<PAGE>
 
     (b) Seller will retain responsibility for and continue to pay all medical,
life insurance, disability and other welfare plan expenses and benefits for each
Zapata Employee with respect to claims incurred by such employees or their
covered dependents under any benefit plan and subject to the terms thereof prior
to the Closing Date. Expenses and benefits with respect to claims incurred by
Continuing Employees or their covered dependents on or after the Closing Date
shall be the responsibility of Purchasers. For purposes of this paragraph, a
claim is deemed incurred when the services that are the subject of the claim are
performed; provided, however, that in the case of life insurance, a claim is
deemed incurred when the death occurs and in the case of long-term disability
benefits, when the disability occurs. With respect to each Zapata Employee who
is not a Continuing Employee or such employee's dependent, the Seller shall be
responsible for health care continuation rights under Section 4980B of the Tax
Code and Sections 601-609 of ERISA for those Zapata Employees. The Purchasers
shall be responsible for all continuation of health coverage rights under
Section 4980B of the Tax Code and Sections 601-609 of ERISA for all Continuing
Employees and their dependents.

     Section 11.3 No Third Party Beneficiaries. No provision of this Article
shall create any third party beneficiary or other rights in any employee or
former employee (including any beneficiary or dependent thereof) of the Seller
in respect to continued employment or resumed employment with either the
Purchasers or Seller and no provision of this Article XI shall create any such
rights in any employee or former employee (including any beneficiary or
dependent thereof) of Seller with respect to any benefits that may be provided
directly or indirectly in any Benefit Plan or other employee benefit plan or
program.

                                  ARTICLE XII.
                                 MISCELLANEOUS

     Section 12.1 Books and Records. Upon consummation of the transactions
provided herein and for a period of five years thereafter, the Seller agrees
that upon the reasonable written request of the Purchasers, the Seller will
provide the Purchasers with access to the tax records (or copies thereof)
retained by the Seller pursuant to this Agreement. All costs and expenses
associated with providing such tax records (or copies thereof) shall be borne by
the Purchasers. Nothing herein shall be deemed to require the Seller to maintain
or refrain from disposing of any books and records transferred pursuant to this
Agreement for any period of time after the Closing Date. However, if Seller
desires to dispose of any such books or records, Seller agrees to give
Purchasers notice of such intention and the opportunity to retain such books and
records, at Purchasers' expense.

     Section 12.2  Accounts Receivable.

     (a) In the event that 90% of the face amount of the accounts receivable
included within the Assets on the Closing Date (the "90% Amount") are not
collected within one hundred twenty (120) days after the Closing Date, then at
the request of Purchasers, the Seller shall pay Enterra Sub an amount equal to
(i) the 90% Amount, (ii) less amounts collected by Purchasers, (iii) less the
allowance for doubtful accounts utilized in the calculation of the Agreed Upon
Net Asset Value.

     (b) For purposes of Section 12.2(a), Purchasers shall use best efforts to
diligently collect all accounts receivable.  All payments received by Purchasers
from any debtor for accounts receivable which are Assets shall be applied first
to the oldest accounts receivable applicable to such debtor, whether owed to
Seller or Purchasers.

     (c) If and when a payment is made by Seller to Enterra Sub pursuant to
Section 12.2(a), upon receipt of such payment Purchasers shall assign to the
Seller making the payment all of its rights with respect to the uncollected
accounts receivables giving rise to the payment and shall also thereafter
promptly remit any excess collections received by Purchasers with respect to
such assigned receivables.  If and when the amount subsequently collected by
Seller with respect to the assigned receivables equals (i) the payment therefor
plus (ii) the costs and expenses reasonably incurred by Seller in the collection
of such assigned receivables, Seller shall reassign to Enterra Sub all of such
assigned receivables as have not been collected in full by Seller and shall also
thereafter promptly

                                       21