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                                                                    EXHIBIT 4.33

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                       TRANSAMERICAN REFINING CORPORATION,

                                   as Issuer,



                                       and



                           FIRST UNION NATIONAL BANK,

                                   as Trustee



                            ------------------------


                          FIRST SUPPLEMENTAL INDENTURE

                        Effective as of December 15, 1998

                           --------------------------



               $25,000,000 16% Senior Subordinated Notes due 2003



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                          FIRST SUPPLEMENTAL INDENTURE



         THIS FIRST SUPPLEMENTAL INDENTURE, effective as of December 15, 1998
(the "Supplemental Indenture"), is made and entered into by and among
TRANSAMERICAN REFINING CORPORATION, a Texas corporation (the "Company"), and
FIRST UNION NATIONAL BANK (the "Trustee"), under an Indenture dated as of March
16, 1998, by and between the Company and the Trustee (the "Original Indenture").
All capitalized terms used in this Supplemental Indenture that are defined in
the Original Indenture, either directly or by reference therein, have the
respective meanings assigned to them therein, except to the extent such terms
are otherwise defined in this Supplemental Indenture or the context clearly
requires otherwise.

         WHEREAS, Section 9.2 of the Original Indenture provides, among other
things, that, with the consent of the Holders of not less than a majority in
aggregate Value of then outstanding Notes or, with respect to certain matters,
not less than 66-2/3% in aggregate Value of the Notes at the time outstanding,
the Company, when authorized by Board Resolutions, and the Trustee may amend or
supplement the Original Indenture or the Security Documents or enter into an
indenture supplemental thereto for the purposes of adding any provisions to or
changing in any manner or eliminating any of the provisions of the Original
Indenture or the Security Documents or of modifying in any manner the rights of
the Holders under the Original Indenture or the Notes; and

         WHEREAS, the Company has solicited consents from the Holders of the
Notes (the "Consent Solicitation") to amendments (the "Proposed Amendments") to
(i) the Original Indenture and (ii) the Registration Rights Agreement dated
March 16, 1998 by and among the Company and Jefferies & Company, Inc.; and

         WHEREAS, the Holders of at least 66-2/3% in aggregate Value of Notes at
the time outstanding have consented to the Proposed Amendments pursuant to the
Consent Solicitation; and

         WHEREAS, the Board of Directors of the Company has adopted resolutions
authorizing and approving the Proposed Amendments and the Company and the
Trustee are executing and delivering this Supplemental Indenture in order to
provide for such amendments;

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties to this Supplemental
Indenture hereby agree as follows:


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                                    ARTICLE I
                        AMENDMENTS TO ORIGINAL INDENTURE

         Section 1.01. Amended Definitions. The following definitions in Section
1.1 of the Original Indenture are hereby amended as follows:

         (a) The definition of "Accounts Receivable Subsidiary" is hereby
         amended to read in its entirety as follows:

                  "Accounts Receivable Subsidiary" means a subsidiary of TEC,
             the Company, TCR Holding or TransContinental designated as an
             Accounts Receivable Subsidiary for the purpose of financing the
             accounts receivable of TransContinental.

         (b) The definition of "Affiliate" is hereby amended to read in its
         entirety as follows:

                  "Affiliate" means, with respect to any specified Person, (i)
             any other Person directly or indirectly controlling or controlled
             by, or under direct or indirect common control with, such specified
             Person or (ii) any officer, director or controlling shareholder of
             such other Person. For purposes of this definition, the term
             "control" means (a) the power to direct the management and policies
             of a Person, directly or through one or more intermediaries,
             whether through the ownership of voting securities, by contract, or
             otherwise, or (b) without limiting the foregoing, the beneficial
             ownership of 10% or more of the voting power of the voting common
             equity of such Person (on a fully diluted basis) or of warrants or
             other rights to acquire such equity (regardless of whether
             presently exercisable). Notwithstanding the foregoing, none of the
             Purchasers shall be deemed to be "Affiliates" of the Company or any
             of its Subsidiaries.

         (c) The definition of "Capital Improvement Program" is hereby amended
         to read in its entirety as follows:

                  "Capital Improvement Program" means the expansion and
             improvement program at the Company (or, after the Transaction
             Closing Date, TransContinental).

         (d) The definition of "CATOFIN(R) Unit" is hereby amended to read in
         its entirety as follows:

                  "CATOFIN(R) Unit" means certain real property owned by the
             Company before the Transaction Closing Date as more specifically
             defined in the security documents relating to the TEC Notes,
             together with all personal property of TransContinental now or
             hereinafter located on such real property but only to the extent
             that such property is part of a refining unit designed to produce
             propane and butane mono-olefins using the CATOFIN(R) process.

         (e) The definition of "Change of Control" is hereby deleted in its
         entirety.

         (f) The definition of "Consolidated Fixed Charge Coverage Ratio" is
         hereby amended to read in its entirety as follows:



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                  "Consolidated Fixed Charge Coverage Ratio" on any date (the
             "Transaction Date") means, with respect to any Person, the ratio,
             on a pro forma basis, of (i) (x) with respect to any Person other
             than TCR Holding, the aggregate amount of Consolidated EBITDA of
             such Person (attributable to continuing operations and businesses
             and exclusive of the amounts attributable to operations and
             businesses discontinued or disposed of, on a pro forma basis as if
             such operations and businesses were discontinued or disposed of on
             the first day of the Reference Period) for the Reference Period or
             (y) with respect to TCR Holding, the aggregate amount of dividends
             and other distributions on the Capital Stock of TransContinental
             received by TCR Holding from TransContinental during the Reference
             Period to (ii) the aggregate Consolidated Fixed Charges of such
             Person (exclusive of amounts attributable to discontinued
             operations and businesses on a pro forma basis as if such
             operations and businesses were discontinued or disposed of on the
             first day of the Reference Period, but only to the extent that the
             obligations giving rise to such Consolidated Fixed Charges would no
             longer be obligations contributing to such Person's Consolidated
             Fixed Charges subsequent to the Transaction Date) during the
             Reference Period; provided, that for purposes of such computation,
             in calculating Consolidated EBITDA and Consolidated Fixed Charges,
             (a) the transaction giving rise to the need to calculate the
             Consolidated Fixed Charge Coverage Ratio shall be assumed to have
             occurred on the first day of the Reference Period, (b) the
             incurrence of any Debt or issuance of Disqualified Capital Stock or
             the retirement of any Debt or Capital Stock during the Reference
             Period or subsequent thereto and on or prior to the Transaction
             Date shall be assumed to have occurred on the first day of such
             Reference Period, (c) Consolidated Interest Expense attributable to
             any Debt (whether existing or being incurred) bearing a floating
             interest rate shall be computed as if the rate in effect on the
             Transaction Date had been the applicable rate for the entire
             period, unless such Person or any of its Subsidiaries is a party to
             a Swap Obligation (that remains in effect for the 12-month period
             after the Transaction Date) that has the effect of fixing the
             interest rate on the date of computation, in which case such rate
             (whether higher or lower) shall be used.

         (g) The definitions of "Construction Supervisor" and "Debt" are hereby
         amended to read in their entirety as follows:

                  "Construction Supervisor" means Baker & O'Brien, Inc., as
             construction supervisor of the Capital Improvement Program or any
             successor construction supervisor appointed by TEC with the
             approval of TCR Holding, which approval shall not be unreasonably
             withheld.

                  "Debt" means with respect to any person, without duplication
             (i) all liabilities, contingent or otherwise, of such Person (a)
             for borrowed money (whether or not the recourse of the lender is to
             the whole of the assets of such Person or only to a portion
             thereof), (b) evidenced by bonds, notes, debentures, or similar
             instruments or letters of credit or representing the balance
             deferred and unpaid of the purchase price of any property acquired
             by such Person or services received by such Person (other than
             long-term services or supply contracts which required minimum
             periodic payments), (c) evidenced by bankers' acceptances or
             similar instruments issued or accepted by banks or Swap
             Obligations, (d) for the payment of money relating to a Capitalized
             Lease Obligation, (e) the Attributable Debt associated with any
             Sale and Leaseback Transaction or (f) Dollar- 


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             Denominated Production Payments that TransTexas or any of its
             Subsidiaries elect to treat as Debt (excluding all other Permitted
             Production Payment Obligations); (ii) reimbursement obligations of
             such Person with respect to letters of credit; (iii) all
             liabilities of others of the kind described in the preceding clause
             (i) or (ii) that such Person has guaranteed or that is otherwise
             its legal liability (to the extent of such guaranty or other legal
             liability) other than for endorsements, with recourse, of
             negotiable instruments in the ordinary course of business; (iv) all
             obligations secured by a Lien (other than Permitted Liens, except
             to the extent the obligations secured by such Permitted Liens are
             otherwise included in clause (i), (ii) or (iii) of this definition
             and are obligations of such Person) to which the property or assets
             (including, without limitation, leasehold interests and any other
             tangible or intangible property rights) of such Person are subject,
             regardless of whether the obligations secured thereby shall have
             been assumed by or shall otherwise be such Person's legal liability
             (but, if such obligations are not assumed by such Person or are not
             otherwise such Person's legal liability, the amount of such Debt
             shall be deemed to be limited to the fair market value of such
             property or assets determined as of the end of the preceding fiscal
             quarter); and (v) any and all deferrals, renewals, extensions,
             refinancings, and refundings (whether direct or indirect) of, or
             amendments, modifications, or supplements to, any liability of the
             kind described in any of the preceding clauses (i) through (iv)
             regardless of whether between or among the same parties.
             Notwithstanding anything to the contrary contained herein, for
             purposes of Section 4.11, notes issued in satisfaction of the
             interest obligation on up to $150 million principal amount of 15%
             Senior Secured Notes due 2003 issued pursuant to the Transaction in
             accordance with the terms thereof shall not constitute Debt except
             for purposes of the third to last and second to last paragraphs of
             Section 4.11.


         (h) The definition of "Disqualified Capital Stock" is hereby amended to
         read in its entirety as follows:

                  "Disqualified Capital Stock" means, with respect to any
             Person, any Capital Stock of such Person or its Subsidiaries that,
             by its terms of any security into which it is convertible or
             exchangeable, is, or upon the happening of an event or the passage
             of time would be, required to be redeemed or repurchased by such
             Person or its Subsidiaries, including at the option of the holder,
             in whole or in part, or has, or upon the happening of an event or
             passage of time would have, a redemption or similar payment due, on
             or prior to June 30, 2003.

         (i) The definition of "Gas Purchase Agreement" is hereby amended to
         read in its entirety as follows:

                  "Gas Purchase Agreement" means the Interruptible Gas Sales
             Terms and Conditions between the Company and TransTexas, as in
             effect on the Series A/B Issue Date and as amended from time to
             time, provided that any such amendment is approved by the Board of
             Directors of each of the parties thereto.

         (j) The definition of "Insurance Proceeds" is hereby amended to read in
         its entirety as follows:



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                  "Insurance Proceeds" means the interest in and to all proceeds
             (net of costs of collection, including attorney's fees) which now
             or hereafter may be paid under any insurance policies now or
             hereafter obtained by or on behalf of the Company, TEC, TCR
             Holding, TransContinental, TransTexas, or any Guarantor in
             connection with any assets thereof, together with interest payable
             thereon and the right to collect and receive the same, including,
             without limitation, proceeds of casualty insurance, title
             insurance, business interruption insurance and any other insurance
             now or hereafter maintained with respect to such assets.

         (k) The definition of "Permitted Investment" is hereby amended to read
         in its entirety as follows:

                  "Permitted Investment" means, when used with reference to the
             Company or its Subsidiaries, (i) trade credit extended to persons
             in the ordinary course of business; (ii) purchases of Cash
             Equivalents; (iii) Investments by any of the TARC Entities or any
             of the TCR Holding Entities in any of the TCR Holding Entities or
             in TransContinental and Investments by any of the TCR Holding
             Entities in any of the TARC Entities; (iv) Swap Obligations; (v)
             the receipt of Capital Stock in lieu of cash in connection with the
             settlement of litigation; (vi) advances to officers and employees
             in connection with the performance of their duties in the ordinary
             course of business in an amount not to exceed $3 million in the
             aggregate outstanding at any time; (vii) margin deposits in
             connection with Permitted Hedging Transactions; (viii) an
             Investment in one or more Unrestricted Subsidiaries of the Company
             in an aggregate amount not in excess of $10,000,000 since the
             Series A/B/ Issue Date (net of returns on investment) plus the
             assets comprising the CATOFIN(R) Unit owned by the Company as of
             the date hereof, less the amount of any Unrestricted Non-Recourse
             Debt outstanding of the Company or any of its Subsidiaries; (ix)
             deposits permitted by the definition of Permitted Liens or any
             extension, renewal, or replacement of any of them; (x) Investments
             in Accounts Receivables Subsidiary Notes by any of the TARC
             Entities or any of the TCR Holding Entities in amounts not to
             exceed the greater of $20 million or 20% of the TransContinental
             Borrowing Base at any one time; (xi) Investments by the Company in
             a reincorporation subsidiary in connection with the initial
             capitalization thereof and not to exceed $1,000 since the Series
             A/B Issue Date; (xii) Investments by the Company or any of its
             wholly owned Subsidiaries in an aggregate amount not to exceed
             $250,000 since the Series A/B Issue Date, for the purpose of
             facilitating a redemption, repurchase or other retirement for value
             of the Old TARC Warrants or the conversion of the Old TARC Warrants
             into the right to receive cash; (xiii) a guaranty by a Subsidiary
             of the Company permitted under clause (h) of Section 4.11; (xiv)
             deposits permitted by the definition of "Permitted Liens" or any
             extension, renewal, or replacement of any of them; (xv) other
             Investments not in excess of $5 million at any time outstanding;
             (xvi) loans made (X) to officers, directors and employees of the
             Company or any of its Subsidiaries approved by the applicable Board
             of Directors (or by an authorized officer), the proceeds of which
             are used solely to purchase stock or to exercise stock options
             received pursuant to an employee stock option plan or other
             incentive plan, in a principal amount not to exceed the purchase
             price of such stock or the exercise price of such stock options, as
             applicable and (Y) to refinance loans, together with accrued
             interest thereon made pursuant to this clause, in each case not in
             excess of $3 million in the aggregate outstanding at any one time,
             (xvii) Investments in money market mutual or similar funds having
             assets in excess of $100,000,000 and (xviii)



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             the purchase or other acquisition by TARC, TCR Holding and their
             Subsidiaries of TEC Notes or by TCR Holding and its Subsidiaries of
             Notes or Series A/B Notes.

         (l) The definition of "Permitted Liens" is hereby amended to read in
         its entirety as follows:

                  "Permitted Liens" means (a) Liens imposed by governmental
             authorities for taxes, assessments, or other charges not yet due or
             which are being contested in good faith and by appropriate
             proceedings, if adequate reserves with respect thereto are
             maintained on the books of the Company or any of its Subsidiaries
             in accordance with GAAP; (b) statutory Liens of landlords,
             carriers, warehousemen, mechanics, materialmen, repairmen, mineral
             interest owners, or other like Liens arising by operation of law in
             the ordinary course of business provided that (i) the underlying
             obligations are not overdue for a period of more than 60 days, or
             (ii) such Liens are being contested in good faith and by
             appropriate proceedings and adequate reserves with respect thereto
             are maintained on the books of the Company or any of its
             Subsidiaries in accordance with GAAP; (c) deposits of cash or Cash
             Equivalents to secure (i) the performance of bids, trade contracts
             (other than borrowed money), leases, statutory obligations, surety
             bonds, performance bonds, and other obligations of a like nature
             incurred in the ordinary course of business (or to secure
             reimbursement obligations or letters of credit issued to secure
             such performance or other obligations) in an aggregate amount
             outstanding at any one time not in excess of $5 million or (ii)
             appeal or supersedeas bonds (or to secure reimbursement obligations
             or letters of credit in support of such bonds); (d) easements,
             servitudes, rights-of-way, zoning, similar restrictions and other
             similar encumbrances or title defects incurred in the ordinary
             course of business which, in the aggregate, are not material in
             amount and which do not, in any case, materially detract from the
             value of the property subject thereto (as such property is used by
             any of the TARC Entities) or materially interfere with the ordinary
             conduct of the business of any of the TARC Entities including
             without limitation, any easement or servitude granted in connection
             with the financing of the Storage Assets; (e) Liens arising by
             operation of law in connection with judgments, only to the extent,
             for an amount and for a period not resulting in an Event of Default
             with respect thereto; (f) Liens securing Debt or other obligations
             not in excess of $3 million; (g) pledges or deposits made in the
             ordinary course of business in connection with worker's
             compensation, unemployment insurance, other types of social
             security legislation, property insurance and liability insurance;
             (h) Liens on Equipment, Receivables and Inventory; (i) Liens on the
             assets of any entity existing at the time such assets are acquired
             by any of the TARC Entities, whether by merger, consolidation,
             purchase of assets or otherwise so long as such Liens (i) are not
             created, incurred or assumed in contemplation of such assets being
             acquired by any of the TARC Entities and (ii) do not extend to any
             other assets of any of the TARC Entities; (j) Liens (including
             extensions and renewals thereof) on real or personal property,
             acquired after the Series A/B Issue Date ("New Property");
             provided, however, that (i) such Lien is created solely for the
             purpose of securing Debt Incurred to finance the cost (including
             the cost of improvement or construction) of the item of New
             Property subject thereto and such Lien is created at the time of or
             within six months after the later of the acquisition, the
             completion of construction, or the commencement of full operations
             of such New Property, (ii) the principal amount of the Debt secured
             by such Lien does not exceed 100% of such costs plus reasonable
             financing fees and other associated reasonable out-of-pocket
             expenses and (iii) any such Lien shall not extend to or cover any
             property or assets other than such item of


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             New Property and any improvements on such New Property; (k) leases
             or subleases granted to others that do not materially interfere
             with the ordinary course of business of any of the TARC Entities,
             taken as a whole; (l) Liens on the assets of one of the TARC
             Entities in favor of another TARC Entity; (m) Liens securing
             reimbursement obligations with respect to letters of credit that
             encumber documents relating to such letters of credit and the
             products and proceeds thereof; provided, that, such reimbursement
             obligations are not matured for a period of over 60 days; (n) Liens
             in favor of customs and revenue authorities arising as a matter of
             law to secure payment of customs duties in connection with the
             importation of goods; (o) Liens encumbering customary initial
             deposits and margin deposits securing Swap Obligations or Permitted
             Hedging Transactions and Liens encumbering contract rights under
             Permitted Hedging Transactions; (p) Liens on cash deposits to
             secure reimbursement obligations with respect to letters of credit
             after the Delayed Coking Unit is completed; (q) Liens that secure
             Unrestricted Non-Recourse Debt; provided, however, that at the time
             of incurrence the aggregate fair market value of the assets
             securing such Lien (exclusive of the stock of the applicable
             Unrestricted Subsidiary) shall not exceed the amount of allowed
             Unrestricted Non-Recourse Debt of the Company or TCR Holding; (r)
             Liens on the proceeds of any property subject to a Permitted Lien
             and Liens on the proceeds of any Debt Incurred in accordance with
             the provisions hereof, or on deposit accounts containing any such
             proceeds; (s) Liens imposed in connection with Debt incurred
             pursuant to clause (f) of Section 4.11; provided, that such liens,
             if not Permitted Liens, do not extend to property other than the
             Storage Assets, the proceeds of financing related to the Storage
             Assets or deposit accounts containing such proceeds; and (t) any
             extension, renewal or replacement of the Liens created pursuant to
             any of clauses (a) through (g), (i) through (s) or (u) provided
             that such Liens would have otherwise been permitted under such
             clauses, and provided further that the Liens, permitted by this
             clause (t) do not secure any additional Debt or encumber any
             additional property; (u) Liens that secure Senior Debt; (v) Liens
             on any property of the Company or its Subsidiaries (or any
             agreement to grant such Liens) securing the Series A/B Notes or the
             Notes, (w) Liens on any Property owned by TransContinental and (x)
             Liens on any Property owned by the Company or TCR Holding to secure
             Debt permitted by clause (s) of Section 4.11.

         (m) The definition of "Phase I Completion Date" is hereby amended to
         read in its entirety as follows:

                  "Phase I Completion Date" means the date on which the
             Construction Supervisor issues a written notice (the "Phase I
             Completion Notice") to TEC certifying that the Phase I Performance
             Test has been completed.


         (n) A definition of "Phase I Performance Test " is hereby added to the
         Original Indenture to read in its entirety as follows:

                  "Phase I Performance Test" means for a period of at least 72
             uninterrupted hours, TransContinental's refinery has sustained (i)
             an average feedstock throughput level of at least 150,000 barrels
             per day and (ii) no net production of vacuum tower bottoms when
             using as input a combined feedstock slate with an average API
             Gravity of 22 degrees or less.


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         (o) The definition of "Phase II Completion Date" is hereby amended to
         read in its entirety as follows:

                  "Phase II Completion Date" means the date on which the
             Construction Supervisor issues a written notice (the "Phase II
             Completion Notice") to TEC certifying that for a period of at least
             72 uninterrupted hours, TransContinental's refinery has sustained
             (i) an average feedstock throughput level of at least 180,000
             barrels per day and (ii) average production yields (measured as the
             liquid volume percent of feedstock throughput) of refined products
             with a specific gravity of gasoline or lighter of at least 40% and
             of middle distillates or lighter of at least 60%, when using a
             combined Crude Unit feedstock slate with an average API Gravity of
             22 degrees or less.

         (p) The definition of "Plans" is hereby amended to read in its entirety
         as follows:

                  "Plans" means (a) the plans and specifications prepared by or
             on behalf of the Company (or, after the Transaction Closing Date,
             TransContinental), which describe and show the proposed expansion
             and modification of the Company's (or, after the Transaction
             Closing Date, TransContinental's) refinery as amended from time to
             time with the consent of the Construction Supervisor and (b) a
             budget prepared by or on behalf of the Company (or, after the
             Transaction Closing Date, TransContinental) as amended from time to
             time with the consent of the Construction Supervisor.

         (q) A definition of "Purchasers" is hereby added to the Original
         Indenture to read in its entirety as follows:

                  "Purchasers" means the initial purchasers from TARC pursuant
             to the Transaction of voting stock of TCR Holding and their
             transferees and Affiliates (in each case other than the Company and
             its Subsidiaries).

         (r) A definition of "Refinery Assets" is hereby added to the Original
         Indenture to read in its entirety as follows:

                  "Refinery Assets" means substantially all of the assets of
             TARC immediately prior to the Transaction Closing Date.

         (s) The definition of "Related Persons" is hereby amended to read in
         its entirety as follows:

                  "Related Person" means (i) any Person (other than a Purchaser
             or TransContinental and any of its Subsidiaries) directly or
             indirectly controlling or controlled by or under direct or indirect
             common control with the Company or any Subsidiary of the Company or
             any officer, director, or employee of the Company or any Subsidiary
             of the Company or of such Person, (ii) the spouse, any immediate
             family member, or any other relative who has the same principal
             residence of any Person described in clause (i) above, and any
             Person, directly or indirectly, controlling or controlled by or
             under direct or indirect common control with, such spouse, family
             member, or other relative, and (iii) any trust in which any Person
             described in clause (i) or (ii), above, is a fiduciary or has a
             beneficial interest. For purposes of this definition the term
             "control" means (a) the power


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             to direct the management and policies of a Person, directly or
             through one or more intermediaries, whether through the ownership
             of voting securities, by contract, or otherwise, or (b) the
             beneficial ownership of 10% or more of the voting common equity of
             such Person (on a fully diluted basis) or of warrants or other
             rights to acquire such equity (whether or not presently
             exercisable).

         (t) The definition of "Restricted Payment" is hereby amended to read in
         its entirety as follows:

                  "Restricted Payment" means, with respect to any Person, (i)
             any Restricted Investment, (ii) any dividend or other distribution
             on shares of Capital Stock of such Person or any Subsidiary of such
             Person (iii) any payment on account of the purchase, redemption, or
             other acquisition or retirement for value of any shares of Capital
             Stock of such Person, and (iv) any defeasance, redemption,
             repurchase, or other acquisition or retirement for value, or any
             payment in respect of any amendment in anticipation of or in
             connection with any such retirement, acquisition, or defeasance, in
             whole or in part, of any Pari Passu Debt or Subordinated Debt,
             directly or indirectly, of such Person or a Subsidiary of such
             Person prior to the scheduled maturity or prior to any scheduled
             repayment of principal in respect of such Pari Passu Debt or
             Subordinated Debt; provided, however, that the term "Restricted
             Payment" does not include (i) any dividend, distribution, or other
             payment on shares of Capital Stock of an issuer solely in shares of
             Qualified Capital Stock of such issuer that is at least as junior
             in ranking as the Capital Stock on which such dividend,
             distribution, or other payment is to be made, (ii) any dividend,
             distribution, or other payment to the Company from TCR Holding or
             from any of the Company's Subsidiaries or to TCR Holding by any of
             TCR Holding's Subsidiaries, (iii) any defeasance, redemption,
             repurchase, or other acquisition or retirement for value, in whole
             or in part, of any Pari Passu Debt or Subordinated Debt of such
             Person payable solely in shares of Qualified Capital Stock of such
             Person, (iv) any payments or distributions made pursuant to and in
             accordance with the Services Agreement, the Expense Reimbursement
             Agreement, the Office Leases, the Transfer Agreement or the Tax
             Allocation Agreement, (v) any redemption, repurchase or other
             retirement for value of the Old TARC Warrants by the Company,
             including any premium paid thereon, (vi) the redemption, purchase,
             retirement or other acquisition of any Debt including any premium
             paid thereon, with the proceeds of any refinancing Debt permitted
             to be incurred pursuant to clauses (o), (s) and (u) of the covenant
             described herein under the heading "Limitation on the Incurrences
             of Additional Debt and Issuances of Disqualified Capital Stock,"
             (vii) the purchase by the Company or TCR Holding of shares of
             Capital Stock of the Company, TCR Holding, TransContinental,
             TransTexas or TTXD in connection with each of its employee benefit
             plans, including without limitation any employee stock ownership
             plans or any employee stock option plans, in an aggregate amount,
             with respect to the issuer, not to exceed 7% of the aggregate
             number of shares of voting stock held by nonaffiliates of the
             issuer measured from the date of the first such purchase, (viii)
             distributions of common stock of TransTexas to TEC, (ix) any
             dividend or other distribution on the Capital Stock of any
             Subsidiary of the Company, (x) any purchase of Capital Stock of TCR
             Holding by the Company, (xi) any purchase of Capital Stock of
             TransContinental by TCR Holding, (xii) any dividend or payment on
             shares of Capital Stock of TCR Holding the proceeds of the issuance
             of which are used to purchase TEC Notes and (xiii) the TCR Holding
             Participating Preferred Stock Redemption.



                                      -10-
   11



         (u) The definition of "Senior Debt" is hereby amended to read in its
         entirety as follows:

                  "Senior Debt" means, all Debt of the Company or, with respect
             to its use in the definition of "Permitted Liens" only, TCR
             Holding, including, without limitation, the TARC Discount Notes,
             the TARC Mortgage Notes, the TARC Working Capital Loan and the TARC
             Intercompany Loan, now or hereafter created, incurred, assumed or
             guaranteed by the Company (and all renewals, extensions or
             refundings thereof or of any part thereof) (including the principal
             of, interest on and fees, premiums, expenses (including costs of
             collection), indemnities and other amounts payable in connection
             with such Indebtedness, and including Post-Commencement Amounts),
             unless the instrument governing such Debt expressly provides that
             such Debt is not senior or superior in right of payment to the
             Notes. Notwithstanding the foregoing, Senior Debt of the Company
             shall not include (i) Debt evidenced by the Series A/B Notes and
             the Notes, (ii) Debt of the Company to any Subsidiary of the
             Company or to any Unrestricted Subsidiary of the Company (other
             than to facilitate the purchase of the common stock purchase
             warrants of TARC), or (iii) any amounts payable or other Debt to
             trade creditors created, incurred, assumed or guaranteed by the
             Company or any Subsidiary of the Company in the ordinary course of
             business in connection with obtaining goods or services.

         (v) The definition of "Services Agreement" is hereby amended to read in
         its entirety as follows:

                  "Services Agreement" means the Services Agreement among TNGC
             Holdings and its Subsidiaries, as in effect on the Series A/B Issue
             Date and as amended from time to time, provided that any such
             amendment is approved by the Board of Directors of each of the
             parties thereto that will be bound by such amendment.

         (w) The definition of "Subsidiary" is hereby amended to read in its
         entirety as follows:

                  "Subsidiary" with respect to any Person, means (i) a
             corporation with respect to which such Person or its Subsidiaries
             owns, directly or indirectly, at least fifty percent of such
             corporation's Capital Stock with voting power, under ordinary
             circumstances, to elect directors, or (ii) a partnership in which
             such Person or a subsidiary of such Person is, at the time, a
             general partner of such partnership and has more than 50% of the
             total voting power of partnership interests entitled (without
             regard to the occurrence of any contingency) to vote in the
             election of managers thereof, or (iii) any other Person (other than
             a corporation or a partnership) in which such Person, one or more
             Subsidiaries of such Person, or such Person and one or more
             Subsidiaries of such Person, directly or indirectly, at the date of
             determination thereof has (x) at least a fifty percent ownership
             interest or (y) the power to elect or direct the election of the
             directors or other governing body of such other Person; provided,
             however, that "Subsidiary" shall not include (i) for the purposes
             of the Indenture provisions "Subsidiary Guarantees," and
             "Limitation on Transactions with Related Persons" a joint venture
             an investment in which would constitute a Permitted Investment,
             provided that, for purposes of the covenant described herein under
             the heading "Limitation on Transactions with Related Persons," such
             investment is not with a Related Person other than solely because
             the party engaging in such transaction has the ability to control
             the Related Person under the definition of "Control" contained
             within the definition of Related Person or (ii) any Unrestricted
             Subsidiary of such Person; provided,


                                      -11-
   12



             further, however, that TCR Holding and its subsidiaries other than
             TransContinental shall be "Subsidiaries" of TARC (except for
             purposes of Section 4.16) and TransContinental shall not be a
             "Subsidiary" of any Person.

         (x) The definition of "TARC Intercompany Loan" is hereby amended to
         read in its entirety as follows:

                  "TARC Intercompany Loan" means the senior secured promissory
             note from the Company to TEC in the fully accreted principal amount
             of $920,000,000 upon substantially the terms described in the
             Registration Statement on Form S-4, as amended, of TEC under the
             heading "Description of Existing Indebtedness -- TARC Intercompany
             Loan" and as amended from time to time in accordance with its
             terms.

         (y) A definition of "TARC Intercompany Loan Amendment" is hereby added
         to the Original Indenture to read in its entirety as follows:

                  "TARC Intercompany Loan Amendment" means the second amendment
             to the TARC Intercompany Loan Agreement upon substantially the
             terms described in the form attached hereto as Exhibit C.

         (z) A definition of "TransContinental" is hereby added to the Original
         Indenture to read in its entirety as follows:

                  "TransContinental" means TransContinental Refining
             Corporation, a Delaware corporation, to which the Refinery Assets
             will be transferred by TCR Holding pursuant to the Transaction and,
             for purposes of Section 4.11 hereof, its Subsidiaries.

         (aa) The definition of "TARC Borrowing Base" is hereby amended to read
         in its entirety as follows:

                  "TransContinental Borrowing Base" means, as of any date, an
             amount equal to the sum of (a) 90% of the book value of all
             accounts receivable owned by TransContinental and its Subsidiaries
             (excluding any accounts receivable that are more than 90 days past
             due, less (without duplication) the allowance for doubtful accounts
             attributable to such current accounts receivable) calculated on a
             consolidated basis and in accordance with GAAP and (b) 85% of the
             current market value of all inventory owned by TransContinental and
             its Subsidiaries as of such date. To the extent that information is
             not available as to the amount of accounts receivable as of a
             specific date, TransContinental may utilize, to the extent
             reasonable, the most recent available information for purposes of
             calculating the TransContinental Borrowing Base.

         (bb) A definition of "TCR Holding" is hereby added to the Original
         Indenture to read in its entirety as follows:

                  "TCR Holding" means TCR Holding Corporation, a Delaware
             corporation, to which the Refinery Assets will be transferred by
             TARC pursuant to the Transaction.



                                      -12-
   13



         (cc) A definition of "TCR Holding Entities" is hereby added to the
         Original Indenture to read in its entirety as follows:

                  "TCR Holding Entities" means TCR Holding and each of its
             Subsidiaries.

         (dd) A definition of "TCR Holding Participating Preferred Stock" is
         hereby added to the Original Indenture to read in its entirety as
         follows:

                  "TCR Holding Participating Preferred Stock" means the
             participating preferred stock of TCR Holding issued pursuant to the
             Transaction.

         (ee) A definition of "TCR Holding Participating Preferred Stock
         Redemption" is hereby added to the Original Indenture to read in its
         entirety as follows:

                  "TCR Holding Participating Preferred Stock Redemption" means
             the redemption by TCR Holding of the TCR Holding Participating
             Preferred Stock in exchange for (i) debt securities of TCR Holding
             with an aggregate principal amount equal to the liquidation
             preference of the TCR Holding Participating Preferred Stock, with a
             maturity date of June 1, 2002 and bearing interest at a rate
             sufficient to pay interest on the TARC Intercompany Loan, the Notes
             and the Series C/D Notes and (ii) common stock of TCR Holding equal
             to 30.6% of the equity interest in TCR Holding and 41% of the
             voting power of TCR Holding's capital stock.

         (ff) A definition of "TARC Intercompany Subordinated Note" is hereby
         added to the Original Indenture to read in its entirety as follows:

                  "TARC Intercompany Subordinated Note" means that certain note
             and related documents (i) evidencing debt of TCR Holding to TARC in
             an amount and with principal and interest payment terms sufficient
             to service the payment of interest and principal on the Notes and
             the Series A/B Notes (after giving effect to any amounts in any
             Interest Reserve Account) and (ii) containing a covenant of TCR
             Holding to pledge the stock it owns of TransContinental, if any, as
             of the date of the payment in full of the TARC Intercompany Loan;
             provided, that TCR Holding shall not be required to grant such Lien
             until the TARC Intercompany Loan has been paid in full and has not
             been refinanced, refunded or replaced with the proceeds of Other
             Debt ("Other Debt"), which Other Debt has a lower cost of capital
             to TCR Holding than the TARC Intercompany Loan and the principal
             amount of such Other Debt (or, if such Other Debt is issued with
             original issue discount, the original issue amount of such Other
             Debt) is equal to or less than the original issue price of, plus
             amortization of the original issue discount on, the TARC
             Intercompany Loan at the time of the incurrence of such Other Debt.

         (gg) A definition of "TARC Working Capital Loan" is hereby added to the
         Original Indenture to read in its entirety as follows:

                  "TARC Working Capital Loan" means a loan by TEC to TARC of up
             to $50 million, which will be assumed by TCR Holding pursuant to
             the Transaction.



                                      -13-
   14


         (hh) The definition of "Tax Allocation Agreement" is hereby amended to
         read in its entirety as follows:

                  "Tax Allocation Agreement" means the Tax Allocation Agreement,
             dated as of August 24, 1993, among TNGC Holdings Corporation, the
             Company, TEC and other subsidiaries of TNGC Holdings Corporation,
             as in effect on the Issue Date and as amended from time to time,
             provided that any such amendment is approved by the Board of
             Directors of each of the parties thereto that will be bound by such
             amendment.

         (ii) A definition of "Transaction" is hereby added to the Original
         Indenture to read in its entirety as follows:

                  "Transaction" means a series of related transactions (as more
             fully described in the Company's Consent Solicitation Statement
             dated October 5, 1998, as amended, pursuant to which consents were
             solicited from the Holders to amendments to the Indenture to
             facilitate the Transaction, which description is incorporated
             herein by reference) pursuant to which, among other things, (i) the
             Lien on the TARC Collateral (as defined in the TEC Indenture) is
             released, (ii) TARC transfers to TCR Holding the Refinery Assets in
             exchange for (x) all of the capital stock of TCR Holding and (y)
             the assumption by TCR Holding of certain debt and other obligations
             of TARC, (iii) TCR Holding transfers to TransContinental the
             Refinery Assets in exchange for all of the common stock of
             TransContinental and TransContinental assumes the debt and other
             obligations of TARC assumed by TCR Holding other than the TARC
             Working Capital Loan and (iv) certain Purchasers purchase (x) debt
             securities issued by TARC, (y) equity securities issued by
             TransContinental and (z) TCR Holding Capital Stock from TARC for
             aggregate gross proceeds of approximately $151 million.

         (jj) A definition of "Transaction Closing Date" is hereby added to the
         Original Indenture to read in its entirety as follows:

                  "Transaction Closing Date" means the date the Refinery Assets
             are transferred by TARC to TCR Holding and by TCR Holding to
             TransContinental pursuant to the Transaction.

         (kk) The definition of "Unrestricted Non-Recourse Debt" is hereby 
         amended to read in its entirety as follows:

                  "Unrestricted Non-Recourse Debt" of the Company,
             TransContinental or any of the Subsidiaries of the Company means
             (i) Debt of such Person that is secured solely (other than with
             respect to clause (ii) below) by a Lien upon the stock of an
             Unrestricted Subsidiary of such Person and as to which there is no
             recourse (other than with respect to clause (ii) below) against
             such Person or any of its assets other than against such stock (and
             the dollar amount of any Debt of such Person as described in this
             clause (i) shall be deemed to be zero for purposes of all other
             provisions of the Indenture) and (ii) guarantees of the Debt of
             Unrestricted Subsidiaries of such Person; provided, that the
             aggregate of all Debt of such Person Incurred and outstanding
             pursuant to clause (ii) of this definition, together with all
             Permitted Investments (net of any return on such Investment) in
             Unrestricted


                                      -14-
   15


             Subsidiaries of such Person, does not exceed (x) 20% of the
             Company's Consolidated EBITDA since the Phase II Completion Date in
             the case of the Company, (y) 20% of TCR Holding's Consolidated
             EBITDA since the Phase II Completion Date in the case of TCR
             Holding or (z) 20% of TransContinental's Consolidated EBITDA since
             the Phase II Completion Date in the case of TransContinental plus
             in the case of clause (ii) of this definition of Unrestricted
             Non-Recourse Debt, Restricted Payments permitted to be made
             pursuant to Section 4.3.

         Section 1.02. Section 4.3 of the Original Indenture. Section 4.3 of the
Original Indenture is hereby amended to read in its entirety as follows:

                  Section 4.3 Limitation on Restricted Payments. The Company
             shall not, and shall not permit any of its Subsidiaries to,
             directly or indirectly, make any dividend or other distribution on
             shares of Capital Stock of the Company or any Subsidiary of the
             Company or make any payment on account of the purchase, redemption,
             or other acquisition or retirement for value of any such shares of
             Capital Stock unless such dividends, distributions, or payments are
             made in cash or Capital Stock or a combination thereof. In
             addition, the Company shall not, and shall not permit any of its
             Subsidiaries to, directly or indirectly, make any Restricted
             Payment; provided, however, that the Company or TCR Holding may
             make a Restricted Payment if, at the time or after giving effect
             thereto on a pro forma basis no Default or Event of Default would
             occur or be continuing, and:

                  (i) in the case of Restricted Payments by the Company:

                      (a) the Company's Consolidated Fixed Charge Coverage Ratio
                  exceeds 2.25 to 1; and

                      (b) the aggregate amount of all Restricted Payments made
                  by all of the TARC Entities, including such proposed
                  Restricted Payment and all payments that may be made pursuant
                  to the proviso at the end of this sentence (if not made in
                  cash, then the fair market value of any property used
                  therefor), from and after the Series A/B Issue Date and on or
                  prior to the date of such Restricted Payment, would not exceed
                  an amount equal to (x) 50% of Adjusted Consolidated Net Income
                  of the Company accrued for the period (taken as one accounting
                  period) from the first full fiscal quarter that commenced
                  after the Series A/B Issue Date to and including the fiscal
                  quarter ended immediately prior to the date of each
                  calculation for which financial statements are available (or,
                  if the Company's Adjusted Consolidated Net Income for such
                  period is a deficit, then minus 100% of such deficit), plus
                  (y) the aggregate Net Proceeds received by the Company from
                  the issuance or sale (other than to a Subsidiary of the
                  Company) of its Qualified Capital Stock from and after the
                  Series A/B Issue Date and on or prior to the date of such
                  Restricted Payment, minus (z) 100% of the amount of any
                  write-downs, write-offs, other negative revaluations, and
                  other negative extraordinary charges not otherwise reflected
                  in the Company's Adjusted Consolidated Net Income during such
                  period; and

                  (ii) in the case of Restricted Payments by TCR Holding:


                                      -15-
   16



                  (a) TCR Holding's Consolidated Fixed Charge Coverage Ratio
                  exceeds 2.25 to 1; and

                  (b) the aggregate amount of all Restricted Payments made by
                  all of the TCR Holding Entities, including such proposed
                  Restricted Payment and all payments that may be made pursuant
                  to the proviso at the end of this sentence (if not made in
                  cash, then the fair market value of any property used
                  therefor), from and after the Transaction Closing Date and on
                  or prior to the date of such Restricted Payment, would not
                  exceed an amount equal to the sum of (w) $1,000,000, plus (x)
                  50% of Adjusted Consolidated Net Income of TCR Holding accrued
                  for the period (taken as one accounting period) from the first
                  full fiscal quarter that commenced after the Transaction
                  Closing Date to and including the fiscal quarter ended
                  immediately prior to the date of each calculation for which
                  financial statements are available (or, if TCR Holding's
                  Adjusted Consolidated Net Income for such period is a deficit,
                  then minus 100% of such deficit), plus (y) the aggregate Net
                  Proceeds received by TCR Holding from the issuance or sale
                  (other than to a Subsidiary of TCR Holding) of its Qualified
                  Capital Stock from and after the Transaction Closing Date and
                  on or prior to the date of such Restricted Payment, minus (z)
                  100% of the amount of any write-downs, write-offs, other
                  negative revaluations, and other negative extraordinary
                  charges not otherwise reflected in TCR Holding's Adjusted
                  Consolidated Net Income during such period;

         provided, that nothing in this Section 4.3 shall prohibit the payment
         of any dividend within 60 days after the date of its declaration if
         such dividend could have been made on the date of its declaration in
         compliance with the foregoing provisions.

         Section 1.03. Section 4.7 of the Original Indenture. Section 4.7(d) of
the Original Indenture is hereby deleted in its entirety.

         Section 1.04. Section 4.8 of the Original Indenture. Section 4.8 of the
Original Indenture is hereby amended to read as follows:

                  Section 4.8 SEC Reports. The Company shall deliver to the
             Trustee and each Holder, within 15 days after it files the same
             with the SEC, copies of all reports and information (or copies of
             such portions of any of the foregoing as the SEC may by rules and
             regulations prescribe), if any, which the Company is required to
             file with the SEC pursuant to Section 13 or 15(d) of the Exchange
             Act. The Company shall include in all such reports and information
             a summary of the status of the Company's Capital Improvement
             Program, including a description of sources of funds available for
             the completion of the Capital Improvements Program. The Company
             agrees to continue to be subject to and comply with the filing and
             reporting requirements of the Commission as long as any of the
             Notes are outstanding.

                  Concurrently with the reports delivered pursuant to the
             preceding paragraph, the Company shall deliver to the Trustee and
             to each Holder annual and quarterly financial statements with
             appropriate footnotes of the Company and its Subsidiaries, all
             prepared and presented in a manner substantially consistent with
             those of the Company required by the


                                      -16-
   17


             preceding paragraph. The Company shall also comply with the other
             provisions of TIA Section 314(a).

                  The Company shall, upon request, provide to each Holder and to
             each beneficial owner and prospective purchaser of Notes identified
             by any Holder of Restricted Notes the information required by
             clause (d)(4) of Rule 144A until the earlier to occur of (i) there
             existing no further necessity for an offer or sale of the Notes to
             qualify for an exemption under such Rule or (ii) the consummation
             of a registered exchange offer for the Notes.

         Section 1.05.  Section 4.10 of the Original Indenture.  Section 4.10 of
the Original Indenture is hereby amended as follows:

         (a) Section 4.10(a) of the Original Indenture is hereby amended to read
in its entirety as follows:

                  (a) The Company shall not, and shall not permit any of its
             Subsidiaries to, enter directly or indirectly into, or permit to
             exist, any transaction or series of related transactions with any
             Related Person (including, without limitation: (i) the sale, lease,
             transfer or other disposition of properties, assets or securities
             to such Related Person, (ii) the purchase or lease of any property,
             assets or securities from such Related Person, (iii) an Investment
             in such Related Person (excluding Investments permitted to be made
             pursuant to clauses (iii), (vi), (viii), (x), (xi), (xii), (xvi)
             and (xviii) of the definition of "Permitted Investment"), and (iv)
             entering into or amending any contract or agreement with or for the
             benefit of a Related Person (each, a "Related Person
             Transaction")), except for (A) permitted Restricted Payments,
             including for this purpose the transactions excluded from the
             definition of Restricted Payments by the proviso contained in the
             definition of "Restricted Payments"; (B) transactions made in good
             faith, the terms of which are (x) fair and reasonable to the
             Company or such Subsidiary, as the case may be, and (y) at least as
             favorable as the terms which could be obtained by the Company or
             such Subsidiary, as the case may be, in a comparable transaction
             made on an arm's length basis with Persons who are not Related
             Persons; (C) transactions between the Company and any of its Wholly
             Owned Subsidiaries or between Wholly Owned Subsidiaries of the
             Company; (D) transactions pursuant to the Services Agreement, the
             Tax Allocation Agreement, the Gas Purchase Agreement, and the
             Expense Reimbursement Agreement, in each case including amendments
             thereto that are approved by the Board of Directors of each of the
             parties thereto that will be bound by such amendments, and the
             Transfer Agreement, the TARC Intercompany Loan and related security
             documents, and the Registration Rights Agreement; (E) the lease of
             office space to the Company or an Affiliate of the Company by
             TransAmerican or an Affiliate of TransAmerican, provided that
             payments thereunder do not exceed in the aggregate $200,000 per
             year; (F) any employee compensation arrangement in an amount which
             together with the amount of all other cash compensation paid to
             such employee by the Company and its Subsidiaries does not provide
             for cash compensation in excess of $5,000,000 in any fiscal year of
             the Company or any Subsidiary and which has been approved by a
             majority of the Company's Independent Directors and found in good
             faith by such directors to be in the best interests of the Company
             or such Subsidiary, as the case may be; (G) loans to the Company
             and TCR Holding which are permitted to be Incurred pursuant to the
             terms of Section 4.11; (H) the amounts payable by the TEC and its
             Subsidiaries to Southeast Contractors for employee services
             provided to the Company or


                                      -17-
   18


             TransContinental not exceeding the actual costs to Southeast
             Contractors of the employees, which costs consist solely of payroll
             and employee benefits, plus related administrative costs and an
             administrative fee, not exceeding $2,000,000 per year in the
             aggregate; (I) the Company and its Subsidiaries may pay a
             management fee to TransAmerican in an amount not to exceed
             $2,500,000 per year; (J) transactions effected pursuant to the
             Transaction, including without limitation (i) the execution,
             delivery and performance of the TARC Intercompany Loan Amendment,
             the TCR Holding Pledge Agreement, an amendment of the Services
             Agreement and a Securities Purchase Agreement among TARC, TCR
             Holding, TransContinental, TEC and certain of the Purchasers
             providing for the sale to such Purchasers of Capital Stock of TCR
             Holding owned by TARC pursuant to the Transaction, (ii) the
             transfer of the Refinery Assets by TARC to TCR Holding and, as
             consideration therefor, the issuance by TCR Holding to TARC of
             Capital Stock of TCR Holding, the assumption by TCR Holding of
             certain debt and obligations of TARC (including Debt of TARC to the
             Purchasers and certain others), and (iii) the transfer of the
             Refinery Assets by TCR Holding to TransContinental and, as
             consideration therefor, the issuance by TransContinental of its
             common stock to TCR Holding and the assumption by TransContinental
             of certain debt and obligations of TCR Holding; (K) the delivery of
             TEC Notes to TEC in satisfaction of the TARC Intercompany Loan; (L)
             the issuance and sale of the TCR Holding Participating Preferred
             Stock; (M) the TCR Holding Participating Preferred Stock
             Redemption; and (N) transactions between or among TCR Holding or
             TransContinental and any of their respective Related Persons,
             provided such transaction is approved by the Board of Directors of
             each of the parties thereto.

         (b) Section 4.10(b) of the Original Indenture is hereby amended to read
         in its entirety as follows:

                  (b) Without limiting the foregoing, except for sales of
             accounts receivable to an Accounts Receivable Subsidiary in
             accordance with Section 4.20, (i) with respect to any Related
             Person Transaction or series of Related Person Transactions (other
             than any Related Person Transaction described in clause (A) (with
             respect to Permitted Restricted Payments by virtue of clauses (i),
             (ii), (iv), (vii), (ix), (x) or (xi) of the proviso contained in
             the definition of "Restricted Payments"), (C), (D), (E), (G), (J),
             (K), (L), (M) or (N) of Section 4.10(a)) with an aggregate value in
             excess of $5,000,000, such transaction must first be approved by a
             majority of the Board of Directors of the Company or its Subsidiary
             which is the transacting party and a majority of the directors of
             such entity who are disinterested in the transaction pursuant to a
             Board Resolution, as (x) fair and reasonable to the Company or such
             Subsidiary, as the case may be, and (y) on terms which are at least
             as favorable as the terms which could be obtained by the Company or
             such Subsidiary, as the case may be, on an arm's length basis with
             Persons who are not Related Persons, and (ii) with respect to any
             Related Person Transaction or series of related Person Transactions
             (other than any Related Person Transaction described in clause (A)
             (with respect to permitted Restricted Payments by virtue of clauses
             (i), (ii), (iv), (vii), (ix), (x) or (xi) of the proviso contained
             in the definition of "Restricted Payments") (C), (D), (E), (G),
             (J), (K), (L), (M) or (N) of Section 4.10(a)) with an aggregate
             value in excess of $10,000,000, the Company must first obtain a
             favorable written opinion as to the fairness of such transaction to
             the Company or such Subsidiary, as the case may be, from a
             financial point of view, from a nationally recognized investment
             banking or accounting firm; provided that such opinion


                                      -18-
   19



             shall not be necessary if approval of the Board of Directors to
             such Related Person Transaction has been obtained after receipt of
             bona fide bids of at least two other independent parties and such
             Related Person Transaction is in the ordinary course of business.

         Section 1.06.  Section 4.11 of the Original Indenture.  Section 4.11 of
the Original Indenture is hereby amended as follows:

         (a) The first paragraph of Section 4.11 of the Original Indenture is
         hereby amended to read in its entirety as follows:

                  Section 4.11 Limitation on Incurrences of Additional Debt and
             Issuances of Disqualified Capital Stock. Except as set forth in
             this Section 4.11, from and after the Issue Date, the Company shall
             not, and shall not permit TransContinental or any of the Company's
             Subsidiaries to, directly or indirectly, create, incur, assume,
             guarantee, or otherwise become liable for, contingently or
             otherwise (to "Incur" or, as appropriate, an "Incurrence"), any
             Debt or issue any Disqualified Capital Stock, except: (a) Debt
             evidenced by the Notes and the Guarantees in an aggregate amount
             not to exceed $200 million in proceeds to the Company less the
             aggregate amount of proceeds to the Company pursuant to Debt
             incurred under clause (p) below; (b) Debt evidenced by the TARC
             Intercompany Loan and any other Debt at any time owing by any of
             the TARC Entities to TEC in an aggregate outstanding principal
             amount, when added to the then outstanding principal amount of the
             TARC Intercompany Loan and any other Debt incurred pursuant to this
             clause (b) or pursuant to clause (o) below to replace, extend,
             renew or refund Debt incurred pursuant to this clause (b), at any
             one time outstanding not in excess of $920 million less any amount
             repaid pursuant to paragraph (c)(i) of the covenant described
             herein under Section 4.14 hereof; (c) Subordinated Debt of the
             Company solely to any wholly owned Subsidiary of the Company, Debt
             of TCR Holding solely to TransContinental or any wholly owned
             Subsidiary of TCR Holding, Debt or Disqualified Capital Stock of
             TCR Holding to TARC, Debt of any wholly owned Subsidiary of the
             Company solely to the Company or to any wholly owned Subsidiary of
             the Company or Debt of TransContinental or any wholly owned
             Subsidiary of TCR Holding solely to TCR Holding or to any wholly
             owned Subsidiary of TCR Holding; (d) Debt of TransContinental
             outstanding at any time in an aggregate principal amount not to
             exceed the greater of (x) $100 million or (y) the TransContinental
             Borrowing Base, less, in each case, the amount of any Debt of an
             Accounts Receivable Subsidiary (other than Debt owed to the Company
             or TransContinental); (e) Debt in an aggregate principal amount not
             to exceed at any one time $50 million; (f) Debt secured by the
             Storage Assets in an aggregate amount outstanding at any one time
             not to exceed $115 million; (g) Debt secured by a Permitted Lien
             that meets the requirements of clause (c), (g), (m), (o) or (r) of
             the definition of "Permitted Liens," to the extent that such Liens
             would give rise to Debt under clauses (i), (ii), or (iii) of the
             definition of "Debt;" (h) Any guaranty of Debt incurred pursuant to
             clauses (d), (e), (g) or (n) hereof which guaranty shall not be
             included in the determination of the amount of Debt which may be
             Incurred pursuant to (d), (e), (g) or (n) hereof; (i) Swap
             Obligation; (j) Unrestricted Non-Recourse Debt; (k) Debt evidenced
             by the TARC Mortgage Notes; (l) letters of credit and reimbursement
             obligations relating thereto to the extent collateralized by cash
             or Cash Equivalents; (m) Debt evidenced by the TARC Discount Notes;
             (n) Debt of the Company or any of its Subsidiaries


                                      -19-
   20



             or TransContinental owed to TEC which is loaned pursuant to terms
             of the fourth paragraph of either of the covenants contained under
             the headings "-- Excess Cash" and "-- Additional Interest Excess
             Cash Offer" under the TEC Indenture in the aggregate not in excess
             of $50 million; (o) each of the Company, its Subsidiaries and
             TransContinental may Incur Debt as an extension, renewal,
             replacement, or refunding of any item of the Debt permitted to be
             Incurred by clauses (b), (p), (r), (v), (w) or (x) hereof, or this
             clause (o) (each such item of Debt is referred to as "Refinancing
             Debt"), provided, that (1) the maximum principal amount of each
             item of Refinancing Debt (or, if such Refinancing Debt is issued
             with original issue discount, the original issue price of such
             Refinancing Debt) permitted under this clause (o) may not exceed
             the lesser of (x) the principal amount of the item of Debt being
             extended, renewed, replaced, or refunded plus Refinancing Fees or
             (y) if such item of Debt being extended, renewed, replaced, or
             refunded was issued at an original issue discount, the original
             issue price, plus amortization of the original issue discount as of
             the time of the Incurrence of the Refinancing Debt plus Refinancing
             Fees and (2) each item of Refinancing Debt shall rank with respect
             to the Notes to an extent no less favorable in respect thereof to
             the Holders than the related Debt being refinanced; (p) Pari Passu
             Debt or Subordinated Debt of the Company or TCR Holding with
             initial net proceeds to the Company not in excess of $25 million in
             the aggregate less the aggregate amount of proceeds to the Company
             pursuant to Debt incurred under clause (a) above after the Issue
             Date; (q) Debt secured by Liens permitted pursuant to clauses (h)
             and (j) of Permitted Liens, in an aggregate principal amount not to
             exceed $35 million; (r) Debt of TransContinental Incurred in
             connection with the acquisition, construction or improvement of a
             CATOFIN(R) Unit not in excess of 20% of TransContinental's
             Consolidated EBITDA accrued for the period (taken as one accounting
             period) commencing with the first full fiscal quarter that
             commenced after the Phase I Completion Date, to and including the
             fiscal quarter ended immediately prior to the date of such
             calculation, (s) Debt of TARC, TCR Holding or TransContinental with
             an aggregate principal amount outstanding at any one time of up to
             $225 million, (t) Debt of TARC (other than Debt secured by Storage
             Assets in the initial aggregate principal amount of $36 million)
             that is assumed by TCR Holding or TransContinental in connection
             with the Transaction, (u) Debt of TCR Holding with an aggregate
             principal amount outstanding at any one time not in excess of $200
             million, (v) Debt of TCR Holding (other than Debt incurred pursuant
             to clause (s) above) that is assumed by TransContinental in
             connection with the Transaction, (w) Disqualified Capital Stock of
             TCR Holding or TransContinental or unsecured Debt of TCR Holding or
             unsecured or secured Debt of TransContinental, (1) the proceeds of
             which are used to repurchase TEC Notes or (2) that is exchanged for
             TEC Notes, (x) Debt or Disqualified Capital Stock of TCR Holding or
             TransContinental that is used to refinance or replace the TARC
             Intercompany Loan and (y) Debt of the Company, TCR Holding or
             TransContinental owed to TEC that does not in the aggregate exceed
             $50 million principal amount outstanding at any one time.

         (a) The third to last and second to last paragraph of Section 4.11 of
         the Original Indenture is hereby amended to read in its entirety as
         follows:

                  Notwithstanding the foregoing provisions of this covenant, (a)
             the Company, TCR Holding and TransContinental may Incur Senior Debt
             and the Company, TCR Holding and TransContinental may issue
             Disqualified Capital Stock if, at the time such Senior Debt is
             Incurred or such Disqualified Capital Stock is issued, (i) no
             Default or Event of Default


                                      -20-
   21


             shall have occurred and be continuing at the time or immediately
             after giving effect to such transaction on a pro forma basis, and
             (ii) immediately after giving effect to the Consolidated Fixed
             Charges in respect of such Debt being Incurred or such Disqualified
             Capital Stock being issued and the application of the proceeds
             therefrom to the extent used to reduce Debt or Disqualified Capital
             Stock, on a pro forma basis, the Consolidated Fixed Charge Coverage
             Ratio of the entity incurring such Debt for the Reference Period is
             greater than 2.25 to 1, and (b) the Company, TCR Holding and
             TransContinental may Incur Subordinated Debt if, at the time such
             Subordinated Debt is incurred, (i) no Default or Event of Default
             shall have occurred and be continuing at the time or immediately
             after giving effect to such transaction on a pro forma basis, and
             (ii) immediately after giving effect to the Consolidated Fixed
             Charges in respect of such Subordinated Debt being incurred and the
             application of the proceeds therefrom to the extent used to reduce
             Debt, on a pro forma basis, the Consolidated Fixed Charge Coverage
             Ratio of the entity incurring such Debt for the Reference Period is
             greater than 2.0 to 1.

                  Debt Incurred and Disqualified Capital Stock issued by any
             Person that is not a Subsidiary of the Company, TCR Holding or
             TransContinental, as the case may be, which Debt or Disqualified
             Capital Stock is outstanding at the time such Person becomes a
             Subsidiary of, or is merged into, or consolidated with the Company,
             TCR Holding or TransContinental or one of their Subsidiaries, as
             the case may be, shall be deemed to have been Incurred or issued,
             as the case may be, at the time such Person becomes a Subsidiary
             of, or is merged into, or consolidated with the Company, TCR
             Holding or TransContinental, respectively, or one of their
             respective Subsidiaries.

         Section 1.07. Section 4.12 of the Original Indenture. Section 4.12 of
the Original Indenture is hereby amended to read in its entirety as follows:

                  Section 4.12 Limitations on Restricting Subsidiary Dividends.
             The Company shall not, and shall not permit any of its Subsidiaries
             (other than TCR Holding) to, directly or indirectly, create,
             assume, or suffer to exist any consensual encumbrance or
             restriction on the ability of any Subsidiary of the Company (other
             than TCR Holding) to pay dividends or make other distributions on
             the Capital Stock of any Subsidiary of the Company, except
             encumbrances and restrictions existing under this Indenture and any
             agreement of a Person acquired by the Company or a Subsidiary of
             the Company, which restrictions existed at the time of acquisition,
             were not put in place in anticipation of such acquisition and are
             not applicable to any Person or property, other than the Person or
             any property of the Person so acquired. Notwithstanding anything
             contained herein to the contrary, neither the Company nor TCR
             Holding may create an encumbrance or restriction on their ability
             to pay premium, if any, principal of, or interest on, the TARC
             Intercompany Loan.

         Section 1.08. Section 4.13 of the Original Indenture. Section 4.13 of
the Original Indenture is hereby amended to read in its entirety as follows:

                  Section 4.13 Liens. The Company shall not, and shall not
             permit any of its Subsidiaries to, directly or indirectly, Incur,
             or suffer to exist any Lien upon any of its respective property or
             assets, whether now owned or hereafter acquired, other than
             Permitted Liens. Notwithstanding anything in this Indenture to the
             contrary, (i) TARC shall


                                      -21-
   22


             not, directly or indirectly, Incur or suffer to exist any Lien on
             the Capital Stock of TCR Holding owned by it (other than a Lien to
             secure the TARC Intercompany Loan), (ii) TCR Holding may incur a
             Lien on Capital Stock of TransContinental to secure the TARC
             Working Capital Loan and (iii) TransContinental shall not be bound
             by this Section 4.13. For the purpose of determining compliance
             with this Section 4.13, if a Lien meets the criteria of more than
             one of the types of Permitted Liens, the Company or the Subsidiary
             in question shall have the right to determine in its sole
             discretion the category of Permitted Lien to which such Lien
             applies, shall not be required to include such Lien in more than
             one of such categories, and may elect to apportion such Lien
             between or among any two or more categories otherwise applicable.

         Section 1.09. Section 4.14 of the Original Indenture. Section 4.14 of
the Original Indenture is hereby amended to read in its entirety as follows:

                       Section 4.14 Limitation on Asset Sales.  Intentionally
             Omitted.

         Section 1.10. Section 4.18 of the Original Indenture. Section 4.18 of
the Original Indenture is hereby amended to read as follows:

             Section 4.18 Limitations on Line of Business. The Company shall not
             directly or indirectly engage to any substantial extent in any line
             or lines of business activity other than a Related Business and,
             such other business activities as are reasonably related or
             incidental thereto. The Company shall not permit TransContinental
             directly or indirectly to engage to any substantial extent in any
             line or lines of business activity other than a Related Business or
             such other business activities as are reasonably related or
             incidental thereto.

         Section 1.11. Section 4.20 of the Original Indenture. Section 4.20(a)
of the Original Indenture is hereby amended to read as follows:

                  (a) Notwithstanding the provisions of Section 4.3, the Company
             may, and may permit any of its Subsidiaries to, make Investments in
             an Accounts Receivable Subsidiary (i) the proceeds of which are
             applied within five Business Days of the making thereof solely to
             finance the purchase of accounts receivable of the Company and its
             Subsidiaries and (ii) in the form of Accounts Receivable Subsidiary
             Notes to the extent permitted by clause (b) below; provided that
             the aggregate amount of such Investments shall not exceed the
             greater of $20 million or 20% of the TransContinental Borrowing
             Base at any time;

         Section 1.12.  Section 4.23 of the Original Indenture.  Section 4.23 of
the Original Indenture is hereby deleted.

         Section 1.13. Sections 4.23 and 4.24 of the Original Indenture. New
Sections 4.23 and 4.24 are hereby added to the Original Indenture to follow
Section 4.22 to read in their entirety as follows:

                  Section 4.23 Monthly Status Reports. The Company shall cause
             TransContinental to, (A) not later than the 20th day of each month
             (or, if such day is not a Business Day, then the first Business Day
             following such day), commencing in December 1998 and continuing


                                      -22-
   23


             through the Phase II Completion Date, issue a press release (and,
             if applicable, file a copy thereof with the SEC pursuant to a Form
             8-K Current Report) generally disclosing the status of completion
             of the Capital Improvement Program through the end of the
             immediately preceding month and (B) conduct a monthly telephone
             conference call relating thereto with the chief executive officer
             of TARC or his designee in which Holders will be entitled to
             participate and provide notice by press release of the time and
             place of such call at least 48 hours in advance thereof.

                  Section 4.24 Limitation on Issuances of Equity Securities by
             TCR Holding or TransContinental. The Company shall not permit TCR
             Holding, TransContinental or any Subsidiary of either of them to
             issue (other than pursuant to the Transaction, including securities
             issued upon conversion of or in exchange for securities issued
             pursuant to the Transaction upon the terms established in
             connection with the Transaction, or issuances to TransContinental
             or any of its Subsidiaries) any Capital Stock or other equity
             securities (other than Disqualified Capital Stock that is not
             convertible into or exchangeable for Qualified Capital Stock and
             other equity securities that are not accounted for as equity
             securities in accordance with GAAP) unless the issuer first obtains
             a favorable written opinion as to the fairness of such transaction
             to the issuer, from a financial point of view, from an independent
             nationally recognized accounting or investment banking firm.

         Section 1.14. Section 5.1 of the Original Indenture. Section 5.1 of the
Original Indenture is hereby amended to add subsection (d) to read in its
entirety as follows:

                  (d) Notwithstanding anything contained in this Article V to
             the contrary, (i) the provisions of clause (a) shall not apply to
             the transfer by TARC to TCR Holding of the Refinery Assets as part
             of the Transaction, (ii) the provisions of clause (a) shall not
             apply to the transfer to TransContinental by TCR Holding of the
             Refinery Assets as part of the Transaction and (iii) the provisions
             of clauses (a)(2), (a)(3) and (a)(5) shall not apply to a merger of
             TARC with or into TEC.

         Section 1.15. Section 5.2 of the Original Indenture. Section 5.2 of the
Original Indenture is hereby amended to read in its entirety as follows:

                  Section 5.2 Successor Corporation Substituted. Upon any
             consolidation or merger, or any transfer of assets in accordance
             with Section 5.1 (other than the transfers of the Refinery Assets
             by the Company to TCR Holding and by TCR Holding to
             TransContinental pursuant to the Transaction), the Surviving Person
             formed by such consolidation or into which the Company, or a
             Guarantor, as the case may be, is merged or to which such transfer
             is made shall succeed to, and be substituted for, and may exercise
             every right and power of, the Company, or such Guarantor, as the
             case may be, under this Indenture with the same effect as if such
             Surviving Person had been named as the Company, or such Guarantor,
             as the case may be, herein. When a Surviving Person duly assumes
             all of the obligations of the Company pursuant hereto and pursuant
             to the Notes, the predecessor shall be released from such
             obligations.

         Section 1.16. Section 6.1 of the Original Indenture. Section 6.1(d) of
the Original Indenture is hereby amended to read in its entirety as follows:


                                      -23-
   24



                  (d) a default which extends beyond any stated period of grace
             applicable thereto, including any extension thereof, under any
             mortgage, indenture or instrument under which there is outstanding
             any Debt of the Company, any of its Subsidiaries or
             TransContinental with an aggregate principal amount in excess of
             $20,000,000 if by reason of such default the principal of such Debt
             and all accrued and unpaid interest thereon has been declared due
             and payable, or failure to pay such Debt at its stated maturity, if
             either (a) such default results from the failure to pay principal
             of, premium, if any, or interest on any such Debt when due and such
             default continues beyond any applicable cure, forebearance or
             notice period; provided that a waiver by the lenders of such Debt
             of such default shall constitute a waiver hereunder for the same
             period or (b) as a result of such default, the maturity of such
             Debt has been accelerated prior to its scheduled maturity, and such
             default or acceleration continues for a period of 10 days;
             provided, that a rescission or annulment of such default or
             acceleration (prior to any action taken by the Trustee with respect
             to the acceleration of the Obligations under the Notes) pursuant to
             the agreement governing such Debt shall constitute a waiver
             hereunder for the same period.

         Section 1.17. Section 9.1 of the Original Indenture. Section 9.1 of the
Original Indenture is hereby amended to read in its entirety as follows:

                  Section 9.1 Supplemental Indentures Without Consent of
             Holders. Without the consent of any Holder, the Company and the
             Guarantors, if any, when authorized by Board Resolutions, and the
             Trustee, at any time and from time to time, may enter into one or
             more indentures supplemental hereto or a restatement hereof in form
             satisfactory to the Trustee, for any of the following purposes:

                  (a) to cure any ambiguity, defect, or inconsistency, or to
             make any other provisions with respect to matters or questions
             arising under this Indenture which shall not be inconsistent with
             the provisions of this Indenture, provided such action pursuant to
             this clause (a) shall not adversely affect the interests of any
             Holder in any respect;

                  (b) to add to the covenants of the Company for the benefit of
             the Holders or to surrender any right or power herein conferred
             upon the Company or to make any other change that does not
             adversely affect the rights of any Holder, provided that the
             Company has delivered to the Trustee an Opinion of Counsel stating
             that such change does not adversely affect the rights of any
             Holder;

                  (c) to evidence the succession of another Person to the
             Company and the assumption by any such successor of the obligations
             of the Company herein and in the Notes in accordance with Article
             V;

                  (d) to comply with the TIA; or

                  (e) to restate this Indenture so that it reflects this
             Indenture as originally executed as amended by all amendments and
             supplements hereto through the date of such restatement and
             contains only the then effective provisions of this Indenture.



                                      -24-
   25



         Section 1.18. Section 9.6 of the Original Indenture. Section 9.6 of the
Original Indenture is hereby amended to read in its entirety as follows:

                  Section 9.6 Trustee to Sign Amendments, Etc. The Trustee shall
             execute any amendment, supplement, restatement or waiver authorized
             pursuant to this Article IX, provided that the Trustee may, but
             shall not be obligated to, execute any such amendment, supplement,
             restatement or waiver which affects the Trustee's own rights,
             duties or immunities under this Indenture. The Trustee at the
             expense of the Company shall be entitled to receive, and shall be
             fully protected in relying upon, an Opinion of Counsel stating that
             the execution of any amendment, supplement, restatement or waiver
             authorized pursuant to this Article IX is authorized or permitted
             by this Indenture.

         Section 1.19. Article XI of the Original Indenture. Article XI of the
Original Indenture is hereby amended to read in its entirety as follows:

                                   ARTICLE XI

                               RIGHT TO REPURCHASE

                              INTENTIONALLY OMITTED

                                   ARTICLE II
                               GENERAL PROVISIONS

         Section 2.01. Effectiveness of Amendments. This Supplemental Indenture
is effective as of the date first above written. However, the provisions of the
Original Indenture amended or eliminated as provided in this Supplemental
Indenture (the "Amended Provisions") shall remain operative in the form in which
they exist in the Original Indenture until the Transaction Closing Date,
whereupon the Amended Provisions will be amended or eliminated as provided
herein, effective immediately prior to the Transaction Closing Date.

         Section 2.02. Ratification of Indenture. The Original Indenture is in
all respects acknowledged, ratified and confirmed, and shall continue in full
force and effect in accordance with the terms thereof and as supplemented by
this Supplemental Indenture. The Original Indenture and this Supplemental
Indenture, shall be read, taken and construed as one and the same instrument.

         Section 2.03.  Certificate and Opinion as to Conditions Precedent. 
Simultaneously with and as a condition to the execution of this Supplemental
Indenture, the Company is delivering to the Trustee:

                  (a) an Officers' Certificate in the form attached hereto as
Exhibit A; and

                  (b) an Opinion of Counsel covering the matters described in
Exhibit B attached hereto.

         Section 2.04. Effect of Headings. The Article and Section headings in
this Supplemental Indenture are for convenience only and shall not affect the
construction of this Supplemental Indenture.

         Section 2.05.  Governing Law.  THIS SUPPLEMENTAL INDENTURE SHALL BE 
CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF NEW YORK,
AS


                                      -25-
   26



APPLIED TO CONTRACTS MADE AND PERFORMED WITHIN THE STATE OF NEW YORK, WITHOUT
REGARD TO PRINCIPLES OF CONFLICTS OF LAW.

         Section 2.06. Counterparts. This Supplemental Indenture may be executed
in any number if counterparts, each of which so executed shall be deemed to be
an original, but all such counterparts shall together constitute the same
instrument.



                                      -26-
   27



         IN WITNESS WHEREOF, the parties to this Supplemental Indenture have
caused the Supplemental Indenture to be duly executed, and their respective
corporate seals to be hereunto affixed and attached, on and effective as of day
and year first above written.

                                     TRANSAMERICAN REFINING CORPORATION,
                                              A Texas corporation



Attest:                              By:
       ------------------------         -------------------------------------
         Ann F. Gullion,                Name:
         Assistant Secretary            Title:



                                     FIRST UNION NATIONAL BANK,
                                              As Trustee



                                     By:
                                        -------------------------------------
                                        Name:
                                        Title:




                                      -27-