<PAGE>   1
                                                                      EXHIBIT 21

                                  SUBSIDIARIES

(Companies in which FINA, Inc. owns 50% or more at 12-31-95)
<TABLE>
<CAPTION>
                                                        State of
Name of Subsidiary                                      Incorporation
------------------                                      -------------
<S>                                                     <C>           <C>
American Petrofina Pipe Line Company                    Delaware      100%
                                                                      
American Petrofina, Incorporated                        Delaware      100%
 (nameholder, incorporated 6-10-91)                                   
                                                                      
Acturus Shipping, Inc.                                  Delaware      100%
                                                                      
Archon Shipping, Inc.                                   Delaware      100%
                                                                      
Cosden, Inc.                                            Louisiana     100%
                                                                      
Cos-Mar, Incorporated                                   Louisiana      50%
                                                                      
Cos-Mar Company                                      (Joint Venture)   50%
                                                                      
Fina LaTerre, Inc.                                      Delaware      100%
                                                                      
Fina Natural Gas Company                                Delaware      100%
                                                                      
Fina Oil and Chemical Company                           Delaware      100%
                                                                      
Fina Pipe Line Company                                  Texas         100%
(formerly Cosden Pipe Line Company)                                   
                                                                      
Fina Sales Corporation                                  Barbados      100%
                                                                      
Fina Security, Inc.                                     Delaware      100%
(formerly American Protectorate, Inc.)                                
                                                                      
Fina Splitter, Inc.                                     Delaware      100%
                                                                      
Fina Technology, Inc.                                   Delaware      100%
                                                                      
Fina United Corporation                                 Delaware      100%
                                                                      
Finachem Sales Corporation                              Barbados       50%
                                                                      
Finachem, U. S.                                      (Partnership)     50%
                                                                      
FinaServe, Inc.                                         Texas         100%
                                                                      
Fin-Tex Pipe Line Company                               Texas         100%
                                                                      
La Terre Development Corp.                              Delaware      100%
                                                                      
Mistal, Inc.                                            Delaware       53%
                                                                      
Petrofina Gas Pipeline Company                          Delaware      100%
                                                                      
Petrofina - U. S. Incorporated                          Delaware      100%
                                                                      
Sigma Coatings, Inc.                                    Delaware      100%
</TABLE>