<PAGE>   4
Documents to the Purchaser.

         (c)     Upon receipt of a certificate signed by the Purchaser and the
Sellers that the Purchase Agreement has been terminated pursuant to Section 11
(a)(i) or a certificate executed by either Purchasers or Sellers that the
Purchase Agreement has been terminated by the Purchaser or Sellers pursuant to
Section 11 (a) (ii), (iii) or (iv) of the Purchase Agreement, the Escrow Agent
shall forthwith (i) disburse to the Sellers, the Sellers' Escrow Documents and
any Distributions held in the Escrow Account, and (ii) disburse to the
Purchaser the Purchaser's Escrow Documents, the Libra Fee together with accrued
interest thereon and the net proceeds from any sale of the Zapata Shares.

         (d)     The trust impressed upon the Escrow Documents and the Libra
Fee by reason of this Agreement shall in all cases cease and all Escrow
Documents and the Libra Fee shall be free of such trust upon being disbursed in
accordance with this Section 2.


                 Section 3.  Certain Covenants.          Purchaser and
Sellers agree that they will not (a) sell or otherwise dispose of, or grant any
option with respect to, any of the Escrow Documents (or any of the securities
evidenced thereby), (b) create or permit to exist any Lien upon or with respect
to any of the Escrow Documents, or (c) take any action or permit any action to
be taken that would invalidate or restrict the transfers contemplated under the
Purchase Agreement of any certificates or instruments representing or
evidencing any or all of the Escrow Documents.

                 Section 4.  Effect of Final Disbursements.  Upon complete
distribution of all Escrow Documents, the Distributions and the Libra Fee as
provided for in Section 2, this Agreement shall terminate (the date upon which
such actions are completed being herein referred to as the "Termination Date")
and you will be relieved of any further duties and responsibility in connection
therewith.

                 Section 5.  Expenses of Escrow Agent.  For your services as
Escrow Agent and depository under this Agreement, as compensation for all
services performed, you will receive a fee of $7,500.00 ("Escrow Fee") at or
about the time of execution of this Agreement by all of the parties hereto and
will be reimbursed for your actual out-of-pocket expenses reasonably incurred
in connection with the established and routine administration of the Escrow
Account.  Such fees and expenses incurred to date will be paid upon execution
of this Agreement and all other subsequent expenses will be paid within five
days of the Termination Date.  Libra shall pay $5,000.00 of the Escrow Fee.
The balance of the Escrow Fee and the reimbursement of the expenses shall be
paid by one-half by the Purchaser and the other one-half paid by the Sellers.
Reimbursement of expenses will be





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