<PAGE>
                                                                    Exhibit 10.6
                                                                    ------------


                            ACT MANUFACTURING, INC.


                                      AND


                           THE CHASE MANHATTAN BANK





                            SHARE PLEDGE AGREEMENT


                         ----------------------------

                         dated as of 14 October, 1998

                         ----------------------------





                                  Arthur Cox
                               Earlsfort Centre
                              Earls fort Terrace
                                   Dublin 2

                   WJ1331/MdeC-C                   12/10/98
<PAGE>
 
THIS PLEDGE AGREEMENT, dated as of October, 14, 1998, is made between

ACT MANUFACTURING, INC. (the "Pledgor") of the one part, and
                              -------

THE CHASE MANHATTAN BANK ("Chase"), individually and as collateral agent for
                           ----- 
the Lenders under the Credit Agreement defined below, having an address at One
Chase Square, Rochester, New York 14643 (the "Collateral Agent" and together
                                              ---------------- 
with the Lenders, the "Secured Parties") of the other part.
                       --------------- 

WHEREAS, the Pledgor is entering into a Credit Agreement of even date herewith
(as the same may be modified, amended, supplemented or restated from time to
time, the "Credit Agreement"), with Chase, as administrative, documentation,
           ----------------
collateral and syndication agent, and the Lenders from time to time parties
thereto; and

WHEREAS, in connection with the execution and delivery of the Credit Agreement,
the Collateral Agent has requested that the Pledgor, and the Pledgor has agreed
to, enter into this Pledge Agreement (this "Pledge Agreement"), pursuant to
                                            ----------------
which the Pledgor is pledging and granting a security interest in the Pledged
Collateral (as hereinafter defined) in favour of the Collateral Agent for the
benefit of the Secured Parties.

NOW IT IS HEREBY AGREED that in consideration of the willingness of the Secured
Parties to enter into the Credit Agreement and of the Lenders to agree, subject
to the terms and conditions set forth therein, and at the request of the Pledgor
to make the Loans and issue Letters of Credit to the Borrower pursuant thereto,
and for other good and valuable consideration, receipt of which is hereby
acknowledged, it is hereby agreed as follows:

1.   Defined Terms
     -------------

     Except as otherwise expressly defined herein, all capitalized terms shall
     have the meanings ascribed to them in the Credit Agreement.

2.   Security Interest
     -----------------

     The Pledgor hereby deposits with, and pledges to. the Collateral Agent for
     itself and for the benefit of the other Secured Parties:

     (a)  the shares of capital stock listed on Schedule I hereto (the "Pledged
                                                ----------              -------
          Stock") of the companies listed on Schedule I hereto (the
          -----                              ----------
          "Companies"),
           ---------  
     (b)  the instruments, agreements and other documents in favour of the
          Pledgor listed on Schedule II hereto (the "Pledged Debt Documents");
                                                     ----------------------
          and

     (c)  any and all other additional investment property, securities,
          instruments and chattel
<PAGE>
 
                                       2

          paper which may from time to time be pledged by the Pledgor to the
          Collateral Agent for the benefit of the Secured Parties (the Pledged
          Stock, the Pledged Debt Documents and all other additional investment
          property, securities, instruments and chattel paper are sometimes
          herein referred to collectively as the "Pledged Collateral");

     and the Pledgor hereby grants to the Collateral Agent for itself and for
     the benefit of the other Secured Parties a security interest in all of
     the Pledged Collateral as security for the due and punctual payment and
     performance of the Secured Obligations described in Section 3 hereof.

3.   Secured Obligations
     -------------------  
     The pledge and security interest hereby granted shall secure the due and
     punctual payment and performance of the following liabilities and
     obligations of the Pledgor (herein called the "Secured Obligations"):

     (a)  The principal of and premium, if any, and interest on, and fees,
          charges and other amounts due in respect of the Loans;

     (b)  Any and all other obligations of the Pledgor to the Secured Parties
          under the Credit Agreement or under any agreement or instrument
          relating thereto, all as amended from time to time, including without
          limitation any Interest Rate Protection Agreements; and

     (c)  Any and all other obligations and Indebtedness of the Pledgor to the
          Secured Parties or any of them, whether direct or indirect, absolute
          or contingent, due or to become due, or now existing or hereafter
          arising, including without limitation any and all other fees,
          premiums, and penalties owing by the Pledgor to the Secured Parties or
          any of them.

4.   Special Warranties and Covenants of the Pledgor
     -----------------------------------------------   

     The Pledgor hereby warrants and covenants to the Secured Parties that:

     (a)  The Pledged Collateral is duly and validly pledged with the Secured
          Parties;

     (b)  The Pledgor has good title to the Pledged Collateral, free and clear
          of all Liens of every nature whatsoever except as expressly set forth
          or permitted under the Credit Agreement;

     (c)  All of the Pledged Stock has been duly and validly issued and is fully
          paid;
<PAGE>
 
                                       3

     (d)  If any additional shares of capital stock of any class of the
          Companies or if any promissory notes of the Companies or other
          securities of the Companies are acquired by any Pledgor after the date
          hereof, the same shall constitute Pledged Collateral and shall be
          deposited and pledged with the Collateral Agent for itself and for the
          benefit of the other Secured Parties as provided in Section 2 hereof
          simultaneously with such acquisition. The Pledgor will promptly notify
          the Collateral Agent of the date and amount of any loans made from
          time to time by any Pledgor to the Companies as permitted by the
          Credit Agreement;

     (e)  The Pledgor will not sell, convey or otherwise dispose of any of the
          Pledged Collateral, nor will the Pledgor create, incur or permit to
          exist any Lien whatsoever with respect to any of the Pledged
          Collateral or the proceeds thereof, other than Liens on or in the
          Pledged Collateral created hereby or which are otherwise required or
          permitted under the Credit Agreement;

     (f)  The Pledgor will not consent to or approve the issuance of any
          additional shares of capital stock of any class of the Companies,
          except for the issuance of additional shares of capital stock to a
          Pledgor as permitted by and in accordance with the terms of the Credit
          Agreement, provided that any such additional shares of capital stock
          shall be deposited and pledged with the Collateral Agent for itself
          and for the benefit of the other Secured Parties simultaneously with
          such issuance as provided in Section 2 hereof;

     (g)  The Pledged Debt Documents evidence the amount of outstanding
          indebtedness for money borrowed of the respective issuers thereof
          indicated on Schedule II hereto; and
                       -----------

     (h)  If any additional instruments, agreements or other documents are
          acquired by any Pledgor evidencing any additional indebtedness owing
          to such Pledgor, the same shall constitute a part of the Pledged Debt
          Documents and Pledged Collateral and shall be deposited and pledged
          with the Collateral Agent for itself and for the benefit of the other
          Secured Parties as provided in Clause 2 hereof simultaneously with
          such acquisition. The Pledgor will promptly notify the Collateral
          Agent of any loans made from time to time by such Pledgor as permitted
          by the Credit Agreement.

5.   Distributions
     -------------

     In case, upon the dissolution, winding up, liquidation or reorganization of
     the Companies whether in bankruptcy, insolvency or receivership proceedings
     or upon an assignment for the benefit of creditors or any other marshaling
     of the assets and liabilities of the Companies or otherwise, any sum shall
     be paid or any property shall be distributed upon or with respect to any of
     the Pledged Collateral, such sum shall be paid over to the
<PAGE>
 
                                       4

     Collateral Agent as collateral security for the Secured Obligations. In
     case any stock dividend shall be declared on any of the Pledged Collateral,
     or any share of stock or fraction thereof shall be issued pursuant to any
     stock split involving any of the Pledged Collateral, or any distribution of
     capital (excluding ordinary cash dividends) shall be made on any of the
     Pledged Collateral, or any property shall be distributed upon or with
     respect to the Pledged Collateral pursuant to recapitalization or
     reclassification of the capital of the Companies, the shares or other
     property so distributed shall be delivered to the Collateral Agent to be
     held as collateral security for the Secured Obligations.

6.   Events of Default
     -----------------

     There shall exist a default under this Pledge Agreement upon the happening
     of any of the following events or conditions (herein called "Events of
                                                                  ---------
     Default"):
     -------

     (a)  Default shall be made in the due and punctual payment of any principal
          of or premium, if any, or interest on any of the Secured Obligations
          as and when the same shall become due and payable (whether at maturity
          or at a date fixed for any prepayment or instalment or by declaration
          or acceleration or otherwise) and such default shall continue beyond
          the expiration of the applicable period of grace, if any; or

     (b)  The breach, violation or other nonperformance of any term, covenant,
          condition, agreement or obligation of the Pledgor contained herein; or

     (c)  Any other event of default (as defined or described in the Credit
          Agreement) shall occur.

7.   Rights and Remedies of Secured Parties
     --------------------------------------

     Upon the occurrence of any Event of Default, such default not having
     previously been remedied or cured, the Secured Parties shall have the
     following rights and remedies:

     (a)  All rights and remedies provided in this Pledge Agreement; and

     (b)  All rights and remedies provided in the Credit Agreement, the Notes,
          or in any other Facility Document, or in any other agreement, document
          or instrument pertaining to the Secured Obligations.

8.   Right to Transfer into Name of Collateral Agent, etc.
     ----------------------------------------------------

     In case there shall exist an Event of Default, but subject to the
     provisions of applicable law, the Collateral Agent may cause all or any of
     the Pledged Collateral to be transferred into its name or into the name of
     its nominee or nominees, as pledgee. So long as no
<PAGE>
 
                                       5

     Event of Default shall exist, the Pledgor shall be entitled to exercise as
     the Pledgor shall deem fit, but in a manner not inconsistent with the terms
     hereof or of the Secured Obligations, the voting power with respect to its
     respective Pledged Collateral.

9.   Right of Collateral Agent to Exercise Voting Power, etc.
     -------------------------------------------------------

     In case there shall exist an Event of Default, the Collateral Agent shall
     be entitled to exercise the voting power with respect to any or all of the
     Pledged Collateral, to receive and retain, as collateral security for the
     Secured Obligations, any and all dividends or other distributions at any
     time and from time to time declared or made upon any of the Pledged
     Collateral, and to exercise any and all rights of payment, conversion,
     exchange, subscription or any other rights, privileges or options
     pertaining to the Pledged Collateral as if it were the absolute owner
     thereof, including, without limitation, the right to exchange, at its
     discretion, any and all of the Pledged Collateral upon the merger,
     consolidation, reorganization, recapitalization or other readjustment of
     the Companies or, upon the exercise of any such right, privilege or option
     pertaining to the Pledged Collateral, and in connection therewith, to
     deposit and deliver any and all of the Pledged Collateral with any
     committee, depositary, transfer Collateral Agent, registrar or other
     designated agency upon such terms and conditions as the Collateral Agent
     may determine, all without liability except to account for property
     actually received, but the Collateral Agent shall have no duty to exercise
     any of the aforesaid rights, privileges or options and shall not be
     responsible for any failure to do so or delay in so doing.

10.  Right of Collateral Agent to Dispose of Collateral, etc.
     -------------------------------------------------------

     Upon the occurrence of an Event of Default, such default not having
     previously been remedied or cured, the power of sale pursuant to Section 19
     of the Conveyancing Act 1881 shall arise and be exercisable without the
     restrictions contained in Section 20 thereof and the Collateral Agent shall
     have the right at any time or times thereafter to sell, resell, assign and
     deliver all or any of the Pledged Collateral in one or more parcels by way
     of public or private sale. Unless the Pledged Collateral threatens to
     decline speedily in value or is of a type customarily sold on a recognized
     market, the Collateral Agent will give the Pledgor at least ten (10) days'
     prior written notice at the address of the Pledgor specified in Clause 21
     hereof of the time and place of any public sale thereof or of the time
     after which any private sale or any other intended disposition thereof is
     to be made. Any such notice shall be deemed to meet any requirement
     hereunder or under any applicable law that reasonable notification be given
     of the time and place of such sale or other disposition. Such notice may be
     given without any demand of performance or other demand, all such demands
     being hereby expressly waived by the Pledgor. All such sales shall be at
     such commercially reasonable price or prices as the Collateral Agent shall
     deem best and either for cash or on credit or for future delivery (without
     assuming any responsibility for credit risk). At any such sale or sales the
     Collateral Agent may purchase any or all of the Pledged Collateral to be
     sold upon such terms as the Collateral Agent may deem
<PAGE>
 
                                       6

     commercially reasonable. Upon any such sale or sales the Pledged Collateral
     so purchased shall be held by the purchaser absolutely free from any claims
     or rights of whatsoever kind or nature, including any equity of redemption
     and any similar rights, all such equity of redemption and any similar
     rights being hereby expressly waived and released by the Pledgor. In the
     event any consent, approval or authorization of any governmental agency
     will be necessary to effectuate any such sale or sales, the Pledgor shall
     execute, and hereby agrees to cause the Companies to execute, all such
     applications or other instruments as may be required.

11.  Power of Attorney
     -----------------

     The Pledgor hereby irrevocably appoints the Collateral Agent to be, while
     any Event of Default shall exist, the Pledgor's attorney and in the
     Pledgor's name and on its behalf and as the act and deed of the Pledgor to
     sign, seal, execute, deliver, perfect and do all deeds, instruments,
     mortgages and things as may be, or as the Collateral Agent may consider to
     be, requisite for carrying out any obligation imposed on the Pledgor under
     the Pledge Agreement, or for enabling the Collateral Agent to exercise its
     power of sale or other disposal referred to above or for carrying any such
     sale or other disposal made under such power into effect by executing
     instruments of transfer (or completing partially-completed instruments
     executed by the Pledgor), or exercising (but subject as therein provided
     with respect to voting) any of the rights and powers referred to above,
     including without limitation the appointment of any person as a proxy of
     the Pledgor. The Pledgor hereby undertakes to ratify and confirm all things
     done and document executed by the Collateral Agent in the exercise of the
     power of attorney conferred by this Clause.

     In the event of the Collateral Agent exercising the power of attorney
     hereby conferred, or conferred by the Power of Attorney, prior to the
     disposition of the Pledged Collateral pursuant to Clause 10 hereof the
     Collateral Agent shall immediately on the exercise of such power notify the
     Pledgor in writing of such exercise.

12.  Credit Agreement
     ----------------

     Notwithstanding any other provision of this Pledge Agreement, the rights of
     the parties hereunder are subject to the provisions of the Credit
     Agreement, including the provisions thereof pertaining to the rights and
     responsibilities of the Collateral Agent. Unless the context shall
     otherwise clearly indicate, the terms "Secured Party" and "Secured Parties"
     as used herein shall be deemed to include the Collateral Agent acting for
     itself and on behalf of the other Secured Parties pursuant to the Credit
     Agreement. The term "Collateral Agent" as used herein shall include The
     Chase Manhattan Bank or any other Person acting as Collateral Agent for the
     Secured Parties pursuant to the terms of the Credit Agreement.
<PAGE>
 
                                       7

13.  Collection of Amounts Payable on Account of Pledged Collateral, etc.
     -------------------------------------------------------------------

     Upon the occurrence and during the continuance of any Event of Default or
     default hereunder, the Collateral Agent may, but without obligation to do
     so, demand, sue for and/or collect any money or property at any time due,
     payable or receivable, to which it may be entitled hereunder, on account
     of, or in exchange for, any of the Pledged Collateral and shall have the
     right, for and in the name, place and stead of the Pledgor, to execute
     endorsements, assignments or other instruments of conveyance or transfer
     with respect to all or any of the Pledged Collateral.

14.  Care of Pledged Collateral in Collateral Agent's Possession
     -----------------------------------------------------------

     Beyond the exercise of reasonable care to assure the safe custody of the
     Pledged Collateral while held hereunder, the Collateral Agent shall have no
     duty or liability to collect any sums due in respect thereof or to protect
     or preserve rights pertaining thereto, and shall be relieved of all
     responsibility for the Pledged Collateral upon surrendering the same to the
     Pledgor.

15.  Proceeds of Collateral
     ----------------------

     The proceeds of any sale or sales of the Pledged Collateral, together with
     any other additional collateral security at the time received and held
     hereunder, shall be received and applied: first, to the payment of all
     costs and expenses of such sale, including reasonable legal fees; second,
     to the payment of the Secured Obligations in such order of priority as the
     Collateral Agent shall determine, and third, any surplus thereafter
     remaining shall be paid to the Pledgor or to whomever else may be legally
     entitled thereto (including, if applicable, any subordinated creditor of
     any Company or any Pledgor). By way of enlargement and not by way of
     limitation of the rights of the Collateral Agent under applicable law or
     the Credit Agreement, Notes, or other Facility Documents, but not
     withstanding any provision of the Credit Agreement, Notes, or other
     Facility Documents to the contrary, the Collateral Agent shall be entitled
     to allocate its application of the Pledged Collateral, and the proceeds
     thereof, to the Secured Obligations (including without limitation the
     Loans) in such proportions and in such order as the Collateral Agent, in
     its sole discretion, shall decide. In the event the proceeds of any sale,
     lease or other disposition of the Collateral hereunder are insufficient to
     pay all of the Secured Obligations in full, the Pledgor will be liable for
     the deficiency, together with interest thereon at the maximum rate provided
     in the Loans, and the cost and expenses of collection of such deficiency,
     including (to the extent permitted by law), without limitation, reasonable
     legal fees, expenses and disbursements.

16.  Waivers, etc.
     ------------

     The Pledgor hereby waives presentment, demand, notice, protest and, except
     as is
<PAGE>
 
                                       8

     otherwise provided herein, all other demands and notices in connection with
     this Pledge Agreement or the enforcement of the Secured Parties' rights
     hereunder or in connection with any Secured Obligations or any Pledged
     Collateral; consents to and waives notice of the granting of renewals,
     extensions of time for payment or other indulgences to any Company or the
     Pledgor or to any third party, or substitution, release or surrender of any
     collateral security for any Secured Obligation, the addition or release of
     persons primarily or secondarily liable on any Secured Obligation or on any
     collateral security for any Secured Obligation, the acceptance of partial
     payments on any Secured Obligation or on any collateral security for any
     Secured Obligation and/or the settlement or compromise thereof. No delay or
     omission on the part of the Secured Parties in exercising any right
     hereunder shall operate as a waiver of such right or of any other right
     hereunder. Any waiver of any such right on any one occasion shall not be
     construed as a bar to or waiver of any such right on any future occasion.
     The Pledgor further waives any right it may have to notice (other than any
     requirement of notice provided herein) or to a judicial hearing prior to
     the exercise of any right or remedy provided by this Pledge Agreement to
     the Collateral Agent and waives its rights, if any, to set aside or
     invalidate any sale duly consummated in accordance with the foregoing
     provisions hereof on the grounds (if such be the case) that the sale was
     consummated without a prior judicial hearing.

17.  Termination; Assignment, etc.
     ----------------------------

     This Pledge Agreement and the security interest in the Pledged Collateral
     created hereby shall terminate when all of the Secured Obligations have
     been paid and finally discharged in full; provided that the Lenders are no
     longer obligated to make Loans or issue Letters of Credit under the Credit
     Agreement. No waiver by the Collateral Agent or by any other holder of
     Secured Obligations of any default shall be effective unless in writing nor
     operate as a waiver of any other default or of the same default on a future
     occasion. In the event of a sale or assignment by any Secured Party of all
     or any of the Secured Obligations held by it, any Secured Party may assign
     or transfer its rights and interest under this Pledge Agreement in whole or
     in part to the purchaser or purchasers of such Secured Obligations,
     whereupon such purchaser or purchasers shall become vested with all of the
     powers and rights of such Secured Party hereunder.

18.  Reinstatement
     -------------

     Notwithstanding the provisions of Clause 17, this Pledge Agreement shall
     continue to be effective or be reinstated, as the case may be, if at any
     time any amount received by any Secured Party in respect of the Secured
     Obligations is rescinded or must otherwise be restored or returned by any
     such Secured Party upon the insolvency, bankruptcy, dissolution,
     liquidation or reorganization of any Company, the Pledgor or any other
     Credit Party or upon the appointment of any intervener or conservator of,
     or trustee or similar official for, any Company, the Pledgor, or any other
     Credit Party or any substantial part of their respective properties, or
     otherwise, all as though such payments had not been
<PAGE>
 
                                       9

     made.

19.  Governmental Approvals, etc.
     ---------------------------

     Upon the exercise by the Collateral Agent of any power, right, privilege or
     remedy pursuant to this Pledge Agreement which requires any consent,
     approval, qualification or authorization of any governmental authority or
     instrumentality, the Pledgor will execute and deliver, or will cause the
     execution and delivery of, all applications, certificates, instruments and
     other documents and papers that the Collateral Agent may be required to
     obtain for such governmental consent, approval, qualification or
     authorization.

20.  Restrictions on Transfer, etc.
     -----------------------------

     To the extent that any restriction imposed by the memorandum and articles
     of association of the Companies or any other document or instrument would
     in any way affect or impair the pledge of the Pledged Collateral hereunder
     or the exercise by the Collateral Agent of any right granted hereunder,
     including, without limitation, the right of the Collateral Agent to dispose
     of the Pledged Collateral upon the occurrence of any Event of Default, the
     Pledgor hereby waives such restrictions, and represents and warrants that
     it has caused the Companies to take all necessary action to waive such
     restrictions, and the Pledgor hereby agrees that it will take any further
     action which the Collateral Agent may reasonably request in order that the
     Collateral Agent may obtain and enjoy the full rights and benefits granted
     to the Collateral Agent by this Pledge Agreement free of any such
     restrictions.

21.  Notices
     -------

     All notices, consents, approvals, elections and other communications
     hereunder shall be in writing (whether or not the other provisions of this
     Pledge Agreement expressly so provide) and shall be deemed to have been
     duly given if delivered in accordance with the terms of the Credit
     Agreement.

22.  Miscellaneous
     -------------

     This Pledge Agreement shall inure to the benefit of and be binding upon the
     Collateral Agent and the Pledgor and its successors and assigns, and the
     term "Secured Parties" shall be deemed to include any other holder or
     holders of any of the "Secured Obligations. In case any provision in this
     Pledge Agreement shall be invalid, illegal or unenforceable, the validity,
     legality and enforceability of the remaining provisions shall not in any
     way be affected or impaired thereby. This Pledge Agreement may be executed
     in any number of counterparts and by the different parties hereto on
     separate counterparts, each of which shall be an original, but all of
     which, together shall constitute one instrument.
<PAGE>
 
                                      10

23.  Governing Law and Jurisdiction.
     ------------------------------

     This Pledge Agreement, including the validity hereof and the rights and
     obligations of the parties hereunder, shall be construed in accordance with
     and governed by the laws of the Ireland. The Pledgor, to the extent that it
     may lawfully do so, hereby consents to service of process, and hereby
     submits to the non exclusive jurisdiction of the Courts of Ireland.
<PAGE>
 

IN WITNESS WHEREOF, the parties have executed this Pledge Agreement as a sealed
instrument as of the date first above written.


ACT MANUFACTURING, INC.
in the presence of:

                                                    By:  /s/ John A. Pino
                                                        ------------------------
/s/ David L. Ruediger                               Name:  John A. Pino
                                                    Title: President

                                                    





COLLATERAL AGENT

THE CHASE MANHATTEN BANK,
as collateral Agent for the Secured Parties
in the presence of:


                                                    By:  /s/ Peter N. Langburd
                                                        ------------------------
/s/ David L. Ruediger                               Name: Peter N. Langburd
                                                    Title: Vice President