EXHIBIT 10(iiii)


                                      169
<PAGE>

                            ------------------------

                               TIREX AMERICA INC.

                            ------------------------

                                 AMENDMENT NO. 2

                             TO EXECUTIVE AGREEMENT

                   OF JANUARY 18, 1995 AS AMENDED MAY 30, 1996

                            ------------------------

         Second Amendment, made this 1st day of May 1997, by and between


                               Tirex America Inc.
                               3767 Thimens
                               Ville St. Laurent
                               Quebec, Canada H4R 1W4

                                Tirex Canada Inc.
                                3767 Thimens
                                Ville St. Laurent
                                Quebec, Canada H4R 1W4

                                              (collectively, the "Corporation"*)

                                       and


                                Terence C. Byrne
                                489 Grosvner Street
                                Westmount, Quebec
                                H3Y 2S5
                                              (the "Executive").

the parties to a certain executive  agreement,  dated as of January 18, 1995 and
amended  as of May 30,  1996 (the  "Executive  Agreement").  Terms  used in this
Amendment  which are defined in the Executive  Agreement and not defined  herein
shall have the same meaning herein as therein.


                                      170
<PAGE>

         Whereas,  the Executive is employed by the Corporation as its President
and  Treasurer,  serving  in such  positions  as its  Chief  Executive  Officer,
pursuant to the provisions of the said Executive agreement, the term of which is
scheduled to expire on January 17, 1998;

         Whereas, The Executive has since the Commencement Date performed all of
his duties and met all of his responsibilities  under the terms of the Executive
Agreement in a superlative  manner and the board of directors of the Corporation
has determined that it will be in the best interests of the Corporation, and the
Executive has agreed, to extend the term of the Executive  Agreement to December
31, 2003;

                  Now  therefore,  in  consideration  of the premises and of the
mutual promises and covenants  hereinafter set forth, the parties agree to amend
the Executive Agreement, as follows:

A.  AMENDMENTS

         Section 4 of the Executive Agreement is hereby amended so as to read as
follows:

         4. Term of Employment

                  The term of  employment  of the  Executive by the  Corporation
         shall be  extended  beyond the Initial  Term of three (3) years,  which
         began on the Effective Date and, unless terminated  earlier pursuant to
         Section 6, shall  continue  until  December 31, 2003. At any time prior
         December 31, 2003,  the  Corporation  and the  Executive  may by mutual
         written agreement  further extend the Executive's  employment under the
         terms of this  Agreement  for such  additional  periods  as they  shall
         mutually agree.

B.  NO OTHER AMENDMENTS

         Except as expressly  provided in this  Amendment,  all of the terms and
conditions of the Executive Agreement remain in full force and effect.

C.  COUNTERPARTS

         This  Amendment  may be executed in any number of  counterparts  and by
each  party on a  separate  counterpart,  each of  which  when so  executed  and
delivered shall be an original,  but all of which together shall  constitute one
Amendment.


                                      171
<PAGE>

         In Witness Whereof, the parties hereto have caused this Amendment to be
executed the day and year first above written.


                                          TIREX AMERICA INC.          


                                          By /s/ Louis V. Muro                  
                                            ------------------------------------
                                             Louis V. Muro, Vice President of
                                               Engineering and Member of the
                                               Executive Committee of the Board
                                               of Directors.
                                  
                                  
                                          TIREX AMERICA INC.
                                
                                  
                                          By /s/ John G. Hartley
                                            ------------------------------------
                                             John G. Hartley,  Member of the
                                               Executive Committee of the Board
                                               of Directors
                                  
                                  
                                          TIREX CANADA INC.
                                  
                                  
                                          By /s/ Louis V. Muro
                                            ------------------------------------
                                             Louis V. Muro, Vice President
                                  
                                  
                                  
                                          EXECUTIVE
                                  
                                  
                                           /s/ Terence C. Byrne
                                          --------------------------------------
                                          Terence C. Byrne


                                      172