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Exhibit 4.15

PROFESSIONAL SERVICES CONTRACT, ENTERED INTO
BY AND BETWEEN THE COMPANY "MINERA SAN XAVIER", S.A. DE C.V., REPRESENTED BY MR.
SERGIO ENRIQUE LOPEZ BRIONES (HEREINAFTER REFERRED TO AS "MSX"), AND THE COMPANY
"FIREX", S.A. DE C.V., REPRESENTED BY MR. JORGE MENDIZABAL ACEBO (HEREINAFTER
REFERRED TO AS "FIREX"), ACCORDING TO THE FOLLOWING REPRESENTATIONS AND CLAUSES:

R E P R E S E N T A T I O N S

[English Translation of Spanish Language
Document]

I.          
Of "MSX":

> a)
>   To be a Mexican company, duly incorporated, according to the laws of our
>   country as evidenced in the public deed number 50,650, dated March 18th,
>   1994, granted before the attest of Mr. Jorge Alfredo Dominguez Martinez,
>   Notary Public number 140, of the city of Mexico, Federal District, and
>   inscribed in the Public Registry of Property and Commerce of the city of San
>   Luis Potosi, S.L.P., with the number 21,947, page 206, volume 227 of
>   Societies, Powers and Commerce.
>   b)
>   To have amongst its corporate purposes, the industry of mining- metallurgic in
>   general.
>   c)
>   To have its representative, the necessary faculties to enter into this
>   contract on behalf of MSX, as shown in the public deed number 33,434, volume
>   915, dated March 7th, 2003, granted before the attest of Mr. Jose
>   Maria Morera Gonzalez, Notary Public number 102 of the of Mexico, Federal
>   District, and that such faculties have not been modified or revoked to this
>   date.
>   d)
>   To have its domicile in the city of San Luis Potosi, capital of the State with
>   the same name.
>   e)
>   To be its Federal Contributors Registry: MSX-940318-C41.

II.        
Of FIREX:

> a)
>   To be a Mexican company, duly incorporated according to the laws of our
>   country, as evidenced in the public deed number 6, volume fourteen, dated July
>   31st, 1998, granted before the attest of Mr. Leopoldo de la Garza
>   Marroquin, Notary Public number 36 of the city of San Luis Potosi, S.L.P., and
>   inscribed in the Public Registry of Property and Commerce of the same city,
>   with the number 29,004, page 169, volume 380 of Societies, Powers and
>   Commerce.

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> b)
>   To have amongst its corporate purposes, the assistance in all type of
>   engineering and/or technology, as well as the counseling and supervision to
>   industrial companies.
>   c)
>   To have its representative the necessary faculties to enter into this contract
>   on behalf of FIREX, as evidenced in the public deed described in paragraph a)
>   of its representations, and that such faculties have not been modified and/or
>   revoked.
>   d) To have its
>   domicile located in the city of San Luis Potosi, capital of the State with the
>   same name.
>   e) To be its
>   Federal Contributors Registry: FIR-980731-TY2.

III.        Of the parties:

> a) To ratify the
>   content of their respective representations and to acknowledge the personality
>   and legal capacity with which they enter into this contract.
>   b)
>   To accept regulate their contractual relationship according to the terms,
>   conditions and scope of this document, in accordance to the content of the
>   same, granting their free will, not existing deceitful representations, error,
>   bad faith, nor any other act or omission that would induce the parties to
>   enter this agreement that they would not otherwise have made; the parties
>   therefore, grant the following:

C L A U S E S

FIRST.- SCOPE OF THE CONTRACT.MSX hires the services of FIREX with the purpose that the latter assists the
first throughout the development of the mining project of Cerro de San Pedro,
located in the Municipality of the same name, in the State of San Luis Potosi;
services that the latter agrees to perform, appointing for such effect Mr. Jorge
Mendizabal Acebo as advisor, acting as General Director of MSX, and in
accordance to the services set forth in the unique attachment of this contract.

SECOND.- TERM OF EFFECTIVENESS.The present contract shall be effective for six (6) months, counted from the
date of its signature, term which can be either increased or terminated in
anticipation, if formally negotiated by the parties.

THIRD.- PROFESSIONAL FEES.MSX shall pay FIREX for the services described in clause first, the monthly fee
of US$5,000.00 (five thousand dollars 00/100 USCy) plus the Added Value Tax,
upon receipt of the corresponding invoice, in its equivalent in Mexican
currency, at the rate published by BANXICO on the day the payment is due.

FOURTH.- MECHANISM OF PAYMENT.MSX shall pay the corresponding professional fees, through a cheque bearing the
name of FIREX, S.A. DE C.V., and/or through electronic transfer to the cheque
account that the General Director indicates. The payments will be made on the 15th
day of each month, or the previous working day, if the 15th is not a
working day.

FIFTH.- OTHER EXPENSES.The expenses, such as traveling expenses in which FIREX incurs, will be charged
to MSX, according to the politics established by the latter for such effect; in
any case, MSX shall pay and/or reimburse FIREX and/or the General Director, as
requested by these, the corresponding amounts, within the next five (5) days
following the date of the request.

SIXTH.- OBLIGATIONS OF THE PARTIES.

> A)     Of MSX:

1. To pay the
  professional fees to its counterpart, on time and according to the terms
  established in this contract.

2. To supervise
  the correct performance of the services object of this contract, through the
  person(s) designated for such effect.

3. The rest of the
  obligations appointed by this contract and/or its attachment.

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> B)     Of FIREX:
>   1.
>   To perform the services efficiently and in accordance to the applicable laws
>   and customs, as well as to the professional ethics.
>   2.
>   To respect the confidentiality to which it compromises by this contract,
>   regarding the services object of the same and/or the information provided by
>   MSX, or that derives from the contractual relationship.
>   3.
>   To inform MSX, timely and in writing, periodically or when requested, as the
>   parties agree, of all the services and/or activities carried out.
>   4.
>   The rest of the obligations appointed by this contract and/or its attachment.

SEVENTH.- CONFIDENTIALITY.Any information obtained by FIREX and/or by the General Director during and as a
consequence of this contract, will be strictly confidential. All the reports,
files, drawings, maps, data and any other document that MSX provides to FIREX
and/or to the General Director, or obtained, developed or prepared by the latter
according to this contract, shall be considered to be property of MSX.

EIGHTH.- EXCEPTIONS REGARDING THE
CONFIDENTIALITY.It shall not be deemed as
confidential the information already in the public domain, or .that result
evident to a technician on the subject, or the information that must be
disclosed by legal disposition or by judicial order. It shall not be deemed as
information of public domain, or disclosed by legal disposition, that
information that is provided to any authority by a person who possess it as
industrial secret, when he/she provides it with the purpose of obtaining
licenses, authorizations, registries, or any other acts of authority.

NINTH.- LABOR RESPONSIBILITY.
The work performed by FIREX, through the General Director,
according to this contract, shall be considered as that of a professional;
therefore the latter shall not be considered, in any time and under no
circumstances, as an employee of MSX, not existing consequently, between these
two, a labor relationship.

TENTH.- TERMINATION.The present contract can be terminated in anticipation for any of the following
causes:

> A)
>   For the total or partial impossibility of the General Director to continue
>   performing the services to which he has committed by this document, or
>   B)
>   By mutual agreement of the parties, in writing.

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ELEVENTH.- RESCISSION.
The present contract can be rescinded administratively, without
need of judicial declaration, for any of the following causes:

> A)
>   The delay or lack of payment of the professional fees, in the terms referred
>   to in clauses third and fourth of the present document, and/or
>   B)
>   The non-fulfillment by any of the parties, of any of the obligations imposed
>   by the present contract.

TWELFTH.- PREVIOUS NEGOTIATION OF CONFLICTS.In case that any controversy arises, the parties agree
to manifest in writing to its counterpart, their inconformity, obtaining prove
of its receipt or any other reliable proof of such declaration, giving each
other 30 days, counted from the date of the receipt of such notice, to sort out
and resolve their differences.

THIRTEENTH.- JURISDICTION AND ARBITRATION.

> A)
>   Jurisdiction.-For everything related to the
>   interpretation, fulfillment and execution of the stipulations of this
>   agreement, the parties submit to the jurisdiction of the Mexican legislation
>   on this matter, specifically to the established in the civil codification of
>   the State of San Luis Potosi, waiving expressly to any other jurisdiction that
>   for reasons of their present or future domiciles may correspond.
>   B)
>   Arbitration.-In case that the parties could not
>   resolve their differences according to the previous paragraph, they shall
>   resort to a procedure of arbitration, which decision shall be final. The
>   mechanism of dispute resolution according to this clause shall be as follows:
>   (i) the arbitration shall be of strict law, in the city of San Luis Potosi,
>   S.L.P.; (II) the procedure shall be governed according to the rules that the
>   Mexican Arbitration Centre (CAM, for its abbreviation in Spanish) has issued
>   at the time; (iii) the language in which the arbitration procedure shall be
>   carried out, shall be Spanish, and (iv) the parties waive any other resource
>   for the resolution of controversies.

FOURTEENTH.- ASSIGNMENTS.
None of the parties shall assign, gratuitously or onerously, in
any case, the execution or fulfillment of this contract, nor assign any of the
rights or obligations derived from the same.

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FIFTEENTH.- ENTIRE AGREEMENT. The present contract
includes all the stipulations agreed by the parties, and substitutes all
previous contracts and agreements, written or verbal, between MSX and FIREX
and/or the General Director. No previous contract, nor any negotiation between
the parties in the transaction of their businesses, or any representation of any
officer, employee, agent or representative of MSX and/or FIREX and/or the
General Director, made previous or after the signature of this contract, shall
be admitted in the interpretation of the terms and conditions of the same.

SIXTEENTH.- AMENDMENTS.Any
amendment to this contract shall be agreed in writing and signed by both
parties.

SEVENTEENTH.- LEGITIMACY OF THE CONTRACT. The parties
agree that in the present contract there is no error, deceitful representations,
bad faith, nor any other act or omission that affects their free will and that
could cause the nullity of the contract; therefore they ratify its content and
sign in two copies, one in English and the other in Spanish, agreeing that for
all effects of interpretation, the latter shall prevail, on the 25th
day of October, 2004, in the city of San Luis Potosi, S.L.P.

|By MSX                      | By FIREX                  
|--------------------------- | --------------------------
|                            |                           
|                            |                           
|/s/ Sergio Enrique Lopez B. | /s/ Jorge Mendizabal Acebo
|MR. SERGIO ENRIQUE LOPEZ B. | MR. JORGE MENDIZABAL ACEBO
|                           
|                           
|                           
|WITNESSES                  
|                            |                           
|                            |                           
|                            |                           
|/s/ Richard J. Hall         | /s/ Jesus Motilla Martinez
|MR. RICHARD J. HALL         | MR. JESUS MOTILLA MARTINEZ

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UNIQUE ATTACHMENT 
SPECIFICATIONS OF THE SERVICES

I.        
MAIN OBLIGATIONS OF THE GENERAL DIRECTOR.The parties
agree that he shall have, enunciatively and not limitedly, the following
responsibilities:

> a)
>   To execute the agreements and decisions of the Board of Directors.
>   b)
>   To prepare the program of activities and the annual budget of incomes and
>   expenses.
>   c)
>   To delegate and supervise issues of his competence, to his subordinates.
>   d)
>   To supervise the operation of the management of the areas corresponding to
>   him.
>   e)
>   To verify that an inventory of the goods under his care is made, as well as to
>   update it and control it permanently.

II.        
FACULTIES:The General Director shall be authorized
to:

> a)
>   Legally represent MSX through the granting that this makes, through its Board
>   of Directors, of powers of attorney, general and/or special, for acts of
>   administration, for lawsuits, acts of property, depending on the needs of MSX;
>   such powers of attorney shall be ratified before the attest of a Notary
>   Public.
>   b)
>   To represent MSX in the matters related to the operation of its areas and with
>   the personnel of the same.
>   c)
>   To appoint and dismiss technical and administrative personnel of MSX based on
>   legal and administrative laws, and which appointment isn't in charge of the
>   Board of Directors.
>   d)
>   To propose the Board of Directors, the appointment or dismissal of personnel
>   of trust.
>   e)
>   To supervise that the appointments are formally carried out, and formalized in
>   reliable documents, as well as to update them.

III.        
DOCUMENTATION IN CHARGE OF THE GENERAL DIRECTOR.Both
parties agree that he shall timely deliver the following documentation, during
the performance of his services, to the Board of Directors and/or to its
chairman:

> a)
>   Work schedule.
>   b)
>   Report of activities, progress of the services and financial statements
>   (monthly).
>   c)
>   Annual report for fiscal year.

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> d)
>   Brief description of medium - long term strategy plans, that fit the
>   strategies proposed and authorized by the Board of Directors.
>   e)
>   Annual operation plan of the current fiscal year (budget, goals, etc.) as well
>   as its monthly follow-up.
>   f)
>   Specific strategies of relevance.
>   g)
>   Brief description about the mechanism and periodicity of formal or informal
>   meetings, related to the activities of MSX.
>   h)
>   Brief description of the operation of committees, if it is the case.
>   i)
>   Policies and internal regulations.

IV.        
DOCUMENTATION IN CHARGE OF MSX.The parties agree
that, within the next thirty (30) days following the signature of this contract,
MSX shall provide the General Director, for a better performance of his
activities, the following information:

> a)
>   Accounting information (Financial statements of the last fiscal year, status
>   of the operation of the accounting system, etc.)
>   b)
>   Legal information (Public deeds, powers of attorney, effective contracts,
>   trials / lawsuits, documentation related to federal, state and local
>   authorities, etc.)
>   c)
>   Financial administration.
>   d)
>   Credit information.
>   e)
>   Fiscal status.
>   f)
>   Human resources (Classification of personnel, indicators of human factor,
>   union relationship, etc.)
>   g)
>   External advisors (Accountants, lawyers, industrial technicians, etc.)

|By MSX                      | By FIREX                  
|--------------------------- | --------------------------
|                            |                           
|                            |                           
|/s/ Sergio Enrique Lopez B. | /s/ Jorge Mendizabal Acebo
|MR. SERGIO ENRIQUE LÓPEZ B. | MR. JORGE MENDIZÁBAL ACEBO

This attachment forms part of the contract entered into by
and between the company "MINERA SAN XAVIER", S.A. de C.V., represented by Mr.
Sergio Enrique Lopez Briones an, by the company "FIREX", S.A. de C.V.,
represented by Mr. Jorge Mendizabal Acebo, dated October 25th, 2004.

This document is confidential and for the exclusive use of the parties of the
contract.

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