<PAGE>
 
         PRELIMINARY COPY -- CONFIDENTIAL, FOR THE INFORMATION OF THE
                    SECURITIES AND EXCHANGE COMMISSION ONLY.

                               ZAPATA CORPORATION
                        1717 St. James Place, Suite 550
                             Houston, Texas  77056
                                 (713) 941-6100

                   NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
                         TO BE HELD NOVEMBER ___, 1995

To the Stockholders of
Zapata Corporation:

  Notice is hereby given that a special meeting (the "Special Meeting") of
stockholders of Zapata Corporation will be held at ____________________________
on November ___, 1995, at 9:00 a.m. local time, for the following purposes:

     1.  To consider and vote upon the sale of the Company's natural gas
  compression business conducted by its wholly owned subsidiaries, Energy
  Industries, Inc. and Zapata Energy Industries, L.P., to Enterra Corporation
  (the "Energy Industries Sale Proposal"), all as more fully described in the
  accompanying Proxy Statement.

     2.  To consider and vote upon the sale of the Company's natural gas
  gathering, processing, marketing and trading business conducted by its wholly
  owned subsidiary, Cimarron Gas Holding Company and its subsidiaries, on such
  terms and conditions as shall be determined by the Board of Directors (the
  "Cimarron Sale Proposal"), all as more fully described in the accompanying
  Proxy Statement.

     3.  To transact such other business incidental to the conduct of the
  Special Meeting or any adjournment(s) or postponement(s) thereof.

  The Board of Directors has fixed the close of business on October 6, 1995 as
the record date for the determination of stockholders entitled to receive notice
of, and to vote at, the Special Meeting and any adjournment(s) or
postponement(s) thereof, and only stockholders of record at said time and on
said date are entitled to notice of, and to vote at, the Special Meeting.

  THE BOARD OF DIRECTORS RECOMMENDS THAT THE STOCKHOLDERS VOTE FOR THE ENERGY
INDUSTRIES SALE PROPOSAL AND FOR THE CIMARRON SALE PROPOSAL.

  Stockholders are cordially invited to attend the Special Meeting in person.
Those who will not attend and who wish their shares voted are requested to sign,
date and mail promptly the enclosed proxy, for which a stamped return envelope
is provided.

                              By Order of the Board of Directors,



                              JOSEPH L. von ROSENBERG, III
                              Vice President, General Counsel
                              and Corporate Secretary
Houston, Texas
October ___, 1995

WHETHER OR NOT YOU INTEND TO BE PRESENT AT THE SPECIAL MEETING, YOU ARE URGED TO
PROMPTLY COMPLETE, SIGN AND MAIL THE ENCLOSED PROXY IN THE ACCOMPANYING
ENVELOPE.