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CONTROL NUMBER  [0000]             MESA INC.        SUBSCRIPTION CERTIFICATE FOR
 
   SUBSCRIPTION CERTIFICATE FOR SHARES OF SERIES A 8% CUMULATIVE CONVERTIBLE
                                PREFERRED STOCK
                  VOID IF NOT EXERCISED AT OR BEFORE 5:00 P.M.
            (NEW YORK CITY TIME) JULY 26, 1996, THE EXPIRATION DATE


                         EXPIRATION DATE JULY 26, 1996
                                       
                 THIS SUBSCRIPTION CERTIFICATE IS TRANSFERABLE
                       AND MAY BE DIVIDED AT THE OFFICE
                           OF THE SUBSCRIPTION AGENT
                                       
                                       
                                  [        ]
                                    SHARES
                   SUBSCRIPTION PRICE U.S.$2.26 PER SHARE OF
                      SERIES A 8% CUMULATIVE CONVERTIBLE
                                PREFERRED STOCK


THIS SUBSCRIPTION CERTIFICATE MAY BE USED TO
SUBSCRIBE FOR SHARES OR MAY BE ASSIGNED OR SOLD,
FULL INSTRUCTIONS APPEAR ON THE BACK OF THIS
SUBSCRIPTION CERTIFICATE.
 
REGISTERED OWNER                    [OWNER]                    CUSIP 590911 11 1
 
       [0000000000]          [**NUMBER OF RIGHTS**]
 
The registered owner of this Subscription Certificate, named above, or assignee,
is entitled to the number of Rights to subscribe for shares of Series A 8%
Cumulative Convertible Preferred Stock, par value $.01 per share (the "Series A
Preferred Stock"), of MESA Inc. ("Mesa") shown above, in the ratio of one share
of Series A Preferred Stock for each Right, pursuant to the Basic Subscription
Right and upon the terms and conditions and at the price for each Share of
Series A Preferred Stock specified in the Company's Prospectus dated July 3,
1996.
 
If you subscribe for fewer than all the shares represented by his Subscription
Certificate, the Subscription Agent will issue a new Subscription Certificate
representing the balance of the unsubscribed Rights, provided that the
Subscription Agent has received your Subscription Certificate and payment prior
to 5:00 p.m., New York City time, on July 26, 1996. No new Subscription
Certificate will be issued after such date.
 
                IMPORTANT: Complete appropriate form on reverse
 
DATE:  [ __________  , 1996]
 
         [G. Michael Prescott]   MESA INC.     
LOGO     ---------------------   /s/ BOONE PICKENS
               Secretary         ----------------------------------------
                                 Chairman of the Board
                                 Chief Executive Officer
 
                                     [seal]
   2
                   PLEASE FILL IN ALL APPLICABLE INFORMATION
 

                                                                            
TO:       American Stock Transfer & Trust Company                                              Expiration Date: July 26, 1996
          Subscription Agent
          40 Wall Street, 46th Floor
          New York, New York 10005
A.        Basic Subscription Privilege  ------------   x         $2.26       = $ -------
                                      (No. of Shares)        (Subscription
                                                                Price)
B.        Oversubscription Privilege   ------------    x         $2.26       = $ -------(1)
                                      (No. of Shares)        (Subscription
                                                                Price)
C.        Amount of Check Enclosed (or                                       = $ -------
          amount in notice of
          guaranteed
          delivery) payable to MESA
          Inc.
D.        Sell any remaining Rights   / /
E.        Sell all of my Rights       / /
          (1)      The Oversubscription Privilege can be exercised by a holder of Rights only if the Rights held by him are
          exercised to the fullest extent possible.
F.        Name of Soliciting Dealer   / /   Lehman Brothers Inc.
                                      / /   Other: ---------------------------

 
- --------------------------------------------------------------------------------
 
SECTION 1.       TO SUBSCRIBE: I hereby irrevocably subscribe for the number of
shares of Series A Preferred Stock for the price indicated as the total of A and
B hereon upon the terms and conditions specified in the Prospectus related
hereto, receipt of which is acknowledged. I hereby agree that if I fail to pay
for the Shares of Series A Preferred Stock for which I have subscribed, Mesa may
exercise any of the remedies set forth in the Prospectus.
 
                  TO SELL: If I have checked either the box on line D or on line
E, I authorize the sale of Rights by the Dealer Manager according to the
procedures described in the Prospectus.
 
- ------------------------------------------------------------------------
 
- ------------------------------------------------------------------------
Signature of Subscriber(s)
 
- ------------------------------------------------------------------------
Address for delivery of Shares
 
If permanent change of address, check here / /
 
Please give your telephone number: ( )
- ---------------------
 
Tax I.D. Number or Social Security Number:
                                          ------------------------------------
- ------------------------------------------------------------------------------
 
SECTION 2.       TO TRANSFER RIGHTS (except pursuant to D and E above). For
value received,_____________ of the Rights represented by the Subscription 
Certificate are assigned to:
 
- ------------------------------------------------------------------------
                                           (Print Full Name of Assignee)
 
- ------------------------------------------------------------------------
                                           (Print Full Address)
 
- ------------------------------------------------------------------------
                                           Signature(s) of Assignor(s)
 
IMPORTANT:      The signature(s) must correspond in every particular, without
                alteration, with the name(s) as printed on the face of this
                Subscription Certificate.
 
Your signature must be guaranteed by an Eligible Guarantor Institution as
defined in Rule 17Ad-15 of the Securities Exchange Act of 1934.
 
Signature      ----------------------------------------
               (Name of Bank or Firm)
Guaranteed By
               ----------------------------------------
               (Signature of Officer and Title)
 
       PROCEEDS FROM THE SALE OF RIGHTS MAY BE SUBJECT TO WITHHOLDING OF U.S.
TAXES UNLESS THE SELLER'S CERTIFIED U.S. TAXPAYER IDENTIFICATION NUMBER (OR
CERTIFICATE REGARDING FOREIGN STATUS) IS ON FILE WITH THE SUBSCRIPTION AGENT AND
THE SELLER IS NOT OTHERWISE SUBJECT TO U.S. BACKUP WITHHOLDING.