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                                                                  EXHIBIT 4.13


                 INTERCREDITOR AND COLLATERAL AGENCY AGREEMENT

       Intercreditor and Collateral Agency Agreement, dated as of June 13,
1997, by and among Firstar Bank of Minnesota, N.A., in its capacity as
Collateral Agent (as hereinafter defined) and, separately, in it capacity as
TransTexas Note Trustee (as hereinafter defined), Firstar Bank of Minnesota,
N.A., as TEC Note Trustee (as hereinafter defined), TransAmerican Energy
Corporation, a Delaware corporation ("TEC"), as payee of the New Note (as
hereinafter defined), and TransTexas Gas Corporation, a Delaware corporation
(the "Issuer").

                                  WITNESSETH:

              WHEREAS, the Issuer, TransTexas Transmission Corporation, a
Delaware corporation and formerly a Subsidiary of the Issuer ("TTC"), and
American Bank National Association, as Trustee, have entered into an Indenture,
dated as of June 15, 1995, as heretofore amended (as heretofore amended and as
the same may hereafter be amended, modified or supplemented from time to time
in accordance with its terms, the "TransTexas Note Indenture"), pursuant to
which the Issuer has issued its 11 1/2% Senior Secured Notes due 2002 (the
"TransTexas Notes") in the aggregate principal amount of $800,000,000;

              WHEREAS, Firstar Bank of Minnesota, N.A., is the successor by
merger (effective July 12, 1996) to American Bank National Association, and, by
reason thereof, is the successor TransTexas Note Trustee;

              WHEREAS, the Issuer and TTC have entered into certain security
agreements and instruments set forth on Schedule I hereto (as such documents
may be amended, modified or supplemented from time to time, collectively, the
"TransTexas Note Security Documents"), granting a security interest in certain
assets (the "TransTexas Note Collateral") in favor of the TransTexas Note
Trustee for the benefit of the TransTexas Note Holders (as hereinafter
defined);

              WHEREAS, concurrently herewith, the Issuer and TEC are entering
into a Loan Agreement, dated as of the date hereof (as the same may be amended,
modified or supplemented from time to time, the "New Note Loan Agreement"),
pursuant to which the Issuer is issuing its promissory note, bearing interest
at the rate of 10-7/8% per annum, payable to the order of TEC in the principal
amount of $450,000,000, and maturing on June 1, 2002 (the "New Note");

              WHEREAS, the Issuer has entered into certain security agreements
and instruments set forth on Schedule II hereto (as such documents may be
amended, modified or supplemented from time to time, collectively, the "New
Note Security Documents"), granting a security interest in certain assets (the
"New Note Collateral") in favor of and for the benefit of the New Note Holder;
and

              WHEREAS, substantially all of the New Note Collateral is included
in the TransTexas Note Collateral and the Secured Creditors (as hereinafter
defined) desire to set forth their understanding with respect to the Collateral
Agent's duties regarding the New Note Collateral and certain agreements among
the Secured Creditors regarding their interest in the New Note Collateral;

              WHEREAS, concurrently herewith, TEC and the TEC Note Trustee are
entering into a Security and Pledge Agreement, dated as of the date hereof (as
the same may be amended, modified or supplemented from time to time, the "TEC
Pledge Agreement"), pursuant to which the New Note, together with all of TEC's
rights and interests under the New Note Security Documents, will be assigned
and transferred to, and subjected to a security interest in favor of, the TEC
Note Trustee pursuant to the TEC Note Indenture as security for the TEC Notes
for the benefit of the TEC Note Holders;





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       NOW THEREFORE, in consideration for the premises, covenants and
agreements contained herein, the parties hereto agree as follows:

       Section 1.    Definitions.  As used herein, the following terms shall
have the meanings herein specified and all terms used herein and not otherwise
defined herein shall have the meanings provided therefor in the TransTexas Note
Indenture.  Defined terms in this Agreement shall include in the singular
number the plural and in the plural number the singular.

              "Acceleration Notice" shall have the meaning specified in Section
       5(a) hereof.

              "Acceptable Bank" shall mean a bank or trust company in good
       standing and incorporated under the laws of the United States or any
       State thereof or the District of Columbia, with its principal corporate
       trust office within the United States, with capital, surplus and
       undistributed profits of not less than $50,000,000.

              "Agreement" shall mean this Intercreditor and Collateral Agency
       Agreement, as the same may be amended, modified or supplemented from
       time to time.

              "Collateral Agent" shall mean Firstar Bank of Minnesota, N.A., in
       its capacity as Collateral Agent under this Agreement or, upon the
       resignation or removal of Firstar Bank of Minnesota, N.A. as Collateral
       Agent, any successor Collateral Agent appointed pursuant to the
       provisions of Section 9 of this Agreement.

              "Collateral Documents" shall mean, collectively, the TransTexas
       Note Security Documents and the New Note Security Documents.

              "Companies" shall mean TEC, the Issuer and any Guarantor under
       either of the Primary Documents and/or the TEC Note Indenture.

              "Default" shall, with respect to each Primary Document, have the
       meaning provided in such Primary Document.

              "Event of Default" shall, with respect to each Primary Document,
       have the meaning provided in such Primary Document.

              "Holders" shall mean, collectively, the New Note Holder and the
       TransTexas Note Holders.

              "Issuer" shall have the meaning provided in the first paragraph
       hereof.

              "Junior Obligations" shall mean all indebtedness and other
       monetary obligations, including, without limitation, all principal,
       interest, fees, premium, if any, costs and expenses payable, of the
       Companies to the Junior Secured Creditor under the New Note, the New
       Note Loan Agreement, the New Note Security Documents, and any
       instruments, documents or agreements executed by any of the Companies in
       connection therewith.

              "Junior Secured Creditor" shall mean the New Note Holder.

              "New Note" shall have the meaning provided in the fourth recital
       hereof.

              "New Note Collateral" shall have the meaning provided in the
       fifth recital hereof.

              "New Note Holder" shall mean the holder from time to time of the
       New Note, and, until such time as the New Note is released and
       discharged from the TEC Pledge Agreement by instrument in writing
       executed by the TEC Note Trustee, the term "New Note Holder" shall mean
       the TEC Note Trustee.





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              "New Note Loan Agreement" shall have the meaning provided in the
       fourth recital hereof.

              "New Note Security Documents" shall have the meaning provided in
       the fifth recital hereof.

              "Obligations" shall mean, collectively, the Senior Obligations
       and the Junior Obligations.

              "Primary Documents" shall mean, collectively, the TransTexas Note
       Indenture and the New Note Loan Agreement.

              "Pro Rata Share" shall mean, when calculating a Senior Secured
       Creditor's portion of any distribution or amount, that amount (expressed
       as a percentage) equal to a fraction the numerator of which is the then
       outstanding amount of such Senior Secured Creditor's Senior Obligations
       (immediately before such distribution) and the denominator of which is
       the then outstanding amount of all Senior Obligations which are entitled
       to be paid with such distribution pursuant to the terms of this
       Agreement.

              "Required Secured Creditors" shall mean (a) the holders of at
       least 50% in aggregate principal amount of the outstanding Securities or
       (b) the New Note Holder and the TransTexas Note Trustee, on behalf of
       the TransTexas Note Holders.

              "Requisite Holders" shall mean the New Note Holder or the Holders
       of 25% in aggregate principal amount of then outstanding TransTexas
       Notes.

              "Secured Creditors" shall mean, collectively, the Senior Secured
       Creditors and the Junior Secured Creditor.

              "Securities" shall mean, collectively, the New Note and the
       TransTexas Notes.

              "Senior Obligations" shall mean all indebtedness and other
       monetary obligations, including, without limitation, all principal,
       interest, fees, premium, if any, costs and expenses payable, of the
       Companies to the Senior Secured Creditor under the TransTexas Notes, the
       TransTexas Note Indenture, the TransTexas Note Security Documents, and
       any instruments, documents or agreements executed by any of the
       Companies in connection therewith.

              "Senior Secured Creditors" shall mean the TransTexas Note
       Trustee, together with the TransTexas Note Holders.

              "Shared Collateral" means Collateral that is subject to the liens
       and security interests of any one or more of the New Note Security
       Documents and the liens and security interests of any one or more of the
       TransTexas Note Security Documents.

              "TEC Notes" shall mean, collectively, the $475,000,000 aggregate
       principal amount of 11 1/2% Senior Secured Notes due 2002 and the
       $1,130,000,000 aggregate principal amount of 13% Senior Secured Discount
       Notes due 2002, issued by TEC pursuant to the TEC Note Indenture.

              "TEC Note Holders" shall mean, collectively, the holders from
       time to time of the TEC Notes.

              "TEC Note Indenture" shall mean the Indenture, dated as of June
       13, 1997, between TEC and the TEC Note Trustee, pursuant to which TEC
       has issued the TEC Notes.

              "TEC Note Pledge Agreement" shall have the meaning provided in
       the seventh recital hereof.

              "TEC Note Trustee" shall mean Firstar Bank of Minnesota, N.A., in
       its capacity as Trustee under the TEC





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       Note Indenture or, upon the resignation or removal of Firstar Bank of
       Minnesota, N.A., as TEC Note Trustee, any successor Trustee appointed
       pursuant to the provisions of Article VII of the TEC Note Indenture.

              "TransTexas Note Collateral" shall have the meaning provided in
       the third recital hereof.

              "TransTexas Note Holders" shall mean, collectively, the holders
       from time to time of the TransTexas Notes.

              "TransTexas Note Indenture" shall have the meaning provided in
       the first recital hereof.

              "TransTexas Note Security Documents" shall have the meaning
       provided in the third recital hereof.

              "TransTexas Note Trustee" shall mean Firstar Bank of Minnesota,
       N.A., in its capacity as Trustee under the TransTexas Note Indenture or,
       upon its resignation or removal as TransTexas Note Trustee, any
       successor Trustee appointed pursuant to the provisions of Section 7.8 of
       the TransTexas Note Indenture.

              "TransTexas Notes" shall have the meaning provided in the first
       recital hereof.

              "Trustees" shall mean the New Note Holder and the TransTexas Note
       Trustee.

       Section 2.    Appointment.  TEC, as payee of the New Note, the TEC Note
Trustee, for the benefit of the TEC Note Holders, and the TransTexas Note
Trustee, for the benefit of the TransTexas Note Holders, hereby jointly
designate and appoint the Collateral Agent, and the Collateral Agent hereby
accepts such appointment, to act as collateral agent and representative of the
New Note Holder, for the benefit of the TEC Note Holders, and the TransTexas
Note Trustee, for the benefit of the TransTexas Note Holders, in the manner and
upon the terms and conditions set forth herein.  Subject to Sections 11, 12(a)
and 13, from and after the date hereof, any New Note Collateral in the
possession of either of the Trustees (or any of its agents) shall be held by
such Trustee (or agent) as an agent and representative of the Collateral Agent
hereunder.  Concurrently with the execution of this Agreement, or as soon as
practicable thereafter, each of the Trustees shall deliver any and all New Note
Collateral in its possession (or the possession of any of its agents), as of
the date hereof or at any time thereafter, to the Collateral Agent, who shall
hold such New Note Collateral on behalf of the Trustees for the benefit of the
Holders with notice of their respective security interests therein.  TEC and
the TEC Note Trustee, on behalf of the New Note Holder, and the TransTexas Note
Trustee, on behalf of the TransTexas Note Holders, each hereby irrevocably
authorizes, and each Secured Creditor, by its acceptance of any Security, shall
be deemed irrevocably to have authorized, the Collateral Agent to (a) take such
action on behalf of the New Note Holder and on behalf of the TransTexas Note
Trustee, for the benefit of the TransTexas Note Holders, under the provisions
of this Agreement and any of the Collateral Documents and to exercise such
powers and to perform such duties hereunder and thereunder as are specifically
delegated to or required of the Collateral Agent by the terms hereof and
thereof and such other powers as are reasonably incidental thereto, and (b)
exercise, on behalf of the New Note Holder and on behalf of the TransTexas Note
Trustee, for the benefit of the TransTexas Note Holders, all remedies available
to the Trustees under the Collateral Documents, including, without limitation,
the right to foreclose or otherwise realize upon any of the New Note Collateral
and to initiate, prosecute and defend any and all legal proceedings against the
Companies or any other party to any Collateral Document to the extent that such
legal proceedings relate to or affect the New Note Collateral or the interests
of the Secured Creditors.  The Collateral Agent may perform any of its duties
hereunder by or through its agents or employees.

       Section 3.    Nature of Duties.  The Collateral Agent shall have no
duties or responsibilities except those expressly set forth or described herein
or in the Collateral Documents.  Neither the Collateral Agent nor any of its
officers, directors, employees or agents shall be liable for any claims,
losses, damages, penalties, actions, judgments, suits, liabilities,
obligations, costs or expenses of any kind or nature whatsoever resulting from
any action taken or omitted by it as such hereunder or under any Collateral
Document or in connection herewith or therewith, unless caused by its or their
gross negligence, bad faith or willful misconduct.  The Collateral Agent shall
not have, by reason of this Agreement or any Collateral Document, a fiduciary
relationship in respect of any Secured Creditor,





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and nothing in this Agreement or any Collateral Document, expressed or implied,
is intended to or shall be so construed as to impose upon the Collateral Agent
any obligations in respect of any Collateral Document except as expressly set
forth herein.

       Section 4.    Lack of Reliance on the Collateral Agent.  The Collateral
Agent shall have no duty or responsibility, either initially or on a continuing
basis, to provide any Trustee or Secured Creditor with any credit or other
information with respect to any of the Companies, whether currently in its
possession or coming into its possession at any time or times hereafter, except
to the extent specifically provided in this Agreement.

       Section 5.    Exercise of Remedies under Collateral Documents.

       (a) Trustee's Notices.  If either Trustee has notice of a Default or
Event of Default, such Trustee shall give notice to the other Trustee and to
the Collateral Agent within three Business Days after such notice of Default or
Event of Default.  If a Trustee or the Requisite Holders by notice to the
Issuer declare all unpaid principal and accrued interest to the date of
acceleration on the New Note or the TransTexas Notes then outstanding to be due
and payable, or if such principal and interest ipso facto becomes due and
payable pursuant to Section 8.1(e) or Section 8.1(f) of the New Note Loan
Agreement or Section 6.2 of the TransTexas Note Indenture, the New Note Holder,
if the New Note becomes due and payable, or the TransTexas Note Trustee, if the
TransTexas Notes become due and payable, shall give notice to the Collateral
Agent and the other Trustee of such acceleration (an "Acceleration Notice")
within three Business Days after such acceleration.  Upon receipt by the
Collateral Agent of an Acceleration Notice or upon receipt by the Collateral
Agent of notice of an Event of Default under the TransTexas Note Indenture or
the New Note Loan Agreement, together with instructions from the Required
Secured Creditors as to the actions to be taken by the Collateral Agent, the
Collateral Agent shall, within three Business Days after receipt of such notice
and instructions, commence the taking of such actions toward collection or
enforcement of any Collateral Document and the New Note Collateral (or any
portion thereof), including, without limitation, action toward foreclosure upon
any New Note Collateral, as instructed by the Required Secured Creditors.  If
any Default or Event of Default which was the basis for the giving of a notice
to the Collateral Agent shall be cured or waived, and, in the case where there
has been an acceleration, rescission of such acceleration has occurred, in
accordance with the terms of the TransTexas Note Indenture or the New Note Loan
Agreement, any direction to the Collateral Agent to take any action in
connection with such notice shall be deemed rescinded upon notification by the
TransTexas Note Trustee or the New Note Holder given to the Collateral Agent of
such cure or waiver and rescission of acceleration, if applicable.

       (b)    Duty to Instruct.  If the Obligations under one of the TransTexas
Note Indenture or the New Note Loan Agreement have been accelerated or an Event
of Default has occurred or is continuing under the TransTexas Note Indenture or
New Note Loan Agreement and the TransTexas Note Trustee or the New Note Holder,
as applicable, has notice thereof, such Trustee shall send written notice
thereof to the Collateral Agent and shall instruct the Collateral Agent as to
the actions, if any, toward foreclosure on the New Note Collateral that such
Trustee deems appropriate in its discretion.

       (c)    Rights of Collateral Agent.

              (i)    Right to Rely.  The Collateral Agent may rely on any
       document reasonably believed by it to be genuine and to have been signed
       or presented by the proper person.  The Collateral Agent need not
       investigate any fact or matter stated in any such document.  Before the
       Collateral Agent acts or refrains from acting it may consult with
       counsel and may require an Officers' Certificate or an Opinion of
       Counsel, which shall conform to Section 14.4 or 14.5 (as the case may
       be) of the TransTexas Note Indenture.  The Collateral Agent shall not be
       liable for any action it takes or omits to take in good faith in
       reliance on any such certificate or opinion.

              (ii)   Attorneys/Agents.  The Collateral Agent may act through
       its attorneys and agents and shall not be responsible for the misconduct
       or negligence of any agent appointed with due care.





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              (iii)  Good Faith Belief in Authority, Rights or Powers.  The
       Collateral Agent shall not be liable for any action it takes or omits to
       take in the good faith belief that such act or omission was authorized
       or within its rights or powers.

              (iv)   No Investigation.  The Collateral Agent shall not be bound
       to make any investigation into the facts or matters stated in any
       resolution, certificate, statement, instrument, opinion, notice,
       request, direction, consent, order, bond, debenture or other paper or
       document, but the Collateral Agent, in its discretion, may make such
       further inquiry or investigation into such facts or matters as it may
       see fit.

              (v)    Obligation to Act upon Instructions.  The Collateral Agent
       shall be under no obligation to exercise any of the rights or powers
       vested in it by this Agreement and/or any Collateral Document at the
       request, order or direction of any of the Secured Creditors, pursuant to
       the provisions of this Agreement and/or the TransTexas Note Indenture or
       the New Note Loan Agreement or any Collateral Document, unless such
       Secured Creditors shall have offered to the Collateral Agent reasonable
       security or indemnity against the costs, expenses and liabilities which
       may be incurred therein or thereby.  Upon receipt of such reasonable
       security or indemnity, however, the Collateral Agent shall act upon the
       instructions of the Required Secured Creditors.  Notwithstanding the
       foregoing, the Collateral Agent shall not take or refrain from taking
       such action if so taking or refraining from taking such action, as the
       case may be, would violate applicable law or the terms of the Collateral
       Documents or the Primary Documents.

              (vi)   Requests for Instructions.  If the Collateral Agent shall
       request instructions from the Secured Creditors with respect to any act
       or action (including failure to act) in connection with this Agreement
       or any Collateral Document, the Collateral Agent shall be entitled to
       refrain from such act or taking such action unless and until the
       Collateral Agent shall have received instructions from the Required
       Secured Creditors, and the Collateral Agent shall not incur liability to
       any person by reason of so refraining.  Without limiting the foregoing,
       no Secured Creditor shall have any right of action whatsoever against
       the Collateral Agent as a result of the Collateral Agent acting or
       refraining from acting hereunder or under any Collateral Document in
       accordance with the instructions of the Required Secured Creditors in
       accordance with this Agreement and the Collateral Documents.
       Notwithstanding the foregoing, the Collateral Agent may not refuse to
       perform the duties expressly required of it by the terms of this
       Agreement.

       Section 6.    Compensation and Indemnification.

       (a)    Compensation and Expenses.  The Companies agree, jointly and
severally, to pay to the Collateral Agent from time to time upon demand,
reasonable compensation for the services of the Collateral Agent hereunder and
all reasonable fees, out-of-pocket costs and expenses of the Collateral Agent
(including, without limitation, the reasonable fees and disbursements of
counsel) (A) arising in connection with the preparation, execution, delivery,
modification and termination of this Agreement or the enforcement of any of the
provisions hereof or of any Collateral Document, or (B) incurred or required to
be advanced in connection with the sale or other disposition of any New Note
Collateral pursuant to any Collateral Document and the preservation, protection
or defense of the Collateral Agent's rights hereunder and/or under the
Collateral Documents and in and to the New Note Collateral.

       (b)    Stamp and Other Taxes.  The Companies hereby agree, jointly and
severally, to the extent permitted by applicable law, to indemnify the
Collateral Agent, each Trustee and each Secured Creditor for, and hold each of
them harmless against, any present or future claim for liability for any stamp
or other similar tax and any penalties or interest with respect thereto, which
may be assessed, levied or collected by any jurisdiction in connection with any
Collateral Document or any New Note Collateral (other than taxes on the income
of the Collateral Agent or franchise taxes imposed on the Collateral Agent).

       (c)    Filing Fees, Excise Taxes, Etc.  The Companies hereby agree,
jointly and severally, to the extent permitted by applicable law, to pay or to
reimburse the Collateral Agent for any and all amounts in respect of all
search, filing, recording and registration fees, taxes, excise taxes and other
similar imposts which may be payable or determined to be payable in respect of
the execution, delivery, performance and enforcement of this Agreement





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or any Collateral Document (other than taxes on the income of the Collateral
Agent or franchise taxes imposed on the Collateral Agent).

       (d)    Indemnification of Collateral Agent.  The Companies shall,
jointly and severally, indemnify the Collateral Agent for, and hold it harmless
against, any and all claims, demands, expenses (including, but not limited to,
reasonable compensation, disbursements and expenses of the Collateral Agent's
agents and counsel), losses or liabilities incurred by it without negligence,
bad faith or willful misconduct on its part in any way arising out of or in
connection with the acceptance and administration of this Agreement and its
rights or duties hereunder or under any Collateral Document.  The Collateral
Agent shall notify the Companies promptly of any claim asserted against the
Collateral Agent for which it may seek indemnity.  The Companies shall defend
any such claim and the Collateral Agent shall provide reasonable cooperation at
the Companies' expense in such defense.  The Collateral Agent may have separate
counsel and the Companies shall pay the reasonable fees and expenses of such
counsel; provided, that the Companies will not be required to pay such fees and
out-of-pocket expenses if it assumes the Collateral Agent's defense and
provides the Collateral Agent with an Opinion of Counsel that there is no
conflict of interest between the Companies and the Collateral Agent in
connection with such defense.  The Companies need not pay for any settlement
made without its written consent.  The Companies need not reimburse any expense
or indemnify against any loss or liability to the extent incurred by the
Collateral Agent through its negligence, bad faith or willful misconduct.  When
the Collateral Agent incurs expenses or renders services after an Event of
Default specified in Section 6.1(e) or (f) of the TransTexas Note Indenture
occurs, such expenses and the compensation for such services are intended to
constitute expenses of administration under any Bankruptcy Law.

       (e)    Survival of Obligations.  All obligations set forth in this
Section 6 shall survive the execution, delivery and termination of this
Agreement and the other Collateral Documents and the payment of all other
Obligations.

       (f)    Lien on Shared Collateral.  To secure the obligations of the
Companies set forth in this Section 6, the Collateral Agent shall have a Lien
pari passu with that of the TransTexas Note Trustee, in the case in which there
are any Senior Obligations outstanding under the TransTexas Note Indenture, or
a lien prior to that of the New Note Holder, in the case in which there are no
Obligations outstanding under the TransTexas Note Indenture, but there are any
Obligations outstanding under the New Note Loan Agreement, on all New Note
Collateral held or collected by the Collateral Agent in its capacity as such.

       Section 7.    Collateral Agent's Dealings with the Companies.  The
Collateral Agent may accept deposits from, lend money to, or generally engage
in any kind of banking, trust or other business with the Companies or any of
their Affiliates, in each case, as if it were not the Collateral Agent
hereunder.

       Section 8.    Holders.  The Collateral Agent may deem and treat the TEC
Note Trustee as the Holder of the New Note for all purposes hereunder, and the
TEC Note Trustee shall be deemed to be the registered owner of the New Note for
all purposes hereunder.  The Collateral Agent may deem and treat the registered
owner of any of the Securities as the owner thereof for all purposes hereunder.
Any request, authority or consent of any person or entity who, at the time of
making such request or giving such authority or consent, is the registered
owner of any Security, shall be conclusive and binding upon any subsequent
holder, transferee, assignee or endorsee, as the case may be, of such Security
or any security issued in exchange therefor.  Upon the written or telephonic
request of the Collateral Agent, the TransTexas Note Trustee agrees to furnish
to the Collateral Agent a list of the registered owners of all Securities
issued under the TransTexas Note Indenture and the outstanding principal amount
of each and all such Securities within 10 Business Days after any request
therefor from the Collateral Agent, and the New Note Holder shall also notify
the Collateral Agent as to the outstanding balance of the New Note.  The
Collateral Agent shall be entitled to rely on such information as being
accurate and complete.

       Section 9.    Resignation by or Removal of the Collateral Agent.

       (a)    Resignation; Removal.  The Collateral Agent may resign from the
performance of all of its functions and duties hereunder by giving 20 Business
Days' prior written notice to the Companies and the Trustees.





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The Required Secured Creditors may, at any time, remove the Collateral Agent by
giving 20 Business Days' prior written notice to the Companies, the Trustees
and the Collateral Agent.  Such resignation or removal shall take effect upon
the appointment of a successor Collateral Agent pursuant to paragraph (b) or
(c) below or as otherwise provided below.

       (b)    Appointment of Successor.  Upon any such notice of resignation or
removal, the Required Secured Creditors shall appoint a successor Collateral
Agent hereunder who shall be an Acceptable Bank.  If a successor Collateral
Agent shall not have been so appointed within the period specified in Section
9(a), the Collateral Agent, with the consent of the Companies, shall then
appoint a successor Collateral Agent which shall serve as Collateral Agent
hereunder until such time, if any, as the Required Secured Creditors appoint a
successor Collateral Agent as provided above.

       (c)    Effectiveness of Resignation or Removal.  A successor Collateral
Agent shall deliver a written acceptance of its appointment to the retiring
Collateral Agent and to the Companies.  Immediately thereafter, the retiring
Collateral Agent shall transfer all property held by it as Collateral Agent to
the successor Collateral Agent, subject to the Lien provided in Section 6(f),
and shall execute and deliver to the successor Collateral Agent such documents
as are necessary to perfect or maintain the security interests of the Trustees
in the New Note Collateral, including any documents necessary to assign or
transfer all interests of the retiring Collateral Agent in the New Note
Collateral to the successor Collateral Agent, in the form or forms adequate for
proper filing or recording in such offices and such jurisdictions as are
necessary to put the successor Collateral Agent in the same position as was the
retiring Collateral Agent with respect to the New Note Collateral.  Thereafter,
the resignation or removal of the retiring Collateral Agent shall become
effective and the successor Collateral Agent shall have all the rights, powers
and duties of the Collateral Agent under this Agreement.  A successor
Collateral Agent shall give notice of its succession to each Secured Creditor.

       (d)    Consolidation, Merger, Etc.  If the Collateral Agent consolidates
with, merges or converts into, or transfers all or substantially all of its
corporate trust business to, another corporation, the resulting, surviving or
transferee corporation without any further act shall, if such resulting,
surviving or transferee corporation is an Acceptable Bank, be the successor
Collateral Agent.  The transferring, merging or converting Collateral Agent
shall have all documents necessary to perfect or maintain the security interest
of the Trustees in the New Note Collateral, including any documents necessary
to assign or transfer all interests of the transferring, merging or converting
Collateral Agent in the New Note Collateral, executed and delivered to it in
the form or forms adequate for proper filing or recording in such offices and
such jurisdictions as are necessary to put the successor Collateral Agent in
the same position as the transferring, merging or converting Collateral Agent
with respect to the New Note Collateral.

       (e)    Compensation Continuing.  Any person or entity acting as
Collateral Agent shall continue to be entitled to receive compensation as
provided in Section 6 hereof so long as such person or entity acts as
Collateral Agent hereunder.

       Section 10.   Release or Substitution of New Note Collateral.  The
Collateral Agent shall, at any time and from time to time, release or
substitute all or any portion of the New Note Collateral in accordance with and
upon receipt of written instructions from the Required Secured Creditors.  The
Secured Creditors agree that each such release or substitution shall be binding
and conclusive upon them and hereby waive all rights and claims with respect to
such release or substitution.

       Section 11.   First and Prior Rights of Senior Secured Creditors; Second
Rights of Junior Secured Creditor.

       (a)    As long as all or any portion of the Senior Obligations remains
outstanding, unpaid or unsatisfied, each of the Junior Secured Creditor agrees
that (i) except as expressly set forth in this Section 11(a), the Junior
Obligations shall be and hereby are subordinated and the payment thereof is
deferred until the full and final payment in cash of the Senior Obligations,
(ii) its interest in the New Note Collateral shall, irrespective of the time,
order or method of perfection or creation of any security interests or liens in
the New Note Collateral on behalf of any





                                       8
<PAGE>   9
Secured Creditor, or the recording of mortgages or filing of financing
statements or any other recordings or filings, be junior and subordinated, and
inferior in priority, operation and effect, to the interests of the Senior
Secured Creditors in the New Note Collateral to the extent and in the manner
provided herein, and (iii) it shall refrain from taking any action to foreclose
upon, take possession of, liquidate or otherwise proceed against the New Note
Collateral, whether under the New Note Security Documents or otherwise, except
as expressly set forth herein.  Notwithstanding the preceding provisions of
this Section 11(a), the Companies shall be permitted to pay, and the Junior
Secured Creditor shall be permitted to receive, any regularly scheduled payment
of interest or principal on the New Note so long as at the time of such
payment, or after giving effect thereto, no Default or Event of Default shall
have occurred and be continuing under the TransTexas Note Indenture or would
occur thereunder after giving effect to such payment.

       (b)  The Junior Secured Creditor will hold in trust and immediately pay
over to the TransTexas Note Trustee, in the same form of payment received, with
appropriate endorsements, for application to the Senior Obligations, any cash
amount that any of the Companies pays to the Junior Secured Creditor with
respect to the New Note, or, as collateral for the Senior Obligations, any
other assets of any of the Companies that the Junior Secured Creditor may
receive with respect to the Junior Obligations, in each case, except with
respect to payments expressly permitted pursuant to Section 11(a).

       Section 12.   Bankruptcy, Etc.

       (a)    At any meeting of creditors of the Issuer or in the event of any
case or proceeding, voluntary or involuntary, for the distribution, division or
application of all or part of the assets of the Issuer or the proceeds thereof,
whether such case or proceeding is for the liquidation, dissolution or winding
up of the Issuer or its business, a receivership, insolvency or bankruptcy case
or proceeding, an assignment for the benefit of creditors or a proceeding by or
against the Issuer for relief under the Bankruptcy Law, the Collateral Agent is
hereby irrevocably authorized at any such meeting or in any such proceeding to
receive or collect any cash or other assets of the Issuer distributed, divided
or applied by way of dividend or payment, or any securities issued on account
of any Junior Obligation, and turn over such cash or such other assets or
securities to the TransTexas Note Trustee as collateral for the Senior
Obligations, and to have applied to the Senior Obligations any cash proceeds of
any realization upon such other assets or securities until all of the Senior
Obligations shall have been paid in full in cash, rendering to the Junior
Secured Creditor any surplus to which such Junior Secured Creditor are then
entitled.

       (b)  At any such meeting of creditors or in the event of any such case
or proceeding, the Junior Secured Creditor shall retain the right to vote and
otherwise act with respect to the Junior Obligations (including, without
limitation, the right to vote to accept or reject any plan of partial or
complete liquidation, reorganization, arrangement, composition or extension),
provided, that the Junior Secured Creditor shall not vote with respect to any
such plan or take any other action in any way so as to contest (i) the validity
of any Senior Obligation or any TransTexas Note Collateral therefor or
guaranties thereof, (ii) the relative rights and duties of any TransTexas Note
Holder established in any instruments or agreements creating or evidencing any
of the Senior Obligations with respect to any of such New Note Collateral or
guaranties or (iii) the Junior Secured Creditor's obligations and agreements
set forth in this Agreement.

       Section 13.   Application of Payments Received from Realization on the
New Note Collateral.

       (a) Upon the occurrence of any event described in Section 12, all monies
received by the Collateral Agent from the sale, liquidation or otherwise of the
New Note Collateral shall be distributed as provided below:

              (i)    first, to pay the reasonable costs and expenses of the
       Collateral Agent in obtaining such proceeds;

              (ii)   to the extent proceeds remain after the distribution
       pursuant to clause (i) above, an amount equal to the outstanding Senior
       Obligations held by the Senior Secured Creditors shall be paid to such
       Senior Secured Creditors, with each Senior Secured Creditor receiving an
       amount equal to its outstanding





                                       9
<PAGE>   10
       Senior Obligations or, if the proceeds are insufficient for the payment
       in full of all Senior Obligations held by the Senior Secured Creditors,
       its Pro Rata Share of the amount available to be distributed pursuant to
       this clause (ii);

              (iii)  to the extent proceeds remain after the applications
       required by clauses (i) and (ii) above, such proceeds shall be paid to
       the New Note Holder for application to the Junior Obligations; and

              (iv)   to the extent proceeds remain after the applications
       required by clauses (i), (ii) and (iii) above, such proceeds shall be
       paid to the Issuer or its successors or assigns.

       (b)    Except upon the occurrence of any event described in Section 12,
all monies received by the Collateral Agent from the sale, liquidation or
otherwise of the New Note Collateral shall be applied, (i) if no Event of
Default under the TransTexas Note Indenture shall have occurred and be
continuing or shall result thereunder from the payment of the Junior
Obligations, to the payment of the Obligations so as not to impair or affect
the right of the TransTexas Note Holders to receive payments on the Senior
Obligations as and when due, and (ii) to the payment of the Senior Obligations
if an Event of Default under the TransTexas Note Indenture shall have occurred
and be continuing or shall result thereunder from the payment of the Junior
Obligations.  Notwithstanding anything to the contrary in this Section 13(b),
at all times other than during periods in which an Event of Default shall have
occurred and is continuing, the Collateral Agent may release Collateral to one
or more of the Companies from time to time as permitted in the Primary
Documents.

       (c)    Nothing contained in this Agreement shall or shall be construed
to prohibit, limit or otherwise affect the rights of the Issuer to transfer,
dispose of or otherwise deal with its properties and assets included within the
New Note Collateral, and the proceeds thereof, in any manner permitted under
the Primary Documents.

       (d)    Nothing contained in this Agreement shall or shall be construed
to impair or affect the right of the TransTexas Note Holders to receive
payments of principal of and interest on the TransTexas Notes as and when due
or the right of the Holder of any TransTexas Note to institute suit for the
enforcement of any payment thereon as and when due.

       Section 14.   Further Assurances.  Each party hereto covenants to
execute and deliver such further instruments and to take such further action as
the Collateral Agent or the Required Secured Creditors may at any time or times
reasonably request in order to carry out the provisions and intent of this
Agreement.

       Section 15.   Notices.  Any notice or other communication in connection
with this Agreement shall be effective if made in writing, addressed to such
party at its address set forth opposite its signature below, and delivered or
mailed postage prepaid, or at such other addresses as the addressee shall have
specified by notice given in compliance with this Section 15.  All notices to
any Holder shall be given by delivering or mailing such notice to the New Note
Holder or the TransTexas Note Trustee, as the case may be.  Notices shall be
deemed given upon the earlier to occur of (i) the third day following deposit
thereof in the U.S. Mail, first class postage prepaid, or (ii) receipt by the
party to whom such notice is directed.

       Section 16.   Benefit of Agreement; Obligations Several.  This Agreement
shall be binding upon and inure to the benefit of and be enforceable by the
respective heirs, administrators, successors and assigns of the parties hereto.
The obligations of each of the parties to this Agreement are several and not
joint, it being expressly agreed that no Trustee shall be liable for the
failure of any other Trustee to perform its obligations hereunder.  Each
Secured Creditor, including without limitation, each Holder by its acceptance
of a Security, hereby consents to and agrees to be bound by the provisions
hereof applicable to such Secured Creditor.

       Section 17.   Governing Law.  This Agreement and the rights and
obligations of the parties hereunder shall be construed in accordance with and
be governed by the laws of the State of New York.  Any legal action or
proceeding with respect to this Agreement may be brought in courts of the State
of New York or of the United States of America for the Southern District of New
York and, by execution and delivery of this Agreement, each party





                                       10
<PAGE>   11
hereto hereby accepts for itself and in respect of its property, generally and
unconditionally, the non-exclusive jurisdiction of the aforesaid courts.

       Section 18.   Counterparts.  This Agreement may be executed in any
number of counterparts and by the different parties hereto on separate
counterparts, each of which when so executed and delivered shall be an
original, but all of which shall together constitute one and the same
instrument.  A complete set of counterparts shall be lodged with the Collateral
Agent.

       Section 19.   Effectiveness.  This Agreement shall become effective on
the date on which all of the parties hereto shall have signed a copy hereof
(whether the same or different copies) and shall have delivered the same to the
Collateral Agent at its address set forth opposite its signature below.  This
Agreement shall remain effective until all of the Senior Obligations are
irrevocably paid in full (or deemed to have been paid and discharged pursuant
to Article Eight of the TransTexas Note Indenture), provided, that once the
Obligations owed to any Secured Creditor shall have been irrevocably paid in
full and its rights and obligations under the Primary Documents, as the case
may be, have been terminated, such Secured Creditor shall have no further
rights or obligations hereunder.

       Section 20.   Headings Descriptive.  The headings of the several
sections of this Agreement are inserted for convenience only and shall not in
any way affect the meaning or construction of any provision of this Agreement.

       Section 21.   Amendment or Waiver.  This Agreement may be amended,
changed, waived or terminated with the written consent of the Required Secured
Creditors, provided, that such amendment, waiver, modification or termination
shall not impair or affect the right of the TransTexas Note Holders to receive
payments of principal of and interest on the TransTexas Notes as and when due
or the right of the Holder of any TransTexas Note to institute suit for the
enforcement of any payment thereon as and when due; and provided further, that
the provisions of Sections 11, 12 and 13 shall not be amended, changed, waived,
or terminated without the prior written consent of the majority of holders of
the outstanding principal amount of the Senior Obligations, provided, however,
that no such consent of any Secured Creditor shall be required if the
Obligations to such Secured Creditor shall have been irrevocably paid in full
and are no longer outstanding.

       Section 22.   Survival.  All indemnities set forth herein shall survive
the execution and delivery of this Agreement and the repayment of all
Obligations.

       Section 23.   Inconsistent Provisions.  If any provision of this
Agreement shall be inconsistent with, or contrary to, any provision in any
Collateral Document, the provision in this Agreement shall be controlling, and
shall supersede such inconsistent provision to the extent necessary to give
full effect to all provisions contained in this Agreement.

       Section 24.   Shared Collateral.  Notwithstanding anything to the
contrary contained in the New Note Security Documents or the TransTexas Note
Security Documents, Shared Collateral in the possession of the Collateral Agent
pursuant to this Agreement, in the possession of TEC or the TEC Note Trustee
pursuant to any of the New Note Security Documents, or in the possession of the
TransTexas Note Trustee pursuant to any of the TransTexas Note Security
Documents shall, pursuant to Section 9-305 of the Uniform Commercial Code as in
effect in the State of New York, be held by such party in possession for its
own account to the extent of its interest therein, and as pledgeholder and
bailee for each of the other Secured Creditors, so that each of the Secured
Creditors shall be deemed to have possession of such Shared Collateral.  Each
Secured Creditor is authorized and directed by the Issuer to deliver to the
Collateral Agent for the benefit of the Secured Creditors pursuant to this
Agreement any Shared Collateral now or hereafter in the possession of such
Secured Creditor, and none of such Shared Collateral shall be released or
distributed to the Issuer without the prior written consent of the TEC Note
Trustee, on behalf of the Junior Secured Creditor, and the TransTexas Note
Trustee, on behalf of the Senior Secured Creditors.





                                       11
<PAGE>   12
       IN WITNESS WHEREOF, the Collateral Agent, the Trustees and the Companies
have caused this Agreement to be duly executed as of the day and year first
above written.

                            COLLATERAL AGENT
                            ----------------

                            FIRSTAR BANK OF MINNESOTA, N.A., as Collateral
                            Agent


                            By:  /s/ FRANK P. LESLIE, III
                                ------------------------------------------------
                            Name: Frank P. Leslie, III
                            Title: Vice President


                            TRANSTEXAS NOTE TRUSTEE
                            -----------------------

                            FIRSTAR BANK OF MINNESOTA, N.A., as TransTexas Note
                            Trustee


                            By:  /s/ FRANK P. LESLIE, III
                                ------------------------------------------------
                            Name: Frank P. Leslie, III
                            Title: Vice President


                            TEC NOTE TRUSTEE
                            ----------------

                            FIRSTAR BANK OF MINNESOTA, N.A., as TEC Note
                            Trustee


                            By:  /s/ FRANK P. LESLIE, III
                                ------------------------------------------------
                            Name: Frank P. Leslie, III
                            Title: Vice President


                            COMPANIES
                            ---------

                            TRANSAMERICAN ENERGY CORPORATION


                            By:  /s/ ED DONAHUE
                                ------------------------------------------------
                            Name: Ed Donahue
                            Title: Vice President


                            TRANSTEXAS GAS CORPORATION


                            By:  /s/ ED DONAHUE
                                ------------------------------------------------
                            Name: Ed Donahue
                            Title: Vice President





                                       12
<PAGE>   13
                                   Schedule I

                       TransTexas Note Security Documents


      1.      Mortgage, Deed of Trust, Assignment of Production, Security
Agreement and Financing Statement dated June 18, 1995, executed by TransTexas
Gas Corporation ("TTGC"), as Mortgagor, to James A. Taylor, trustee for the
benefit of American Bank National Association as Indenture Trustee (the
"Trustee").

       2.     First Amendment and Supplement to Mortgage Deed of Trust,
Assignment of Production, Security Agreement and Financing Statement dated as
of June 20, 1995, executed by TTGC, as Mortgagor, for the benefit of the
Trustee.

       3.     Amendment to Mortgage, Deed of Trust, Assignment of Production,
Security Agreement and Financing Statement dated October 16, 1995, executed by
TTGC, as Mortgagor, for the benefit of the Trustee.

       4.     Mortgage, Deed of Trust, Assignment of Production, Security
Agreement and Financing Statement dated June 6, 1996, executed by TTGC, as
Mortgagor, to James A. Taylor, trustee for the benefit of the Trustee.

       5.     Supplement to Mortgage, Deed of Trust, Assignment of Production,
Security Agreement and Financing Statement dated as of April 29, 1996, executed
by TTGC, as Mortgagor, for the benefit of the Trustee.

       6.     Security Agreement, Pledge and Financing Statement dated June 20,
1995, by TTGC in favor of the Trustee.

       7.     Pipeline Mortgage, Deed of Trust, Assignment, Security Agreement
and Financing Statement (the "Pipeline Mortgage") dated June 18, 1995, executed
by TransTexas Transmission Corporation ("TTTC") for the benefit of the Trustee.

       8.     Notice of Utility Security Instrument, covering the Pipeline
Mortgage, dated June 18, 1995, executed by TTTC for the benefit of the Trustee.

       9.     Security Agreement, Pledge and Financing Statement dated June 20,
1995, by TTTC in favor of the Trustee.





                                       13
<PAGE>   14
                                  Schedule II

                          New Note Security Documents


       1.     Security and Pledge Agreement dated as of June 13, 1997, made by
TransTexas Energy Corporation ("TransTexas") in favor of Firstar Bank of
Minnesota, N.A., as collateral agent (in such capacity, the "Collateral
Agent");

       2.     Disbursement Agreement dated as of June 13, 1997 by and among
TransTexas Energy Corporation, TransTexas, and Firstar Bank of Minnesota, N.A.,
as disbursement agent (the "TransTexas Disbursement Agreement");

       3.     Act of Mortgage, Security Agreement and Financing Statement dated
as of June 13, 1997, executed by TransTexas in favor of TransTexas Energy
Corporation (the "TransTexas Louisiana Mortgage");

       4.     Mortgage, Deed of Trust, Assignment of Production, Security
Agreement and Financing Statement dated as of June 13, 1997 executed by
TransTexas in favor of James A. Taylor, as trustee for the benefit of
TransTexas Energy Corporation (the "TransTexas Texas Mortgage");

       5.     Mortgage, Deed of Trust, Assignment of Production, Security
Agreement and Financing Statement dated as of June 13, 1997 executed by
TransTexas in favor of James A. Taylor, as trustee for the benefit of
TransTexas Energy Corporation (the "TransTexas Mississippi Mortgage");

       6.     Mortgage, Deed of Trust, Assignment of Production, Security
Agreement and Financing Statement dated as of June 13, 1997 executed by
TransTexas in favor of James A. Taylor, as trustee for the benefit of
TransTexas Energy Corporation (the "TransTexas Alabama Mortgage");

       7.     Mortgage, Deed of Trust, Assignment of Production, Security
Agreement and Financing Statement dated as of June 13, 1997 executed by
TransTexas in favor of TransTexas Energy Corporation (the "TransTexas North
Dakota Mortgage");

       8.     Security and Pledge Agreement dated as of June 13, 1997 (the
"TransTexas Pledge") executed by TransTexas in favor of TransTexas Energy
Corporation;





                                       14