Attach to Exhibit 10.21



     Attached hereto is an English translation of the original Spanish version
of the Joint Venture Agreement between Comibol and ASC Bolivia LDC, regarding
the Choroma Concession.  The Company employed translators to translate the above
referenced agreement and based on this the undersigned believes that the
attached is a fair and accurate English translation of the above referenced
agreement.


                                         /s/ Keith R. Hulley
                                         -------------------
                                         Keith R. Hulley
                                         Director
                                         Apex Silver Mines Limited

                                         Date: August 29, 1997

 
                                                                   EXHIBIT 10.21


PROTOCOL No.244/97

FOR THE: JOINT VENTURE CONTRACT WRIT FOR THE DEVELOPMENT OF MINING ACTIVITIES;
SUBSCRIBED BETWEEN THE CORPORACION MINERA DE BOLIVIA (COMIBOL) REPRESENTED BY
ITS PRESIDENT DR. ALBERTO ALANDIA BARRON AND ITS CONTRACTS AND FINANCES MANAGER
LIC. LUIS ARNAL VELASCO; AND ASC BOLIVIA LDC REPRESENTED BY JOHNNY DELGADO
ACHAVAL.

In La Paz City, Republic of Bolivia, at fifteen thirty hours August fourteen
ninety seven, before me, lawyer MARIA ESTHER VALLEJOS H., SPECIAL NOTARY OF
MINES AND PETROLEUM and witnesses that at the end are named and sign the
document, presented themselves, on one side DR. ALBERTO ALANDIA BARRON with ID
1191230 Pt. and LIC. LUIS ARNAL VELASCO with ID 332387 LP, PRESIDENT AND MANAGER
OF CONTRACTS AND FINANCES RESPECTIVELY, FOR THE "CORPORATION MINERA DE BOLIVIA"
and on the other side ENG. JOHNNY DELGADO ACHAVAL with ID 39745 LP,
REPRESENTATIVE FOR "ASC BOLIVIA LDC," all full of age, able by right, neighbors
of this city, whom I certify to have identified and said: That, they agree to
convert into a public deed the WRIT that has been presented to me, together
with: ASC BOLIVIA LDC'S PROPOSAL, PAGES 5, 9, 10 AND 11, BOARD OF DIRECTOR'S
RESOLUTION NO. 1105/96, GENERAL BOARD OF DIRECTORS' RESOLUTION No. 1229/96,
SUPREME RESOLUTION No. 213601/94, POWER OF ATTORNEY No. 140/94, POWER OF
ATTORNEY NO. 205/94 AND POWERS WRIT No. 105/96, with literal contents as
follows:

WRIT.- CONT. GUC-DJ-352/96 SPECIAL NOTARY OF MINES:  In the public deeds
- ----
register under your charge, please insert a Joint Venture Contract for the
development of mining activities subscribed between the CORPORACION MINERA DE
BOLIVIA (COMIBOL) and ASC BOLIVIA LDC company, with the clauses and conditions
given below:

FIRST.- THE JURISTIC PERSON OF THE PARTIES AND THE LEGAL STATUS OF THE
SUBSCRIBING PERSONS.

 
1.1.  This Joint Venture Contract is subscribed by, on one side, the CORPORACION
      MINERA DE BOLIVIA, known from now on as COMIBOL, a decentralized Autarkic
      Entity of the State, created by S.D.3196 dated October two, nineteen fifty
      six, enacted as Law on October twenty nine, nineteen fifty six, with its
      own juristic person and full administration autonomy, exercising the
      Administration and Higher Direction of all the mining deposits, dumps,
      tailings and slags, establishments, facilities, camps, complementary
      property in general, without exception, constituting the state owned
      mines, either these be as a result of the mines' nationalization or
      purchased after it

1.2.  On the other hand, the company subscribing the CONTRACT IS ASC BOLIVIA 
      LDC, a stock company, SUBSIDIARY OF ANDEAN SILVER CORPORATION LDC, an
      international mining company constituted in the Great Cayman Islands, 
      through constitution certificate


 
      dated September seven, nineteen ninety five, whose original copy has been
      certified by the Bolivian Consulate in London (England) on the 14th of the
      same month and year, a legally constituted subsidiary in Bolivia, through
      Public Deed No 49, granted by the Special Notary oF Mines in La Paz on
      November ten, nineteen ninety five, registered in the General Registry of
      Commerce and Stock Companies, under Registration No 09-037169-01 dated
      December six, nineteen ninety five and in the Unique Taxpayers' Register
      with RUC No 7836635.

1.3. LEGAL STATUS OF THOSE SUBSCRIBING.

     COMIBOL'S subscribes the Contract represented by its PRESIDENT, DR. ALBERTO
     ALANDIA BARRON, who exercises the legal representation of the entity by
     virtue of S. D 23727 dated February elevens nineteen ninety four, by
     official appointment given by Supreme Resolution No 213601 dated February
     sixteen of the same year and exercising the powers conferred to him by
     COMIBOL'S General Board of Directors, through Resolution No 896194 dated
     March fifteen. Nineteen ninety four, as well as LIC. LUIS ARNAL VELASCO,
     MANAGER OF THE CONTRACTS AND FINANCES UNIT, appointed in such position
     through COMIBOL'S General Board of Directors' Resolution No 860/94 dated
     June thirteen, ninety four and empowered through Special Power of Attorney
     by the said PRESIDENT OF COMIBOL, through instrument No. 222/94 dated July
     eleven, nineteen ninety tour before a Public Notary in La Paz in charge of
     Dra. Nelly Alfaro and Registered in the Notary of Mines in La Paz, under No
     205 dated July twenty eight, nineteen ninety four; which will be enclosed
     in the corresponding public deed

14.  Subscribes the Contract, in representation of ASC BOLIVIA LDC, by virtue of
     the Limited Power of Attorney conferred to him, Mr. JOHNNY DELGADO ACHAVAL,
     as its truly and legal agent and proxy, through instrument granted on March
     seven, nineteen ninety six before Notary Public in the Cayman Islands,
     George M Shortridge, certified by the Bolivian Consul in London (England),
     documents that have been judicially translated from English into Spanish,
     by orders from the Fifth Civil Judge in La Paz, and registered before the
     Special Notar of Mines of this Capital City, under No 105 dated April
     first, nineteen ninety six and registered in the General Register of
     Commerce under item No 798 of Book 07-0 on the eighth of the same month and
     year. Special power of attorney that, as a whole, will be enclosed in the
     corresponding Public Deed.

SECOND.- BACKGROUND FOR THE CONTRACT.
 
2.1. Applying the Supreme Government's Mining Policies and within the framework
     of the legal provisions in force, valid for this matter, COMIBOL has
     publicly invited national and foreign Mining Companies, interested in the
     EXPLORATION with option to the EXPLOITATION and posterior MARKETING of the
     non-developed mining deposits, among others, those from the SUD CHICHAS
     Province zone in the Department of Potosi, so that they present proposals
     to that end, and the Terms of Reference and the legal and administrative
     requirements for the Public Tender have been widely advertized. In order to
     guarantee the total legality of the public tender's results, as well as the
     greatest efficiency in the evaluation of the proposals to be presented,
     independent consulting firms of recognized technical experience and company
     solvency were equally invited. The 

                                       2

 
     evaluation's result made by BEHRE DOLBEAR & COMPANY INC., the selected
     independent consulting firm, as can be seen in the Report dated September
     nineteen ninety six, chose ASC BOLIVIA LDC for the awarding of the JOINT
     VENURE CONTRACT for the Mining Concessions described later on and that form
     part of ANNEX "A" of the Contract, a report that has been approved by
     COMIBOL'S Board of Directors through Resolution No. 1105/96 dated February
     six, nineteen ninety six and that at the same time authorized the
     negotiations for the respective CONTRACT with ASC BOLIVIA LDC.

THIRD.-DEFINITIONS.

The following definitions are established in this Contract. in an enunciative
but not limitative manner: 

3.1. AREA GRANTED.- MINING concessions belonging to COMIBOL included in
     ------------
     Contract and whose total surface area is 125 hectares. The concessions of
     the AREA GRANTED are individually described in page five of the Technical-
     Economical Proposal presented by ASC BOLIVIA LDC and in ANNEX "A" of the
     Contract. COMIBOL at the express and written request by ASC BOLIVIA LDC can
     formulate petitions or grant complementary areas neighboring with the AREA
     GRANTED, in which case ASC BOLIVIA LDC will prepare a specific work plan
     and will guarantee a minimum investment in the same conditions as those for
     the AREA GRANTED.

3.2. INVESTED CAPITAL.- Are all the expenses and investments made by ASC 
     ----------------
     BOLIVIA LDC for the exploration and development of the mineral reserves,
     preparation of pre-feasibility and feasibility studies. basic and hi-detail
     engineering designs; purchase, transport and import of equipment, machinery
     and materials: installation of all the mine equipment and machinery,
     mineral concentrating and refinery plants, workshops, laboratories,
     warehouses, offices. etc.. building of camps and buildings, tailings and
     waste accumulation systems, energy distribution systems, energy plants,
     safety systems, water catchment and accumulation systems; etc. and starting
     of the production operations, according to generally accepted accounting
     principles.

3.3. MINING CONCESSIONS.- Set of mining properties (AD. 33 of the Mining Code),
     ------------------
     in which the activities established in the Contract can be performed.

3.4. MARKETING COMMISSION FEES.- Payment in money for the administration of the
     -------------------------
     sale of the mineral metals produced by ASC BOLIVIA LDC. These commission
     fees do not form part of the marketing costs.

3.5. PRODUCTION COSTS.- Are all the operational expenses made by ASC BOLIVIA LDC
     ----------------
     during the minerals production process up to the obtaining of the saleable
     or exportable final products in the mine, either these be mineral
     concentrates or metals, according to generally accepted accounting
     practices and principles.

                                       3

 
3.6.  OVERHEADS.- Are all the expenses made by ASC BOLIVIA LDC for the
      ---------                                                       
      administration and direction of the Joint Venture Contract, different from
      the production costs, according to generally accepted accounting practices
      and principles.

3.7.  MARKETING COSTS. - Are all those that are done in order to convert the 
      --------------- 
      minerals in metals, by the smelter or refining company; they include
      metallurgical deductions, treatment, smelting and refining expenses,
      analysis, assays, arbitrations, penalties and other deductions and
      expenses directly related to the conversion process to marketable metals.

3.8.  DEPRECIATION. - A deduction made according to Bolivian laws. due to the 
      ------------
      reduction, wear and value loss of the capital assets, for their 
      replacement.

3.9.  DELIVERY. - The date on which COMIBOL will deliver physically and 
      --------
      officially the AREA GRANTED to ASC BOLIVIA LDC. The physical delivery will
      be documented by the detailed minutes to be drawn up in some place of the
      AREA GRANTED. The minutes will be signed by the parties' representatives
      appointed for that purpose, with a prior written notice between them. The
      delivery will be done not later than thirty (30) days after the CONTRACT
      is signed.

3.10. OPERATIONAL CASH FLOW. - It is the gross value of sales' expenses minus 
      ---------------------
      the realization expenses, marketing commission fees, marketing costs,
      production costs and administrative costs, excluding the financial
      expenses, depreciation, deferred expenses and taxes.

3.11. REALIZATION EXPENSES.- Are all those directly related to the transport of
      ---------------------
      concentrates or final products from the mine up to the smelters; they
      include losses, road, air and sea transport tees, transport insurance.
      handling, port expenses and other related. these realization expenses do
      not form part of the Marketing Costs.

3.12. DEFERRED EXPENSES.- Are all the payments or charges made and whose
      -----------------
      application is deferred until certain terms laid down previously are met
      or the application period for the expense has expired.

3.13. FINANCIAL EXPENSES.- Are all the debt services for banking credits or from
      ------------------
      financing entities hired by ASC BOLIVIA LDC for the compliance and
      execution of the Joint Venture Contract.

3.14. TAXES.- Are all the national, municipal taxes, or of any other type,
      -----
      already created or to be created by Law, applied to the mining operations
      developed bY ASC BOLIVIA LDC, as a result of this Contract.

3.15. PAY BACK PERIOD.- Any period, either being the initial one or a posterior
      ---------------
      one, including the month starting in which an expense has been made for
      capital improvements and prior to the first day of the following month to
      that in which ASC BOLIVIA LDC has recovered all the costs and expenses for
      capital improvements from the Cash Flow.

                                       4

 
3.16. PRODUCT(S).- All the materials, minerals, precipitates from mining
      ----------
      resources, concentrates, core, and any other product or sub-product,
      originated in the AREA GRANTED.

3.17. PAY BACK.- Means the date on which ASC BOLIVIA LDC'S shareholders have
      --------
      received all the costs and expenses for capital improvements from the Cash
      Flow, really made and registered according to generally accepted
      principles in Bolivia. The calculation will be done ate the end of each
      ASC BOLIVIA LDC'S fiscal year. Nonetheless, COMIBOL'S participation,
      mentioned in paragraph 11.1.2, will be applied from the moment the pay
      back is finished.


3.18. SALE CROSS VALUE.- Are the payments to be received by ASC BOLIVIA LDC,
      ----------------
      from natural or juristic third persons, for the sale of refined metals or
      concentrates, produced during the exploitation period, from which all the
      expenses and costs established in point 3.7 will be deducted.


3.19. NET SMELTER RETURN.- It is the gross value for the sale of the minerals,
      ------------------
      minus the marketing costs and the realization expenses.


FOURTH.- APPLICABLE LAWS.
 
4.1. This Contract is subscribed and is regulated by the legal provisions that
     in a mere enunciative but not limitative manner are given below:

     Arts. 136 and 138 of the Poll Const. of the State, S.D. 3196 (2-10/52), L.
     (2910/56), L. 843 (2005/86), S.D. 22407 (11-0 1/901 S.D. 22408 (11-01190),
     L. 1182 ( 1 7-09/90), L. 1 297 (27-11/9 1 ), S.D. 23059 (13-02/92), L. 1243
     (11-04/92), L. 1333 (29-04/92), its regulations enacted through S.D. 24176
     dated 8/12/95, S.D. 23214 (21-07/92), S.D. 23230-A (30-07/92) and other
     legal provisions on the matter or to be enacted in the future. This Joint
     Venture Contract was approved by COMIBOL'S Board of Directors, through
     Resolution No. 1229/96 dated 27-09-96.


FIFTH. - THE JOINT VENTURE CONTRACT, TRADE NAME AND ADDRESS.

5.1.  The Joint Venture Contract, constituted by this document. known from now 
      on as CONTRACT, does not compromise the patrimony of any of the associated
      parties nor it affects h1 any way the juristic person of the hiring
      parties; it neither constitutes a partnership, nor it establishes an
      independent juristic person. It is not established in the CONTRACT, for
      the associated parties, a jointly and severally nor limited responsibility
      for the acts, contracts and obligations each party could male, celebrate
      and assume in the execution and compliance of this CONTRACT.

5.2.  As a result from the CONTRACT, ASC BOLIVIA LDC does not acquire any
      property rights in the civil regime nor as mining concessionaire in the
      mining regime, on the soil nor the underground of the AREA GRANTED, nor on
      the water nights, servitudes and uses, access roads, camps, constructions
      or any other facilities that could exist.

                                       5

 
5.3.  In the terms and conditions stated in the CONTRACT, COMIBOL grants ASC
      BOLIVIA LDC. in an express manner, the exclusive exploration rights, the
      option to enter into a exploitation phase, once the first exploration
      phase is completely finished, as well as the marketing of the minerals to
      be exploited over a surface are of One Hundred and Twenty Five (135)
      hectares of the Mining concession "CHOROMA", located in Tupiza County, Sud
      Chichas Province of the Department of Potosi , whose detail is expressed
      in ANNEX "A" of the CONTRACT.

5.4.  This exclusive right, in the conditions stated in the CONTRACT, is the
      sole and total COMIBOL'S contribution to the Joint Venture Contract agreed
      upon in this document, and comibol does not acquire any obligation nor
      responsibility for the execution and compliance of the CONTRACT. It also
      means that COMIBOL, during the time the CONTRACT is in force, will not
      reduce, cede, affect nor compromise its rights and interests on the
      deposits contributed to the joint venture, in any measure nor for any
      motive, guaranteeing ASC BOLIVIA LDC the peaceful possession, the use and
      enjoyment of the mining concessions object of the CONTRACT.

5.5.  The parties, by mutual agreement, convene in appointing this Joint Venture
      Contract with the trade name of COMIBOL-ANDEAN-CHOROMA R.C., with legal
      address in La Paz City, Campos Street No. 265, Telephone 433800, Fax
      (5912) 433737.

SIXTH.- OBJECT OF THE CONTRACT.
 
6.1.  Based on the background given before, COMIBOL and ASC BOLIVIA LDC, through
      this document agree to subscribe a Joint Venture Contract for the
      exploration, and option to exploit, concentrate, refine and smelt without
      any reserve and the marketing of the mineral products, metals and sub-
      products that could be exploited in the deposits located in the AREA
      GRANTED, under the technical conditions described in ASC BOLIVIA LDC'S
      proposal and accepted by COMIBOL, as laid down in its proposal and that
      constitutes annex "b" of this CONTRACT. documents that, without being
      registered, are an inseparable and constitutive part of this CONTRACT.

6.2.  The activities object of this CONTRACT, comprise the identification and
      development of reserves, design of the mining operation, rational and
      efficient exploitation of the mineral resources, optimization of the
      treatment and metallurgical recovery processes, preparation of the
      respective technical and economical feasibility projects and, in general,
      the application of modern technology and an efficient management in the
      performance of the mining operations, as well as comply with the
      environmental obligations established by law, according to clause
      seventeenth of the CONTRACT.

SEVENTH.- TERM FOR EXPLORATION
 

7.1.  The maximum term for the Exploration Period will be of Five (5) years
      starting from the physical and official delivery of the AREA GRANTED in
      this CONTRACT, by 

                                       6

 
      COMIBOL to ASC BOLIVIA LDC, this delivery will be documented through
      detailed minutes drawn up in the site or where the parties agree to, and
      must be signed by the officials appointed to that effect, with the
      presence of a competent authority.

7.2.  The said term of five (5 ) years for exploration. is divided in three (3 )
      phases as follows: 

      FIRST PHASE with a duration of twenty four (24) months.
      SECOND PHASE with a duration of twenty four (24) months. 
      THIRD PHASE with a duration of twelve ( 12) months. 
      TOTAL SIXTY (60) months, equivalent to FIVE (5) YEARS.

7.3.  The First Phase is compulsory and thus its strict observance is guaranteed
      by ASC BOLIVIA LDC, according to that laid down in Clauses 9.1 and 9.2 of
      this CONTRACT.

7.4.  During the First Phase. ASC BOLIVIA LDC, will execute the Work Program
      appearing in page 6 to page 8 of its accepted and awarded Proposal, a work
      plan that will form part of this CONTRACT without the need of its
      registration, ASC BOLIVIA LDC con explore the whole of the mining
      concessions or part of them at its will, but in any sector, the work plan
      will be executed faithfully and fully. COMIBOL, at the written and express
      request by ASC BOLIVIA LDC, can formulate mining petitions or grant
      complementary areas within the two (2) kilometers neighboring the area
      granted, in which case ASC BOLIVIA LDC will formulate a specific work plan
      and will guarantee a minimum investment to be made in such complementary
      areas that will be subject to the same conditions established for the work
      plan as well as the minimum investment for the AREA GRANTED.

7.5.  ASC BOLIVIA LDC, during the First Phase, can anticipate the conclusion of
      the twenty four (24) months term, under the express condition of having
      finished the execution of the Work Program committed for this Phase and,
      as a result, can enter into the other Exploration Phases or exercise
      immediately its option rights to enter into the Exploitation Phase in the
      areas its studies would have determined as positive. In this case, the
      Bank Guarantee Certificate for the Compliance of the CONTRACT will be
      returned by COMIBOL, within sixty (60) days once the First Exploration
      Phase is finished. The observance of the Work Plan, as well as the start
      of the Exploitation will be irrevocably verified by COMIBOL, which will
      issue the detailed reports of one and other situation, within sixty (60)
      days.

7.6.  ASC BOLIVIA LDC, at any time during the First Phase, but only after having
      complied with the Minimum Work Program and not later than the last day of
      the maximum term for the Phase can definitely suspend the Exploration in
      the areas object of this CONTRACT and withdraw from the Joint Venture
      Contract, in the case that the CONTRACT will be canceled of full right on
      the date of ASC BOLIVIA LDC'S notice to COMIBOL of its decision. Should
      ASC BOLIVIA LDC hadn't fulfilled with the Minimum Work Program, COMIBOL
      will cash the Bank Guarantee Certificate for Contract Compliance, without
      any right to recourse, claim nor any exception ASC 

                                       7

 
      BOLIVIA LDC could oppose against COMIBOL, either judicially or outside the
      court. The Joint Venture Contract will, thus, become null and without any
      legal validity.

7.7.  The simple reduction of the surface area of any of the areas, forming part
      of the AREA GRANTED according to that recommended by the studies done by
      ASC BOLIVIA LDC, will not mean the suspension of the exploration to the
      ends expressed in the previous point 7.6 and ASC BOLIVIA LDC is obliged to
      continue the execution of the Work Plan committed in its proposal on the
      areas selected as attractive, which will be done until the conclusion of
      the term established for the First Phase.

EIGHT. - EXPLORATION INITIAL PAYMENTS.

8.1. ASC BOLIVIA LDC, according to the public tender s terms of reference, will
     pay COMIBOL the following exploration initial payments scale.

     FIRST PHASE three 57/100 American Dollars ($us 3.57) per hectare on the
     -----------
     whole surface of the AREA GRANTED, that is to say, 125 hectares.


8.2.  The payments described and stated in the previous Point (8.1), will 
      be paid on the 125 hectares or mining properties, within thirty (30) days
      after the physical delivery of the concessions by COMIBOL to ASC BOLIVIA
      LDC. Any reduction in the surface area of any of the concessions of the
      AREA GRANTED, either be during a maximum term of 24 months, or of the
      Second or Third Phases, will not give rise to a return or reimbursement of
      the Exploration Initial Rates agreed upon in Numbers 8.1, 8.3 and 8.4 of
      this CONTRACT, by COMIBOL to ASC BOLIVIA LDC and the amounts paid will be
      consolidated in COMIBOL'S favor .

8.3.  SECOND PHASE: One Hundred and Nineteen 05/100 American Dollars ($us
      119.05), per hectare on the extension of the concessions that at the start
      of the Second Phase, decides to explore within the teen of 24 months
      established for this Phase. The discontinuity of the exploration
      operations is admitted within a same mining concession. The First Phase
      area can also be reduced or request COMIBOL, or perform mining petitions
      to the State or larger extensions should there be tree land, according to
      that explained in the Twenty Sixth Clause of this CONTRACT and according
      to that laid down in the last part of Clause 7.4 of the CONTRACT, ASC
      BOLIVIA LDC is obliged to notify COMIBOL of any areas' reduction of the
      AREA GRANTED with a thirty (30) days notice prior to the ending of the
      proceeding Phase Term. It will also notify of any anticipation in the term
      due to having entered into the Exploitation Phase under the same
      conditions.

8.4.  THIRD PHASE: Five Hundred and Ninety Five 24/100 American Dollars ($us
      595.24) per hectare as an Exploration Initial Rate on the mining
      concessions' extensions, that at the start of the Third Phase decides to
      explore within TWELVE ( 12) MONTHS.
      In this phase, the exploration operations discontinuity is admitted within
      the same concession. The exploration area can also be reduced with
      relation to the First and 

                                       8

 
      Second Phases or request COMIBOL or make mining petitions to the state for
      a larger extension should there be free land according to that laid down
      in Clause Twenty Sixth of this COMIBOL. ASC BOLIVIA LDC is obliged to
      notify COMIBOL of any areas reduction in the AREA GRANTED, with no less
      than THIRTY (30) DAYS notice before the end of the Second Phase. It will
      also notify COMIBOL of the anticipated conclusion of this Phase's term
      when it decides to enter into the Exploitation Phase.

8.5.  All the Payments for the Exploration Initial Rates established in Points
      8.1, 8.2, 8.3 and 8.4 previous, will by done by ASC BOLIVIA LDC before the
      start of the corresponding Phase and within a maximum of thirty (30) days,
      in COMIBOL'S of flees in La Paz city, receiving the corresponding fiscal
      receipts for tax purposes.

NINTH.- MINIMUM GUARANEED INVESTMENT DURING THE FIRST EXPLORATION PHASE.

 
9.1.  According to the Public Tender's Tends of Reference, ASC BOLIVIA LDC
      accepts and is compelled to make an guaranteed Minimum Investment during
      the First Phase of the Exploration period Of Two Hundred Thirteen Thousand
      00/100 American Dollars ($us 213,000.00) pledged in the Budget and
      Investment Plan, page 9 of its Proposal.

9.2.  As a result, ASC BOLIVIA LDC guarantees the Minimum Total Investment of
      the amount established in the previous Point, through the presentation to
      COMIBOL of a Bank Guarantee Certificate for Contract Compliance, issued
      irrevocably in favor of COMIBOL by BHN MULTIBANCO Bank of LA PAZ CITY,
      under No. 10004176 dated 05-02-97 for Forty Two Thousand Six Hundred
      00/100 American Dollars ($us 42,600.00), equivalent to twenty percent
      (20%) of the amount of the minimum investment pledged.

9.3.  Whilst ASC BOLIVIA LDC, during the First Phase, is malting the
      corresponding investments, can request COMIBOL the presentation of the
      original Guarantee Certificate, substituting it simultaneously with a new
      certificate covering the remainder of the guarantee or the investment not
      yet made, and/or the corresponding tend until, within twenty four (24)
      months. Or before if the First Phase of the exploration term is
      anticipated, the minimum investment pledged has teen made according to
      Clauses 7.3 and 9.1 of this CONTRACT. The Guarantee Certificates exchange
      will be done within maximum 30 days, with a prior COMIBOL'S verification
      and acceptance that the investments made by ASC BOLIVIA LDC, through
      documented evidence, with attesting and independent auditor's report.

9.4.  If once the last day of the twenty four (24) month period for the First
      Phase has expired, there would be a balance of investment not made by ASC
      BOLIVIA LDC, COMIBOL can cash the Bank Guarantee Certificate valid at that
      date, and ASC BOLIVIA LDC won't be able to oppose a recourse nor an
      exception of any nature.

                                       9

 
9.5.  The Exploitation Phase can only be entered into once the amount for the
      minimum investment has been really and totally invested by ASC BOLIVIA
      LDC, either this occurs at the end of the term appointed for the First
      Phase of prior to any of the terms established for each one of the Phases,
      which will be decided by ASC BOLIVIA LDC for having determined a positive
      sector in any of the concessions.

9.6.  The Three Phases forming part of the Exploration Period. have the purpose
      of developing mineralogical reserves. Design of the treatment plants and
      the preparation of a rational and mechanized exploitation plan, design and
      optimization of the treatment processes and metallurgical recovery, the
      preparation of technical economical feasibility projects and the adoption
      of appropriate environmental protection measures. pollution control and
      soil recovery, objectives that are described in the World; program of ASC
      BOLIVIA LDC'S proposal.

9.7.  Thus, it is agreed that, if ASC BOLIVIA LDC considers attractive certain
      areas to start in them the Exploitation Phase, at any time within the
      established periods for any of the Three Phases, but if and when the Work
      Program of the Exploration Program of ASC BOLIVIA LDC'S proposal has been
      complied with entirely as described in ANNEX "B" of this CONTRACT and the
      minimum investment has been totally made, apart from the technical-
      economical feasibility study, ASC BOLIVIA LDC can enter into the
      exploitation phase, and must notify COMIBOL of this decision or the
      purposes of the verification of the compliance of the beforesaid
      conditions and the financial-accounting management of the COMIBOL'S share
      established in ASC BOLIVIA LDC'S Proposal.

9.8.  If ASC BOLIVIA LDC does not exercise its Exploitation option rights at the
      end of the Exploration Period, either if it occurs at the expiry of any of
      its Phases determined in the contract. or before, by ASC BOLIVIA LDC'S
      decision, the latter is obliged to present COMIBOL, without any charge or
      reimbursement of any nature, all the technical information, drawings,
      maps, designs, calculations and reports.

9.9.  The suspension or no performance of the compulsory minimum investment
      pledged by ASC BOLIVIA LDC, withal the times and conditions stated in this
      CONTRACT, will mean for all legal purposes, the statement by ASC BOLIVIA
      LDC of its decision to withdraw from the Joint Venture Contract.
      constituted in this contract and COMIBOL, without the need to comply with
      a prior special formality, will cash the Bank Guarantee Certificate
      presented by ASC BOLIVIA LDC, without any right to recourse, exception or
      protest any by the latter, either judicially or out of court.

9.10.  As a result, all the extension of the AREA GRANTED, object of this
       CONTRACT will be reverted to COMIBOL'S total domain within ninety (90)
       days maximum, ASC BOLIVIA LDC must withdraw all the equipment and
       machinery employed until then, assuming the costs and risks. The
       buildings, access roads and other facilities adhered to the ground that
       would have been installed will remain for COMIBOL benefit as
       improvements, without the right to a reimbursement nor any type of
       compensation and the CONTRACT will be extinguished purely and simply. The
       equipment and machinery 

                                       10

 
        adhered to the ground can also be withdrawn if and when the foundations
        nor the wall to which they are adhered to, are not destroyed. This tasks
        will be executed under ASC BOLIVIA LDC'S exclusive risk and charge.

9.11.   If the exploration areas cover only part of the AREA GRANTED, they must
        conform squares parallel to the perimeter of such concessions.

9.12.   The areas that in tune are rejected by ASC BOLIVIA LDC' at the end of
        each exploration Phase, will be excluded from the CONTRACT and will be
        everted to COMIBOL exclusive domain. In turn, the new areas will be
        annexed to the CONTRACT, in the conditions stated in Clauses 3. i and
        7.4 of the CONTRACT.

TENTH.- TIIE EXPLOITATION PERIOD
 
10.1.   Once all the stated conditions in this CONTRACT are complied with, for
        the first and, in its case, for the Second and/or Third Phases of the
        Exploration Period by ASC BOLIVIA LDC, without any exception, not later
        than the last day of the maximum term for each phase, ASC BOLIVIA LDC
        trill notify COMIBOL about the areas it has selected in order to start
        the Exploitation period of the deposits contained therein, which will
        mean the exercise of its option rights, which will be notified to
        COMIBOL through a notarized letter, enclosing the technical-economical
        feasibility studies for the exploitation to be done and the marketing of
        the products.

10.2.   COMIBOL will issue its approval of the feasibility study or its
        observations to it, within ninety (90) days. COMIBOL can pose
        observations due to technical and economical reasons, the same all be
        transmitted to ASC BOLIVIA LDC for their solution. if ASC BOLIVIA LDC
        dissents from COMIBOL'S opinion, the dispute will be resolved via the
        arbitral procedures established in Clause Twenty Third of this CONTRACT.

10.3.   When ASC BOLIVIA LDC exercises its exploitation option rights, the
        parties will not be subject to any negotiation, limiting themselves to
        the compliance of the provisions in this CONTRACT.

10.4.   Before the Exploitation Period is started, ASC BOLIVIA LDC is empowered
        to establish the non-attractive areas and that will be rejected, the
        same will be reverted of right to COMIBOL'S whole domain and will be
        automatically excluded from this Joint Venture Contract.

10.5.   COMIBOL will exercise its full and unrestricted right and administrative
        powers on the areas rejected.

ELEVENTH. - COMIBOL'S SHARE OF THE EXPLOITATION RESULTS.
 

11.1.   COMIBOL'S share during the exploitation period is established as
        follows, according to ASC BOLIVIA LDC'S fourteen pages' Proposal

                                       11

 
11.1.1.  During the recovery period of the invested capital by ASC BOLIVIA LDC
         in the construction, installation and starting stage of production
         operations, ASC BOLIVIA LDC will pay COMIBOL an income equivalent to
         Five percent (5%) of the Positive Operational Cash Flow, according to
         the definition given in Clause Three, Point 3 10 of this CONTRACT.

11.1.2.  After the repayment of the initial investment, ASC BOLIVIA LDC will pay
         COMIBOL Fifteen percent ( 1 Who) of the Positive Operation Cash Flow as
         defined in Clause Three. Point 3 10 of this CONTRACT.

11.1.3.  In case ASC BOLIVIA LDC makes new investments for the expansion of
         perations or for the change of method or processes, excluding the
         replacement of assets, COMIBOL share will come down again to Five
         percent (5%) of the Positive Operational Cash Flow, during the recovery
         period for the new investments.

11.1.4.  The periodicity of the shares' payments by ASC BOLIVIA LDC to COMIBOL
         will be done every three months, with annual settlements or adjustments

11.2.  It is expressely agreed that COMIBOL during all the time this CONTRACT
         is in force will have the right to supervise, verify and control the
         regularity of the financial processes described in the proceeding
         points 11 1 1, 11 1 2, 11 1 3, 11 1 4 and 11 1 5, through the
         accounting analysis of ASC BOLIVIA LDC'S documents, in order to
         establish exactly COMIBOL'S share, and ASC BOLIVIA LDC is obliged to
         disclose to COMIBOL the complete and authentic documents so that the
         financial and accounting revisions be effective ASC BOLIVIA LDC is also
         compelled to employ generally accepted accounting principles, for the
         accounting of its financial and marketing operations the supervision,
         verification and control for the operations accounting, will be done by
         comibol in ASC BOLIVIA LDC'S offices and will be executed periodically,
         according to that determined by the Administration Committee in the
         Internal Regulations approved by the parties.

TWELVETH. - CONSTRUCTION, INSTALLATION, STARTING AND OPERATION STAGES.

12.1.    The Construction. Installation and Starting of the Operations as a
         whole, will not exceed Three (3) years starting as of the date ASC
         BOLIVIA LDC notifies COMIBOL as stated in point 10.1 of Clause Tenth of
         this CONTRACT, unless force majeure defined later on in this CONTRACT.

12.2.    During the Exploitation Period, ASC BOLIVIA LDC will hold the exclusive
         administration and will run all the risks of the operations, with
         absolute autonomy in managerial decision mailing. With the same reaches
         and risks will also have the exclusive

                                       12

 
          administration and autonomy in the marketing of the minerals it
          produces, without any limitation, either be locally or through
          exports.

12.3.    COMIBOL will not be held responsible at all for the development or the
         financial results of the operations, its performance will be limited to
         the punctual perception of its share in the Cash Flow and its share in
         the coordinating, information and supervision organisms.

12.4.    Nonetheless. the hiring parties agree that the administrative expenses
         of the joint venture can not exceed Five percent (5%) of the production
         direct costs. Equally, it is also stated that the marketing commission
         and the realization costs can not exceed' as a whole, Two percent (2%)
         of the Net Smelter's Return.

12.5.    ASC BOLIVIA LDC will establish and execute a minerals marketing system
         that will allow an efficient, transparent management, guaranteeing the
         nonexistence of eventual benefits within or outside the country, for
         the benefit of one of the parties to the detriment of the other.

12.6.    The purchase of equipment, machinery, materials, facilities and raw
         materials by ASC BOLIVIA LDC will be done in such manner that the
         interests of the parties will not be affected and in particular
         COMIBOL'S share.

THIRTEENTH. - TERM OF THE CONTRACT.
 

13.1.    This Joint Venture Contract will have a term of Forty (40) Years,
         starting as of the physical and official delivery of the areas stated
         in this CONTRACT BY COMIBOL TO ASC BOLIVIA LDC. This term will be
         renewed in the same contract conditions for just one more time, with a
         prior technical and economical justification, if ASC BOLIVIA LDC
         expresses, in writing, its will to do it. The stated term includes the
         exploration period, either be in its entirety (5 years) or less, if asc
         bolivia ldc enters into the exploitation period beforehand according to
         that laid down in Clause 8.4 of the CONTRACT.

FOURTEENTH.- INVESTMENTS AND FINANCING.
 

14.1.    ASC BOLIVIA LDC is empowered to finance on its account and risk the
         exploitation operations, either be with its own resources or front
         others.-COMIBOL will not acquire at any time any type of obligation
         related to such financing, whose service will be exclusively in charge
         of ASC BOLIVIA LDC.

14.2.    The previous popovers are translated in that ASC BOLIVIA LDC is obliged
         and pledges to perform all the necessary investments in order to
         implement into the operations modern technology, services, machinery,
         equipment, implements, materials, facilities, constructions and such
         like, as well as assume the commitments that will allow a rational
         exploitation of the mineralogical deposits of the AREA GRANTED, object
         of this CONTRACT.

                                       13

 
14.3.    The investments' regime, initial as well as future, will respect
         invariably and at all times, that stated in Clauses Eleventh of this
         CONTRACT, relative to COMIBOL'S share of the results, regime that will
         remain unvariable during the whole term of the CONTRACT.

FIFTEENTH.- LABOR RELATIONS.

15.1.    The hiring and administration of the workforce, technicians and
         employees during the exploration stage, as well as during the
         exploitation stage is of the absolute and total responsibility of ASC
         BOLIVIA LDC, and it is of its entire responsibility the compliance with
         the Labor General Law, its Regulatory Decree and related legal
         provisions and complementary in force or to be enacted, as well as
         those provisions relative to social security, professional risks,
         employer's and employee's contributions, whilst COMIBOL is totally
         exempt of responsibility, and can not be demanded in any lawsuit of
         labor nature nor in any civil, penal, tax, fiscal coactive, social
         coactive nature, nor administrative, as an result of acts or omissions
         resulting from the execution of this CONTRACT by ASC BOLIVIA LDC.

15.2.    COMIBOL will deliver ASC BOLIVIA LDC the AREA GRANTED, object of this
         CONTRACT free from encumbrance or obligations of labor or legal
         character.

SIXTEENTH. - FORCE MAJEURE.

16.1.    None of the hiring parties can demand of the other the compliance with
         the obligations acquired in this CONTRACT, when the compliance has been
         delayed, hindered or impeded by causes not blamed on the obliged party.
         Such causes will constitute those of force majoure or fortuitous cases,
         as earthquakes, flooding, fire, strikes declared illegal, civil
         commotion, factors that can affect transport in general, governmental
         prohibitions and catastrophes in general, according to that laid down
         by articles 379 and 380 of the Civil Code.

         It will also be considered as a force majeure a sustained fall for over
         six (6) months in the price of minerals to be produced under the
         minimum established by the feasibility study, if and when such
         situation causes the stoppage of the extraction of the minerals or
         production operations. If these operations continue even under such
         market conditions, the force majeure cause will disappear.

16.2.    The period during which ASC BOLIVIA LDC will be hindered to normally
         comply with this CONTRACT, will be added to the term stated in Clause
         Thirteenth.

16.3.    Should a force majeure cause happens, ASC BOLIVIA LDC is obliged to
         notify COMIBOL within the next five days, describing the nature of the
         happening and its effects.

                                       14

 
16.4.    The omission of this notice will maintain COMIBOL indemnity in the
         regularity of its share in the results and h1 the accounting of the
         time period.

16.5.    When the force majeure causes are of such nature and magnitude that the
         objectives of this CONTRACT and the joint venture in general are
         substantially and permanently harmed or are affected in a continuous
         manner for more than six months. the hiring parties can agree upon the
         temptation of the CONTRACT.

SEVENTEENTH.- ENVIRONMENTAL STANDARDS AND ENVIRONMENTAL MANAGEMENT PLAN
 

17.1.    During the performance of the works and during the life of this
         CONTRACT, ASC BOLIVIA LDC will be subject to the environmental
         requirements, that is to say, the allowable pollution limits in force
         in the country, established by Law No. 1333 dated April Twenty Seventh
         nineteen ninety two and the regulations enacted by S.D. 24t76 dated
         December nineteen ninety five and other provisions in force or to be
         enacted in the future.

17.2.    ASC BOLIVIA LDC will draw up the environmental management plan,
         starting from an initial audit. in order to avoid or mitigate the
         environmental impact, as established by the next Clause 17 4, as well
         as the work plan for the execution and closure of activities.

17.3.    The environmental management mainly comprises the recovery of the
         exploited areas, in order to control the erosion, stabilize the ground
         and protect the waters and the atmosphere, perform the treatment of
         waste materials and eliminate in a safe manner the tailings, mill
         tailings and dumps.

17.4.    When ASC BOLIVIA LDC starts its activities, it will determine the
         environmental liabilities that could exist in the deposits, object of
         this CONTRACT, through the performance of the respective environmental
         audit, according to that established in Clause 17.8.1.

17.5.    ASC BOLIVIA LDC will be held responsible for the environmental
         pollution flows originated in its mining works and through the
         accumulation of wastes during the performance of its activities. in
         turn, COMIBOL will be responsible for the accumulations and flows
         coming from mining works, done prior to this CONTRACT, established in
         the environmental audit according to the previous Clause 17.4.

17.6.    When ASC BOLIVIA LDC does not comply with that determined in Clause
         17.4, it will assume the exclusive responsibility for the flows and
         accumulations resulting from the old and new mining works.

17.7.    ASC BOLIVIA LDC will pay for damages, to those affected by the
         environmental pollution generated by the accumulations and flows coming
         from its mining works with an absolute exclusion of COMIBOL.

                                       15

 
17.8.    The environmental management, particularly in order to establish the
         polluting accumulations and flows. will be controlled by ASC BOLIVIA
         LDC in the following manner:

         17.8.1.  Through the drawing up of an initial environmental audit done
                  by ASC BOLIVIA LDC, to be done during the first six (6) months
                  of the Exploitation period. Starting from the audit, ASC
                  BOLIVIA LDC will prepare, in the next to months, the
                  environmental management plan.

         17.8.2.  Should COMIBOL has its own audit and ASC BOLIVIA LDC accepts
                  it, it will be applicable and ASC BOLIVIA LDC must draw up the
                  environmental management plan within four (4) months, starting
                  from the date of the affidavit corresponding to this CONTRACT.

         17.8.3.  Through environmental audits for the compliance of obligations
                  and the establishment of responsibilities, resulting from the
                  environmental management plan, to be done every three years by
                  specialized companies or entities of national or international
                  prestige, hired and paid by ASC BOLIVIA LDC.

         17.8.4.  Through annual reports on the environmental management
                  prepared by ASC BOLIVIA LDC.

         17.8.5.  COMIBOL can ask ASC BOLIVIA LDC the environmental information
                  it considers necessary and can perform on its own the audits
                  it deems necessary.

         17.8.6.  The environmental management according to that established in
                  Point 17.4, comprises the recovery of the exploited areas in
                  order to reduce and control erosion, stabilize the grounds and
                  protect the waters and the atmosphere, perform the treatment
                  of waste materials and eliminate in a safe manner the
                  tailings, mill tailings and dumps.

         17.8.7.  The joint venture will not be able to be resolved as long as
                  the terms given in this Clause are not complied with. On the
                  other hand, ASC BOLIVIA LDC will continue having the
                  responsibilities corresponding to its environmental
                  management, according to the law, once the CONTRACT is
                  dissolved.

         17.8.8.  In order to avoid controversies ASC BOLIVIA LDC will timely
                  and sufficiently inform the representatives of the local
                  populations, on the aspects related to the protection of the
                  environment and will try to interest them in the environmental
                  repair works.

                  Also, ASC BOLIVIA LDC must comply with the legal requirements
                  regarding the information to third parties and others that
                  correspond.

EIGHTEENTH.- NON-EXISTENCE OF SOLIDARITY.

                                       16

 
18.1.    It is expressly agreed that the hiring parties do not assume a joint
         solidarity of any nature with respect to the obligations contracted by
         any of them for the compliance of the obligations resulting from this
         CONTRACT, unless that eventually and by free will and in an express
         manner any of them assumes such obligations, which will be truly
         recorded in a notarized document.

18.2.    It is also expressly convened that this document contains all the
         agreements, specifications and provisions agreed by the hiring parties,
         and none of them will be obliged nor related to the other by any
         statement, pledge or verbal or written agreement that is not expressly
         incorporated in this CONTRACT.

NINETEENTH -QUALITY OF THE CONCESSIONAIRE.

19.1.    According to that laid down by Art. 197 of Law No. 1243 for the
         Updating of the Mining Code, ASC BOLIVIA LDC does not acquire property
         rights nor a mining concession at all on the soil or underground of the
         mining concessions forming part of the AREA GRANTED.

19.2.    Nonetheless, COMIBOL grants in favor of ASC BOLIVIA LDC the operational
         exclusiveness during the exploration phase as well as during the
         construction, installation, starting and exploitation and the annexing
         of facilities, equipment, machinery and other complementary assets,
         such as constructions, access roads, water and right of way servitudes
         uses and customs of the said concessions, understanding as
         exclusiveness the fact that during the life of this CONTRACT none of
         COMIBOL'S rights on such concessions. servitudes, uses and customs will
         be affected, reduced nor impaired in any way, guaranteeing the quiet
         and peaceful possession, use and enjoyment of the same, protecting all
         the investment and development of ASC BOLIVIA LDC'S activities,
         defending such rights against incursions, invasions and other
         disturbances by third parties, either they be trade unions,
         cooperatives, entities or persons, appealing to the means and resources
         given by the laws of the Republic.

TWENTIETH.- COORDINATION, INFORMATION AND SUPERVISION OF THE
JOINT VENTURE.
 

20.1.    ASC BOLIVIA LDC will have under its exclusive and autonomous control
         and responsibility the management of all the exploration and
         exploitation operations, without any exclusion nor limitation, with the
         restrictions established in the laws of the Republic.

20.1.    Nonetheless, this Joint Venture Contract will have as coordination,
         information and follow-up organization, a COMMITTEE constituted at the
         signing of the CONTRACT, that will be composed by four (4) members, two
         (2) of them appointed by COMIBOL, and the other two (2) by ASC BOLIVIA
         LDC, whose emoluments will be paid by the party appointing them.

                                       17

 
20.3.    The COMMITTEE will constitute the main relationship means between
         COMIBOL AND ASC BOLIVIA LDC during the life of the CONTRACT. The main
         responsibility of the COMMITTEE will be to maintain the best managerial
         relations between the parties and to contribute so that any
         disagreement, that could come up between them, be discussed and
         resolved in a concerted manner.

20.4.    The COMMITTEE'S attributions, among others that it will determine. will
         be:

         a)  Approve during its first meetings an internal bylaw that will norm
             the COMMITTEE'S activities;

         b)  Verify the proper compliance of the conditions of this CONTRACT;

         c)  Create a communications system between ASC BOLIVIA LDC'S managerial
             organism and the committee in order to ease the flow of the
             relations between both organisms;

         d)  Formulate the recommendations it considers opportune for the better
             compliance of the CONTRACT'S objectives, not meaning that such
             recommendations are compulsory for the parties;

         e)  Gather all the technical, administrative and financial information
             in order to conserve it within reach for its inspection and study
             by the parties;

         f)  Recommend the execution of technical audits of the performed
             operations by virtue of this CONTRACT, taking care that such audits
             at no time hinder or interfere with the operations or impairs asc
             bolivia ldc's administrative autonomy. These audits will be paid by
             the party requiring them;

         g)  Periodically formulate the recommendations that are considered
             necessary, with relation to the development of ASC BOLIVIA LDC's
             operational plans.

TWENTY FIRST.- BOARD OF DIRECTORS.

21.1.    Within fifteen days of having signed this CONTRACT, the parties will
         organize a BOARD OF DIRECTORS.

21.2.    This BOARD OF DIRECTORS will be formed by representatives from both
         parties, COMIBOL and ASC BOLIVIA LDC, with equal number of members,
         whose emoluments will be paid by the party appointing them.

21.3.    The BOARD OF DIRECTORS will meet whenever necessary and called by the
         president at his/her own initiative or at the request of the parties.

                                       18

 
21.4.    The President of the BOARD OF DIRECTORS will be appointed by the
         members of the BOARD OF DIRECTORS at the first ordinary meeting of such
         organism.

21.5.    The responsibilities of the BOARD OF DIRECTORS are, apart from those it
         decides:

         21.5.1.  To determine the general policies of the joint venture;

         21.5.2.  To approve the financial statements of the joint venture;

         21.5.3.  To approve the hire of external independent auditors so they
                  will submit an opinion on the joint venture's annual financial
                  statements;

         21.5.4.  To know and approve the recommendations with regards to the
                  plans, projects and reports put before them by the COMMITTEE;

         21.5.5.  The joint venture's BOARD OF DIRECTORS will be the relations
                  organism between COMIBOL'S board of directors and ASC BOLIVIA
                  LDCA'S executive organisms, for everything concerning to the
                  running of the joint venture.

         21.5.6.  To know the audited financial statements done by external and
                  independent auditors of optimum quality, at the end of each
                  fiscal year.

21.6.  The BOARD OF DIRECTORS' duties will, at no time, interfere nor impair the
       administrative autonomy of ASC BOLIVIA LDC, on the joint venture's
       operations during the exploitation stage and marketing of the minerals.

21.7.  The BOARD OF DIRECTORS will carry a chronological and circumstantial
       minutes of every and all their meetings, and the former will be signed by
       those present.

TWENTY SECOND.- TAX AND CONTRIBUTIONS REGIME.
 

22.1.  All the taxes and liens applicable to the mining industry, as well as
       those applicable to the import of equipment, machinery, raw materials,
       materials and other assets, to the marketing of minerals locally and for
       export, in force at the date of the signing of this CONTRACT or that will
       be enacted in the future will be exclusively paid by ASC BOLIVIA LDC and
       its effects on COMIBOL'S corresponding share will be regulated by that
       stated in clause eleventh of this CONTRACT.

22.2.  Those taxes applicable to profits each party will obtain from the mining
       operation, object of this CONTRACT will be the entire responsibility of
       each of them, without any other responsibility for the other party.
       
                                       19

 
22.3.    The contributions to entities of Social Security and Complementary
         Funds or similar other ones existing or to be created, are of the
         exclusive responsibility and charge of ASC BOLIVIA LDC, with COMIBOL'S
         ABSOLUTE EXCLUSION.

TWENTY THIRD.- RESOLVING OF CONFLICTS BETWEEN PARTIES AND
ARBITRATION
 

23.1.    All controversies and claims that could arise between parties with
         regards the interpretation or execution of this CONTRACT, will be tried
         to resolve them amicably and fast between such parties. in case that
         they can not resolve them through mutual negotiations within sixty (60)
         days, any of the hiring parties can request the matter under conflict
         to be put before an arbitrer.

23.2.    In such circumstances, the controversy or interpretation will be
         resolved through settlement and/or arbitration according to the
         Regulations given by the National Chamber of Commerce's Settlement and
         Arbritation Center in La Paz (Bolivia) that, forming part of this
         Clause, the parties declare to know and accept. The Center will appoint
         the arbitrer from among the members of the Arbitral Body of such
         Settlement and Arbitration Center belonging to the aforementioned
         Chamber.

23.3.    No recourse will proceed against the Arbitrer's resolutions, thus the
         parties expressly resign to put it forward.

23.4.    The arbitration costs will be paid by the loser in the Arbitral 
         Decision.

TWENTY FOURTH.- CONTRACT TRANSFERRAL TO A THIRD PARTY.
 

24.1.    This Joint Venture Contract is a result of the award to a proposal
         formulated by ASC BOLIVIA LDC to COMIBOL involving the evaluation of
         certain technical, financial conditions and of the industrial
         capability and competence of the bidder. Nonetheless, ASC BOLIVIA LDC
         is empowered to incorporate into the contract's execution one or more
         members of known prestige and capability in the mining industry, or in
         the investments and financial branch, as well as transfer or subrogate
         but only partially their share in the CONTRACT to third parties, but
         without this meaning nor representing the total of their rights, share
         or obligations resulting from this CONTRACT. To that effect, the
         previous conditions stated as follows must be complied with:

24.2.    To this effect, it will request the prior and written authorization
         from COMIBOL, providing all the details demonstrating the suitability
         of the collective or individual persons that are pretended to be
         incorporated or those that will partially substitute ASC BOLIVIA LDC'S
         participation.
         
24.3.    COMIBOL reserves itself the right to assess the industrial and or
         financial sufficiency of the entity or person acquiring or is
         subrogated the partial share of ASC BOLIVIA LDC in the CONTRACT, with
         the right to veto if that or this does not have the required

                                       20

 
         conditions to the effect, with the sole obligation to give the concrete
         and reasonable motives restricting its acceptance. the third parties
         that could be incorporated to the joint venture contract, will assume
         the obligations, that as members, are stated in this CONTRACT.

24.4.    Any modification to the partial participation or share of ASC
         BOLIVIA LDC in this contract, by virtue of having obtained it through a
         public tender under special conditions, either be the incorporation of
         new members, transfer of rights, subrogation of rights or other
         contractual forms, the rights and shares corresponding to COMIBOL
         stated in this CONTRACT won't be able to be altered, modified, reduced
         nor affected.

TWENTY FIFTH.- RESCISSION OF CONTRACT
 

25.1.    During the exploration phases, COMIBOL will be able to rescind the 
         CONTRACT unilaterally, in the following cases:

         25.1.1.  Nonfulfillment of the initial payments by ASC BOLIVIA LDC for
                  each phase, which should be done within the first thirty (30)
                  days;

         25.1.2.  Nonfulfillment in executing the work program and minimum
                  investment pledged by ASC BOLIVIA LDC for the first
                  exploration phase, in which case the bank guarantee
                  certificate presented by ASC BOLIVIA LDC to COMIBOL will be
                  cashed in. and COMIBOL will give notice to ASC BOLIVIA LDC
                  furnishing the motives.

25.2.    In case the contract is terminated for any reason, during the
         Exploration Phase, all the improvements made by ASC BOLIVIA LDC in the
         areas of the CONTRACT, will stay behind for the benefit of the
         concessions, object of the former, without any charge for COMIBOL, with
         the exception of the tools, equipment, vehicles, materials and those
         facilities liable to be withdrawn that have not been adhered to the
         ground, all of which will be able to be freely withdrawn by ASC BOLIVIA
         LDC.

         All the technical information related to the explored areas, together
         with the charts, studies, calculations and complementary details, will
         also go as COMIBOL'S property, without any charge to it.

25.3.    The CONTRACT can also be terminated due to the following causes:

         25.3.1.  If the CONTRACT has expired, if it hadn't been extended
                  according to that laid down in Clause Thirteenth;

         25.3.2.  By mutual agreement of the hiring parties;

         25.3.3.  By ASC BOLIVIA LDC'S unilateral decision, when certain
                  circumstances appear that make unviable the exploitation in
                  rentable economical conditions.

                                       21

 
         25.3.4.  When the construction, installation and starting of the
                  operations exceed Three (3) years since the notification by
                  ASC BOLIVIA LDC to COMIBOL announcing its exercise of right to
                  option, unless there are force majeure causes.

         25.3.5.  When the force majeure causes are produced, such as defined in
                  Clause Sixteenth of this CONTRACT.

25.4.    In case or termination of this CONTRACT for any of the motives stated
         in this CONTRACT, either be during the exploration period or in the
         exploitation phase, ASC BOLIVIA LDC will be obliged to comply with the
         delivery of the studies and other information in the next ninety (90)
         days.

TWENTY SIXTH. - EXCLUSION AREA.
 

26.1.    ASC BOLIVIA LDC can not formulate petitions nor perform mining
         activities, either by itself or through and intermediary, in an area of
         two (2) kilometers from the perimeter of the concession object of this
         CONTRACT, unless there is an express authorization from COMIBOL. In any
         case, the petition made infringing this prohibition, will be considered
         as done for and for COMIBOL'S benefit.

26.2.    COMIBOL also won't be able to perform mining activities, either by
         itself or through an intermediary, in an exclusion area of one
         kilometer from the perimeter of the concessions object of this
         CONTRACT, unless the parties agree to the contrary.

TWENTY SEVENTH.- OPTION TO PURCHASE.
 

27.1.    At the definitive closure of operations due to the CONTRACT'S expiry,
         ASC BOLIVIA LDC grants COMIBOL the option rights, for a period of
         ninety (90) days, for the purchase of its rights and tangible assets of
         the joint venture, in equal opportunities as other interested parties.

27.2.    COMIBOL and ASC BOLIVIA LDC will appoint an expert appraiser in charge
         of establishing the price of the assets, using as basis for the
         appraisal, the market value.

27.3.    If COMIBOL decides to exercise its option rights, it must notify so of
         its decision to ASC BOLIVIA LDC through a notarized letter, within the
         term established in Point 27.1.

27.4.    The payment of the price will be done within the following sixty (60)
         days after the notice provided in the previous point, is given.

TWENTY EIGHT.-CONTRACT'S CONSTITUTIVE DOCUMENTS.

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28.1.    Are part of this CONTRACT and will be inserted in the corresponding
         Public Deed the following documents.

         a)  Supreme Decree No. 213601 dated February sixteenth nineteen ninety
             four.

         b)  COMIBOL'S board of directors resolution no. 1105 dated February six
             nineteen

         c)  General Administration Power of Attorney conferred to Dr. Alberto
             Alandia Barron No. 1-10 awarded in the Notary of Mines in La Paz on
             May seventeenth nineteen ninety four.

         d)  Special Power of Attorney conferred to Lic. Luis Arnal Velasco,
             registered in the Notary of Mines in La Paz, under No. 205 on July
             twenty eight nineteen ninety four.

         e)  Special Power of Attorney conferred to Mr. Johnny Delgado Achaval,
             registered in the Notary of Mines in La Paz, under No. 105 on April
             first nineteen ninety six, registered in the Commerce General
             Register, Entry 728, Book 07-0, the same month and year.

         f)  COMIBOL'S board of directors resolution no. 1229 dated September
             twenty seven nineteen ninety six.

         g)  Pages 5, 9 10 and 11 of ASC BOLIVIA LDC'S proposal.

TWENTY NINTH.-MINING LICENSES.
 

29.1.    During the Exploration Phase, the mining licenses on all the areas
         forming part of the mining concessions of the AREA GRANTED will be in
         charge of COMIBOL.

29.2.    Starting from the date ASC BOLIVIA LDC notifies COMIBOL that it will
         make use of its option right, the mining licenses on the areas declared
         as positive by ASC BOLIVIA LDC and in which the Exploitation Phase will
         be developed, will be paid by ASC BOLIVIA LDC on behalf of COMIBOL and
         the receipts will be presented by ASC BOLIVIA LDC to COMIBOL since they
         are documents representative of its concessionaire right. this payment
         won't be compensated nor reimbursed by COMIBOL nor by the joint venture
         and will be done exclusively by ASC BOLIVIA LDC.

THIRTIETH.- OFFICIAL REGISTRATION OF THE CONTRACT.
 

30.1.    The official registration's expenses for this CONTRACT, together with
         the ANNEXES and corresponding documents, will be paid by ASC BOLIVIA
         LDC, at the Special Notary of Mines in La Paz City

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30.2.    ASC BOLIVIA LDC is obliged to present COMIBOL Three (3) Affidavits of
         the officially registered CONTRACT, without any charge for COMIBOL,
         within sixty (60) days after the writ is signed.

THIRTY FIRST.- CONSENT AND ACCEPTANCE.
 

         31.1.  We, DR. ALBERTO ALANDIA BARRON, PRESIDENT OF THE CORPORACION
                MINERA DE BOLIVIA (COMIBOL) and LIC. LUIS ARNAL VELASCO, MANAGER
                OF THE CONTRACTS AND FINANCE UNIT OF THE CORPORACION MINERA DE
                BOLIVIA (COMIBOL), both of full age, neighbors of this city,
                with i.d. no. 1191230 pt. and no. 332387 l.p., respectively,
                able by right, on one side, and MR. JOHNNY DELGADO ACHAVAL, in
                representation of ASC BOLIVIA LDC, of full age, neighbor if this
                city, with i.d. no. 39745 l.p., ably: by right, give our full
                consent and accept every and each of the clauses, terms and
                conditions of this CONTRACT, to which we give full validity as
                Private Document between parties, whilst it is converted into a
                public deed, pledging to a faithful and strict compliance,
                subscribing it in La Paz City, on the Twenty first of November
                nineteen ninety six.- And you, Special Notary of Mines will add
                all the rest of safety and style clauses.

     Signed FOR CORPORACION MINERA DE BOLIVIA: Lic. Luis Arnal Velasco MANAGER
     OF CONTRACTS AND FINANCES.  Dr. Alberto Alandia Barron.-
     PRESIDENTE.
     Signed FOR ASC BOLIVIA LDC: Mr. Johnny Delgado Achaval AGENT AND PROXY.
     Signed.- Dr. Jorge Eyzaguirre Duran.- RUC 02199106.- C. Ab. 0157.- LEGAL
     ADVISOR COMIBOL. -

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