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Mr. Lamar C. McIntyre
Zapata Corporation
June 29, 1995
Page 2

If this letter accurately reflects our agreement, please execute in the space 
provided below and return one fully-executed original to me as soon as possible.

Very truly yours,

ENTERRA CORPORATION



    /s/ Steven C. Grant
--------------------------------
Steven C. Grant
Senior Vice President
Corporate Development


ACCEPTED AND AGREED TO:

ZAPATA CORPORATION



     /s/ Lamar C. McIntyre
--------------------------------
Lamar C. McIntyre
Chief Financial Officer