Exhibit 10.83

                                COMPOSITECH LTD.
                               710 Koehler Avenue
                           Ronkonkoma, New York 11779


                                  July 21, 2000


Sovereign Capital Advisors, LLC
3340 Peachtree Road, NE, Suite 2320
Atlanta, Georgia  30326
Facsimile:
Attention:  Mr. Paul D. Hamm

Dear Sirs:

     Reference  is made to the  Series  1  Bridge  Note  Purchase  and  Security
Agreement,  dated  March  16,  1999,  by and  among  Compositech  Ltd.  and  the
Purchasers  listed therein (the "Note Purchase  Agreement"),  as amended by that
certain  First  Amendment  to the Series 1 Bridge  Note  Purchase  and  Security
Agreement,  dated  April  21,  1999 and  executed  by the  Company  and  certain
Purchasers in connection with the Second Closing (the "First  Amendment"),  that
certain  Second  Amendment  to the Series 1 Bridge Note  Purchase  and  Security
Agreement,  dated  July 28,  1999,  and  executed  by the  Company  and  certain
Purchasers in connection with the Third Closing (the "Second  Amendment"),  that
certain Letter  Agreement,  dated November 22, 1999, and executed by the Company
and the  Purchasers  (the  "November  Letter  Agreement"),  that certain  Letter
Agreement  dated April 21, 2000,  and executed by the Company and the Purchasers
(the "April Letter Agreement"), and that certain Letter Agreement, dated July 7,
2000,  and  executed  by the  Company  and  SovCap  Equity  Partners,  Ltd.,  as
Representative  for the Purchasers (the "July Letter  Agreement",  together with
the Note Purchase  Agreement,  the First Amendment,  the Second  Amendment,  the
November  Letter  Agreement  and  the  April  Letter  Agreement,  the  "Purchase
Agreement").  Defined  terms,  used but not defined  herein,  have the  meanings
ascribed thereto in the Purchase Agreement.

     The parties hereto agree that the Secured Convertible Bridge Financing Note
of  Compositech  Ltd. in the amount of  $98,327.00  issued to Sovereign  Capital
Advisors,  LLC (the  "Placement  Agent")  on  October  4, 1999 to  evidence  the
placement fee owed to the  Placement  Agent as part of the  cancellation  of the
original  Bridge  Notes and issuance of  replacement  Bridge Notes on October 4,
1999 (the  "Placement  Note") be amended by striking the date "July 21, 2000" in
the seventh line of the Placement  Note and  inserting  into the seventh line in
place of such date "September 25, 2000" so that the defined term "Maturity Date"
is redefined and definitively established as September 25, 2000.


<PAGE>


     The  provisions of the  Placement  Note for interest at the Note Rate up to
the Maturity  Date,  as now defined in this  Agreement,  and for interest at the
Default Rate thereafter, shall remain in full force and effect.

     This  Agreement  supersedes  all other  prior  oral or  written  agreements
between the Company and the Placement Agent and their respective  affiliates and
person acting on their behalf with respect to the matters specifically  referred
to herein, and this Agreement and the instruments  referenced herein contain the
entire  understanding  of the parties with respect to the matters covered herein
and therein and, except as specifically set forth herein or therein, neither the
Company nor the Placement Agent make any representation,  warranty,  covenant or
undertaking  with  respect to such  matters  other than those  contained  in the
Placement Note or the Placement Agency  Agreement,  dated March 16, 1999, by and
between the Company and the Placement Agent (the "Placement  Agency  Agreement")
which  remain  in full  force  and  effect  as if made on the  date  hereof.  No
provision of this Agreement may be waived or amended other than by an instrument
in writing signed by the party to be charged with enforcement

     All  notices  and other  communications  hereunder  shall be in writing and
shall be  delivered  as  provided  for in the  Placement  Agency  Agreement,  as
follows:

                             If to the Placement Agent to:

                                     Sovereign Capital Advisors, LLC
                                     3340 Peachtree Road, N.E.
                                     Suite 2320
                                     Atlanta, Georgia  30326
                                     Attention:  Don Odom
                                     Tel:  (404) 814-3737
                                     Fax:  (404) 812-3738

                             With a copy to:

                                     Balboni Law Group, LLC
                                     3475 Lenox Road
                                     Suite 990
                                     Atlanta, Georgia  30326
                                     Attention:  Geraldo M. Balboni II, Esq.
                                     Tel:  (404) 812-3100
                                     Fax:  (404) 812-3101

                             If to the Company to:


                                     Compositech Ltd.
                                     710 Koehler Avenue
                                     Ronkonkoma, New York 11779
                                     Attention:  Samuel S. Gross
                                     Fax:     (631) 585-7710

                             With a copy to:

                                     Patterson, Belknap, Webb & Tyler LLP
                                     1133 Avenue of the Americas
                                     New York, New York  10036
                                     Attention:  Edward F. Cox
                                     Facsimile:  (212) 336-2222


<PAGE>


     This  Agreement  shall be  governed  by the  laws of the  State of New York
without regard to the conflicts of law doctrine of such state.

     This  Agreement  may be  executed  in  counterparts,  each of  which  shall
constitute an integral original part of one and the same original instrument.

     If the foregoing  correctly sets forth the  understanding  among us, please
indicate your agreement and acceptance by signing below.

                                     Sincerely,



                                     COMPOSITECH LTD.


                               By:   _______________________________
                                     Samuel Gross
                                     Executive Vice President

Acknowledged, agreed and accepted by the undersigned:

SOVEREIGN CAPITAL ADVISORS, LLC


By:  ___________________________________
     Authorized Signatory