Exhibit 4 July 28, 2000 Joint Filing Agreement We, the undersigned, hereby express our agreement that the attached Schedule 13D is, and any future amendments thereto may be, filed on behalf of each of us. BNP PARIBAS By: /s/ M.S. Alexander...

     The fourth exhibit is replaced with the following:

                                                                       Exhibit 4
                                                                   July 28, 2000
                             Joint Filing Agreement

     We,  the  undersigned,  hereby  express  our  agreement  that the  attached
Schedule  13D is, and any future  amendments  thereto may be, filed on behalf of
each of us.



BNP PARIBAS



By:  /s/ X.X. Xxxxxxxxx
   ------------------------
      Name: X.X. Xxxxxxxxx
      Title: Managing Director



PARIBAS NORTH AMERICA, INC.



By:  /s/ Xxxxx Xxxxxxx
   ------------------------
      Name: Xxxxx Xxxxxxx
      Title: Chief Financial Officer



PARIBAS PRINCIPAL, INCORPORATED



By: /s/   X. X. Xxxxxxxxx
   ------------------------
   Name:  X. X. Xxxxxxxxx
   Title:  President


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