EXHIBIT 10.1.20 LOAN AGREEMENT Dated as of August 3, 1995 between UNIT CORPORATION UNIT DRILLING AND EXPLORATION COMPANY MOUNTAIN FRONT PIPELINE COMPANY, INC. UNIT DRILLING COMPANY UNIT PETROLEUM COMPANY PETROLEUM SUPPLY COMPANY ROUNDUP RESOURCES, INC. "Borrowers" and BANK OF OKLAHOMA, NATIONAL ASSOCIATION THE FIRST NATIONAL BANK OF BOSTON BANK IV OKLAHOMA, N.A. AMERICAN NATIONAL BANK AND TRUST COMPANY OF SHAWNEE "Banks" and BANK OF OKLAHOMA, NATIONAL ASSOCIATION "Agent" LOAN AGREEMENT THIS LOAN AGREEMENT, dated as of August 3, 1995 ("Agree- ment"), is entered into among UNIT CORPORATION, a Delaware corpora- tion ("Unit"), UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation, MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation, UNIT DRILLING COMPANY, an Oklahoma corporation, UNIT PETROLEUM COMPANY, an Oklahoma corporation, PETROLEUM SUPPLY COMPANY, an Oklahoma corporation, and ROUNDUP RESOURCES, INC., a Delaware corporation, each with its principal place of business at 1000 Galleria Tower 1, 7130 South Lewis, Tulsa, Oklahoma 74136 (collectively the "Borrowers") and BANK OF OKLAHOMA, NATIONAL ASSOCIATION, a national banking association, with principal offices at Bank of Oklahoma Tower, 7 East 2nd Street, Tulsa, Oklahoma 74172 ("BOK"); THE FIRST NATIONAL BANK OF BOSTON, a national banking association, with principal offices at 100 Federal Street, Boston, Massachusetts 02110 ("Bank of Boston"); BANK IV OKLAHOMA, N.A., a national banking association, formerly known as The Fourth National Bank of Tulsa, with principal offices at 515 South Boulder, Tulsa, Oklahoma, 74119 ("BANK IV"); and AMERICAN NATIONAL BANK AND TRUST COMPANY OF SHAWNEE, a national banking association, with principal offices at 201 N. Broadway, Shawnee, Oklahoma 74801 ("ANB") (BOK, Bank of Boston, BANK IV and ANB each being sometimes referred to herein, individually, as a "Bank", and collectively as the "Banks"); and BOK as Agent for the Banks (in such capacity, herein referred to as the "Agent"). WITNESSETH: WHEREAS, the Borrowers have applied to the Banks for a certain revolving line of credit (the "Line Commitment") in the maximum principal amount of SEVENTY FIVE MILLION AND NO/100 DOLLARS ($75,000,000) to be evidenced by Borrowers' joint and several promissory notes dated as of even date herewith for the purposes of (i) paying off the aggregate unpaid balance of the existing loan owing by the Borrowers to BOK, BANK IV and ANB, (ii) funding future oil and gas property acquisitions and development drilling expenses (iii) the issuance of standby letters of credit from time to time in accordance with and subject to the terms, provisions and conditions hereof, (iv) funding general working capital require- ments and (iv) funding drilling equipment expenditures; WHEREAS, pursuant to the terms and provisions hereof, the unpaid principal balance of the Line Commitment will be converted to a forty-eight (48) month term payment (the "Term Commitment") (the Line Commitment and the Term Commitment are sometimes collectively referred to herein as the "Commitments"); and WHEREAS, the Banks are willing to extend the Commitments to the Borrowers upon the terms and conditions herein set forth, all of which are material to the Banks and without which the Banks would not be willing to extend any of the loan commitments described above. NOW, THEREFORE, in consideration of the mutual covenants and agreements contained herein, and other good and valuable consid- eration, receipt of which is acknowledged by the parties hereto, the parties agree, as follows: ARTICLE I CERTAIN DEFINITIONS When used herein, the following terms shall have the follow- ing meanings: 1.1 "Applicable Prime Rate" shall mean the annual rate of interest announced by Chase Manhattan Bank (National Association) New York, New York ("Chase") from time to time as its prime or base rate, which shall be the rate used by Chase as a base or standard for pricing purposes and which shall not necessarily be its "best" or lowest rate. Should Chase cease to announce a prime or base rate, or should it be merged, consolidated, liquidated or dissolved in such a manner that it loses its separate corporate or banking identity, then the Applicable Prime Rate shall be the Prime Rate published by the Wall Street Journal in its "Money Rates" column, or a similar rate if such rate ceases to be published. Any change in the Applicable Prime Rate shall be effective as of the date of the change. 1.2 "Business Day" shall mean a day other than a Saturday, Sunday or a day upon which banks in the State of Oklahoma are closed to business generally. 1.3 "CERCLA" shall mean the Comprehensive Environmental Response, Compensation and Liability Act of 1980, as amended, together with all regulations and rulings promulgated with respect thereto. 1.4 "Closing Date" shall mean the effective date of this Agreement. 1.5 "Collateral" shall mean the Current Collateral and the Additional Collateral, as defined herein in Article IV. 1.6 "Commitment Termination Date" shall mean August 31, 1997 unless the Commitment is terminated at an earlier date pursuant to the terms of this Agreement. 1.7 "Commitments" shall mean the Line Commitment and the Term Commitment. 1.8 "Consolidated Tangible Net Worth" shall mean the sum of (a) the par value of Unit's consolidated capital stock (excluding treasury stock), (b) Unit's consolidated paid-in capital, and (c) the amount of Unit's consolidated retained earnings minus any 2 consolidated intangible assets such as organization costs or goodwill, all as reflected in the financial statements furnished to the Banks under this Agreement. 1.9 "Corresponding Source of Funds" shall mean in the case of any Libor Rate Funding Segment of the Libor Rate Portion, the proceeds of hypothetical receipts by the Agent through a branch, subsidiary or affiliate of one or more Dollar deposits in the interbank eurodollar market at the beginning of the Libor Rate Funding Period corresponding to such Libor Rate Funding Segment, having maturities approximately equal to such Libor Rate Funding Period and in an aggregate amount approximately equal to such Libor Rate Funding Segment. 1.10 "Current Assets" shall mean the total amount of Unit's current assets determined in accordance with GAAP on a consolidated basis. 1.11 "Current Liabilities" shall mean the total amount of Unit's current liabilities determined in accordance with GAAP on a consolidated basis, excluding, however (i) current maturities of indebtedness of the Borrowers to the Banks as provided in this Agreement, and (ii) liabilities associated with gas purchase prepayments. 1.12 "Current Maturities of Long Term Debt" shall mean obligations under Long Term Debt due within one year or less, as reflected on Unit's financial statements furnished to the Banks pursuant to this Agreement. 1.13 "Current Ratio" shall mean the ratio of Current Assets to Current Liabilities. 1.14 "Default Rate" shall mean the Applicable Prime Rate plus five percentage points (5.0%) per annum. 1.15 "Dollar", "Dollars" and the symbol "$" shall mean lawful money of the United States of America. 1.16 "Environmental Laws" shall mean Laws, including without limitation federal, state or local Laws, ordinances, rules, regulations, interpretations and orders of courts or administrative agencies or authorities relating to pollution or protection of the environment (including, without limitation, ambient air, surface water, groundwater, land surface and subsurface strata), including without limitation CERCLA, SARA, RCRA, HSWA, OPA, HMTA, TSCA and other Laws relating to (i) Polluting Substances or (ii) the manufacture, processing, distribution, use, treatment, handling, storage, disposal or transportation of Polluting Substances. 1.17 "ERISA" shall mean the Federal Employee Retirement Income Security Act of 1974, as amended, together with all regu- lations and rulings promulgated with respect thereto. 3 1.18 "Event of Default" shall mean any of the events speci- fied in Section 8.1 of this Agreement, and "Default" shall mean any event, which together with any lapse of time or giving of any notice, or both, would constitute an Event of Default. 1.19 "GAAP" shall mean generally accepted accounting princi- ples applied on a consistent basis in all material respects to those applied in the preceding period. Unless otherwise indicated herein, all accounting terms will be defined according to GAAP. 1.20 "hereby", "herein", "hereof", "hereunder" and similar such terms shall mean and refer to this Agreement as a whole and not merely to the specific section, paragraph or clause in which the respective word appears. 1.21 "HMTA" shall mean the Hazardous Materials Transportation Act, as amended, together with all regulations and rulings promulgated with respect thereto. 1.22 "HSWA" shall mean the Hazardous and Solid Waste Amend- ments of 1984, as amended, together with all regulations and rulings promulgated with respect thereto. 1.23 "Indebtedness" shall mean and include any and all: (i) indebtedness, obligations and liabilities of the Borrowers to the Banks and the Agent incurred or which may be incurred hereafter pursuant to the terms of this Agreement or any of the other Loan Documents, and any extensions, renewals, substitutions, amendments and increases in amount thereof, including such amounts as may be evidenced by the Notes and all lawful interest, letters of credit fees, service fees, commitment fees and other charges, and all reasonable costs and expenses incurred in connection with the preparation, filing and recording of the Loan Documents, including attorneys fees; (ii) all reasonable costs and expenses, including attorneys' fees, paid or incurred by the Banks or the Agent in enforcing or attempting to enforce collection of any Indebtedness and in enforcing or realizing upon or attempting to enforce or realize upon any collateral or security for any Indebtedness and in protecting and preserving the Banks' interest in the Indebtedness or any collateral or security for any Indebtedness in any bank- ruptcy or reorganization proceeding, including interest on all sums so expended by the Banks or the Agent accruing from the date upon which such expenditures are made until paid, at an annual rate equal to the Default Rate; (iii) sums expended by the Banks in curing any Event of Default or Default of the Borrowers under the terms of the Loan Documents or any other security agreement or other writing evidencing or securing the payment of the Notes together with interest on all sums so expended by the Banks or the Agent accruing from the date upon which such expenditures are made until paid, at an annual rate equal to the Default Rate; and (iv) all "Indebtedness" or "Secured Indebtedness" as said terms are defined in each of the Loan Documents. 4 1.24 "Intercreditor Agreement" shall mean the Intercreditor Agreement dated of even date herewith among BOK, BANK IV, Bank of Boston, ANB and the Agent. 1.25 "Laws" shall mean all statutes, laws, ordinances, regulations, orders, writs, injunctions, or decrees of the United States, any state or commonwealth, any municipality, any foreign country, any territory or possession, or any Tribunal. 1.26 "Letters of Credit" shall mean any and all letters of credit issued by BOK pursuant to the request of any of the Borrowers in accordance with the provisions hereof which at any time remain outstanding and subject to draw by the beneficiary, whether in whole or in part. 1.27 "Libor Rate" shall mean for any day the rate per annum of interest (rounded upwards, if necessary, to the nearest 1/16 of 1%) (which shall be the same for each day in the Libor Rate Funding Period selected) determined pursuant to the following formula: Rate Libor Rate = 1.00 - Libor Reserve Percentage The Libor Rate for any Libor Rate Funding Period for the Libor Rate Option will be determined by the Agent on the basis of the Libor Reserve Percentage in effect two (2) London Business Days prior to the first day of a Libor Rate Funding Period and the applicable Rate as described below. "Rate" means for any day the rate per annum of interest (rounded upwards, if necessary, to the nearest 1/16 of 1%) quoted for the "London Interbank Offered Rates (LIBOR)" by Agent's Capital Markets Division for the selected Libor Rate Funding Period available hereunder for the Libor Rate Option two (2) London Business Days prior to the first day of such Libor Rate Funding Period. "Libor Reserve Percentage" means, relative to any Libor Rate Funding Period available hereunder for the Libor Rate Option, the reserve percentage (expressed as a decimal) equal to the maximum aggregate reserve requirements (including all basic, emergency, supplemental, marginal and other reserves and taking into account any transitional adjustments or other scheduled changes in reserve requirements) specified under regulations issued from time to time by the Federal Reserve System Board and then applicable to assets or liabilities consisting of and including "Eurocurrency Liabilities", as currently defined in Regulation D of the Federal Reserve System Board, having a term approximately equal or comparable to such Libor Rate Funding Period. The Agent shall give prompt notice to the Borrowers of the Libor Rate so determined or adjusted, which determination or adjustment shall be conclusive if made in good faith absent manifest or demonstrable error. 1.28 "Libor Rate Funding Period" shall have the meaning assigned to that term or described in Section 2.5(b) hereof. 5 1.29 "Libor Rate Funding Segment" shall mean that portion of the outstanding principal amount of the Notes to which a Libor Rate Option applies for the applicable Libor Rate Funding Period begin- ning on a particular day and ending on another particular day. 1.30 "Libor Rate Option" shall have the meaning assigned to that term in Section 2.5(a) hereof. 1.31 "Lien" shall mean any mortgage, pledge, security interest, encumbrance, lien or charge of any kind (including any agreement to give any of the foregoing, any conditional sale or other title retention agreement, any lease in the nature thereof, and the filing of or agreement to give any financing statement or other similar form of public notice under the Laws of any juris- diction). 1.32 "Lien Notice" shall mean notice received or obtained by the Agent or the Banks or knowledge obtained by the Agent or the Banks of any Lien being claimed (whether valid or not) by any Person, other than the Agent or the Banks or a trustee on behalf of the Agent or the Banks, with respect to the Borrowers' assets and properties. 1.33 "Line Loan" shall have the meaning ascribed to it in Section 2.1 of this Agreement. 1.34 "Loan Documents" shall mean this Agreement, the Notes, the Security Instruments and all other documents, instruments and certificates executed and delivered to the Banks and the Agent by the Borrowers pursuant to the terms of this Agreement. 1.35 "Loan Value" shall have the meaning assigned to that term or described in Section 3.1(b) hereof. 1.36 "London Business Day" shall mean a day for dealing in deposits in Dollars by and among banks in the London interbank mar- ket which is also a Business Day. 1.37 "Long Term Debt" shall mean all obligations of Unit and its consolidated subsidiaries reflected on the consolidated financial statements furnished to the Banks that are due in more than one year, excluding, however, liabilities associated with gas purchase prepayments. 1.38 "Majority Banks" shall mean the Agent and either one or both of Bank of Boston or BANK IV. 1.39 "Mineral Interests" shall mean all of the Borrowers' mineral and leasehold interests. 1.40 "Notes" shall have the meaning ascribed to it in Section 2.2 of this Agreement together with each and every extension, renewal, modification, replacement, substitution and change in form 6 thereof which may be from time to time and for any term or terms effected. 1.41 "OPA" shall mean the Oil Pollution Act of 1990, as amended, together with all regulations and rulings promulgated with respect thereto. 1.42 "Official Body" shall mean any government or political subdivision or any agency, authority, bureau, central bank, commission, department or instrumentality of either, or any court, tribunal, grand jury or arbitrator, in each case whether foreign or domestic. 1.43 "Options" shall mean the Prime Rate Option and the Libor Rate Option, as the case may be. 1.44 "Person" shall mean and include an individual, a partnership, a joint venture, a corporation, a trust, an unincor- porated organization, and a government or any department, agency or political subdivision thereof. 1.45 "Polluting Substances" shall mean all pollutants, contaminants, chemicals or industrial, toxic or hazardous sub- stances or wastes and shall include, without limitation, any flammable explosives, radioactive materials, oil, hazardous materials, hazardous or solid wastes, hazardous or toxic substances or related materials defined in CERCLA/SARA, RCRA/HSWA and in the HMTA; provided, in the event either CERCLA/SARA, RCRA/HSWA or HMTA is amended so as to broaden the meaning of any term defined thereby, such broader meaning shall apply subsequent to the effective date of such amendment and, provided further, to the extent that the Laws of any State or other Tribunal establish a meaning for "hazardous substance," "hazardous waste," "hazardous RCRA/HSWA material," "solid waste" or "toxic substance" which is broader than that specified in CERCLA/SARA or HMTA, such broader meaning shall apply. 1.46 "Prime Rate Option" shall have the meaning assigned to that term in Section 2.5(a) hereof. 1.47 "Pro Rata Share" shall mean for each of the Banks the percentage determined from time to time by dividing the principal amount outstanding under such Bank's respective Note by the aggregate principal amount outstanding under all of the Banks' Notes. Initially, BOK's Pro Rata Share is 47%, BANK IV's Pro Rata Share is 40%, Bank of Boston's Pro Rata Share is 10% and ANB's Pro Rata Share is 3%. 1.48 "RCRA" shall mean the Resource Conservation and Recovery Act of 1976, as amended, together with all regulations and rulings promulgated with respect thereto. 7 1.49 "Redetermination Date" shall mean May 1 and November 1 of each year. 1.50 "SARA" shall mean the Superfund Amendments and Re- authorization Act of 1987, as amended, together with all regu- lations and rulings promulgated with respect thereto. 1.51 "Security Agreement" shall have the meaning assigned to that term in Article IV of this Agreement. 1.52 "Security Instruments" shall mean the Security Agreement and all other financing statements, mortgages, assignments, security agreements, documents or writings of any and all amend- ments and supplements thereto, granting, conveying, assigning, transferring or in any manner providing the Agent with a security interest or mortgage lien in any property as security for the repayment of all or any part of the Indebtedness. 1.53 "Taxes" shall mean all taxes, assessments, fees, or other charges or levies from time to time or at any time imposed by any Laws or by any Tribunal. 1.54 "Term Loan" shall have the meaning ascribed to it in Section 2.4(a) of this Agreement. 1.55 "Total Liabilities" shall mean the total amount of all liabilities of Unit, as reflected on the consolidated financial statements, including capitalized leases and excluding liabilities associated with gas purchase prepayments. 1.56 "Tribunal" shall mean any municipal, state, common- wealth, Federal, foreign, territorial or other sovereign, govern- mental entity, governmental department, court, commission, board, bureau, agency or instrumentality. 1.57 "TSCA" shall mean the Toxic Substances Control Act, as amended, together with all regulations and rulings promulgated with respect thereto. 1.58 "Working Capital Provided from Operations" shall mean Unit's consolidated net income plus (minus) Unit's consolidated depreciation, noncurrent deferred income taxes, and other nonwork- ing capital charges (credits), as such items are reflected in the financial statements furnished to the Banks pursuant to this Agreement. ARTICLE II LOANS 2.1 Revolving Line of Credit. Each of the Banks agrees, severally and not jointly, upon the terms and subject to the 8 conditions hereinafter set forth, to establish a combined revolving line of credit and make loans (the "Line Loan") to the Borrowers administered by the Agent from the Closing Date until August 31, 1997 (the "Commitment Termination Date"), in such amounts as the Borrowers may from time to time request and BOK will issue letters of credit on Borrowers' account so long as the aggregate unpaid principal amount of the Line Loan advanced, outstanding and unpaid at any time under the Notes as cash advances thereon (including the unfunded portions of outstanding Letters of Credit issued pursuant to Section 2.3(b) hereof) does not exceed the lesser of (a) $75,000,000 (or such lesser amount as may be established from time to time pursuant to Section 2.7 hereof) (the "Commitment Amount") or (b) the Borrowing Base (as determined in accordance with Section 3.1 hereof). In no event shall any of the Banks be obligated to make advances under this Agreement in excess of the stated princi- pal amount of each Bank's respective Note. 2.2 Notes. The Borrowers' obligation to repay the Line Loan made by the Banks, together with interest accruing thereon, shall be evidenced by Borrowers' four (4) joint and several promissory notes of even date herewith, in the form of Exhibits A-1, A-2, A-3 and A-4 attached hereto (which promissory notes, together with all extensions, renewals, substitutions, replacements, rearrangements and changes in form thereof are each sometimes hereinafter referred to, individually, as a "Note", and, collectively, as the "Notes"). 2.3 Advances; Letters of Credit. (a) Advances. Subject to the terms, conditions and limitations set forth in this Agreement, each Bank severally, and not jointly, agrees to advance its Pro Rata Share of each advance. Except for advances to reimburse BOK for drafts paid under Letters of Credit, the Banks shall not be obligated to make any advance which is (i) in an amount less than $100,000 or, if greater than $100,000, in an amount not an integral multiple of $50,000, (ii) requested on or after the Commit- ment Termination Date, or (iii) requested to be made while any Event of Default is in existence, or when the making of such advance would cause an Event of Default to occur. Within such limitations and the limitations set forth in this Agreement, Borrowers may borrow, repay and reborrow under the Line Loan until the Commitment Termination Date. Borrowers shall give Agent notice by telephone at or before 12:00 o'clock noon (Tulsa time) on the proposed date of any advance. Each such advance shall be made at the office of the Agent by crediting the amount of the advance to Unit's demand deposit account with the Agent styled as follows: Unit Corporation Account No. 209907163 (the "General Account"). In consideration of Banks and the Agent permitting Borrowers to make requests for advances by 9 telephone, Borrowers jointly state that they are fully aware of the risks attendant thereto, and agree to accept all such risks and to hold Banks and the Agent harmless from any loss which any Borrowers may incur by reason of any such nonwritten request, other than such as result from a Bank's or the Agent's gross negligence or wanton disregard. (b) Letters of Credit. Upon the Borrowers' application from time to time by use of BOK's standard form Letter of Credit Application Agreement and subject to the terms and provisions therein and herein set forth, BOK agrees to issue standby letters of credit on behalf of the Borrowers under the Line Commitment, provided that (i) any letters of credit issued on behalf of or on the account of Borrowers with an expiry date later than the Commitment Termination Date, will, at the Banks' sole option, be fully secured and collateral- ized by cash or cash equivalent acceptable to the Banks in their sole discretion and held thereby from and after maturity, until expiration or cancellation of such letter(s) of credit or payment of all draws thereon on demand of the Banks, (ii) no letter of credit will be issued on behalf of or for the account of the Borrowers if at the time of issuance the outstanding amount of the unpaid Line Loan (including the aggregate outstanding and unfunded amount of unexpired letters of credit then existing) under the Line Commitment as evidenced by the Notes plus the maximum amount of such Letter of Credit then being requested would exceed the Borrowing Base, and (iii) in no event shall the aggregate amount of such outstanding letters of credit exceed $10,000,000. If any letter of credit is drawn upon at any time, each amount drawn, whether a full or partial draw thereon, shall be paid by wire transfer and reflected by the Banks as an advance on the Notes, based on the Banks' Pro Rata Share, effective as of the date the sight draft is honored and such letter of credit shall be cancelled immedi- ately, or partially reduced, as may be appropriate, upon such wire transfer. In consideration of BOK's agreement to issue letters of credit hereunder, the Borrowers agree to pay to the Agent letter of credit fees equal to one and one-half percent (1 1/2%) per annum on the face amount of each letter of credit plus normal processing fees, which such fees shall be paid to the Agent at the time of issuance of each applica- ble letter of credit by an automatic debit in such amount to the General Account (the "Letter of Credit Fees"). All letters of credit issued by BOK pursuant to this Agreement shall specify the volume, source and delivery period pertain- ing to the transaction. 2.4 Principal. The principal balance of the Notes shall be paid as follows: (a) The principal balance of the Notes remaining unpaid as of the Commitment Termination Date shall be payable in 10 forty-eight (48) monthly installments, commencing on Septem- ber 1, 1997, and continuing on the first (1st) day of each month thereafter through August 1, 2001 (the "Maturity"), as more fully described in the Notes (the "Term Loan"). (b) Except as herein provided, Borrowers may from time to time prepay, without penalty or premium, all or any part of the Notes. Amounts so prepaid prior to the Commitment Termination Date or amounts of the Line Commitment otherwise unused (subject to the other provisions of this Agreement) shall be available to re-advance or advance, as the case may be, as one or more advances under the Line Loan. Prepayments made on or after the Commitment Termination Date shall be applied first to interest and then to the outstanding principal balance of and principal installments due under the Notes in the inverse order of maturity. Each payment made pursuant to this Section 2.4(b) shall be in addition to, and not in lieu of, all other payments of principal, interest, fees, costs, expenses and other amounts otherwise required by the Notes. Nothing in this Section 2.4(b) shall affect the rights of the Agent or the Banks to require payment in full of the Notes prior to Maturity due to an acceleration of the Notes upon an Event of Default. (c) If at any time the aggregate amount of advances outstanding under the Line Loan plus the aggregate liability of the Banks under Letters of Credit outstanding at such time shall exceed the Borrowing Base then in effect, Borrowers shall, within thirty (30) days after the Agent gives Borrow- ers written notice of such excess, (a) pay the principal balance of the Notes in an amount which is equal to or greater than such excess, together with interest on the amount so paid, or (b) comply with the requirements of Section 4.2(a) hereof. If such payment is not received by the Agent on or before the last day of said thirty (30) day period, then notwithstanding Borrowers' compliance with clause (b) above within ninety (90) days after the end of said thirty (30) day period, Borrowers shall pay the amount of such excess, as increased or decreased since the last calculation thereof, together with interest on the amount so paid. Any payment made pursuant to the first two (2) sentences of this Section 2.4(c) shall be in addition to, and not in lieu of, all other payments of principal, interest, fees, costs, expenses and other amounts otherwise required and shall be applied first to interest and then to principal and, if such payment is made on or after the Commitment Termination Date, such payment shall be applied to principal installments due under the Notes, in the inverse order of their maturity. In the event the Agent does not receive such payment in full on or before the last day of said ninety (90) day period: (x) if such day occurs prior to the Commitment Termination Date, then, notwithstanding the terms of the Notes and this Agreement, all obligations of the Banks to 11 make advances under the Line Loan and the obligation of BOK to issue Letters of Credit shall immediately terminate, and the aggregate principal balance of the Notes outstanding on the last day of said ninety (90) day period shall be payable in forty-eight (48) equal monthly installments, commencing on the first (1st) day of the month immediately following the month in which the end of said ninety (90) day period occurs and continuing on the first (1st) day of each month thereaf- ter until paid, and (y) if such day occurs on or after the Commitment Termination Date, then such nonpayment shall constitute an Event of Default. 2.5 Interest. The Notes shall bear interest and be payable as follows: (a) Available Options. Except as hereinafter provided, during the period commencing on August 1, 1995 and continuing through the Commitment Termination Date, interest shall accrue on any past due interest and on that portion of the aggregate principal amount of the Notes from time to time outstanding (collectively the "Debt") according to the following matrix: Percentage that the Debt Bears to the Borrowing Base Rate of Interest Less than 50% Applicable Prime Rate or Libor Rate plus 1.75% 50% - up to but Applicable Prime Rate or not including 75% Libor Rate plus 2.00% 75% or more Applicable Prime Rate or Libor Rate plus 2.25% Except as hereinafter provided, during the period commencing on September 1, 1997, and continuing through Maturity, interest shall accrue on the Debt according to the following matrix: Percentage that the Debt Bears to the Borrowing Base Rate of Interest Less than 50% Applicable Prime Rate plus .25% or Libor Rate plus 2.00% 50% - up to but Applicable Prime Rate plus .25% not including 75% or Libor Rate plus 2.25% 75% or more Applicable Prime Rate plus .25% or Libor Rate plus 2.50% 12 In determining the percentage that the Debt bears to the Borrowing Base, the "Debt" and the "Borrowing Base" shall be the average of such respective amounts during the most recent calendar month preceding such determination. The Applicable Prime Rate option described above in the matrices is herein- after referred to as the "Prime Rate Option" and the Libor Rate interest option described above in the matrices is here- inafter referred to as the "Libor Rate Option". The Prime Rate Option shall be computed on the basis of a year of 365 or 366 days, as the case may be and the Libor Rate Option shall be based on a year of 360 days and actual days elapsed. (b) Operation of Options. At the end of any applicable Libor Rate Funding Period, the Borrowers may either: (i) repay all outstanding balances of principal and interest to which such Libor Rate Funding Period applies; or (ii) select the Prime Rate Option or the Libor Rate Option to apply to a portion or all of such amounts affected by such Libor Rate Funding Period. During an applicable Libor Rate Funding Period, the Borrowers may not prepay in part or in whole the outstanding principal balance of the Note to which such Libor Rate Option applies and the applicable Libor Rate Funding Period shall continue until the end of such period. If the Prime Rate Option is selected with respect to all or a portion of the Debt, then at any time, Unit, on behalf of the Borrowers may notify the Agent that the Borrowers wish to convert all or a portion of the Debt to the Libor Rate Option. In such event, such designated outstanding balances of principal on the Notes shall convert to the Libor Rate Option. As provided below in Section 2.5(g)(i), the Borrow- ers may prepay in part or in whole without premium or penalty the outstanding principal balance of the Notes to which such Prime Rate Option applies. At any time when the Borrowers shall select, convert to or renew the Libor Rate Option to apply to a portion or all of the Debt, it shall fix one or more periods of 30, 60, 90 or 180 days during which such Option shall apply (the "Libor Rate Funding Period") provided, that each Libor Rate Funding Period shall begin on a London Business Day. In order to select, convert to or renew the Libor Rate Option, Borrowers shall provide the Agent with the date, which shall be a Business Day, on which the Libor Rate Option is to be effective, which date shall not be less than two (2) Business Days after the date on which the Agent is so notified. (c) Interest Payment Dates. Interest shall be payable on the Debt to which the Prime Rate Option applies on the first (1st) day of each calendar month, commencing on September 1, 1995. Interest shall be payable on the Debt to 13 which a Libor Rate Option applies at the conclusion of the applicable Libor Rate Funding Period, provided, however, that in the event that a Libor Rate Period of 180 days is select- ed, interest shall be payable no less frequently than quarterly. (d) Interest Rate After Maturity. Notwithstanding the provisions of Sections 2.5(a), 2.5(b) and 2.5(c) hereof, after Maturity, whether by acceleration or otherwise, the Debt shall bear interest at the fluctuating per annum rate equal to the sum of five percent (5%) per annum plus the Applicable Prime Rate and shall be payable on demand. (e) Libor Rate Unascertainable - Impracticability. If (i) on any date on which a Libor Rate would otherwise be set the Agent shall have in good faith determined (which determination shall be conclusive) that: (A) adequate and reasonable means do not exist for ascertaining such Libor Rate, (B) a contingency has occurred which mate- rially and adversely affects the interbank euro- dollar market, or (C) the effective cost to the Banks of fund- ing a proposed Libor Rate Option from a Corre- sponding Source of Funds shall exceed the Libor Rate applicable to such Libor Rate Funding Period, or (ii) at any time the Banks shall have determined in good faith (which determination shall be conclusive) that the making, maintenance or funding of the Libor Rate Option has been made impracticable or unlawful by compliance by the Banks in good faith with any Law or guideline or interpretation or administration thereof by any Official Body charged with the interpretation or administration thereof or with any request or directive of any such Official Body (whether or not having the force of law); then, and in any such event, the Agent may notify the Borrowers of such determination. Upon such date as shall be specified in such notice (which shall not be earlier than the date such notice is given) the obliga- tion of the Agent to allow the Borrowers to select, convert to or renew the Libor Rate Option shall be suspended until the Agent shall have later notified the Borrowers of the Banks' determination in good faith (which determination shall be conclusive) that the 14 circumstances giving rise to such previous determination no longer exists. If the Agent notifies the Borrowers of a determi- nation under subsection (ii) of this Section 2.5(e), the Borrowers shall, as to the Libor Rate on the date speci- fied in such notice either convert the designated por- tion of the Debt covered by any Libor Rate Option to the Prime Rate Option in accordance with Section 2.5(f) hereof or prepay such amount in accordance with Section 2.5(g) hereof. Absent due notice from the Borrowers of conversion or prepayment, the Libor Rate automatically shall be converted to the Prime Rate Option upon such specified date. If at the time the Agent or the Banks make a determination under subsection (i) or (ii) of this Section 2.5(e) the Borrowers have previously notified the Agent that they wish to select, convert to or renew the Libor Rate Option with respect to a portion or all of the Debt but such Option has not yet gone into effect, such notification shall be deemed to provide for selection of, conversion to or renewal of the Prime Rate Option instead of the Libor Rate Option. (f) Conversion or Renewal of Interest Rate Options. (i) Subject to the provisions of subsection 2.5(h) below, Borrowers shall have the right to desig- nate or convert their option in accordance with the provisions hereof. Borrowers may elect to have an alternative option apply or continue to apply to all or a portion of the Debt. Each change in options shall be a conversion of the rate of interest applicable to the specified portion of the Debt. The option shall be designated or converted in the following manner: (A) at the expiration of any Libor Rate Funding Period with respect to any Libor Rate Option, or (B) on the date specified in a notice by the Agent pursuant to Section 2.5(e) hereof with respect to conversions from the Libor Rate Option. Whenever the Borrowers desire to convert or renew any interest rate option, the Borrowers shall provide the Agent with the following information: (C) the date, which shall be a Business Day, on which the proposed conversion or renewal is to be made which date shall not be less than two (2) 15 Business Days after the date on which Agent is so notified; and (D) the then applicable Option selected in accordance with Section 2.5(a) hereof. Notice having been so provided, after the date specified in such notice (telephonic or where applicable, in writ- ing) interest shall be calculated upon the designated portion of the Debt as so converted or renewed. (ii) Absent due notice from the Borrowers of conversion or renewal in the circumstances described in Section 2.5(f)(i)(A) hereof, the Libor Rate for which such notice is not received shall be converted automati- cally to the Prime Rate Option on the last day of the expiring fund period. (g) Prepayments. Subject to the provisions of Section 2.5(h) hereof, the Borrowers shall have the right at their option from time to time to prepay the Notes in whole or part without premium or penalty: (i) at any time with respect to the Prime Rate Option, (ii) at the expiration of any Libor Rate Funding Period with respect to prepayment of the Libor Rate Op- tion, or (iii) on the date specified in a notice by the Agent pursuant to Section 2.5(e) hereof with respect to the Libor Rate Option. Whenever the Borrowers desire to prepay any part of the Debt, they shall provide notice to the Agent in writing setting forth the following information: (iv) the date, which shall be a Business Day, on which the proposed prepayment is to be made; and (v) the aggregate principal amount of such prepayment, which shall be an integral multiple of $100,000. (h) Additional Compensation in Certain Circumstances. With respect to the portion of the Debt covered by the Libor Rate Option, if any: (i) if any Law or guideline or interpretation or application thereof by any Official Body charged with the interpretation or administration thereof or compli- 16 ance with any request or directive of any Official Body (whether or not having the force of law): (A) subjects the Banks to any tax or changes the basis of taxation with respect to this Agree- ment, the Notes, the Line Commitment or payments by the Borrowers of principal, interest or other amounts due from the Borrowers hereunder or under the Notes (except for taxes on the overall net income of the Banks imposed by the jurisdiction in which the Banks' principal office is located), (B) imposes, modifies or deems applicable any reserve, special deposit or similar require- ment against assets held by, credit extended by, deposits with or for the account of, or other acquisition of funds by, the Banks (other than requirements expressly included herein in the determination of the Libor Rate hereunder), or (C) imposes upon the Banks any other condi- tion or expense with respect to this Agreement, the Notes or its making, maintenance or funding of any part of the Line Commitment, the Notes or any security therefor, and the result of any of the foregoing is to increase the cost to, reduce the income receivable by or impose any expense (including loss of margin) upon the Agent or the Banks with respect to this Agreement, the Notes or the funding of any part of the Line Commitment by an amount which the Banks deem to be material (the Banks being deemed for this purpose to have made, maintained or funded each funding period of the applicable Libor Rate Option from a Corresponding Source of Funds), the Agent shall from time to time notify the Borrowers of the amount determined in good faith by the Banks (which determination shall be conclusive absent manifest or demonstrable error) to be necessary to compensate the Banks for such increase in cost, reduction in income or additional expense. Such amount shall be due and payable by the Borrowers to the Banks ten (10) Business Days after such notice is given. (ii) In addition to the compensation required by subsection (i) of this Section 2.5(h), the Borrowers shall indemnify the Banks against any loss or expense (including loss of margin) which the Banks have sus- tained or incurred as a consequence of any: (A) payment, prepayment or conversion of the applicable Libor Rate Option on a day other than the last day of the Libor Rate Funding Period 17 (whether or not such payment, prepayment or con- version is mandatory or automatic and whether or not such payment or prepayment is then due), or (B) attempt by the Borrowers to revoke (ex- pressly, by later inconsistent notices or other- wise) in whole or part any notice stated herein to be irrevocable (the Agent having in its sole discretion the options (A) to give effect to such attempted revocation and obtain indemnity under this Section 2.5(h) or (B) to treat such attempted revocation as having no force or effect, as if never made). If the Banks sustain or incur any such loss or expense, the Agent shall from time to time notify the Borrowers of the amount determined in good faith by the Banks (which determination shall be conclusive absent manifest or demonstrable error) to be necessary to indemnify the Banks for such loss or expense (the Banks being deemed for this purpose to have made, maintained or funded each Libor Rate Funding Segment of the applicable Libor Rate Option from a Corresponding Source of Funds). Such amount shall be due and payable by the Borrowers to the Agent for the benefit of the Banks ten (10) Business Days after such notice is given. 2.6 Commitment Fees. Borrowers jointly and severally agree to pay the Agent on behalf of the Banks, within ten (10) days of their receipt of the invoice therefor, commitment fees ("Commitment Fee" or "Commitment Fees"), payable in arrears. The Commitment Fees payable with respect to any Period shall be determined by applying the rate of one-half of one percent (1/2 of 1%) per annum to an amount which is equal to the unused portion of the lesser of (a) the Commitment Amount which is in effect during such Period or (b) the Borrowing Base. In the event the Commitment Amount is reduced during any Period, then the higher Commitment Fee shall be deemed to be in effect through the last day of the month in which such reduction occurs, and the reduced Commitment Fee shall be deemed to be in effect for the remainder of such Period. For purposes of this Section 2.6, the term "Period" shall mean each calendar quarter ending before the Commitment Termination Date. Commitment Fees shall be calculated on the basis of the actual number of days elapsed (365 or 366) in a year of 365 days. 2.7 Reductions in Commitment Amount. Borrowers may from time to time prior to the Commitment Termination Date but no more frequently than once per calendar quarter, upon at least five (5) days' prior written notice to the Agent signed by Unit on behalf of Borrowers, permanently reduce the Commitment Amount, but only upon repayment of the amount, if any, plus the interest accrued and unpaid thereon, by which the aggregate unpaid principal balance of 18 the Notes exceeds the reduced Commitment Amount. Any such change shall be in the amount of $100,000 or an integral multiple thereof. 2.8 Payments. All payments and prepayments of principal, interest, Commitment Fees and Letter of Credit Fees, shall be made as and when due hereunder by Borrowers to the Agent and applied by the Agent as set forth in the Intercreditor Agreement. ARTICLE III BORROWING BASE 3.1 Determination of Borrowing Base. The Borrowing Base shall be an amount equal to the following: (a) For the period beginning on the Closing Date and continuing through October 31, 1995: Fifty Million Dollars ($50,000,000); and (b) during each subsequent period beginning on a Redetermination Date, commencing with November 1, 1995 and ending on the day immediately preceding the next occurring Redetermination Date, the Loan Value, as hereinafter defined, as of the Redetermination Date which is the first day of such period. Ten (10) days prior to each Redetermination Date, the Agent shall make a determination of the loan value of the Current Collateral and the loan value of the Mineral Inter- ests (collectively, the "Loan Value"), subject to the approval of the other Banks as provided in this Section, and upon such determination the Agent shall promptly notify the other Banks in writing of its determination of the Loan Value. The determination of Loan Value made by the Agent shall be made by the Agent in the exercise of its sole discretion in accordance with the Agent's customary practices and standards for loans of this type. The other Banks may approve the Agent's determination of the Loan Value by written notice to the Agent within three (3) days of the Agent's notification of its determination of the new Loan Value and the Agent shall promptly notify the Borrowers of the Loan Value approved by the other Banks. If the other Banks fail to respond or fail to approve any such determina- tion of the Loan Value made by the Agent hereunder within such three (3) days, then the Loan Value shall be determined within an additional five (5) days by all of the Banks in their sole discretion in accordance with their respective customary practices and standards for loans of this type, which determination shall be in writing. 3.2 Increase in Borrowing Base. Unit may, at any time, on behalf of the Borrowers, submit a written request to the Agent that the Borrowing Base be increased to take into account assets acquired or proposed to be acquired by any of the Borrowers since 19 the then most recent determination of the Borrowing Base pursuant to Section 3.1 of this Agreement or this Section 3.2. Following receipt of such request and such descriptions, reports and other information the Banks may reasonably request with respect to such assets, such assets will be evaluated and a determination will be made whether to increase the Loan Value, and if so, by what amount, due to the acquisition or proposed acquisition of assets by the Borrowers using the method described above in Section 3.1(b). An increase in the Borrowing Base to a sum greater than the Commitment Amount shall not increase the Line Commitment without the separate and explicit approval of all of the Banks nor increase the individual commitment of any of the Banks without the prior approval of such Bank. Borrowers acknowledge that any increase in the Borrowing Base as a result of a proposed acquisition of assets shall not be effective until all of the Banks shall be reasonably satisfied that the condition of title to and the value of those assets is consistent with the descriptions, reports and other information provided by Unit or Borrowers with respect thereto, and Borrowers or Unit have, by contract or otherwise, obtained the right to acquire such assets. 3.3 Reduction of the Borrowing Base Upon Sales of Mineral Interests or Collateral. In the event of a sale, transfer, assignment, lease or other conveyance of any of the Collateral or Mineral Interests as permitted under this Agreement, the Borrowing Base may be reduced by an amount to be determined by the Agent with the approval of the other Banks in accordance with their respective customary standards for loans of this type on account of such sale, transfer, assignment, lease or other conveyance. ARTICLE IV SECURITY 4.1 Current Collateral. As security for the Indebtedness including Notes and the obligations of the Borrowers to reimburse BOK for drafts paid under Letters of Credit, Unit Drilling Co. hereby grants to the Agent as nominee and collateral agent for the Banks a continuing first priority security interest in, among other property described in the Security Agreement from Unit Drilling Co. to the Agent and dated as of even date herewith (the "Security Agreement"), (a) all of the drilling rigs and related equipment, inventory, parts, drill pipe, equipment, tools and supplies identified in Schedule 1 attached thereto, (b) all drilling rigs and related equipment acquired by Unit Drilling Co. after the date hereof and reflected on financial statements of Unit Drilling Co. as fixed assets, together with (c) all related parts, drill pipe, equipment, tools and supplies, (d) all additions and accessions thereto and replacements and substitutions thereof, and (e) all proceeds of any of the foregoing (collectively, the "Current Collateral"). 20 4.2 Additional Collateral. Subject to the occurrence of the events described below in Section 4.2(a) and 4.2(b), Borrowers shall grant to the Agent as nominee and collateral agent for the Banks a first mortgage lien on and security interest in all of Borrowers' Mineral Interests and related inventory, intangibles, accounts, equipment, fixtures and personal property (collectively referred to herein as the "Additional Collateral") to secure the Indebtedness, by instruments satisfactory to the Agent and the Banks, as follows: (a) No later than thirty (30) days after the Agent notifies Borrowers in writing that the aggregate amount of advances of the Line Loan outstanding at one time, plus the aggregate liability of BOK under Letters of Credit outstand- ing at such time, exceeds the Borrowing Base then in effect if, by the last day of said thirty (30) day period, Borrowers have not made a payment on the aggregate balance of the Notes in an amount equal to such excess, plus the unpaid accrued interest on the amount so paid as of the date of such payment. (b) No later than thirty (30) days after the Agent notifies Borrowers in writing that an Event of Default has occurred, unless the circumstances giving rise to such Event of Default have been cured prior to the lapse of such thirty (30) days. ARTICLE V CONDITIONS PRECEDENT TO LOANS 5.1 Conditions Precedent. The obligation of the Banks to make any advance under this Agreement and convert the same to the Term Loan on the Commitment Termination Date is subject to the satisfaction of all of the following conditions (in addition to the other terms and conditions set forth herein): (a) No Default. There shall exist no Event of Default or Default on the Closing Date. (b) Representations and Warranties. The representa- tions, warranties and covenants set forth in Article VII shall be true and correct on and as of the Closing Date and the Commitment Termination Date, respectively, with the same effect as though made on and as of the Closing Date and the Commitment Termination Date, respectively. (c) Certificates. Each of the Borrowers shall have delivered to the Agent a Certificate, dated as of the Closing Date, and signed by its President or Vice President and its Secretary or Assistant Secretary certifying (i) to the matters covered by the conditions specified in subsections 21 (a) and (b) of this Section 5.1, (ii) that it has performed and complied with all agreements and conditions required to be performed or complied with by it prior to or on the Closing Date, (iii) to the name and signature of each officer authorized to execute and deliver the Loan Documents and any other documents, certificates or writings and to borrow under this Agreement, and (iv) to such other matters in connection with this Agreement which the Banks shall reasonably deter- mine to be advisable. The Banks may conclusively rely on such Certificate until they receive notice in writing to the contrary. (d) Proceedings. On or before the Closing Date, all corporate proceedings of each of the Borrowers shall have been taken in connection with the transactions contemplated by the Loan Documents and shall be satisfactory in form and substance to the Agent and its counsel; and the Banks shall have received certified copies, in form and substance satis- factory to the Agent and its counsel, of the Articles or Certificate of Incorporation and Bylaws of the Borrowers and the resolutions of the Board of Directors of the Borrowers, as adopted, authorizing the execution and delivery of the Loan Documents and the borrowings under this Agreement. (e) Loan Documents/Security Instruments. The Borrowers shall have delivered to the Agent this Loan Agreement and the Security Agreement, each appropriately executed by the appropriate parties and, where applicable, acknowledged to the satisfaction of the Banks and dated as of the Closing Date, together with such financing statements, transfer orders, letters in lieu and other documents as shall be necessary and appropriate to perfect the security interests in the Current Collateral covered by said Security Instru- ments. (f) Notes. The Borrowers shall have delivered the Notes to the order of the Banks, appropriately executed. (g) Other Information. The Banks shall have received such other information, certificates, resolutions, documents and assurances as shall be reasonably requested by the Banks. ARTICLE VI COVENANTS The Borrowers covenant and agree with the Banks that from the date hereof and so long as this Agreement is in effect (by exten- sion, amendment or otherwise) and until payment in full of all Indebtedness and the performance of all other obligations of the Borrowers under this Agreement, unless the Banks shall otherwise consent in writing: 22 6.1 Payment of Taxes and Claims. The Borrowers will pay and discharge or cause to be paid and discharged all Taxes imposed upon the income or profits of the Borrowers or upon the property, real, personal or mixed, or upon any part thereof, belonging to Borrowers before the same shall be in default, and all lawful claims for labor, rentals, materials and supplies which, if unpaid, might become a Lien upon its property or any part thereof in excess of $500,000 in the aggregate at any time; provided however, that the Borrowers shall not be required to pay and discharge or cause to be paid or discharged any such Tax, assessment or claim so long as the validity thereof shall be contested in good faith by appropriate proceedings, and adequate book reserves shall be established with respect thereto, and the Borrowers shall pay such Tax, charge or claim before any property subject thereto shall become subject to execution. 6.2 Maintenance of Existence. Each of the Borrowers will use its best efforts to preserve and keep in full force and effect its corporate existence, rights and franchises and will continue to conduct and operate its business substantially as being conducted and operated presently. Each of the Borrowers will become and remain qualified to conduct business in each jurisdiction where the nature of the business or ownership of property by such Borrowers may require such qualification. Notwithstanding the provisions of this Section, the Banks acknowledge that Roundup Resources, Inc. may be merged into Unit Petroleum Company and consent to such merger. 6.3 Preservation of Property. Each of the Borrowers will use its best efforts at all times to maintain, preserve and protect all of its properties which are used or useful in the conduct of its respective businesses whether owned in fee or otherwise, or leased, in good repair and operating condition; from time to time make, or cause to be made, all needful and proper repairs, renewals, replacements, betterments and improvements thereto so that the business carried on in connection therewith may be properly and advantageously conducted at all times; and comply with all material leases to which it is a party or under which it occupies property so as to prevent any material loss or forfeiture thereunder. 6.4 Insurance. To the extent possible, each of the Borrowers will keep or cause to be kept adequately insured by financially sound and reputable insurers Borrowers' property of a character usually insured by businesses engaged in the same or similar businesses, including the Collateral. Upon demand by the Agent or any of the Banks any insurance policies covering the Collateral shall be endorsed to provide for payment of losses to the Agent as its interest may appear, to provide that such policies may not be canceled, reduced or affected in any manner for any reason without thirty (30) days prior notice to the Banks. 23 6.5 Compliance with Applicable Laws. Each of the Borrowers will comply in all material respects with the requirements of all applicable Laws and orders of any Tribunal and obtain any licenses, permits, franchises or other governmental authorizations necessary to the ownership of Borrowers' properties or to the conduct of Borrowers' businesses. 6.6 Environmental Covenants. Upon its receipt, each of the Borrowers will immediately notify the Agent of and provide the Agent with copies of any notifications of discharges or releases or threatened releases or discharges of a Polluting Substance on, upon, into or from properties owned by Borrowers which are given or required to be given by or on behalf of the Borrowers to any federal, state or local Tribunal if any of the foregoing may materially and adversely affect Borrowers or any material part of their properties, and such copies of notifications shall be delivered to the Agent at the same time as they are delivered to the Tribunal. Borrowers further agree to promptly undertake and diligently pursue to completion any appropriate and legally required or authorized remedial containment and cleanup action in the event of any release or discharge or threatened release or dis- charge of a Polluting Substance on, upon, into or from the Borrowers' Mineral Interests which are under the control of Borrowers. To the extent required by applicable law, each of the Borrowers will maintain and retain complete and accurate records of all releases, discharges or other disposal of Polluting Substances on, onto, into or from Borrowers' Mineral Interests which are under the control of Borrowers, including, without limitation, records of the quantity and type of any Polluting Substances disposed of on or off such properties. 6.7 Environmental Indemnities. Each of the Borrowers hereby agree to indemnify, defend and hold harmless the Banks and their respective officers, directors, employees, agents, consultants, attorneys, contractors and their respective affiliates, successors or assigns, or transferees from and against, and reimburse said Persons in full with respect to, any and all loss, liability, damage, fines, penalties, costs and expenses, of every kind and character, including reasonable attorneys' fees and court costs, known or unknown, fixed or contingent, occasioned by or associated with any claims, demands, causes of action, suits and/or enforce- ment actions, including any administrative or judicial proceedings, and any remedial, removal or response actions ever asserted, threatened, instituted or requested by any Persons, including any Tribunal, arising out of or related to: (a) the breach of any representation or warranty of Borrowers contained in Section 7.7 set forth herein; (b) the failure of Borrowers to perform any of their respective covenants contained in Section 6.5 or 6.6 hereunder; (c) the ownership, construction, occupancy, operation, use of the Borrowers' properties prior to the earlier of the date on which (i) the Indebtedness and obligations secured hereby have been paid and performed in full and the Security Instruments have been released, or (ii) the Borrowers' properties has been sold by 24 Agent or by the Banks following such parties' ownership of the Borrowers' properties by way of foreclosure of the Liens granted pursuant hereto, deed in lieu of such foreclosure or otherwise (the "Release Date"); provided, however, this indemnity shall not apply with respect to matters caused by or arising solely from the Agent's or the Banks' activities during any period of time the Agent or the Banks acquire ownership of the Borrowers' properties. The indemnities contained in this Section 6.7 apply, without limitation, to any violation on or before the Release Date of any Environmental Laws and any liability or obligation relating to the environmental conditions on, under or about the Borrowers' properties on or prior to the Release Date (including, without limitation: (a) the presence on, upon or in the Borrowers' properties or release, discharge or threatened release on, upon or from the Borrowers' properties of any Polluting Substances generated, used, stored, treated, disposed of or otherwise released prior to the Release Date, and (b) any and all damage to real or personal property or natural resources and/or harm or injury including wrongful death, to persons alleged to have resulted from such release of any Polluting Substances regardless of whether the act, omission, event or circumstances constituted a violation of any Environmental Law at the time of its existence or occurrence). The term "release" shall have the meaning specified in CERCLA/SARA and the terms "stored," "treated" and "disposed" shall have the meanings specified in RCRA/HSWA; provided, however, any broader meanings of such terms provided by applicable laws of the State of Oklahoma shall apply. The provisions of this Section 6.7 shall be in addition to any other obligations and liabilities Borrowers may have to the Agent or the Banks at common law and shall survive the Release Date and shall continue thereafter in full force and effect. The Agent and the Banks agree that in the event that such claim, suit or enforcement action is asserted or threatened in writing or instituted against them or any of their officers, employers, agents or contractors or any such remedial, removal or response action is requested of them or any of their officers, employees, agents or contractors for which the Agent or the Banks may desire indemnity or defense hereunder, the Agent or the Banks shall give written notification thereof to the Borrowers. Notwithstanding anything to the contrary stated herein, the indemnities created by this Section 6.7 shall only apply to losses, liabilities, damages, fines, penalties, costs and expenses actually incurred by the Agent or the Banks as a result of claims, demands, actions, suits or proceedings brought by Persons who are not the beneficiaries of any such indemnity. The Agent or the Banks shall act as the exclusive agent for all indemnified Persons under this Section 6.7. With respect to any claims or demands made by such indemnified Persons, the Agent shall notify the Borrowers within thirty (30) days after the Agent's receipt of a writing advising 25 the Agent of such claim or demand. Such notice shall identify (i) when such claim or demand was first made, (ii) the identity of the Person making it, (iii) the indemnified Person and (iv) the substance of such claim or demand. Failure by the Agent to so notify the Borrowers within said thirty (30) day period shall reduce the amount of the Borrowers' obligations and liabilities under this Section 6.7 by an amount equal to any damages or losses suffered by the Borrowers resulting from any prejudice caused the Borrowers by such delay in notification from the Agent. Upon receipt of such notice, the Borrowers shall have the exclusive right and obligation to contest, defend, negotiate or settle any such claim or demand through counsel of their own selection (but reasonably satisfactory to the Agent and the Banks) and solely at Borrowers' own cost, risk and expense; provided, that the Agent and the Banks, at their own cost and expense, shall have the right to participate in any such contest, defense, negotiations or settle- ment. The settlement of any claim or demand hereunder by the Borrowers, unless such settlement fully releases the Banks from any and all liability thereon, may be made only upon the prior approval of the Banks of the terms of the settlement, which approval shall not be unreasonably withheld. 6.8 Financial Statements and Reports. The Borrowers shall deliver the following to each of the Banks: (a) As soon as available and in any event within forty-five (45) days after the end of each of the first three fiscal quarters of each fiscal year of Unit, (i) Unaudited balance sheets of Unit and its consolidated subsidiaries, prepared on a consolidated basis, as of the end of such quarterly period; and (ii) Unaudited statements of income of Unit and its consolidated subsidiaries, prepared on a consolidat- ed basis, for the portion of such fiscal year ended with such quarterly period setting forth in detail, in each case, figures derived on a consistent basis and present- ed in comparative form for the corresponding periods of the previous fiscal year. (b) As soon as available and in any event within one hundred twenty (120) days following the close of each fiscal year of Unit: (i) Audited balance sheets of Unit and its consolidated subsidiaries, prepared on a consolidated basis, as of the end of such year; (ii) Audited statements of income of Unit and its consolidated subsidiaries, prepared on a consolidated basis, for the year then ended; and 26 (iii) Audited statements of shareholders' equity and cash flows of Unit and its consolidated subsidiar- ies, prepared on a consolidated basis, for such year setting forth, in each case, figures derived on a consistent basis and presented in comparative form for the previous fiscal year. (c) Concurrently with the furnishing of the annual audited financial statements pursuant to Section 6.8(b), (i) a separate certificate of the independent certified public accountants (such certified public accountants must be nationally recognized) who audited and prepared such state- ments, stating that the statements were prepared in conformi- ty with GAAP on a consistent basis (except for such varia- tions as are noted and approved by such independent certified public accountants), and fairly present the consolidated financial condition of Unit and its consolidated subsidiar- ies, which certificate shall not be qualified or limited because of restricted or limited examination by such accoun- tants of any material portion of the records of Unit or any of its subsidiaries; and (ii) written computations, signed by the Controller or Treasurer of Unit, of the ratios and amounts described in Sections 6.18(A), 6.20, 6.23, 6.24, 6.25, 6.26 and 6.27 hereof; and five (5) copies of the 10-K statement of Unit and its consolidated subsidiaries filed with the Securities and Exchange Commission for such fiscal year. (d) Concurrently with the furnishing of the quarterly statements pursuant to Section 6.8(a) hereof, there shall be furnished to each of the Banks: (a) a certificate signed by the Treasurer or Controller of Unit stating to the best of his knowledge after performance of due diligence: (i) that the statements were prepared (subject to year-end audit adjustments) in conformity with GAAP, applied on a consistent basis (except for adjustments with which the independent certified public accountants preparing such annual audited financial statements concur); (ii) that a review of the activities of each of the Borrowers for the period covered by the financial statements has been made under his supervision with a view to determining whether each of the Borrowers has kept, observed, performed and fulfilled all its obligations under the Agreement, the Notes and other Loan Documents to which it is a party; and (iii) that each of the Borrowers has kept, observed and fulfilled each and every obligation under this Agreement, the Notes and other Loan Documents to which it is a party, and is not at that time in default in the observance, performance or fulfillment of any such obliga- tions, or if any of the Borrowers shall be in default, specifying in said certificate such default and the nature, period of existence and status thereof; (b) a written report (i) naming the operator and the location (state and county) of each drilling rig included in the Collateral as of the end 27 of such quarter, and (ii) describing in reasonable detail any material disposition or substitution of any of the Collater- al; (c) computations of the ratios and amounts described in Sections 6.18(A), 6.20, 6.23, 6.24, 6.25, 6.26 and 6.27 hereof; and (d) five (5) copies of the 10-Q statement of Unit and its consolidated subsidiaries filed with the Securities and Exchange Commission with respect to such quarter. (e) As soon as available but in no event later than March 31 of each year, Borrowers shall deliver to each of the Banks one copy of a report, prepared by Borrowers' in-house engineers, in form and substance satisfactory to Agent (and, if requested in writing by the Agent at the direction of the Majority Banks), audited by an independent petroleum engineer selected by Borrowers and satisfactory to the Majority Banks, setting forth the proven oil and gas reserves of Borrowers' Mineral Interests, the projection of the rate of production and net operating income with respect thereto, as of December 31 of the immediately preceding year. As soon as available, Borrowers shall deliver to each of the Banks a copy of a report, prepared by Borrowers' in-house engineers, in form and substance satisfactory to Agent and based on the best information available to Borrower at the time, setting forth information regarding any over-balancing or under-balancing of natural gas that totals 50,000 or more mcf per well and a statement as to the aggregate amount of over-balancing or under-balancing for all of Borrowers' wells. 6.9 Notice of Default. With reasonable promptness after the happening of any condition or event which constitutes an Event of Default or Default, Unit will give the Agent a written notice thereof specifying the nature and period of existence thereof and what actions, if any, the Borrowers are taking and propose to take with respect thereto. 6.10 Notice of Litigation. With reasonable promptness after becoming aware of the existence of any action, suit or proceeding at law or in equity before any Tribunal, an adverse outcome in which would (i) materially impair the ability of any of the Borrowers to carry on their business substantially as now conduct- ed, (ii) materially and adversely affect the condition (financial or otherwise) of any of the Borrowers, or (iii) result in monetary damages in excess of $1,000,000, the Borrowers will give the Agent a written notice specifying the nature thereof and what actions, if any, the Borrowers are taking and propose to take with respect thereto. 6.11 Requested Information. With reasonable promptness, the Borrowers will give the Agent or the Banks such other data and information as from time to time may be reasonably requested by the Agent or any of the Banks. 6.12 Inspection. Borrowers will keep complete and accurate books and records with respect to the Collateral and their other properties, business and operations and will permit employees and 28 representatives of the Banks, upon reasonable notice, to audit, inspect and examine all such books and records, with the exception of the portion thereof covered by an attorney-client privilege or constituting attorney work product, and to make copies thereof and extracts therefrom during normal business hours. Upon any Default or Event of Default of the Borrowers, they will surrender all of such records relating to the Collateral to the Agent or the Banks upon receipt of any request therefor from the Agent or the Banks. 6.13 Maintenance of Employee Benefit Plans. The Borrowers will maintain each employee benefit plan as to which they may have any liability or responsibility in compliance with ERISA and all other Laws applicable thereto. 6.14 Limitation on Liens. Borrowers will not create or suffer to exist any Lien upon any of their properties or assets except (i) Liens in favor of the Agent securing the Indebtedness; (ii) pledges, deposits or Liens not delinquent under workmen's compensation, unemployment insurance or similar statutes, mechanics', landlords', workmen's, repairmen's, materialmen's, carriers' liens and liens of operators of, and participants in, any oil, gas or mineral properties of any of the Borrowers or other similar liens arising in the ordinary course of business (includ- ing, without limitation, Liens in existence as of the date hereof which arose in connection with gas purchase settlements), or deposits or pledges to obtain the release of any such Liens so long as such Liens do not include any deposits, advances, borrowed money or the deferred purchase price of property or services; (iii) Liens for taxes, assessments, governmental charges or levies, not yet due or delinquent or which can thereafter be paid without penalty, and statutory liens which do not and will not materially impair the use of the property of any of the Borrowers or the value of such property for the purposes of its business unless, as to all Liens described above for amounts due and owing, such Liens are being contested in good faith by appropriate proceedings in such a manner as not to permit the foreclosure of such Liens and Liens, judgments or awards pending appeal, if, as to all the preceding matters referred to in this Section 6.14(iii), in the opinion of the Banks adequate reserves are set aside and maintained with respect thereto; and (iv) Liens expressly permitted to exist under the terms of any of the Security Instruments; and (v) consensual liens or security interests in gas compressor equipment of Borrowers. 6.15 Disposition/Negative Pledge Regarding Encumbrance of Collateral and Other Assets. Borrowers will not sell or encumber any of the Current Collateral or any of the Additional Collateral pledged or mortgaged to the Agent as provided in Section 4.2 of this Agreement and Borrowers will not sell, lease, transfer, scrap or otherwise dispose of or mortgage, pledge, grant a security interest in or otherwise encumber any of Borrowers' other proper- ties or assets, whether for replacement or not, unless such sale or disposition shall be in the ordinary course of business and for a reasonable value, without obtaining the prior consent of the Banks. 29 In no event shall Borrowers cause or permit the voluntary pledge, mortgage or other encumbrance, attachment or levy of or against any of the properties or assets of whatsoever nature or type to any Person (financial institution or otherwise). 6.16 Other Agreements. Borrowers will not enter into or permit to exist any agreement (i) which would cause an Event of Default or a Default hereunder; or (ii) which contains any provision which would be violated or breached by the performance of Borrowers' obligations hereunder or under any of the other Loan Documents. 6.17 Limitation on Other Indebtedness. The Borrowers will not create, incur, assume, become or be liable in any manner in respect of, or suffer to exist, any indebtedness whether evidenced by a note, bond, debenture, agreement, letter of credit or similar or other obligation, or accept any deposits or advances of any kind, except (i) plugging bonds, surface damage bonds, bonds with respect to self insured workers compensation insurance or bonds, undertakings or contracts and obligations for trade payables and current indebtedness (other than for borrowed money) incurred in, and deposits and advances accepted in, the ordinary course of business; (ii) indebtedness not to exceed $200,000 per calendar year incurred for the acquisition of assets secured by purchase money security interests; (iii) usual and customary insurance premiums financed in the normal course of business; and (iv) the Indebtedness. 6.18 Contingent Liabilities; Advances. Except for (A) guarantees by Unit of indebtedness of a Person or Persons up to the aggregate amount of $200,000; (B) guarantees for the repayment of any indebtedness owed by one of the Borrowers to another one of the Borrowers; (C) the obligation of any Borrower to repurchase any property or interests under any partnership agreement under which any of the Borrowers serves as general partner up to the aggregate annual amount of $500,000 or (D) Unit's $2,000,000 guarantee of the $6,000,000 line of credit of GED Gas Services, L.L.C. established with F&M Bank and Trust Company; the Borrowers will not either directly or indirectly, (i) guarantee, become surety for, discount, endorse, agree (contingently or otherwise) to purchase, repurchase or otherwise acquire or supply or advance funds in respect of, or otherwise become or be contingently liable upon the indebtedness, obligation or liability of any Person, (ii) guarantee the payment of any dividends or other distributions upon the stock of any corporation, (iii) discount or sell with recourse or for less than the face value thereof, any of its notes receivable, accounts receivable or chattel paper; (iv) loan, agree to loan, or advance money to any Person; or (v) enter into any agreement for the purchase or other acquisition of any goods, products, materials or supplies, or for the making of any shipments or for the payment of services, if in any such case payment therefor is to be made regardless of the non-delivery of such goods, products, materials or supplies or the non-furnishing of the transportation of 30 services; provided, however that the foregoing shall not be applic- able to endorsement of negotiable instruments presented to or deposited with a bank for collection or deposit in the ordinary course of business. 6.19 Merger, Consolidation, Acquisition. None of the Bor- rowers will merge or consolidate with or into any other Person with the exception of a merger of Roundup Resources, Inc. into Unit Petroleum Company; or permit any other Person to consolidate with or merge into any of the Borrowers; or adopt or effect any plan of reorganization, recapitalization, liquidation or dissolution; provided, however, Borrowers may enter into letter(s) of intent pertaining to merger, consolidation or acquisition subject to obtaining the Banks' written consent thereto prior to consummation of the transactions contemplated by such letter(s) of intent. 6.20 Dividends. The Borrowers will not permit Unit to pay dividends (other than stock dividends) on or make any other distribution on account of any class of its capital stock or purchase or retire any class of its capital stock, unless such purchase or retirement is made by substituting another class of capital stock, whether now or hereafter existing, except cash dividends of not more than twenty-five percent (25%) of Unit's consolidated after-tax profits, as reflected in the financial statements furnished to the Agent pursuant to this Agreement for Unit's immediately preceding fiscal year, and only if Working Capital Provided from Operations during said year is equal to or greater than 175% of Current Maturities of Long Term Debt at the end of such year. 6.21 Articles of Incorporation and By-Laws. The Borrowers will not amend, alter, modify or restate their Articles or Certificates of Incorporation or By-Laws in any way which would in any manner adversely affect the Borrowers' obligations or covenants to the Banks hereunder. 6.22 Assumed Names. The Borrowers promptly shall advise the Agent if any of the Borrowers amend, alter, modify or restate their Articles or Certificates of Incorporation or Bylaws in any way which would change the corporate name or adopt a trade name for any of the Borrowers. 6.23 Current Ratio. The Borrowers will not permit the Current Ratio to be less than 1.0 to 1.0 on any quarterly or annual reporting date. 6.24 Minimum Tangible Net Worth. The Borrowers will not permit the Consolidated Tangible Net Worth to be less than Forty Eight Million Dollars ($48,000,000). 6.25 Minimum Cash Flow. The Borrowers will not permit Working Capital provided from Operations during any fiscal year to be less than Twelve Million Dollars ($12,000,000). 31 6.26 Long Term Debt to Consolidated Tangible Net Worth Ratio. The Borrowers will not permit the ratio of the Long Term Debt to Consolidated Tangible Net Worth to exceed 1.0 to 1.0 on any quarterly or annual reporting date. 6.27 Total Liabilities to Consolidated Tangible Net Worth Ratio. The Borrowers will not permit the ratio of Total Liabili- ties to Consolidated Tangible Net Worth to exceed 1.25 to 1.00 on any quarterly or annual reporting date. ARTICLE VII REPRESENTATIONS AND WARRANTIES To induce the Banks to enter into this Agreement and to make the Line Loan and the Term Loan to the Borrowers under the provisions hereof, and in consideration thereof, the Borrowers represent, warrant and covenant as follows: 7.1 Organization and Qualification. Each of the Borrowers is duly organized, validly existing, and in good standing under the Laws of its respective jurisdiction of incorporation, and is duly licensed and in good standing as a foreign corporation in each jurisdiction in which the nature of the business transacted or the property owned is such as to require licensing or qualification as such, except where failure to be licensed or in good standing would not have a material adverse affect on any of the Borrowers. 7.2 Litigation. There is no action, suit, investigation or proceeding threatened or pending before any Tribunal against or affecting any of the Borrowers or any properties or rights of the Borrowers, which, if adversely determined, would result in a liability of greater than $1,000,000 or would otherwise result in any material adverse change in the business or condition, financial or otherwise, of Borrowers that is not otherwise covered by adequate insurance. None of the Borrowers is in default with respect to any judgment, order, writ, injunction, decree, rule or regulation of any Tribunal. 7.3 Conflicting Agreements and Other Matters. None of the Borrowers is in default in any material respect in the performance of any obligation, covenant, or condition in any agreement to which it is a party or by which it is bound. None of the Borrowers is a party to any contract or agreement or subject to any charter or other restriction which materially and adversely affects its business, property or assets, or financial condition, other than permitted under this Agreement. None of the Borrowers is a party to or otherwise subject to any contract or agreement which restricts or otherwise affects the right or ability of the Bor- rowers to execute the Loan Documents or the performance of any of their respective terms. Neither the execution nor delivery of any of the Loan Documents nor fulfillment of nor compliance with their 32 respective terms and provisions will conflict with, or result in a breach of the terms, conditions or provisions of, or constitute a default under, or result in any violation of, or result in the creation of any Lien (except those created by the Loan Documents) upon any of the properties or assets of the Borrowers pursuant to, or require any consent, approval or other action by or any notice to or filing with any Tribunal (other than routine filings after the Closing Date with the Securities and Exchange Commission, any securities exchange and/or state blue sky authorities) pursuant to the Charter or By-Laws of any of the Borrowers, any award of any arbitrator, or any agreement, instrument or Law to which any of the Borrowers is subject. 7.4 Financial Statements. The Borrowers' most recent unaudited financial statements which have been furnished to the Banks have been prepared in conformity with GAAP, show all material liabilities, direct and contingent, and fairly present the financial condition of the Borrowers and the results of their operations for the periods then ended, and since such date there has been no material adverse change in the business, financial condition or operations of the Borrowers. 7.5 Corporate Authorization. The Boards of Directors of the Borrowers have duly authorized the execution and delivery of each of the Loan Documents and the performance of their respective terms. No other consent of any other Person, except for the Banks, is required as a prerequisite to the validity and enforceability of the Loan Documents. 7.6 Title to Properties; Authority. Each of the Borrowers has full power, authority and legal right to own and operate the properties which it now owns and operates, and to carry on the lines of business in which it is now engaged, and Unit Drilling Company has good and marketable title to the Current Collateral subject to no Lien of any kind except Liens permitted by this Agreement. Borrowers have full power, authority and legal right to execute and deliver and to perform and observe the provisions of this Agreement and the other Loan Documents. 7.7 Environmental Representations. To the best of Bor- rowers' knowledge: (a) None of the Borrowers is subject to any liability or obligation relating to (i) the environmental conditions on, under or about their properties, including, without limitation, the soil and ground water conditions at the location of any of the Borrowers' properties, or (ii) the use, management, handling, transport, treatment, generation, storage, disposal, release or discharge of any Polluting Sub- stance that would or may reasonably be expected to result in a liability in the amount of $1,000,000 or more; 33 (b) The Borrowers have been issued and are in compli- ance with all material permits, licenses or similar authori- zations to construct, occupy, operate or use any buildings, improvements, facilities, fixtures and equipment forming a part of their properties by reason of any Environmental Laws; (c) Each of the Borrowers has taken all steps necessary to determine and has determined that no Polluting Substances have been disposed of or otherwise released on, onto, into, or from their operated Mineral Interests (the term "release" shall have the meanings specified in CERCLA/SARA, and the term "disposal" or "disposed" shall have the meanings speci- fied in RCRA/HSWA) which singly has, or in the aggregate have resulted in, or may reasonably be expected to result in a liability in the amount of $1,000,000 or more; provided, in the event either CERCLA/SARA or RCRA/HSWA is amended so as to broaden the meaning of any term defined thereby, such broader meaning shall apply subsequent to the effective date of such amendment and provided further, to the extent that the laws of any State or Tribunal establish a meaning for "release," "disposal" or "disposed" which is broader than that specified in CERCLA/SARA, RCRA/HSWA or other Environmental Laws, such broader meaning shall apply); (d) There are no PCB's or asbestos-containing materi- als, whether in the nature of thermal insulation products such as pipe boiler or breech coverings, wraps or blankets or sprayed-on or trowelled-on products in, on or upon the properties owned by Borrowers; and (e) There is no urea formaldehyde foam insulation ("UFFI") in, on or upon the properties owned by Borrowers. 7.8 Purposes. None of the Borrowers is engaged principally, or as one of its important activities, in the business of extending credit for the purpose of purchasing or carrying margin stock (within the meaning of Regulation U of the Board of Governors of the Federal Reserve System) and no part of the proceeds of any borrowing hereunder will be used to purchase or carry any margin stock or to extend credit to others for the purpose of purchasing or carrying any margin stock. If requested by the Agent or any of the Banks, the Borrowers will furnish to the Agent or such Bank a statement in conformity with the requirements of Federal Reserve Form U-1, referred to in Regulation U, to the foregoing effect. None of the Borrowers nor any agent acting on their behalf has taken or will take any action which might cause this Agreement or the Notes to violate any regulation of the Board of Governors of the Federal Reserve System (including Regulations G, T, U and X) or to violate any Securities Laws, state or federal, in each case as in effect now or as the same may hereafter be in effect. 7.9 Compliance with Applicable Laws. Each of the Borrowers is in compliance in all material respects with all Laws, ordinanc- 34 es, rules, regulations and other legal requirements applicable to it and the business conducted thereby, the violation of which could or would have a material adverse effect on its business condition, financial or otherwise. 7.10 Possession of Franchises, Licenses. Each of the Bor- rowers possesses all franchises, certificates, licenses, permits and other authorizations from governmental political subdivisions or regulatory authorities, free from burdensome restrictions, that are necessary in any material respect for the ownership, mainte- nance and operation of its properties and assets, and none of the Borrowers is in violation of any thereof in any material respect. 7.11 Leases, Easements and Rights of Way. Each of the Borrowers enjoys peaceful and undisturbed possession of all leases, easements and rights of way necessary in any material respect for the operation of its respective properties and assets. All such leases, easements and rights of way are valid and subsisting and are in full force and effect. 7.12 Taxes. Borrowers have filed all Federal, state and other income tax returns which are required to be filed and have paid all Taxes, as shown on said returns, and all Taxes due or payable without returns and all assessments received to the extent that such Taxes or assessments have become due. All Tax liabili- ties of the Borrowers are adequately provided for on the books of the Borrowers, including any interest or penalties. No income tax liability of a material nature has been asserted by taxing authorities for Taxes in excess of those already paid. 7.13 Disclosure. Neither this Agreement nor any other Loan Document or writing furnished to the Agent or the Banks by or on behalf of the Borrowers in connection herewith contains any untrue statement of a material fact nor do such Loan Documents and writ- ings, taken as a whole, omit to state a material fact necessary in order to make the statements contained herein and therein not misleading. There is no fact known to Borrowers and not reflected in the financial statements provided to the Banks which materially adversely affects their assets or in the future may materially adversely affect the business, properties, assets or financial condition of Borrowers which has not been set forth in this Agreement, in the Loan Documents or in other documents furnished to the Banks by or on behalf of the Borrowers prior to the date hereof in connection with the transactions contemplated hereby. 7.14 Investment Company Act Representation. None of the Borrowers is an "investment company" or a company "controlled" by an "investment company", within the meaning of the Investment Company Act of 1940, as amended. 7.15 ERISA. Since the effective date of Title IV of ERISA, no Reportable Event has occurred with respect to any Plan. For the purposes of this section the term "Reportable Event" shall mean an 35 event described in Section 4043(b) of ERISA. For the purposes hereof the term "Plan" shall mean any plan subject to Title IV of ERISA and maintained for employees of the Borrowers, or of any member of a controlled group of corporations, as the term "con- trolled group of corporations" is defined in Section 1563 of the Internal Revenue Code of 1986, as amended (the "Code"), of which any of the Borrowers is a part. Each Plan established or main- tained by any of the Borrowers is in material compliance with the applicable provisions of ERISA, and the Borrowers have filed all reports required by ERISA and the Code to be filed with respect to each Plan. The Borrowers have met all requirements with respect to funding Plans imposed by ERISA or the Code. Since the effective date of Title IV of ERISA there have not been any nor are there now existing any events or conditions that would permit any Plan to be terminated under circumstances which would cause the lien provided under Section 4068 of ERISA to attach to the assets of the Borrowers. The value of each Plan's benefits guaranteed under Title IV of ERISA on the date hereof does not exceed the value of such Plan's assets allocable to such benefits on the date hereof. 7.16 Fiscal Year. The fiscal years of the respective Bor- rowers end as of December 31 of each year. ARTICLE VIII EVENTS OF DEFAULT 8.1 Events of Default. The occurrence of any one or more of the following events shall constitute an Event of Default (whether such occurrence shall be voluntary or involuntary or come about or be effected by operation of Law or otherwise): (a) The Borrowers shall fail to make any payment due on any of the Notes within ten (10) Business Days after the same shall become due and payable (whether by extension, renewal, acceleration, maturity or otherwise) or the Borrowers shall fail to pay any other sums due to the Banks hereunder within ten (10) Business Days after the same shall become due and payable; or (b) Any representation or warranty of the Borrowers made herein or in any writing furnished in connection with or pursuant to any of the Loan Documents shall have been false or misleading in any material respect on the date when made; or (c) Any of the Borrowers shall fail to duly observe, perform or comply with any covenant, agreement or term (other than payment provisions which are governed by Section 8.1(a) hereof) contained in this Agreement or any of the Loan Documents and such default or breach shall have not been 36 cured or remedied within the earlier of thirty (30) days after any of the Borrowers shall know (or should have known) of its occurrence or thirty (30) days following receipt of notice thereof from the Bank; or (d) Any of the Borrowers shall default in the payment of principal or of interest on any other obligation for money borrowed or received as an advance (or any obligation under any conditional sale or other title retention agreement, or any obligation issued or assumed as full or partial payment for property whether or not secured by purchase money Lien, or any obligation under notes payable or drafts accepted representing extensions of credit) beyond any grace period provided with respect thereto, or shall default in the performance of any other agreement, term or condition contained in any agreement under which such obligation is created (or if any other default under any such agreement shall occur and be continuing beyond any period of grace provided with respect thereto) if the effect of such default is to cause, or to permit the holder or holders of such obligation (or a trustee on behalf of such holder or holders) to cause such obligation to become due prior to its date of maturity; or (e) Any of the following: (i) any of the Borrowers shall become insolvent or unable to pay its debts as they mature, make an assignment for the benefit of creditors or admit in writing its inability to pay its debts generally as they become due or fail generally to pay its debts as they mature; or (ii) an order, judgment or decree is entered adjudicating any of the Borrowers insolvent or an order for relief under the United States Bankruptcy Court is entered with respect to any of the Borrowers within sixty (60) days of the date of its entry; or (iii) any of the Borrowers shall petition or apply to any Tribunal for the appointment of a trustee, receiver, custodian or liquidator of any of the Borrowers or of any substantial part of the assets of any of the Borrowers, or shall commence any proceedings relating to any of the Borrowers under any bankruptcy, reorganization, compromise, arrangement, insolvency, readjustment of debts, dissolution, or liquidation Law of any jurisdiction, whether now or hereafter in effect; or (iv) any such petition or application shall be filed, or any such proceedings shall be commenced, of a type described in subsection (iii) above, against any of the Borrowers and any of the Borrowers by any act shall indicate its approval thereof, consent thereto or acquiescence therein, or an order, judgment or decree shall be entered appointing any such trustee, receiver, custodian or liquidator, or approving the petition in any such proceed- ings, and such order, judgment or decree shall remain unstayed and in effect, if being vigorously contested, for more than sixty (60) days; or (v) any order, judgment or decree shall be entered in any proceedings against any of the 37 Borrowers decreeing the dissolution of any of the Borrowers and such order, judgment or decree shall remain unstayed and in effect for more than thirty (30) days; or (vi) any final order, judgment or decree shall be entered in any proceedings against any of the Borrowers decreeing a split-up of any of the Borrowers which requires the divestiture of a substantial part of the assets of any of the Borrowers, and such order, judgment or decree shall remain unstayed and in effect for more than sixty (60) days; or (vii) any of the Borrowers shall fail to make timely payment or deposit of any amount of tax required to be withheld by any of the Borrowers and paid to or deposited to or to the credit of the United States of America pursuant to the provisions of the Internal Revenue Code of 1986, as amended, in respect of any and all wages and salaries paid to employees of the Borrowers; or (f) Any final judgment on the merits for the payment of money in an amount in excess of $500,000 shall be outstanding against any of the Borrowers and such judgment shall remain unstayed and in effect and unpaid for more than thirty (30) days; or (g) Any Reportable Event described in Section 7.15 hereof which the Banks determine in good faith might consti- tute grounds for the termination of a Plan therein described or for the appointment by the appropriate United States District Court of a trustee to administer any such Plan shall have occurred and be continuing thirty (30) days after written notice to such effect shall have been given to any of the Borrowers by the Agent or the Banks, or any such Plan shall be terminated, or a trustee shall be appointed by a United States District Court to administer any such Plan or the Pension Benefit Guaranty Corporation shall institute proceedings to terminate any such Plan or to appoint a trustee to administer any such Plan; or (h) Any default or event of default occurs and is continuing beyond any cure period with respect thereto under any of the other Loan Documents. 8.2 Remedies. Upon the occurrence of any Event of Default referred to in Section 8.1(e), the Line Commitment (to the extent on or prior to the Commitment Termination Date) shall immediately and automatically terminate and the Notes (whether before or after the Conversion Date) and all other Indebtedness shall be immediate- ly due and payable, without notice of any kind. Upon the occur- rence of any other Event of Default, and without prejudice to any right or remedy of the Banks under this Agreement or the Loan Documents or under applicable Law or under any other instrument or document delivered in connection herewith, the Agent or the Banks may (i) declare the Commitments terminated or (ii) declare both of the Commitments terminated and declare the Notes and the other Indebtedness, or any part thereof, to be forthwith due and payable, 38 whereupon the Notes and the other Indebtedness, or such portion as is designated by the Banks shall forthwith become due and payable, without presentment, demand, notice or protest of any kind, all of which are hereby expressly waived by the Borrowers. No delay or omission on the part of the Agent or the Banks in exercising any power or right hereunder or under the Notes, the Loan Documents or under applicable law shall impair such right or power or be construed to be a waiver of any default or any acquiescence therein, nor shall any single or partial exercise by the Agent or the Banks of any such power or right preclude other or further exercise thereof or the exercise of any other such power or right by the Agent or the Banks. In the event that all or part of the Indebtedness becomes or is declared to be forthwith due and payable as herein provided, the Banks shall have the right to set off the amount of all the Indebtedness of the Borrowers owing to the Banks against, and shall have a lien upon and security interest in, all property of the Borrowers in the Banks' possession at or subsequent to such default, regardless of the capacity in which the Banks possess such property, including but not limited to any balance or share of any deposit, demand, collection or agency account, subject to Section 9.3 hereof. At any time after the occurrence of any Event of Default, the Banks may, at their option, cause an audit of any and/or all of the books, records and documents of the Borrow- ers, with the exception of the portion thereof covered by an attorney-client privilege or constituting attorney work product, to be made by auditors satisfactory to the Banks. The Banks also shall have, and may exercise, each and every right and remedy granted to them for default under the terms of the other Loan Documents. ARTICLE IX MISCELLANEOUS 9.1 Notices. Unless otherwise provided herein, all notices, requests, consents and demands shall be in writing and shall be either hand-delivered (by courier or otherwise), sent by fax or telecopy to the respective fax or telecopy number specified below or mailed by certified mail, postage prepaid, to the respective addresses specified below, or, as to any party, to such other address as may be designated by it in written notice to the other parties: If to the Borrowers, to: 1000 Galleria Tower 1 7130 South Lewis Tulsa, Oklahoma 74172 FAX NO: (918) 493-7711 39 If to BOK, to: Bank of Oklahoma, National Association P. O. Box 2300 101 East 2nd Street Tulsa, Oklahoma 74192 Attention: Energy Department FAX NO: (918) 588-6880 If to BANK IV, to: BANK IV Oklahoma, N.A. P. O. Box 2360 515 South Boulder Tulsa, Oklahoma 74101-2360 Attention: Energy Department FAX NO: (918) 591-8487 If to Bank of Boston, to: The First National Bank of Boston P.O. Box 2016 100 Federal Street Energy & Utility Division 01-08-02 Boston, Massachusetts 02110 Attention: Ms. Carol Holley FAX NO: (617) 434-3652 If to ANB, to: American National Bank and Trust Company of Shawnee P.O. Box 1089 Shawnee, Oklahoma 74801-1089 Attention: Tony M. McMurry, Executive Vice President FAX NO: (405) 275-9240 If to the Agent, to: Bank of Oklahoma, National Association P. O. Box 2300 101 East 2nd Street Tulsa, Oklahoma 74192 Attention: Energy Department FAX NO: (918) 588-6880 All notices, requests, consents and demands hereunder will be effective when hand-delivered to the applicable notice addresses of any party hereto or when sent by fax or telecopy to the applicable fax or telecopy numbers of any party hereto or when mailed by certified mail, postage prepaid, addressed as aforesaid by any party hereto. 40 9.2 Place of Payment. All sums payable hereunder shall be paid in immediately available funds to the Agent, at its principal banking offices at Bank of Oklahoma Tower, 101 East Second Street, One Williams Center in Tulsa, Oklahoma, or at such other place as the Agent shall notify the Borrowers in writing. If any interest, principal or other payment falls due on a date other than a Business Day, then (unless otherwise provided herein) such due date shall be extended to the next succeeding Business Day, and such extension of time will in such case be included in computing interest, if any, in connection with such payment. 9.3 Setoff. Any indebtedness owing from any of the Banks to any of the Borrowers, including, without limitation, any general or special deposit account (excluding, however, the following accounts at BOK; Account Nos. 1-01174868, 1-022-5426-5, 1-026-5743-7, 1-035-7018-4, 1- 035-9028-1, 1-038-4862-7, 1-038-4077-3, 2-042-1333-2, 2-043-5134-9, 2-060-0786- 1, 2-078-9622-0, 2-079-1080-6, 2-079-1154-3, 2-079-1087-2, 2-079-2793-3, 2-079- 2310-4, 2-079-2353-3, 2-079-2860-4, 2-079-2861-5, 2-079-2862-6, 2-079-2864-8, 2- 079-3738-2 and 2-083-0274-7), may be set off or otherwise applied by the Banks under a general lien and security interest covering such indebtedness which is hereby granted on any indebtedness or liability of Borrowers under any Loan Document to the Banks, at any time and from and after the occurrence of an Event of Default, either before or after Maturity, and without demand or notice to anyone. It is understood any of the Banks may sell participations in the Notes to an affiliate of such Bank, and Borrowers agree that any such participant shall have the right of setoff or other application under the general lien as herein granted to the Banks; provided, however, it is specifically acknowledged by the Banks that any other participation shall require the written prior approval of Unit on behalf of each of the Borrowers. 9.4 Survival of Agreements. All covenants, agreements, representations and warranties made herein shall survive the execution and the delivery of Loan Documents. All statements contained in any certificate or other instrument executed and delivered by the Borrowers hereunder shall be deemed to constitute representations and warranties by the Borrowers. 9.5 Parties in Interest. All covenants, agreements and obligations contained in this Agreement shall bind and inure to the benefit of the respective successors and assigns of the parties hereto, except that the Borrowers may not assign their rights or obligations hereunder without the prior written consent of the Banks. Each of the Banks may sell participations in its interest hereunder and under its Note without the prior written consent of the Borrowers or sell, assign or transfer such interests with such prior consent, provided that no such consent shall be required in the case of a sale, transfer or assignment to any affiliate of any of the Banks. Notwithstanding anything to the contrary provided herein, each Bank may, at any time, without the consent of the Borrowers, assign all or any portion of its rights under this 41 Agreement and its Note to a Federal Reserve Bank, provided that no such assignment shall release any Bank from its obligations hereunder. 9.6 Governing Law. This Agreement, the Notes and the Security Instruments shall be deemed to have been made or incurred under the Laws of the State of Oklahoma and shall be construed and enforced in accordance with and governed by the Laws of Oklahoma. 9.7 SUBMISSION TO JURISDICTION. THE BORROWERS HEREBY CONSENT TO THE JURISDICTION OF ANY OF THE STATE AND FEDERAL COURTS LOCATED WITHIN TULSA COUNTY, OKLAHOMA AND WAIVE ANY OBJECTION WHICH BORROWERS MAY HAVE BASED ON IMPROPER VENUE OR FORUM NON CONVENIENS TO THE CONDUCT OF ANY PROCEEDING IN ANY SUCH COURT. 9.8 Maximum Interest Rate. Regardless of any provision herein, the Agent and the Banks shall never be entitled to receive, collect or apply, as interest on the Indebtedness any amount in excess of the maximum rate of interest permitted to be charged by the Banks by applicable Law, and, in the event the Agent or the Banks shall ever receive, collect or apply, as interest, any such excess, such amount which would be excessive interest shall be applied to other Indebtedness and then to the reduction of principal; and, if the other Indebtedness and principal are paid in full, then any remaining excess shall forthwith be paid to the Borrowers. 9.9 No Waiver; Cumulative Remedies. No failure to exercise, and no delay in exercising, on the part of the Agent or any of the Banks, any right, power or privilege hereunder or under any other Loan Document or applicable Law shall preclude any other or further exercise thereof or the exercise of any other right, power or privilege of the Agent or any of the Banks. The rights and remedies herein provided are cumulative and not exclusive of any other rights or remedies provided by any other instrument or by law. No amendment, modification or waiver of any provision of this Agreement or any other Loan Document shall be effective unless the same shall be in writing and signed by the Agent and the Banks. No notice to or demand on the Borrowers in any case shall entitle the Borrowers to any other or further notice or demand in similar or other circumstances. 9.10 Costs. The Borrowers agree to pay to the Agent for the benefit of the Banks on demand all recording fees and filing costs and all reasonable attorneys fees and legal expenses incurred or accrued by the Banks in connection with the preparation, negotia- tion, closing, administration of the Loan Documents and the filing and recording of the Security Instruments or any amendment, waiver, consent or modification to and of the Loan Documents. In any action to enforce or construe the provisions of this Agreement or any of the Loan Documents, the prevailing party shall be entitled to recover its reasonable attorneys' fees and all costs and expenses related thereto. 42 9.11 Change of Agent. Upon receipt of notice of the name and address of a new Agent, duly executed by the Banks, the Borrowers shall thereafter direct to the new Agent all reports, payments and other information required to be delivered to the Agent pursuant to the terms of this Agreement and all other Loan Documents. 9.12 Headings. The article and section headings of this Agreement are for convenience of reference only and shall not constitute a part of the text hereof nor alter or otherwise affect the meaning hereof. 9.13 Severability. The unenforceability or invalidity as determined by a Tribunal of competent jurisdiction, of any provision or provisions of this Agreement shall not render un- enforceable or invalid any other provision or provisions hereof. 9.14 Counterparts and Execution. This Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument. Notwithstanding the single execution of this Agreement by the President of each of the Borrowers, each of the Borrowers is jointly and severally bound by the terms of this Agreement. 43 IN WITNESS WHEREOF, the Borrowers have caused this Agreement to be executed and delivered to the Banks in Tulsa, Oklahoma as of the day and year first above written by the undersigned duly authorized corporate officer thereof. "Borrowers" UNIT CORPORATION, a Delaware corporation UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation UNIT PETROLEUM COMPANY, an Oklahoma corporation UNIT DRILLING COMPANY, an Oklahoma corporation PETROLEUM SUPPLY COMPANY, an Oklahoma corporation ROUNDUP RESOURCES, INC., a Delaware corporation By_________________________________ John G. Nikkel, President of UNIT CORPORATION, UNIT DRILLING AND EXPLORATION COMPANY, MOUNTAIN FRONT PIPELINE COMPANY, INC., UNIT PETROLEUM COMPANY, UNIT DRILLING COMPANY, PETROLEUM SUPPLY COMPANY, ROUNDUP RESOURCES, INC. 44 "Banks" BANK OF OKLAHOMA, NATIONAL ASSOCIATION By_____________________________ Pam Schloeder, Vice President P. O. Box 2300 Tulsa, Oklahoma 74192 "Agent" BANK OF OKLAHOMA, NATIONAL ASSOCIATION By____________________________ Pam Schloeder, Vice President P. O. Box 2300 Tulsa, Oklahoma 74192 45 THE FIRST NATIONAL BANK OF BOSTON By___________________________________ ________________, _______________ P.O. Box 2016 100 Federal Street Energy & Utility Division 01-08-02 Boston, Massachusetts 02110 46 BANK IV OKLAHOMA, N.A. By______________________ Glenn A. Elrod Senior Vice President P. O. Box 2360 Tulsa, Oklahoma 74101-2360 47 AMERICAN NATIONAL BANK AND TRUST COMPANY OF SHAWNEE By_______________________ Tony M. McMurry Executive Vice President P. O. Box 1089 Shawnee, Oklahoma 74801-1089 48 EXHIBIT "A-1" PROMISSORY NOTE $25,000,000 August 3, 1995 Tulsa, Oklahoma FOR VALUE RECEIVED, the undersigned, UNIT CORPORATION, a Delaware corporation, UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation, MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation, UNIT DRILLING COMPANY, an Oklahoma corpora- tion, UNIT PETROLEUM COMPANY (formerly Sunshine Development Corpor- ation), an Oklahoma corporation, PETROLEUM SUPPLY COMPANY, an Okla- homa corporation, and ROUNDUP RESOURCES, INC., a Delaware corpora- tion, (individually and collectively the "Borrowers"), jointly and severally promise to pay to the order of BANK OF OKLAHOMA, NATIONAL ASSOCIATION ("BOK"), with interest, the principal sum of TWENTY FIVE MILLION and no/100ths DOLLARS ($25,000,000) or, if less, the aggregate principal amount of all advances made by BOK to Borrowers pursuant to the Loan Agreement dated as of August 3, 1995 among Borrowers, BOK, BANK IV Oklahoma, N.A., The First National Bank of Boston and American National Bank and Trust Company of Shawnee (collectively the "Banks"), with BOK as Agent (the "Loan Agree- ment"), which are outstanding as of August 31, 1997 (the "Commit- ment Termination Date"). Such outstanding principal shall be payable in forty-eight (48) consecutive monthly installments commencing September 1, 1997, and continuing on the first (1st) day of each month thereafter through August 1, 2001 ("Maturity"). Each of the first forty-seven (47) of such principal installments shall be in the amount derived by dividing the principal amount hereof outstanding on the Commitment Termination Date by forty-eight (48). The forty-eighth (48th) and final installment shall be in the amount of the remaining principal balance of this Note at Maturity plus all accrued but unpaid interest hereon. Except as hereinafter provided in connection with a default, interest shall accrue on the outstanding principal balance hereof and on any past due interest through Maturity at the rate or rates per annum determined pursuant to the Loan Agreement, payable as provided therein, and shall be calculated as provided in the Loan Agreement. The rate of interest payable upon the indebtedness evidenced by this Note shall not at any time exceed the maximum rate of interest permitted under the laws of the State of Oklahoma or federal laws to the extent they apply for loans of the type and character evidenced by this Note. All payments under this Note shall be made in legal tender of the United States of America or in other immediately available funds at the offices of the Agent at Bank of Oklahoma Tower, 7 East 2nd Street, Tulsa, Oklahoma 74172, and no credit shall be given for any payment received by check, draft or other instrument or item until such time as the Agent or the holder hereof shall have received credit therefor from the Agent's or the holder's collect- ing agent or, in the event no collecting agent is used, from the bank or other financial institution upon which said check, draft or other instrument or item is drawn. If any payment is due upon a Saturday or Sunday or upon any other day on which state or national banks in the State of Oklahoma are closed for business by virtue of a legal holiday for such banks, such payment shall be due and payable on the next succeeding Business Day, and interest shall accrue to such day. Prior to the Commitment Termination Date, the Borrowers may borrow, repay and reborrow hereunder at any time and from time to time as provided in the Loan Agreement. From and after the Commitment Termination Date, the Borrowers may prepay this Note in whole or in part, subject to the prepayment limitations contained in the Loan Agreement; provided, however, that any partial prepayment shall be applied first to accrued interest, then to unpaid principal installments in the inverse order of maturity. From time to time the Borrowers and the Banks may agree to extend the maturity date of this Note or to renew this Note, in whole or in part, or a new note of different form may be substitut- ed for this Note and/or the rate of interest may be changed, or changes may be made in consideration of loan extensions, and the holder, from time to time, may waive or surrender, either in whole or in part, any rights, guarantees, security interests, or liens given for the benefit of the holder in connection with the payment and the securing the payment of this Note; but no such occurrences shall in any manner affect, limit, modify or otherwise impair any rights, guarantees or security of the holder not specifically waived, released or surrendered in writing, nor shall the Borrowers or any guarantor, endorser or any other person who is or might be liable hereon, either primarily or contingently, be released from such liability by reason of the occurrence of any such event. The holder hereof, from time to time, shall have the unlimited right to release any person who might be liable hereon; and such release shall not affect or discharge the liability of any other person who is or might be liable hereon. If any payment required by this Note to be made is not made within ten (10) Business Days after the same shall become due and payable, or if any default occurs under the Loan Agreement, the Security Agreement or under the provisions of any mortgage, deed of trust, security agreement, assignment, pledge or other document or agreement which provides security for the indebtedness evidenced by this Note, the holder hereof may, at its option, without notice or demand, declare this Note in default and all indebtedness due and owing hereunder immediately due and payable. In the event of a default the entire unpaid balance shall be immediately due and payable, together with any past due interest at the rate of five percentage points (5%) per annum above the Applicable Prime Rate ("Default Rate"). The Borrowers and all endorsers, guarantors and 2 sureties hereby severally waive protest, presentment, demand, and notice of protest and nonpayment in case this Note or any payment due hereunder is not paid when due; and they agree to any renewal of this Note or to any extension, acceleration or postponement of the time of payment, or any other indulgence, to any substituting, exchange or release of collateral and to the release of any party or person primarily or contingently liable hereon without prejudice to the holder and without notice to the Borrowers or any endorser, guarantor or surety. In the event of any controversy, claim or dispute between the parties affecting or relating to the subject matter or performance of this Note, the prevailing party shall be entitled to recover from the non-prevailing party all of its reasonable costs, expenses, including reasonable attorneys' and accountants' fees. In the event the Agent or BOK is the prevailing party, the Borrowers, and any guarantor, endorser, surety or any other person who is or may become liable hereon, will, on demand, pay all such costs and expenses. Upon the occurrence of any default hereunder, BOK shall have the right, immediately and without further action by it, to set off against this Note all money owed by BOK in any capacity (except for balances in the following accounts with BOK: Account Nos. 1-01174868, 1-022-5426-5, 1-026-5743-7, 1-035-7018-4, 1-035-9028-1, 1-038-4862-7, 1-038-4077-3, 2-042-1333-2, 2-043-5134-9, 2-060-0786-1, 2-078-9622-0, 2-079-1080-6, 2-079-1154-3, 2-079-1087-2, 2-079-2793-3, 2-079-2310-4, 2-079-2353-3, 2-079-2860-4, 2-079-2861-5, 2-079-2862-6, 2-079-2864-8, 2-079-3738-2 and 2-083-027 4-7), to each or any of the Borrowers, guarantor, endorser or any other person who is or might be liable for payment hereof, whether or not due, and also to set off against all other liabilities of each of the Borrowers to BOK all money owed by BOK in any capacity to each or any of the Borrowers; and BOK shall be deemed to have exercised such right of setoff and to have made a charge against such money immediately upon the occurrence of such default even though such charge is made or entered into the books of BOK subsequently thereto. This Note is issued pursuant to and subject to the terms of the Loan Agreement and is secured by the Collateral described in the Loan Agreement, which provides, among other things, for prepayment of this Note upon the occurrence of certain events and for limitations on advances which may be made hereunder. This Note is a renewal, extension, substitution and replacement in that certain promissory note dated June 1, 1995, payable by Borrowers to the order of BOK in the original principal amount of $25,000,000. Capitalized terms used and not otherwise defined herein shall have the meanings assigned to them in the Loan Agreement. This Note shall be governed by and construed in accordance with the laws of the State of Oklahoma. Borrowers agree that all suits or proceedings arising from or related to this Note or the Loan Agreement may be litigated in courts, state or federal, 3 sitting in the State of Oklahoma. In furtherance of this provi- sion, Borrowers hereby waive any objection to such venue. Notwithstanding the single execution of this Note by the President of each of the Borrowers, each of the Borrowers is jointly and severally bound by the terms of this Note. "Borrowers" UNIT CORPORATION, a Delaware corporation UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation UNIT PETROLEUM COMPANY, an Oklahoma corporation UNIT DRILLING COMPANY, an Oklahoma corporation PETROLEUM SUPPLY COMPANY, an Oklahoma corporation ROUNDUP RESOURCES, INC., a Delaware corporation By___________________________________ John G. Nikkel, President of UNIT CORPORATION, UNIT DRILLING AND EXPLORATION COMPANY, MOUNTAIN FRONT PIPELINE COMPANY, INC., UNIT PETRO- LEUM COMPANY, UNIT DRILLING COMPA- NY, PETROLEUM SUPPLY COMPANY, ROUNDUP RESOURCES, INC. Due: August 31, 1997 (subject to conversion to Term Loan payout on August 31, 1997 per Loan Agreement) 4 EXHIBIT "A-2" PROMISSORY NOTE $23,500,000 August 3, 1995 Tulsa, Oklahoma FOR VALUE RECEIVED, the undersigned, UNIT CORPORATION, a Delaware corporation, UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation, MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation, UNIT DRILLING COMPANY, an Oklahoma corpora- tion, UNIT PETROLEUM COMPANY (formerly Sunshine Development Corpor- ation), an Oklahoma corporation, PETROLEUM SUPPLY COMPANY, an Okla- homa corporation, and ROUNDUP RESOURCES, INC., a Delaware corpora- tion, (individually and collectively the "Borrowers"), jointly and severally promise to pay to the order of THE FIRST NATIONAL BANK OF BOSTON ("Bank of Boston"), with interest, the principal sum of TWENTY THREE MILLION FIVE HUNDRED THOUSAND and no/100ths DOLLARS ($23,500,000) or, if less, the aggregate principal amount of all advances made by Bank of Boston to Borrowers pursuant to the Loan Agreement dated as of August 3, 1995 among Borrowers, Bank of Boston, Bank of Oklahoma, National Association ("BOK"), BANK IV Oklahoma, N.A. and American National Bank and Trust Company of Shawnee (collectively the "Banks"), with BOK as Agent (the "Loan Agreement"), which are outstanding as of August 31, 1997 (the "Commitment Termination Date"). Such outstanding principal shall be payable in forty-eight (48) consecutive monthly installments commencing September 1, 1997, and continuing on the first (1st) day of each month thereafter through August 1, 2001 ("Maturity"). Each of the first forty-seven (47) of such principal installments shall be in the amount derived by dividing the principal amount hereof outstanding on the Commitment Termination Date by forty-eight (48). The forty-eighth (48th) and final installment shall be in the amount of the remaining principal balance of this Note at Maturity plus all accrued but unpaid interest hereon. Except as hereinafter provided in connection with a default, interest shall accrue on the outstanding principal balance hereof and on any past due interest through Maturity at the rate or rates per annum determined pursuant to the Loan Agreement, payable as provided therein, and shall be calculated as provided in the Loan Agreement. The rate of interest payable upon the indebtedness evidenced by this Note shall not at any time exceed the maximum rate of interest permitted under the laws of the State of Oklahoma or federal laws to the extent they apply for loans of the type and character evidenced by this Note. All payments under this Note shall be made in legal tender of the United States of America or in other immediately available funds at the offices of the Agent at Bank of Oklahoma Tower, 7 East 2nd Street, Tulsa, Oklahoma 74172, and no credit shall be given for any payment received by check, draft or other instrument or item until such time as the Agent or the holder hereof shall have received credit therefor from the Agent's or the holder's collect- ing agent or, in the event no collecting agent is used, from the bank or other financial institution upon which said check, draft or other instrument or item is drawn. If any payment is due upon a Saturday or Sunday or upon any other day on which state or national banks in the State of Oklahoma are closed for business by virtue of a legal holiday for such banks, such payment shall be due and payable on the next succeeding Business Day, and interest shall accrue to such day. Prior to the Commitment Termination Date, the Borrowers may borrow, repay and reborrow hereunder at any time and from time to time as provided in the Loan Agreement. From and after the Commitment Termination Date, the Borrowers may prepay this Note in whole or in part, subject to the prepayment limitations contained in the Loan Agreement; provided, however, that any partial prepayment shall be applied first to accrued interest, then to unpaid principal installments in the inverse order of maturity. From time to time the Borrowers and the Banks may agree to extend the maturity date of this Note or to renew this Note, in whole or in part, or a new note of different form may be substitut- ed for this Note and/or the rate of interest may be changed, or changes may be made in consideration of loan extensions, and the holder, from time to time, may waive or surrender, either in whole or in part, any rights, guarantees, security interests, or liens given for the benefit of the holder in connection with the payment and the securing the payment of this Note; but no such occurrences shall in any manner affect, limit, modify or otherwise impair any rights, guarantees or security of the holder not specifically waived, released or surrendered in writing, nor shall the Borrowers or any guarantor, endorser or any other person who is or might be liable hereon, either primarily or contingently, be released from such liability by reason of the occurrence of any such event. The holder hereof, from time to time, shall have the unlimited right to release any person who might be liable hereon; and such release shall not affect or discharge the liability of any other person who is or might be liable hereon. If any payment required by this Note to be made is not made within ten (10) Business Days after the same shall become due and payable, or if any default occurs under the Loan Agreement, the Security Agreement or under the provisions of any mortgage, deed of trust, security agreement, assignment, pledge or other document or agreement which provides security for the indebtedness evidenced by this Note, the holder hereof may, at its option, without notice or demand, declare this Note in default and all indebtedness due and owing hereunder immediately due and payable. In the event of a default the entire unpaid balance shall be immediately due and payable, together with any past due interest at the rate of five percentage points (5%) per annum above the Applicable Prime Rate 2 ("Default Rate"). The Borrowers and all endorsers, guarantors and sureties hereby severally waive protest, presentment, demand, and notice of protest and nonpayment in case this Note or any payment due hereunder is not paid when due; and they agree to any renewal of this Note or to any extension, acceleration or postponement of the time of payment, or any other indulgence, to any substituting, exchange or release of collateral and to the release of any party or person primarily or contingently liable hereon without prejudice to the holder and without notice to the Borrowers or any endorser, guarantor or surety. In the event of any controversy, claim or dispute between the parties affecting or relating to the subject matter or performance of this Note, the prevailing party shall be entitled to recover from the non-prevailing party all of its reasonable costs, expenses, including reasonable attorneys' and accountants' fees. In the event the Agent or Bank of Boston is the prevailing party, the Borrowers, and any guarantor, endorser, surety or any other person who is or may become liable hereon, will, on demand, pay all such costs and expenses. Upon the occurrence of any default hereunder, Bank of Boston shall have the right, immediately and without further action by it, to set off against this Note all money owed by Bank of Boston in any capacity, to each or any of the Borrowers, guarantor, endorser or any other person who is or might be liable for payment hereof, whether or not due, and also to set off against all other liabili- ties of each of the Borrowers to Bank of Boston all money owed by Bank of Boston in any capacity to each or any of the Borrowers; and Bank of Boston shall be deemed to have exercised such right of setoff and to have made a charge against such money immediately upon the occurrence of such default even though such charge is made or entered into the books of Bank of Boston subsequently thereto. This Note is issued pursuant to and subject to the terms of the Loan Agreement and is secured by the Collateral described in the Loan Agreement, which provides, among other things, for prepayment of this Note upon the occurrence of certain events and for limitations on advances which may be made hereunder. Capital- ized terms used and not otherwise defined herein shall have the meanings assigned to them in the Loan Agreement. This Note shall be governed by and construed in accordance with the laws of the State of Oklahoma. Borrowers agree that all suits or proceedings arising from or related to this Note or the Loan Agreement may be litigated in courts, state or federal, sitting in the State of Oklahoma. In furtherance of this provi- sion, Borrowers hereby waive any objection to such venue. 3 Notwithstanding the single execution of this Note by the President of each of the Borrowers, each of the Borrowers is jointly and severally bound by the terms of this Note. "Borrowers" UNIT CORPORATION, a Delaware corporation UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation UNIT PETROLEUM COMPANY, an Oklahoma corporation UNIT DRILLING COMPANY, an Oklahoma corporation PETROLEUM SUPPLY COMPANY, an Oklahoma corporation ROUNDUP RESOURCES, INC., a Delaware corporation By___________________________________ John G. Nikkel, President of UNIT CORPORATION, UNIT DRILLING AND EXPLORATION COMPANY, MOUNTAIN FRONT PIPELINE COMPANY, INC., UNIT PETRO- LEUM COMPANY, UNIT DRILLING COMPA- NY, PETROLEUM SUPPLY COMPANY, ROUNDUP RESOURCES, INC. Due: August 31, 1997 (subject to conversion to Term Loan payout on August 31, 1997 per Loan Agreement) 4 EXHIBIT "A-3" PROMISSORY NOTE $25,000,000 August 3, 1995 Tulsa, Oklahoma FOR VALUE RECEIVED, the undersigned, UNIT CORPORATION, a Delaware corporation, UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation, MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation, UNIT DRILLING COMPANY, an Oklahoma corpora- tion, UNIT PETROLEUM COMPANY (formerly Sunshine Development Corpor- ation), an Oklahoma corporation, PETROLEUM SUPPLY COMPANY, an Okla- homa corporation, and ROUNDUP RESOURCES, INC., a Delaware corpora- tion, (individually and collectively the "Borrowers"), jointly and severally promise to pay to the order of BANK IV OKLAHOMA, N.A. ("BANK IV"), with interest, the principal sum of TWENTY FIVE MILLION and no/100ths DOLLARS ($25,000,000) or, if less, the aggregate principal amount of all advances made by BANK IV to Borrowers pursuant to the Loan Agreement dated as of August 3, 1995 among Borrowers, BANK IV, Bank of Oklahoma, National Association ("BOK"), The First National Bank of Boston and American National Bank and Trust Company of Shawnee (collectively the "Banks"), with BOK as Agent (the "Loan Agreement"), which are outstanding as of August 31, 1997 (the "Commitment Termination Date"). Such out- standing principal shall be payable in forty-eight (48) consecutive monthly installments commencing September 1, 1997, and continuing on the first (1st) day of each month thereafter through August 1, 2001 ("Maturity"). Each of the first forty-seven (47) of such principal installments shall be in the amount derived by dividing the principal amount hereof outstanding on the Commitment Termina- tion Date by forty-eight (48). The forty-eighth (48th) and final installment shall be in the amount of the remaining principal balance of this Note at Maturity plus all accrued but unpaid interest hereon. Except as hereinafter provided in connection with a default, interest shall accrue on the outstanding principal balance hereof and on any past due interest through Maturity at the rate or rates per annum determined pursuant to the Loan Agreement, payable as provided therein, and shall be calculated as provided in the Loan Agreement. The rate of interest payable upon the indebtedness evidenced by this Note shall not at any time exceed the maximum rate of interest permitted under the laws of the State of Oklahoma or federal laws to the extent they apply for loans of the type and character evidenced by this Note. All payments under this Note shall be made in legal tender of the United States of America or in other immediately available funds at the offices of the Agent at Bank of Oklahoma Tower, 7 East 2nd Street, Tulsa, Oklahoma 74172, and no credit shall be given for any payment received by check, draft or other instrument or item until such time as the Agent or the holder hereof shall have received credit therefor from the Agent's or the holder's collect- ing agent or, in the event no collecting agent is used, from the bank or other financial institution upon which said check, draft or other instrument or item is drawn. If any payment is due upon a Saturday or Sunday or upon any other day on which state or national banks in the State of Oklahoma are closed for business by virtue of a legal holiday for such banks, such payment shall be due and payable on the next succeeding Business Day, and interest shall accrue to such day. Prior to the Commitment Termination Date, the Borrowers may borrow, repay and reborrow hereunder at any time and from time to time as provided in the Loan Agreement. From and after the Commitment Termination Date, the Borrowers may prepay this Note in whole or in part, subject to the prepayment limitations contained in the Loan Agreement; provided, however, that any partial prepayment shall be applied first to accrued interest, then to unpaid principal installments in the inverse order of maturity. From time to time the Borrowers and the Banks may agree to extend the maturity date of this Note or to renew this Note, in whole or in part, or a new note of different form may be substitut- ed for this Note and/or the rate of interest may be changed, or changes may be made in consideration of loan extensions, and the holder, from time to time, may waive or surrender, either in whole or in part, any rights, guarantees, security interests, or liens given for the benefit of the holder in connection with the payment and the securing the payment of this Note; but no such occurrences shall in any manner affect, limit, modify or otherwise impair any rights, guarantees or security of the holder not specifically waived, released or surrendered in writing, nor shall the Borrowers or any guarantor, endorser or any other person who is or might be liable hereon, either primarily or contingently, be released from such liability by reason of the occurrence of any such event. The holder hereof, from time to time, shall have the unlimited right to release any person who might be liable hereon; and such release shall not affect or discharge the liability of any other person who is or might be liable hereon. If any payment required by this Note to be made is not made within ten (10) Business Days after the same shall become due and payable, or if any default occurs under the Loan Agreement, the Security Agreement or under the provisions of any mortgage, deed of trust, security agreement, assignment, pledge or other document or agreement which provides security for the indebtedness evidenced by this Note, the holder hereof may, at its option, without notice or demand, declare this Note in default and all indebtedness due and owing hereunder immediately due and payable. In the event of a default the entire unpaid balance shall be immediately due and payable, together with any past due interest at the rate of five percentage points (5%) per annum above the Applicable Prime Rate ("Default Rate"). The Borrowers and all endorsers, guarantors and 2 sureties hereby severally waive protest, presentment, demand, and notice of protest and nonpayment in case this Note or any payment due hereunder is not paid when due; and they agree to any renewal of this Note or to any extension, acceleration or postponement of the time of payment, or any other indulgence, to any substituting, exchange or release of collateral and to the release of any party or person primarily or contingently liable hereon without prejudice to the holder and without notice to the Borrowers or any endorser, guarantor or surety. In the event of any controversy, claim or dispute between the parties affecting or relating to the subject matter or performance of this Note, the prevailing party shall be entitled to recover from the non-prevailing party all of its reasonable costs, expenses, including reasonable attorneys' and accountants' fees. In the event the Agent or BANK IV is the prevailing party, the Borrowers, and any guarantor, endorser, surety or any other person who is or may become liable hereon, will, on demand, pay all such costs and expenses. Upon the occurrence of any default hereunder, BANK IV shall have the right, immediately and without further action by it, to set off against this Note all money owed by BANK IV in any capacity, to each or any of the Borrowers, guarantor, endorser or any other person who is or might be liable for payment hereof, whether or not due, and also to set off against all other liabili- ties of each of the Borrowers to BANK IV all money owed by BANK IV in any capacity to each or any of the Borrowers; and BANK IV shall be deemed to have exercised such right of setoff and to have made a charge against such money immediately upon the occurrence of such default even though such charge is made or entered into the books of BANK IV subsequently thereto. This Note is issued pursuant to and subject to the terms of the Loan Agreement and is secured by the Collateral described in the Loan Agreement, which provides, among other things, for prepayment of this Note upon the occurrence of certain events and for limitations on advances which may be made hereunder. Capital- ized terms used and not otherwise defined herein shall have the meanings assigned to them in the Loan Agreement. This Note shall be governed by and construed in accordance with the laws of the State of Oklahoma. Borrowers agree that all suits or proceedings arising from or related to this Note or the Loan Agreement may be litigated in courts, state or federal, sitting in the State of Oklahoma. In furtherance of this provi- sion, Borrowers hereby waive any objection to such venue. 3 Notwithstanding the single execution of this Note by the President of each of the Borrowers, each of the Borrowers is jointly and severally bound by the terms of this Note. "Borrowers" UNIT CORPORATION, a Delaware corporation UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation UNIT PETROLEUM COMPANY, an Oklahoma corporation UNIT DRILLING COMPANY, an Oklahoma corporation PETROLEUM SUPPLY COMPANY, an Oklahoma corporation ROUNDUP RESOURCES, INC., a Delaware corporation By___________________________________ John G. Nikkel, President of UNIT CORPORATION, UNIT DRILLING AND EXPLORATION COMPANY, MOUNTAIN FRONT PIPELINE COMPANY, INC., UNIT PETRO- LEUM COMPANY, UNIT DRILLING COMPA- NY, PETROLEUM SUPPLY COMPANY, ROUNDUP RESOURCES, INC. Due: August 31, 1997 (subject to conversion to Term Loan payout on August 31, 1997 per Loan Agreement) 4 EXHIBIT "A-4" PROMISSORY NOTE $1,500,000 August 3, 1995 Tulsa, Oklahoma FOR VALUE RECEIVED, the undersigned, UNIT CORPORATION, a Delaware corporation, UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation, MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation, UNIT DRILLING COMPANY, an Oklahoma corpora- tion, UNIT PETROLEUM COMPANY (formerly Sunshine Development Corpor- ation), an Oklahoma corporation, PETROLEUM SUPPLY COMPANY, an Okla- homa corporation, and ROUNDUP RESOURCES, INC., a Delaware corpora- tion, (individually and collectively the "Borrowers"), jointly and severally promise to pay to the order of AMERICAN NATIONAL BANK AND TRUST COMPANY OF SHAWNEE ("ANB"), with interest, the principal sum of ONE MILLION FIVE HUNDRED THOUSAND and no/100ths DOLLARS ($1,500,000) or, if less, the aggregate principal amount of all advances made by ANB to Borrowers pursuant to the Loan Agreement dated as of August 3, 1995 among Borrowers, ANB, Bank of Oklahoma, National Association ("BOK") and The First National Bank of Boston, BANK IV Oklahoma, N.A. (collectively the "Banks"), with BOK as Agent (the "Loan Agreement"), which are outstanding as of August 31, 1997 (the "Commitment Termination Date"). Such outstanding principal shall be payable in forty-eight (48) consecutive monthly installments commencing September 1, 1997, and continuing on the first (1st) day of each month thereafter through August 1, 2001 ("Maturity"). Each of the first forty-seven (47) of such principal installments shall be in the amount derived by dividing the principal amount hereof outstanding on the Commitment Termination Date by forty-eight (48). The forty-eighth (48th) and final installment shall be in the amount of the remaining principal balance of this Note at Maturity plus all accrued but unpaid interest hereon. Except as hereinafter provided in connection with a default, interest shall accrue on the outstanding principal balance hereof and on any past due interest through Maturity at the rate or rates per annum determined pursuant to the Loan Agreement, payable as provided therein, and shall be calculated as provided in the Loan Agreement. The rate of interest payable upon the indebtedness evidenced by this Note shall not at any time exceed the maximum rate of interest permitted under the laws of the State of Oklahoma or federal laws to the extent they apply for loans of the type and character evidenced by this Note. All payments under this Note shall be made in legal tender of the United States of America or in other immediately available funds at the offices of the Agent at Bank of Oklahoma Tower, 7 East 2nd Street, Tulsa, Oklahoma 74172, and no credit shall be given for any payment received by check, draft or other instrument or item until such time as the Agent or the holder hereof shall have received credit therefor from the Agent's or the holder's collect- ing agent or, in the event no collecting agent is used, from the bank or other financial institution upon which said check, draft or other instrument or item is drawn. If any payment is due upon a Saturday or Sunday or upon any other day on which state or national banks in the State of Oklahoma are closed for business by virtue of a legal holiday for such banks, such payment shall be due and payable on the next succeeding Business Day, and interest shall accrue to such day. Prior to the Commitment Termination Date, the Borrowers may borrow, repay and reborrow hereunder at any time and from time to time as provided in the Loan Agreement. From and after the Commitment Termination Date, the Borrowers may prepay this Note in whole or in part, subject to the prepayment limitations contained in the Loan Agreement; provided, however, that any partial prepayment shall be applied first to accrued interest, then to unpaid principal installments in the inverse order of maturity. From time to time the Borrowers and the Banks may agree to extend the maturity date of this Note or to renew this Note, in whole or in part, or a new note of different form may be substitut- ed for this Note and/or the rate of interest may be changed, or changes may be made in consideration of loan extensions, and the holder, from time to time, may waive or surrender, either in whole or in part, any rights, guarantees, security interests, or liens given for the benefit of the holder in connection with the payment and the securing the payment of this Note; but no such occurrences shall in any manner affect, limit, modify or otherwise impair any rights, guarantees or security of the holder not specifically waived, released or surrendered in writing, nor shall the Borrowers or any guarantor, endorser or any other person who is or might be liable hereon, either primarily or contingently, be released from such liability by reason of the occurrence of any such event. The holder hereof, from time to time, shall have the unlimited right to release any person who might be liable hereon; and such release shall not affect or discharge the liability of any other person who is or might be liable hereon. If any payment required by this Note to be made is not made within ten (10) Business Days after the same shall become due and payable, or if any default occurs under the Loan Agreement, the Security Agreement or under the provisions of any mortgage, deed of trust, security agreement, assignment, pledge or other document or agreement which provides security for the indebtedness evidenced by this Note, the holder hereof may, at its option, without notice or demand, declare this Note in default and all indebtedness due and owing hereunder immediately due and payable. In the event of a default the entire unpaid balance shall be immediately due and payable, together with any past due interest at the rate of five percentage points (5%) per annum above the Applicable Prime Rate 2 ("Default Rate"). The Borrowers and all endorsers, guarantors and sureties hereby severally waive protest, presentment, demand, and notice of protest and nonpayment in case this Note or any payment due hereunder is not paid when due; and they agree to any renewal of this Note or to any extension, acceleration or postponement of the time of payment, or any other indulgence, to any substituting, exchange or release of collateral and to the release of any party or person primarily or contingently liable hereon without prejudice to the holder and without notice to the Borrowers or any endorser, guarantor or surety. In the event of any controversy, claim or dispute between the parties affecting or relating to the subject matter or performance of this Note, the prevailing party shall be entitled to recover from the non-prevailing party all of its reasonable costs, expenses, including reasonable attorneys' and accountants' fees. In the event the Agent or ANB is the prevailing party, the Borrowers, and any guarantor, endorser, surety or any other person who is or may become liable hereon, will, on demand, pay all such costs and expenses. Upon the occurrence of any default hereunder, ANB shall have the right, immediately and without further action by it, to set off against this Note all money owed by ANB in any capacity, to each or any of the Borrowers, guarantor, endorser or any other person who is or might be liable for payment hereof, whether or not due, and also to set off against all other liabilities of each of the Borrowers to ANB all money owed by ANB in any capacity to each or any of the Borrowers; and ANB shall be deemed to have exercised such right of setoff and to have made a charge against such money immediately upon the occurrence of such default even though such charge is made or entered into the books of ANB subsequently thereto. This Note is issued pursuant to and subject to the terms of the Loan Agreement and is secured by the Collateral described in the Loan Agreement, which provides, among other things, for prepayment of this Note upon the occurrence of certain events and for limitations on advances which may be made hereunder. Capital- ized terms used and not otherwise defined herein shall have the meanings assigned to them in the Loan Agreement. This Note shall be governed by and construed in accordance with the laws of the State of Oklahoma. Borrowers agree that all suits or proceedings arising from or related to this Note or the Loan Agreement may be litigated in courts, state or federal, sitting in the State of Oklahoma. In furtherance of this provi- sion, Borrowers hereby waive any objection to such venue. 3 Notwithstanding the single execution of this Note by the President of each of the Borrowers, each of the Borrowers is jointly and severally bound by the terms of this Note. "Borrowers" UNIT CORPORATION, a Delaware corporation UNIT DRILLING AND EXPLORATION COMPANY, a Delaware corporation MOUNTAIN FRONT PIPELINE COMPANY, INC., an Oklahoma corporation UNIT PETROLEUM COMPANY, an Oklahoma corporation UNIT DRILLING COMPANY, an Oklahoma corporation PETROLEUM SUPPLY COMPANY, an Oklahoma corporation ROUNDUP RESOURCES, INC., a Delaware corporation By___________________________________ John G. Nikkel, President of UNIT CORPORATION, UNIT DRILLING AND EXPLORATION COMPANY, MOUNTAIN FRONT PIPELINE COMPANY, INC., UNIT PETRO- LEUM COMPANY, UNIT DRILLING COMPA- NY, PETROLEUM SUPPLY COMPANY, ROUNDUP RESOURCES, INC. Due: August 31, 1997 (subject to conversion to Term Loan payout on August 31, 1997 per Loan Agreement) 4