<PAGE>

                               FIRST AMENDMENT TO
                               PURCHASE AGREEMENT


         FIRST AMENDMENT TO PURCHASE AGREEMENT (this "AMENDMENT") dated as of
July 2, 2000, between THOMAS & BETTS CORPORATION, a Tennessee corporation
("SELLER"), and TYCO GROUP S.A.R.L., a Luxembourg corporation ("Buyer").

                              W I T N E S S E T H:

         WHEREAS, Buyer and Seller have entered into a Purchase Agreement, dated
as of May 7, 2000 (the "PURCHASE AGREEMENT"); and

         WHEREAS, the parties hereto wish to amend the Purchase Agreement and to
amend the Disclosure Schedules relating to the Purchase Agreement as set forth
below.

         NOW, THEREFORE, IT IS AGREED:

         1.       AMENDMENTS. The Purchase Agreement is hereby amended as
         follows:

                  (a) Section 1.01 of the Purchase Agreement is hereby amended
         by inserting the following directly after the definition of "Foreign
         Acquired Subsidiaries":

                           ""HOLDBACK AMOUNT" shall mean $50,000,000."

                  (b) Section 2.07 of the Purchase Agreement is hereby amended
         by deleting Section 2.07(a)(i) in its entirety and inserting in lieu
         thereof the following:

                                    "(i) Buyer shall deliver $750,000,000, less
                           (1) any third-party indebtedness for borrowed money
                           and any pre-payment penalties relating thereto of any
                           Acquired Subsidiary outstanding as of the Closing
                           Date, less (2) the Holdback Amount. Buyer shall
                           deliver such amount in immediately available funds by
                           wire transfer to an account or accounts designated by
                           Seller, by notice to Buyer, not later than two
                           business days prior to the Closing Date."


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                  (c) Section 2.09 of the Purchase Agreement is hereby amended
         by deleting Section 2.09(c) in its entirety and inserting in lieu
         thereof the following:

                           "Any payment pursuant to Section 2.09(a) or 2.09(b)
                           shall be made in accordance with the provisions of
                           Section 2.10(c) hereof and at a mutually convenient
                           time and place within 10 days after Final Working
                           Capital and Final Long-Term Tangible Assets have been
                           determined pursuant to this Section 2.09 (the date of
                           such payment, the "FINAL SETTLEMENT DATE"). The
                           amount of any payment to be made pursuant to this
                           Section 2.09 shall bear interest from and including
                           the Closing Date to but excluding the date of payment
                           at a rate per annum equal to 6.5% (the "CALCULATION
                           RATE"). Such interest shall be payable at the same
                           time as the payment to which it relates and shall be
                           calculated daily on the basis of a year of 365 days
                           and the actual number of days elapsed (the
                           "CALCULATION METHOD"). The aggregate payment required
                           to be made under this Section 2.09(c), if any, is
                           referred to as the "PURCHASE PRICE ADJUSTMENT
                           Payment"."

                  (d) Article 2 of the Purchase Agreement is hereby amended by
         inserting the following section immediately following the final
         sentence of Section 2.09:

                           2.10.  SUBSEQUENT CLOSINGS; SETTLEMENT OF HOLDBACK
                           AND PURCHASE PRICE ADJUSTMENT. (a) [Intentionally
                           deleted]

                           (b) At the Subsequent Closing relating to Thomas &
                           Betts Hungary Kft. (the "HUNGARY CLOSING"), Buyer
                           shall pay to Seller in immediately available funds,
                           by wire transfer to an account designated by Seller,
                           an amount equal to $15,000,000 (the "HUNGARY PURCHASE
                           PRICE PAYMENT") plus interest on such amount from and
                           including the Closing Date to but excluding the date
                           of payment at the Calculation Rate and based on the
                           Calculation Method. At the Subsequent Closing
                           relating to Thomas & Betts Monterrey, Thomas & Betts
                           Hermosillo and Thomas & Betts de Mexico (the "MEXICO
                           CLOSING"), Buyer shall pay to Seller in immediately
                           available funds, by wire transfer to an account
                           designated by Seller, an amount equal to $735,000
                           (the "MEXICO PURCHASE PRICE PAYMENT") plus


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                           interest on such amount from and including the
                           Closing Date to but excluding the date of payment at
                           the Calculation Rate and based on the Calculation
                           Method. Notwithstanding the foregoing, (i) if the
                           Hungary Closing occurs after the Mexico Closing, then
                           the Hungary Purchase Price Payment shall be reduced
                           by $735,000, (ii) if the Mexico Closing occurs after
                           the Hungary Closing, then the Mexico Purchase Price
                           Payment shall be reduced by $735,000, and (iii) if
                           the Mexico Closing and the Hungary Closing occur
                           simultaneously, then the aggregate of the Mexico
                           Purchase Price Payment and the Hungary Purchase Price
                           Payment shall not exceed $15,000,000; PROVIDED, that
                           in no case shall such reduction affect the purchase
                           price allocation as agreed between the parties.

                           (c) In the event that a payment is required to be
                           made by Seller to Buyer pursuant to Section 2.09(c)
                           hereof:

                           (i) if (x) the Purchase Price Adjustment Payment
                           exceeds (y) the sum of $35,000,000 plus interest on
                           such amount from and including the Closing Date to
                           but excluding the Final Settlement Date at the
                           Calculation Rate and based on the Calculation Method,
                           then Seller shall pay to Buyer the difference
                           thereof; and

                           (ii) if (x) the Purchase Price Adjustment Payment is
                           less than (y) the sum of $35,000,000 plus interest on
                           such amount from and including the Closing Date to
                           but excluding the Final Settlement Date at the
                           Calculation Rate and based on the Calculation Method,
                           Buyer shall pay to Seller the difference,

                           in each case, by wire transfer of immediately
                           available funds and in full satisfaction of Seller's
                           obligation under 2.09(c).

                           (d) In the event that no payment is required by
                           Seller to Buyer pursuant to Section 2.09(c) hereof,
                           Buyer shall pay to Seller the sum of $35,000,000 plus
                           interest on such amount from and including the
                           Closing Date to but excluding the date of payment, at
                           the Calculation Rate and based on the Calculation
                           Method by wire transfer of immediately available
                           funds to an account designated by Seller. Such
                           payment shall be made within 10 days after


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<PAGE>

                           Final Working Capital and Final Long-Term Tangible
                           Assets have been determined pursuant to Section
                           2.10(b).



                  (e) Article 7 of the Purchase Agreement is hereby amended by
         inserting the following section immediately following the last sentence
         of Section 7.08.

                           "Section 7.09. SUPPLY AGREEMENT. After the Closing,
                           Seller and Buyer shall negotiate in good faith and
                           use their reasonable best efforts to enter into a
                           supply agreement, pursuant to which Purchaser and its
                           Affiliates will supply to Seller and its Affiliates
                           the products manufactured by the Business under
                           Product Line 080 (as described in Annex F)."

                  (f) Article 7 of the Purchase Agreement is hereby further
         amended by inserting the following section immediately following the
         last sentence of Section 7.09.

                           "Section 7.10. GUARANTIES AND SIMILAR INSTRUMENTS.
                           Following the Closing, Buyer will use its reasonable
                           best efforts to cause itself or one of its Affiliates
                           to be substituted in all respects for Seller or its
                           Affiliates in respect of all obligations of Seller
                           and its Affiliates under all guaranties, letters of
                           credit, bid bonds, performance and other similar
                           bonds obtained by Seller or any of its Affiliates for
                           the benefit of any Acquired Subsidiary, including,
                           without limitation, such instruments set forth on
                           Schedule 7.10 hereto. If Buyer is unable to effect
                           such a substitution, it will use its reasonable best
                           efforts to obtain and have issued replacements for
                           each such guaranty, letter of credit, bid bond,
                           performance or other similar bond, each of which
                           shall be substantially similar to that being so
                           replaced and to obtain any amendments, novations,
                           releases, waivers, consents or approvals necessary to
                           release Seller and its Affiliates. Buyer agrees to
                           indemnify and hold harmless Seller and its Affiliates
                           from any and all damage, loss, liability and expense
                           (including, without limitation, reasonable attorneys'
                           fees and expenses) arising subsequent to the Closing
                           Date under all such guaranties, letters of credit,
                           bid bonds, performance and other similar


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                           bonds until all such guaranties, letters of credit
                           and bonds have been replaced and all obligations
                           thereunder have been released. Seller will furnish to
                           Buyer such information with respect to such
                           guaranties, letters of credit, bid bonds, performance
                           and other similar bonds as Buyer may require in order
                           to fulfill its obligations under this Section 7.10."

                  (g) Section 9.01(b) of the Purchase Agreement is hereby
         further amended by deleting the words "Seller or any Acquired
         Subsidiary" from the third sentence thereof and inserting in lieu
         thereof "Seller or any Affiliate of Seller".

                  (h) Section 9.02 of the Purchase Agreement is hereby amended
         by deleting Section 9.02(a) in its entirety and inserting the following
         section in lieu thereof:

                           Section 9.02 SELLER PLANS. (a) Except as expressly
                           set forth herein, Seller or its designated Affiliates
                           shall retain or reimburse Buyer for all liabilities
                           and obligations (including any underfunding of
                           defined benefit plans as of the Closing Date) in
                           respect of benefits accrued under all benefit plans
                           or arrangements maintained, administered or
                           contributed to by Seller or its Affiliates, including
                           the Employee Plans and International Plans, in
                           respect of each Transferred Employee, employee, or
                           former employee (including any beneficiary thereof).
                           Except as expressly set forth herein, no assets of
                           any benefit plans or arrangements maintained,
                           administered or contributed to by Seller or any
                           Affiliate thereof, including any Employee Plan or
                           International Plan, shall be transferred to Buyer or
                           any of its Affiliates or to any plan of Buyer or any
                           of its Affiliates; PROVIDED, that Seller shall not
                           retain, and Buyer shall assume, any and all
                           obligations and liabilities with respect to benefits
                           accrued by Transferred Employees during the
                           transitional services period as provided for in Annex
                           J; and PROVIDED FURTHER, that in the case of any
                           Employee Plan or International Plan maintained by an
                           Acquired Subsidiary (an "ACQUIRED SUBSIDIARY PLAN")
                           and pursuant to which such Acquired Subsidiary (or
                           any other Affiliate of Buyer) will retain any
                           pre-closing liabilities after the Closing Date, any
                           assets maintained in connection with such liabilities
                           by


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                           such Acquired Subsidiary (or in a trust or similar
                           entity established by such Acquired Subsidiary)
                           immediately prior to the Closing Date shall continue
                           to be maintained by such Acquired Subsidiary or
                           entity after the Closing Date. Benefit accruals in
                           respect of Transferred Employees under any Employee
                           Plan or International Plan other than an Acquired
                           Subsidiary Plan shall cease at the later of the
                           Closing Date or end of the transitional period as
                           provided for in Annex J. Seller and Buyer agree that,
                           except where alternative arrangements have been
                           specifically agreed in writing between Buyer and
                           Seller, all liabilities of Acquired Subsidiaries
                           under existing Acquired Subsidiary Plans providing
                           for retirement, deferred compensation or similar
                           benefits (an "ACQUIRED SUBSIDIARY RETIREMENT PLAN")
                           shall be retained by the applicable Acquired
                           Subsidiary following the Closing. Following the
                           Closing, Seller and Buyer shall use their best
                           efforts, and shall cause their respective actuaries
                           to cooperate, to agree on the actuarial present value
                           of the unfunded liabilities that are retained by
                           Acquired Subsidiaries under each Acquired Subsidiary
                           Retirement Plan pursuant to FASB 87 as of the Closing
                           Date (such present value with respect to each such
                           Plan, the "PRE-CLOSING ACQUIRED SUBSIDIARY PLAN
                           OBLIGATION" with respect to such Plan). If during the
                           90-day period following the Closing Date (or, in the
                           case of Acquired Subsidiary Retirement Plans for
                           which plan documents were not made available to Buyer
                           or one of its Affiliates prior to the Closing Date,
                           within the 90-day period following the discovery
                           thereof), Seller and Buyer are unable to agree on the
                           Pre-Closing Acquired Subsidiary Plan Obligation with
                           respect to any Acquired Subsidiary Retirement Plan,
                           they shall promptly refer the matter to a mutually
                           acceptable, internationally recognized actuarial firm
                           with no material relationship with Buyer, Seller or
                           their Affiliates (the "ACTUARIAL REFEREE"). The
                           parties shall instruct the Actuarial Referee to
                           determine the Pre-Closing Acquired Subsidiary Plan
                           Obligation with respect to such Plan as promptly as
                           practicable, and such determination shall be final
                           and binding upon Seller and Buyer. The costs of the
                           review by the Actuarial Referee shall be borne
                           equally by Seller and Buyer. "FINAL PRE-CLOSING
                           ACQUIRED SUBSIDIARY PLAN OBLIGATION" with respect to
                           any Acquired Subsidiary Retirement Plan shall


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                           mean (i) the Pre-Closing Acquired Subsidiary Plan
                           Obligation with respect to such Plan as mutually
                           agreed between Buyer and Seller or, (ii) in the event
                           such matter is submitted to the Actuarial Referee,
                           the Pre-Closing Acquired Subsidiary Plan Obligation
                           with respect to such Plan as determined by the
                           Actuarial Referee. Within 10 days after the Final
                           Pre-Closing Acquired Subsidiary Plan Obligation with
                           respect to any Acquired Subsidiary Retirement Plan
                           has been determined, Seller shall pay to Buyer an
                           amount equal to the Final Pre-Closing Acquired
                           Subsidiary Plan Obligation with respect to such Plan,
                           together with interest on such amount from and
                           including the Closing Date to but excluding the date
                           of payment, at the Calculation Rate and based on the
                           Calculation Method. All liabilities with respect to
                           benefits under the Acquired Subsidiary Retirement
                           Plans as of and after the Closing Date shall be
                           Assumed Liabilities. All health care and dependant
                           care flexible spending accounts maintained with
                           respect to Transferred Employees under the Seller's
                           cafeteria plan shall be transferred to the Buyer or
                           one of its Affiliates.

                  (i) Article 9 of the Purchase Agreement is hereby further
         amended by inserting the following section immediately following the
         last sentence of Section 9.05:

                           SECTION 9.06. CANADIAN EMPLOYEES. Notwithstanding
                           anything in this Agreement to contrary, (i) for
                           purposes of this Agreement, "Business Employees"
                           shall include the nine Canadian employees of Thomas &
                           Betts Ltd. previously identified by Seller to Buyer
                           or an Affiliate of Buyer (such employees, the
                           "CANADIAN EMPLOYEES"), and (ii) for purposes of this
                           Agreement, the term "Business Employee" as used in
                           the definition of "International Plan" shall also be
                           understood to include the Canadian Employees.

                  (j) Article 10 of the Purchase Agreement is hereby amended by
         deleting Section 10.01(b) in its entirety and inserting in lieu thereof
         the following:

                           Notwithstanding the foregoing, in the event that all
                           of the conditions set forth in this Article 10 are
                           satisfied with


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<PAGE>

                           respect to the Key Countries and the condition set
                           forth in Section 10.02(d) is satisfied, but such
                           conditions (except for the condition set forth in
                           Section 10.02(d)) are not satisfied with respect to
                           one or more other jurisdictions, Seller and Buyer
                           agree to consummate the Closing with respect to those
                           assets and liabilities of the Business for which (1)
                           all required approvals and consents described in
                           Section 10.01(a) have been obtained, or (2) no
                           approvals or consents are required (a "PRIMARY
                           CLOSING"). The closing or closings with respect to
                           the Purchased Assets and Assumed Liabilities not
                           transferred, assigned, purchased and accepted at the
                           Primary Closing (each, a "SUBSEQUENT CLOSING") shall
                           occur as promptly as practical after receipt of the
                           remaining approvals and consents referred to in
                           Section 10.01(a). From the Primary Closing, the
                           entirety of the Business shall be operated for the
                           benefit and detriment of Buyer.

                  (k) Article 13 of the Purchase Agreement is hereby amended by
         inserting the following section immediately following the last sentence
         of Section 13.12:

                           "SECTION 13.13. REPRESENTATIONS AND WARRANTIES;
                           INTERPRETATION. Seller and Buyer acknowledge and
                           agree that all representations and warranties with
                           respect to the subject matter of this Agreement are
                           contained in this Agreement, and that no
                           representations or warranties, express or implied,
                           are made by either party or their respective
                           Affiliates in any other document or instrument that
                           is delivered to effect the transactions contemplated
                           by this Agreement. All documents and instruments
                           delivered pursuant to this Agreement and shall be
                           construed consistently with this Agreement. In the
                           event of any inconsistencies, the terms of this
                           Agreement shall control."

                  (l) Annex A to the Purchase Agreement is hereby amended by
         deleting Item 1 thereof in its entirety and inserting in lieu thereof
         the following:

                          "1. Seller will contribute certain U.S. assets
                           primarily related to the Business to Augat, Inc. The
                           parties will mutually agree in good faith on steps to
                           the Reorganization regarding contributions before
                           such contributions are made.


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                           All other U.S. assets primarily related to the
                           Business will be transferred directly by Seller or an
                           Affiliate of Seller to Buyer or a Buyer Designee at
                           the Closing.

                  (m) Annex A to the Purchase Agreement is hereby further
         amended by deleting Item 3 thereof in its entirety and inserting in
         lieu thereof the following:

                           3. Seller will move external debt (except as
                           otherwise agreed between Seller and Buyer) and cash,
                           cash equivalents, marketable securities and similar
                           investments out of Acquired Subsidiaries; PROVIDED
                           that Seller may leave up to $5,000,000 in the
                           aggregate of cash in the Acquired Subsidiaries at
                           Closing; and PROVIDED FURTHER, that if more than
                           $5,000,000 in the aggregate of cash is left in the
                           Acquired Subsidiaries at Closing, Seller shall
                           indemnify Buyer and its Affiliates for any costs,
                           including, without limitation, Taxes in repatriating
                           such amount of cash in excess of $5,000,000. For each
                           Acquired Subsidiary, Seller shall settle or write off
                           all intercompany loans, intercompany payables and
                           intercompany receivables of each Acquired Subsidiary
                           effective as of or prior to the Closing Date.

                  (n) Annex B to the Purchase Agreement is hereby amended by:

                           (i) deleting Item 7 of Annex B in its entirety and
                  inserting in lieu thereof the following:

                           "7. Certain assets (trade receivables and inventory)
                           of T&B Ltd. (Canada) from the product lines listed in
                           Annex F. These assets will be contributed to Thomas &
                           Betts Photon Systems Inc., a Canadian subsidiary of
                           Seller, and the shares of such subsidiary will be
                           sold to Buyer or a Buyer Designee."

                           (ii) inserting the following immediately following
                  Item 10 of Annex B:

                           "10. All accounts payable and property, plant and
                           equipment with respect to the Bluffton, SC sales
                           office, if any, and the Grapevine, TX and Carlsbad,
                           CA sales offices and the Irvine, CA sales office.


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                           11. Inventory relating to the product lines listed in
                           Annex F owned by Thomas & Betts Pty. Ltd., an
                           Australian subsidiary of Seller.

                           12. Property, plant and equipment, inventory,
                           accounts payable and certain other assets of T&B
                           Corporation relating to the Business with respect to
                           the Irvine, CA, Inman, SC, Romeoville, IL, Downers
                           Grove, IL, Rochelle, IL, and Brooksville, FL
                           facilities and Thomas & Betts Corporation's
                           headquarters in Memphis, TN.

                  (o) Schedule 3.03 to the Purchase Agreement is hereby amended
         by deleting Schedule 3.03 in its entirety and substituting in lieu
         thereof a new Schedule 3.03 in the form attached to this Amendment as
         Schedule 3.03.

                  (p) Schedule 3.06(b) to the Purchase Agreement is hereby
         amended by deleting Schedule 3.06(b) in its entirety and substituting
         in lieu thereof a new Schedule 3.06(b) in the form attached to this
         Amendment as Schedule 3.06(b).

                  (q) Schedule 3.10 to the Purchase Agreement is hereby amended
         by deleting Schedule 3.10 in its entirety and substituting in lieu
         thereof a new Schedule 3.10 in the form attached to this Amendment as
         Schedule 3.10.

                  (r) Schedule 3.11 to the Purchase Agreement is hereby amended
         by deleting Schedule 3.11 in its entirety and substituting in lieu
         thereof a new Schedule 3.11 in the form attached to this Amendment as
         Schedule 3.11.

                  (s) Schedule 3.14(b) to the Purchase Agreement is hereby
         amended by deleting Schedule 3.14(b) in its entirety and substituting
         in lieu thereof a new Schedule 3.14(b) in the form attached to this
         Amendment as Schedule 3.14(b).

                  (t) Schedule 3.19 to the Purchase Agreement is hereby amended
         by deleting Schedule 3.19 in its entirety and substituting in lieu
         thereof a new Schedule 3.19 in the form attached to this Amendment as
         Schedule 3.19.


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                  (u) The Schedules to the Purchase Agreement are hereby amended
         by inserting immediately after Schedule 5.01 thereof a new Schedule
         7.10 in the form attached to this Amendment as Schedule 7.10.

          2. DEFINED TERMS. Defined terms used herein but not otherwise defined
herein shall have the meanings specified in the Purchase Agreement.

          3.                        CAPTIONS. The captions in this Amendment
are included for convenience of reference only and shall be ignored in the
construction or interpretation of the provisions of this Amendment.

          4.                        COUNTERPARTS; EFFECTIVENESS. This
Amendment may be signed in any number of counterparts, each of which shall be
an original, with the same effect as if the signatures thereto and hereto
were upon the same instrument. This Amendment shall become effective when
each party to this Amendment shall have received a counterpart hereof signed
by the other party hereto.

          5. GOVERNING LAW. This Amendment shall be governed by and construed in
accordance with the laws of the State of New York, without regard to the
conflicts of law rules of such state.

          6. AGREEMENT AS AMENDED. This Amendment is limited as specified and
shall not constitute a modification, acceptance or waiver of any other provision
of the Purchase Agreement. From and after the date hereof, all references to the
Purchase Agreement shall be deemed references to the Purchase Agreement as
amended and supplemented hereby.


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         IN WITNESS WHEREOF, the parties have caused this Amendment to be duly
executed in their respective corporate names by their respective officers, each
of whom is duly and validly authorized and empowered, all as of the day and year
first written above.



                                            THOMAS & BETTS CORPORATION

                                            By: ____________________________
                                                Name:
                                                Title:



                                            TYCO GROUP S.A.R.L.


                                            By: ____________________________
                                                Name:
                                                Title: