<PAGE>
 
[LOGO OF
 NOREX AMERICA, INC.                NOREX AMERICA, INC.
 APPEARS HERE]             P.O. Box HM 429, Hamilton, HM BX, Bermuda
                       Telephone: (809) 293-2058 Telefax: (809) 293-3231

April 10, 1995

Mr. Avram A. Glazer, President and CEO
Zapata Corporation
777 South Post Oak Lane
One Riverway, Suite 2200
Houston, Texas 77056

Dear Avram:

We accept you offer to purchase 2,250,000 shares of Zapata stock at $4.00 per 
share from Norex America, Inc. with the $9,000,000 to be wire transferred upon 
surrender and delivery of the certificates representing such shares. Our share 
certificates are in the process of being couriered to the United States from 
Norway and such certificates are expected to arrive by Wednesday. Our wire 
transfer instructions are as follows:

Correspondent Bank: The Bank of New York, 51 West 51st Street, New York,
                    ABA No. 50000047
         Credit to: NordlandsBanken AS, Oslo, Norway,
                    SWIFT Code: NOBANO 22 OSL
 Further Credit to: Norex America, Inc.
       Account No.: 34766DB0100

Regards,

/s/ SIGNATURE APPEARS HERE

for Kristian Siem

cc: Joe von Rosenberg, III