Document:

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                                                                   EXHIBIT 10.75

                           PURCHASE AND SALE AGREEMENT

                                     between

                         TIPPERARY OIL & GAS CORPORATION
                                       AND
                           BURRO PIPELINE CORPORATION

                                   As Sellers

                                       And

                          TRANSREPUBLIC RESOURCES, INC.

                                    As Buyer

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                               TABLE OF CONTENTS

<TABLE>
<S>      <C>                                                                                                    <C>
1.       Assets to be Sold and Purchased; Reservation of Surface Estate                                           1

2        Purchase Price; and Taxes                                                                                2

3.       Warranties, Representations, and Covenants                                                               2

4.       Sellers' Disclaimer of Warranties, Representations, and Covenants                                        4

5.       Certain Covenants of Sellers Pending Closing                                                             5

6.       Due Diligence and Environmental Reviews                                                                  6

7.       Certain Purchase Price Adjustments                                                                      11

8.       Certain Covenants of Buyer Pending Closing                                                              12

9.       Conditions Precedent to the Obligations of Buyer                                                        12

10.      Conditions Precedent to the Obligations of Sellers                                                      13

11.      Termination of Agreement                                                                                13

12.      The Closing                                                                                             14

13.      Certain Post-Closing Adjustments                                                                        16

14.      Commissions                                                                                             17

15.      Casualty Loss                                                                                           17

16.      Notices                                                                                                 17

17.      Survival of Provisions                                                                                  18

18.      Operations                                                                                              18

19.      Confidentiality Agreement                                                                               18

20.      Further Assurances                                                                                      18

21.      Governing Law, and Venue                                                                                19
</TABLE>

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<TABLE>
<S>      <C>                                                                                                    <C>
22.      Costs                                                                                                   19

23.      Entire Agreement; Amendment; and Waiver                                                                 19

24.      Section and Other Headings; and Construction                                                            19

25.      Severability                                                                                            20

26.      Attorney's Fee                                                                                          20

27.      Restrictions on Assignment                                                                              20

28.      Time of the Essence                                                                                     20

29.      Parties in Interest; Successors and Assigns                                                             20

30.      No Publicity                                                                                            20

31.      No Recording                                                                                            21

32.      Indemnifications                                                                                        21
</TABLE>

EXHIBIT A -                     Leases

EXHIBIT B -                     Wells and Allocated Value

EXHIBIT C -                     Quitclaim Assignment and Bill of Sale

EXHIBIT D -                     Reclaimed Pits

EXHIBIT D-1 -                   Officer's Certificate

EXHIBIT D-2 -                   Officer's Certificate

EXHIBIT E -                     Non-Foreign Affidavit

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                           PURCHASE AND SALE AGREEMENT

         This Purchase and Sale Agreement ("AGREEMENT") is entered into this
15th day of June, 2000, by and between Tipperary Oil & Gas Corporation, a Texas
corporation, and Burro Pipeline Corporation, a New Mexico corporation
("SELLERS"), the address each of which is 633 17th Street, Suite 1550, Denver,
Colorado 80202, and Transrepublic Resources, Inc., a Texas corporation
("BUYER"), the address of which is 415 West Wall, Suite 703, Midland, Texas
79701.

                                    RECITALS:

         A. Sellers have certain oil and gas interests that they want to sell to
Buyer in accordance with the terms of this Agreement.

         B. Buyer wants to buy all of Sellers' right, title, and interest in
said oil and gas interests in accordance with the terms of this Agreement.

         NOW THEREFORE, for and in consideration of the terms of this Agreement,
the adequacy of which is hereby acknowledged, the parties agree as follows:

         1. ASSETS TO BE SOLD AND PURCHASED; RESERVATION OF SURFACE ESTATE. (a)
Subject to and in accordance with the terms hereof, Sellers agree to sell and
quitclaim to Buyer, without any warranty, representation, or covenant as to
title, express or implied, statutory or otherwise, and Buyer agrees to purchase
from Sellers, all of Sellers' right, title, and interest, if any, in and to the
following real property, fixtures, and personal property, but only insofar as
they are attributable to the real property described in Exhibit A hereto (the
"PROPERTY"):

                  (i) any and all oil, gas and other mineral interests,
including Sellers' right, title, and interest, if any, in all: (A) oil and gas
leases and any other mineral leases and related easements and rights-of-way, (B)
royalties and overriding royalties, (C) production payments, (D) net profits
interests, (E) reversionary mineral interests, (F) unitization, pooling, and
communitization agreements, and (G) declarations and orders (including all units
formed under orders, rules, regulations, or other official acts of any federal,
state, or other authority having jurisdiction, and voluntary unitization
agreements, designations and declarations);

                  (ii) all fixtures, equipment, gas pipelines, water disposal
gathering lines and related equipment and other personal property, to the extent
relating to the wells described in Exhibit B, situated on the Property; and

                  (iii) all contracts; lease files; abstracts and title
opinions; production records; well files; permits and licenses; copies of
accounting records (but excluding all general financial accounting or tax
accounting records that do not pertain exclusively to the Property); electric
logs and geological, engineering, and other technical data and records (subject
to any contractual or other restrictions relating to the transfer of such data
and records); and other files, documents and records

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that directly relate to the Property; provided however, Sellers may retain
copies of any or all of the foregoing.

         Sellers' interests, if any, in the real property, fixtures, and
personal property described in subsections (i) and (ii) are sometimes
collectively referred to as "OIL AND GAS PROPERTIES," or as an "OIL AND GAS
PROPERTY". Sellers' interests, if any, in the Oil and Gas Properties and in the
personal property described in subsection (iii) are sometimes collectively
called the "ASSETS."

         (b) Sellers except and reserve a concurrent right to utilize any
easements or right-of-way rights in and to the surface estate of the property
and all rights of any nature whatsoever appurtenant or otherwise associated
therewith, whether said rights-of-way are under said leases or otherwise, and
such right, title, and interest does not constitute any part of the Assets. The
reservation of these concurrent rights shall be in addition to and not limit the
statutory, contractual, or common law rights of Buyer to use the surface estate
for the development of the Oil and Gas Property described herein.

         2. PURCHASE PRICE; AND TAXES. (a) The purchase price for the Assets
("PURCHASE PRICE") shall be Four Million Dollars ($4,000,000) as adjusted as
provided herein. The Purchase Price shall be paid at the Closing (hereinafter
defined) as hereinafter provided. Said $4,000,000, without regard to any
adjustments, however, is sometimes referred to herein as the "BASE PURCHASE
PRICE."

         (b) Buyer has paid Sellers Four Hundred Thousand Dollars ($400,000)
("DEPOSIT") by check drawn on a national bank in immediately available funds. If
for any reason said check should be dishonored, then at Sellers' option, and in
addition to any other rights they may have, they may terminate this Agreement.
If Buyer and Sellers consummate the purchase and sale of the Assets, the Deposit
shall be credited against the Purchase Price. The Deposit shall be returned to
Buyer:

                  (i) only if: (A) Sellers refuse to consummate the purchase and
sale of the Assets and (B) such refusal would constitute a breach hereof, or

                  (ii) only under the other circumstances, if any, expressly set
forth herein.

If Buyer fails to consummate the transactions contemplated by this Agreement, or
if the transactions contemplated by this Agreement otherwise fail to close on
the Closing Date (hereinafter defined), Sellers shall retain the Deposit as
liquidated damages. The parties agree that damages in such an event are
uncertain in amount and cannot be determined with reasonable certainty in
advance, that the amount of the Deposit constitutes a fair and reasonable
estimate of (and is not disproportionate to) actual Damages such a breach would
cause, and is not a penalty or an inducement to perform.

         (c) Buyer shall pay any and all sales, use, documentary, and transfer
taxes and fees imposed on this transaction, and shall pay all recording and
filing fees.

         3. WARRANTIES, REPRESENTATIONS, AND COVENANTS. (a) Each party, as to
itself only, warrants, represents, and covenants to the other party that:

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                  (i) It is a corporation duly organized, legally existing and
in good standing under the laws of the state of its incorporation, as first set
out above.

                  (ii) It is qualified to do business and is, or at Closing will
be, in good standing in each state in which the Oil and Gas Properties are
located where the laws of such state require a corporation owning the Oil and
Gas Properties located in such state to qualify to do business.

                  (iii) It has full power to enter into and perform its
obligations under this Agreement; the execution, delivery, and performance of
this Agreement and the consummation of the transactions contemplated hereby have
been duly authorized by all requisite corporate action; and this Agreement has
been duly executed and delivered.

                  (iv) This Agreement, and the Assignment (hereinafter defined)
to be delivered at Closing, will, when executed, delivered, and accepted,
constitute each such party's legal, valid and binding obligation, enforceable in
accordance with its terms, except as limited by bankruptcy or other laws
applicable generally to creditor's rights and as limited by general equitable
principles.

                  (v)(A) There are no pending material suits, actions, or other
proceedings to which it is a party that affect: (I) the Assets (including, as to
Sellers, any actions challenging or pertaining to their title to any Assets), or
(II) the execution and delivery of this Agreement or the consummation of the
transactions contemplated hereby, and (B) it shall promptly notify the other
party of any such material suits, actions, or other proceedings as to which
after the date hereof it receives a written threat of assertion.

                  (vi) It shall protect, defend, indemnify, and hold harmless
the other party and its affiliates, and their employees, agents, successors and
assigns, from and with respect to any and all rights, claims, demands, causes of
action, and legal, administrative, or arbitration proceedings, of any and every
nature (collectively, "CLAIMS"), and injuries, deaths, damages, and obligations
of any and every nature resulting from or that gave rise to any Claim, including
liabilities, losses, costs, penalties, expenses, judgments, fines, settlements,
interest, reasonable attorney's fees, and other related expenses of any nature
(collectively, "DAMAGES") resulting from a breach of its warranties,
representations, or covenants; provided however, that Damages shall not include
consequential, special, incidental, or punitive damages.

         (b) Sellers warrant and represent to Buyer that other than:

                  (i) requirements (if any) that consents to assignment of
Assets, or waivers of preferential rights to purchase Oil and Gas Properties, be
obtained from third parties, or

                  (ii) requirements to obtain consents or approvals from, or to
submit notices to or applications to, or actions that must be taken by,
governmental entities (in their capacity as lessors of oil and gas leases,
grantors of rights-of-way, or otherwise, whether similar to or different from
the foregoing) in connection with the sale or conveyance of oil and gas leases,
permits, or interests therein, or of rights or interests of the nature of any of
the Assets, if the same are customarily obtained contemporaneously with or
subsequent to such sale or conveyance;

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neither their execution and delivery of this Agreement, nor its consummation of
the transactions contemplated hereby, nor their compliance with the terms
hereof, will violate or result in any default under its articles of
incorporation or by-laws, or under any agreements to which it is a party or by
which it is bound, or violate any federal, state, or local law (including
statutory and case law), rule, regulation, ordinance, permit, license, order,
judgment, injunction, writ, or decree of any nature (collectively "LAW")
applicable to it or to the Assets.

         (c) Buyer warrants and represents to Sellers that:

                  (i) It is a knowledgeable and experienced purchaser, owner and
operator of oil and gas properties, has the ability to evaluate oil and gas
properties, and, subject to its rights under Section 6, has been given the
opportunity to investigate and evaluate (and has investigated and evaluated) the
condition of the Assets to the extent it deems necessary or appropriate and is
acquiring the Assets based solely upon its own investigation and evaluation and
for its own account, and not with a view to or the intent to make a resale or
distribution within the meaning of the Securities Act of 1933 (and the rules and
regulations pertaining thereto) or a resale or distribution thereof in violation
of any other applicable securities laws.

                  (ii) With respect to any Assets that comprise leases issued by
any governmental entity, it is qualified to become the successor lessee of such
leases and assumes the risk of being approved as the successor lessee of such
leases.

                  (iii) Neither its execution and delivery of this Agreement,
nor its consummation of the transactions contemplated hereby, nor its compliance
with the terms hereof, will violate or result in any default under its articles
of incorporation or by-laws, or under any agreement to which it is a party or by
which it is bound, or violate any Law applicable to it or to the Assets.

         4. SELLERS' DISCLAIMER OF WARRANTIES, REPRESENTATIONS, AND COVENANTS.
(A) WITH RESPECT TO THE ASSETS, THIS AGREEMENT, AND THE TRANSACTIONS
CONTEMPLATED HEREBY, SELLERS' WARRANTIES AND REPRESENTATIONS AS EXPRESSLY SET
OUT IN SECTION 3 HEREOF AND IN THE ASSIGNMENT EXECUTED PURSUANT HERETO ARE
EXCLUSIVE AND IN LIEU OF ANY AND ALL OTHER WARRANTIES, REPRESENTATIONS, AND
COVENANTS, EXPRESS OR IMPLIED, STATUTORY OR OTHERWISE, AND SELLERS DISCLAIM ANY
AND ALL OTHER WARRANTIES, REPRESENTATIONS, AND COVENANTS, EXPRESS OR IMPLIED,
STATUTORY OR OTHERWISE.

         (B) CONSISTENT WITH AND NOT AS A LIMITATION ON SUBSECTION (A), THE
ASSETS SHALL BE PURCHASED, SOLD, AND CONVEYED "AS IS, WHERE IS", WITHOUT ANY
WARRANTY, REPRESENTATION, OR COVENANT, EXPRESS OR IMPLIED, STATUTORY OR
OTHERWISE, RELATING TO:

                  (I) THE CONDITION, QUANTITY, QUALITY, FITNESS FOR A PARTICULAR
PURPOSE OR ANY PURPOSE, CONFORMITY TO THE MODELS OR SAMPLES OF MATERIALS, OR
MERCHANTABILITY OF ANY IMMOVABLE PROPERTY, MOVABLE PROPERTY, EQUIPMENT,
INVENTORY, MACHINERY, AND OTHER FIXTURES AND PERSONAL PROPERTY CONSTITUTING PART
OF THE ASSETS;

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                  (II) ANY IMPLIED OR EXPRESS WARRANTY OF FREEDOM FROM
REDHIBITORY VICES OR DEFECTS OR OTHER VICES OR DEFECTS, WHETHER KNOWN OR
UNKNOWN;

                  (III) ANY AND ALL IMPLIED WARRANTIES, REPRESENTATIONS, OR
COVENANTS EXISTING UNDER APPLICABLE LAW NOW OR HEREAFTER IN EFFECT; AND

                  (IV) EXCEPT AS PROVIDED OTHERWISE IN SUBSECTION (A), WITHOUT
ANY OTHER WARRANTY, REPRESENTATION, OR COVENANT, EXPRESS OR IMPLIED, STATUTORY
OR OTHERWISE.

         (C) CONSISTENT WITH BUT NOT AS A LIMITATION ON SUBSECTIONS (A) AND (B),
SELLERS ARE SELLING AND BUYER IS BUYING THE ASSETS WITH ALL DEFECTS AND FAULTS
(LATENT OR APPARENT) AND IT ASSUMES THE RISK THAT ADVERSE PAST, PRESENT OR
FUTURE PHYSICAL CONDITIONS MAY NOT HAVE BEEN REVEALED BY ITS INVESTIGATIONS.

         5. CERTAIN COVENANTS OF SELLERS PENDING CLOSING. Between the date
hereof and the Closing Date:

         (a) Sellers will give Buyer, its attorneys and other representatives,
subject to the provisions of the Confidentiality Agreement dated January 20,
2000, heretofore executed by Buyer ("CONFIDENTIALITY AGREEMENT") and subject to
any restrictions on access to the Assets imposed by agreements by which Sellers
are bound, access at all reasonable times to: (i) the Assets and (ii) Sellers'
records and files, to the extent located at Sellers' offices, relating to the
Assets (which records and files include those relating to title, division
orders, wells, production, accounting, marketing, equipment inventories, and
production, severance and ad valorem taxes). Notwithstanding the foregoing,
Sellers shall not be obligated to provide Buyer with access to any files or
records that it cannot legally provide to Buyer without, in Sellers' opinion,
breaching or risking a breach of confidentiality agreements. All such files and
records are being made available to Buyer (whether pursuant to this Section or
otherwise) as an accommodation, and without representation, warranty, or
covenant, express or implied, statutory or otherwise, as to the accuracy and
completeness of such materials.

         (b) To the extent Sellers are the operator of any Oil and Gas
Properties, they will continue such operation in the ordinary course of their
business; and where they are not the operator of any Oil and Gas Properties,
they will continue their actions as a non-operator in the ordinary course of
their business. Sellers will not sell or dispose of any portion of the Assets
without Buyer's prior consent, which shall not be unreasonably withheld.

         (c)(i)(A) Sellers shall review their own records (including all
operating agreements, to which they are a party, applicable to the Oil and Gas
Properties) to identify: (I) all preferential rights to

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purchase any Assets, (II) all rights to require that consents to assignment of
any Assets be obtained, and (III) the parties holding any of such rights. In
identifying the foregoing, Sellers shall have no obligation to review anything
other than their own records.

                           (B) Sellers will request, from the parties so
identified under subsection (A) and from any other third parties identified by
Buyer in a Defect Notice (hereinafter defined) given to Sellers by the Defect
Date (hereinafter defined) (and in accordance with the documents creating such
rights), waivers of the preferential rights to purchase and requirements that
consents to assignment be obtained which were so identified. Sellers shall have
no obligation hereunder other than to so attempt to identify such preferential
rights and requirements for consents to assignment and to so request such
waivers, and shall have no obligation to obtain such waivers. Unless Buyer can
establish that Sellers failed to fulfill their obligations under this
subsection, Buyer shall protect, defend, indemnify and hold Sellers harmless
from and against all Claims and Damages arising out of any failure to obtain
waivers of preferential rights to purchase or requirements for consents to
assignment with respect to any transfer by Sellers to Buyer of any Assets and
with respect to any subsequent transfers.

                  (ii) If the holder of a preferential right to purchase an
Asset fails or refuses to give such waiver and instead exercises such right,
Sellers will tender to such holder (at a price equal to the amount specified in
Exhibit B hereto for the wells located on such Asset and for the units in which
such Asset participates, reduced appropriately, as determined by Sellers, if
less than the entire Asset should be tendered, unless it is determined that a
greater or lesser price is required) the interest in the Asset affected by such
preferential right. If such interest in such Asset is actually sold to such
holder, it will be excluded from the transaction contemplated hereby and the
Purchase Price will be reduced by the amount paid to Sellers by the holder
exercising such right; provided however, that if the holder of such right
believes the Allocated Value (hereinafter defined) is too high, Sellers shall
promptly notify Buyer, and Sellers and Buyer shall cooperate to address such
assertion by the holder of such right.

         (d) Notwithstanding anything in this Section to the contrary: (i)
Sellers may take any action prohibited by this Section if reasonably necessary
under emergency conditions, provided that Buyer is notified as soon as
practicable thereafter; (ii) except to the extent a "DEFECT" ( hereinafter
defined) may result therefrom, Sellers shall have no liability to Buyer for any
incorrect payment of delay rentals, royalties, shut-in royalties or similar
payments or for any failure to make such payments; and (iii) Sellers' failure to
comply with any of the requirements of this Section shall not be deemed a
default by Sellers hereunder or entitle Buyer to not close the transactions
contemplated hereby, unless such failure has a materially adverse impact on the
value of the Assets taken as a whole.

         6. DUE DILIGENCE AND ENVIRONMENTAL REVIEWS. (a)(i) To the extent deemed
appropriate by Buyer, it may conduct, at its sole cost and risk, such title
examinations and, subject to any restrictions to which Sellers are bound, any
other reasonable examinations and investigations as it may choose with respect
to the Assets; provided however, environmental examinations and investigations
shall be governed by subsection (b). If as a result of such examinations and
investigations Buyer identifies any matters that constitute Defects, and if
there are any Defects that Buyer is unwilling to waive, Buyer must notify
Sellers of such Defects ("DEFECT NOTICE") promptly following its discovery of
such Defects, but in no event later than June 23, 2000 ("DEFECT DATE").

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Buyer may not give notice of any Defects after the Defect Date, and must accept
all Defects, if any, discovered after the Defect Date.

                  (ii) To be effective, a Defect Notice must include: (A) a
brief description of the matter constituting the alleged Defect, (B) the title
opinion, expert's report, or other documentation on which the alleged Defect is
based, (C) such supporting documents reasonably necessary for Sellers to
determine if a Defect actually exists, and (D) Buyer's estimate of the
diminution in the sum to be paid at Closing resulting from such alleged Defect.
Alleged Defects for which Buyer provides a valid Defect Notice no later than the
Defect Date are herein called "ASSERTED DEFECTS."

                  (iii) Except for Asserted Defects, all matters that might
otherwise constitute a Defect are waived for all purposes hereof. With respect
to any Asserted Defect, Sellers shall have the right but not the obligation to:
(A) attempt to cure it prior to Closing, (B) require that the Closing take
place, deposit in an escrow account the portion of the Purchase Price paid by
Buyer and attributable to the Asset having the Asserted Defect, and attempt to
cure such Asserted Defect within thirty (30) days after the Closing, and
Sellers' right under this clause (B) may be exercised at any time before the
Closing; or (C) elect not to cure the Asserted Defect and adjust the Purchase
Price as provided in Section 7. If Sellers, on or before the Closing, exercise
any such right as to an Asserted Defect, then such Asserted Defect shall be
deemed to have been cured.

                  (iv) With respect to any Oil and Gas Property, if a title
opinion or any other materials reviewed by Buyer indicates Sellers have a "NET
REVENUE INTEREST" (hereinafter defined) greater than that specified on Exhibit
B, then Buyer shall promptly inform Sellers of the same, but in any event at
least five (5) days prior to the Closing. If Sellers or Buyer determine that
Sellers are entitled to a Net Revenue Interest in any Asset in excess of that
set forth on Exhibit B ("NRI INCREASE"), notice shall promptly be given to the
other party, and the adjustments to be made under Section 7 shall include
adjustments which are the subject of such notice.

         (b)(i)(A) To the extent, if any, that Sellers have the right to grant
Buyer the right to do so, Buyer may, upon at least four (4) day's notice to
Sellers, enter upon the Oil and Gas Properties to conduct an environmental
assessment of the Assets at Buyer's sole cost and risk. (B) Consistent with but
not as a limitation on the foregoing, Buyer shall protect, defend, indemnify,
and hold Sellers and anyone else owning an interest in the Oil and Gas
Properties harmless from and against any Claims and Damages resulting from the
presence or activities of Buyer or its agents on the Oil and Gas Properties in
the course of conducting its assessment activities.

                  (ii)(A) In conducting its assessment, and subject to
subsection (i), Buyer may enter upon the Oil and Gas Properties, without
disrupting operations thereon, and inspect the same, conduct soil and water
tests and borings, and generally conduct such tests, examinations,
investigations, and studies as may be necessary or appropriate for the
preparation of appropriate engineering and other reports in relation to the Oil
and Gas Properties, their condition, and the presence of Hazardous Substances
(hereinafter defined). Any such assessment shall be concluded no later than June
26, 2000 ("ENVIRONMENTAL ASSESSMENT DATE"). If there are any Oil and Gas
Properties as to which Sellers do not have the right to grant Buyer the right to
conduct an assessment, or if as a result of Buyer's environmental assessment any
particular Oil and Gas Property is determined to be in material violation of
environmental Laws, then Buyer, no later than the

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Environmental Assessment Date, may notify Sellers that Buyer wants to exclude
such Oil and Gas Property from this Agreement (and such notice, if and to the
extent regarding a violation of environmental Laws, shall provide in reasonable
detail the Law that was violated, the manner in which such Law was violated, and
sufficient information to substantiate the violation), in which event said Oil
and Gas Property shall be excluded and the Purchase Price shall be reduced, with
such reduction in the Purchase Price being determined as provided in Section 7.
After the Environmental Assessment Date: (I) Buyer may not request that any Oil
and Gas Property be excluded from this Agreement due to Sellers not having the
right to grant Buyer the right to conduct an environmental assessment as to such
Oil and Gas Property or due to any violation of environmental Laws as to such
Oil and Gas Property, and (II) Buyer shall be deemed to have inspected the Oil
and Gas Properties or waived its right to inspect the Oil and Gas Properties for
all purposes and satisfied itself as to their physical and environmental
condition, both surface and subsurface, including conditions specifically
related to the presence or release of any substance or material defined or
designated as hazardous or toxic waste, hazardous or toxic material, hazardous
or toxic substance, or other similar term, by any Law relating to the
environment (collectively, "HAZARDOUS SUBSTANCES").

                           (B) Sellers have been performing environmental
remediation operations with respect to substances that had been deposited or
otherwise disposed in nine (9) pits in the portion of the Oil and Gas Properties
known as Bagley Field. The nature of such operations has been, and is, using
windmill powered pumps to remove Benzene from the water. The nine (9) pits for
which such operations are currently being conducted are listed on Exhibit D.
Such environmental remediation operations will not be completed as of the
Closing Date, and as of the Effective Date, Sellers shall be responsible for all
environmental remediation work and any costs associated therewith regarding said
nine (9) pits. Sellers shall protect, defend, indemnify, and hold Buyer harmless
from any claims, fines, or damages associated with the performance of
environmental remediation operations on pits described in Exhibit D herein.
Notwithstanding anything herein to the contrary, the Purchase Price shall not be
reduced, and no Oil and Gas Property may be excluded, due to any matters
relating to the need to continue environmental remediation operations with
respect to said nine (9) pits. Sellers reserve the right to continue, at no cost
to Sellers, disposing of produced water from field remediation operations, into
the O. G. State No. 2 disposal well. Buyer shall have the right to test Sellers'
water from these operations.

                  (iii)(A) Buyer shall provide Sellers with a copy of any
environmental assessment and other reports, and all supporting data and other
documentation, promptly upon completion of the assessment. Buyer shall keep any
data or information acquired by such examinations and the results of all
analyses of such data and information strictly confidential and shall not
disclose them to anyone without Sellers' prior written approval, which need not
be given by Sellers.

                           (B) The consent required by subsection (A) shall not
apply to a disclosure to a governmental agency that Buyer believes upon written
advice of counsel is required by Law; provided however, that in such event,
Buyer shall give notice to Sellers (which notice shall describe in a reasonably
detailed manner the legal grounds on which such advice is based) at least ten
(10) days prior to making such disclosure, and shall take into account any
comments Buyer may receive from Sellers. Sellers shall have the right to contest
the need to disclose any information, and Buyer shall protect, defend,
indemnify, and hold

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Sellers harmless from any Claims or Damages resulting from any disclosure that
was not required by Law. Sellers shall protect, defend, indemnify, and hold
Buyer harmless from Sellers' acts with respect to (1) withholding consent in
accordance with subsection (A) herein, or (2) exercising Sellers' right to
contest the need to disclose any information contemplated herein.

         (c) As used herein, "DEFECT" means any matter, other than a "PERMITTED
ENCUMBRANCE" (hereinafter defined), which causes one or more of the following to
be a correct statement:

                  (i) Sellers' ownership of an Asset is such that, with respect
to a well or unit listed on Exhibit B, such ownership: (A) is insufficient to
entitle it to receive a decimal share of the oil, gas and other hydrocarbons
produced from, or allocated to, such well or unit that is at least equal to the
decimal share set forth on Exhibit B in the column "Net Revenue Interest" or (B)
obligates it to bear a decimal share of the cost of operating such well or unit
("OPERATING INTEREST") greater than the decimal share set forth on Exhibit B in
the column "Operating Interest" without a proportionate increase in the
corresponding Net Revenue Interest set forth on such Exhibit;

                  (ii) Sellers' ownership of an Oil and Gas Property is subject
to an outstanding and valid mortgage, deed of trust, other lien or encumbrance,
or other adverse claim or imperfection in title, which if asserted would cause
either subsection (i)(A) or (i)(B) to be a correct statement; or

                  (iii) Sellers have inaccurately and materially represented or
failed to represent the amount of any gas imbalances.

                  (iv) Any product sales contracts that have not been disclosed
to Buyer before closing.

         (d) As used herein, "PERMITTED ENCUMBRANCE" shall mean any and all of
the following:

                  (i) The conditions, restriction, exceptions, reservations,
limitations and all other terms contained in the agreements and instruments in
the chain of title that creates or reserves to Sellers their interest in any
Asset, provided that the same do not reduce Sellers' Net Revenue Interest in the
affected Asset to less than that set forth on Exhibit B;

                  (ii) Royalties, overriding royalties (including those
specifically described on Exhibit A), division orders, reversionary interests,
production payments, net profits interests and similar burdens affecting any Oil
and Gas Property if the net cumulative effect of such burdens does not reduce
Sellers' Net Revenue Interest in the affected Asset to less than that set forth
on Exhibit B;

                  (iii) Preferential rights to purchase, requirements that third
party consents be obtained for assignments, and agreements of a similar nature,
with respect to which waivers or consents shall have been obtained from the
appropriate parties, or the appropriate time period for asserting such rights
shall have expired without an exercise of such rights;

                  (iv) Taxes and assessments which are not yet delinquent or
which are being contested by Sellers in good faith;

                  (v) Conditional rights of reassignment requiring ninety (90)
days or less notice to the holder of such rights; the conditions which have not
occurred or will not occur prior to Closing.

                                       9
<PAGE>   13

                  (vi) Easements, rights-of-way, servitudes, permits, surface
leases and other rights in respect to surface operations, pipelines, logging,
canals, ditches, reservoirs or the like; conditions, covenants or other
restrictions; easements for streets, alleys, highways, pipelines, telephone
lines, power lines, railways and other easements or rights-of-way on, over or
with respect of any Asset which do not materially and adversely affect the Asset
affected thereby or its current use;

                  (vii) Any obligations or duties affecting an Asset to any
municipality or public authority with respect to any franchise, grant, license
or permit and all applicable Laws of any governmental authority;

                  (viii) Existing operating agreements, unit agreements, gas
purchase contracts and any and all other agreements that are typical in the oil
and gas exploration, development, production or extraction business or in the
business of processing of gas and gas condensate or production for the
extraction of proper products therefrom, to the extent that the same do not
reduce Sellers' Net Revenue Interest in the affected Asset to less than that set
forth on Exhibit B;

                  (ix) Any other defect or imperfection in title which would
customarily be waived by a reasonable person engaged in the business of owning
and operating oil and gas properties; and

                  (x) Any other matter waived or deemed to be waived by Buyer
pursuant to the provisions of subsection (a).

         (e) With respect to all Assets conveyed to Buyer hereunder:

                  (I) BUYER SHALL BE DEEMED TO HAVE: (A) INSPECTED, OR TO HAVE
WAIVED ITS RIGHT TO INSPECT, THE ASSETS FOR ALL PURPOSES, AND (B) SATISFIED
ITSELF AS TO THEIR PHYSICAL AND ENVIRONMENTAL CONDITION, BOTH SURFACE AND
SUBSURFACE, INCLUDING CONDITIONS SPECIFICALLY RELATED TO THE PRESENCE, RELEASE,
OR DISPOSAL OF SOLID WASTES, ASBESTOS, OTHER MANMADE FIBERS, NATURALLY OCCURRING
RADIOACTIVE MATERIALS, AND OTHER HAZARDOUS SUBSTANCES IN, ON, OR UNDER THE OIL
AND GAS PROPERTIES.

                  (II) BUYER SHALL BE DEEMED TO HAVE RELIED SOLELY ON ITS OWN
INSPECTION OF THE ASSETS, AND AS PROVIDED IN SECTION 4, SELLERS ARE SELLING AND
BUYER IS BUYING ALL ASSETS "AS IS, WHERE IS." CONSISTENT WITH BUT NOT AS A
LIMITATION ON THE FOREGOING, SELLERS MAKE NO WARRANTY, REPRESENTATION, OR
COVENANT, EXPRESS OR IMPLIED, STATUTORY OR OTHERWISE, AS TO THE ACCURACY OR
COMPLETENESS OF ANY DATA, REPORTS, RECORDS, PROJECTIONS, INFORMATION, OR OTHER
MATERIALS NOW, HERETOFORE, OR HEREAFTER FURNISHED OR MADE AVAILABLE TO BUYER IN
CONNECTION WITH THIS AGREEMENT, INCLUDING PRICING ASSUMPTIONS OR QUALITY OR
QUANTITY OF HYDROCARBON RESERVES (IF ANY) ATTRIBUTABLE TO THE ASSETS OR THE
ABILITY OR POTENTIAL OF THE ASSETS TO PRODUCE HYDROCARBONS OR THE ENVIRONMENTAL
CONDITION OF THE ASSETS OR ANY OTHER MATERIALS

                                       10
<PAGE>   14

FURNISHED OR MADE AVAILABLE TO BUYER BY OR ON BEHALF OF SELLERS. ANY AND ALL
SUCH DATA, REPORTS, RECORDS, PROJECTIONS, INFORMATION, AND OTHER MATERIALS
FURNISHED BY OR ON BEHALF OF SELLERS TO BUYER ARE PROVIDED TO BUYER AS A
CONVENIENCE AND SHALL NOT CREATE OR GIVE RISE TO ANY LIABILITY OF OR AGAINST
SELLERS, AND ANY RELIANCE ON OR USE OF THE SAME SHALL BE AT BUYER'S SOLE RISK.

         7. CERTAIN PURCHASE PRICE ADJUSTMENTS. (a) If in connection with the
due diligence review under Section 6 either: Asserted Defects are presented to
Sellers and Sellers are unable or unwilling to cure such Asserted Defects prior
to Closing, Buyers have elected to treat an Oil and Gas Property affected by a
casualty loss as if it was an Oil and Gas Property affected by an Asserted
Defect, or an NRI Increase occurs, or an Oil and Gas Property is excluded under
Section 6(b)(ii), or 6(c) then:

                  (i)(A) If the Asserted Defect is a mortgage, deed of trust,
lien, encumbrance or other charge which is undisputed and liquidated in amount,
then the adjustment shall be the amount necessary to be paid to remove the
Asserted Defect from the affected Oil and Gas Property;

                           (B) If there is: (I) an Asserted  Defect or NRI
Increase that represents a discrepancy between the Net Revenue Interest that
Sellers are entitled to receive from any Oil and Gas Property and the Net
Revenue Interest stated on Exhibit B, and (II) an Operating Interest change
proportionate to the change in the Net Revenue Interest resulting from the
Asserted Defect or NRI Increase, then the amount of the adjustment shall be the
product of the value allocated by Buyer (and Buyer represents said value was
allocated in good faith) to such Oil and Gas Property as set forth on Exhibit B
("ALLOCATED VALUE") multiplied by a fraction, the numerator of which shall be
the change in the Net Revenue Interest and the denominator of which shall be the
Net Revenue Interest set forth on Exhibit B; and

                           (C) If an Oil and Gas Property is excluded under
Section 6(b)(ii) or 6(c), then the Purchase Price shall be reduced by the
Allocated Value of the Wells located on such Oil and Gas Property.

                  (ii) If the Asserted Defect represents an obligation,
encumbrance, burden, discrepancy or charge upon or other defect in title to the
affected Oil and Gas Property of a type not described in subsections (i)(A) or
(i)(B), the adjustment amount shall be determined by taking into account the
Allocated Value of the Oil and Gas Property so affected, the portion of the Oil
and Gas Property affected by the Asserted Defect, the legal effect of the
Asserted Defect, the potential economic effect of the Asserted Defect over the
life of the affected Oil and Gas Property and such other factors as are
necessary to make a proper evaluation of the value of the Asserted Defect;
provided further, that if the parties cannot agree upon an appropriate
adjustment in light of the foregoing factors, then subject to subsection (b),
either Buyer or Sellers may elect to exclude such Oil and Gas Property from the
transaction contemplated hereby, and the Purchase Price will be reduced by the
Allocated Value of the wells located on such Oil and Gas Property and the units
in which the related Oil and Gas Property participates.

                                       11
<PAGE>   15

                  (iii) Notwithstanding anything herein to the contrary: (A) the
aggregate reduction attributable to the effect of all Asserted Defects related
to a given Oil and Gas Property shall not exceed the Allocated Value of the
Wells located on such Oil and Gas Property; and (B) no reduction shall be made
with respect to an Asserted Defect if the diminution in the Allocated Value
regarding such Oil and Gas Property resulting therefrom regarding said asset
will not exceed Twelve Thousand Five Hundred Dollars ($12,500.00).

         (b)(i) If the aggregate Purchase Price reductions which would result
under subsections (a) and (c) do not exceed two percent (2%) of the Base
Purchase Price, then the Purchase Price shall not be adjusted, and none of the
Oil and Gas Properties which would be excluded by such procedure shall be
excluded.

                  (ii) If the aggregate Purchase Price reductions which would
result under subsections (a) and (c) exceed two percent (2%) of the Base
Purchase Price, the Purchase Price shall be adjusted by the amount by which such
decreases exceed two percent (2%) of the Base Purchase Price. If the Purchase
Price increase which would result under subsection (a) exceeds two percent (2%)
of the Base Purchase Price, the Purchase Price shall be adjusted by the amount
by which such increase exceeds two percent (2%) of the Base Purchase Price.

         (c) If Buyer, prior to the Defect Date, provides Sellers with evidence
reasonably satisfactory to Sellers that the disposal well operated by Sellers in
the Bagley Field does not pass the mechanical integrity test required by Law,
then: (i) prior to Closing, Sellers shall repair said disposal well so as to
bring it into compliance with Law, or (ii) the Base Purchase Price shall be
reduced by an amount equal to that necessary to bring said disposal well into
compliance with Law.

         (d) If the net aggregate amount of all Purchase Price reductions under
this Agreement, regardless of the reason for such reductions, exceeds five
percent (5%) of the Base Purchase Price, either party may terminate this
Agreement by giving notice to the other party within ten (10) days of the date
it was determined that the Purchase Price reduction would exceed said five
percent (5%), in which event this Agreement shall terminate and the Deposit
shall be returned to Buyer. Upon such termination, the parties shall have no
further obligations to one another hereunder (other than the indemnification
obligations under Sections 3(a)(vi) and 6(b), and the obligations under and
Sections 11(c), 14 and 19 - 26, which will survive such termination).

         (e) Notwithstanding anything herein to the contrary, the Purchase Price
shall not be reduced, and no Oil and Gas Property may be excluded, due to any
matters relating to the plugging and abandonment of wells listed on Exhibit "B."

         8. CERTAIN COVENANTS OF BUYER PENDING CLOSING. If the purchase and sale
of the Assets is consummated, then for a period of seven (7) years from the
closing, Buyer shall save and retain, and give Sellers access at all reasonable
times upon reasonable notice, to all files and records (including all computer
records) delivered by or on behalf of Sellers in connection with the transaction
contemplated hereby, and shall permit Sellers to make copies of any such files
and records. Consistent with but not as a limitation on Section 29, if the
Assets are subsequently transferred by Buyer, Buyer shall take all action in its
contractual arrangements relating to such transfer necessary to allow Sellers to
have continued access to all such files and records.

                                       12
<PAGE>   16

         9. CONDITIONS PRECEDENT TO THE OBLIGATIONS OF BUYER. Buyer's obligation
to purchase the Assets is subject to each of the following conditions being met:

         (a) Each and every warranty and representation of Sellers under this
Agreement shall be true and accurate in all material respects as of Closing, the
same as if made at Closing, except as to changes specifically contemplated by
this Agreement or waived by Buyer.

         (b) Sellers shall have complied in all material respects (or compliance
shall have been waived by Buyer) with each and every covenant required by this
Agreement to be performed by Sellers prior to or at the Closing.

         (c) No suit, action or other proceedings shall, on the date of Closing,
be pending, or threatened in writing, before any court or governmental agency
seeking to restrain, prohibit, or obtain damages or other relief in connection
with the consummation of the transactions contemplated by this Agreement.

         (d) Any and all other conditions precedent in Buyer's favor have been
satisfied or waived.

         10. CONDITIONS PRECEDENT TO THE OBLIGATIONS OF SELLERS. Sellers'
obligation to sell the Assets is subject to each of the following conditions
being met:

         (a) Each and every warranty and representation of Buyer under this
Agreement shall be true and accurate in all material respects as of Closing, the
same as if made at Closing, except as to changes specifically contemplated by
this Agreement or waived by Sellers.

         (b) Buyer shall have complied in all material respects (or compliance
shall have been waived by Sellers) with each and every covenant required by this
Agreement to be performed by Buyer prior to or at the Closing.

         (c) No suit, action or other proceedings shall, on the date of Closing,
be pending, or threatened in writing, before any court or governmental agency
seeking to restrain, prohibit, or obtain damages or other relief in connection
with the consummation of the transactions contemplated by this Agreement.

         (d) Any and all other conditions precedent in Sellers' favor have been
satisfied or waived.

         11. TERMINATION OF AGREEMENT. (a) If: (i) any condition precedent set
forth in Section 9 to Buyer's obligation to purchase the Assets is not satisfied
or waived as of the Closing Date, or if the Closing does not occur on or before
July 7, 2000 ("TERMINATION DATE"), then Buyer may terminate this Agreement upon
seven (7) days notice to Sellers unless, as to a notice of termination given due
to a condition precedent not being satisfied or waived, the condition precedent
is satisfied within said seven days regardless of whether or not extending
beyond the Termination Date, in which case the Closing shall occur within three
(3) business days after the condition precedent was satisfied. If such
termination occurs and Buyer is not in breach of its warranties,
representations, or obligations hereunder at the time such notice of termination
was given, then Sellers shall return the Deposit to Buyer within said seven
days. Upon such termination, the parties shall have no further

                                       13
<PAGE>   17

obligations to one another hereunder (other than the indemnification obligations
under Sections 3(a)(vi) and 6(b), and the obligations under subsection (c) and
Sections 14 and 19 - 26, which will survive such termination).

         (b) If any condition precedent set forth in Section 10 to Sellers'
obligation to sell the Assets is not satisfied or waived as of the Closing Date,
or if the Closing does not occur on or before the Termination Date, then Sellers
may terminate this Agreement upon seven (7) days notice to Buyer unless, as to a
notice of termination given due to a condition precedent not being satisfied or
waived, the condition precedent is satisfied within said seven days regardless
of whether or not extending beyond the Termination Date, in which case the
Closing shall occur within three (3) business days thereafter. If such
termination occurs, Sellers shall return the Deposit to Buyer only if the
termination was based solely on Section 2(b). Upon such termination, the parties
shall have no further obligations to one another hereunder (other than the
indemnification obligations under Sections 3(a)(vi) and 6(b), and the
obligations under subsection (c) and Sections 14 and 19 - 26, which will survive
such termination).

         (c) Upon termination of this Agreement under either subsection (a) or
(b), or under Section 7(d), Sellers may sell the Assets (or any portion thereof)
to any third party without any limitation under or by reason of this Agreement,
and Buyer shall not seek to enjoin any such sale and shall not otherwise
institute any Claim regarding any such sale. In the event of termination,
promptly following Sellers' request, Buyer shall: (i) execute any instrument
requested by Sellers to evidence the termination of Buyer's right to acquire the
Assets, and (ii) return to Sellers all data and other information (and all
copies thereof) furnished to Buyer by or on behalf of Sellers in connection with
this transaction.

         12. CLOSING. (a)(i) The closing ("CLOSING") of the transaction
contemplated hereby shall take place in the offices of Sellers, in Denver,
Colorado, on June 30, 2000, at 10:00 a.m. Mountain Time, or at such other date
and time as Buyer and Sellers may agree ("CLOSING DATE").

                  (ii) At least three (3) business days before the Closing Date,
Sellers shall submit to Buyer a proposed statement ("CLOSING STATEMENT") setting
forth the proposed Purchase Price, based on the adjustments for which this
Agreement provides. At least two (2) business days before the Closing Date,
Buyer shall deliver to Sellers a written report proposing and explaining any
changes to the Closing Statement; provided however, if Buyer fails to timely
deliver such report, Sellers' Closing Statement shall conclusively be deemed
accurate, and the Closing Statement shall be the basis for the Purchase Price.
Notwithstanding the foregoing, however, if the total adjustment proposed by
either party is such that such party, if correct, would be entitled to terminate
this Agreement under Section 7(d), then the Closing shall not occur until and
unless the differences are resolved.

         (b) At the Closing, Sellers shall:

                  (i) execute, acknowledge and deliver to Buyer a Quitclaim
Assignment and Bill of Sale ("ASSIGNMENT") of the Assets, in the form attached
hereto as Exhibit C (with Exhibits A and B hereto being attached thereto),
effective as to runs of oil and deliveries of gas as of 7:00 a.m., Mountain Time
on June 1, 2000 ("EFFECTIVE DATE");

                                       14
<PAGE>   18

                  (ii) execute and deliver to Buyer letters in lieu of transfer
orders (or similar documents), in form acceptable to both parties;

                  (iii) execute and deliver to Buyer an affidavit or other
certification (as permitted by the Internal Revenue Code of 1986) having the
form and language as Exhibit E attached hereto, to the effect that Sellers are
not a "foreign person" within the meaning of Section 1445 (or similar
provisions) of the Internal Revenue Code of 1986; and

                  (iv) provide Buyer with Sellers' Officer Certificate having
the form and language of Exhibit D-1 attached hereto.

         (c) At the Closing, Buyer shall:

                  (i) deliver to the Sellers by wire transfer in immediately
available funds, to an account designated by Sellers in a bank located in the
United States, an amount equal to the Purchase Price minus the Deposit, as such
amount may be adjusted in accordance with the terms hereof;

                  (ii) with respect to Assets operated by Sellers, execute and
deliver to Sellers appropriate evidence reflecting change of operator as
required by applicable authorities and such evidence as Sellers may require that
Buyer is qualified with such authorities to succeed Sellers as operator; and

                  (iii) provide Sellers with Buyer's Officer Certificate having
the form and language of Exhibit D-2 attached hereto.

         (d) Within twenty (20) days after Closing, Sellers will deliver to
Buyer the records and other materials described in Section 1(a).

         (e) Following the Closing, with respect to each Oil and Gas Property as
to which Sellers are disbursing proceeds of production attributable to other
parties entitled thereto, Sellers shall:

                  (i) continue to collect proceeds of production during the
month in which Closing occurs and be responsible for making disbursements, in
accordance with their normal procedures (and at normal times), of such proceeds
from production so collected to the parties entitled to same, with any proceeds
from production thereafter collected by Sellers to be promptly forwarded to
Buyer (who shall thereafter account for same to the parties entitled thereto),
and

                  (ii) deliver to Buyer: (A) a copy of their proceeds
distribution list (but Sellers make no warranties or representations, express or
implied, as to the accuracy of such list) for each such Asset (which list shall
include the name, address, social security or tax number, and applicable share
of proceeds from production for each party to whom Sellers are disbursing such
proceeds with respect to such Asset), (B) a list of all parties for whom it is
holding in suspense proceeds from production, (C) a list of all parties for whom
it is holding in any advance payments made by other working interest owners for
operations to be conducted on the Assets, and (D) a check (which shall be
delivered within 30 days after the end of the month in which Closing occurs) in
an amount equal to all suspended funds and advance payments. Following delivery
of the materials referred to in this

                                       15
<PAGE>   19

subsection, Buyer shall be responsible for all disbursements of proceeds from
production (including suspense and other disbursements attributable to periods
prior to the Effective Date) and such disbursement activities shall be included
in the matters which Buyer assumes, and indemnifies Sellers with respect to,
hereunder.

         (f) All production attributable to Sellers' interest in the Oil and Gas
Properties, and all proceeds from the sale thereof, including proceeds from the
sale of any oil in storage above the pipeline connection, and any accounts
receivable balances and related Claims and Damages, any of which are
attributable to production prior to the Effective Date, shall be and remain
Sellers' property. All such production therefrom, and all proceeds from the sale
thereof, attributable to production after the Effective Date shall be Buyer's
property.

         (g) Buyer shall execute, acknowledge and file the Assignment for record
immediately upon receipt thereof and will furnish to Sellers a copy of the
recorded document promptly after Buyer's receipt of such recorded instrument
from the clerk in each county or parish in which the Assignment is recorded. In
addition, where applicable, Buyer shall execute any forms required to effect a
change of operator for all wells conveyed herein.

         (h) Following the Closing, Buyer shall:

                  (i) Promptly take all actions necessary to succeed Sellers as
the party to any leases, rights-of-way, contracts, bonds, permits, licenses, and
any other instrument, and to all duties, obligations, and liabilities to
individuals, private entities, or governmental authorities, with respect to the
Assets to which Sellers were a party or by which it was bound, and protect,
defend, indemnify, and hold Sellers harmless from any and all Claims and Damages
with respect thereto; and

                  (ii) Assume and fully perform all of Sellers' duties,
liabilities and obligations relating to the Assets, including duties,
liabilities, and other obligations imposed by any leases, rights-of-way,
contracts, bonds, permits, licenses, and any other instrument to which Sellers
were a party or by which it was bound, and shall protect, defend, indemnify, and
hold Sellers harmless from any and all Claims and Damages with respect thereto,
including the plugging and abandonment of any wells.

         13. CERTAIN POST-CLOSING ADJUSTMENTS. (a) Following Closing, in the
manner provided in subsection (c), appropriate adjustments shall be made between
Buyer and Sellers so that:

                  (i) all expenses attributable to Sellers' interest in the
Assets that are incurred in the ownership and operation of the Assets before the
Effective Date will be borne by Sellers and all proceeds payable to Sellers for
their interest in the Assets (net of applicable production, severance, and
similar taxes) from the sale of oil, gas and other minerals produced, and the
disposal of produced water therefrom before the Effective Date will be received
by Sellers, and

                  (ii) all expenses attributable to Sellers' interest in the
Assets which are incurred in the ownership and operation of the Assets after the
Effective Date will be borne by Buyer and all proceeds payable to Sellers for
their interest in the Assets (net of applicable production, severance, and
similar taxes) from the sale of oil, gas and other minerals produced therefrom
on and after the Effective Date will be received by Buyer.

                                       16
<PAGE>   20

         (b) In making the adjustments under subsection (a): (i) oil which was
produced from the Oil and Gas Properties and which was, on the Effective Date,
stored in tanks located on the Oil and Gas Properties (or located elsewhere but
used by Sellers to store oil produced from the Oil and Gas Properties prior to
delivery to oil purchasers) and above pipeline connections shall be deemed to
have been produced before the Effective Date, and (ii) ad valorem taxes assessed
with respect to the taxing period in which the Effective Date falls, regardless
of the basis on which such taxes are computed, shall be prorated based on the
number of days in such period which fall on each side of the Effective Date
(with the day on which the Effective Date falls being counted in the period
after the Effective Date), and shall, where the current year's taxes are not yet
known, be based on the previous year's taxes. Each party shall bear their own
local, state or federal income tax liabilities.

         (c) As soon as practicable after Closing, but in any event within
ninety (90) days thereafter, Sellers shall prepare and submit to Buyer a
proposed statement ("FINAL STATEMENT"), which shall show the final calculation
of the Purchase Price ("FINAL SETTLEMENT PRICE"), based on the adjustments for
which this Agreement provides. As soon as possible after receipt of the Final
Statement, but in any event within thirty (30) days after receipt thereof, Buyer
shall deliver to Sellers a written report containing the changes, if any, which
Buyer proposes being made to the Final Statement; provided however, if Buyer
fails to timely deliver such report, Sellers' Final Statement and Final
Settlement Price shall conclusively be deemed accurate, and such Final Statement
shall be the basis for the Final Settlement Price. In the event that Buyer
submits a response, the parties shall exercise all reasonable efforts to agree
with respect to the amounts due not later than ninety (90) days after the
Closing, but in any event prior to September 29, 2000. After agreement upon a
Final Settlement Price setting forth the amount by which the Purchase Price
shall be adjusted (either upward or downward), the amount due shall be paid
within five (5) business days thereafter by the party owing the same in
immediately available funds. Amounts due and payable hereunder, but which are
not paid when due, shall bear interest at the rate of one and one-half percent
per month, compounded monthly, or the maximum amount permitted by law, whichever
is less.

         14. COMMISSIONS. Sellers shall indemnify and hold Buyer harmless from
and against any and all Claims and Damages arising out of or resulting from any
agreement, arrangement or understanding alleged to have been made by, or on
behalf of, Sellers with any broker or finder in connection with this Agreement
or the transaction contemplated hereby. Buyer shall indemnify and hold harmless
Sellers from and against any and all Claims and Damages arising out of or
resulting from any agreement, arrangement or understanding alleged to have been
made by, or on behalf of, Buyer with any broker or finder in connection with
this Agreement or the transaction contemplated hereby.

         15. CASUALTY LOSS. In the event of damage by fire or other casualty to
the Assets prior to the Closing, this Agreement shall remain in full force and
effect, and in such event, unless Buyer and Sellers shall otherwise agree:

         (a) as to each such Asset so damaged that is an Oil and Gas Property,
at Buyer's election either: (i) such Asset shall be treated as if it were
subject to an Asserted Defect, and the procedure provided for in Section 6 shall
be applicable thereto, or (ii) the Purchase Price will not be adjusted, but if
Sellers are entitled to make any claims under any insurance policy with respect
to such

                                       17
<PAGE>   21

damage, Sellers shall, at Sellers' election, either collect (and when collected,
or at the Closing, whichever last occurs, pay over to Buyer), or assign to Buyer
(at the Closing), such claims, and

         (b) as to each such Asset so damaged that is not an Oil and Gas
Property, at Sellers' election it shall either collect for (and when collected,
or at the Closing, whichever last occurs, pay over to Buyer), or assign to Buyer
(at the Closing), any and all insurance claims relating to such loss, and Buyer
shall take title to the Asset affected by such loss without reduction of the
Purchase Price.

         16. NOTICES. All notices, demands or communications ("NOTICES") under
this Agreement shall be in writing and shall be addressed to the party as set
forth below. All Notices shall be given by: (i) personal delivery, (ii)
electronic communication, provided the transmitting device used by the party
provides documentary confirmation of receipt, (iii) first class mail, postage
prepaid, or (iv) a nationally recognized overnight courier service. All Notices
shall be effective and shall be deemed delivered (i) if by personal delivery or
by overnight courier, on the date of delivery if delivered on or before 4:30
p.m. on such day; otherwise, it shall be deemed to have been delivered on the
next business day following delivery, (ii) if by electronic communication, on
the day of receipt unless received after 4:30 p.m., in which event it shall be
deemed to have been received on the next business day following receipt of the
electronic communication, and (iii) if solely by mail, on the first to occur or
actual receipt. A party may change its address by Notice to the other party.

If to Sellers:

         Tipperary Oil & Gas Corporation       Burro Pipeline Corporation
         633 17th Street, Suite 1550           633 17th Street, Suite 1550
         Denver, Colorado   80202              Denver, CO 80202
         Attention: David L. Bradshaw          Attention: David L. Bradshaw
         Telephone No.: (303) 293-9379         Telephone No.: (303) 293-9379
         Facsimile No.:  (303) 292-3428        Facsimile No.: (303) 292-3428

If to Buyer:

         Transrepublic Resources, Inc.
         415 West Wall, Suite 703
         Midland, Texas 79701
         Attention: R. F. Bailey
         Telephone No.: (915) 686-9869
         Facsimile No.:  (915) 683-1649

         17. SURVIVAL OF PROVISIONS. The parties' respective covenants
(including indemnification obligations) that are to be performed after the
Closing or that may otherwise be applicable following the Closing, and the
parties' respective warranties and representations (and disclaimers of
warranties, representations, and covenants), shall survive the Closing and shall
not merge into the Assignment or into any other documents or other instruments
executed in connection herewith. Consistent with, but not as a limitation on the
foregoing, the parties' respective obligations under Sections 1(b), 2(c), 3, 4,
6(a)(iii)(B), 6(b)(i)(A), 6(b)(ii)(B), 6(e), 7(e), 8, 11(c), 12(d), 12(e),
12(h), 13(c), 14, 16, 17, 18, 19-26, 29, and 31 shall survive the Closing and
the delivery of the Assignment.

                                       18
<PAGE>   22

         18. OPERATIONS. Subject to the terms and provisions of any existing
agreements covering the Assets, Sellers agree to turn over to Buyer, at Closing,
the operations of those Assets for which it is currently serving as operator.
Sellers shall take all reasonable actions necessary to attempt to cause Buyer to
become successor operator as contemplated herein.

         19. CONFIDENTIALITY AGREEMENT. The Confidentiality Agreement shall
terminate only if and after Closing occurs and the Assignment is executed and
delivered.

         20. FURTHER ASSURANCES. Without further consideration, each party shall
take such further actions and execute such further documents as may be
reasonably requested by the other party in order to effectuate the purpose and
intent of this Agreement, including (if Closing occurs) division orders,
transfer orders and other documents.

         21. GOVERNING LAW, AND VENUE. (a) This Agreement shall be: (i) deemed
to have been negotiated, executed, and performed in Colorado, and (ii) governed
by and interpreted in accordance with the Laws of Colorado, including the Laws
of Colorado pertaining to conflict of law and choice of law; provided however,
that it is the parties' intent that the Laws of Colorado, without regard to its
conflict of law or choice of law rules, shall govern to the greatest extent.

         (b) Venue for the resolution of any disputes hereunder shall be limited
to federal or state courts of competent jurisdiction sitting in Colorado, and
the parties shall not challenge the subject matter or personal such jurisdiction
of such courts; provided however, that if and to the extent that governing Law
requires that proceedings be conducted in the state in which the property is
situated, then notwithstanding the foregoing, such proceedings shall be
commenced and prosecuted in a court of competent jurisdiction in such state, and
any ancillary proceedings shall be consolidated with such proceedings. If a
party does not have a registered agent for service of process in such state,
then for purposes hereof, service of process may be accomplished in such other
manner as may be provided by Law for service upon entities that are required to
have a registered agent in such state but that do not have a registered agent.

         22. COSTS. Except as may be expressly provided otherwise herein, each
party shall bear their own costs and expenses in connection with the negotiation
and performance of this Agreement.

         23. ENTIRE AGREEMENT; AMENDMENT; AND WAIVER. (a) This Agreement, which
includes any and all exhibits, contains the entire understanding and agreement
of the parties and supersedes all prior agreements and understandings between
the parties relating to the subject matter hereof.

         (b) No amendment or modification to this Agreement shall be effective
unless be in writing and signed by all parties. Consistent with but not as a
limitation on the foregoing, references in this Agreement to the parties
attempting to agree, or unless otherwise agreed, or phrases of similar import,
shall mean and require agreements reduced to writing.

         (c) No waiver by a party of any breach by the other party of any
provision of this Agreement shall be deemed a waiver of any preceding or
succeeding breach of the same or any other provisions hereof. No such waiver
shall be effective unless in writing and then only to the extent expressly set
forth in writing.

                                       19
<PAGE>   23

         24. SECTION AND OTHER HEADINGS; AND CONSTRUCTION. The section and other
headings contained in this Agreement are for reference only and have no legal
significance. The use of pronouns is generic and they shall mean any gender as
appropriate. The terms "include," "including," or similar terminology shall be
construed as meaning without limitation as to the nature or scope of the
referenced matters, whether similar or dissimilar to the referenced matters. The
terms "herein" or "hereof," or similar terminology, shall be construed as
referring to this Agreement rather than only the section or subsection in which
such term appears. References to subsections shall refer to the section in which
they appear, unless otherwise noted. This Agreement shall be deemed to have been
drafted by both parties, and therefore the rule against construing ambiguities
against the party drafting a contract shall be inapplicable to this Agreement.

         25. SEVERABILITY. If any provision of this Agreement is held to be
invalid or unenforceable in whole or in part in any relevant jurisdiction, such
provision, only to the extent invalid or unenforceable, shall be severable from
this Agreement, and the other provisions of this Agreement (along with the
provision at issue, to the extent that it would be valid and enforceable, and
such provision shall be deemed to be so reformed) shall remain in full force and
effect in such jurisdiction and the remaining provisions hereof shall be
liberally construed to carry out the purpose and intent of this Agreement. The
invalidity or unenforceability, in whole or in part, of any provision of this
Agreement in any relevant jurisdiction shall not affect the validity or
enforceability of such provision in any other jurisdiction, nor shall the
invalidity or unenforceability of any provision of this Agreement with respect
to any Person affect the validity or enforceability of such provision with
respect to any other Person.

         26. ATTORNEY'S FEES. If litigation is commenced between the parties,
the prevailing party shall be entitled to recover from the other party all
reasonable attorney fees and costs. The prevailing party shall include: a party
who dismisses an action in exchange for sums allegedly due; the party who
received performance from the other party for an alleged breach of contract or a
desired remedy where the performance is substantially equal to the relief sought
in an action; or the party determined to be the prevailing party by a court of
law.

         27. RESTRICTIONS ON ASSIGNMENT. Neither party may assign its rights
under this Agreement and any such assignment in violation of this provision
shall be void; provided however, that notwithstanding the foregoing, Buyer and
Sellers may assign their rights under this Agreement to a subsidiary or other
affiliate.

         28. TIME OF THE ESSENCE. Time is of the essence of this Agreement. If
the last day permitted for the performance of any act required or permitted
under this Agreement falls on a Saturday, Sunday, or holiday, the time for such
performance shall be extended to the next succeeding business day.

         29. PARTIES IN INTEREST; SUCCESSORS AND ASSIGNS. This Agreement shall
be binding upon and inure to the benefit of and be enforceable by the successors
and permitted assigns of Sellers or Buyer. Nothing in this Agreement is intended
to confer upon any other person or entity any rights or remedies under or by
reason of this Agreement.

                                       20
<PAGE>   24

         30. NO PUBLICITY. Buyer shall not issue any publicity or press release
concerning this Agreement or the transaction contemplated hereby without the
prior written consent of Sellers, unless, in the written opinion of legal
counsel acceptable to Sellers, such disclosure is required by applicable law or
other applicable rules or regulations of any governmental authority or stock
exchange and such publicity or press release contains no more than the minimum
information necessary to comply therewith. This provision shall not replace or
restrict any provision in any prior agreement between the parties affecting
confidentiality or the disclosure of information about the Assets.

         31. NO RECORDING. This Agreement shall not be recorded by either party
without the prior consent of the other party.

         32. INDEMNIFICATION. With respect to the portion, if any, of the oil
and gas properties situated in the State of New Mexico, and to the extent that
Section 56-7-1 NMSA 1978 (1995 Repl.) may be applicable to this purchase and
sale agreement, any indemnity agreement contained herein shall not extend to
liability, claims, damages, losses, or expenses, including attorney's fees
arising out of:

         (i) The preparation or approval of maps, drawings, opinions, reports,
surveys, change orders, designed, or specifications by the indemnitee, or the
agents or employees of the indemnitee; or

         (ii) The giving of or the failure to give directions or instructions by
the indemnitee, or the agents or the employees of the indemnitee, where such
giving or failure to give such directions or instructions is the primary cause
of bodily injury to persons or damages to property.

         33. TAX ALLOCATION. Sellers and Buyer shall use their best efforts to
agree on an allocation for purposes of Form 8594, Asset Acquisition Statement
within 30 days after Closing. If the parties are unable to agree on such an
allocation in a timely manner, the parties will, by amended tax returns and
claims for refunds, make its best efforts to have the required informational
reports agree.

         IN WITNESS WHEREOF, this Agreement is executed by the parties hereto on
the date set forth above.

SELLERS:                                    BUYER:

TIPPERARY OIL & GAS CORPORATION             TRANSREPUBLIC RESOURCES, INC.

By:                                         By:
    -------------------------------------       --------------------------------
    David L. Bradshaw                           R. F. Bailey
    President and Chief Executive Officer       President

                                       21
<PAGE>   25

BURRO PIPELINE CORPORATION

By:
    ----------------------------------------
    David L. Bradshaw
    President and Chief Executive Officer

                                       22
<PAGE>   26

                                                     PURCHASE AND SALE AGREEMENT
                                     BETWEEN TIPPERARY OIL & GAS CORPORATION AND
                                                      BURRO PIPELINE CORPORATION
                                               AND TRANSREPUBLIC RESOURCES, INC.

                                   EXHIBIT "C"

                      QUITCLAIM ASSIGNMENT AND BILL OF SALE

         THIS QUITCLAIM ASSIGNMENT AND BILL OF SALE ("ASSIGNMENT"), dated
_______, 2000, is between Tipperary Oil & Gas Corporation, a Texas corporation,
and Burro Pipeline Corporation, a New Mexico corporation ("ASSIGNORS"), the
address of which is 633 17th Street, Suite 1550, Denver, Colorado 80202, and
Transrepublic Resources, Inc., a Texas corporation ("ASSIGNEE"), the address of
which is 415 West Wall, Suite 703, Midland, Texas 79701.

                                    RECITALS:

         A. The parties entered into that certain Purchase and Sale Agreement
dated June 12, 2000 ("AGREEMENT"), pursuant to which Assignors agreed to sell,
assign, and convey, and Assignee agreed to purchase the hereinafter described
Assets.

         B. The parties have consummated the purchase and sale of the Assets
pursuant to the Agreement, and this Assignment is being executed and delivered
pursuant thereto.

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

         1. CONVEYANCE AND RESERVATION. (a) Assignors do hereby quitclaim and
sell unto Assignee the following described properties, rights and interests
(collectively, "ASSETS"), but only to the extent related to the real property
described in Exhibit A ("PROPERTY"):

                  (i) All of Assignors' right, title, and interest, if any, in
all oil, gas and other mineral interests, including Assignors' right, title, and
interest, if any, in all: (A) oil and gas leases and any other mineral leases
and related easements and rights-of-way, (B) royalties and overriding royalties,
(C) production payments, (D) net profits interests, (E) reversionary mineral
interests, (F) unitization, pooling, and communitization agreements, and (G)
declarations and orders (including all units formed under orders, rules,
regulations, or other official acts of any federal, state, or other authority
having jurisdiction, and voluntary unitization agreements, designations and
declarations), subject to any exceptions and reservations contained in Exhibit
A;

                  (ii) All of Assignors' right, title, and interest, if any, in
all fixtures, equipment, and other personal property, to the extent relating to
the wells described in Exhibit B, situated on the Property; and

                  (iii) all contracts; lease files; abstracts and title
opinions; production records; well files; permits and licenses; accounting
records (but excluding all general financial accounting or tax accounting
records that do not pertain exclusively to the Property); electric logs and
geological,

                                        1
<PAGE>   27

engineering, and other technical data and records (subject to any contractual or
other restrictions relating to the transfer of such data and records); and other
files, documents and records that directly relate to the Property.

                  (b) Assignors' interest, if any, in the assets described in
subsection (a) is herein sometimes collectively called the "ASSETS."

         (c) Assignors except and reserve from this Assignment, a concurrent
right to utilize any easements or right-of-way rights in and to the surface
estate of the property and all rights of any nature whatsoever appurtenant or
otherwise associated therewith, and such right, title, and interest does not
constitute any part of the Assets. The reservation of these concurrent rights
shall be in addition to and not limit the statutory, contractual, or common law
rights of Buyer to use the surface estate for the development of Oil and Gas
property described herein.

         (d) As of the effective date hereof, Assignee assumes all of Assignors'
duties, liabilities and obligations relating to the Assets, and shall protect,
defend, indemnify, and hold Assignors harmless from any and all rights, claims,
demands, causes of action, and legal, administrative, or arbitration
proceedings, of any and every nature (collectively, "CLAIMS"), and injuries,
deaths, damages, and obligations of any and every nature resulting from or that
gave rise to any Claim, including liabilities, losses, costs, penalties,
expenses, judgments, fines, settlements, interest, reasonable attorney's fees,
and other related expenses of any nature (collectively, "DAMAGES") with respect
thereto; provided however, that Damages shall not include consequential,
special, incidental, or punitive damages.

         (e) Assignors reserve the right to continue, at no cost to Assignors,
disposing of produced water from field remediation operations, into the O. G.
State No. 2 disposal well.

         2. DISCLAIMER OF WARRANTIES. (a) Assignors make no warranty,
representation, or covenant, express or implied, as to their title to the
Assets, and Assignors make no other warranty, representation, or covenant,
express or implied, with respect to the Assets.

         (b) CONSISTENT WITH AND NOT AS A LIMITATION ON SUBSECTION (a), THE
ASSETS ARE HEREBY PURCHASED, SOLD, AND CONVEYED "AS IS, WHERE IS", WITHOUT ANY
WARRANTY, REPRESENTATION, OR COVENANT, EXPRESS OR IMPLIED, STATUTORY OR
OTHERWISE, RELATING TO:

                  (i) THE CONDITION, QUANTITY, QUALITY, FITNESS FOR A PARTICULAR
PURPOSE OR ANY PURPOSE, CONFORMITY TO THE MODELS OR SAMPLES OF MATERIALS, OR
MERCHANTABILITY OF ANY IMMOVABLE PROPERTY, MOVABLE PROPERTY, EQUIPMENT,
INVENTORY, MACHINERY, AND OTHER FIXTURES AND PERSONAL PROPERTY CONSTITUTING PART
OF THE ASSETS;

                  (ii) ANY IMPLIED OR EXPRESS WARRANTY OF FREEDOM FROM
REDHIBITORY VICES OR DEFECTS OR OTHER VICES OR DEFECTS, WHETHER KNOWN OR
UNKNOWN; AND

                                        2
<PAGE>   28

                  (iii) ANY AND ALL IMPLIED WARRANTIES, REPRESENTATIONS, OR
COVENANTS EXISTING UNDER APPLICABLE LAW NOW OR HEREAFTER IN EFFECT.

         (c) CONSISTENT WITH BUT NOT AS A LIMITATION ON SUBSECTIONS (a) AND (b):

                  (i) ASSIGNORS ARE SELLING AND ASSIGNEE IS BUYING THE ASSETS
WITH ALL DEFECTS AND FAULTS (LATENT OR APPARENT) AND IT ASSUMES THE RISK THAT
ADVERSE PAST, PRESENT OR FUTURE PHYSICAL CONDITIONS MAY NOT HAVE BEEN REVEALED
BY THEIR INVESTIGATIONS, AND

                  (ii) ASSIGNORS MAKE NO WARRANTY OR REPRESENTATION, EXPRESS OR
IMPLIED, STATUTORY OR OTHERWISE, AS TO THE ACCURACY OR COMPLETENESS OF ANY DATA,
REPORTS, RECORDS, PROJECTIONS, INFORMATION, OR OTHER MATERIALS NOW HERETOFORE,
OR HEREAFTER FURNISHED OR MADE AVAILABLE TO ASSIGNEE IN CONNECTION HEREWITH,
INCLUDING PRICING ASSUMPTIONS OR QUALITY OR QUANTITY OF HYDROCARBON RESERVES (IF
ANY) ATTRIBUTABLE TO THE ASSETS OR THE ABILITY OR POTENTIAL OF THE ASSETS TO
PRODUCE HYDROCARBONS OR THE ENVIRONMENTAL CONDITION OF THE ASSETS OR ANY OTHER
MATERIALS FURNISHED OR MADE AVAILABLE TO ASSIGNEE BY OR ON BEHALF OF ASSIGNORS.

         3. SUBJECT TO AGREEMENT. This Assignment is subject to the terms of the
Agreement, which terms are incorporated herein by this reference, survive the
execution and delivery of, and have not merged into, this Agreement, and are
binding on Assignors and Assignee and their respective successors and assigns.
Such provisions of the Agreement include, without limitation, additional
warranties and representations of the parties. If the Agreement and the
Assignment conflict, the Agreement controls.

         4. COUNTERPARTS. This Assignment may be executed in several
counterparts all of which are identical, except that, to facilitate recordation,
in certain counterparts hereof, only that portion of Exhibit A that contains
specific descriptions of assets located in the recording jurisdiction in which
the particular counterpart is to be recorded are included, and other portions of
Exhibit A are included by reference only. All such counterparts together shall
constitute one and the same instrument. Complete copies of this Assignment
containing the entire Exhibit A have been retained by Assignors and Assignee.

         IN WITNESS WHEREOF, this Assignment has been executed and delivered on
the date first set out above, but effective as to runs of oil and deliveries of
gas, and for all other purposes, as of 7:00 a.m., local time at the locations of
the Assets, on June 1, 2000.

                                       3
<PAGE>   29

ASSIGNORS:                                  ASSIGNEE:

TIPPERARY OIL & GAS CORPORATION             TRANSREPUBLIC RESOURCES, INC.

By:                                         By:
    -------------------------------------       --------------------------------
    Jeff T. Obourn                              R. F. Bailey
    Sr. Vice President - Operations             President

BURRO PIPELINE CORPORATION

By:
    -------------------------------------
    Jeff T. Obourn
    Sr. Vice President - Operations

                                 ACKNOWLEDGMENTS

STATE OF COLORADO          )
                           )ss
City and County of Denver  )

         On this ___ day of ___________, 2000, before me, a Notary Public of
said state, duly commissioned and sworn, appeared Jeff T. Obourn, known to me to
be the person whose name is subscribed to the within instrument as Sr. Vice
President - Operations of Tipperary Oil & Gas Corporation, a Texas corporation,
and acknowledged to me that such corporation executed the same.

         Witness my hand and official seal.

                                        ----------------------------------------
                                        Notary Public, State of Colorado

My commission expires:
                      -------------------------------------

                                       4
<PAGE>   30

STATE OF COLORADO          )
                           )ss
City and County of Denver  )

         On this ___ day of ___________, 2000, before me, a Notary Public of
said state, duly commissioned and sworn, appeared Jeff T. Obourn, known to me to
be the person whose name is subscribed to the within instrument as Sr. Vice
President - Operations of Burro Pipeline Corporation, a New Mexico corporation,
and acknowledged to me that such corporation executed the same.

         Witness my hand and official seal.

                                        ----------------------------------------
                                        Notary Public, State of Colorado

My commission expires:
                      -------------------------------------

STATE OF ____________      )
                           )ss
County of _____________    )

         On this ___ day of ____________, 2000, before me, a Notary Public of
said state, duly commissioned and sworn, appeared R. F. Bailey, known to me to
be the person whose name is subscribed to the within instrument, as President of
Transrepublic Resources, Inc., a Texas corporation, and acknowledged to me that
such corporation executed the same.

Witness my hand and official seal.

                                        ----------------------------------------
                                        Notary Public, State of
                                                               -----------------

My commission expires:
                      -------------------------------------

                                       5
<PAGE>   31

                                                     PURCHASE AND SALE AGREEMENT
                                     BETWEEN TIPPERARY OIL & GAS CORPORATION AND
                                                      BURRO PIPELINE CORPORATION
                                               AND TRANSREPUBLIC RESOURCES, INC.

                                   EXHIBIT "D"

Iva Com                                     20H-11S-33E

Mable Com                                   29A-11S-33E

Bell A                                      21C-11S-33E

State NBF                                   22F-11S-33E

Sohio 1                                     4P-11S-33E

Sohio A                                     4O-11S-33E

GS State                                    8G-11S-33E

Sat 4                                       12I-11S-33E

Collier                                     9F-11S-33E

                                       1
<PAGE>   32

                                                     PURCHASE AND SALE AGREEMENT
                                     BETWEEN TIPPERARY OIL & GAS CORPORATION AND
                                                      BURRO PIPELINE CORPORATION
                                               AND TRANSREPUBLIC RESOURCES, INC.

                                  EXHIBIT "D-1"

                              OFFICER'S CERTIFICATE

         TIPPERARY OIL & GAS CORPORATION, a Texas corporation, ("SELLER"), the
address of which is 633 17th Street, Suite 1550, Denver, Colorado 80202, with
respect to that certain Purchase and Sale Agreement dated June 15, 2000
("AGREEMENT"), between Seller and Transrepublic Resources, Inc., a Texas
corporation ("BUYER"), hereby certifies that: (i) Seller has materially complied
with and performed all obligations pertaining to Seller, to be performed prior
to the Closing, except for those waived by Buyer, and (ii) all of Seller's
warranties and representations in the Agreement remain true and correct as of
the date hereof, the same as if made as of the date hereof.

         Executed as of this      day of                    , 2000.
                             ----        -------------------

                                     Seller:

                                     TIPPERARY OIL & GAS CORPORATION

                                     By:
                                          --------------------------------------
                                          Jeff T. Obourn
                                          Sr. Vice President - Operations

                                       1
<PAGE>   33

                                                     PURCHASE AND SALE AGREEMENT
                                     BETWEEN TIPPERARY OIL & GAS CORPORATION AND
                                                      BURRO PIPELINE CORPORATION
                                               AND TRANSREPUBLIC RESOURCES, INC.

                                  EXHIBIT "D-1"

                              OFFICER'S CERTIFICATE

         BURRO PIPELINE CORPORATION, a New Mexico corporation, ("SELLER"), the
address of which is 633 17th Street, Suite 1550, Denver, Colorado 80202, with
respect to that certain Purchase and Sale Agreement dated June 15, 2000
("AGREEMENT"), between Seller and Transrepublic Resources, Inc., a Texas
corporation ("BUYER"), hereby certifies that: (i) Seller has materially complied
with and performed all obligations pertaining to Seller, to be performed prior
to the Closing, except for those waived by Buyer, and (ii) all of Seller's
warranties and representations in the Agreement remain true and correct as of
the date hereof, the same as if made as of the date hereof.

         Executed as of this      day of                    , 2000.
                             ----        -------------------

                                     Seller:

                                     BURRO PIPELINE CORPORATION

                                     By:
                                          --------------------------------------
                                          Jeff T. Obourn
                                          Sr. Vice President - Operations

                                       1
<PAGE>   34

                                                     PURCHASE AND SALE AGREEMENT
                                     BETWEEN TIPPERARY OIL & GAS CORPORATION AND
                                                      BURRO PIPELINE CORPORATION
                                               AND TRANSREPUBLIC RESOURCES, INC.

                                  EXHIBIT "D-2"

                              OFFICER'S CERTIFICATE

         TRANSREPUBLIC RESOURCES, INC., a Texas corporation ("BUYER"), the
address of which is 415 West Wall, Suite 703, Midland, Texas 79701, with respect
to that certain Purchase and Sale Agreement dated June 12, 2000 ( "AGREEMENT"),
between Buyer and TIPPERARY OIL & GAS CORPORATION, a Texas corporation, and
BURRO PIPELINE CORPORATION, a New Mexico corporation ("SELLERS"), the address of
which is 633 17th Street, Suite 1550, Denver, Colorado 80202, hereby certifies
that: (i) Buyers have materially complied with and performed all obligations
pertaining to Buyer, to be performed prior to the Closing, except for those
waived by Sellers, and (ii) all of Buyer's warranties and representations in the
Agreement remain true and correct as of the date hereof, the same as if made as
of the date hereof.

         Executed as of this      day of                    , 2000.
                             ----        -------------------

                                     BUYER:

                                     TRANSREPUBLIC RESOURCES, INC.

                                     By:
                                          --------------------------------------
                                          R. F. Bailey
                                          President

                                       2
<PAGE>   35

                                                     PURCHASE AND SALE AGREEMENT
                                     BETWEEN TIPPERARY OIL & GAS CORPORATION AND
                                                      BURRO PIPELINE CORPORATION
                                               AND TRANSREPUBLIC RESOURCES, INC.

                                   EXHIBIT "E"

                              NON-FOREIGN AFFIDAVIT
                        EXEMPTION FROM WITHHOLDING OF TAX
                                       FOR
                  DISPOSITIONS OF U.S. REAL PROPERTY INTERESTS

         Section 1445 of the Internal Revenue Code provides that a transferee of
a U.S. real property interest must withhold tax if the transferor is a foreign
person. To inform Transrepublic Resources, Inc., that withholding tax is not
required upon the disposition of U.S. real property interests by Tipperary Oil &
Gas Corporation and Burro Pipeline Corporation, the undersigned hereby certifies
the following:

1.       Tipperary Oil & Gas Corporation and Burro Pipeline Corporation are not
         nonresident alien, foreign corporations, foreign partnerships, foreign
         trusts, or foreign estates for purposes of U.S. income tax;

2.       That taxpayer identifying number of Tipperary Oil & Gas Corporation is
         75-1446759 and Burro Pipeline Corporation is 75-1245236; and

3.       The office address of the financial headquarters of Tipperary Oil & Gas
         Corporation and Burro Pipeline Corporation is 633 17th Street, Suite
         1550, Denver, Colorado 80202.

         Tipperary Oil & Gas Corporation and Burro Pipeline Corporation
understand that this certification may be disclosed to the Internal Revenue
Service by Transrepublic Resources, Inc., or its affiliates or parent, and that
any false statement contained herein could be punished by fine, imprisonment, or
both.

         Under penalties of perjury, I declare that I have examined this
certification and, to the best of my knowledge and belief, it is true, correct,
complete, and further declare I have authority to sign this document.

TIPPERARY OIL & GAS CORPORATION

By:
         ---------------------------------------
         David L. Bradshaw
         President and Chief Executive Officer

         SUBSCRIBED AND SWORN TO by said ________________________________ before
me this _____ day of _____________________, 2000, to certify which witness my
hand and seal of office.

                             ----------------------------------------------
                             Notary Public in and for the State of Colorado

                                       1
<PAGE>   36

BURRO PIPELINE CORPORATION

By:
         ---------------------------------------
         David L. Bradshaw
         President and Chief Executive Officer

         SUBSCRIBED AND SWORN TO by said ________________________________ before
me this _____ day of _____________________, 2000, to certify which witness my
hand and seal of office.

                             ----------------------------------------------
                             Notary Public in and for the State of Colorado

                                       2<PAGE>   1
                                                                   EXHIBIT 10.76

                    TIPPERARY OIL & GAS (AUSTRALIA) PTY. LTD.
                                (ACN 077 536 871)

                                       And

                             ENERGEX RETAIL PTY LTD
                                (ACN 078 849 055)

                              GAS SUPPLY AGREEMENT

                                                                        MAY 2000

<PAGE>   2

<TABLE>
<CAPTION>

   TABLE OF CONTENTS
   <S>   <C>                                                                                                    <C>
   1.    INTERPRETATION........................................................................................5
      1.1   Definitions........................................................................................5
      1.2   General............................................................................................7
      1.3   Headings...........................................................................................9
      1.4   Business Day.......................................................................................9
   2     RELATIONSHIP OF THE PARTIES...........................................................................9
      2.1   Separate Agreement with the Sellers................................................................9
      2.2   Several Liability..................................................................................9
      2.3   Parties Not Released...............................................................................9
      2.4   Common Stream......................................................................................9
   3.    TITLE TO CONTRACT GAS.................................................................................9
   4.    DELIVERY.............................................................................................10
   5.    SPECIFICATIONS.......................................................................................10
   6.    QUANTITY AND PROCEDURES FOR THE SUPPLY OF CONTRACT GAS...............................................10
      6.1   Contract Quantities...............................................................................10
      6.2   Reduction of MDQ by Buyer.........................................................................11
      6.3   Reduction of MDQ by Sellers.......................................................................12
      6.4   Nominations.......................................................................................13
      6.5   Make up Gas.......................................................................................14
      6.6   Field Failure Event...............................................................................14
   7.    DEDICATION OF RESERVES AND COMMITMENT TO DRILL.......................................................15
   8.    MEASUREMENT OF VOLUMES AND REGULATION OF PRESSURES...................................................15
   9.    CONTRACT PRICE.......................................................................................16
   10.   BILLING AND METHOD OF PAYMENT........................................................................17
      10.1  Monthly Statement.................................................................................17
      10.2  Reconciliation Period Statement...................................................................17
      10.3  Payment...........................................................................................17
      10.4  Rebate by Sellers to Buyer........................................................................18
      10.5  Interest..........................................................................................18
      10.6  Disputed Statement................................................................................18
   11.   FORCE MAJEURE........................................................................................18
      11.1  Definition........................................................................................18
      11.2  Consequences of Force Majeure.....................................................................19
      11.3  Notification and Diligence........................................................................20
      11.4  Liability Not Relieved............................................................................20
      11.5  Prolonged Force Majeure...........................................................................21
   12.   TERM OF AGREEMENT....................................................................................21
   13.   DEFAULT..............................................................................................21
   14.   ASSIGNMENT...........................................................................................21
      14.1  Assignment by Buyer...............................................................................21
      14.2  Assignment by the Sellers.........................................................................22
   15.   WARRANTIES...........................................................................................22
   16.   CONDITIONS PRECEDENT.................................................................................22
   17.   DAMAGES..............................................................................................23
   18.   AUDITING.............................................................................................23
   19.   CONFIDENTIALITY......................................................................................23
   20.   ENTIRE AGREEMENT.....................................................................................24
   21.   CESSATION OF INDIVIDUAL CLAUSES......................................................................24
   22.   LAW AND DISPUTE RESOLUTION...........................................................................24
      22.1  Jurisdiction......................................................................................24
   23.   AMENDMENTS...........................................................................................25
   24.   NOTIFICATION.........................................................................................25
      24.1  Giving of Notices.................................................................................25
      24.2  Timing of Receipt.................................................................................25
      24.3  Addresses.........................................................................................26
   25    TERMINATION..........................................................................................27
   26.   COUNTERPARTS.........................................................................................28

SCHEDULE  1...................................................................................................29
</TABLE>

                                       2
<PAGE>   3

<TABLE>

<S>                                                                                                            <C>
   CONTRACT PRICE.............................................................................................29

SCHEDULE  2...................................................................................................30

   SPECIFICATIONS.............................................................................................30

SCHEDULE  3...................................................................................................32

   METERING METHOD SCHEDULE...................................................................................32

SCHEDULE  4...................................................................................................33

   CONTRACT AREAS.............................................................................................33

SCHEDULE 5....................................................................................................34

   OWNERSHIP PERCENTAGE.......................................................................................34

SCHEDULE 6....................................................................................................35

   MAXIMUM DAILY QUANTITY.....................................................................................35
</TABLE>

                                       3
<PAGE>   4

                               GAS SALES AGREEMENT

THIS AGREEMENT is made the                   day of                        2000

BETWEEN:

         Those parties whose names are set out in Schedule 5 (herein called the
         "Sellers")

AND

         ENERGEX Retail Pty Ltd (ACN 078 849 055) having offices at 150
         Charlotte St, Brisbane, Queensland, 4000 ( herein called the "Buyer").

RECITALS

A.       The Sellers have represented to Buyer that, to the knowledge of the
         Sellers, they intend to develop sufficient Contract Gas resources based
         on coal seam methane, possess the necessary expertise and have entered
         into all necessary binding transportation and delivery agreements with
         transporters of Contract Gas to safely supply Buyer's Contract Gas
         requirements to the Delivery Point.

B.       Buyer trades gas in the Queensland gas market.

C.       Buyer wishes to purchase certain quantities of Contract Gas from the
         Sellers, each of whom is willing to sell its Ownership Percentage of
         those quantities of Contract Gas to the Buyer.

D.       In reliance on the representations in Recital A. Buyer is entering into
         this Agreement with the Sellers to set out the terms and conditions
         under which the purchase and sale of Contract Gas may take place.

E.       Buyer acknowledges that, in performing its obligations under this
         Agreement, it is acting as the agent of Allgas Energy Ltd (ACN 009 656
         446).

F.       The Sellers warrant that they have documented approval from the TCW
         Asset Management Company for funding sufficient to implement the
         minimum twenty well field development program on ATP526P.

                                       4
<PAGE>   5

THE PARTIES AGREE AND DECLARE AS FOLLOWS:

1.      INTERPRETATION

1.1      DEFINITIONS

         In this agreement, unless the context otherwise requires:

         "AGREEMENT" means this agreement as may be amended from time to time
         together with its schedules, annexures and attachments;

         "BUSINESS DAY" means any day of the week except Saturdays, Sundays and
         days which have been declared as public holidays by the government of
         Queensland;

         "COAL SEAM METHANE" means hydrocarbons in a gaseous state occurring in
         association with coal;

         "COMMENCEMENT DATE" means 1 June 2000;

         "CONTRACT AREA" means the areas described in Schedule 4

         "CONTRACT GAS" means:

         (a)      Coal Seam Methane which meets the Specification; or

         (b)      Off Specification Gas which is delivered and accepted by Buyer
                  in accordance with the provisions of clause 4;

         "CONTRACT PRICE" has the meaning ascribed to it in clause 9;

         "CONTRACT YEAR" means a period commencing at 8.00am on the Commencement
         Date and ending at 8.00am, on the first anniversary of the Commencement
         Date and thereafter each successive period of 12 consecutive months;

         "CUBIC METRE" or "M3" means the amount of Contract Gas which occupies
         one cubic metre when that Contract Gas is at Standard Conditions;

         "DAILY NOMINATION" means, for a particular Day, the quantity of
         Contract Gas, not exceeding MDQ, which Buyer has nominated, pursuant to
         clause 6, for delivery on that Day;

         "DAY" means a period of twenty four (24) consecutive hours, which
         begins and ends at 8.00 am in the morning;

         "DELIVERY POINT" means the inlet flange into the Duke Queensland Gas
         Pipeline or any other point agreed between the Buyer and the Sellers,
         provided that no additional costs shall be incurred by either Party and
         provided that agreement shall not be unreasonably withheld;

                                       5
<PAGE>   6

         "DISPOSE" means assign, transfer or otherwise dispose of any legal or
         equitable interest, either in whole or part, whether by sale, lease,
         declaration or creation of a trust or otherwise but does not include
         grant of a security interest;

         "DUKE QUEENSLAND GAS PIPELINE" means the natural gas pipeline referred
         to in Pipeline Licence No 30;

         "FIELD OPERATOR" means the company or organisation who has
         responsibility for the day to day operations of the Contract Area
         defined in Schedule 4.;

         "FIRST AGREEMENT" means the Gas Supply Agreement between Allgas Energy
         Ltd and Tipperary Oil and Gas (Australia) Pty Ltd dated 8 September
         1998;

         "FORCE MAJEURE" has the meaning given in clause 11;

         "GAS ACT" means the Gas Act (Queensland) 1965;

         "GJ" means one gigajoule (1,000,000,000 joules);

         "GROSS HEATING VALUE" and "GHV" mean the energy produced by the
         complete combustion of one Cubic Metre of Contract Gas with air, at an
         absolute pressure of 101.325 kPa and temperature of fifteen (15)
         degrees Celsius, with the Contract Gas and air free of all water
         vapour, the product of combustion cooled to a temperature of fifteen
         (15) degrees Celsius and the water vapour formed by combustion
         condensed to the liquid state, expressed in MJ per Cubic Metre (MJ/m3);

         "INTEREST RATE" refers to a rate of interest that is one percent above
         the ANZ Banking Group Reference Rate;

         "MAKE UP GAS" means that portion of the quantity of Contract Gas which
         Buyer has paid for but not taken in the relevant Month , and where the
         context so requires, means the aggregate of such quantities of Contract
         Gas credited to Buyer in respect of prior Months less any quantities of
         Contract Gas taken by Buyer pursuant to clause 6.5.1;

         "MAXIMUM DAILY QUANTITY" or "MDQ" means the maximum quantity of
         Contract Gas which Buyer can require the Sellers to deliver to the
         Delivery Point on any given Day, subject to clauses 6.2 & 6.3, as set
         out in Schedule 6.

         "MINIMUM MONTHLY QUANTITY" means that quantity of Contract Gas
         calculated by aggregating for each Month, the quantity of Contract Gas
         equivalent to fifty (50) per cent of the MDQ applicable for each Day of
         that Month;

         "MJ" means one megajoule (1,000,000 joules);

         "MONTH" means a period beginning at 8.00 am on the morning of the first
         day of the calendar month and ending at 8.00 am on the morning of the
         first Day of the succeeding calendar Month;

         "OFF-SPECIFICATION GAS" means Coal Seam Methane which does not conform
         to the Specifications;

                                       6
<PAGE>   7

         "OWNERSHIP PERCENTAGE" means the Ownership Percentage of the Sellers as
         set out in Schedule 5, as may be varied from time to time in accordance
         with the provisions of this Agreement;

         "PARTY" means either Seller or Buyer as the context may require and
         "PARTIES" shall mean both the Sellers and Buyer;

         "PJ" means one petajoule (1,000,000 GJ);

         "RECONCILIATION PERIOD" means a period commencing at 8.00 am on the
         Commencement Date and ending at 8.00 am on the Day six (6) Months later
         and thereafter each successive period of six (6) consecutive Months;

         "RELATED CORPORATION" A body corporate that is a related body corporate
         of another within the meaning of section 50 of the Corporations Law
         (Queensland).

         "SPECIFICATIONS" means the specifications for Natural Gas prescribed
         from time to time under the Regulations of the Gas Act. The
         specifications applying as at the date of this Agreement are those set
         out in Schedule 2;

         "STANDARD CONDITIONS" means a temperature of fifteen (15) degrees
         Celsius and an absolute pressure of 101.325 kPa;

         "TAKE OR PAY QUANTITY" means the Minimum Monthly Quantity adjusted by
         deducting all amounts of Contract Gas equal to any amount, up to the
         MDQ for each Day, that the Sellers have failed to make available to
         Buyer for nomination (whether due to Force Majeure events or not) or
         has failed to deliver to the Buyer in accordance with the Daily
         Nomination, that the Buyer is obliged to pay for in a Month whether or
         not it has nominated such quantity for delivery;

         "TERM" means the period of time during which this Agreement is in force
         pursuant to clause 12;

         "TJ" means one terajoule (1,000 GJ); and

         "TERMINATION DATE" means either the date five (5) years after the
         Commencement Date, or the date to which the term is extended pursuant
         to clause 12.3 or the date on which this Agreement is terminated
         pursuant to clause 6.2.4, 11, 13, 16.3 or 25, whichever is appropriate.

1.2      GENERAL

         In this Agreement, unless the context otherwise requires:

         1.2.1    a reference to any law, legislation or legislative provision
                  includes any statutory modification or re-enactment of, or
                  legislative provision substituted for, and any statutory
                  instruments issued under that legislation or legislative
                  provision;

         1.2.2    the singular includes the plural and vice versa;

                                       7
<PAGE>   8

         1.2.3    a reference to an individual or person includes a corporation,
                  partnership, joint venture, association, authority, trust,
                  state or government and vice versa;

         1.2.4    a reference to any gender includes all genders;

         1.2.5    a reference to a recital, clause, schedule, appendix, annexure
                  or exhibit is to a recital, clause, schedule, appendix,
                  annexure or exhibit of or to this Agreement;

         1.2.6    a recital, schedule, appendix, exhibit, annexure or a
                  description of the parties referred to in this Agreement forms
                  part of this Agreement;

         1.2.7    a reference to any agreement or document is to that agreement
                  or document (and, where applicable, any of its provisions) as
                  amended, novated, supplemented or replaced from time to time;

         1.2.8    a reference to any party to this Agreement or any other
                  document or arrangement includes that party's executors,
                  administrators, substitutes, successors and permitted assigns;

         1.2.9    where an expression is defined, another part of speech or
                  grammatical form of that expression has a corresponding
                  meaning;

         1.2.10   a reference to "DOLLARS" or "$" is to Australian currency;

         1.2.11   a reference to bankruptcy or winding up includes bankruptcy,
                  winding up, liquidation, dissolution, becoming an insolvent
                  under administration (as defined in section 9 of the
                  Corporations Law), the appointment of an administrator and the
                  occurrence of anything analogous or having a substantially
                  similar effect to any of those conditions or matters under the
                  law of any applicable jurisdiction, and to the procedures,
                  circumstances and events which constitute any of those
                  conditions or matters;

         1.2.12   a reference to a matter being "TO THE KNOWLEDGE" of a person
                  means that the matter is to the best of the knowledge and
                  belief of that person after making reasonable enquiries in the
                  circumstances;

         1.2.13   a reference to a matter being written includes that matter
                  being in any mode of representing or reproducing words,
                  figures or symbols in written form; and

         1.2.14   all references to units of measurement, in this Agreement, are
                  references to the units of measurement defined in or for the
                  purposes of the National Measurement Act, 1960 (Commonwealth);

         1.2.15   gas measured for the purposes of this Agreement is to be
                  measured by reference to its Gross Heating Value and volume;
                  and

         1.2.16   a reference in this Agreement to a time or date is a reference
                  to the time or date in Brisbane, Australia.

                                       8
<PAGE>   9

1.3      HEADINGS

         In this Agreement, headings are for convenience of reference only and
         do not affect interpretation.

1.4      BUSINESS DAY

         If the day on which any act, matter or thing is to be done under this
         Agreement is not a Business Day, that act, matter or thing:

         1.4.1    if it involves a payment other than a payment which is due on
                  demand, must be done on the preceding Business Day; and

         1.4.2    in all other cases, may be done on the next Business Day.

2        RELATIONSHIP OF THE PARTIES

2.1      SEPARATE AGREEMENT WITH THE SELLERS

         This Agreement shall be construed as a separate agreement between the
         Buyer and each Seller for the sale of that Seller's Ownership
         Percentage of the Contract Gas to be delivered to the Buyer.

2.2      SEVERAL LIABILITY

         The obligations and liability of each Seller under this Agreement are
         several and not joint nor joint and several.

2.3      PARTIES NOT RELEASED

         No Seller shall be responsible for the obligations of any other Seller
         under this Agreement. Default by a Seller under its separate agreement
         with the Buyer shall not release:

         (a)      any other Seller from any of its obligations to the Buyer, or

         (b)      the Buyer from any of its obligations to any other Seller.

2.4      COMMON STREAM

         Contract Gas delivered by the Sellers under this Agreement, may be
         tested, measured and delivered in a common stream, and each Seller
         shall be deemed to have delivered its Ownership Percentage of all
         Contract Gas delivered to the Buyer in accordance with this Agreement.

3.       TITLE TO CONTRACT GAS

         The Sellers shall have title to and be in control and possession of and
         shall assume all risk for the Contract Gas until it is delivered to
         Buyer at the Delivery Point when Buyer

                                       9
<PAGE>   10

         shall take title to and be in control and possession of and shall
         assume all risk for the Contract Gas so delivered.

4.       DELIVERY

4.1      All Contract Gas to be delivered by the Sellers to the Buyer shall be
         delivered at the Delivery Point, where, the ownership of the Contract
         Gas will be transferred from the Sellers to Buyer.

4.2      The Sellers shall deliver Contract Gas to the Delivery Point at a
         pressure which meets the entry specifications of the Duke Queensland
         Gas Pipeline at the Delivery Point.

4.3      The Sellers shall use all reasonable endeavours to ensure that Contract
         Gas is delivered at uniform hourly rates during each Day.

5.       SPECIFICATIONS

5.1      If any Contract Gas delivered or likely to be tendered for delivery is
         Off-Specification Gas:

         5.1.1    the Sellers, as soon as practicable after becoming aware of
                  such non-conformity, shall notify Buyer of the non-conformity
                  and of its cause and probable duration, and shall take such
                  steps as are practicable to bring all Contract Gas tendered
                  thereafter for delivery into conformity with the
                  Specifications; and

         5.1.2    If Off-Specification Gas has been tendered for delivery but
                  not delivered, Buyer, being aware that the Contract Gas so
                  tendered is Off-Specification Gas, may:

                  5.1.2.1  refuse to accept all or part of such
                           Off-Specification Gas until the non-conformity has
                           been remedied;

                  5.1.2.2  take delivery of all or part of the Off-Specification
                           Gas in which case it shall be deemed to be Contract
                           Gas and shall be paid for at the Contract Price.

6.       QUANTITY AND PROCEDURES FOR THE SUPPLY OF CONTRACT GAS

6.1      CONTRACT QUANTITIES

         Subject to clause 5, the Sellers shall sell and deliver to Buyer and
         Buyer shall purchase and take delivery from Seller of Contract Gas
         including deliveries of Make up Gas previously paid for and to be
         debited to Buyer's Make up Gas account, on the following conditions:

         6.1.1    subject to clauses 6.2 and 6.3, the Maximum Daily Quantity
                  shall be as set out in Schedule 6;

                                       10
<PAGE>   11

         6.1.2    the Sellers must use their reasonable endeavours, on each and
                  every Day, to make available for delivery to the Buyer , the
                  amount of Contract Gas nominated by the Buyer, provided that
                  no Seller shall be obliged to make available for delivery any
                  quantity of Gas in excess of its Ownership Percentage of the
                  amount of Contract Gas nominated by Buyer;

         6.1.3    on any Day Buyer has the right to nominate, at its sole
                  discretion, an amount of Contract Gas up to the Maximum Daily
                  Quantity;

         6.1.4    notwithstanding clause 6.1.3, in any Month, Buyer's minimum
                  obligation to take or pay for Contract Gas, in that Month,
                  shall be the Take or Pay Quantity and Buyer shall pay for such
                  amount whether taken or not.

6.2      REDUCTION OF MDQ BY BUYER

         6.2.1    Despite any other provisions of this Agreement and in addition
                  to any other right or remedy that Buyer may have under this
                  Agreement or otherwise, if during any Reconciliation Period
                  Sellers fail to deliver an amount of Contract Gas equal to or
                  greater than the aggregate of fifty (50) percent of the
                  Maximum Daily Quantity for each Day multiplied by the number
                  of Days in that Reconciliation Period, Buyer may, at its sole
                  discretion, reduce the Maximum Daily Quantity by giving one
                  (1) Month written notification of the reduction. Such notice
                  must be given within one (1) Month of the end of the
                  Reconciliation Period.

         6.2.2    The reduced Maximum Daily Quantity shall be not less than the
                  quantity calculated as follows;

                  Reduced Maximum Daily Quantity  =  M D Q * Reduction Factor

                  where

                  Reduction Factor = A / (0.5 * MDQ * B)

                  and

                  A = the aggregate quantity of Contract Gas made available for
                  delivery at the Delivery Point during the Reconciliation
                  Period.

                  B = the number of Days in the Reconciliation Period.

                  * = multiplied by.

                  / = divided by.

         6.2.3    Despite any other provisions of this Agreement and in addition
                  to any other right or remedy that Buyer may have under this
                  Agreement or otherwise, if, during any Reconciliation Period,
                  Sellers fail to deliver, an amount of Contract Gas equal to or
                  greater than forty (40) percent of the Maximum Daily Quantity,
                  adjusted for any quantities of Contract Gas not delivered
                  because of an event of

                                       11
<PAGE>   12

                  Force Majeure, for more than eighteen (18) Days of that
                  Reconciliation Period, Buyer may, at its sole discretion,
                  reduce the Maximum Daily Quantity by giving one (1) Month
                  written notification of the reduction. Such notice must be
                  given within one (1) Month of the last of the eighteen (18)
                  Days.

                  The reduced Maximum Daily Quantity shall be not less than
                  eighty (80) percent of the Maximum Daily Quantity applying
                  during that Reconciliation Period.

         6.2.4    Despite any other provision of this Agreement and in addition
                  to any other right or remedy that the Buyer may have under
                  this Agreement or otherwise, if, during any period of one
                  calendar month, the Sellers fail to deliver an amount of
                  Contract Gas equal to or greater than forty (40) percent of
                  the Maximum Daily Quantity, adjusted for any quantity of
                  Contract Gas not delivered because of an event of Force
                  Majeure, for more than fourteen (14) Days, the Buyer may, at
                  its sole discretion, terminate this Agreement by giving seven
                  (7) Days notice in writing to the Sellers

         6.2.5    Pursuant to clauses 6.2.1, 6.2.2 and 6.2.3 the reduced amount,
                  being the Maximum Daily Quantity for the balance of the Term,
                  will take effect immediately upon receipt of such notification
                  by the Sellers and is subject to further reduction at the end
                  of each Reconciliation Period pursuant to this Agreement.

6.3      REDUCTION OF MDQ BY SELLERS

         6.3.1    Despite any other provisions of this Agreement and in addition
                  to any other right or remedy that Sellers may have under this
                  Agreement or otherwise, if during any Reconciliation Period
                  Buyer fails to take or pay for an amount of Contract Gas equal
                  to or greater than the aggregate of seventy (70) percent of
                  the Maximum Daily Quantity for each Day multiplied by the
                  number of Days in that Reconciliation Period, adjusted by
                  deducting all amounts of Contract Gas equal to any amount up
                  to the Maximum Daily Quantity that the Sellers have failed to
                  deliver to the Buyer in accordance with the Daily Nomination,
                  Sellers may, at their sole discretion, reduce the Maximum
                  Daily Quantity by giving one (1) Month written notification of
                  the reduction. Such notice must be given within one (1) Month
                  of the end of the Reconciliation Period.

         6.3.2    The reduced Maximum Daily Quantity shall be not less than the
                  quantity calculated as follows;

                  Reduced Maximum Daily Quantity  =  M D Q * Reduction Factor

                  where

                  Reduction Factor = A / (0.7 * MDQ * B)

                  and

                  A = the aggregate quantity of Contract Gas actually taken or
                  paid for without being taken during the Reconciliation Period

                                       12
<PAGE>   13

                  B = the number of Days in the Reconciliation Period.

                  *     =  multiplied by.

                  /     =  divided by.

         6.3.3    Despite any other provisions of this Agreement and in addition
                  to any other right or remedy that Sellers may have under this
                  Agreement or otherwise, if during any Reconciliation Period,
                  Buyer fails to take or pay for without taking, an amount of
                  Contract Gas equal to or greater than forty (40) percent of
                  the Maximum Daily Quantity, adjusted by deducting all amounts
                  of Contract Gas equal to any amount up to forty (40) percent
                  of the Maximum Daily Quantity, that the Sellers have failed to
                  deliver, for more than eighteen (18) Days of that
                  Reconciliation Period, Sellers may, at their sole discretion,
                  reduce the Maximum Daily Quantity by giving one (1) Month
                  written notification of the reduction. Such notice must be
                  given within one (1) Month of the last of the eighteen (18)
                  Days.

                  The reduced Maximum Daily Quantity shall be not less than
                  eighty (80) percent of the Maximum Daily Quantity applying
                  during that Reconciliation Period.

         6.3.4    Pursuant to clauses 6.3.1, 6.3.2 and 6.3.3 the reduced amount,
                  being the Maximum Daily Quantity for the balance of the Term,
                  will take effect immediately upon receipt of such notification
                  by the Buyer and is subject to further reduction at the end of
                  each Reconciliation Period pursuant to this Agreement.

6.4      NOMINATIONS

         Subject to clause 6.1, the Daily and Monthly scheduling procedures for
         the delivery and receipt of Contract Gas shall be as follows:

         6.4.1    not later than five (5) Business Days before the end of the
                  Month prior to each Month of delivery, Buyer shall notify the
                  Sellers in writing of Buyer's estimates of the quantities of
                  Contract Gas which Buyer wishes to take on each Day of the
                  Month of delivery for that Month;

         6.4.2    not later than forty eight (48) hours after receipt of such
                  nomination, Sellers shall notify Buyer in writing of the
                  actual amount of Contract Gas to be delivered on each Day of
                  that Month;

         6.4.3    subject to clause 6.4.4, the quantity so nominated for each
                  Day pursuant to clause 6.4.1 shall form the Daily Nomination
                  for that Day of the Month of delivery in question;

         6.4.4    if Buyer wishes to change its Daily Nomination given pursuant
                  to clause 6.4.1, for any Day in the applicable Month, then it
                  may do so, and if it so chooses it must do so by notice given
                  to the Sellers before midday on the Day, one (1) Day before
                  the Day in question and the quantity then so nominated shall
                  be the Daily Nomination for that Day.

                                       13
<PAGE>   14

6.5      MAKE UP GAS

         6.5.1    In any Month, after Buyer has purchased and taken delivery of
                  a quantity of Contract Gas equal to the Take or Pay Quantity ,
                  any further deliveries of Contract Gas during that Month shall
                  be deemed to be delivery of Make up Gas accumulated in respect
                  of prior Months to the extent that any such Make up Gas has
                  been accumulated, and if the aggregate of the quantities of
                  the further deliveries of Contract Gas are in excess of the
                  quantity of Make up Gas available, then Buyer shall pay for
                  any excess in accordance with Schedule 1.

         6.5.2    Buyer shall be entitled to take delivery of Make up Gas for a
                  period of twelve (12) months following the Termination Date.

                  All the terms and conditions of this Agreement, except clauses
                  9 and 10 shall apply in respect of such deliveries. Buyer
                  shall cease to have any rights to Make Up Gas not delivered by
                  the end of the period referred to in this clause 6.5.2.

         6.5.3    Deliveries of Make up Gas shall be at no additional charge to
                  Buyer.

6.6      FIELD FAILURE EVENT

         6.6.1    The Sellers acknowledge that, as the volumes of Gas (as shown
                  in Schedule 6) supplied under this Agreement increase, any
                  interruption to supply, except as permitted under Clause 11,
                  increases the difficulty for the Buyer to satisfy the Buyer's
                  obligations under its on-supply agreements.

         6.6.2    The Sellers will work together with the Buyer in good faith to
                  agree on measures to be implemented prior to the Delivery
                  Point to reduce the impact of variations of field gas output
                  and of failure of components of the field production,
                  collection and compression system.

         6.6.3    Without limiting clause 6.6.2, the Parties agree that the
                  following measures shall be undertaken by the Sellers to
                  achieve the above objectives:

                  6.6.3.1  Separation of, and if necessary, duplication of parts
                           of the gas gathering and collection system so that
                           failure of a single pipe system does not lead to loss
                           of entire Gas available for delivery;

                  6.6.3.2  Arrangement of the compressor station and the entry
                           of the gas collection system into the compressor
                           station to ensure that a single compressor failure
                           does not result in loss of ability to compress at
                           least 50% of the Gas supplied under this Agreement;

                  6.6.3.3  Maintenance, on site, of essential spare parts and
                           appropriately skilled personnel to address
                           contingency failures and repairs.

         6.6.4    The Buyer acknowledges that these measures will require the
                  Sellers to work with the Field Operator (where the Field
                  Operator is not one of the Sellers). The Sellers agree to use
                  best endeavours to ensure that any measures agreed between the
                  Parties are implemented by the Field Operator.

                                       14
<PAGE>   15

7.       DEDICATION OF RESERVES AND COMMITMENT TO DRILL

7.1      Subject to the terms and conditions of this Agreement, Sellers hereby
         agree to sell and deliver to Buyer at the Delivery Point all Contract
         Gas, up to the Maximum Daily Quantity, produced or saved from wells now
         or hereafter drilled within the Contract Area as described in Schedule
         4.

7.2      The Parties agree that Gas which is available from the Contract Area
         shall first be used to satisfy the Contract Gas requirements under the
         First Agreement. Any Seller under this Agreement which is not a party
         to the First Agreement, shall commit to satisfy the delivery
         requirements of this Agreement with priority over any other gas sales
         from the property attributable to that Seller's interest.

7.3      The Sellers will not offer to supply quantities of Gas which may become
         available from the Contract Area to persons other than the Buyer and
         purchasers who have in place gas sale and purchase agreements in
         existence at the date of this Agreement, without first satisfying the
         Contract Gas requirements under the First Agreement and this Agreement.

7.4      Sellers agree that they shall use their reasonable endeavours to ensure
         that a minimum of twenty (20) wells shall be drilled within the
         Contract Area during the first two (2) years of this Agreement.

7.5      Provided the Sellers shall have complied with their obligations under
         this Agreement, the rights or entitlements of the Buyer in the event of
         any failure by the Sellers to make available for delivery the amount of
         Contract Gas nominated by the Buyer shall be limited to those set out
         in this Agreement.

8.       MEASUREMENT OF VOLUMES AND REGULATION OF PRESSURES

8.1      The Sellers shall be responsible for installing, operating and
         maintaining the devices for measuring the Contract Gas or for arranging
         for the same to be done. The quantities of Contract Gas delivered by
         the Sellers will be measured and recorded by such measuring and
         recording devices, located immediately prior to the Delivery Point.

8.2      Any Party may, at its own risk and expense, install check measuring and
         recording devices, providing they do not interfere or influence the
         operation of the devices installed pursuant to clause 8.1 and providing
         that Party negotiates its own terms with the owner of the Duke
         Queensland Gas Pipeline.

8.3      Each Party or its agent shall, subject to it obtaining agreement from
         the owner of the Duke Queensland Gas Pipeline, have the right to be
         present to observe installation, reading, cleaning, changing,
         repairing, inspecting, calibrating or adjusting of the measuring and
         recording devices referred to in clause 8.1.

8.4      The Parties agree that the provisions of Schedule 3 will govern the
         measurement of Contract Gas for the purposes of this Agreement. If a
         Party is required to take action

                                       15

<PAGE>   16

         under an agreement which it has with another party to ensure that the
         requirements of Schedule 3 are met, that Party shall take all such
         action and do all such things as may be required to achieve that
         result.

9.       CONTRACT PRICE

9.1      The Contract Price at the Delivery Point, expressed in dollars per GJ,
         shall be calculated as in Schedule 1.

9.2      The Sellers shall be liable for all current and future taxes, imposts,
         royalties and liability incurred or levied, by or to the Federal
         Government or the Government of the State of Queensland, at or prior to
         the Delivery Point and Buyer shall be responsible for all current and
         future taxes, imposts and liability incurred or levied, by or to the
         Federal Government or the Government of the State of Queensland, after
         the Delivery Point. The Contract Price is inclusive of all such
         royalties, taxes and other sums as at the effective date of this
         Agreement.

9.3      GST

9.3.1    In this clause 9.3.1, the following definitions apply:

         9.3.1.1  GST means the goods and services tax as imposed by the GST Law
                  together with any related interest, penalties, fines or other
                  charge only to the extent they arise from the Buyer's failure
                  to pay when due.

         9.3.1.2  GST AMOUNT means any Payment (or the relevant part of that
                  Payment) multiplied by the appropriate rate of GST (currently
                  10%).

         9.3.1.3  GST LAW has the meaning given to that term in A New Tax System
                  (Goods and Services Tax) Act 1999, or, if that Act does not
                  exist for any reason, means any Act imposing or relating to
                  the imposition or administration of a goods and services tax
                  in Australia and any regulation made under that Act.

         9.3.1.4  INPUT TAX CREDIT has the meaning given to that term by the GST
                  Law.

         9.3.1.5  PAYMENT means any amount payable under or in connection with
                  this agreement including any amount payable by way of
                  indemnity, reimbursement or otherwise and includes the
                  provision of any non-monetary consideration.

         9.3.1.6  TAX INVOICE has the meaning given to that term by the GST Law.

         9.3.1.7  TAXABLE SUPPLY has the meaning given to that term by the GST
                  Law.

9.3.2    The parties agree that:

         9.3.2.1  all Payments have been calculated without regard to GST;

                                       16
<PAGE>   17

         9.3.2.2  each party will comply with its obligations under the Trade
                  Practices Act 1974 when calculating the amount of any Payment
                  and the amount of any relevant Payments will be adjusted
                  accordingly;

         9.3.2.3  if the whole or any part of any Payment is the consideration
                  for a Taxable Supply, the Buyer must pay to the Seller an
                  additional amount equal to the GST Amount, either concurrently
                  with that Payment or as otherwise agreed in writing;

         9.3.2.4  any reference to a cost or expense in this Agreement excludes
                  any amount in respect of GST forming part of the relevant cost
                  or expense when incurred by the relevant party for which that
                  party can claim an Input Tax Credit; and

         9.3.2.5  The payee will provide to the payer a Tax Invoice at the same
                  time as any GST Amount is payable

10.      BILLING AND METHOD OF PAYMENT

10.1     MONTHLY STATEMENT

         On or before the 10th day of each Month, the Sellers shall furnish to
         the Buyer a reconciliation and measurement statement in respect of the
         previous Month, or such part of that Month during which Contract Gas
         was made available by the Sellers, showing:

         (a)  the quantity of Contract Gas delivered;

         (b)  the quantity of Make up Gas delivered (if any);

         (c)  the price and total amount payable to each of the Sellers in
              respect of the Contract Gas delivered, together with any
              calculations necessary to establish the price and total amount to
              be paid; and

         (d)  the amount of any payment due each of the Sellers in respect of
              the Take or Pay Quantity not taken.

10.2     RECONCILIATION PERIOD STATEMENT

         On or before the tenth (10) Day of the Month following the expiry of
         each Reconciliation Period, the Sellers and the Buyer shall each
         furnish to the other Party a Reconciliation Period Statement showing
         for the previous Reconciliation Period all information necessary for
         either Party to exercise their rights under clauses 6.2, 6.3 and 10.4.

10.3     PAYMENT

         On or before the last Business Day of each Month, or within fourteen
         (14) Business Days after receipt of the monthly statement, whichever is
         the later, the Buyer shall pay to the Sellers the amount specified in
         the monthly statement. Any amounts due under this Agreement owed by
         Sellers to Buyer may be offset against any amounts invoiced by Sellers
         to Buyer.

                                       17

<PAGE>   18

         If any amount remains owing by the Sellers to the Buyer after such
         offset, Buyer shall issue an invoice to the Sellers by the tenth (10th)
         Day of the Month following the relevant Month and Sellers shall pay the
         invoice within fourteen (14) Business Days of receipt of invoice or by
         the last Day of the Month, whichever is the later.

         Unless otherwise agreed, all payments to be made pursuant to this
         Agreement shall be made by bank deposit to a bank account in Australia
         nominated in writing by the Sellers and the Buyer by no later than the
         due date for payment.

10.4     REBATE BY SELLERS TO BUYER

         Despite any other provision of this Agreement and in addition to any
         other remedy that Buyer may have under this Agreement or otherwise, if
         during any Reconciliation Period, Sellers fail to make available for
         delivery to the Buyer, an amount of Contract Gas equal to or greater
         than the aggregate quantity of fifty (50) percent of the Maximum Daily
         Quantity for each Day multiplied by the number of Days in that
         Reconciliation Period, Sellers shall rebate to the Buyer an amount
         equal to the quantity of Contract Gas taken or paid for but not taken
         during that Reconciliation Period multiplied by five (5) percent of the
         Contract Price.

10.5     INTEREST

         Payments made after the fourteenth Business Day following receipt of
         monthly statement will incur interest at the Interest Rate, with
         interest calculated from the twenty first Business Day following
         receipt of monthly statement or the twenty first Day of the Month
         following the relevant Month, whichever is the later.

10.6     DISPUTED STATEMENT

         In the event of a bona fide dispute in respect of any payment of any
         statement furnished by either Party under this clause, the Party that
         has an objection in regard to any portion of the amount of the invoice
         shall:

        (a) notify the other Party of the nature of the dispute and the amount
            in dispute;

        (b) make payment of any amount not in dispute in accordance with clause
            10.3.

        The Parties shall, upon request, each furnish to the other copies of all
        records relevant to the dispute. Any disputed amount which is
        subsequently found to be payable by or repayable shall be due and
        payable no later than 14 Days after resolution of the dispute together
        with interest on that amount calculated at the Interest Rate from the
        due date for payment.

11.     FORCE MAJEURE

11.1    DEFINITION

        11.1.1       For purposes of this Agreement, Force Majeure means any
                     event or circumstance not within the control of a Party and
                     which by the exercise of due diligence, that Party is not
                     reasonably able to prevent or overcome,

                                       18

<PAGE>   19

                    including without limiting the generality of the nature of
                    those events or circumstances:

                    (a)  acts of God, including without limitation, earthquakes,
                         floods, wash outs, landslides, lightning, storms and
                         the elements;

                    (b)  strikes, lockouts, bans, slowdowns or other industrial
                         disturbances except those that are directed exclusively
                         at the party seeking to rely on Force Majeure;

                    (c)  acts of enemy, wars, blockades or insurrections, riots
                         and civil disturbances, arrest and restraint of rulers
                         and peoples;

                    (d)  fire or explosion;

                    (e)  native title claims;

                    (f)  epidemic or quarantine;

                    (g)  order of any court or tribunal or the order, act, or
                         omission or failure to act of any government or
                         governmental authority having jurisdiction;

                    (h)  equipment breakdown, accident, breakages or accident to
                         machinery or pipelines, the necessity for making
                         repairs and/or alterations in machinery or pipelines
                         including machinery or pipelines of a third party
                         supplier to the Party seeking to rely on Force Majeure;
                         or

                    (i)  any other event which is not within the reasonable
                         control of the Party.

          11.1.2  It is acknowledged that the following matters will not
                  constitute Force Majeure under this Agreement:

                  11.1.2.1    lack of finances;

                  11.1.2.2    lack of funds;

                  11.1.2.3    inability to borrow funds;

                  11.1.2.4    Buyer's inability to economically use Contract Gas
                              purchased under this Agreement;  or

                  11.1.2.5    Sellers' inability to acquire Contract Gas
                              supplies on an economically viable basis.

11.2      CONSEQUENCES OF FORCE MAJEURE

          Subject to clause 11.3, non-performance as a result of Force Majeure
          by either Party of any obligation or condition required by this
          Agreement to be performed, other than the payment for Contract Gas
          already delivered and the payment of any debt or liability already
          incurred:

                                       19
<PAGE>   20

          11.2.1   shall be excused during the time and to the extent that such
                   performance by that Party is prevented, wholly or in part, by
                   Force Majeure; and

          11.2.2   shall not to that extent give rise to any liability to the
                   other Party for any direct, indirect, consequential or
                   special losses or damages of any kind arising out of, or in
                   any way connected with that non-performance.

11.3       NOTIFICATION AND DILIGENCE

           A Party which is, by reason of Force Majeure, unable to perform any
           obligation or condition required by this Agreement to be performed
           shall:

           11.3.1   notify the other Party as soon as possible giving:

                    11.3.1.1   reasonably full particulars of the event or
                               circumstance of Force Majeure;

                    11.3.1.2   the date of commencement of the event or
                               circumstance and an estimate of the period of
                               time required to enable it to resume full
                               performance of its obligations; and

                    11.3.1.3   where possible, the means proposed to be adopted
                               to remedy or abate the Force Majeure.

           11.3.2   use all reasonable diligence and employ all reasonable means
                    to remedy or abate the Force Majeure as expeditiously as
                    possible, but nothing in this clause 11 shall require a
                    Party to settle a strike, lockout, ban, slowdown or other
                    industrial disturbance, civil disobedience or native title
                    claim against its judgment, and it is acknowledged that
                    settlement of any such disturbance shall be entirely within
                    the discretion of the Party affected;

           11.3.3   resume performance as expeditiously as possible after
                    termination of the Force Majeure or after the Force Majeure
                    has abated to an extent which permits resumption of
                    performance;

           11.3.4   notify the other Party when the Force Majeure has terminated
                    or abated to an extent which permits resumption of
                    performance to occur; and

           11.3.5   provide the other Party with as much notice as is
                    practicable of the time and date when resumption of
                    performance will occur.

11.4       LIABILITY NOT RELIEVED

           Events of Force Majeure or circumstances affecting the performance
           under this Agreement by either the Sellers or Buyer, however, shall
           not relieve that Party of liability in the event, and to the extent
           that, its negligence caused or contributed to its failure to perform
           under this Agreement or in the event of its failure to use all
           reasonable endeavours to remedy the situation and to remove the event
           or circumstances giving rise to the Force Majeure in an adequate
           manner with all reasonable dispatch.

                                       20
<PAGE>   21

11.5     PROLONGED FORCE MAJEURE

         If a Party has invoked the provisions of this clause 11 and the same
         event of Force Majeure prevents or inhibits the performance of any
         obligation or condition required to be performed under this Agreement
         for a period of four (4) Months, then the Sellers and the Buyer shall
         consult in good faith to decide what action should be taken to carry
         out the intentions of this Agreement. If after a further one (1) Month
         the Parties are unable to agree that the Force Majeure can reasonably
         be resolved, then the Party not claiming to be prevented from
         performance by Force Majeure may terminate this Agreement upon the
         expiry of thirty (30) Days written notice to the other Party.

12.      TERM OF AGREEMENT

12.1     The effective date of this Agreement shall be the date of this
         Agreement.

12.2     This Agreement will remain in effect until the Termination Date.

12.3     Not more than four (4) years after the Commencement Date, Buyer will
         enter into discussions with the Sellers for an extension of supply
         period for up to five (5) years regarding pricing and supply terms.

13.      DEFAULT

13.1     If a Party defaults in performing its obligations under this Agreement,
         the non-defaulting Party may give the defaulting Party notice in
         writing specifying the default. Upon receipt of the notice, the
         defaulting Party shall have fifteen (15) Business Days or, in the event
         of a default to pay moneys due, seven (7) Business Days from the date
         of receipt of the default notice to rectify the default. If the default
         has not been rectified in such period the non-defaulting Party may
         suspend its obligations under this Agreement until the default is
         rectified or terminate this Agreement.

14.        ASSIGNMENT

14.1       ASSIGNMENT BY BUYER

           14.1.1   Buyer may only assign its rights and obligations under
                    this Agreement to any third party where:

                    (a)  in the reasonable opinion of the Sellers the assignee
                         is financially and technically capable of complying
                         with the obligations of the Buyer hereunder; and

                    (b)  the assignee first covenants in writing with the
                         Sellers to assume and be bound by the obligations of
                         the Buyer hereunder.

           14.1.2   Notwithstanding clause 14.1.1 Buyer may Dispose of the
                    whole or any part of its rights and obligations under
                    this Agreement to any Related Corporation. Such right of
                    assignment may only be exercised subject to prior
                    written notice to the Sellers.

                                       21
<PAGE>   22

14.2     ASSIGNMENT BY THE SELLERS

         Any Seller may assign to any third party its rights and obligations
         under this agreement or any part thereof provided that:

         (a)  in the reasonable opinion of the Buyer the assignee is
              financially and technically capable of complying with the
              obligations of the assignor hereunder; and

         (b)  the assignee first covenants in writing with the Buyer to assume
              and be bound by the obligations of the assignor hereunder.

15.      WARRANTIES

15.1.    The Sellers represent, warrant and guarantee to Buyer that:

         15.1.1. they have full corporate power and authority to enter into
                 this Agreement;

         15.1.2. their Ownership Percentage of the Contract Gas to be delivered
                 under this Agreement will, when delivered at the Delivery
                 Point, be free from liens, charges, encumbrances and adverse
                 claims which might prevent, impede or prejudice their rights to
                 sell and dispose of the Contract Gas, other than their existing
                 First Agreement with Allgas Energy Ltd.;

         15.1.3. to the knowledge of the Sellers, they have the capacity, during
                 each Contract Year, to deliver to Buyer, not less than the
                 Maximum Daily Quantity of Contract Gas in accordance with the
                 provisions of this Agreement; and

         15.1.4. they have adequate agreements to ensure their ability to
                 transport and deliver sufficient Contract Gas to the Delivery
                 Point for the Term.

15.2.    Buyer represents, warrants and guarantees to the Sellers that:

         15.2.1. it has adequate agreements to ensure its ability to transport
                 the Contract Gas from the Delivery Point for the Term; and

         15.2.2. it has full corporate power and authority to enter
                 into this Agreement.

16.      CONDITIONS PRECEDENT

16.1.    This Agreement shall not come into force until the satisfaction of the
         following conditions or their waiver at any time by the Buyer:

         16.1.1. the execution and coming into force of such gas transportation
                 agreements for a term at least equal to the Term of this
                 Agreement to effect transportation of the Contract Gas;

         16.1.2. the approval of the Board of the Buyer;

                                       22

<PAGE>   23

        16.1.3. the provision of information by the Sellers to the Buyer
                establishing to the Buyer's satisfaction that the Sellers (or
                their agent) have obtained a funding commitment and all
                regulatory approvals necessary to undertake a 20 well
                exploration programme on ATP526P to establish sufficient
                production as contemplated by this Agreement..

16.2.  As soon as practicable after the execution of this Agreement, Buyer will
       use reasonable endeavours to achieve the satisfaction of the conditions
       referred to in clause 16.1 and will advise the Sellers immediately upon
       satisfaction of any of the conditions.

16.3.  In the event that Buyer has not notified the Sellers that the conditions
       referred to in clause 16.1 are not either satisfied or waived within
       thirty Days of the signing of this Agreement, then either Party may
       terminate this Agreement by notice in writing.

17.    DAMAGES

       Notwithstanding what is contained in this Agreement, expressly or by
       implication, except in the event of a breach of the representation,
       warranties and guarantee in clause 15, neither the Sellers nor Buyer
       shall have any liability to the other whatsoever for loss of business or
       loss of profits, howsoever caused, arising out of or in connection with
       this Agreement.

18.    AUDITING

       Each Party has the right upon reasonable notice, at its sole expense and
       during normal working hours, to examine such of the records of the other
       Party as necessary to verify the accuracy of any invoice, statement,
       charge, notice or computation made pursuant to the stipulations of this
       Agreement. If any such examination reveals an inaccuracy in the invoice,
       the necessary adjustments in such invoice and the corresponding payments
       will be promptly made, provided that no adjustment will be made for any
       invoice or payment made after the lapse of one (1) year from the
       rendition thereof, and provided that this stipulation of the Contract
       survives any expiry or termination of this Contract for a period of one
       (1) year from the date of such expiry or termination for such invoice and
       payment adjustments.

19.    CONFIDENTIALITY

       The terms of this Agreement and all data and information relating to the
       sale and purchase of Gas pursuant to this Agreement shall be kept
       confidential and shall not be disclosed by a Party to any person without
       the prior written approval of the other Party except where disclosure is
       made by a Party:

       (a)    to its employees, independent contractors, advisers, lawyers and
              auditors for the purposes of this Agreement, and that Party has
              taken all precautions which are reasonably necessary to ensure
              that those persons to whom disclosure may be made under this
              clause shall keep the data and information confidential;

       (b)    as required by a Securities Commission having jurisdiction over
              that Party or over a Related Corporation of that Party, or by the
              rules of any Stock Exchange

                                       23

<PAGE>   24

              on which the shares of a Party, or a Related Corporation of that
              Party may then be listed;

       (c)    to the extent required by law or by the order of a court
              exercising competent jurisdiction to be disclosed by a Party, or
              by the Related Corporation of that Party referred to in
              paragraph (b);

       (d)    to a Related Corporation of the disclosing Party providing the
              disclosing Party assumes responsibility for maintaining the
              confidentiality of the data and information disclosed;

       (e)    to the extent that the data and information is already lawfully
              within the public domain;

       (f)    for the purpose of any litigation or arbitration proceedings which
              may arise from this Agreement;

       (g)    to a bank or other lending agency necessary in connection with the
              funding by a Party;

       (h)    to any employee or Minister of the State of Queensland provided
              that the fact that the information is confidential is communicated
              to that person and that person has agreed to keep that information
              confidential.

       If at any time the disclosing Party requests, the receiving Party must
       return, and procure that any of its Related Corporations return within
       seven days of such request, the confidential information to the
       disclosing Party as the disclosing Party directs. The obligations of the
       Parties under this clause shall be continuing obligations and shall
       continue to bind the Parties for a period of one year after the expiry of
       the term of this Contract.

20.    ENTIRE AGREEMENT

       This Agreement constitutes the entire agreement between the Parties as to
       the terms upon which the sales and purchase of Contract Gas takes place
       and supersedes all prior or contemporaneous understanding, agreement or
       prior warranties, oral or written with the exception of the existing
       First Agreement.

21.    CESSATION OF INDIVIDUAL CLAUSES

       If any clause or part of a clause of this Agreement ceases to be
       enforceable or is terminated by the Parties, such cessation or
       modification to this Agreement shall be binding on each Party unless
       agreed to in writing by both Parties.

22.    LAW AND DISPUTE RESOLUTION

22.1   JURISDICTION

       This Agreement shall be governed by the laws for the time being in force
       in the State of Queensland and, subject to the entirety of this clause
       22, the courts of that State and the courts hearing appeals therefrom
       shall have the exclusive jurisdiction in respect of any disputes arising
       out of or in connection with this Agreement.

                                       24
<PAGE>   25

22.2   DISPUTE RESOLUTION

       The Parties will attempt in good faith to resolve promptly any
       controversy or claim arising out of or relating to this Agreement by
       entering into negotiations in accordance with the following procedure
       before taking any legal proceedings in relation to that controversy or
       claim:

       (a)    the Chief Executive Officer (or a senior manager designated by the
              Chief Executive Officer) of each Party shall meet and attempt to
              resolve the controversy or claim;

       (b)    either Party may given Notice requesting a meeting under
              paragraph (a), which must be convened within seven (7) Days of the
              date of receipt of the Notice;

       (c)    the Parties may retain the non-binding services of an agreed
              mediator in an attempt to resolve the controversy or claim;

       (d)    if the controversy or claim has not been resolved within
              twenty-one (21) Days of the meeting held under paragraph (b),
              either Party may submit the controversy or claim to litigation.

22.3   CONTINUING OBLIGATION

       Neither the commencement nor conduct of mediation or litigation shall
       cause any interruption to the Parties' obligations under this Agreement
       or to the performance by the Parties of their respective obligations
       under this Agreement.

23.    AMENDMENTS

       No person, promise, agreement, warranty or guarantee other than those
       contained in this Agreement and no alteration, amendment or modification
       to this Agreement shall be binding on either Party unless agreed to in
       writing by both Parties.

24.    NOTIFICATION

24.1   GIVING OF NOTICES

       A notice, consent, approval, invoice or other communication under this
       Agreement shall be signed by or on behalf of the Party giving it,
       addressed to the Party to whom it is to be given and:

       24.1.1 delivered to that Party's address;

       24.1.2 sent by pre-paid mail to that Party's address; or

       24.1.3 transmitted by facsimile to that Party's address.

24.2   TIMING OF RECEIPT

       A Notice given to a Party in accordance with this clause 24 shall be
       treated as having been given and received:

                                       25
<PAGE>   26

       24.2.1 if delivered to a Party's address, on the day of delivery if a
              Business Day, otherwise on the next Business Day;

       24.2.2 if sent by pre-paid mail, on the third Business Day after posting,
              or if posting point is not in Australia, on the tenth Business Day
              after posting; and

       24.2.3 if transmitted by facsimile to a Party's address and a correct and
       complete transmission report is received, on the day of transmission if
       transmitted before 5.00 pm on a Business Day, otherwise on the next
       Business Day.

       Any notice required to be given to or by the Sellers shall be treated as
       having been given, if given as representative on behalf of the Sellers,
       to or by Tipperary Oil & Gas (Australia) Pty Ltd, or any other of the
       Sellers which the Sellers may from time to time give notice to Buyer.

24.3      ADDRESSES

       For the purpose of this clause 23 the address of a Party is the address
       set out below or another address of which that Party may from time to
       time give Notice to each other Party:

       (a)      For Buyer:

       Attention:        General Manager - Energy Trading

       Address:          Anzac Square Building
                         200 Adelaide St
                         Brisbane  QLD  4000

       Telephone:        +61-07- 3407 4000
       Facsimile:        +61-7- 3407 5665

       (b)      For Sellers:

       Attention:        President

       Address:          Suite 1550
                         633 Seventeenth Street
                         Denver, Colorado 80202

       Telephone:        +1- 303- 293 9379
       Facsimile:        +1- 303- 292 3428

       Any change of the above which either Party makes must be made known to
       the other Party in writing and as soon as reasonably practicable.

                                       26
<PAGE>   27

25  TERMINATION

25.1.  Either Party may terminate this Agreement by giving notice to the other,
       in the event of:

       25.1.1. the other committing an act of bankruptcy, ceasing to trade or
               going into receivership or liquidation (other than for the
               purposes of amalgamation or reconstruction); or

       25.1.2. the other being materially in breach of any of its obligations
               under this Agreement (other than a failure by the Sellers to
               deliver the nominated amount of Contract Gas) provided that
               notice has been given pursuant to clause 13.

25.2.  The termination of this Agreement, however occurring, shall not affect
       any rights or obligations that may have accrued to either Party prior to
       termination and shall not affect the terms of the Agreement that
       expressly or impliedly continue in force after termination.

                                       27
<PAGE>   28

26.      COUNTERPARTS

         This Agreement may be executed in any number of counterparts and all of
         those counterparts taken together constitute one and the same
         instrument.

Executed as an Agreement:

SIGNED for and on behalf of                               )
                                                          )
TIPPERARY OIL & GAS (AUSTRALIA) PTY. LTD ACN 077 536 871  )
                                                          )
by David L Bradshaw                                       )
                                                          )
the President and Chief Executive Officer                 )
                                                          )
thereof in the presence                                   )

of:  Kenneth L. Ancell

SIGNED for and on behalf of                               )
                                                          )
ENERGEX RETAIL PTY LTD ACN 078 849 055                    )
                                                          )
by J. T. Young                                            )
                                                          )
                                                          )
                                                          )
thereof in the presence                                   )
                                                          )
                                                          )
of:  Anthony Speed                                        )
                                                          )

                                       28
<PAGE>   29

                                   SCHEDULE 1

                                 CONTRACT PRICE

The base Contract Price for Contract Gas shall be [***] as at 1 January 2000
("Base Contract Price").

The "Base Date" shall be 1 January 2000.

The Contract Price for the period from the Commencement Date until 8.00 am on 1
January 2001 will be the base Contract Price and thereafter the Contract Price
will be adjusted at 8.00 am on 1 January in each Contract Year in accordance
with the following formula:

         Contract Price    =  BCP  *  [1 + 0.50 (CPI(n) - CPI(b)/CPI(b)]

where:

           BCP     =   Base Contract Price;

           CPI(n)  =   the CPI for the quarter ended the day before that
                       first day of January in respect of which the Contract
                       Price is being calculated

           CPI(b)  =   the base CPI being the CPI for the quarter ended
                       31 December, 1999.
and
           CPI     =   the Consumer Price Index as published by the
                       Australian Bureau of Statistics for the All Groups
                       Weighted Average of Eight Capital Cities or its
                       successor index in the event that this is modified.

Contract Price units are to be calculated to two (2) decimal places of a cent.
Where the third decimal place is a value of five (5) or greater the second
decimal unit is to be rounded up and where it is less than five (5) it is to be
rounded down.

Should the Consumer Price Index be abolished or abandoned, no longer published,
or its basis for calculation changed in a material respect then the Parties
agree to meet in good faith to agree upon a similar index as a substitute and,
failing agreement, the matter shall be referred to dispute resolution in
accordance with clause 22.3.

*** Text has been omitted and filed separately with the Securities and Exchange
    Commission. Confidential treatment has been requested under 17 C.F.R.
    section 240.24b-2.

                                       29
<PAGE>   30

                                   SCHEDULE 2

                                 SPECIFICATIONS

PART A

THE SPECIFICATIONS PRESCRIBED FROM TIME TO TIME UNDER THE REGULATIONS OF THE GAS
ACT, SUBJECT TO ANY EXEMPTIONS FROM COMPLIANCE GRANTED BY THE CHIEF GAS
EXAMINER. AS AT THE DATE OF THIS AGREEMENT THOSE SPECIFICATIONS ARE AS SET OUT
BELOW:

<TABLE>
<CAPTION>

ITEM
----
<S>                                      <C>
Odours, toxins, hazardous substances,     must be reasonably free from dust, gums, gum forming constituents, other
or solid matter etc                       liquid or solid matter which might cause injury to, or interference with,
                                          proper operation of pipeline regulators, meters, or other appliances
                                          through which it flows or which may interfere with the commercial
                                          utilisation of the Contract Gas by the Buyer

Water content                             must contain not more than 65 milligrams of water vapour per cubic metre

Hydrocarbon dewpoint                      must not exceed a hydrocarbon dew point of 10 degrees Celsius between
                                          the pressures of 1000 kPag and 10000 kPag

Oxygen                                    must not contain more than 0.2 per cent by volume of oxygen

Carbon dioxide                            must not contain more than 3.0 per cent by volume of carbon dioxide

Inerts                                    must not contain more than a combined total of 6.0 per cent by volume
                                          of inert gases

Hydrogen Sulphide                         must not contain more than 7 milligrams per cubic metre of hydrogen
                                          sulphide

Mercaptans                                must not contain more than 15 milligrams per cubic metre of mercaptans

Total Sulphur                             must not contain more than 50 milligrams per cubic metre of total
                                          sulphur

WOBBE Index                               shall have a WOBBE Index not less than 47 and not more than 52

Gross Heating Value                       if the Contract Gas contains more than 4.0 percent by volume of inerts,
                                          then the Contract Gas shall have a Gross Heating Value of not less than
                                          37.9 megajoules per cubic metre of Contract Gas and not more than 42.3
                                          megajoules per cubic metre of Contract Gas on a dry basis and if the
                                          Contract Gas contains less than or equal to 4.0 percent by volume of
                                          inerts, then the Contract Gas shall have a Gross Heating Value of not
                                          less than 35 megajoules per cubic metre of Contract Gas and not more
                                          than 43 megajoules per cubic metre of Contract Gas
</TABLE>

                                       30

<PAGE>   31

PART B
<TABLE>
<S>                                       <C>
Temperature                               Contract Gas must be at a temperature which is not less than zero
                                          (0) degrees Celsius and not higher than the greater of: (i) fifty
                                          (50) degrees Celsius, or (ii) the ambient temperature plus twelve
                                          (12) degrees Celsius but in any event not to exceed sixty (60)
                                          degrees Celsius
</TABLE>

                                       31
<PAGE>   32

                                   SCHEDULE 3

                            METERING METHOD SCHEDULE

The measuring equipment at the Delivery Point shall comply in all respects with
the technical requirements for such equipment as published from time to time by
owner of the Duke Queensland Gas Pipeline, which requirements shall nevertheless
be in accordance with good pipeline industry practice for this type of equipment
and conform to appropriate Australian and internationally recognised standards
and codes.

The latest editions of the following standards in the measurement of gas will be
applied:-

For gas flow measurement using orifice meters:

AGA - 3   "Orifice Metering of Natural Gas"

For gas flow measurement using turbine meters:

AGA - 7  "Measurement of Fuel Gas by Turbine Meters"

For the calculation of gas compressibility:

AGA - 8 "Natural Gas Density and Compressibility" or " AGA Manual for the
Determination of Super-compressibility (NX-19)", as appropriate.

Such standards shall be modified where necessary so as to ensure compliance with
"Australian Standard AS 1000 - 1979 (The International System of Units (SI) and
its Application)"

                                       32
<PAGE>   33

                                   SCHEDULE 4

                                 CONTRACT AREAS

Authority to Prospect 526P, granted 1 November 1992 comprising graticular blocks
shown on Block Identification Map CHAR as 347-348, 419-494, 563-566, 635-638,
707-710, 779-782, 851-854, 923-926, 995-998, 1067-1070, 1139-1142, 1283-1286,
1354-1358, 1426-1430, 1498-1502, 1570-1574 together with all petroleum leases
the subject of current or future application in relation thereto.

                                       33
<PAGE>   34

                                   SCHEDULE 5

                              OWNERSHIP PERCENTAGE

TIPPERARY OIL AND GAS (AUSTRALIA) PTY. LIMITED. having offices at Level 5,359
Queen Street, Brisbane, Queensland 4000.

Ownership of the contract areas:            58.203125%

Ownership of gas to be delivered:           100% *

*   Subject to the rights of the other parties to the Joint Operating Agreement
    dated May 15, 1992, by and between Tri-Star Petroleum Company, as Operator
    and Tipperary Corporation and others, as Non-Operators, including the right
    to participate in sales hereunder upon the terms and conditions of this Gas
    Supply Agreement and upon agreement to comply with the obligation of an
    assignee under clause 14.2 (b) of this Gas Supply Agreement and subject to
    the terms of the First Agreement.

                                       34
<PAGE>   35

                                   SCHEDULE 6

                             MAXIMUM DAILY QUANTITY

<TABLE>
<CAPTION>

                                                               Min MDQ during
                                                               "Field Failure          Total
Date                          Increase in MDQ                      Event"             Max  MDQ
----                          ---------------                  ---------------       ----------

<S>                          <C>                                  <C>                  <C>
Col 1                         Col 2                                Col 3                Col 4

Prior to 31 Dec 2000          Up to [1.5]TJ/d                     [0.75] TJ/d           1.5 TJ/d

Between 1 Jan 2001  &         Up to additional [2] TJ/d           [1.75] TJ/d           3.5 TJ/d
30 Jun 2001

Between 1 Jul 2001 &          Up to additional [2] TJ/d           [2.75] TJ/d           5.5 TJ/d
31 Dec 2001

Between 1 Jan 2002 &          Up to additional [3] TJ/d           [4.25] TJ/d           8.5 TJ/d
30 Jun 2002

From 1 Jul 2002 until         Up to additional                   [5-7.5] TJ/d         10-15 TJ/d
31 May 2005*                  [1.5-6.5] TJ/d
</TABLE>

*The Buyer shall advise the Sellers in writing no later than 1 July 2001 of the
MDQ which is to apply for the period from 1 July 2002 until 31 May 2005. The
Buyer shall be entitled to specify an MDQ of between 10 TJ/d and 15 TJ/d
inclusive for this period. Where the Buyer fails to advise the Sellers of the
MDQ for this period, then an MDQ of 10 TJ/d shall be deemed to apply.

                                       35

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00014-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00014-of-00352.parquet"}]]