (other than by a regularly
       scheduled required prepayment), prior to the stated maturity thereof, as
       a result of either (i) any default under any agreement or instrument
       relating to any such Debt or (ii) the occurrence of any other event
       (other than an issuance, sale or other disposition of stock or other
       assets, or an incurrence or issuance of Indebtedness or other
       obligations, giving rise to a repayment or prepayment obligation in
       respect of such Debt) the effect of which would otherwise be to
       accelerate or to permit the acceleration of the maturity of such Debt;
       provided that, notwithstanding any provision contained in this
       subsection (d) to the contrary, to the extent that pursuant to the terms
       of any agreement or instrument relating to any Debt or Guaranty referred
       to in this subsection (d) (or in the case of any such Guaranty, relating
       to any obligations Guaranteed thereby), any sale, pledge or disposal of
       Margin Stock, or utilization of the proceeds of such sale, pledge or
       disposal, would result in a breach of any covenant contained therein or
       otherwise give rise to a default or event of default thereunder and/or
       acceleration of the maturity of the Debt or obligations extended
       pursuant thereto, or payment pursuant to any Guaranty, and as a result
       of such
<PAGE>   64
                                                                              59



       terms or of such sale, pledge, disposal, utilization, breach, default,
       event of default or acceleration or nonpayment under such Guaranty, or
       the provisions thereof relating thereto, this Agreement or any Advance
       hereunder would otherwise be subject to the margin requirements or any
       other restriction under Regulation U issued by the Board of Governors of
       the Federal Reserve System, then such breach, default, event of default
       or acceleration, or nonpayment under any Guaranty, shall not constitute
       a default or Event of Default under this subsection (d); or

              (e)(i)  The Company, any Principal Subsidiary or any Restricted
       Affiliate shall (A) generally not pay its debts as such debts become
       due; or (B) admit in writing its inability to pay its debts generally;
       or (C) make a general assignment for the benefit of creditors; or (ii)
       any proceeding shall be instituted or consented to by the Company, any
       Principal Subsidiary or any Restricted Affiliate seeking to adjudicate
       it a bankrupt or insolvent, or seeking liquidation, winding up,
       reorganization, arrangement, adjustment, protection, relief, or
       composition of it or its debts under any law relating to bankruptcy,
       insolvency or reorganization or relief of debtors, or seeking the entry
       of an order for relief or the appointment of a receiver, trustee, or
       other similar official for it or for any substantial part of its
       property; or (iii) any such proceeding shall have been instituted
       against the Company, any Principal Subsidiary or any Restricted
       Affiliate and either such proceeding shall not be stayed or dismissed
       for 60 consecutive days or any of the actions sought in such proceeding
       (including, without limitation, the entry of an order for relief against
       it or the appointment of a receiver, trustee, custodian or other similar
       official for it or any substantial part of its property) shall occur; or
       (iv) the Company, any Principal Subsidiary or any Restricted Affiliate
       shall take any corporate action to authorize any of the actions set
       forth above in this subsection (e); or

              (f)    Any judgment or order of any court for the payment of
       money in excess of $50,000,000 shall be rendered against the Company,
       any Principal Subsidiary or any Restricted Affiliate and either (i)
       enforcement proceedings shall have been commenced by any creditor upon
       such judgment or order (other than any enforcement proceedings
       consisting of the mere obtaining and filing of a judgment lien or
       obtaining of a garnishment or similar order so long as no foreclosure,
       levy or similar process in respect of such lien, or payment over in
       respect of such garnishment or similar order, has commenced) or (ii)
       there shall be any period of 30 consecutive days during which a stay of
       execution or of enforcement proceedings (other than those referred to in
       the parenthesis in clause (i) above) in respect of such judgment or
       order, by reason of a pending appeal, bonding or otherwise, shall not be
       in effect; or
<PAGE>   65
                                                                              60




              (g)    (i) Any Termination Event with respect to a Plan shall
       have occurred and, 30 days after notice thereof shall have been given to
       the Company by the Administrative Agent, such Termination Event shall
       still exist; or (ii) the Company or any ERISA Affiliate shall have been
       notified by the sponsor of a Multiemployer Plan that it has incurred
       Withdrawal Liability to such Multiemployer Plan; or (iii) the Company or
       any ERISA Affiliate shall have been notified by the sponsor of a
       Multiemployer Plan that such Multiemployer Plan is in reorganization, or
       is insolvent or is being terminated, within the meaning of Title IV of
       ERISA; or (iv) any Person shall engage in a "prohibited transaction" (as
       defined in Section 406 of ERISA or Section 4975 of the Code) involving
       any Plan; and in each case in clauses (i) through (iv) above, such event
       or condition, together with all other such events or conditions, if any,
       would result in an aggregate liability of the Company or any ERISA
       Affiliate that would exceed 10% of the Net Worth of the Company.

              (h)    Upon completion of, and pursuant to, a transaction, or a
       series of transactions (which may include prior acquisitions of capital
       stock of EPNGC or Holding in the open market or otherwise), involving a
       tender offer (i) a "person" (within the meaning of Section 13(d) of the
       Securities Exchange Act of 1934) other than Burlington, EPNGC or
       Holding, a Subsidiary of EPNGC or Holding or any employee benefit plan
       maintained for employees of EPNGC or Holding and/or any of their
       respective Subsidiaries or the trustee therefor, shall have acquired
       direct or indirect ownership of and paid for in excess of 50% of the
       outstanding capital stock of EPNGC or Holding entitled to vote in
       elections for directors of EPNGC or Holding and (ii) at any time before
       the later of (A) six months after the completion of such tender offer
       and (B) the next annual meeting of the shareholders of EPNGC or Holding
       following the completion of such tender offer more than half of the
       directors of EPNGC or Holding consists of individuals who (1) were not
       directors before the completion of such tender offer and (2) were not
       appointed, elected or nominated by the Board of Directors in office
       prior to the completion of such tender offer (other than any such
       appointment, election or nomination required or agreed to in connection
       with, or as a result of, the completion of such tender offer); or

              (i)    Any event of default shall occur under any agreement or
       instrument relating to or evidencing any Debt now or hereafter existing
       of the Company or any Principal Subsidiary or Restricted Affiliate as
       the result of any change of control of the Company; or

              (j)    Any of (i) the guarantees contained in Article VI, (ii)
       the Restricted Affiliate Guarantees or (iii) the Holding Guarantee shall
       cease, for any reason, to be in full
<PAGE>   66
                                                                              61



       force and effect or any Borrower, any Restricted Affiliate or Holding
       shall so assert;

then, and in any such event, the Administrative Agent shall at the request, or
may with the consent, of the Majority Lenders, by notice to the Company, (i)
declare the obligation of each Lender to make Advances to be terminated,
whereupon the same shall forthwith terminate, and (ii) declare the Advances and
the Notes, all interest thereon and all other amounts payable under this
Agreement to be forthwith due and payable, whereupon the Advances and the
Notes, all such interest and all such amounts shall become and be forthwith due
and payable, without presentment, demand, protest or further notice of any
kind, all of which are hereby expressly waived by the Borrowers; provided,
however, that if an Event of Default under subsection (e) of this Section 7.1
(except under clause (i)(A) thereof) shall occur, (A) the obligation of each
Lender to make Advances shall automatically be terminated and (B) the Advances
and the Notes, all interest thereon and all other amounts payable under this
Agreement shall automatically become and be forthwith due and payable, without
presentment, demand, protest or any notice of any kind, all of which are hereby
expressly waived by the Borrowers.


                                  ARTICLE VIII

               THE ADMINISTRATIVE AGENT AND THE CAF ADVANCE AGENT

              SECTION 8.1  Authorization and Action.  Each Lender hereby
appoints and authorizes the Administrative Agent and the CAF Advance Agent to
take such action as agent on its behalf and to exercise such powers under this
Agreement as are delegated to the Administrative Agent and the CAF Advance
Agent by the terms hereof, together with such powers as are reasonably
incidental thereto.  As to any matters not expressly provided for by this
Agreement (including, without limitation, enforcement of this Agreement or
collection of the Notes), the Administrative Agent and the CAF Advance Agent
shall not be required to exercise any discretion or take any action, but shall
be required to act or to refrain from acting (and shall be fully protected in
so acting or refraining from acting) upon the instructions of the Majority
Lenders, and such instructions shall be binding upon all Lenders and all
holders of Notes; provided, however, that the Administrative Agent and the CAF
Advance Agent shall not be required to take any action which exposes the
Administrative Agent or the CAF Advance Agent to personal liability or which is
contrary to this Agreement or applicable law.  The Administrative Agent and the
CAF Advance Agent agree to give to each Lender prompt notice of each notice
given to it by any Borrower pursuant to the terms of this Agreement.

              SECTION 8.2  Administrative Agent's and CAF Advance Agent's
Reliance, Etc.  None of the Administrative Agent, the CAF Advance Agent or any
of its respective directors, officers,
<PAGE>   67
                                                                              62



agents or employees shall be liable for any action taken or omitted to be taken
by it or them under or in connection with this Agreement, except for its or
their own gross negligence or willful misconduct.  Without limitation of the
generality of the foregoing, the Administrative Agent and the CAF Advance
Agent:  (i) may treat the payee of any Note as the holder thereof until the
Administrative Agent receives and accepts an Assignment and Acceptance entered
into by the Lender which is the payee of such Note, as assignor, and an
Eligible Assignee, as assignee, as provided in Section 9.7; (ii) may consult
with legal counsel (including counsel for the Company), independent public
accountants and other experts selected by it and shall not be liable for any
action taken or omitted to be taken in good faith by it in accordance with the
advice of such counsel, accountants or experts; (iii) makes no warranty or
representation to any Lender and shall not be responsible to any Lender for any
statements, warranties or representations (whether written or oral) made in or
in connection with this Agreement; (iv) shall not have any duty to ascertain or
to inquire as to the performance or observance of any of the terms, covenants
or conditions of this Agreement on the part of the Borrowers or to inspect the
property (including the books and records) of the Borrowers; (v) shall not be
responsible to any Lender for the due execution, legality, validity,
enforceability, genuineness, sufficiency or value of this Agreement or any
other instrument or document furnished pursuant hereto; and (vi) shall incur no
liability under or in respect of this Agreement by acting upon any notice,
consent, certificate or other instrument or writing (which may be by telegram,
telecopier, cable or telex) believed by it to be genuine and signed or sent by
the proper party or parties.

              SECTION 8.3  Chase and Affiliates.  With respect to its
Commitment, the Advances made by it and the Note issued to it, Chase shall have
the same rights and powers under this Agreement as any other Lender and may
exercise the same as though it were not the Administrative Agent or the CAF
Advance Agent; and the term "Lender" or "Lenders" shall, unless otherwise
expressly indicated, include Chase in its individual capacity.  Chase and its
affiliates may accept deposits from, lend money to, act as trustee under
indentures of, and generally engage in any kind of business with, the Company,
any of its Subsidiaries and any Person who may do business with or own
securities of the Company or any of its Subsidiaries, all as if Chase were not
the Administrative Agent or the CAF Advance Agent and without any duty to
account therefor to the other Lenders.

              SECTION 8.4  Lender Credit Decision.  Each Lender acknowledges
that it has, independently and without reliance upon the Administrative Agent,
the CAF Advance Agent or any other Lender and based on the financial statements
referred to in Section 4.1 and such other documents and information as it has
deemed appropriate, made its own credit analysis and decision to enter into
this Agreement.  Each Lender also acknowledges that it
<PAGE>   68
                                                                              63



will, independently and without reliance upon the Administrative Agent, the CAF
Advance Agent or any other Lender and based on such documents and information
as it shall deem appropriate at the time, continue to make its own credit
decisions in taking or not taking action under this Agreement.

              SECTION 8.5  Indemnification.  The Lenders agree to indemnify the
Administrative Agent and the CAF Advance Agent (to the extent not reimbursed by
the Borrowers), ratably according to the respective principal amounts of the
Advances then outstanding by each of them (or if no Advances are at the time
outstanding or if any Notes are held by Persons which are not Lenders, ratably
according to the respective amounts of their aggregate Commitments), from and
against any and all liabilities, obligations, losses, damages, penalties,
actions, judgments, suits, costs, expenses or disbursements of any kind or
nature whatsoever which may be imposed on, incurred by, or asserted against the
Administrative Agent or the CAF Advance Agent in any way relating to or arising
out of this Agreement or any action taken or omitted by the Administrative
Agent or the CAF Advance Agent under this Agreement, provided that no Lender
shall be liable for any portion of such liabilities, obligations, losses,
damages, penalties, actions, judgments, suits, costs, expenses or disbursements
resulting from the Administrative Agent's or the CAF Advance Agent's gross
negligence or willful misconduct.  Without limitation of the foregoing, each
Lender agrees to reimburse the Administrative Agent and the CAF Advance Agent
promptly upon demand for its ratable share of any out-of-pocket expenses
(including reasonable counsel fees) incurred by the Administrative Agent or the
CAF Advance Agent in connection with the preparation, execution, delivery,
administration, modification, amendment or enforcement (whether through
negotiations, legal proceedings, in bankruptcy or insolvency proceedings, or
otherwise) of, or legal advice in respect of rights or responsibilities under,
this Agreement, to the extent that the Administrative Agent or the CAF Advance
Agent is not reimbursed for such expenses by the Borrowers.

              SECTION 8.6  Successor Administrative Agent and CAF Advance
Agent.  The Administrative Agent and the CAF Advance Agent may resign at any
time by giving written notice thereof to the Lenders and the Company and may be
removed at any time with or without cause by the Majority Lenders.  Upon any
such resignation or removal, the Majority Lenders shall have the right to
appoint a successor Administrative Agent or the CAF Advance Agent.  If no
successor Administrative Agent or CAF Advance Agent shall have been so
appointed by the Majority Lenders, and shall have accepted such appointment,
within 30 days after the retiring Administrative Agent's or the CAF Advance
Agent giving of notice of resignation or the Majority Lenders' removal of the
retiring Administrative Agent or CAF Advance Agent, then such retiring
Administrative Agent or CAF Advance Agent may, on behalf of the Lenders,
appoint a successor Administrative Agent or CAF Advance Agent, which shall be a
Lender and a commercial bank organized,
<PAGE>   69
                                                                              64



or authorized to conduct a banking business, under the laws of the United
States of America or of any State thereof and having a combined capital and
surplus of at least $500,000,000.  Upon the acceptance of any appointment as
Administrative Agent or CAF Advance Agent hereunder by a successor
Administrative Agent or CAF Advance Agent, such successor Administrative Agent
or CAF Advance Agent shall thereupon succeed to and become vested with all the
rights, powers, privileges and duties of the retiring Administrative Agent or
CAF Advance Agent, and the retiring Administrative Agent or CAF Advance Agent
shall be discharged from its duties and obligations under this Agreement.
After any retiring Administrative Agent's or CAF Advance Agent's resignation or
removal hereunder as Administrative Agent or CAF Advance Agent, the provisions
of this Article VII shall inure to its benefit as to any actions taken or
omitted to be taken by it while it was Administrative Agent or CAF Advance
Agent under this Agreement.


                                   ARTICLE IX

                                 MISCELLANEOUS

              SECTION 9.1  Amendments, Etc.  An amendment or waiver of any
provision of this Agreement or the Notes, or a consent to any departure by any
Borrower therefrom, shall be effective against the Lenders and all holders of
the Notes if, but only if, it shall be in writing and signed by the Majority
Lenders, and then such a waiver or consent shall be effective only in the
specific instance and for the specific purpose for which given; provided,
however, that no such amendment, waiver or consent shall, unless in writing and
signed by all the Lenders, be effective to:  (a) waive any of the conditions
specified in Article III, (b) increase or extend the Commitments of the Lenders
or subject the Lenders to any additional obligations, (c) reduce the principal
of, or interest on, any Advance or the Notes or any facility fees hereunder,
(d) postpone any date fixed for any payment of principal of, or interest on,
any Advance or the Notes or any facility fees hereunder, (e) change the
percentage of the Commitments or of the aggregate unpaid principal amount of
any Advance or the Notes, or the number of Lenders, which shall be required for
the Lenders or any of them to take any action under this Agreement, (f) amend
this Section 9.1, (g) amend, waive or consent to any departure of any provision
in Article VI or (h) except as provided below, release any Borrower or Holding
or any Restricted Affiliate from its guarantee in Article VI, the Holding
Guarantee or any Restricted Affiliate Guarantee, as the case may be; provided,
further, that no amendment, waiver or consent shall, unless in writing and
signed by the Administrative Agent and the CAF Advance Agent in addition to the
Lenders required hereinabove to take such action, affect the rights or duties
of the Administrative Agent or the CAF Advance Agent under this Agreement or
any Note; provided, still further, that the guarantee of a Borrower under
Article VI and of a Restricted
<PAGE>   70
                                                                              65



Affiliate under its Restricted Affiliate Guarantee shall be released
automatically upon (i) the sale by the Company of such Borrower or Restricted
Affiliate, provided that such sale is permitted under this Agreement, or (ii)
such Borrower or Restricted Affiliate ceasing to be a Borrower or a Restricted
Affiliate hereunder.

              SECTION 9.2  Notices, Etc.  Except as otherwise provided in
Section 2.2(a), 2.5(d) or 2.15(b), all notices and other communications
provided for hereunder shall be in writing (including telecopier and other
readable communication) and mailed by certified mail, return receipt requested,
telecopied or otherwise transmitted or delivered, if to any Borrower, c/o the
Company at 1 Paul Kayser Center, 100 North Stanton Street, El Paso, Texas
79901, Attention:  Executive Vice President and Chief Financial Officer,
Telecopier:  (915) 541-5008; if to any Lender, at its address set forth under
its name on Schedule I; if to the Administrative Agent, at 270 Park Avenue, New
York, New York  10017, Attention:  John Gehebe, Telecopier:  (212) 270-4892;
and if to the CAF Advance Agent, at 140 East 45th Street, New York, New York
10017, Attention:  Terri Reilly, Telecopier:  (212) 622-0003, Telephone:  (212)
622-8779; or, as to each party and each Borrowing Subsidiary, at such other
address as shall be designated by such party in a written notice to the other
parties.  All such notices and communications shall, if so mailed, telecopied
or otherwise transmitted, be effective when received, if mailed, or when the
appropriate answerback or other evidence of receipt is given, if telecopied or
otherwise transmitted, respectively.  A notice received by the Administrative
Agent, the CAF Advance Agent or a Lender by telephone pursuant to Section
2.2(a), 2.5(d) or 2.15(b) shall be effective if the Administrative Agent or
Lender believes in good faith that it was given by an authorized representative
of the applicable Borrower and acts pursuant thereto, notwithstanding the
absence of written confirmation or any contradictory provision thereof.

              SECTION 9.3  No Waiver; Remedies.  No failure on the part of any
Lender, the Administrative Agent or the CAF Advance Agent to exercise, and no
delay in exercising, any right hereunder or under any Note shall operate as a
waiver thereof; nor shall any single or partial exercise of any right hereunder
or under any Note preclude any other or further exercise thereof or the
exercise of any other right.  The remedies herein provided are cumulative and
not exclusive of any remedies provided by law.

              SECTION 9.4  Costs and Expenses; Indemnity.  (a) Each Borrower
agrees to pay on demand (to the extent not reimbursed by any other Borrower)
(i) all reasonable fees and out-of-pocket expenses of counsel for the
Administrative Agent in connection with the preparation, execution and delivery
of this Agreement, the Notes and the other documents to be delivered hereunder
and the fulfillment or attempted fulfillment of conditions precedent hereunder,
(ii) all reasonable costs and expenses incurred by the
<PAGE>   71
                                                                              66



Administrative Agent and its Affiliates in initially syndicating all or any
portion of the Commitments hereunder, including, without limitation, the
related reasonable fees and out-of-pocket expenses of counsel for the
Administrative Agent or its Affiliates, travel expenses, duplication and
printing costs and courier and postage fees, and excluding any syndication fees
paid to other parties joining the syndicate and (iii) all out-of-pocket costs
and expenses, if any, incurred by the Administrative Agent, the CAF Advance
Agent and the Lenders in connection with the enforcement (whether through
negotiations, legal proceedings in bankruptcy or insolvency proceedings, or
otherwise) of this Agreement, the Notes and the other documents to be delivered
hereunder and thereunder, including the reasonable fees and out-of-pocket
expenses of counsel.

              (b)    If any payment of principal of, or Conversion of, any
Eurodollar Rate Advance or CAF Advance is made by any Borrower to or for the
account of a Lender on any day other than the last day of the Interest Period
for such Advance, as a result of a prepayment pursuant to Section 2.15 or a
Conversion pursuant to Section 2.13(f) or Section 2.14 or due to acceleration
of the maturity of the Advances and the Notes pursuant to Section 7.1 or due to
any other reason attributable to such Borrower, or if any Borrower shall fail
to make a borrowing of Eurodollar Rate Advances or CAF Advances after such
Borrower has given a notice requesting the same in accordance with the
provisions of this Agreement, such Borrower shall, upon demand by such Lender
(with a copy of such demand to the Administrative Agent), pay to the
Administrative Agent for the account of such Lender any amounts required to
compensate such Lender for any additional losses, costs or expenses which it
may reasonably incur as a result of such payment, Conversion or failure to
borrow, including, without limitation, any loss (excluding loss of anticipated
profits), cost or expense incurred by reason of the liquidation or reemployment
of deposits or other funds acquired by any Lender to fund or maintain such
Advance.

              (c)    Each Borrower agrees to indemnify and hold harmless the
Administrative Agent, the CAF Advance Agent and each Lender (to the extent not
reimbursed by any other Borrower) from and against any and all claims, damages,
liabilities and expenses (including, without limitation, fees and disbursements
of counsel) which may be incurred by or asserted against the Administrative
Agent, the CAF Advance Agent or such Lender in connection with or arising out
of any investigation, litigation, or proceeding (whether or not the
Administrative Agent, the CAF Advance Agent or such Lender is party thereto)
related to any acquisition or proposed acquisition by the Company, or by any
Subsidiary of the Company, of all or any portion of the stock or substantially
all the assets of any Person or any use or proposed use of the Advances by any
Borrower (excluding any claims, damages, liabilities or expenses incurred by
reason of the gross negligence or willful misconduct of the party to be
indemnified or its employees or agents, or by reason of any use or disclosure
<PAGE>   72
                                                                              67



of information relating to any such acquisition or use or proposed use of the
proceeds by the party to be indemnified or its employees or agents).

              SECTION 9.5  Right of Set-Off.  Upon the declaration of the
Advances and the Notes as due and payable pursuant to the provisions of Section
7.1, each Lender is hereby authorized at any time and from time to time, to the
fullest extent permitted by law, to set off and apply any and all deposits
(general or special, time or demand, provisional or final) at any time held and
other indebtedness at any time owing by such Lender to or for the credit or the
account of the applicable Borrower against any and all of the obligations of
such Borrower now or hereafter existing under this Agreement and the Notes of
such Borrower held by such Lender, irrespective of whether or not such Lender
shall have made any demand under this Agreement or such Notes and although such
obligations may be unmatured.  Each Lender agrees promptly to notify the
Company after any such set-off and application made by such Lender, provided
that the failure to give such notice shall not affect the validity of such
set-off and application.  The rights of each Lender under this Section 9.5 are
in addition to other rights and remedies (including, without limitation, other
rights of set-off) which such Lender may have.

              SECTION 9.6  Binding Effect.  This Agreement shall become
effective in accordance with the provisions of Section 3.1, and thereafter
shall be binding upon and inure to the benefit of the Borrowers, the
Administrative Agent, the CAF Advance Agent and each Lender and their
respective successors and assigns, except that no Borrower shall have the right
to assign its rights or obligations hereunder or any interest herein without
the prior written consent of all of the Lenders.

              SECTION 9.7  Assignments and Participations.  (a) Each Lender may
assign to one or more banks or other financial institutions all or a portion of
its rights and obligations under this Agreement (including, without limitation,
all or a portion of its Commitment, the Advances owing to it and the Notes held
by it); provided, however, that (i) each such assignment shall be of a
constant, and not a varying, percentage of all rights and obligations under
this Agreement, (ii) the amount of the Commitment of the assigning Lender being
assigned pursuant to each such assignment (determined as of the date of the
Assignment and Acceptance with respect to such assignment) shall in no event be
less than $15,000,000 (or, if less, the entire Commitment of the assigning
Lender) and shall be an integral multiple of $1,000,000, (iii) each such
assignment shall be to an Eligible Assignee, and (iv) the parties to each such
assignment shall execute and deliver to the Administrative Agent, for its
acceptance and recording in the Register, an Assignment and Acceptance,
together with any Notes subject to such assignment and a processing and
recordation fee of $2,500, and shall send to the Company an executed
counterpart of such Assignment and
<PAGE>   73
                                                                              68



Acceptance.  Upon such execution, delivery, acceptance and recording, from and
after the effective date specified in each Assignment and Acceptance, (A) the
assignee thereunder shall be a party hereto and, to the extent that rights and
obligations hereunder have been assigned to it pursuant to such Assignment and
Acceptance, have the rights and obligations of a Lender hereunder and (B) the
assigning Lender thereunder shall, to the extent that rights and obligations
hereunder have been assigned by it pursuant to such Assignment and Acceptance,
relinquish its rights and be released from its obligations under this Agreement
(and, in the case of an Assignment and Acceptance covering all or the remaining
portion of an assigning Lender's rights and obligations under this Agreement,
such Lender shall cease to be a party hereto).

              (b)    By executing and delivering an Assignment and Acceptance,
each Lender assignor thereunder and the assignee thereunder confirm to and
agree with each other and the other parties hereto as follows:  (i) other than
as provided in such Assignment and Acceptance, such assigning Lender makes no
representation or warranty and assumes no responsibility with respect to any
statements, warranties or representations made in or in connection with this
Agreement or the execution, legality, validity, enforceability, genuineness,
sufficiency or value of this Agreement or any other instrument or document
furnished pursuant hereto; (ii) such assigning Lender makes no representation
or warranty and assumes no responsibility with respect to the financial
condition of each Borrower or the performance or observance by each Borrower of
any of its obligations under this Agreement or any other instrument or document
furnished pursuant hereto; (iii) such assignee confirms that it has received a
copy of this Agreement, together with copies of the financial statements
referred to in Section 4.1 and such other documents and information as it has
deemed appropriate to make its own credit analysis and decision to enter into
such Assignment and Acceptance; (iv) such assignee will, independently and
without reliance upon the Administrative Agent, the CAF Advance Agent, such
assigning Lender or any other Lender and based on such documents and
information as it shall deem appropriate at the time, continue to make its own
credit decisions in taking or not taking action under this Agreement; (v) such
assignee confirms that it is an Eligible Assignee; (vi) such assignee appoints
and authorizes the Administrative Agent and the CAF Advance Agent to take such
action as agent on its behalf and to exercise such powers under this Agreement
as are delegated to the Administrative Agent and the CAF Advance Agent by the
terms hereof, together with such powers as are reasonably incidental thereto;
and (vii) such assignee agrees that it will perform in accordance with their
terms all of the obligations which by the terms of this Agreement are required
to be performed by it as a Lender.

              (c)    The Administrative Agent shall maintain at its address
referred to in Section 9.2 a copy of each Assignment and
<PAGE>   74
                                                                              69



Acceptance delivered to and accepted by it and a register for the recordation
of the names and addresses of the Lenders and the Commitment of, and principal
amount of the Advances owing to, each Lender from time to time (the
"Register").  The entries in the Register shall be conclusive and binding for
all purposes, absent manifest error, and each Borrower, the Administrative
Agent, the CAF Advance Agent and the Lenders may treat each Person whose name
is recorded in the Register as a Lender hereunder for all purposes of this
Agreement.  The Register shall be available for inspection by any Borrower or
any Lender at any reasonable time and from time to time upon reasonable prior
notice.  Upon the acceptance of any Assignment and Acceptance for recordation
in the Register, Schedule I hereto shall be deemed to be amended to reflect the
revised Commitments of the Lenders parties to such Assignment and Acceptance as
well as administrative information with respect to any new Lender as such
information is recorded in the Register.

              (d)    Upon its receipt of an Assignment and Acceptance executed
by an assigning Lender and as assignee representing that it is an Eligible
Assignee, together with any Notes subject to such assignment, the
Administrative Agent shall, if such Assignment and Acceptance has been
completed and is in substantially the form of Exhibit G hereto, (i) accept such
Assignment and Acceptance, (ii) record the information contained therein in the
Register and (iii) give prompt notice thereof to the Company; within five
Business Days after its receipt of such notice and its receipt of an executed
counterpart of such Assignment and Acceptance, the Borrowers, at their own
expense, shall execute and deliver to the Administrative Agent in exchange for
the surrendered Notes, if any, new Notes to the order of such Eligible
Assignee, if requested, in an amount equal to the Commitment assumed by it
pursuant to such Assignment and Acceptance and, if the assigning Lender has
retained a Commitment hereunder, new Notes, if requested, to the order of the
assigning Lender in an amount equal to the Commitment retained by it hereunder.
Such new Notes, if any, shall be in an aggregate principal amount equal to the
aggregate principal amount of such surrendered Notes, if any, shall be dated
(A) in the case of Notes made by EPNGC, the Closing Date and (B) in the case of
Notes made by any other Borrower, the date such other Borrower executes and
delivers its Joinder Agreement, and shall otherwise be in substantially the
form of Exhibit A.

              (e)    Each Lender may sell participations to one or more banks
or other entities in or to all or a portion of its rights and obligations under
this Agreement (including, without limitation, all or a portion of its
Commitment, and the Advances owing to it and the Notes held by it); provided,
however, that (i) such Lender's obligations under this Agreement (including,
without limitation, its Commitment to the Borrowers hereunder) shall remain
unchanged, (ii) such Lender shall remain solely responsible to the other
parties hereto for the performance of such obligations, (iii) such Lender shall
remain the holder of
<PAGE>   75
                                                                              70



any such Notes for all purposes of this Agreement, (iv) the Borrowers, the
Administrative Agent, the CAF Advance Agent and the other Lenders shall
continue to deal solely and directly with such Lender in connection with such
Lender's rights and obligations under this Agreement, (v) such Lender shall
continue to be able to agree to any modification or amendment of this Agreement
or any waiver hereunder without the consent, approval or vote of any such
participant or group of participants, other than modifications, amendments and
waivers which (A) postpone any date fixed for any payment of, or reduce any
payment of, principal of or interest on such Lender's Advances or Notes or any
facility fees payable under this Agreement, or (B) increase the amount of such
Lender's Commitment in a manner which would have the effect of increasing the
amount of a participant's participation, or (C) reduce the interest rate
payable under this Agreement and such Lender's Notes, or (D) consent to the
assignment or the transfer by any Borrower of any of its rights and obligations
under the Agreement, and (vi) except as contemplated by the immediately
preceding clause (v), no participant shall be deemed to be or to have any of
the rights or obligations of a "Lender" hereunder.

              (f)    Any Lender may, in connection with any assignment or
participation or proposed assignment or participation pursuant to this Section
9.7, disclose to the assignee or participant or proposed assignee or
participant, any information relating to the Borrowers furnished to such Lender
by or on behalf of the Borrowers; provided that, prior to any such disclosure,
the assignee or participant or proposed assignee or participant shall agree in
writing for the benefit of the Borrowers to preserve the confidentiality of any
confidential information relating to the Borrowers received by it from such
Lender in a manner consistent with Section 9.8.

              (g)    Anything in this Agreement to the contrary
notwithstanding, any Lender may at any time create a security interest in all
or any portion of its rights under this Agreement (including, without
limitation, the Advances owing to it) and the Notes issued to it hereunder in
favor of any Federal Reserve Bank in accordance with Regulation A of the Board
of Governors of the Federal Reserve System (or any successor regulation) and
the applicable operating circular of such Federal Reserve Bank.

              SECTION 9.8  Confidentiality.  Each Lender, the Administrative
Agent and the CAF Advance Agent (each, a "Party") agrees that it will use its
best efforts not to disclose, without the prior consent of the Company (other
than to its, or its Affiliate's, employees, auditors, accountants, counsel or
other representatives, whether existing at the date of this Agreement or any
subsequent time), any information with respect to the Borrowers which is
furnished pursuant to this Agreement, provided that any Party may disclose any
such information (i) as has become generally available to the public, (ii) as
may be required or appropriate in any report, statement or testimony submitted
to
<PAGE>   76
                                                                              71



any municipal, state or Federal regulatory body having or claiming to have
jurisdiction over such party or to the Board of Governors of the Federal
Reserve System or the Federal Deposit Insurance Corporation or similar
organizations (whether in the United States or elsewhere) or their successors,
(iii) as may be required or appropriate in response to any summons or subpoena
or in connection with any litigation or regulatory proceeding, (iv) in order to
comply with any law, order, regulation or ruling applicable to such party, or
(v) to any prospective assignee or participant in connection with any
contemplated assignment of any rights or obligations hereunder, or any sale of
any participation therein, by such Party pursuant to Section 9.7, if such
prospective assignee or participant, as the case may be, executes an agreement
with the Company containing provisions substantially similar to those contained
in this Section 9.8; provided, however, that the Company acknowledges that the
Administrative Agent has disclosed and may continue to disclose such
information as the Administrative Agent in its sole discretion determines is
appropriate to the Lenders from time to time.

              SECTION 9.9  Consent to Jurisdiction.  (a) Each Borrower hereby
irrevocably submits to the jurisdiction of any New York State or Federal court
sitting in New York City and any appellate court from any thereof in any action
or proceeding by the Administrative Agent, the CAF Advance Agent, any Lender or
the holder of any Note in respect of, but only in respect of, any claims or
causes of action arising out of or relating to this Agreement or the Notes
(such claims and causes of action, collectively, being "Permitted Claims"), and
each Borrower hereby irrevocably agrees that all Permitted Claims may be heard
and determined in such New York State court or in such Federal court.  Each
Borrower hereby irrevocably waives, to the fullest extent it may effectively do
so, the defense of an inconvenient forum to the maintenance of such action or
proceeding in any aforementioned court in respect of Permitted Claims.  Each
Borrower hereby irrevocably appoints CT Corporation System (the "Process
Agent"), with an office on the date hereof at 1633 Broadway, New York, New York
10019, as its agent to receive on behalf of such Borrower and its property
service of copies of the summons and complaint and any other process which may
be served by the Administrative Agent, any Lender or the holder of any Note in
any such action or proceeding in any aforementioned court in respect of
Permitted Claims.  Such service may be made by delivering a copy of such
process to the Company by courier and by certified mail (return receipt
requested), fees and postage prepaid, both (i) in care of the Process Agent at
the Process Agent's above address and (ii) at the Company's address specified
pursuant to Section 9.2, and each Borrower hereby irrevocably authorizes and
directs the Process Agent to accept such service on its behalf.  Each Borrower
agrees that a final judgment in any such action or proceeding shall be
conclusive and may be enforced in other jurisdictions by suit on the judgment
or in any other manner provided by law.
<PAGE>   77
                                                                              72



              (b)    Nothing in this Section 9.9 (i) shall affect the right of
any Lender, the holder of any Note or the Administrative Agent or the CAF
Advance Agent to serve legal process in any other manner permitted by law or
affect any right otherwise existing of any Lender, the holder of any Note or
the Administrative Agent or the CAF Advance Agent to bring any action or
proceeding against any Borrower or its property in the courts of other
jurisdictions or (ii) shall be deemed to be a general consent to jurisdiction
in any particular court or a general waiver of any defense or a consent to
jurisdiction of the courts expressly referred to in subsection (a) above in any
action or proceeding in respect of any claim or cause of action other than
Permitted Claims.

              SECTION 9.10  GOVERNING LAW.  THIS AGREEMENT AND THE NOTES SHALL
BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW
YORK.

              SECTION 9.11  Rate of Interest.  It is the intention of the
parties hereto that each Lender shall each conform strictly to usury laws
applicable to it.  Accordingly, if the transactions contemplated hereby would
be usurious as to any Lender under laws applicable to it, then, in that event,
notwithstanding anything to the contrary in this Agreement or in the Notes to
the order of such Lender, it is agreed as follows:  (a) the aggregate of all
consideration which constitutes interest under law applicable to such Lender
that is contracted for, taken, reserved, charged or received by such Lender
hereunder, or under such Notes or otherwise, shall under no circumstances
exceed the maximum amount allowed by such applicable law, and any excess shall
be credited by such Lender on the principal amount of the sums owed to such
Lender (or, if all amounts owing to such Lender shall have been paid in full,
refunded by such Lender to the applicable Borrower); or (b) in the event that a
prepayment of any Advances owed to any Lender is required, then such
consideration that constitutes interest under law applicable to such Lender may
never include more than the maximum amount allowed by such applicable law, and
excess interest, if any, provided for shall be cancelled automatically by such
Lender as of the date of such prepayment and, if theretofore paid, shall be
credited by such Lender on the principal amount of such prepayment obligation
(or, if the principal amount of such prepayment obligation shall have been paid
in full, refunded by such Lender to the applicable Borrower).  To the extent
that Article 5069-1.04 of the Texas Revised Civil Statutes is relevant to any
Lender for the purpose of determining the maximum amount of interest allowed by
applicable law, such Lender hereby elects to determine the applicable rate
ceiling under such Article by the indicated (weekly) rate ceiling from time to
time in effect, subject to such Lender's right subsequently to change such
method in accordance with applicable law.  In no event, however, shall Article
5069, Chapter 15, of the Texas Revised Civil Statutes apply to this Agreement
or the Notes or the transactions contemplated hereby.
<PAGE>   78
                                                                              73




              SECTION 9.12  Effect on Outstanding CAF Advances.  The parties
hereto acknowledge and agree that upon the effectiveness of this Agreement all
"CAF Advances" under the Existing Facilities immediately before the
effectiveness of this Agreement will be converted to CAF Advances hereunder on
terms and conditions set forth in this Agreement.

              SECTION 9.13  Execution in Counterparts.  This Agreement may be
executed in any number of counterparts and by different parties hereto in
separate counterparts, each of which when so executed shall be deemed to be an
original and all of which taken together shall constitute one and the same
agreement.  Delivery to the Administrative Agent of a counterpart executed by a
Lender shall constitute delivery of such counterpart to all of the Lenders.
This Agreement may be delivered by facsimile transmission of the relevant
signature pages hereof.
<PAGE>   79
                                                                              74



              IN WITNESS WHEREOF, the parties hereto have caused this Agreement
to be executed by their respective officers thereunto duly authorized, as of
the date first above written.



                                        EL PASO NATURAL GAS COMPANY



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE CHASE MANHATTAN BANK, as
                                          Administrative Agent, CAF Advance
                                          Agent and a Lender



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        ABN-AMRO BANK, N.V. HOUSTON AGENCY
                                        By:  ABN AMRO North America, Inc.
                                             as agent



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        AUSTRALIA AND NEW ZEALAND BANKING
                                          GROUP LIMITED



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        BANK OF AMERICA ILLINOIS



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   80
                                                                              75



                                        BANK OF MONTREAL



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE BANK OF NEW YORK



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE BANK OF NOVA SCOTIA



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE BANK OF TOKYO-MITSUBISHI, LTD.



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        BANQUE NATIONALE DE PARIS, HOUSTON
                                          AGENCY



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        BARCLAYS BANK PLC



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   81
                                                                              76




                                        BAYERISCHE VEREINSBANK AG,
                                          LOS ANGELES AGENCY



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        CAISSE NATIONALE DE CREDIT AGRICOLE



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        CANADIAN IMPERIAL BANK OF COMMERCE



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        CITIBANK, N.A.



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        COMMERZBANK AKTIENGESELLSCHAFT,
                                          ATLANTA AGENCY



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   82
                                                                              77




                                        CREDIT LYONNAIS NEW YORK BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        CREDIT SUISSE



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE DAI-ICHI KANGYO BANK, LTD.



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        DEUTSCHE BANK AG NEW YORK AND/OR
                                          CAYMAN ISLANDS BRANCHES



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   83
                                                                              78




                                        DRESDNER BANK AG, NEW YORK BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE FIRST NATIONAL BANK OF BOSTON



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE FIRST NATIONAL BANK OF CHICAGO



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE FUJI BANK, LIMITED-HOUSTON
                                          AGENCY



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE INDUSTRIAL BANK OF JAPAN TRUST
                                          COMPANY


                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   84
                                                                              79




                                        KREDIETBANK N.V., GRAND CAYMAN
                                          BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE LONG-TERM CREDIT BANK OF JAPAN,
                                          LTD.



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        MELLON BANK, N.A.



                                        By:                                     
                                           -------------------------------------
                                           Title:




                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        MORGAN GUARANTY TRUST COMPANY OF
                                          NEW YORK



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        NATIONAL WESTMINSTER BANK PLC NEW
                                          YORK BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   85
                                                                              80




                                        NATIONAL WESTMINSTER BANK PLC
                                          NASSAU BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        NATIONSBANK OF TEXAS, N.A.



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        NORINCHUKIN BANK, NEW YORK BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        PNC BANK, NATIONAL ASSOCIATION



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        ROYAL BANK OF CANADA



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE SAKURA BANK, LIMITED - NEW YORK
                                          BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   86
                                                                              81




                                        THE SANWA BANK LIMITED DALLAS
                                          AGENCY



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        SOCIETE GENERALE



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE SUMITOMO BANK, LIMITED, HOUSTON
                                          AGENCY



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE TOKAI BANK, LIMITED, NEW YORK
                                          BRANCH



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        TORONTO DOMINION (TEXAS), INC.



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   87
                                                                              82




                                        UNION BANK OF SWITZERLAND, HOUSTON
                                          AGENCY



                                        By:                                     
                                           -------------------------------------
                                           Title:



                                        By:                                     
                                           -------------------------------------
                                           Title:


                                        THE YASUDA TRUST & BANKING, CO.,
                                          LTD.



                                        By:                                     
                                           -------------------------------------
                                           Title:
<PAGE>   88
                                                                      SCHEDULE I


                          COMMITMENTS, ADDRESSES, ETC.



<TABLE>
<CAPTION>
Name and Address of Lender                     Amount of Commitment
--------------------------                     --------------------
<S>                                                 <C>
The Chase Manhattan Bank                            $31,875,000
One Chase Manhattan Plaza
New York, New York  10017
Attention:   Peter Ling
Telephone:   212-532-1687
Telecopier:  212-270-4892

ABN AMRO Bank, N.V. Houston Agency                  $7,500,000
Three Riverway, Suite 1700
Houston, Texas  77056
Attention:   H. Gene Shiels
Telephone:   713-964-3326
Telecopier:  713-629-7533

Australia and New Zealand                           $7,500,000
Banking Group Limited
1177 Avenue of the Americas
New York, New York  10036
Attention:   Kyle Loughlin
Telephone:   212-801-9853
Telecopier:  212-801-9131

Bank of America Illinois                            $23,437,500
231 South LaSalle
Chicago, Illinois  60697
Attention:   Gloria Turner
Telephone:   312-828-4575
Telecopier:  312-974-9626

Bank of Montreal                                    $23,437,500
700 Louisiana, Suite 4400
Houston, Texas  77002
Attention:   Jane Wiley
Telephone:   713-546-9744
Telecopier:  713-223-4007

The Bank of New York                                $23,437,500
One Wall Street, 19th Floor
New York, New York  10286
Attention:   Nina Russo
Telephone:   212-635-7921
Telecopier:  212-635-7923
</TABLE>
<PAGE>   89
                                                                               2


<TABLE>
<CAPTION>
Name and Address of Lender                     Amount of Commitment
--------------------------                     --------------------
<S>                                                 <C>
The Bank of Nova Scotia                             $23,437,500
Atlanta Agency
600 Peachtree Street, N.E.
Suite 2700
Atlanta, Georgia  30308
Attention:   F.C.H. Ashby
Telephone:   404-877-1500
Telecopier:  404-888-8998

With a copy to:

Houston Representative Office
1100 Louisiana, Suite 3000
Houston, Texas  77002
Attention:   Jamie Conn
Telephone:   713-752-0900
Telecopier:  713-752-2425

The Bank of Tokyo-Mitsubishi, Ltd.                  $23,437,500
1100 Louisiana, Suite 2800
Houston, Texas  77002
Attention:   Michael Meiss
Telephone:   713-655-3815
Telecopier:  713-655-3855

Banque Nationale de Paris,                          $12,187,500
Houston Agency
333 Clay, Suite 3400
Houston, Texas  77002
Attention:   Mike Shryock
Telephone:   713-951-1224
Telecopier:  713-659-1414

Barclays Bank PLC                                   $23,437,500
222 Broadway
New York, New York  10038
Attention:   Director -
  Structured Finance
Telephone:   212-412-7570
Telecopier:  212-412-7511

Bayerische Vereinsbank AG,                          $7,500,000
 Los Angeles Agency
800 Wilshire Blvd., Suite 1600
Los Angeles, California  90017
Attention:   John Carlson,
  Jarunee Hanpachern
Telephone:   213-629-1821
Telecopier:  213-622-6341
</TABLE>
<PAGE>   90
                                                                               3


<TABLE>
<CAPTION>
Name and Address of Lender                     Amount of Commitment
--------------------------                     --------------------
<S>                                                 <C>
Caisse Nationale de Credit Agricole                 $7,500,000
55 East Monroe Street, Suite 4700
Chicago, Illinois  60303
Attention:   Rosemary Brown
Telephone:   312-917-7420
Telecopier:  312-372-4421

Canadian Imperial Bank of Commerce                  $23,437,500
909 Fannin Street, Suite 1200
Houston, Texas  77010
Attention:   Mark Wolf
Telephone:   713-655-5226
Telecopier:  713-650-3727

Citibank, N.A.                                      $28,125,000
One Court Square
Long Island City, New York  11120
Attention:   Leena Caligiure
Telephone:   718-248-5762
Telecopier:  718-248-4844/4845

Commerzbank Aktiengesellschaft,                     $23,437,500
 Atlanta Agency
1230 Peachtree Street, N.E. Suite 3500
Atlanta, Georgia  30309
Attention:   Dave Suttles/Paul Mahoney
Telephone:   404-888-6500
Telecopier:  404-888-6539

Credit Lyonnais New York Branch                     $23,437,500
1000 Louisiana Street, Suite 5360
Houston, Texas  77002
Attention:   Bernadette Archie
Telephone:   713-753-8723
Telecopier:  713-751-0307

Credit Suisse                                       $23,437,500
633 West 5th Street, 64th Floor
Los Angeles, California  90017
Attention:   Rita Asa
Telephone:   213-955-8284
Telecopier:  213-955-8245

The Dai-Ichi Kangyo Bank, Ltd.                      $12,187,500
One World Trade Center, Suite 4911
New York, New York  10048
Attention:   Tina Brucculeri
Telephone:   212-432-6643
Telecopier:  212-912-1879
</TABLE>
<PAGE>   91
                                                                               4


<TABLE>
<CAPTION>
Name and Address of Lender                     Amount of Commitment
--------------------------                     --------------------
<S>                                                 <C>
Deutsche Bank AG New York and/                      $7,500,000
  or Cayman Islands Branches
31 West 52nd Street
New York, New York  10019
Attention:   Stephan A. Wiedemann
Telephone:   212-469-8663
Telecopier:  212-469-8212

Dresdner Bank AG, New York Branch                   $12,187,500
75 Wall Street
New York, New York  10005
Attention:   Charles Lin
Telephone:   212-429-2608
Telecopier:  212-429-2129

First National Bank of Boston                       $7,500,000
100 Federal Street
Mailstop 01-08-02
Boston, Massachusetts  02106
Attention:   Virginia Ryan
Telephone:   617-434-3606
Telecopier:  617-434-3652

The First National Bank of Chicago                  $23,437,500
One First National Plaza
0634, 1FNP, 10
Chicago, Illinois  60670
Attention:   Yvette Thompkins
Telephone:   312-732-1395
Telecopier:  312-732-4840

The Fuji Bank, Limited-Houston Agency               $23,437,500
One Houston Center, Suite 4100
1221 McKinney Street
Houston, Texas  77010
Attention:   Charles vanRavenswaay
Telephone:   713-650-7829
Telecopier:  713-759-0048

The Industrial Bank of Japan                        $12,187,500
 Trust Company
Allen Three Center
333 Clay, Suite 4850
Houston, Texas  77002
Attention:   W. Lynn Williford
Telephone:   713-651-9444
Telecopier:  713-651-9209
</TABLE>
<PAGE>   92
                                                                               5


<TABLE>
<CAPTION>
Name and Address of Lender                     Amount of Commitment
--------------------------                     --------------------
<S>                                                 <C>
Kredietbank N.V., Grand Cayman Branch               $12,187,500
125 West 55th Street
New York, New York  10019
Attention:   Lynda Resuma
Telephone:   212-541-0657
Telecopier:  212-956-5580
or
Attention:   Mayra Ramirez
Telephone:   212-541-0658
Telecopier:  212-956-5580

The Long-Term Credit Bank of Japan, Ltd.            $23,437,500
165 Broadway
New York, New York  10006
Attention:   Bob Pacifici
Telephone:   212-335-4801
Telecopier:  212-608-3452

With a copy to:

2200 Ross Avenue, Suite 4700 West
Dallas, Texas  75201
Attention:   Doug Whiddon
Telephone:   214-969-5352
Telecopier:  214-969-5357

Mellon Bank, N.A.                                   $23,437,500
1100 Louisiana, Suite 3600
Houston, Texas  77002
Attention:   Janet Jenkins
Telephone:   713-759-3040
Telecopier:  713-650-3409

Morgan Guaranty Trust Company of                    $23,437,500
 New York
c/o J.P. Morgan Services, Inc.
500 Stanton Christiana Road
Newark, Delaware  19713
Attention:   Nancy K. Dunbar
Telephone:   302-634-4220
Telecopier:  302-634-1094

National Westminster Bank Plc                       $12,187,500
NatWest Markets
New York Branch
175 Water Street, 19th Floor
New York, New York  10038
Attention:   Commercial Lending Unit
Telephone:   212-602-4180
Telecopier:  212-602-4118
</TABLE>
<PAGE>   93
                                                                               6


<TABLE>
<CAPTION>
Name and Address of Lender                     Amount of Commitment
--------------------------                     --------------------
<S>                                                 <C>
Nationsbank of Texas, N.A.                          $23,437,500
700 Louisiana, 8th Floor
Houston, Texas  77002
Attention:   Patrick M. Delaney
Telephone:   713-247-7373
Telecopier:  713-247-6568

Norinchukin Bank, New York Branch                   $12,187,500
245 Park Avenue, 29th Floor
New York, New York
Attention:   Shinichi Saitoh
Telephone:   212-949-7188
Telecopier:  212-697-5754

PNC Bank, National Association                      $23,437,500
One PNC Plaza
249 Fifth Avenue, 3rd Floor
Pittsburgh, Pennsylvania  15222
Attention:   Thomas K. Grundman/
  Tina Lanuka
Telephone:   412-762-3025/412-762-4826
Telecopier:  412-762-2571/412-762-2571

Royal Bank of Canada                                $23,437,500
600 Wilshire Boulevard, Suite 800
Los Angeles, California  90017
Attention:   Doug Frost
Telephone:   213-955-5310
Telecopier:  213-955-5350

The Sakura Bank, Limited -                          $12,187,500
 New York Branch
277 Park Avenue, 45th Floor
New York, New York  11209
Attention:   David Speir
Telephone:   212-756-6778
Telecopier:  212-888-7651

The Sanwa Bank Limited Dallas Agency                $12,187,500
2200 Ross Avenue, Suite 4100W
Dallas, Texas  75201
Attention:   Robert Smith
Telephone:   214-665-0222
Telecopier:  214-741-6535

Societe Generale                                    $23,437,500
Trammell Crow Center
2001 Ross Avenue, Suite 4800
Dallas, Texas  75201
Attention:   Angela Aldridge
Telephone:   214-979-2792
Telecopier:  214-754-0171
</TABLE>
<PAGE>   94
                                                                               7


<TABLE>
<CAPTION>
Name and Address of Lender                     Amount of Commitment
--------------------------                     --------------------
<S>                                                 <C>
The Sumitomo Bank, Limited,                         $23,437,500
 Houston Agency
700 Louisiana Street, Suite 1750
Houston, Texas  77002
Attention:   Robert Quezada
Telephone:   713-238-8221
Telecopier:  713-238-8291

The Tokai Bank, Limited, New York Branch            $7,500,000
Energy Finance Group
55 East 52nd Street
New York, New York  10055
Attention:   Caralie Olsen
Telephone:   212-339-1163
Telecopier:  212-754-2170

Toronto Dominion (Texas), Inc.                      $23,437,500
909 Fannin Street, 17th Floor
Houston, Texas   77010
Attention:   Lisa Allison
Telephone:   713-653-8244
Telecopier:  713-951-9921

Union Bank of Switzerland,                          $23,437,500
 Houston Agency
1100 Louisiana, Suite 4500
Houston, Texas  77002
Attention:   Evans Swann
Telephone:   713-655-6500
Telecopier:  713-655-6555

The Yasuda Trust & Banking, Co., Ltd.               $12,187,500
666 Fifth Avenue, Suite 801
New York, New York  10103
Attention:   Eric N. Pelletier
Telephone:   212-373-5734
Telecopier:  212-373-5796
</TABLE>
<PAGE>   95
                                                                       EXHIBIT A




                                  FORM OF NOTE



$____________                                                 New York, New York
                                                              ________ ___, 1996


       FOR VALUE RECEIVED, the undersigned, ___________________, a ________
corporation (the "Borrower"), hereby unconditionally promises to pay to the
order of ________________ (the "Lender") at the office of The Chase Manhattan
Bank, located at 270 Park Avenue, New York, New York 10017, in lawful money of
the United States of America and in same day funds, on the Termination Date the
principal amount of (a) _______________ DOLLARS ($__________), or, if less, (b)
the aggregate unpaid principal amount of all Revolving Credit Advances made by
the Lender to the Borrower pursuant to subsection 2.1 of the Credit Agreement,
as hereinafter defined.  The Borrower further agrees to pay interest in like
money at such office on the unpaid principal amount hereof from time to time
outstanding at the rates and on the dates specified in the Credit Agreement.

       The holder of this Note is authorized to, and prior to any transfer
hereof shall, endorse on the schedules attached hereto and made a part hereof
or on a continuation thereof which shall be attached hereto and made a part
hereof the date, Type and amount of each Revolving Credit Advance made pursuant
to subsection 2.1 of the Credit Agreement and the date and amount of each
payment or prepayment of principal thereof, each continuation thereof, each
conversion of all or a portion thereof to another Type and, in the case of
Eurodollar Rate Advances, the length of each Interest Period with respect
thereto.  Each such endorsement shall constitute prima facie evidence of the
accuracy of the information endorsed.  The failure to make any such endorsement
shall not affect the obligations of the Borrower in respect of such Revolving
Credit Advance.

       This Note (a) is one of the Notes referred to in the $750,000,000
Revolving Credit and Competitive Advance Facility Agreement, dated as of
November 4, 1996 (as amended, supplemented or otherwise modified from time to
time, the "Credit Agreement"), among El Paso Natural Gas Company, the Lender,
the other banks and financial institutions from time to time parties thereto
and The Chase Manhattan Bank, as Administrative Agent and CAF Advance Agent,
(b) is subject to the provisions of the Credit Agreement and (c) is subject to
optional and mandatory prepayment in whole or in part as provided in the Credit
Agreement.

<PAGE>   96
                                                                             A-2

       Upon the occurrence of any one or more of the Events of Default, all
amounts then remaining unpaid on this Note shall become, or may be declared to
be, immediately due and payable, all as provided in the Credit Agreement.

       All parties now and hereafter liable with respect to this Note, whether
maker, principal, surety, guarantor, endorser or otherwise, hereby waive
presentment, demand, protest and all other notices of any kind except those
expressly required under the Credit Agreement.

       Unless otherwise defined herein, terms defined in the Credit Agreement
and used herein shall have the meanings given to them in the Credit Agreement.

       THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.


                                        [BORROWER]



                                        By                                      
                                          --------------------------------------
                                          Title:
<PAGE>   97
                                                              Schedule A to Note


           ADVANCES, CONVERSIONS AND REPAYMENTS OF BASE RATE ADVANCES


<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
                                                                       Amount of Base
                                     Amount           Amount of         Rate Advances
                                  Converted to       Principal of       Converted to     Unpaid Principal
             Amount of Base        Base Rate          Base Rate        Eurodollar Rate    Balance of Base     Notation
   Date      Rate Advances          Advances       Advances Repaid        Advances         Rate Advances      Made By
------------------------------------------------------------------------------------------------------------------------
   <S>       <C>                  <C>              <C>                 <C>               <C>                  <C>
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   98
                                                              Schedule B to Note


 ADVANCES, CONTINUATIONS, CONVERSIONS AND REPAYMENTS OF EURODOLLAR RATE ADVANCES


<TABLE>
<CAPTION>
                                                                                     Amount of
                                            Interest Period       Amount of       Eurodollar Rate    Unpaid Principal
           Amount of     Amount Converted    and Eurodollar      Principal of    Advances Converted     Balance of
        Eurodollar Rate    to Eurodollar   Rate with Respect   Eurodollar Rate      to Base Rate      Eurodollar Rate     Notation
  Date     Advances        Rate Advances        Thereto        Advances Repaid       Advances            Advances         By Made
------------------------------------------------------------------------------------------------------------------------------------
 <S>     <C>               <C>              <C>                 <C>               <C>                  <C>                <C>
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                          
</TABLE>
<PAGE>   99
                                                                       EXHIBIT B


                                    FORM OF
                              NOTICE OF BORROWING


The Chase Manhattan Bank, as Administrative Agent
  for the Lenders parties
  to the Credit Agreement
  referred to below
270 Park Avenue
New York, New York  10017
                                                                     [Date]

Attention:  El Paso Natural Gas Company


Ladies and Gentlemen:

              The undersigned, EL PASO NATURAL GAS COMPANY, refers to the
$750,000,000 Revolving Credit and Competitive Advance Facility Agreement, dated
as of November 4, 1996 (the "Credit Agreement", the terms defined therein being
used herein as therein defined), among the undersigned, certain Lenders parties
thereto and The Chase Manhattan Bank, as Administrative Agent and CAF Advance
Agent for said Lenders, and hereby gives you notice, irrevocably, pursuant to
Section 2.2 of the Credit Agreement that the undersigned hereby requests a
Borrowing under the Credit Agreement, and in that connection sets forth below
the information relating to such Borrowing (the "Proposed Borrowing") as
required by Section 2.2(a) of the Credit Agreement:

                (i)  The Borrower for the Proposed Borrowing is ______________.

               (ii)  The Business Day of the Proposed Borrowing is ___________,
       199_.

              (iii)  The Type of Advances comprising the Proposed Borrowing is
       [Base Rate Advances] [Eurodollar Rate Advances].

               (iv)  The aggregate amount of the Proposed Borrowing is
       $__________.

                (v)  The Interest Period for each Eurodollar Rate Advance made
       as part of the Proposed Borrowing is [______ month[s]].

              The undersigned hereby certifies that the following statements
are true on the date hereof, and will be true on the date of the Proposed
Borrowing, before and immediately after giving effect thereto and to the
application of the proceed therefrom:
<PAGE>   100
                                                                             B-2


              (A)    each representation and warranty contained in Section 4.1
       is correct in all material respects as though made on and as of such
       date; and

              (B)    no event has occurred and is continuing, or would result
       from such Proposed Borrowing, which constitutes an Event of Default or
       would constitute an Event of Default but for the requirement that notice
       be given or time elapse or both.


                                        Very truly yours,

                                        EL PASO NATURAL GAS COMPANY



                                        By                                      
                                          --------------------------------------
                                          Title:
<PAGE>   101
                                                                       EXHIBIT C

                                    FORM OF
                               CAF ADVANCE REQUEST



                                                               __________, 199__

The Chase Manhattan Bank, as CAF Advance Agent
270 Park Avenue
New York, New York  10017

              Reference is made to the $750,000,000 Revolving Credit and
Competitive Advance Facility Agreement, dated as of November 4, 1996, among the
undersigned, the Lenders named therein and The Chase Manhattan Bank, as
Administrative Agent and CAF Advance Agent (as the same may be amended,
supplemented or otherwise modified from time to time, the "Credit Agreement").
Terms defined in the Credit Agreement and used herein shall have the meanings
given to them in the Credit Agreement.

              This is a [Fixed Rate] [LIBO Rate] CAF Advance Request* pursuant
to Section 2.5 of the Credit Agreement requesting quotes for the following CAF
Advances:


<TABLE>
  ====================================================================================================
                                               Loan 1                 Loan 2                Loan 3
  ----------------------------------------------------------------------------------------------------
  <S>                                       <C>                    <C>                    <C>
  Aggregate Principal Amount                $__________            $__________            $_________
  ----------------------------------------------------------------------------------------------------
  CAF Advance Date
  ----------------------------------------------------------------------------------------------------
  Maturity Date
  ----------------------------------------------------------------------------------------------------
  Interest Payment Dates
  ====================================================================================================
</TABLE>

                                        Very truly yours,

                                        [BORROWER]


                                        By                            
                                          ----------------------------
                                          Name:
                                          Title:





---------------
*      Pursuant to the Credit Agreement, a CAF Advance Request may be
       transmitted in writing, by telecopy, or by telephone, immediately
       confirmed by telecopy.  In any case, a CAF Advance Request shall contain
       the information specified in the second paragraph of this form.
<PAGE>   102
                                                                       EXHIBIT D

                                     FORM OF
                                CAF ADVANCE OFFER

                                                              ___________, 199__

The Chase Manhattan Bank, as CAF Advance Agent
270 Park Avenue
New York, New York  10017

              Reference is made to the $750,000,000 Revolving Credit and
Competitive Advance Facility Agreement, dated as of November 4, 1996, among the
undersigned, the Lenders named therein and The Chase Manhattan Bank, as
Administrative Agent and CAF Advance Agent (as the same may be amended,
supplemented or otherwise modified from time to time, the "Credit Agreement").
Terms defined in the Credit Agreement and used herein shall have the meanings
given to them in the Credit Agreement.

              In accordance with Section 2.5 of the Credit Agreement, the
undersigned Lender offers to make CAF Advances thereunder in the following
amounts with the following maturity dates:

================================================================================

CAF Advance Date: __________, 199__           Aggregate Maximum Amount: $_______

================================================================================

Maturity Date 1:  __________, 199__           Maximum Amount: $__________
                                              $________ offered at _______*
                                              $________ offered at _______*

================================================================================

Maturity Date 2:  __________, 199__           Maximum Amount: $__________
                                              $________ offered at _______*
                                              $________ offered at _______*

================================================================================

Maturity Date 3:  __________, 199__           Maximum Amount: $__________
                                              $________ offered at _______*
                                              $________ offered at _______*

================================================================================

                                        Very truly yours,

                                        [NAME OF CAF ADVANCE LENDER]


                                        By                           
                                          ---------------------------
                                          Name:
                                          Title:
                                          Telephone No.:
                                          Telecopy No.:





---------------

*      Insert the interest rate offered for the specified CAF Advance.  In the
       case of LIBO Rate CAF Advances, insert a margin bid.  In the case of
       Fixed Rate CAF Advances, insert a fixed rate bid.
<PAGE>   103
                                                                       EXHIBIT E


                                    FORM OF
                            CAF ADVANCE CONFIRMATION



                                                              _________ __, 199_



The Chase Manhattan Bank, as CAF Advance Agent
270 Park Avenue
New York, New York  10017

              Reference is made to the $750,000,000 Revolving Credit and
Competitive Advance Facility Agreement, dated as of November 4, 1996, among the
undersigned, the Lenders named therein, and The Chase Manhattan Bank, as
Administrative Agent and CAF Advance Agent(as the same may be amended,
supplemented or otherwise modified from time to time, the "Credit Agreement").
Terms defined in the Credit Agreement and used herein shall have the meanings
given to them in the Credit Agreement.

              In accordance with Section 2.5(d) of the Credit Agreement, the
undersigned accepts and confirms the offers by the CAF Advance Lender(s) to
make CAF Advances to the undersigned on __________, 199_ [date of CAF Advance
Borrowing] under Section 2.5(d) in the (respective) amount(s) set forth on the
attached list of CAF Advances offered.


                                        Very truly yours,          
                                                                   
                                        [BORROWER]                 
                                                                   
                                                                   
                                        By                         
                                          --------------------------------------
                                          Name:                    
                                          Title:                   


[The Borrower must attach CAF Advance offer list prepared by the CAF Advance
Agent with accepted amount entered by the Borrower to the right of each CAF
Advance offer].
<PAGE>   104
                                                                       EXHIBIT F


                                    FORM OF
                           ASSIGNMENT AND ACCEPTANCE

                           Dated _____________, 199_


              Reference is made to the $750,000,000 Revolving Credit and
Competitive Advance Facility Agreement, dated as of November 4, 1996 (as the
same may be amended or otherwise modified from time to time, the "Credit
Agreement") among EL PASO NATURAL GAS COMPANY, a Delaware corporation (the
"Company"), the Lenders (as defined in the Credit Agreement) and The Chase
Manhattan Bank, as Administrative Agent (the "Administrative Agent") and CAF
Advance Agent (the "CAF Advance Agent") for the Lenders.  Terms defined in the
Credit Agreement are used herein with the same meaning.

              _____________ (the "Assignor") and ____________ (the "Assignee")
agree as follows:

              1.     The Assignor hereby sells and assigns to the Assignee, and
the Assignee hereby purchases and assumes from the Assignor, that interest in
and to all of the Assignor's rights and obligations under the Credit Agreement
as of the date hereof which represents the percentage interest specified on
Schedule 1 of all outstanding rights and obligations under the Credit
Agreement, including, without limitation, such interest in the Assignor's
Commitment, the Advances owing to the Assignor, and the Notes held by the
Assignor.  After giving effect to such sale and assignment, the Assignee's
Commitment and the amount of the Advances owing to the Assignee will be as set
forth in Section 2 of Schedule 1.

              2.     The Assignor (i) represents and warrants that it is the
legal and beneficial owner of the interest being assigned by it hereunder and
that such interest is free and clear of any adverse claim; (ii) makes no
representation or warranty and assumes no responsibility with respect to any
statements, warranties or representations made in or in connection with the
Credit Agreement or the execution, legality, validity, enforceability,
genuineness, sufficiency or value of the Credit Agreement or any other
instrument or document furnished pursuant thereto; (iii) makes no
representation or warranty and assumes no responsibility with respect to the
financial condition of each Borrower or the performance or observance by each
Borrower of any of its obligations under the Credit Agreement or any other
instrument or document furnished pursuant thereto; and (iv) attaches the Notes
referred to in paragraph 1 above and requests that the Administrative Agent
exchange such Notes for new Notes payable to the order of the Assignee in an
amount equal to the Commitment assumed by the Assignee pursuant hereto or new
Notes payable to the order of the Assignee in an amount equal to the Commitment
assumed by the Assignee pursuant hereto and the
<PAGE>   105
                                                                             F-2


Assignor in an amount equal to the Commitment retained by the Assignor under
the Credit Agreement, respectively, as specified on Schedule 1 hereto.

              3.     The Assignee (i) confirms that it has received a copy of
the Credit Agreement, together with copies of the financial statements referred
to in Section 4.1 thereof and such other documents and information as it has
deemed appropriate to make its own credit analysis and decision to enter into
this Assignment and Acceptance; (ii) agrees that it will, independently and
without reliance upon the Administrative Agent, the Assignor or any other
Lender and based on such documents and information as it shall deem appropriate
at the time, continue to make its own credit decisions in taking or not taking
action under the Credit Agreement; (iii) confirms that it is an Eligible
Assignee; (iv) appoints and authorizes the Administrative Agent and CAF Advance
Agent to take such action as agent on its behalf and to exercise such powers
under the Credit Agreement as are delegated to the Administrative Agent and CAF
Advance Agent by the terms thereof, together with such powers as are reasonably
incidental thereto; (v) agrees that it will perform in accordance with their
terms all of the obligations which by the terms of the Credit Agreement are
required to be performed by it as a Lender; [and] (vi) specifies as its address
for notices the address set forth beneath its name on the signature pages
hereof [and (vii) attaches the forms prescribed by the Internal Revenue Service
of the United States certifying as to the Assignee's status for purposes of
determining exemption from United States withholding taxes with respect to all
payments to be made to the Assignee under the Credit Agreement and the Notes or
such other documents as are necessary to indicate that all such payments are
subject to such rates at a rate reduced by an applicable tax treaty]*.

              4.     Following the execution of this Assignment and Acceptance
by the Assignor and the Assignee, it will be delivered to the Administrative
Agent for acceptance and recording by the Administrative Agent.  The effective
date of this Assignment and Acceptance shall be the date of acceptance thereof
by the Administrative Agent, unless otherwise specified on Schedule 1 hereto
(the "Effective Date").

              5.     Upon such acceptance and recording by the Administrative
Agent, as of the Effective Date, (i) the Assignee shall be a party to the
Credit Agreement and, to the extent provided in this Assignment and Acceptance,
have the rights and obligations of Lender thereunder and (ii) the Assignor
shall, to the extent provided in this Assignment and Acceptance, relinquish its
rights and be released from its obligations under the Credit Agreement.





---------------

*      If the Assignee is organized under the laws of a jurisdiction outside
       the United States.
<PAGE>   106
                                                                             F-3


              6.     Upon such acceptance and recording by the Administrative
Agent, from and after the Effective Date, the Administrative Agent shall make
all payments under the Credit Agreement and the Notes in respect of the interest
assigned hereby (including, without limitation, all payments of principal,
interest and commitment fees with respect thereto) to the Assignee.  The
Assignor and Assignee shall make all appropriate adjustments in payments under
the Credit Agreement and the Notes for periods prior to the Effective Date
directly between themselves.

              7.     This Assignment and Acceptance shall be governed by, and
construed in accordance with, the laws of the State of New York.

              IN WITNESS WHEREOF, the parties hereto have caused this
Assignment and Acceptance to be executed by their respective officers thereunto
duly authorized, as of the date first above written, such execution being made
on Schedule 1 hereto.
<PAGE>   107
                                   Schedule 1
                                       to
                           Assignment and Acceptance
                             Dated _________, 199_



Section 1.

       Percentage Interest:                                              ______%

Section 2.

       Assignee's Commitment:                                            $______
       Aggregate Outstanding Principal
         Amount of Advances owing to the Assignee:                       $______


       Note payable to the order of the Assignee
                                                  Dated:           _______, 199_
                                       Principal amount:          $_____________

       Note payable to the order of the Assignor
                                                  Dated:           _______, 199_
                                       Principal amount:          $_____________

Section 3.

       Effective Date*:                                           ________, 199_


[NAME OF ASSIGNEE]                         [NAME OF ASSIGNOR]


By:                                        By:                                  
   ------------------------------             ----------------------------------
Title:                                     Title:
Address for notices:
[Address]


Consented to:

EL PASO NATURAL GAS COMPANY                THE CHASE MANHATTAN BANK, as
                                             Administrative Agent

By:                                        By:                                  
   ------------------------------             ----------------------------------
Title:                                     Title:





---------------

*      This date should be no earlier than the date of acceptance by the
       Administrative Agent.
<PAGE>   108
                                                                               2


       Accepted this __ day
of __________, 199_

THE CHASE MANHATTAN BANK, as
  Administrative Agent


By:                              
   ------------------------------
Title:
<PAGE>   109
                                                                       EXHIBIT G


          FORM OF OPINION OF [ASSOCIATE] GENERAL COUNSEL OF THE COMPANY


                                                            ___________ __, 1996


To Each of the Lenders, the Administrative Agent
  and the CAF Advance Agent
  Referred to Below
c/o The Chase Manhattan Bank
270 Park Avenue
New York, New York  10017

                        Re:  El Paso Natural Gas Company

Ladies and Gentlemen:

              This opinion is furnished to you pursuant to Section 3.2(b)(iii)
of the $750,000,000 Revolving Credit and Competitive Advance Facility
Agreement, dated as of November 4, 1996 (the "Credit Agreement"), among El Paso
Natural Gas Company (the "Borrower"), the banks and other financial
institutions from time to time party thereto (each a "Lender," and together the
"Lenders"), and The Chase Manhattan Bank, as Administrative Agent (in such
capacity, the "Administrative Agent") and as CAF Advance Agent (in such
capacity, the "CAF Advance Agent") for the Lenders.  Unless the context
otherwise requires, all capitalized terms used herein without definition shall
have the meanings ascribed to them in the Credit Agreement.

              I am [Associate] General Counsel of the Borrower, and I, or
attorneys over whom I exercise supervision, have acted as counsel for the
Borrower in connection with the preparation, execution and delivery of the
Credit Agreement.  In that connection, I or such attorneys have examined:

              (1)  the Credit Agreement, executed by the parties thereto;

              (2)  the Notes, executed by the Borrower; and

              (3)  the other documents furnished by the Borrower pursuant to
Sections 3.1 and 3.2 of the Credit Agreement.

              I, or attorneys over whom I exercise supervision, have also
examined the originals, or copies certified to our satisfaction, of the
agreements, instruments and other documents, and all of the orders, writs,
judgments, awards, injunctions and decrees, which affect or purport to affect
the Borrower's ability to perform the Borrower's obligations under the Credit
Agreement or the Notes (collectively referred to herein as the "Documents").
In addition, I, or attorneys over whom I exercise
<PAGE>   110
                                                                             G-2

supervision, have examined the originals, or copies certified to our
satisfaction, of such other corporate records of the Borrower, certificates of
public officials and of officers of the Borrower, and agreements, instruments
and other documents, as I have deemed necessary as a basis for the opinions
hereinafter expressed.  In all such examinations, I, or attorneys over whom I
exercise supervision, have assumed the legal capacity of all natural persons
executing documents, the genuineness of all signatures on original or
certified, conformed or reproduction copies of documents of all parties (other
than, with respect to the Documents, the Borrower), the authenticity of
original and certified documents and the conformity to original or certified
copies of all copies submitted to such attorneys or me as conformed or
reproduction copies.  As to various questions of fact relevant to the opinions
expressed herein, I have relied upon, and assume the accuracy of,
representations and warranties contained in the Credit Agreement and
certificates and oral or written statements and other information of or from
public officials, officers and/or representatives of the Borrower and others.

              I have assumed that the parties to the Documents other than the
Borrower have the power to enter into and perform such documents and that such
documents have been duly authorized, executed and delivered by, and constitute
legal, valid and binding obligations of, such parties.

              The opinions expressed below are limited to the federal laws of
the United States and, to the extent relevant hereto, the General Corporation
Law of the State of Delaware, as currently in effect.  I assume no obligation
to supplement this opinion if any applicable laws change after the date hereof
or if I become aware of any facts that might change the opinions expressed
herein after the date hereof.

              Based on the foregoing and upon such investigation as we have
deemed necessary, and subject to the limitations, qualifications and
assumptions set forth herein, I am of the following opinion:

              1.     The Borrower (i) is a corporation duly incorporated and
       existing in good standing under the laws of the State of Delaware, and
       (ii) possesses all the corporate powers and all other authorizations and
       licenses necessary to engage in its business and operations as now
       conducted, the failure to obtain or maintain which would have a Material
       Adverse Effect.

              2.     The execution, delivery and performance by the Borrower of
       the Documents are within the Borrower's corporate powers and have been
       duly authorized by all necessary corporate action in respect of or by
       the Borrower, and do not contravene (i) the Borrower's charter or by-
       laws, each as amended to date, (ii) any federal law, rule or regulation
       applicable to the Borrower (excluding provisions of federal law
       expressly referred to in and covered by the
<PAGE>   111
                                                                             G-3

       opinion of Jones, Day, Reavis & Pogue delivered to you in connection
       with the transactions contemplated hereby) or any provision of the
       General Corporation Law or the State of Delaware applicable to the
       Borrower, or (iii) any contractual restriction binding on or affecting
       the Borrower.  The Documents have been duly executed and delivered on
       behalf of the Borrower.

              3.     No authorization or approval or other action by, and no
       notice to or filing with, any federal governmental authority or
       regulatory body (including, without limitation, the FERC) is required
       for the due execution, delivery and performance by the Borrower of the
       Documents, except those required in the ordinary course of business in
       connection with the performance by the Borrower of its obligations under
       certain covenants and warranties contained in the Documents.

              4.     To the best of my knowledge, there is no action, suit or
       proceeding pending or overtly threatened against or involving the
       Borrower or any of the Principal Subsidiaries which, in my reasonable
       judgment (taking into account the exhaustion of all appeals), would have
       a material adverse effect upon the consolidated financial condition of
       the Borrower and its consolidated Subsidiaries taken as a whole, or
       which purports to affect the legality, validity, binding effect or
       enforceability of any Document.

              These opinions are given as of the date hereof and are solely for
your benefit in connection with the transactions contemplated by the Credit
Agreement.  These opinions may not be relied upon by you for any other purpose
or relied upon by any other person for any purpose without my prior written
consent.


                                        Very truly yours,


<PAGE>   112
                                                                       EXHIBIT H


               FORM OF OPINION OF NEW YORK COUNSEL TO THE COMPANY



                                ______ __, 1996


To Each of the Lenders, the Administrative Agent,
     and the CAF Advance Agent Referred to Below
c/o The Chase Manhattan Bank
270 Park Avenue, 10th Floor
New York, New York  10017


       Re: $750,000,000 Revolving Credit and Competitive Advance Facility
           Agreement dated as of November 4, 1996


Dear Ladies and Gentlemen:

              We have acted as special New York counsel for El Paso Natural Gas
Company, a Delaware corporation (the "Company"), in connection with the
$750,000,000 Revolving Credit and Competitive Advance Facility Agreement, dated
as of November 4, 1996 (the "Financing Agreement"), among the Company, the
banks and other financial institutions from time to time party thereto (each a
"Lender," and together the "Lenders") and The Chase Manhattan Bank, as
Administrative Agent (in such capacity, the "Administrative Agent") and as CAF
Advance Agent (in such capacity, the "CAF Advance Agent") for the Lenders.
This opinion is delivered to you pursuant to Section 3.2(b)(iv) of the
Financing Agreement.  Capitalized terms used herein and not otherwise defined
have the meanings assigned such terms in the Financing Agreement.  With your
permission, all assumptions and statements of reliance herein have been made
without any independent investigation or verification on our part except to the
extent otherwise expressly stated, and we express no opinion with respect to
the subject matter or accuracy of the assumptions or items upon which we have
relied.

              In connection with the opinions expressed herein, we have
examined such documents, records and matters of law as we have deemed necessary
for the purposes of this opinion.  We have examined, among other documents, the
following:

              (a)    An executed copy of the Financing Agreement; and

              (b)    An executed copy of each of the Notes.

The documents referred to in items (a) and (b) above are referred to herein
collectively as the "Documents."
<PAGE>   113
                                                                             H-2


              In all such examinations, we have assumed the legal capacity of
all natural persons executing documents, the genuineness of all signatures, the
authenticity of original and certified documents and the conformity to original
or certified copies of all copies submitted to us as conformed or reproduction
copies.  As to various questions of fact relevant to the opinions expressed
herein, we have relied upon, and assume the accuracy of, representations and
warranties contained in the Documents and certificates and oral or written
statements and other information of or from representatives of the Company and
others and assume compliance on the part of all parties to the Documents with
their covenants and agreements contained therein.  With respect to the opinions
expressed in paragraph (a) below, our opinions are limited (x) to our actual
knowledge, if any, of the Company's specially regulated business activities and
properties based solely upon an officer's certificate in respect of such
matters and without any independent investigation or verification on our part
and (y) to our review of only those laws and regulations that, in our
experience, are normally applicable to transactions of the type contemplated by
the Documents.

              To the extent it may be relevant to the opinions expressed
herein, we have assumed that the parties to the Documents have the power to
enter into and perform such documents and to consummate the transactions
contemplated thereby and that such documents have been duly authorized,
executed and delivered by, and, except as set forth in paragraph (b) with
respect to the Company, constitute legal, valid and binding obligations of,
such parties.

              Based upon the foregoing, and subject to the limitations,
qualifications and assumptions set forth herein, we are of the opinion that:

       (a)    The execution and delivery to the Administrative Agent, the CAF
Advance Agent and the Lenders by the Company of the Documents and the
performance by the Company of its obligations thereunder (i) do not require
under present law any filing or registration by the Company with, or approval
or consent to the Company of, any governmental agency or authority of the State
of New York that has not been made or obtained except those required in the
ordinary course of business in connection with the performance by the Company
of its obligations under certain covenants and warranties contained in the
Documents and (ii) do not violate any present law, or present regulation of any
governmental agency or authority, of the State of New York applicable to the
Company or its property.

       (b)    The Documents constitute legal, valid and binding obligations of
the Company enforceable against the Company in accordance with their respective
terms.

       (c)    The borrowings by the Company under the Financing Agreement and
the applications of the proceeds thereof as provided in the Financing Agreement
will not violate Regulation
<PAGE>   114
                                                                             H-3

G, T, U or X of the Board of Governors of the Federal Reserve System.

              The opinions set forth above are subject to the following
qualifications:

       (A)    We express no opinion as to:

                     (i)    the validity, binding effect or enforceability (a)
       of any provision of the Documents relating to indemnification,
       contribution or exculpation in connection with violations of any
       securities laws or statutory duties or public policy, or in connection
       with willful, reckless or criminal acts or gross negligence of the
       indemnified or exculpated party or the party receiving contribution; or
       (b) of any provision of any of the Documents relating to exculpation of
       any party in connection with its own negligence that a court would
       determine in the circumstances under applicable law to be unfair or
       insufficiently explicit;

                     (ii)   the validity, binding effect or enforceability of
       (a) any purported waiver, release, variation, disclaimer, consent or
       other agreement to similar effect (all of the foregoing, collectively, a
       "Waiver") by the Company under the Documents to the extent limited by
       provisions of applicable law (including judicial decisions), or to the
       extent that such a Waiver applies to a right, claim, duty, defense or
       ground for discharge otherwise existing or occurring as a matter of law
       (including judicial decisions), except to the extent that such a Waiver
       is effective under and is not prohibited by or void or invalid under
       provisions of applicable law (including judicial decisions), (b) any
       provision of any Document relating to choice of governing law to the
       extent that the validity, binding effect or enforceability of any such
       provision is to be determined by any court other than a court of the
       State of New York or (c) any provision of any Document relating to forum
       selection to the extent the forum is a federal court;

                     (iii)  the enforceability of any provision in the
       Documents specifying that provisions thereof may be waived only in
       writing, to the extent that an oral agreement or an implied agreement by
       trade practice or course of conduct has been created that modifies any
       provision of the Documents;

                     (iv)   the effect of any law of any jurisdiction other
       than the State of New York wherein the Administrative Agent, the CAF
       Advance Agent or any Lender may be located or wherein enforcement of any
       document referred to above may be sought that limits the rates of
       interest legally chargeable or collectible; and
<PAGE>   115
                                                                             H-4

                     (v)    any approval, consent or authorization of the
       Federal Energy Regulatory Commission or any other United States federal
       agency or authority needed in connection with the execution, delivery
       and performance by the Company of the Documents, the consummation of the
       transactions contemplated thereby and compliance with the terms and
       conditions thereof.

       (B)    Our opinions above are subject to (i) applicable bankruptcy,
insolvency, reorganization, fraudulent transfer, voidable preference,
moratorium or similar laws, and related judicial doctrines, from time to time
in effect affecting creditors' rights and remedies generally, (ii) general
principles of equity (including, without limitation, standards of materiality,
good faith, fair dealing and reasonableness, equitable defenses and limits on
the availability of equitable remedies), whether such principles are considered
in a proceeding at law or in equity and (iii) the qualification that certain
other provisions of the Documents may be unenforceable in whole or in part
under the laws (including judicial decisions) of the State of New York or the
United States of America, but the inclusion of such provisions does not affect
the validity as against the Company of the Documents as a whole, and the
Documents contain adequate provisions for enforcing payment of the obligations
governed thereby, subject to the other qualifications contained in this letter.

       (C)    Our opinions as to enforceability are subject to the effect of
generally applicable rules of law that:

              (i)    limit the availability of a remedy under certain
       circumstances when another remedy has been elected; and

              (ii)   may, where less than all of a contract may be
       unenforceable, limit the enforceability of the balance of the contract
       to circumstances in which the unenforceable portion is not an essential
       part of the agreed exchange; and

              (iii)  govern and afford judicial discretion regarding the
       determination of damages and entitlement to attorneys' fees and other
       costs.

       (D)    For the purposes of the opinion set forth in paragraph (c) above,
we have assumed that (i) none of the Administrative Agent, the CAF Advance
Agent or any of the Lenders has or will have the benefit of any agreement or
arrangement (excluding the Documents) pursuant to which any Advances are
directly or indirectly secured by Margin Stock, (ii) none of the Administrative
Agent, the CAF Advance Agent, any of the Lenders or any of their respective
affiliates has extended or will extend any other credit to the Company directly
or indirectly secured by Margin Stock and (iii) none of the Administrative
Agent, the CAF Advance Agent or any of the Lenders has relied or will rely upon
any Margin Stock as collateral in extending or maintaining any Advances
pursuant to the Financing Agreement.
<PAGE>   116
                                                                             H-5

       (E)    For purposes of our opinions above insofar as they relate to the
Company, we have assumed that (i) the Company is a corporation validly existing
in good standing in its jurisdiction of incorporation, has all requisite power
and authority, and has obtained all requisite corporate, shareholder, third
party and governmental authorizations, consents and approvals, and made all
requisite filings and registrations, necessary to execute, deliver and perform
the Documents to which it is a party (except to the extent noted in paragraph
(a) above), and that such execution, delivery and performance will not violate
or conflict with any law, rule, regulation, order, decree, judgment, instrument
or agreement binding upon or applicable to the Company or its properties
(except to the extent noted in paragraph (a) above), and (ii) the Documents
have been duly executed and delivered by the Company.

              The opinions expressed herein are limited to the federal laws of
the United States of America (in the case of the matters covered in paragraph
(c) above) and the laws of the State of New York, as currently in effect,
except that we express no opinion with respect to laws, rules or regulations of
the State of New York, or of any governmental agency or authority thereof,
applicable to companies engaged in the transmission or distribution of gas or
other petroleum products, or as to filings, registrations, approvals or
consents required under or by such laws, rules or regulations.

              We express no opinion as to the compliance or noncompliance, or
the effect of the compliance or noncompliance, of each of the addressees with
any state or federal laws or regulations applicable to each of them by reason
of their status as or affiliation with a federally insured depository
institution.

              The opinions expressed herein are solely for the benefit of the
Administrative Agent, CAF Advance Agent and the Lenders and may not be relied
on in any manner or for any purpose by any other person or entity.



                                      Very truly yours,

                                      JONES, DAY, REAVIS & POGUE



                                      By:                                       
                                         ---------------------------------------
<PAGE>   117
                                                                       EXHIBIT I


                         [Letterhead of Process Agent]



                                                           ______________, 199__



To each of the Lenders parties
  to the Credit Agreement (as
  defined and referred to
  below) and to The Chase Manhattan Bank
  as Administrative Agent and
  CAF Advance Agent for said Lenders
c/o The Chase Manhattan Bank
270 Park Avenue
New York, New York  10017

To El Paso Natural Gas Company
100 North Stanton
El Paso, Texas  79901


                          El Paso Natural Gas Company

Gentlemen:

              Reference is made to that certain $750,000,000 Revolving Credit
and Competitive Advance Facility Agreement, dated as of November 4, 1996 (said
Agreement, as it may hereafter be amended, supplemented or otherwise modified
from time to time, being the "Credit Agreement", the terms defined therein
being used herein with the same meaning) among El Paso Natural Gas Company (the
"Company"), certain banks and other financial institutions from time to time
party thereto as Lenders thereunder (the "Lenders") and The Chase Manhattan
Bank, as Administrative Agent and CAF Advance Agent (in such capacities, the
"Administrative Agent" and the "CAF Advance Agent" for the Lenders).

          Pursuant to Section 9.9(a) of the Credit Agreement ______________
(the "Borrower") has appointed the undersigned (with an office on the date
hereof at 1633 Broadway, New York, New York 10019) as Process Agent to receive
on behalf of the Borrower and its property service of copies of the summons and
complaint and any other process which may be served by the Administrative
Agent, the CAF Advance Agent, any Lender or the holder of any Note in any
action or proceeding by the Administrative Agent, the CAF Advance Agent, any
Lender or the holder of any Note in any New York State or Federal court sitting
in New York City in respect of, but only in respect of, any claims or causes of
action  arising out of or relating to the Credit Agreement and the Notes issued
pursuant thereto.
<PAGE>   118
                                                                             I-2


              The undersigned hereby accepts such appointment as Process Agent
and agrees with each of you that (i) the undersigned will not terminate the
undersigned's agency as such Process Agent prior to June 15, 2002 (and hereby
acknowledges that the undersigned has been paid in full by the Borrower for its
services as Process Agent through such date), (ii) the undersigned will
maintain an office in New York City through such date and will give the
Administrative Agent prompt notice of any change of address of the undersigned,
(iii) the undersigned will perform its duties as Process Agent in accordance
with Section 9.9(a) of the Credit Agreement and (iv) the undersigned will
forward forthwith to the Borrower at its address specified below copies of any
summons, complaint and other process which the undersigned receives in
connection with its appointment as Process Agent.

              This acceptance and agreement shall be binding upon the
undersigned and all successors of the undersigned.


                                        Very truly yours,

                                        CT CORPORATION SYSTEM


                                        By:                                     
                                           -------------------------------------
                                           Title:


Address of the Borrower:

[Address]
<PAGE>   119
                                                                       EXHIBIT J


                                    FORM OF
                               JOINDER AGREEMENT


       Reference is made to the $750,000,000 Revolving Credit and CAF Advance
Facility Agreement, dated as of November 4, 1996 (as amended, supplemented or
otherwise modified from time to time, the "Credit Agreement"; terms defined
therein being used herein as therein defined), among El Paso Natural Gas
Company (the "EPNGC"), certain banks and other financial institutions from time
to time party thereto and The Chase Manhattan Bank, as Administrative Agent and
CAF Advance Agent.

       The undersigned hereby acknowledges that it has received and reviewed a
copy (in execution form) of the Credit Agreement, and agrees to:

       (a)    join the Credit Agreement as a Borrower party thereto;

       (b)    be bound by all covenants, agreements and acknowledgements
              attributable to a Borrower in the Credit Agreement and any Note
              to which it is a party; and

       (c)    perform all obligations required of it by the Credit Agreement
              and any Note to which it is a party.

       The undersigned hereby represents and warrants that the representations
and warranties with respect to it contained in, or made or deemed made by it
in, Article IV of the Credit Agreement are true and correct on the date hereof.

       THIS JOINDER AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED AND
INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.
<PAGE>   120
                                                                             J-2

       IN WITNESS WHEREOF, the undersigned has caused this Joinder Agreement to
be duly executed and delivered in New York, New York by its proper and duly
authorized officer as of this _________ day of ____________, 199__.



                                        [BORROWER]


                                        By:                                     
                                           -------------------------------------
                                           Title:


ACKNOWLEDGED AND AGREED TO:
-------------------------- 

[EL PASO NATURAL GAS COMPANY]
[HOLDING]


By:                              
   ------------------------------
   Title:
<PAGE>   121
                                                                       EXHIBIT K


                         FORM OF OPINION OF [ASSOCIATE]
                         GENERAL COUNSEL OF THE COMPANY



              (a)    [Each of the Company and the Borrowing Subsidiary]
       [Holding] (i) is a corporation duly incorporated and existing in good
       standing under the laws of the jurisdiction of its organization, and
       (ii) possesses all the corporate powers and all other authorizations and
       licenses necessary to engage in its business and operations as now
       conducted, the failure to obtain or maintain which would have a Material
       Adverse Effect.

              (b)    The execution and delivery by [the Company and the
       Borrowing Subsidiary][Holding] of the Joinder Agreement and by [the
       Borrowing Subsidiary][Holding] of the Notes made by it and the
       performance by [the Borrowing Subsidiary][Holding] of its obligations as
       a "Borrower" under the Credit Agreement and the Notes made by it are
       within such corporation's corporate powers and have been duly authorized
       by all necessary corporate action in respect of or by [each of the
       Company and the Borrowing Subsidiary (as applicable)][Holding], and do
       not contravene (i) [the Company's or the Borrowing
       Subsidiary's][Holding's] charter or by-laws, each as amended to date,
       (ii) any federal law, rule or regulation applicable to [the Company or
       the Borrowing Subsidiary][Holding] (excluding provisions of federal law
       expressly referred to in and covered by the opinion of [New York
       Counsel] delivered to you in connection with the transactions
       contemplated hereby) or any provision of the General Corporation Law of
       the State of Delaware applicable to such corporation, or (iii) any
       contractual restriction binding on or affecting [the Company or the
       Borrowing Subsidiary][Holding].  The Joinder Agreement has been duly
       executed and delivered on behalf of [the Company and the Borrowing
       Subsidiary][Holding] and the Notes made by [the Borrowing
       Subsidiary][Holding] have been duly executed and delivered on behalf of
       [the Borrowing Subsidiary][Holding].

              (c)    No authorization or approval or other action by, and no
       notice to or filing with, any federal governmental authority or
       regulatory body (including, without limitation, the FERC) is required
       for (i) the due execution and delivery by [the Company or the Borrowing
       Subsidiary][Holding] of the Joinder Agreement, (ii) the performance by
       [the Borrowing Subsidiary][Holding] of its obligations as a "Borrower"
       under the Credit Agreement or (iii) the execution, delivery and
       performance by [the Borrowing Subsidiary][Holding] of the Notes made by
       it, except those required in the ordinary course of business in
<PAGE>   122
                                                                             K-2

       connection with the performance by [the Company or the Borrowing
       Subsidiary][Holding] of its obligations under certain covenants and
       warranties contained in the Joinder Agreement, the Credit Agreement and
       the Notes and those which have been obtained and are in full force and
       effect.

              (d)    To the best of my best knowledge, there is no action, suit
       or proceeding pending or overtly threatened against or involving the
       Company or any of the Principal Subsidiaries which, in my reasonable
       judgment (taking into account the exhaustion of all appeals), would have
       a material adverse effect upon the consolidated financial condition of
       the Company and its consolidated Subsidiaries taken as a whole, or which
       purports to affect the legality, validity, binding effect or
       enforceability of the Joinder Agreement, the Credit Agreement or the
       Notes.
<PAGE>   123
                                                                       EXHIBIT L


                          FORM OF OPINION OF NEW YORK
                             COUNSEL TO THE COMPANY


              (a)    The execution and delivery to the Administrative Agent,
       the CAF Advance Agent and the Lenders by [the Company and the Borrowing
       Subsidiary][Holding] of the Joinder Agreement and by [the Borrowing
       Subsidiary][Holding] of the Notes made by it and the performance by [the
       Borrowing Subsidiary][Holding] of its obligations as a "Borrower" under
       the Credit Agreement and the Notes made by it (i) do not require under
       present law, any filing or registration by [the Company or the Borrowing
       Subsidiary][Holding] with, or approval or consent to [the Company or the
       Borrowing Subsidiary][Holding] of, any governmental agency or authority
       of the State of New York that has not been made or obtained, except
       those, if any, required in the ordinary course of business in connection
       with the performance by [the Company or the Borrowing
       Subsidiary][Holding] of its respective obligations under certain
       covenants and warranties contained in the Joinder Agreement, the Credit
       Agreement and the Notes and (ii) do not violate any present law, or
       present regulation of any governmental agency or authority, of the State
       of New York applicable to [the Company or the Borrowing
       Subsidiary][Holding] or its property.

              (b)    The Joinder Agreement, the Credit Agreement and the Notes
       (as applicable) constitute the legal, valid and binding obligations of
       [each of the Company and the Borrowing Subsidiary][Holding] enforceable
       against [each of the Company and the Borrowing Subsidiary][Holding] in
       accordance with their respective terms.

              (c)    The borrowings by [the Borrowing Subsidiary][Holding]
       under the Credit Agreement and the applications of the proceeds thereof
       as provided in the Credit Agreement will not violate Regulation G, T, U
       or X of the Board of Governors of the Federal Reserve System.