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                                                                   EXHIBIT 10.40
 

                           CHARTWELL INVESTMENTS INC.
                                717 Fifth Avenue
                                   23rd Floor
                            New York, New York 10022


                                January 30, 1997


Petro Stopping Centers, L.P.
6080 Surety Drive
El Paso, Texas 79905
Attention:     President

Dear Sirs:

     This letter is to confirm our agreement that in connection with the
transactions (the "Transactions") contemplated in the Omnibus Agreement dated as
of October 18, 1996 by and among James A. Cardwell and James A. Cardwell, Jr.
and affiliates, Petro Holdings GP Corp., a Delaware corporation, Petro Holdings
LP Corp., a Delaware corporation, Mobil Long Haul Inc., a Delaware corporation,
and Petro Stopping Centers, L.P., a Delaware limited partnership, you have
agreed to reimburse us at the Closing of the Transactions for the reasonable
out-of-pocket costs and expenses which we have incurred in connection with the
Transactions.  You have also agreed to pay us a fee for advisory services we
have rendered to you in connection with the financing of the Transactions (the
"Financing") at the Closing equal to: (a) one percent (1%) of total
capitalization of Petro Stopping Centers, L.P., a Delaware limited partnership
and its affiliates ("Petro), including, without limitation, all debt facilities,
preferred and common equity interests, but excluding the $30 million expansion
credit facility (the "Expansion Facility"); plus (b) one half percent (1/2%) of
the Expansion Facility (collectively, the "Advisory Fee").

     These services are attributable to acting as exclusive financial advisor
with respect to the Transactions and the Financing and negotiating and assisting
with the documentation related to the Financing (collectively, the "Advisory
Services").

     Each of the parties hereto acknowledges that the Advisory Services for
which the Advisory Fee is to be paid hereunder have been heretofore rendered by
Chartwell Investments Inc. at your request in connection with the Financing as
described above.

     Petro agrees to indemnify and hold Chartwell Investments Inc., its
officers, employees and agents (each an "Indemnified Party") harmless against
any liability, claim, loss or expenses, as and when incurred ("Damages"), to
which an Indemnified Party may become subject as a result of the performance of
the services described herein; provided, that the Company shall not be liable to
                               --------                                         
an Indemnified Party for Damages resulting primarily and directly from
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Petro Stopping Centers, L.P.
January 30, 1997
Page 2


the Indemnified Party's bad faith, gross negligence or willful misconduct, and
Chartwell Investments Inc. shall so indemnify the New Partners (as defined in
the Omnibus Agreement) for Damages arising from its bad faith, gross negligence
or willful misconduct.

     The benefits of this Agreement shall inure to the respective successors and
assigns of the parties hereto and of the indemnified parties hereunder and their
successors and assigns and representatives, and the obligations and liabilities
assumed hereunder by the parties hereto shall be binding upon their respective
successors and assigns.

     This Agreement shall not be assignable by the parties hereto without mutual
written consent.

     This Agreement shall be subject to and governed by the laws of the State of
Delaware without regard to its conflict of laws principles and rules.

     If the foregoing comports with your understanding of our agreement, please
sign below, whereupon this letter shall be a valid and binding agreement.

                                        Very truly yours,                 
                                                                         
                                        CHARTWELL INVESTMENTS INC.       
                                                                         
                                                                         
                                                                         
                                        By:/s/ Todd Berman
                                           ------------------------------ 
                                        Name:  Todd R. Berman
                                             ----------------------------
                                        Title:  President
                                              ---------------------------    

ACCEPTED AND AGREED AS OF THIS
30th DAY OF January, 1996

PETRO STOPPING CENTERS, L.P.



By:     Larry J. Zine
   ------------------------------
Name:   Larry J. Zine
     ----------------------------
Title: Executive Vice President
      ---------------------------