<PAGE>

                                                                   EXHIBIT 3.6.1



                 AMENDMENT NO. 1 TO THE ASSET PURCHASE AGREEMENT

                  THIS AMENDMENT NO. 1 TO THE ASSET PURCHASE AGREEMENT (the
"Amending Agreement") is made and is effective the 4th day of May, 2001, by and
between CELESTICA CORPORATION, a Delaware corporation ("Buyer"), and AVAYA INC.,
a Delaware corporation ("Seller").

                  WHEREAS Buyer and Seller entered into an Asset Purchase
Agreement (the "Asset Purchase Agreement") dated as of February 19, 2001,
providing, on the terms and conditions therein set forth, for the purchase by
Buyer from Seller and the sale by Seller to Buyer of the Purchased Assets;

                  AND WHEREAS Buyer and Seller wish to amend the Asset Purchase
Agreement as hereinafter provided to (i) update certain schedules thereto and
(ii) accurately reflect the parties' intentions with respect to the purchase and
sale of the Denver and Little Rock Purchased Inventory;

                  NOW THEREFORE THIS AMENDMENT NO. 1 TO THE ASSET PURCHASE
AGREEMENT WITNESSES THAT in consideration of the respective covenants and
agreements of the parties herein contained and for other good and valuable
consideration (the receipt and sufficiency of which are acknowledged by each
party), the parties agree as follows:

1. DEFINITIONS. Unless otherwise expressly defined herein, all terms which
appear in this Amending Agreement (including the recitals hereto) and which are
defined in the Asset Purchase Agreement shall have the respective meanings given
to them in the Asset Purchase Agreement.

2. AMENDMENTS TO THE ASSET PURCHASE AGREEMENT. The Asset Purchase Agreement is
amended as follows:

     (a)  the definition of "Delayed Closing" in Section 1.1 is hereby amended
          by deleting the phrase "Denver and Little Rock Inventory Closing" and
          replacing it with the phrase "Inventory Closings";

     (b)  the definition of "Delayed Closing Date" in Section 1.1 is hereby
          amended by deleting the phrase "Denver and Little Rock Inventory
          Closing Date" and replacing it with the phrase "Inventory Closing
          Dates";

     (c)  the definition of "Delayed Purchased Assets" in Section 1.1 is hereby
          deleted in its entirety and replaced with "means, collectively, the
          Delayed Shreveport Purchased Assets, the Denver Purchased Inventory,
          the Little Rock Purchased Inventory, the Denver Purchase Orders and
          the Little Rock Purchase Orders";

     (d)  the definitions of "Denver and Little Rock Inventory Closing", "Denver
          and Little Rock Inventory Closing Date", "Denver and Little Rock
          Inventory Purchase Price", "Denver and Little Rock Inventory
          Schedule", "Denver and Little Rock Purchase Orders", "Denver and
          Little Rock Purchased Inventory", "Initial Denver and Little Rock
          Inventory Net Book Value" and "Initial Denver and Little Rock


<PAGE>

                                       -2-


          Inventory Net Book Value of the Third Auditor" in Section 1.1 are
          hereby deleted in their entirety;

     (e)  the following definitions are hereby inserted in alphabetical order in
          Section 1.1 of the Asset Purchase Agreement:

          "Applicable Inventory Purchase Price" has the meaning assigned in
          Section 2.3(c)(i).

          "Denver Purchase Orders" means, collectively, all purchase order
          Contracts relating to the Denver Purchased Inventory.

          "Denver Purchased Inventory" means, on any Inventory Closing Date, the
          Purchased Inventory located at the Denver Premise which is to be
          purchased by Buyer hereunder on such Inventory Closing Date.

          "Initial Inventory Net Book Value" has the meaning assigned in Section
          2.3(c)(iv).

          "Initial Inventory Net Book Value of the Third Auditor" has the
          meaning assigned in Section 2.3(c)(iv).

          "Inventory Closing" means, in respect of a purchase and sale of any
          Denver Purchased Inventory or any Little Rock Purchased Inventory, or
          both, the completion of the purchase and sale of such Purchased
          Inventory pursuant to and in accordance with the terms of this
          Agreement.

          "Inventory Closing Date" means the date on which Denver Purchased
          Inventory or Little Rock Purchased Inventory or both are transferred
          to Buyer in accordance with Section 7.1(c).

          "Inventory Purchase Price" has the meaning assigned in Section
          2.3(c)(i).

          "Inventory Schedule" has the meaning assigned in Section 2.3(c)(ii).

          "Little Rock Purchase Orders" means, collectively, all purchase order
          Contracts relating to the Little Rock Purchased Inventory.

          "Little Rock Purchased Inventory" means, on any Inventory Closing
          Date, the Purchased Inventory located at the Little Rock Premise which
          is to be purchased by Buyer hereunder on such Inventory Closing Date.

     (f)  Section 2.1 is hereby amended by:

         (i) deleting the phrase "Sections 2.1(a) through 2.1(j)"
             and replacing it with the phrase "Sections 2.1(a)
             through 2.1(k)";


<PAGE>

                                       -3-


        (ii) deleting the word "and" after the phrase "the Business Records" in
             clause (i);

       (iii) deleting the "." and replacing it with "; and" at the end of
             clause (j); and

        (iv) adding the following provision after clause (j):

             "(k)   the furniture and equipment and other similar items owned
                    and used by Seller at the cafeteria in the Denver Premise.";

     (g)  Section 2.3(c) is hereby deleted in its entirety and replaced by the
          following:

              "(c)  Inventory Closings

                    (i) In consideration of the sale, transfer, assignment,
               conveyance and delivery by Seller of the Denver Purchased
               Inventory and the Little Rock Purchased Inventory, Buyer shall
               pay to Seller on each Inventory Closing Date, the net book value
               of the Purchased Inventory to be purchased on such Inventory
               Closing Date (as may be adjusted in accordance with this Section
               2.3(c), each the "APPLICABLE INVENTORY PURCHASE PRICE") and, on
               the last Inventory Closing Date, TWENTY SEVEN MILLION DOLLARS
               ($27,000,000) (together with the Applicable Inventory Purchase
               Price, the "INVENTORY PURCHASE PRICE", and the Inventory Purchase
               Price together with the Initial Purchase Price and the Shreveport
               Purchase Price, the "PURCHASE PRICE") in cash by wire transfer of
               immediately available funds to an account designated by Seller's
               written instructions to Buyer at least two (2) Business Days
               prior to the applicable Inventory Closing. The net book value of
               the Denver Purchased Inventory and the Little Rock Purchased
               Inventory to be purchased and sold on each Inventory Closing Date
               shall be determined in accordance with this Section 2.3(c).

                    (ii) As close as possible to each Inventory Closing Date,
               but in any event not more than five (5) Business Days prior
               thereto, Seller will in good faith prepare and deliver to Buyer a
               schedule (the "INVENTORY SCHEDULE") setting forth the net book
               value of the Purchased Inventory to be purchased and sold on such
               Inventory Closing Date. In order to prepare the Inventory
               Schedule for such Inventory Closing Date, Buyer shall provide
               Seller full access during regular business hours to the Denver
               Premise and the Little Rock Premise, as appropriate, and the
               relevant records necessary to prepare the Inventory Schedule. The
               Inventory Schedule shall be prepared in a manner consistent with
               the preparation of the Initial Balance Sheet. During such five
               (5) day period, Seller and Buyer shall jointly conduct a physical
               inventory of the Purchased Inventory to be purchased and sold on
               such Inventory Closing Date. To the extent Buyer agrees with
               Seller's calculation of the net book value of the Purchased
               Inventory to be purchased and sold on such Inventory


<PAGE>

                                       -4-


               Closing Date as set forth in the Inventory Schedule for such
               Inventory Closing Date, or if Seller and Buyer agree on a
               different net book value amount, Buyer shall pay Seller on such
               Inventory Closing Date such agreed upon amount. To the extent
               Buyer and Seller cannot reasonably agree on the net book value of
               the Purchased Inventory to be purchased and sold on such
               Inventory Closing Date by the day immediately prior to such
               Inventory Closing Date, Buyer shall nevertheless be obligated to
               pay Seller on such Inventory Closing Date the net book value
               amount set forth in the Inventory Schedule for such Inventory
               Closing Date, subject to the audit rights set forth in Section
               2.3(c)(iii) below.

                    (iii) To the extent Buyer and Seller cannot reasonably agree
               on the net book value of the Purchased Inventory to be purchased
               and sold on an Inventory Closing Date, promptly following such
               Inventory Closing Date, Seller's Auditor and Buyer's Auditor
               shall select the Third Auditor who shall definitively decide the
               net book value of the Purchased Inventory to be purchased and
               sold on such Inventory Closing Date. The Third Auditor will be
               given full access by Buyer, during regular business hours, to the
               relevant records and other work papers necessary to review the
               Inventory Schedule. Buyer and Seller shall each pay one-half of
               the fee charged by the Third Auditor, and each shall be solely
               responsible for any fees charged by auditors of such party.

                    (iv) An amount equal to the net book value of the Purchased
               Inventory to be purchased and sold on any Inventory Closing Date
               set forth in the Inventory Schedule shall be referred to as the
               "INITIAL INVENTORY NET BOOK VALUE." An amount equal to the net
               book value of the Purchased Inventory to be purchased and sold on
               such Inventory Closing Date as determined by the Third Auditor
               shall be referred to as the "INITIAL INVENTORY NET BOOK VALUE OF
               THE THIRD AUDITOR." If the Initial Inventory Net Book Value in
               respect of any Inventory Closing is less than the Initial
               Inventory Net Book Value of the Third Auditor, then Buyer shall
               pay the difference between such amounts to Seller in cash by wire
               transfer of immediately available funds to an account designated
               by Seller's written instructions to Buyer, and if the Initial
               Inventory Net Book Value in respect of any Inventory Closing is
               greater than the applicable Initial Inventory Net Book Value of
               the Third Auditor, then Seller shall pay the difference between
               such amounts to Buyer in cash by wire transfer of immediately
               available funds to an account designated by Buyer's written
               instructions to Seller. Any such payment shall be made on or
               before 60 calendar days after the applicable Inventory Closing
               Date, and any such payment shall be considered an addition or
               reduction, as applicable, to the Purchase Price.";

     (h)  Section 2.4 is hereby amended by deleting the phrase "Denver and
          Little Rock Purchase Orders" in each case and replacing it with
          "Denver Purchase Orders and Little Rock Purchase Orders";


<PAGE>

                                      -5-


     (i)  Sections 2.6(d) and 2.6(e) are hereby amended by deleting in its
          entirety the phrase "Denver and Little Rock Purchase Order" in each
          case and replacing it with "Denver Purchase Order or a Little Rock
          Purchase Order" and deleting in its entirety the phrase "Denver and
          Little Rock Inventory Closing Date" in each case and replacing it with
          "Inventory Closing Date";

     (j)  Section 3.16 is hereby amended by deleting the phrase "Denver and
          Little Rock Inventory Closing Date" in each case and replacing it with
          "applicable Inventory Closing Date";

     (k)  Section 5.4(f) is hereby amended by deleting the first sentence
          thereof in its entirety and replacing it with the following:

         "From and after the Effective Time on the Initial Closing Date, Buyer
          shall be responsible for all accrued, unused vacation balances owed to
          Transferred Employees who are Represented Employees who elect, prior
          to the Initial Closing Date, to transfer such accrued, unused vacation
          balances to their employment with Buyer and Seller shall deliver to
          the Buyer at least one (1) Business Day prior to the Initial Closing
          Date a list of all such Transferred Employees, which list shall set
          out the accrued, unused vacation balances so transferred and the
          applicable hourly wage rate of such Transferred Employees. The Initial
          Purchase Price shall be reduced by an amount equal to the aggregate of
          all accrued, unused vacation balances transferred to Buyer in
          accordance with this Section 5.4(f).";

     (l)  Section 7.1(c) is hereby deleted in its entirety and replaced by the
          following:

          "Subject to compliance with the terms and conditions hereof, the
          transfer of the Denver Purchased Inventory and the Little Rock
          Purchased Inventory and the assignment and assumption of the related
          Denver Purchase Orders and Little Rock Purchase Orders, as the case
          may be, shall be effective on a sequential basis in accordance with a
          timetable to be mutually agreed by Seller and Buyer during a period of
          time which shall begin on the Initial Closing Date and shall end no
          later than October 1, 2001. At the Effective Time on each Inventory
          Closing Date, Seller will transfer to Buyer title to any Denver
          Purchased Inventory and any Little Rock Purchased Inventory being
          transferred on such date.";

     (m)  Exhibit A to Schedule 1.1(a) of the Asset Purchase Agreement is hereby
          deleted in its entirety and replaced with Schedule 1.1(a)(A) attached
          to this Amending Agreement;

     (n)  Exhibit A to Schedule 1.1(b) of the Asset Purchase Agreement is hereby
          deleted in its entirety and replaced with Schedule 1.1(b)(A) attached
          to this Amending Agreement;

     (o)  Exhibit B to Schedule 1.1(c) of the Asset Purchase Agreement is hereby
          deleted in its entirety and replaced with Schedule 1.1(c)(B) attached
          to this Amending Agreement;


<PAGE>
                                      -6-


     (p)  Schedule 2.1(b) of the Asset Purchase Agreement, together with the
          exhibits thereto, is hereby deleted in its entirety and replaced with
          Schedule 2.1(b) attached to this Amending Agreement;

     (q)  Schedule 2.1(c) of the Asset Purchase Agreement is hereby deleted in
          its entirety and replaced with Schedule 2.1(c) attached to this
          Amending Agreement;

     (r)  Schedule 2.2(j) of the Asset Purchase Agreement, together with the
          exhibits thereto, is hereby deleted in its entirety and replaced with
          Schedule 2.2(j) attached to this Amending Agreement;

     (s)  Exhibit A to Schedule 2.4(a) of the Asset Purchase Agreement is hereby
          deleted in its entirety and replaced with Schedule 2.4(a)(A) attached
          to this Amending Agreement;

     (t)  Schedule 3.9(a) of the Asset Purchase Agreement is hereby deleted in
          its entirety and replaced with Schedule 3.9(a) attached to this
          Amending Agreement;

     (u)  Exhibits A, B2, C1 and E to Schedule 3.10 of the Asset Purchase
          Agreement are hereby deleted in their entirety and replaced with
          Schedules 3.10(A), 3.10(B2) 3.10(C1) and 3.10(E) attached to this
          Amending Agreement, respectively; and

     (v)  Schedule 3.18 of the Asset Purchase Agreement is hereby deleted in its
          entirety and replaced with Schedule 3.18 attached to this Amending
          Agreement.

3. COVENANT OF SELLER. Seller agrees that it shall repair all leaks in the roof
at the Little Rock Premise, which leaks are in existence on the date hereof, and
be liable for all costs related thereto. If such repair has not been completed
within 30 days of the date hereof, Buyer may have the repairs performed and
invoice Seller for reimbursement of the cost of the repairs, and Seller shall
reimburse Buyer for such costs.

4. CONFIRMATION OF THE ASSET PURCHASE AGREEMENT. Except as specifically provided
for in the foregoing provisions of this Amending Agreement, the Asset Purchase
Agreement shall continue in full force and effect and each of Buyer and Seller
hereby confirms the terms of the Asset Purchase Agreement, as so amended. This
Amending Agreement and the Asset Purchase Agreement shall be read, interpreted,
construed and have effect as, and shall constitute, one agreement with the same
effect as if the amendments made by this Amending Agreement had been contained
in the Asset Purchase Agreement as of the date hereof.

5. GOVERNING LAW. This Agreement shall be governed by the laws of the State of
New York.


<PAGE>


                                      -7-


6. COUNTERPARTS. This Amending Agreement may be executed in one or more
counterparts, each of which when so executed shall constitute an original and
all of which shall constitute one and the same agreement.

                  IN WITNESS WHEREOF the parties hereto have executed this
Amendment No. 1 to the Asset Purchase Agreement.

                                    CELESTICA CORPORATION


                                     by: ______________________________________
                                         Name: Rahul Suri
                                         Title:  Authorized Signatory


                                     AVAYA INC.


                                      by: _____________________________________
                                      Name:
                                      Title: