Metallica Resources Inc.: Exhibit 4.18 - Prepared by TNT Filings Inc.



 



Exhibit 4.18 

FIRST AMENDMENT TO MINING CONTRACT 


This FIRST AMENDMENT TO MINING CONTRACT, dated as of
April 5, 2005 (this "Amendment"), is entered into by and between Minera San
Xavier, S.A. de C.V., a Mexican corporation ("Owner"), and Washington Group
Latin America, Inc., a Delaware, U.S.A. corporation ("Contractor"). Owner and
Contractor are referred to in this Amendment individually as a "Party" and
together as the "Parties." 


RECITALS 


WHEREAS, Owner owns and operates the
Cerro San Pedro Mine located in Cerro de San Pedro, Mexico (the "Mine"); 


WHERAS, the Parties to this Amendment
are Parties to the Mining Contract, effective as of December 30, 2003 (the
"Mining Contract"), in which Owner engaged Contractor to, among other things,
perform drilling, blasting, excavating, mining, hauling and construction-related
services at the Mine; 

WHEREAS, in consideration for Owner
reimbursing Contractor for certain standby charges of Contractor during the time
period between May 12, 2004 and February 28, 2005, Contractor has agreed to the
development of a new termination provision in the event that the Owner must
terminate the Mining Contract due to an Event of Force Majeure; and 

WHEREAS, the Parties desire to enter
into this Amendment to formalize their verbal agreements and to update the
designation of persons to receive notice. 

NOW THEREFORE, in consideration of the
mutual promises set forth in this Amendment and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
Parties to this Amendment, intending to be legally bound, agree as follows:



AGREEMENT 



  1.
  Unless otherwise defined in this Amendment, all capitalized terms used herein
  that are defined in the Mining Contract shall have the respective meanings
  given to such terms in the Mining Contract. 

  
  2. The second sentence of the fourth
  paragraph of Article 13 shall be deleted in its entirety and the following
  sentences shall be substituted therefor: 



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  In the event of such termination,
  Owner shall pay Contractor the same amounts as would be paid, under Section
  12.2.1(a) through 12.2.1(e). Contractor shall also be entitled to a One
  Million Dollar ($1,000,000) break fee; 
  provided that,
  in the event Owner or any of Owner's direct or indirect affiliates recommences
  the Project within one year from the date in which Owner or Contractor
  terminates the Agreement due to an Event of Force Majeure, Contractor shall
  credit Owner $500,000 towards the remobilization of Contractor's Equipment and
  personnel to the Project. 

  3.
  In Article 14 of the
  Mining Contract 

  
    A.
    Change the recipient
    for primary copy of notice to Owner to the "General Manager" instead of the
    "Mine Manager"; 

    B.
    Change the recipient
    of the copy of any notice to Owner to "Richard J.  Hall, President and
    Chief Executive Office" instead of "Fred H. Lightner, Sr. Vice President and
    Chief Operating Officer"; 

    C.
    Add the following
    provision immediately following Contractor's official notice information:
    

  



	
    With a copy to:
	Washington Group
    International, Inc.
	
     
	Attn: Brian Best
	
     
	Regional Managing
    Attorney
	
     
	7800 E. Union
    Avenue, Suite 100
	
     
	Denver, CO 80237
	
     
	U.S.A.
	
     
	Phone: (303)
    843-2855
	
     
	Fax: (303)
    343-2266



  4.
  Exhibit K of the Mining Contract is deleted in its entirety and the
  revised Exhibit K
  attached hereto is substituted therefor. 

  5.
  Except as expressly
  modified pursuant to this Amendment, all other provisions of the Mining
  Contract are unaffected, remain in full force and effect with no other
  amendments or modifications and are ratified and confirmed in all respects.
  

  6.
  This Amendment shall
  be governed by the laws of the State of Colorado, excluding any provisions or
  principles thereof, which would require the application of the laws of a
  different jurisdiction. 

  7.
  This Amendment may be
  executed in any number of counterparts, all of which taken together shall
  constitute a single and complete agreement. 



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IN WITNESS WHEREOF and intending to be
legally bound, the Parties have executed this Amendment on this 5 day of April,
2005. 


	
    Minera San Xavier, S.A. de C.V.
	Washington Group
    Latin America,
	
     
	Inc.
	
     
	 
	
    By:        
    /s/ Richard J. Hall
	By:     
    /s/ LeRoy E. Wilkes
	
    Name:       
    Richard J. Hall
	Name:      
    LeRoy E. Wilkes
	
    Title:         
    Director
	Title:        
    President Mining Business Unit
	
     
	                 
    Washington Group International,
	
     
	                  
    Inc. Attorney-in-Fact
	
     
	                  
    Washington Group Latin America, Inc.


 

 


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EXHIBIT K 

PERMIT CONDITIONS 

(See Attached) 



 

 


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