EXHIBIT 10.62

                     AMENDMENT NO. 3 TO CREDIT AGREEMENT.


     AMENDMENT dated as of December 31, 1998 among ULTRAMAR DIAMOND
SHAMROCK CORPORATION, CANADIAN ULTRAMAR COMPANY (the "Borrower"), the
LENDERS listed on the signature pages hereof (the "Lenders") and CANADIAN
IMPERIAL BANK OF COMMERCE, as Agent (the "Agent").


PREAMBLE:

1.        The parties hereto entered into a Credit Agreement dated December 19,
     1996 (the "Agreement"), as amended in February, 1997 and on November
     7,1997; and

2.        The parties hereto desire to amend certain provisions of the Agreement
     in the manner set forth below.

AGREEMENT:

     For good an valuable consideration, the parties hereto agree as follows:

1.1  Definition. References. Unless otherwise specifically defined herein, each
     ----------------------                                                    
     term used herein which is defined in the Agreement shall have the meaning
     given such term in the Agreement. Each reference to "hereof", "hereunder",
     "herein" and "hereby" and each other similar reference and each reference
     to "this Agreement" and each other similar reference contained in the
     Agreement shall from and after the date hereof refer to the Agreement as
     amended hereby.

2.1  Amendment to Section 1.1 of the Agreement. The definition of "Consolidated
     ------------------------------------------                                 
     Net Income" in Section 1.1 of the Agreement is replaced with the
     following:

          "Consolidated Net Income" means, for any period, the net income (or
          loss) of the Borrower or UDSC, as the case may be, and its
          Consolidated Subsidiaries for such period; provided that there shall
          be excluded from such calculation (i) any after-tax gains or losses
          attributable to asset sales (other than sales in the ordinary course
          of business) or returned surplus assets of any Plan, (ii) in the case
          of UDSC only, up to U.S. $127,800,000 of non-recurring charges in
          connection with or as a result of (A) the Merger or (B) certain
          changes to conform the accounting practices of Ultramar Corporation
          and Diamond Shamrock, Inc., (iii) (A) U.S. $131,600,000 in non-
          recurring restructuring charges in connection with certain corporate
          restructuring activities initiated in 1998, as reflected by UDSC's
          report on Form 10-Q/A for the quarterly period ended June 30, 1998,
          and (B) up to U.S. $135,000,000 of non-recurring non-cash charges
          against income taken in connection with the adjustment of inventory
          value for the fiscal year ended


                                      -2-
 
          December 31, 1998, and (iv) to the extent not included in clauses (i),
          (ii) or (iii), any net extraordinary gains or net extraordinary
          losses.

3.1  Governing Law. This Amendment shall be governed by and construed in
     -------------                                                      
     accordance with the laws of the Province of Ontario, Canada.

4.1  Counterparts; Effectiveness. This Amendment may be signed in any number of
     ---------------------------                                               
     counterparts, each of which shall be an original, with the same effect as
     if the signatures thereto and hereto were upon the same instrument. This
     Amendment shall become effective as of the date hereof when the Agent shall
     have received duly executed counterparts hereof signed by the Borrower and
     the Majority Lenders (or, in the case of any party as to which an executed
     counterpart shall not have been received, the Agent shall have received
     telegraphic, telex or other written confirmation from such party of
     execution of a counterpart hereof by such party).

     The parties hereto have caused this Amendment to be executed by their
respective authorized representatives or officers effective the date referred to
above.


                       CANADIAN ULTRAMAR COMPANY                          
                                                                          
                                                                          
                       By: /s/ Steve Blank                                
                          --------------------------------                
                       Name: Steve Blank                                  
                       Title: Treasurer                                   
                       Address: c/o Ultramar Diamond Shamrock Corporation 
                       Facsimile: (210) 592- 2010                         
                                                                          
                                                                          
                       ULTRAMAR DIAMOND SHAMROCK                          
                       CORPORATION                                        
                                                                          
                                                                          
                       By: /s/ Steve Blank                                
                          --------------------------------                
                       Name: Steven A. Blank                              
                       Title: Vice President and Treasurer                
                       Address: 6000 N Loop 1604 W                        
                       San Antonio, Texas 78249                           
                       Facsimile: (210) 592-2010                           


                                      -3-
 
                    LENDERS SIGNATURES                             
                                                                   
                    CANADIAN IMPERIAL BANK OF COMMERCE, AS AGENT   
                                                                   
                                                                   
                    By:    /s/ Tim Thomas                        
                       --------------------------------            
                    Name:      Tim Thomas                          
                    Title:     Executive Director                  
                    Address:   Commerce Court West, 7th Flr.,      
                               Toronto, Ontario M5L 1A2            
                    Facsimile: (416) 980-2804                      
                                                                   
                                                                   
                                                                   
                    By:    /s/ D. Evelyn                         
                       -------------------------------             
                    Name:      D. Evelyn                           
                    Title:     Director                            
                    Address:   Commerce Court West, 7th Flr.,      
                               Toronto, Ontario M5L 1A2            
                    Facsimile: (416) 980-2804                      
                                                                   
                                                                   
                    CANADIAN IMPERIAL BANK OF COMMERCE             
                                                                   
                                                                   
                                                                   
                    By:_______________________________             
                    Name:                                          
                    Title:                                         
                    Address:   10th FIr., 855 - 2nd Street, S.W.   
                               Calgary, Alberta T2P 2P2            
                    Facsimile: (403) 221-5779                      
                                                                   
                                                                   
                    By:_______________________________             
                    Name:                                          
                    Title:                                         
                    Address:   10th Flr., 855 - 2nd Street, S.W.   
                               Calgary, Alberta T2P 2P2            
                    Facsimile: (403) 221-5779                       


                                      -3-
 
                    LENDERS SIGNATURES                             
                                                                   
                    CANADIAN IMPERIAL BANK OF COMMERCE, AS AGENT   
                                                                   
                                                                   
                    By:_______________________________             
                    Name:                                          
                    Title:                                         
                    Address:    Commerce Court West, 7th Flr.,     
                                Toronto, Ontario M5L 1A2           
                    Facsimile:  (416) 980-2804                      
                                                                   
                                                                   
                    By:_______________________________             
                    Name:                                          
                    Title:                                         
                    Address:    Commerce Court West, 7th Flr.,     
                                Toronto, Ontario M5L 1AS           
                    Facsimile:  (416) 980-2804                      
                                                                   
                                                                   
                    CANADIAN IMPERIAL BANK OF COMMERCE             
                                                                   
                                                                   
                                                                   
                    By:     /s/ D. J. Swain                    
                       --------------------------------            
                    Name:       D. J. Swain                        
                    Title:      Vice President                     
                    Address:    10th Flr., 855 - 2nd Street, S.W.  
                                Calgary, Alberta T2P 2P2           
                    Facsimile:  (403) 221-5779                     
                                                                   
                                                                   
                                                                   
                    By:     /s/ L. Sagriff                     
                       -------------------------------             
                    Name:       L. Sagriff                      
                    Title:      Executive Director                 
                    Address:    10th Flr., 855 - 2nd Street, S.W.  
                                Calgary, Alberta T2P 2P2           
                    Facsimile:  (403) 221-5779                      


                                      -4-
 
                    BANK OF TOKYO - MITSUBISHI (CANADA)                      
                                                                             
                                                                             
                    By:    /s/ Amos Simpson                                  
                       -------------------------------                       
                    Name:      Amos Simpson                                  
                    Title:     General Manager                               
                    Address:   600 rue de la Gauchetiere Ouest, Suite 2780,  
                               Montreal, Quebec H3B 4L8                      
                    Facsimile: (514) 875-9392                                
                                                                             
                                                                             
                    FUJI BANK CANADA                                         
                                                                             
                                                                             
                    By:_______________________________                       
                    Name:                                                    
                    Title:                                                   
                    Address:                                                 
                    Facsimile:                                               
                                                                             
                                                                             
                    THE BANK OF NOVA SCOTIA                                  
                                                                             
                                                                             
                                                                             
                    By:________________________________                      
                                                                             
                    Name:       David Torrey                                 
                    Title:      Relationship Manager                         
                    Address:    44 King Street West,                         
                                Toronto, Ontario MAH 1H1                   
                    Facsimile:  (416) 866-2009                               
                                                                             
                                                                             
                    By:_______________________________                       
                    Name:                                                    
                    Title:                                                   
                    Address:    44 King Street West,                         
                                Toronto, Ontario MAH 1H1                     
                    Facsimile:  (416) 866-2009                                


                                      -4-
 
                    BANK OF TOKYO - MITSUBISHI (CANADA)                    
                                                                           
                                                                           
                    By:_______________________________                     
                                                                           
                    Name:      Amos Simpson                                 
                    Title:     General Manager                              
                    Address:   600 rue de la Gauchetiere Ouest, Suite 2780, 
                               Montreal, Quebec H3B 4L8                    
                    Facsimile: (514) 875-9392                              
                                                                           
                                                                           
                    FUJI BANK CANADA                                       
                                                                           
                                                                           
                    By:/s/ Daniel Lee                                      
                       -------------------------------                     
                    Name:  Daniel Lee                                      
                    Title: Senior Vice President
                    Address:                                               
                    Facsimile:                                             
                                                                           
                                                                           
                    THE BANK OF NOVA SCOTIA                                
                                                                           
                                                                           
                                                                           
                    By:_______________________________                     
                                                                            
                    Name:       David Torrey                                
                    Title:      Relationship Manager                        
                    Address:    44 King Street West,                        
                                Toronto, Ontario MAH 1H1                  
                    Facsimile:  (416) 866-2009                              
                                                                           
                                                                           
                    By:________________________________                    
                    Name:                                                  
                    Title:                                                 
                    Address:    44 King Street West,                        
                                Toronto, Ontario MAH 1H1                   
                    Facsimile:  (416) 866-2009                              


                                      -4-
 
                    BANK OF TOKYO - MITSUBISHI (CANADA)                    
                                                                           
                                                                           
                    By:_______________________________                     
                    Name:      Amos Simpson                                 
                    Title:     General Manager                              
                    Address:   600 rue de la Gauchetiere Ouest, Suite 2780, 
                               Montreal, Quebec H3B 4L8                    
                    Facsimile: (514) 875-9392                              
                                                                           
                                                                           
                    FUJI BANK CANADA                                       
                                                                           
                                                                           
                    By:_______________________________                     
                    Name:                                                  
                    Title:                                                 
                    Address:                                               
                    Facsimile:                                             
                                                                           
                                                                           
                    THE BANK OF NOVA SCOTIA                                
                                                                           
                                                                           
                    By:     /s/ David Torrey                                    
                       -------------------------------                     
                    Name:       David Torrey                                
                    Title:      Relationship Manager                        
                    Address:    44 King Street West,                        
                                Toronto, Ontario MAH 1H1                  
                    Facsimile:  (416) 866-2009                              
                                                                           
                                                                           
                    By:     /s/ Stephanie Spencer                               
                       -------------------------------                     
                    Name:       Stephanie Spencer                          
                    Title:      Account Officer                            
                    Address:    44 King Street West,                        
                                Toronto, Ontario MAH 1H1                   
                    Facsimile:  (416) 866-2009                              
                                     


                                      -5-
 
                    ABN AMRO BANK CANADA                         
                                                                 
                                                                 
                    By:/s/ [SIGNATURE ILLEGIBLE]^^               
                       --------------------------------          
                    Name:       [ILLEGIBLE]^^                                 
                    Title:      SENIOR VICE PRESIDENT            
                    Address:    #1500, 600 de Maisonneuve Ouest  
                                Montreal, Quebec H3A 3J2         
                    Facsimile:  (514) 284-2357                   
                                                                 
                                                                 
                                                                 
                    CAISSE CENTRALE DESJARDINS                   
                                                                 
                                                                 
                    By:_______________________________           
                    Name:       Robert LaBelle                   
                    Title:      Director, Corporate Banking      
                    Address:    1 Complex Desjardins, Suite 2822 
                                Montreal, Quebec H5B 1B3         
                    Facsimile:  (514) 288-9683                   
                                                                 
                                                                 
                                                                 
                                                                 
                    CREDIT LYONNAIS CANADA                       
                                                                 
                    By:________________________________          
                    Name:       Joycelyn Cote                    
                    Title:      Vice President                   
                    Address:    2000 Mansfield, 16th Floor       
                                Montreal, Quebec H3A 3A6             
                    Facsimile:  (514) 284-2357                   
                                                                 
                                                                 
                    By:_______________________________           
                    Name:       Cynthia Hansen                   
                    Title:      Assistant Vice President         
                    Address:    2000 Mansfield, 16th Floor       
                                Montreal, Quebec H3A 3A6         
                    Facsimile:  (514) 288-9683                    
                                      


                                      -5-
 
                ABN AMRO BANK CANADA                          
                                                             
                                                             
                By:_______________________________           
                Name:       Enrico Pallatto                  
                Title:                                       
                Address:    #1500, 600 de Maisonneuve Ouest  
                            Montreal, Quebec H3A 3J2         
                Facsimilie  (514) 284-2357                   
                                                             
                                                             
                                                             
                CASSIE CENTRALE DESJARDINS                   
                                                             
                                                             
                By:     /s/ Robert LaBelle                        
                   -------------------------------           
                Name:       Robert LaBelle                   
                Title:      Director, Corporate Banking      
                Address:    1 Complexe Desjardins, Suite 2822
                            Montreal, Quebec H5B 1B3         
                Facsimile:  (514) 284-2357                   
                                                             
                                                             
                                                             
                CREDIT LYONNAIS CANADA                       
                                                             
                By:________________________________          
                Name:       Jocelyn Cote                     
                Title:      Vice President                   
                Address:    2000 Mansfield, 16th Floor       
                            Montreal, Quebec H3A 3A6         
                Facsimile:  (514) 288-9683                   
                                                             
                                                             
                                                             
                By:________________________________          
                Name:       Cynthia Hansen                   
                Title:      Assistant Vice President         
                Address:    2000 Mansfield, 16th Floor       
                            Montreal, Quebec H3A 3A6         
                Facsimile:  (514) 288-9683                    

 
                                                      


                                      -5-
 
                     ABN AMRO BANK CANADA                          
                                                                  
                                                                  
                     By:________________________________          
                     Name:       Enrico Pallatto                  
                     Title:                                       
                     Address:    #1500, 600 de Maisonneuve Ouest  
                                 Montreal, Quebec H3A 3J2         
                     Facsimilie  (514) 284-2357                   
                                                                  
                                                                  
                                                                  
                     CASSIE CENTRALE DESJARDINS                   
                                                                  
                                                                  
                     By:________________________________          
                     Name:       Robert LaBelle                   
                     Title:      Director, Corporate Banking      
                     Address:    1 Complexe Desjardins, Suite 2822
                                 Montreal, Quebec H5B 1B3         
                     Facsimile:  (514) 284-2357                   
                                                                  
                                                                  
                                                                  
                     CREDIT LYONNAIS CANADA                       
                                                                  
                     By:     /s/ Jocelyn Cote                          
                        --------------------------------          
                     Name:       Jocelyn Cote                     
                     Title:      Vice President                   
                     Address:    2000 Mansfield, 16th Floor       
                                 Montreal, Quebec H3A 3A6         
                     Facsimile:  (514) 288-9683                   
                                                                  
                                                                  
                                                                  
                     By:     /s/ Cynthia Hansen                        
                        --------------------------------          
                     Name:       Cynthia Hansen                   
                     Title:      Assistant Vice President         
                     Address:    2000 Mansfield, 16th Floor       
                                 Montreal, Quebec H3A 3A6         
                     Facsimile:  (514) 288-9683                    


                                      -6-
 
                    THE INDUSTRIAL BANK OF JAPAN (CANADA)               
                                                                        
                                                                        
                    By:     /s/ Campbell McLeish                             
                    ----------------------------------                  
                    Name:       Campbell McLeish                        
                    Title:      Senior Vice President                   
                    Address:    100 Yonge Street, Suite 1102            
                                Toronto, Ontario M5C 2W1                 
                    Facsimile:  (416) 367-3452                          
                                                                        
                                                                        
                                                                        
                    ROYAL BANK OF CANADA                                
                                                                        
                    By:________________________________                 
                    Name:       Fiona Dubsky                            
                    Title:      Senior Manager                           
                    Address:    1 Place Ville Marie, 8th Floor West Wing
                                Montreal, Quebec H3C 3A9                
                    Facsimile:  (514) 874-5315                          
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        

 
                                      -6-
 
                    THE INDUSTRIAL BANK OF JAPAN (CANADA)               
                                                                        
                                                                        
                                                                        
                    By:________________________________                 
                    Name:       Campbell McLeish                        
                    Title:      Senior Vice President                   
                    Address:    100 Yonge Street, Suite 1102            
                                Toronto, Ontario M5C 2W1                
                    Facsimile:  (416) 367-3452                          
                                                                        
                                                                        
                    ROYAL BANK OF CANADA                                
                                                                        
                                                                        
                                                                        
                    By:     /s/ Fiona Dubsky                                  
                       -------------------------------                  
                    Name:       Fiona Dubsky                        
                    Title:      Senior Manager                          
                    Address:    1 Place Ville Marie, 8th Floor West Wing 
                                Montreal, Quebec H3C 3A9                
                                                                        
                    Facsimile:  (514) 874-5315