Exhibit 4.6

                                 THIRD AMENDMENT
                                       to
                                RIGHTS AGREEMENT


     THIRD AMENDMENT dated as of September 10, 1999 ("this  Amendment")  between
Tyco International Ltd., a Bermuda company limited by shares (the "Company") and
Citibank,  N.A., New York branch, a national banking association organized under
the laws of the  United  States of  America  acting  solely  through  its branch
located at 111 Wall Street, New York, NY 10043 (the "Rights Agent").

     WHEREAS,  the  above-mentioned  parties have  previously  entered into that
certain  Rights  Agreement  dated  as of  November  6,  1996,  as  amended  (the
"Agreement");

     WHEREAS,  such parties wish to amend the  Agreement in the manner set forth
below.

     NOW, THEREFORE, the parties hereto agree as follows:

     1. All  capitalized  terms used herein,  unless  otherwise  defined herein,
shall have the meanings given them in the  Agreement,  and each reference in the
Agreement to "this Agreement",  "hereof", "herein",  "hereunder" or "hereby" and
each  other  similar  reference  shall be  deemed to refer to the  Agreement  as
amended hereby.  All references to the Agreement in any other agreement  between
or among any of the parties hereto relating to the transactions  contemplated by
the Agreement shall be deemed to refer to the Agreement as amended hereby.

     2. The  definition  of  "Final  Expiration  Date" in  Section  1 is  hereby
replaced in its entirety with the following:

        "Final  Expiration  Date" means the close of business on  September  30,
1999.

     3. This Amendment shall be governed by and construed in accordance with the
laws of Bermuda.

     4. This  Amendment  may be signed in any  number of  counterparts,  each of
which shall be deemed an  original,  with the same  effect as if the  signatures
thereto and hereto were upon the same instrument.

     5. Except as expressly  amended hereby,  the Agreement shall remain in full
force and effect.



     IN WITNESS WHEREOF,  this Amendment has been duly executed as a deed by the
respective  authorized  officers of the parties  hereto,  in each case as of the
date and year first above written.


                                              TYCO INTERNATIONAL LTD.


                                              By:  /s/ Mark H. Swartz
                                                 --------------------------
                                              Name:  Mark H. Swartz
                                              Title: Executive Vice President &
                                                     Chief Financial Officer



                                              CITIBANK, N.A.


                                              By: /s/ Emi Mak
                                                 ------------------
                                              Name:  Emi Mak
                                              Title: Vice President

                                              111 Wall Street
                                              New York, NY 10043