<PAGE>

                                                                    EXHIBIT 4(e)
 
                              NOREX AMERICA, INC.
                               P. O. Box HM 429
                            Hamilton, HMBX, Bermuda

                                 March 7, 1995

Zapata Corporation
Attention: Chief Financial Officer
One Riverway, Suite 2200
777 South Post Oak Lane
Houston, Texas 77056

   Re:  $17,500,000 Aggregate Principal Amount 8.5% Unsecured Exchangeable
        Notes Due 1996 of Zapata Corporation

Gentlemen:

  The purpose of this letter is to reflect the terms of the consent by Norex  
America, Inc. ("Norex"), as holder of all of the above outstanding Notes (the 
"Notes"), (i) as to certain prepayments which may be made on the Notes by Zapata
Corporation (the "Company") using proceeds from the sale by the Company of the 
673,077 shares of TDW Stock (as defined in the Notes) which the Company is 
currently prohibited from selling pursuant to Section 4.B. of the Notes (the 
"Restricted Shares") and (ii) as to a cash tender offer to be made by the 
Company to all common stockholders of the Company.

Prepayments on the Notes

  Notwithstanding the provisions of Section 4.B. and Section 6 of the Notes, 
Norex agrees that the Company may, from time to time, sell Restricted Shares to 
parties who are not affiliated with either the Company or any officer, director
or principal stockholder of the Company at prices equal to their fair market 
value

 at the respective times of such sales, provided that the net proceeds from
such sales are paid by the purchasers, of such Restricted Shares directly to 
Norex or Norex's designee in accordance with the payment instructions issued by 
Norex to the Company with respect to the Notes in effect at the respective times
of such sales. In addition, the broker handling each such sale shall be 
instructed to deliver to Norex or Norex's designee a copy of the confirmation of
the trade showing the net proceeds payable therefrom.