Exhibit No. 10.84

[*] indicates that the confidential portion has been omitted from this filed
exhibit and filed separately with the Securities and Exchange Commission.




                              Coal Sales Agreement
                              --------------------
                                Buy Out Agreement
                                -----------------


                                      Among

                              San Juan Coal Company

                      Public Service Company of New Mexico

                          Tucson Electric Power Company




                                Table of Contents
                                -----------------


Section 0 - Parties and Recitals..............................................1

Section 1 - Definitions and Term..............................................1

   1.1      EFFECTIVE DATE....................................................1

   1.2      OUTSTANDING CSA OBLIGATIONS.......................................1

   1.3      SJCC COSTS........................................................1

   1.4      TERM..............................................................2


Section 2 - Conditions Precedent, Representations and Warranties..............2

   2.1      CONDITIONS PRECEDENT..............................................2

   2.2      REPRESENTATIONS AND WARRANTIES....................................2


Section 3 - Coal Reserves Bought Out..........................................2

   3.1      SAN JUAN MINE SURFACE RESERVES....................................2

   3.2      LA PLATA MINE SURFACE RESERVES....................................3


Section 4 - SJCC Compensation.................................................3

   4.1      CSA BUY OUT VALUE.................................................3

   4.2      INFLATION - DEFLATION ADJUSTMENT..................................3

   4.3      PAYMENT OF CBOV...................................................4

   4.4      PAYMENT OF SJCC COSTS.............................................4


Section 5 - CSA Termination...................................................5

   5.1      CSA TERMINATION...................................................5


Section 6 - SJCC Obligations..................................................6

   6.1      SJCC OBLIGATIONS..................................................6


Section 7 - Dispute Resolution................................................6

   7.1      MATTERS TO BE ARBITRATED; NOTICE OF CLAIMS AND DEFENSES;
            PARTY ARBITRATOR DESIGNATION......................................6

   7.2      ARBITRATORS; SELECTION OF NEUTRAL ARBITRATOR......................6

   7.3      ARBITRATION HEARINGS, PROCEDURES AND TIMING.......................7

   7.4      CHOICE OF LAW.....................................................7

                                        i


   7.5      AWARD AND ENFORCEMENT.............................................7

   7.6      PERFORMANCE PENDING ARBITRATION DECISION..........................7

   7.7      DEFINITION OF "PARTIES" FOR THIS SECTION..........................7


Section 8 - Joint Committee...................................................7

   8.1      PURPOSE...........................................................7

   8.2      DESIGNATION.......................................................7

   8.3      AUTHORITY.........................................................8

   8.4      DECISIONS.........................................................8

   8.5      RELATIONSHIP TO ARBITRATION.......................................8


Section 9 - General Provisions................................................8

   9.1      CONFIDENTIALITY...................................................8

   9.2      JOINT AND SEVERAL.................................................9

   9.3      ENTIRE AGREEMENT..................................................9

   9.4      SUCCESSORS AND ASSIGNS............................................9

   9.5      CONSTRUCTION......................................................9

   9.6      WAIVER OF CONSEQUENTIAL DAMAGES...................................9

   9.7      NOTICES...........................................................9


Section 10 - Signatures......................................................11



                        List of Attachments and Exhibits

           Attachment 1: Guarantee

           Exhibit 1: San Juan Mine Surface Reserves

           Exhibit 2: La Plata Mine Surface Reserves


                                       ii


                        Section 0 - Parties and Recitals
                        --------------------------------

This Coal Sales Agreement Buy Out Agreement ("Agreement") is dated August 31,
2001, to become effective on December 31, 2002, as provided herein, by and
between San Juan Coal Company, a Delaware corporation ("SJCC"), Public Service
Company of New Mexico, a New Mexico corporation ("PNM"), and Tucson Electric
Power Company, an Arizona corporation ("TEP") (PNM and TEP are referred to
collectively as "Utilities"), (with SJCC and Utilities herein sometimes
collectively referred to as "Parties").

Whereas, SJCC and Utilities are parties to the Coal Sales Agreement dated August
18, 1980 between SJCC and Utilities, as amended ("CSA"), which has a term
through 2017;

Whereas, Utilities have ongoing obligations under the CSA;

Whereas, SJCC and the Utilities desire to terminate the CSA and provide
compensation to SJCC for the Utilities' remaining obligations under the CSA;

Whereas, SJCC, San Juan Transportation Company, and Utilities are parties to the
Underground Letter Agreement dated August 31, 2000 ("UG Letter Agreement"); and,

Whereas, SJCC and Utilities are parties to the Underground Coal Sales Agreement
("UG-CSA") dated August 31, 2001.

NOW, THEREFORE, in consideration of the terms, covenants and agreements
contained in this Agreement, Utilities jointly and severally agree with SJCC as
follows:

                        Section 1 - Definitions and Term
                        --------------------------------

1.1      Effective Date

         Subject to Section 2.1 "Conditions Precedent", the Effective Date of
         this Agreement shall be December 31, 2002.

1.2      Outstanding CSA Obligations

         "Outstanding CSA Obligations" shall be defined as any payments, costs,
         audit adjustments (including 3rd party audits), or other obligations
         arising from or related to performance under the CSA prior to the CSA
         termination.

1.3      SJCC Costs

         "SJCC Costs" shall be defined as:

         A)       Any and all rentals, royalties, overriding royalties, other
                  retained interests, charges, fees and all other payments paid
                  or incurred by SJCC in connection with this Agreement;

         B)       Any Outstanding CSA Obligations; and,

         C)       Any and all actual costs incurred by SJCC (including
                  reasonable attorney fees and expenses) relating to all claims
                  other than those between Utilities and SJCC which arise from
                  the payment of CBOV as defined in Section 4.1 "CSA Buy Out
                  Value".

                                       1


1.4      Term

           This Agreement shall terminate after all payments have been received
           in full by SJCC in accordance with the terms of this Agreement and
           all obligations under this Agreement have been satisfied or otherwise
           resolved pursuant to Section 7 "Dispute Resolution".

        Section 2 - Conditions Precedent, Representations and Warranties
        ----------------------------------------------------------------

2.1      Conditions Precedent

           The Conditions Precedent to this Agreement becoming effective are:

         A)       Satisfaction of the conditions precedent contained in the
                  UG-CSA.

         B)       Final approval of this Agreement by the San Juan Fuels
                  Committee pursuant to the requirements of the San Juan Project
                  Participation Agreement dated as of October 27, 1999, to be
                  obtained no later than September 28, 2001, and written
                  notification of such approval to SJCC by the Utilities.

         C)       Execution of the Guarantee by the Guarantor in the form
                  attached to this Agreement as Attachment 1 and incorporated
                  herein, to be obtained no later than September 28, 2001, and
                  provided to Utilities by SJCC.

2.2      Representations and Warranties

         As of the execution of this Agreement and subject to satisfaction of
         the applicable conditions precedent described in this Agreement, each
         party warrants and represents that:

         A)       It is a corporation duly organized and in good standing in its
                  state of incorporation and is qualified to do business and is
                  in good standing in those states where necessary in order to
                  carry out the purposes of this Agreement;

         B)       It has the capacity to enter into and perform this Agreement
                  and all transactions contemplated in this Agreement, and that
                  all corporate actions required to authorize it to enter into
                  and perform this Agreement have been taken properly; and

         C)       This Agreement has been duly executed and delivered by it and
                  is valid and binding upon it in accordance with its terms.

                      Section 3 - Coal Reserves Bought Out
                      ------------------------------------

3.1      San Juan Mine Surface Reserves

         The San Juan Mine reserves shown for illustrative purposes on Exhibit 1
         "San Juan Mine Surface Reserves" (attached and incorporated by
         reference) are bought out by this Agreement. SJCC shall maintain
         records sufficient to identify these reserves.

                                       2


3.2      La Plata Mine Surface Reserves

         The La Plata Mine reserves shown for illustrative purposes on Exhibit 2
         "La Plata Mine Surface Reserves" (attached and incorporated by
         reference) are bought out by this Agreement. SJCC shall maintain
         records sufficient to identify these reserves.

                         Section 4 - SJCC Compensation
                         -----------------------------

4.1      CSA Buy Out Value

         The Utilities shall pay to SJCC [*], adjusted per Section 4.2
         "Inflation - Deflation Adjustment" ("CBOV"), on December 31, 2002, to
         buy out the value of the La Plata and Fruitland Capital Investment
         Elements and to extinguish any further obligations under the CSA.

4.2      Inflation - Deflation Adjustment

         A)       The amount of [*] will be adjusted for inflation according to
                  the following formula:

                           CBOV = [*] x D1 / D0

                  (1 and 0 are subscripts)
                  D1 and D0 are defined herein.

                  In no event shall the inflation-deflation adjustment cause
                  CBOV to be less than [*].

         B)       The "Inflation Index", calculated to three decimal places,
                  shall be equal to the sum of sixty-five percent (65%) times
                  the "Producer Price Index- Commodities for Construction
                  Machinery and Equipment (Series Id WPU112)" not seasonally
                  adjusted, as published by the United States Department of
                  Labor, Bureau of Labor Statistics ("Index"), plus thirty-five
                  percent (35%) times the "Implicit Price Deflator, Gross
                  Domestic Product", as published by the United States
                  Department of Commerce, Bureau of Economic Analysis
                  ("Deflator").

                  1)  D0 shall be the Inflation Index calculated using the most
                      recently published values for June 2000, for the Index
                      and Deflator described above.

                  2)  D1 shall be the Inflation Index calculated using the most
                      recently published values available for the date when the
                      payment is due, for the Index and Deflator described
                      above.

                  In the event that there is a revision of a base index figure,
                  the base index figure will be revised in accordance with
                  pertinent published instructions regarding such revision, or
                  if such instructions are not published, the base index figure
                  will be revised in a manner, which fairly reflects the
                  revision.

                                       3


                  In the event that publication of any of the indices specified
                  for use under this Section 4.2 (B) should be discontinued or
                  in the event the items or categories upon which such published
                  index is based should be so modified or changed as to make the
                  further use of such index inequitable, the Parties agree to
                  develop a mutually acceptable substitute index (either
                  published or compiled or arranged by the Parties).

4.3      Payment of CBOV

         A)       There will not be an invoice generated by SJCC for payment
                  made pursuant to Section 4.1.

         B)       Utilities agree to make an electronic funds transfer of CBOV
                  due to SJCC including all applicable taxes, to SJCC's
                  nominated account (to be nominated in writing by SJCC at least
                  60 days before the payment date) on or before the payment date
                  described herein.

                  Applicable taxes shall include any and all taxes (including
                  without limitation gross income, gross receipts, value added,
                  sales, use, occupation, franchise, personal property, stamp
                  and other taxes), levies, imposts, duties, charges or
                  withholdings of any nature whatsoever, together with any
                  interest thereon (any of the foregoing fees, taxes and
                  interest being for purposes hereof called "taxes") imposed by
                  any sovereign political or governmental authority or taxing
                  authority upon or in connection with SJCC's operation and with
                  any activities and transactions under this Agreement
                  (including reimbursements for SJCC Costs as described
                  hereunder) excepting only taxes which are measured by net
                  income (other than any such taxes measured by net income which
                  are imposed in lieu of taxes measured by gross income and
                  gross receipts).

         C)       Utilities shall provide SJCC with documentation of the
                  Inflation Index used to determine the payment amount with
                  notification of the electronic funds transfer.

4.4      Payment of SJCC Costs

         A)       Invoicing and Payment

         SJCC will invoice the Utilities for SJCC Costs. Invoices submitted by
         SJCC shall be due and payable by Utilities on the twenty-second (22nd)
         day of the month succeeding the month for which such invoice is
         submitted, or on the twelfth (12th) day after receipt of the invoice by
         Utilities, whichever date is later. Payment shall be made to SJCC by
         electronic funds transfer to such bank account as SJCC may from time to
         time designate.

         B)       Disputed Invoices

         In case any portion of any invoice concerning SJCC Costs is disputed,
         the undisputed amount shall be paid when due; provided however, that
         Utilities may also pay the disputed portion of such invoice without
         thereby waiving their right to contest such disputed portion. Disputed
         invoices for SJCC Costs shall be referred initially to the Joint
         Committee for resolution.

                                       4


         C)       Failure to Pay

         In the event Utilities fail to pay any amount due and not in bona fide
         dispute, SJCC shall be paid interest on all amounts owing under any
         invoice submitted hereunder which are not paid when due and payable,
         with said interest to be calculated at the Prime Rate as published in
         the Wall Street Journal for corporate loans posted by at least 75% of
         the nation's largest banks (or its equivalent) plus three percent (3%)
         but not in excess of the maximum rate of interest permitted by law and
         to be paid for the actual number of days elapsed since the invoice was
         due and payable. This right shall not be deemed an exclusive right or
         remedy.

         D)       Audits

         SJCC will keep books, records and accounts necessary to show all
         information required for purposes of this Section 4.4. Upon Utilities'
         request, SJCC shall supply Utilities, by report and/or with actual
         source documents, the information reasonably necessary to verify any
         invoice for SJCC Costs issued pursuant to this Agreement; provided,
         however, that SJCC shall not be required to disclose information which
         in the opinion of SJCC is of a confidential nature due to the
         relationship of such information to SJCC's existing or contemplated
         operations. In the event Utilities and SJCC are unable to agree that
         the invoice is calculated correctly, a verification of such invoice
         shall be prepared and certified by a nationally recognized firm of
         certified public accountants, to be selected by Utilities from a list
         of three (3) such firms submitted by SJCC, such verification to set
         forth all data reasonably necessary to verify that the invoice is
         calculated correctly. The findings of said verification shall be
         accepted by both Utilities and SJCC as final and binding with respect
         to that invoice. The accounting firm selected for any such verification
         shall be bound not to disclose and shall treat as confidential any and
         all proprietary information of SJCC furnished to or examined by such
         firm in connection with such audit. It is understood that such
         verification shall not provide Utilities with nor entitle Utilities
         access to SJCC's books or records.

         If any such verification discloses that a calculation error has
         occurred and that, as a result thereof, an amount is due to one or the
         other party, such amount shall promptly be paid to whom it is owed;
         provided, however, if there is a dispute relating to the validity of a
         charge or adequacy of a payment either party may submit such dispute to
         the Joint Committee. All expenses of any such requested verification
         shall be paid by Utilities. Invoices which are not contested by either
         party within twenty-four (24) months from the date of the Invoice shall
         be deemed to be correct and will not thereafter be subject to
         verification.

                          Section 5 - CSA Termination
                          ---------------------------

5.1      CSA Termination

         Upon receipt of the CBOV payment by SJCC as adjusted and in
         consideration of the terms and conditions set forth in this Agreement,
         the CSA and the associated Guarantee by BHP Minerals International Inc.
         are terminated and all obligations under the CSA are satisfied.

                                       5



                          Section 6 - SJCC Obligations
                          ----------------------------

6.1      SJCC Obligations

         SJCC shall use reasonable efforts consistent with law to minimize
         claims for costs referenced in Section 1.3(A) and to manage costs
         referenced in Section 1.3(C).

                         Section 7 - Dispute Resolution
                         ------------------------------

7.1      Matters To Be Arbitrated; Notice of Claims and Defenses;
         Party Arbitrator Designation

         Either party may demand final and binding arbitration of any dispute,
         claim or controversy arising out of or relating to this Agreement,
         performance or actions pursuant to this Agreement, or concerning the
         interpretation of this Agreement (whether such matters sound in
         contract, tort or otherwise and including without limitation
         repudiation, illegality, and/or fraud in the inducement) by giving
         written notice to the other party of all claims it desires to submit to
         arbitration; provided, however, that matters within the authority of
         the Joint Committee must be presented first to that committee for
         consideration. Disputes regarding the payment of CBOV shall be
         immediately subject to arbitration in accordance with this section. The
         notice shall include: (a) the demanding party's designation of a party
         arbitrator; and (b) a detailed statement of the facts and theories
         supporting the claims. The party on whom the arbitration demand is
         served shall have thirty days from receipt of the notice to respond in
         writing to the demand and to submit any additional claims it wishes to
         submit to arbitration at the same time. The response also shall
         include: (a) the designation of the party arbitrator for that party;
         and (b) a detailed statement of the facts and theories supporting the
         claims and/or defenses asserted. The party originally demanding
         arbitration shall reply in writing to any additional claims submitted
         within ten days from the receipt of response.

7.2      Arbitrators; Selection of Neutral Arbitrator

         Any party who fails to designate timely its party arbitrator shall
         forfeit its right to designate an arbitrator. If only one arbitrator is
         timely designated, that single arbitrator shall hear the dispute. If
         two arbitrators are timely designated, those arbitrators shall, within
         thirty days, either agree on the appointment of a third, disinterested
         arbitrator knowledgeable as to the subject matter involved in the
         arbitration or petition the Chief Judge of the United States District
         Court for the District of New Mexico for the appointment of a third
         arbitrator. The parties shall be equally liable for the reasonable fees
         and expenses of the neutral arbitrator hearing the dispute. The parties
         shall be responsible for the fees and expenses of their respective
         party-appointed arbitrator.

                                       6


7.3      Arbitration Hearings, Procedures and Timing

         All reasonable efforts will be made to hold a hearing on the claims
         submitted within sixty days after the appointment of the last
         arbitrator. In conducting the hearing, the arbitrators are directed,
         where feasible and where not inconsistent with the provisions of this
         paragraph, to adhere to the then-existing American Arbitration
         Association procedures and rules relating to commercial disputes.
         Unless otherwise agreed by the parties, the hearing shall be held in
         Farmington, New Mexico.

7.4      Choice of Law

         The arbitrators shall apply the laws of the State of New Mexico.

7.5      Award and Enforcement

         The decision or award of the arbitrators shall be given in writing
         within thirty days after the conclusion of the hearing. The arbitrators
         are authorized to award money damages, injunctive and declaratory
         relief and/or specific performance, if such relief in their opinion is
         appropriate. In any arbitration, each party shall bear its own costs,
         expenses, and attorneys' fees. The arbitrators do not have authority to
         award costs, expenses, or attorneys' fees to the prevailing party. The
         award or decision of the arbitrators shall be subject to review or
         enforcement in accordance with the New Mexico Uniform Arbitration Act,
         NMSA 1978 ss.ss. 44-7-1 et seq. Any party shall be entitled to recover
         reasonable attorneys' fees and costs incurred in enforcing any
         arbitration award or decision made pursuant to the arbitration
         provisions of this Agreement.

7.6      Performance Pending Arbitration Decision

         During the arbitration, unless otherwise ordered by the arbitrators,
         the parties agree to continued performance under this Agreement.

7.7      Definition of "Parties" for this Section

         For purposes of this Section 7, the Utilities shall be considered a
         single party. Specifically, and by example, the Utilities must act
         collectively to select their party arbitrator under Section 7.2
         "Arbitrators; Selection of Neutral Arbitrator".

                          Section 8 - Joint Committee
                          ---------------------------

8.1      Purpose

         The intent of the Parties in providing for a Joint Committee is to
         establish an orderly and continuing means of dealing with matters that
         may arise from time to time in carrying out the provisions of this
         Agreement. The Joint Committee shall have four (4) members.

8.2      Designation

         During the term of this Agreement, SJCC will, by notice to Utilities,
         designate two (2) individuals as its representatives on the Joint
         Committee, and Utilities will, by notice to SJCC, designate two (2)
         individuals as their representatives on the Joint Committee; and each
         such representative shall be authorized by the party(ies) by whom he is

                                       7


         designated to act on its (their) behalf with respect to matters herein
         specified to be responsibilities of the Joint Committee. A
         representative may not delegate his responsibilities to others, but
         Utilities, or SJCC, may designate an alternate to act when said
         representative is unavailable. Either Utilities, or SJCC, by notice to
         the other, may change the designation of its (their) representatives.

8.3      Authority

         The Joint Committee shall have authority and responsibility to address
         disputes arising from or related to this Agreement other than disputes
         regarding the payment of CBOV. The Joint Committee shall not have any
         authority with respect to disputes regarding the payment of CBOV and
         such disputes shall be immediately subject to arbitration.

8.4      Decisions

         Decisions by the Joint Committee shall require the unanimous approval
         of all representatives of the Joint Committee and shall be evidenced by
         the signatures of all said representatives.

8.5      Relationship to Arbitration

         In case agreement should not be reached among the representatives of
         the Joint Committee as to any of the matters referred to in Section 8.3
         "Authority" as responsibilities of the Joint Committee, such matters
         shall be forthwith submitted to and determined by arbitration as
         provided for in Section 7 "Dispute Resolution".

                         Section 9 - General Provisions
                         ------------------------------

9.1      Confidentiality

         The terms and conditions, including those dealing with compensation,
         set forth in this Agreement are considered by Utilities and SJCC to be
         confidential and proprietary information and none of the parties shall
         disclose any such information to any third party other than the
         attorneys, auditors and agents of Utilities, other owners of the San
         Juan Station, and SJCC, without the advance written consent of the
         other parties; provided however, disclosure may be made without advance
         consent where, in the opinion of counsel, such disclosure may be
         required by order of court or regulatory agency, law or regulation or
         in connection with judicial or administrative proceedings involving a
         party hereto, in which event the party to make such disclosure shall
         advise the other parties in advance as soon as possible and cooperate
         to the maximum extent practicable to minimize the disclosure of any
         such information, including, where practicable, deletion of portions of
         this Agreement relating to compensation, including, Section 4 "SJCC
         Compensation".

                                       8


         Utilities shall maintain with the owners of the San Juan Station other
         than the Utilities written confidentiality agreements that are
         acceptable to SJCC prior to the disclosure of the terms of this
         Agreement.

9.2      Joint and Several

         The Utilities' duties and obligations under this Agreement shall be
         joint and several.

9.3      Entire Agreement

         This Agreement supersedes all prior agreements and representations
         between the Parties, whether written or oral, with respect to the
         subject matter of this Agreement and is intended as a complete and
         exclusive statement of the terms of the agreement between the Parties
         with respect to the subject matter. Except as specifically set forth in
         this Agreement, no representations have been made to induce any of the
         Parties to enter into this Agreement.

9.4      Successors and Assigns

         This Agreement and all of the rights and obligations of the Parties
         described shall extend to and be binding upon, and shall inure to the
         benefit of, the respective successors and assigns of the respective
         Parties.

9.5      Construction

         The terms and conditions of this Agreement are the result of
         negotiation and drafting on an equal footing by the Parties and their
         legal counsel. This Agreement shall be construed evenhandedly and
         without favor or predisposition to any party.

9.6      Waiver of Consequential Damages.

         SJCC and the Utilities waive any recovery of consequential damages
         related to the breach of this Agreement.

9.7      Notices

         A)       Any notice, demand or request provided for in this Agreement,
                  or given or made in connection with this Agreement shall be in
                  writing, signed by an officer of the party giving such notice
                  and shall be deemed to be properly and sufficiently given or
                  made if sent by registered or certified mail, and if to SJCC,
                  addressed as follows:

                           San Juan Coal Company
                           300 West Arrington, Suite 200
                           Farmington, NM 87401
                           Attention: President

                  with a copy addressed as follows:

                           San Juan Coal Company
                           Post Office Box 155
                           Fruitland, NM 87416
                           Attention:  San Juan Mine Manager

                                       9




                  and if to Utilities, addressed as follows:

                           Public Service Company of New Mexico
                           Alvarado Square
                           Albuquerque, NM 87158
                           Attention:  Corporate Secretary

                  and

                           Tucson Electric Power Company
                           Post Office Box 711
                           Tucson, AZ 85702
                           Attention:  Secretary

         B)       Any party hereto may change its address for notice by so
                  advising the other Parties hereto in accordance with the
                  provisions of this Section 9.7. Any notice given in accordance
                  with the provisions of this Section 9.7 shall be deemed
                  effectively given as of the date of its deposit with the
                  United States Postal Service.

                                       10


                             Section 10 - Signatures
                             -----------------------

IN WITNESS WHEREOF, SJCC, and the Utilities, by their duly authorized
representatives, have entered into this Agreement.



         PUBLIC SERVICE COMPANY OF NEW MEXICO





         By: /s/ Patrick J. Goodman                                    8/29/01
             ----------------------------------------                  -------

              Patrick J. Goodman, Vice President                       Date







         TUCSON ELECTRIC POWER COMPANY





         By: /s/ Kevin Larson                                          8/31/01
             -------------------------------------------------         -------

              Kevin Larson, Vice President                             Date





         SAN JUAN COAL COMPANY





         By: /s/ John W. Grubb                                         8/29/01
             ----------------------------------------                  -------

              John W. Grubb, President                                 Date



                                       11