FOURTH AMENDMENT TO LOAN AGREEMENT


       THIS FOURTH AMENDMENT TO LOAN AGREEMENT (hereinafter called the "Fourth
  Amendment") executed as of the 29th day of March, 1995, by and between
  MAYNARD OIL COMPANY, a Delaware corporation (hereinafter referred to as the
  "Borrower") and BANK ONE, TEXAS, N.A., a national banking association
  (hereinafter referred to as "Lender").

                               W I T N E S S E T H:

       WHEREAS, Borrower and First City, Texas-Dallas ("First City") entered
  into a Credit Agreement dated as of October 1, 1990 (the "Loan Agreement")
  under the terms of which Bank agreed to provide a term loan facility in the
  amount of $10,000,000.00 to Borrower; and

       WHEREAS, Borrower and First City entered into a First Amendment to Loan
  Agreement, dated as of November 19, 1991 (the "First Amendment") amending the
  Loan Agreement in certain respects as therein set forth; and 

       WHEREAS, on October 30, 1992, First City was taken over by the Federal
  Deposit Insurance Corporation ("FDIC") in the FDIC's capacity as receiver;
  and

       WHEREAS, the FDIC, as receiver of First City, assigned to New First
  City, Texas-Dallas, N.A. ("New First City") all of the rights of First City
  in and to the Loan Agreement, First Amendment, note and the liens, security
  interest and other collateral securing same (the "First City Debt"); and

       WHEREAS, as of February 1, 1993, New First City assigned all of its
  right, title and interest in and to the First City Debt to Lender; and

       WHEREAS, Borrower and Lender entered into a Second Amendment to Loan
  Agreement, dated as of February 1, 1993 (the "Second Amendment") amending the
  Loan Agreement in certain respects as therein set forth; and

       WHEREAS, Borrower and Lender entered into a Third Amendment to Loan
  Agreement, dated as of December 22, 1994 (the "Third Amendment") amending the
  Loan Agreement in certain respects as therein set forth; and 

       WHEREAS, Borrower has requested that the Lender extend the maturity,
  increase the amount of the term loan and make certain other changes to the
  Loan Agreement and the Bank is willing to extend, increase and amend such
  commitment.

       NOW, THEREFORE, the parties hereby agree to amend the Loan Agreement as
  follows:

       1.   Unless otherwise defined herein, all defined terms used herein
  shall have the same meaning ascribed to such terms in the Loan Agreement, as
  amended by the First, Second and Third Amendments.

       2.   The definition of "Commitment" in Section 1.01 is hereby amended by
  deleting the same in its entirety and inserting the following in lieu
  thereof:  
                 ""Commitment" means $16,062,500.00."

       3.   The definition of "Oil and Gas Properties" in Section 1.01 is
  hereby amended by deleting the same in its entirety and inserting the
  following in lieu thereof:

                 ""Oil and Gas Properties" means the properties set forth
            on Exhibit AA together with any and all additional oil, gas
            and mineral properties and interests in which Borrower has
            granted and hereinafter grants to Bank first perfected Liens."

       4.   The definition of "Principal Payment Date" in Section 1.01 is
  hereby amended by deleting the reference therein to "January 1, 1995" and
  inserting in lieu thereof "April 1, 1995".

       5.   The definition of "Term Maturity Date" in Section 1.01 is hereby
  amended by deleting the same in its entirety and inserting the following in
  lieu thereof: 

                 ""Term Maturity Date" means April 1, 2000."

       6.   The definition of "Total Liabilities" in Section 1.01 is hereby
  amended by deleting the same in its entirety and inserting the following in
  lieu thereof:

                 ""Total Liabilities" means Funded Debt, plus Current
            Liabilities, minus Permitted Purchase Money Indebtedness,
            minus Non Recourse Debt minus deferred Taxes plus all other
            liabilities which would be reflected in a balance sheet
            prepared in accordance with GAAP, of Borrower."

       7.   Section 3.04(a) of the Loan Agreement is hereby deleted in its
  entirety and the following inserted in lieu thereof:

                 "(a)  Note.  The unpaid principal balance of the Note
            shall be due and payable in consecutive monthly installments,
            with one such installment in the amount of $437,500 plus
            accrued but unpaid interest due on April 1, 1995, followed by
            consecutive installments of $781,250 plus accrued but unpaid
            interest, payable on each Principal Payment Date thereafter,
            beginning July 1, 1995 and continuing regularly thereafter,
            with a final installment due and payable on the Term Maturity
            Date in an amount equal to the outstanding principal balance
            plus all accrued but unpaid interest."

       8.   Section 8.01 of the Loan Agreement is hereby deleted in its
  entirety and the following inserted in lieu thereof:

                 "8.01  Debt to Worth Ratio.  Borrower will not
            suffer or permit the ratio of (i) the aggregate of Total
            Liabilities to (ii) Net Worth at any time to be greater
            than 0.7 to 1.0."

       9.   The $16,062,500.00 Renewal Term Note (the "Note") attached hereto
  as Exhibit "A" shall replace the $7,000,000.00 Term Note attached to the
  Third Amendment to Loan Agreement as Exhibit "A".

       10.  This Fourth Amendment shall be effective as of the date first above
  written (the "Effective Date").

       11.  The obligation of the Bank under this Fourth Amendment and its
  obligation to increase and extend the Loan shall be subject to the following
  conditions precedent:  

            (a)  Execution and Delivery.  Borrower shall have executed and
       delivered to the Bank this Fourth Amendment, the Note, the Security
       Documents, and other required documents, all in form and substance
       satisfactory to the Bank;

            (b)  Legal Opinion.  Bank shall have received from Borrower's legal
       counsel a favorable legal opinion in form and substance satisfactory to
       Bank, generally in the form of the opinion furnished in connection with
       the execution of the Loan Agreement on October 1, 1990;

            (c)  Corporate Resolutions.  Bank shall have received appropriate
       certified corporate resolutions for the Borrower;

            (d)  Incumbency.  The Bank shall have received a signed certificate
       of the officers of Borrower, certifying the names of each of the
       officers of Borrower authorized to sign loan documents on behalf of the
       Borrower, together with the true signatures of each such officer.  The
       Bank may conclusively rely on such certificate until the Bank receives a
       further certificate of the authorized officers of Borrower canceling or
       amending the prior certificate and submitting signatures of the officers
       named in such further certificate; 

            (e)  Good Standing.  The Bank shall have received evidence of good
       standing of the Borrower issued by the Secretary of State of the State
       of Delaware;

            (f)  Articles of Incorporation and Bylaws.  The Bank shall have
       received copies of the Articles of Incorporation of Borrower and all
       amendments thereto, certified by the Secretary of State of the State of
       Delaware and a copy of the bylaws of the Borrower and all amendments
       thereto, certified by one or more officers of Borrower as being true,
       correct and complete;

            (g)  Title.  The Bank shall have received satisfactory evidence as
       to the state of the title of the Oil and Gas Properties being mortgaged
       to the Bank on the Effective Date;

            (h)  Other Documents.  The Bank shall have received such other
       instruments and documents incidental and appropriate to the transaction
       provided for herein as the Bank or its counsel may reasonably request,
       and all such documents shall be in form and substance satisfactory to
       the Bank; and

            (i)  Legal Matters Satisfactory.  All legal matters incident to the
       consummation of the transactions contemplated hereby shall be
       satisfactory to special counsel for the Bank retained at the expense of
       Borrower.

       12.  Except to the extent its provisions are specifically amended,
  modified or superseded by this Fourth Amendment, the representations,
  warranties and affirmative and negative covenants of the Borrower contained
  in the Loan Agreement are incorporated herein by reference for all purposes
  as if copied herein in full.  The Borrower hereby restates and reaffirms each
  and every term and provision of the Loan Agreement, including, without
  limitation, all representations, warranties and affirmative and negative
  covenants.  

       All factual information heretofore and contemporaneously furnished by or
  on behalf of Borrower to Lender for purposes of or in connection with this
  Fourth Amendment does not contain any untrue statement of a material fact or
  admit to state any material fact necessary to keep the statements contained
  herein or therein from being misleading.  Each of the foregoing
  representations and warranties shall constitute a representation and warranty
  of Borrower made under the Loan Agreement, and it shall be an Event of
  Default if any such representation and warranty shall prove to have been
  incorrect or false in any material respect at the time given.  Each of the
  representations and warranties made under the Loan Agreement (including those
  made herein) shall survive and not be waived by the execution and delivery of
  this Fourth Amendment or any investigation by Lender.

       13.  Except to the extent its provisions are specifically amended,
  modified or superseded by this Fourth Amendment, the Loan Agreement, as
  amended by the First and Second and Third Amendment, and all terms and
  provisions thereof shall remain in full force and effect, and the same in all
  respects are confirmed and approved by the Borrower and Bank.

       14.  The Borrower agrees to indemnify and hold harmless the Bank and its
  officers, employees, agents, attorneys and representatives (singularly, an
  "Indemnified Party", and collectively, the "Indemnified Parties") from and
  against any loss, cost, liability, damage or expense (including the
  reasonable fees and out-of-pocket expenses of counsel to an Indemnified
  Party, including all local counsel hired by such counsel), relating to any
  claim by a party other than the Borrower arising from or brought against any
  Indemnified Party (i) as a result of or based on any action or omission of
  the Borrower or its officers, directors, employees or agents and (ii) in
  connection with or in any manner related to the Loan Agreement, as amended,
  or any other loan document, the performance or breach of or the making of any
  Advance or borrowing under the commitment in the Loan Agreement, the issuance
  of any letter of credit or the use of the proceeds of any drawing thereunder,
  the maintenance of any loan under the Loan Agreement, the consummation of the
  transactions contemplated in the Loan Agreement, as amended, or in connection
  herewith, the use of any of the proceeds of any loan under the Loan
  Agreement, any claimed obligation or responsibility of any Indemnified Party
  for the management, operation or conduct of the business or affairs of the
  Borrower or the payment of any debt of the Borrower or any act or omission by
  the Borrower, whether actual or alleged unless the action taken by the
  Borrower is specifically demanded or required in writing by an Indemnified
  Party after the Borrower has advised the Bank in writing of its opposition to
  such action.  In addition to the foregoing, the Borrower shall defend,
  indemnify, and hold harmless each Indemnified Party from any and all
  liabilities (including strict liability), actions, demands, penalties,
  losses, costs, expenses (including, without limitation, reasonable attorneys'
  fees and expenses and investigatory and remedial costs), suits, costs, any
  settlement or judgment, and claims of any and every kind whatsoever which may
  now or in the future be paid, incurred, or suffered by or asserted against
  any Indemnified Party by any person or entity (other than the Borrower) or
  governmental agency for, with respect to, or as a result or direct result of
  any environmental liability which arises out of or result from the
  environmental condition of any property owned by the Borrower or the
  applicability of any environmental law or any rule, regulation, order or
  decree related to any environmental law, regardless of whether caused by or
  within the control of the Borrower or any Indemnified Party unless the action
  taken by the Borrower is specifically demanded or required in writing by an
  Indemnified Party after the Borrower has advised the Bank in writing of its
  opposition to such action.  The indemnity set forth herein shall be in
  addition to any other obligations or liabilities of Borrower to the Bank
  hereunder or at common law or otherwise, and shall survive any termination of
  this Fourth Amendment, the expiration of the Revolving Loan Commitment and
  the payment of all indebtedness of Borrower to any Indemnified Party
  hereunder and under the Note, provided that Borrower shall have no obligation
  under this paragraph to any Indemnified Party with respect to any of the
  foregoing arising out of gross negligence or willful misconduct of such
  Indemnified Party.  THE PARTIES INTEND FOR THE PROVISIONS OF THIS PARAGRAPH
  TO APPLY TO AND PROTECT EACH INDEMNIFIED PARTY FROM THE CONSEQUENCES OF ITS
  OWN NEGLIGENCE, WHETHER OR NOT THAT NEGLIGENCE IS THE SOLE, CONTRIBUTING OR
  CONCURRING CAUSE OF ANY SUCH LOSS, COSTS, LIABILITY, DAMAGE OR EXPENSE
  INDEMNIFIED AGAINST IN THIS PARAGRAPH. 

       15.  WRITTEN LOAN AGREEMENT.  THE LOAN AGREEMENT, AS AMENDED BY THE
  FIRST AMENDMENT, THE SECOND AMENDMENT, THE THIRD AMENDMENT AND THIS FOURTH
  AMENDMENT, REPRESENTS THE FINAL AGREEMENT BETWEEN AND AMONG THE PARTIES AND
  MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT
  ORAL AGREEMENTS OF THE PARTIES.  THERE ARE NO UNWRITTEN ORAL AGREEMENTS
  BETWEEN AND AMONG THE PARTIES.

       IN WITNESS WHEREOF, the parties have caused this Fourth Amendment to
  Loan Agreement to be duly executed as of the date first above written.

                                BORROWER:

                                MAYNARD OIL COMPANY
                                a Delaware corporation 


                                By: ------------------------------------
                                     Glenn R. Moore, President


                                LENDER:

                                BANK ONE, TEXAS, N.A.,
                                a national banking association


                                By: ------------------------------------
                                     Michael W. Mitchell
                                     First Vice President



                                                                     EXHIBIT A

                                RENEWAL TERM NOTE 


  $16,062,500.00                   Dallas, Texas                March 29, 1995


       FOR VALUE RECEIVED, the undersigned, MAYNARD OIL COMPANY, a Delaware
  corporation (the "Borrower") hereby promises to pay to the order of BANK ONE,
  TEXAS, N.A., a national banking association ("Payee"), at the offices of
  Payee, 1717 Main Street, Dallas, Texas 75201, or at such other place as the
  holder hereof may direct, in lawful money of the United States of America,
  the principal amount of SIXTEEN MILLION SIXTY-TWO THOUSAND FIVE HUNDRED and
  00/100 DOLLARS ($16,062,500.00), together with interest thereon from the date
  hereof on the unpaid principal amount hereof from time to time outstanding at
  the rates stated in that certain Loan Agreement, dated October 1, 1990, as
  amended, entered into among Borrower and Payee (as the same may be amended,
  modified, increased, supplemented and/or restated from time to time, the
  "Agreement").  All terms defined in the Agreement shall have the same meaning
  when used herein.  

       16.  Payment Terms.  The principal of, and all accrued interest upon,
  this Note shall be due and payable in consecutive monthly installments, with
  one such installment in the amount of $437,500.00 plus accrued and unpaid
  interest payable on April 1, 1995, followed by consecutive installments of
  $781,250.00 plus accrued but unpaid interest, payable on each Principal
  Payment Date thereafter, beginning July 1, 1995, and continuing regularly
  thereafter, with a final installment due and payable on April 1, 2000 in an
  amount equal to the outstanding principal balance plus all accrued but unpaid
  interest.

       17.  Prepayment.  Borrower shall be entitled and in certain instances
  may be required to prepay the principal of this Note from time to time in
  accordance with the Agreement. 

       18.  Benefits.  This Note is a renewal, extension and increase of the
  Term Note, in the amount of $7,000,000.00, executed by Borrower and payable
  to the order of Payee, dated December 22, 1994, which Note renewed, extended
  and increased a Term Note in the amount of $10,000,000.00 executed by
  Borrower and First City, Texas-Dallas, N.A., dated October 1, 1990, which
  Note was assigned to the Payee on February 1, 1993, and the holder hereof is
  entitled to the benefits thereof and may enforce the agreements contained
  therein and exercise the rights provided for thereby or otherwise in respect
  thereof.  Reference to the Agreement shall not affect or impair the absolute
  unconditional obligation of Borrower to pay the principal of, interest on and
  any additional payment in connection with this Note when due. 

       19.  Security.  The payment of this Note is secured by liens and
  security interests more particularly described in the Agreement. 

       20.  Acceleration of Maturity.  Upon the occurrence of an Event of
  Default under the Agreement, the holder of this Note, at its option, may (i)
  declare the principal of, and all interest then accrued on, this Note, to be
  forthwith due and payable, whereupon the same shall forthwith become due and
  payable without presentment, demand, protest, or notice of any kind, all of
  which Borrower hereby expressly waives, and/or (ii) exercise of any other
  right provided in the Loan Documents, or at law or in equity.  Reference is
  hereby made to the Agreement for a statement of the events upon which the
  maturity of this Note may be accelerated automatically.  Borrower grants to
  holder the right to set off against this Note, and the right of recoupment
  from, any and all deposit and other liabilities of holder to Borrower and all
  money or property in the possession of any holder held for or owed to
  Borrower. 

       21.  Waiver.  Except as otherwise expressly provided herein or in the
  other Loan Documents, Borrower and all sureties, endorsers and guarantors of
  this Note (i) waive demand, presentment for payment, notice of intention to
  accelerate, notice of acceleration, protest, notice of protest, notice of
  default and all other notices, filing of suit and diligence in collecting
  this Note or enforcing any of the security herefor, (ii) agree to any
  substitution, exchange or release of any such security or the release of any
  person or entity primarily or secondarily liable herefor, (iii) agree that it
  will not be necessary for any holder hereof, in order to enforce payment of
  this Note by such holder, to first institute suit or exhaust its rights
  against Borrower or others liable herefor, or to enforce its rights against
  any security herefor, and (iv) consent to any and all extensions for any
  period, renewals or postponements of time of payment of this Note or any
  other indulgences with respect hereto, without notice thereof to any of them.

       22.  Attorneys' Fees.  If this Note is collected by legal proceedings or
  in or through a bankruptcy court, or is placed in the hands of an attorney
  for collection after maturity, no matter how maturity is brought about,
  Borrower agrees to pay reasonable attorneys fees and all other collection
  costs incurred by the holder of this Note. 

       23.  GOVERNING LAW AND VENUE.  THIS NOTE SHALL BE CONSTRUED IN
  ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF TEXAS AND APPLICABLE
  FEDERAL LAW AND SHALL BE PERFORMABLE IN DALLAS COUNTY, TEXAS, OR AT SUCH
  OTHER PLACE AS MAY BE DESIGNATED IN WRITING BY THE HOLDER HEREOF. 

       24.  Headings.  The headings of the sections of this Note are inserted
  for convenience only and shall not be deemed to constitute a part hereof. 

       25.  Renewal.  This Renewal Term Note is given in renewal, increase and
  extension of, and not in extinguishment of, that certain Term Note, in the
  amount of $7,000,000.00, executed by Borrower and payable to the order of
  Payee, dated December 22, 1994, which Note renewed and extended, but did not
  extinguish that certain Term Note, dated October 1, 1990, executed by
  Borrower payable to the order of First City, Texas-Dallas, N.A., Term Note
  was assigned to Payee on February 1, 1993.

       IN WITNESS WHEREOF, Borrower has executed this Note as of the date and
  year first herein written. 

                                BORROWER:

                                MAYNARD OIL COMPANY



                                By: -------------------------------------
                                     Glenn R. Moore, President