<PAGE>
 
                                                                   EXHIBIT 10.27

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

                           STOCK PURCHASE AGREEMENT

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

                                     Among

                             PRI AUTOMATION, INC.,

                             PRI SWITZERLAND, INC.

                                      and

             THE SHAREHOLDERS OF CHIPTRONIX HANDLING SYSTEMS GMBH

                            AND OF CHIPTRONIX GMBH


                           Dated as of May 19, 1998
<PAGE>
 
<TABLE>
<S>                     <C>                                                                   <C>
ARTICLE I PURCHASE AND SALE...................................................................  1
          Section 1.1   Purchase and Sale of Company Shares and Related Company
          Shares..............................................................................  1
          Section 1.2   Purchase Consideration................................................  1
          Section 1.3   Closing...............................................................  2
          Section 1.4   Accounting Treatment..................................................  4

ARTICLE II REPRESENTATIONS AND WARRANTIES OF THE SELLERS......................................  4
          Section 2.1   Corporate Status......................................................  4
          Section 2.2   Corporate Documents...................................................  5
          Section 2.3   Capital Structure.....................................................  5
          Section 2.4   Investments; Related Companies........................................  5
          Section 2.5   Financial Statements..................................................  6
          Section 2.6   Compliance with Applicable Laws.......................................  7
          Section 2.7   Litigation............................................................  8
          Section 2.8   Properties............................................................  8
          Section 2.9   Contracts.............................................................  8
          Section 2.10  Taxes................................................................. 10
          Section 2.11  Benefit Plans......................................................... 11
          Section 2.12  Absence of Certain Changes or Events.................................. 11
          Section 2.13  Officers, Directors and Key Employees................................. 13
          Section 2.14  Potential Conflicts of Interest....................................... 14
          Section 2.15  Finder's Fees......................................................... 14
          Section 2.16  Bank Accounts......................................................... 14
          Section 2.17  Environmental Matters................................................. 14
          Section 2.18  Insurance............................................................. 15
          Section 2.19  Employee Relations.................................................... 15
          Section 2.20  Proprietary Rights.................................................... 15
          Section 2.21  Certain Loans......................................................... 16
          Section 2.22  Customers and Vendors................................................. 16
          Section 2.23  Business Activity Restrictions........................................ 16

ARTICLE III REPRESENTATIONS AND WARRANTIES OF EACH SELLER..................................... 16
          Section 3.1   Authority............................................................. 16
          Section 3.2   Ownership............................................................. 17
          Section 3.3   Further Assurances.................................................... 17
          Section 3.4   Investment in PRI Common.............................................. 17
          Section 3.5   Tax Matters........................................................... 18

ARTICLE IV REPRESENTATIONS AND WARRANTIES OF PARENT AND THE
    PURCHASER................................................................................. 19
          Section 4.1 Corporate Status........................................................ 19
          Section 4.2 Authority............................................................... 19
</TABLE>
<PAGE>
 
<TABLE>
<S>       <C>           <C>                                                                   <C>
          Section 4.3   Investment Purpose.................................................... 19
          Section 4.4   Capitalization........................................................ 19

ARTICLE V INDEMNIFICATION..................................................................... 19
          Section 5.1   Agreement to Indemnify................................................ 19
          Section 5.2   Survival of Representations and Warranties............................ 20
          Section 5.3   Certain Limitations................................................... 20
          Section 5.4   Specific Representations.............................................. 20

ARTICLE VI GENERAL PROVISIONS................................................................. 21
          Section 6.1   Expenses.............................................................. 21
          Section 6.2   Notices............................................................... 21
          Section 6.3   Public Announcements.................................................. 22
          Section 6.4   Headings.............................................................. 22
          Section 6.5   Severability.......................................................... 22
          Section 6.6   Entire Agreement...................................................... 23
          Section 6.7   Assignment............................................................ 23
          Section 6.8   No Third Party Beneficiaries.......................................... 23
          Section 6.9   Amendment............................................................. 23
          Section 6.10  Governing Law......................................................... 23
          Section 6.11  Counterparts.......................................................... 23
          Section 6.12  Arbitration........................................................... 23
</TABLE>
<PAGE>
 
     STOCK PURCHASE AGREEMENT, dated as of May 19, 1998, among PRI Automation,
Inc., a Massachusetts corporation ("Parent"), PRI Switzerland, Inc., a
Massachusetts corporation (the "Purchaser"), and each of the persons listed on
                                ---------
Schedule A hereto, each of whom is referred to as a "Seller."
----------                                           ------

                             W I T N E S S E T H:
                             - - - - - - - - - -

     WHEREAS, the Sellers are all the quota holders of Chiptronix Handling
Systems GmbH, a Swiss corporation (the "Company"); and
                                        -------
     WHEREAS, Kerstin Czenkusch-Hans, being one of the Sellers, is the holder of
all the share capital of Chiptronix GmbH, a German corporation (the "Related
                                                                     -------
Company"); and
-------

     WHEREAS, all the issued and outstanding capital stock of the Purchaser is
owned by PRI Holdings, Inc. and PRI International Holdings, Inc., each of which
is a wholly-owned subsidiary of Parent;

     WHEREAS, each Seller wishes to sell to the Purchaser, and the Purchaser
wishes to purchase from each Seller, the quotas of the Company set forth
opposite his or her name on Schedule A (collectively, the "Company Shares"),
                            ----------                     --------------
upon the terms and subject to the conditions set forth herein; and

     WHEREAS, Mrs. Czenkusch-Hans wishes to sell to the Purchaser, and the
Purchaser wishes to purchase from her, all the share capital of the Related
Company as set forth opposite her name on Schedule A (collectively, the "Related
                                          ----------                     -------
Company Shares"), upon the terms and subject to the conditions set forth herein.
--------------

     NOW, THEREFORE, in consideration of the promises and the mutual agreements
and covenants hereinafter set forth, the Purchaser and each of the Sellers
hereby agree as follows:

                                   ARTICLE I
                               PURCHASE AND SALE

     Section 1.1 Purchase and Sale of Company Shares and Related Company Shares.
                 --------------------------------------------------------------
Upon the terms and subject to the conditions contained in this Agreement, at the
Closing, each Seller shall sell to the Purchaser, and the Purchaser shall
purchase from each Seller, the Company Shares and the Related Company Shares, if
any, set forth opposite each Seller's name on Schedule A.
                                              ----------

     Section 1.2 Purchase Consideration. The consideration for the purchase of
                 ----------------------
the Company Shares and the Related Company Shares shall be payable in the form
of shares of the 
<PAGE>
 
common stock, $.01 par value, of Parent ("PRI Common"), and shall consist of One
                                          ----------
Hundred Five Thousand (105,000) shares of PRI Common (the "PRI Shares"). The PRI
                                                           ----------
Shares shall be divided among the Sellers in proportion to the Company Shares
held by them, as set forth on Schedule A.
                              ----------

     Section 1.3 Closing.
                 -------

   (a) Subject to the terms and conditions of this Agreement, the sale and
purchase of the Company Shares and Related Company Shares contemplated by this
Agreement shall take place at a closing (the "Closing") to be held at the
                                              -------
offices of Foley, Hoag & Eliot LLP, Boston, Massachusetts at 10:00 a.m. Boston
time on May 20, 1998, or at such other place or at such other time or on such
other date as the Sellers and the Purchaser may mutually agree upon in writing
(the date on which the Closing takes place being the "Closing Date").
                                                      ------------

   (b) At the Closing:

       (i)    the Sellers shall deliver or cause to be delivered to the
              Purchaser duly executed and notarized deeds evidencing (A) the
              agreement of the Sellers to sell and transfer to the Purchaser the
              Company Shares, and (B) the approval of the quota holders of the
              Company of the transactions contemplated hereby and the amendment
              of the articles of incorporation of the Company to reflect such
              transactions, each in a form suitable to be published and recorded
              in the commercial register of the Kanton of St. Gallen
              (collectively, the "Company Transfer Documents"), substantially as
                                  --------------------------
              set forth in Exhibit A and Exhibit A-1 hereto, respectively;
                           ---------     -----------

       (ii)   the Sellers shall deliver or cause to be delivered to the
              Purchaser a duly executed and notarized Assignment of Shares
              evidencing the transfer and assignment to the Purchaser of the
              Related Company Shares (the "Related Company Transfer Document"),
                                            ---------------------------------
              in substantially the form of Exhibit B hereto;
                                           ---------

       (iii)  Parent shall execute and deliver to the Sellers a Registration
              Rights Agreement relating to the PRI Shares in the form attached
              hereto as Exhibit C (the "Registration Rights Agreement")
                        ---------       -----------------------------

       (iv)   each of the Sellers shall execute and deliver to the Purchaser a
              counterpart of the Registration Rights Agreement;

       (v)    each of the Sellers shall execute and deliver to the Purchaser an
              Escrow Agreement in the form attached hereto as Exhibit D (the
                                                              ---------
              "Escrow Agreement")
               ----------------


                                       2
<PAGE>
 
       (vi)   each of the Purchaser and the Escrow Agent named therein shall
              execute and deliver to each Seller a counterpart of the Escrow
              Agreement;

       (vii)  the Purchaser shall deliver to the Sellers evidence that all
              necessary corporate action has been taken by Parent to cause the
              issuance, as of the Closing Date or as soon as practicable
              thereafter, of nonqualified stock options to purchase an aggregate
              of 38,200 shares of PRI Common to those employees of the Company
              listed on Schedule B hereto, at an exercise price equal to the
                        ----------
              last sale price of the PRI Common as reported by the Nasdaq Stock
              Market on the date of grant, which options shall be consistent in
              form and substance with nonqualified stock options granted by
              Purchaser to its employees having comparable responsibilities,
              except that such options shall have a term of not less than ten
              years and one day;

       (viii) the Sellers shall deliver to Purchaser the legal opinion of Jorg
              Schoch as to the matters set forth in Exhibit E hereto;
                                                    ---------

       (ix)   Parent's independent public accountants, Coopers & Lybrand LLP
              (the "Accountants") shall deliver to Parent a letter concurring
                    -----------
              with the conclusions of managements of Parent and the Company as
              to the appropriateness of pooling of interests accounting for the
              transactions contemplated hereby under Accounting Principles Board
              Opinion No. 16;

       (x)    each Seller shall deliver to Parent an agreement in the form of
              Exhibit F hereto (the "Affiliate Lock-Up Agreement")
              ---------              ---------------------------

       (xi)   the Company and Ekkehard Hans shall enter into an Amendment to
              Employment Contract for Managing Director (the "Employment
              Agreement") in the form of Exhibit H, hereto;
                                         ---------

       (xii)  Ekkehard Hans shall deliver to the Company his non-interest
              bearing promissory note in the form of Exhibit H hereto, payable
                                                     ---------
              on or before December 31, 1998 evidencing the Hans Loan;

       (xiii) the Purchaser shall deliver to each Seller a stock certificate
              evidencing 90% of the number of shares of PRI Common set forth
              opposite such Seller's name on Schedule A hereto (rounded to the
                                             ----------
              nearest whole number of shares); and


                                       3
<PAGE>
 
               (xiv) the Purchaser shall deliver to the Escrow Agent stock
                     certificates representing the balance of the PRI Shares, to
                     be held and disposed of pursuant to the Escrow Agreement.

          (c)  Each Seller hereby appoints Ekkehard Hans, with full power of
substitution, the representative and attorney-in-fact of such Seller (the
"Sellers' Representative"), with full power and authority in the name of and for
 -----------------------
and on behalf of the undersigned to:

               (i)   issue such instructions to the Escrow Agent with respect to
                     the disposition of the PRI Shares held in escrow pursuant
                     to the Escrow Agreement as the Sellers' Representative
                     shall determine to be appropriate; and
 
               (ii)  to take such other actions in furtherance of the
                     transactions contemplated hereby as the Sellers'
                     Representative shall determine in his sole discretion to be
                     appropriate or advisable.

     This power of attorney, and the authority confirmed hereby, being coupled
with an interest, are irrevocable and shall not be terminable by any act or deed
of the undersigned, by the death or incapacity of the undersigned, by operation
of law or otherwise. Notwithstanding the foregoing, this power of attorney shall
terminate in the event that the Closing has not taken place by June 30, 1998.

     Section 1.4 Accounting Treatment. The parties intend that the acquisition
                 --------------------
by Purchaser of the Company Shares and the Related Company Shares shall be
treated as a pooling of interests for accounting purposes. No party to this
Agreement shall knowingly take any action, directly or indirectly, that would
cause the acquisition by Purchaser of the Company Shares and the Related Company
Shares to fail to qualify as a pooling of interests, including taking any action
that would alter the equity interests of the Company or the Related Company in a
way that would prohibit pooling of interests treatment for the acquisition.

                                  ARTICLE II
                        REPRESENTATIONS AND WARRANTIES
                                OF THE SELLERS

     Except as set forth in the disclosure schedule dated as of the date of this
Agreement delivered to Purchaser by the Sellers (the "Disclosure Schedule"), the
                                                      -------------------
Sellers, jointly and severally, represent and warrant to Purchaser and Parent as
follows:

     Section 2.1 Corporate Status. The Company is a corporation duly organized,
                 ----------------
validly existing and in good standing under the laws of Switzerland, with all
requisite corporate power to own, lease and operate its properties and to carry
on its business as now being conducted. The Company is duly qualified to do
business as a foreign corporation, and is in good standing, in each


                                       4
<PAGE>
 
other jurisdiction in which it owns or leases property or conducts business,
except where the failure to be so qualified does not have any effect that is, or
is reasonably likely to be, materially adverse to its results of operations or
financial condition (a "Company Material Adverse Effect").
                        -------------------------------

     Section 2.2 Corporate Documents. The Company has delivered to Purchaser
                 -------------------
true and complete copies of its articles of incorporation, as amended to date,
and its statutes, as amended to date (collectively, the "Charter Documents").
                                                         -----------------
The Charter Documents are in full force and effect and no further amendment or
restatement thereof has been adopted or proposed. The Company is not in
violation of any provision of the Charter Documents. The minute books and
owners' book of the Company, which have heretofore been made available to
Purchaser, are true and complete and are the only minute books and owners' book
of the Company. Ekkehard D. Hans is the sole Managing Director and officer of
the Company.

     Section 2.3 Capital Structure. The authorized share capital of the Company
                 -----------------
consists of quotas in the aggregate amount of SFR 20,000, which are held by the
Sellers in the respective amounts set forth opposite their names on Schedule A.
                                                                    ----------
No share capital of the Company is held as treasury stock. The quotas of the
Company as of the date hereof are duly authorized, validly issued, fully paid
and nonassessable and not subject to preemptive rights created by statute, the
Charter Documents or any agreement to which the Company is a party or is bound.
The Company has not issued, nor is the Company or any Seller a party to or bound
by any option, warrant, call, right or agreement, obligating the Company to
issue, deliver or sell quotas or shares of capital stock of the Company,
including any agreement containing provisions with respect to preemptive rights,
rights of first refusal, purchase rights, "tag-along" or "come-along"
arrangements, or similar rights; any voting trust, proxy or other agreement or
understanding with respect to the voting of quotas or shares of capital stock of
the Company; and any other agreement restricting the transfer of, or affecting
rights with respect to, quotas or shares of the capital stock of the Company.

     Section 2.4 Investments; Related Companies.
                 ------------------------------

            (a)  The Company does not directly or indirectly own, or have the
right to acquire, any equity interest or investment in the equity capital of any
person or entity. The Company has no obligation to acquire any class of
securities (including debt securities) issued by any person or entity. The
Company has not owned or controlled any subsidiary corporation or any stock or
other interest in any person or entity and is not a party to, and has not been a
party to, or bound by any partnership, joint venture, voluntary association,
cooperative or business trust agreement or arrangement.

            (b)  The Related Company is a GmbH company organized under the laws
of Germany. The authorized share capital of the Related Company consists of
50,000 Deutschmarks, which is held by Mrs. Czenkusch-Hans. No share capital of
the Related Company is held as treasury stock. The share capital of the Related
Company as of the date hereof is duly authorized, validly issued, fully paid and
nonassessable and not subject to preemptive rights


                                       5
<PAGE>
 
created by statute, the organizational documents of the Related Company or any
agreement to which the Related Company is a party or is bound. The Related
Company has not issued, nor is the Related Company or any Seller a party to or
bound by any option, warrant, call, right or agreement, obligating the Related
Company to issue, deliver or sell quotas or shares of capital stock of the
Related Company, including any agreement containing provisions with respect to
preemptive rights, rights of first refusal, purchase rights, "tag-along" or
"come-along" arrangements, or similar rights; any voting trust, proxy or other
agreement or understanding with respect to the voting of quotas or shares of
capital stock of the Related Company; and any other agreement restricting the
transfer of, or affecting rights with respect to, quotas or shares of the
capital stock of the Related Company. The Company has delivered to the Purchaser
true and complete copies of the organizational documents of the Related Company,
as amended to date (the "Related Party Charter Documents"). Mrs. Czenkusch-Hans,
                         -------------------------------
as the sole shareholder of the Related Company, has authorized the dissolution
of the Related Company pursuant to German law and has appointed Ekkehard Hans as
the liquidator of the Related Company. Notice of such actions has been duly
recorded in the commercial register at Kempten/Allgau and was published three
times in the Federal Gazette as required by German law on or before February 4,
1998. True and complete copies of such notices and publications have been
provided to the Purchaser.

            (c)  The Related Company has no employees or operations (other than
the conduct, by Ekkehard Hans as liquidator, of the statutory liquidation of the
Related Company) nor does it have any material assets or any material
liabilities or obligations, whether absolute, accrued, contingent or otherwise,
of any nature other than as set forth in Section 2.4(c) of the Disclosure
                                                               ----------
Schedule. The Company has not assumed (expressly, by operation of law or
--------
otherwise), nor does the Company have any liability for, any obligations or
liabilities of the Related Company, or obligations or liabilities arising out of
the activities of the Related Company.

            (d)  The Related Company has not, since its inception, declared or
paid any dividends or redeemed or made any distribution in respect of its
capital stock nor has it made any payment or distribution to any Seller, other
than compensation, reasonable in amount, for services actually provided by such
Seller as to the Related Company and reimbursement of actual out-of-pocket
expenses paid by such Seller for the benefit of the Related Company.

     Section 2.5 Financial Statements.
                 --------------------

            (a)  The balance sheet of the Company at December 31, 1997 and the
related statement of income for the year then ended, together with the review
report thereon of Interrevision AG, the Company's independent accountants and
the balance sheet as of April 28, 1998 (the "Balance Sheet") and related income
                                             -------------
statement of the Company for the four months then ended, all of which are
included in Section 2.5 of the Disclosure Schedule (collectively, the "Financial
                               -------------------                     ---------
Statements"), comply with the Swiss Company Law and the articles of
----------
incorporation of the Company, have been prepared in accordance with
internationally accepted accounting standards and fairly present in all material
respects the financial condition and results of operation of the Company as of
the dates and for the periods specified.


                                       6
<PAGE>
 
            (b)  All accounts receivable reflected on the Balance Sheet and the
Company's books and records as of the date hereof represent sales actually made
in the ordinary course of business and in a manner consistent with the Company's
regular credit practices. The reserve for doubtful accounts reflected on the
Balance Sheet has been established based upon and consistent with past practice
and is adequate. All amounts reflected on the Balance Sheet as "Accounts
Receivable Clients" are collectible in full in accordance with the Company's
normal credit terms and, in any event, by September 30, 1998.

            (c)  The inventory of the Company reflected on the Balance Sheet
consists of merchandise and spare parts held for sale that are in new condition,
are included in the Company's current price list and are saleable in the
ordinary course of the Company's business. The inventory reserve reflected on
the Balance Sheet has been established based upon and consistent with past
practice and is adequate. Other than equipment held by customers for evaluation
purposes (reflected as "Goods for Sale Outside" in the Financial Statements),
all the Company's inventory is held at its premises at Grenzstrasse 24, St.
Margrethen, Switzerland. No inventory is held on consignment by or for the
Company.

            (d)  The loan receivable by the Company from Ekkehard Hans in the
amount of $76,698 (the "Hans Loan"), represents the valid, enforceable
obligation of Mr. Hans, and is collectible in full in accordance with its terms,
and, in any event, by September 30, 1998.

            (e)  The Company has no liabilities or obligations of any nature,
whether absolute, accrued, contingent or otherwise, other than those disclosed
or reflected on the Balance Sheet or disclosed in accordance with this Agreement
(including any Schedule hereto), those incurred since April 28, 1998 in the
ordinary course of the Company's business consistent with past practice, and
contingent liabilities or obligations that are not material, individually or in
the aggregate.

            (f)  The Company does not have any outstanding indebtedness for
borrowed money (which, for purposes of this paragraph, shall not be deemed to
include accounts payable arising out of the purchase of goods and services in
the ordinary course of the Company's business), other than as reflected on the
Balance Sheet.

     Section 2.6 Compliance with Applicable Laws. The Company holds all permits,
                 -------------------------------
licenses, variances, certificates of occupancy, exemptions, orders, approvals
and authorizations of all governmental authorities that are necessary for the
operation of its business (the "Permits"). The Company is in compliance with the
                                -------
terms of the Permits, except where any such failure so to comply, individually
or in the aggregate with any other such failures, would not have a Company
Material Adverse Effect. The business of the Company is not being conducted in
violation of or conflict with any law or governmental order, except such
violations or conflicts as do not and will not, individually or in the
aggregate, have a Company Material Adverse Effect. As of the date of this
Agreement, no investigation or review by any governmental authority with respect
to the


                                       7
<PAGE>
 
Company is pending or, to the knowledge of the Company or any Seller,
threatened, nor has any governmental authority indicated an intention to conduct
the same.

     Section 2.7 Litigation. There is no claim, dispute, action, suit, appeal,
                 ----------
legal, administrative or arbitral proceeding, or investigation, at law or in
equity, pending against the Company, or involving any of its assets or
properties, before any court, agency, authority, arbitration panel or other
tribunal, and, to the knowledge of the Company and each Seller, none has been
threatened. The Company is not subject to any subpoena, warrant, order, writ,
injunction or decree of any court, agency, authority, arbitration panel or other
tribunal, nor is it in default with respect to any such subpoena, warrant,
order, writ, injunction or decree. No judgment has been entered by, and no
claim, dispute, action, suit, appeal, legal, administrative or arbitral
proceeding, or investigation, at law or in equity, is pending or, to the
knowledge of the Company or any Seller, threatened, that materially and
adversely affects, or could materially and adversely affect, the ability of the
Company to perform under this Agreement or that seeks to enjoin or prohibit any
of the transactions contemplated by this Agreement.

     Section 2.8 Properties.
                 ----------

            (a)  Owned Properties. The Company does not own and has never owned
any real property (other than leasehold interests referred to in paragraph (b)
below).

            (b)  Leased Properties. The Company has delivered to Purchaser true
and complete copies of all leases, subleases, licenses, revocable use permits
and other agreements (collectively, the "Real Property Leases") under which the
                                         --------------------
Company uses or occupies any real property (the land and improvements covered by
the Real Property Leases being herein called the "Leased Real Property"). Each
Real Property Lease is valid, binding and in full force and effect, no written
notice of default or termination thereunder is outstanding with respect to any
Real Property Lease, all rent and other material sums due and payable by the
Company under each Real Property Lease are current, neither the Company nor, to
the knowledge of the Company, the lessor, is in default in any material respect
in its obligations under any Real Property Lease, and no event has occurred nor
condition exists which, with the giving of notice or the lapse of time or both,
would constitute a material default under any Real Property Lease.

            (c)  Personal Property. The Company has good and marketable title
to, or holds under valid leasehold estates, all personal property necessary for
the operation of the Company's business, free and clear of any imperfection of
title, lien or encumbrance.

            (d)  Condition of Property. The Leased Real Property and personal
property owned and leased by the Company and necessary for the operation of the
Company's business are in good operating condition and repair, ordinary wear and
tear excepted.

     Section 2.9 Contracts. As used herein, "Contracts" means all written or
                 ---------
oral agreements, contracts, instruments, guaranties, or commitments to which the
Company is a party


                                       8
<PAGE>
 
or by which or to which the Company's assets or properties are bound or subject.
The Company has provided or made available to Purchaser true and complete copies
of all of the following Contracts to which it is a party, a list of which
Contracts is attached as Section 2.9 of the Disclosure Schedule:
                                            -------------------

     (a)  Contracts with any current or former officer, director, employee,
          consultant, agent, representative or security holder, including any
          employment, consulting or deferred compensation agreement and any
          executive compensation, bonus or incentive plan agreement;

     (b)  Contracts for the purchase, sale or lease of materials, supplies,
          equipment, goods, research and development, or capital assets, or the
          receipt of services, the performance of which will extend over a
          period of more than one year or involve consideration in excess of
          $10,000;

     (c)  Contracts currently in effect that were entered into in the ordinary
          course of business and that involve payment of consideration to or by
          the Company in excess of $10,000 (other than purchase orders from
          customers received in the ordinary course of business);

     (d)  Contracts for the sale of any assets or properties of the Company
          other than in the ordinary course of business or for the grant to any
          Person of any preferential rights to purchase any assets or properties
          of the Company;

     (e)  Contracts establishing joint ventures or partnerships;

     (f)  Contracts establishing franchise, distribution or sales agency
          arrangements;

     (g)  Contracts under which the Company agrees to indemnify any party other
          than Contracts entered into in the ordinary course of business;

     (h)  Contracts containing obligations or liabilities of any kind to holders
          of the capital stock of the Company as such;

     (i)  Contracts relating to the acquisition by the Company of any operating
          business or any capital stock of any other Person;

     (j)  Contracts containing options for the purchase of any asset tangible or
          intangible, for an aggregate purchase price of more than $10,000;

     (k)  Contracts requiring the payment to any person of any override or
          similar commission or fee;


                                       9
<PAGE>
 
          (l)  Contracts for the borrowing of money;

          (m)  Contracts calling for an aggregate purchase price or payments by
               the Company in any one year of more than $20,000 in any one case
               (or in the aggregate, in the case of any related series of
               Contracts); and

          (n)  any other Contracts that were not made in the ordinary course of
               business and that are, individually or in the aggregate, material
               to the Company.

     Section 2.10 Taxes.
                  ----- 

          (a)  The Company has timely filed in accordance with applicable law
all Tax Returns (as defined below) required to be filed by or with respect to
it, its operations and assets. All Taxes (as defined below) shown as due on such
Tax Returns have been paid. All Tax Returns filed by the Company with respect to
Taxes were prepared in compliance with all applicable laws and regulations and
were true and complete in all material respects as of the date on which they
were filed or as subsequently amended to the date hereof. The Company has
provided or otherwise made available to Purchaser true and complete copies of
all Tax Returns of the Company for each of the years ended December 31, 1997 and
1996 and all revenue agent's reports and other written assertions of
deficiencies or other liabilities for Taxes with respect to past periods for
which the applicable statute of limitations has not expired. The Company will
provide to Purchaser copies of any such reports or written assertions received
after the date hereof within ten days of their first being received by the
Company.

          (b)  The Company has timely paid, or will timely pay on or prior to
the Closing Date, all Taxes for which a notice of, or assessment or demand for,
payment has been received or which are otherwise due and payable up to and
including the Closing Date with respect to the Company, its operations and
assets (in each case, whether or not shown on any Tax Return), except for Taxes
that are being contested in good faith by appropriate proceedings and Taxes for
which adequate reserves are reflected on the Balance Sheet.

          (c)  The Company has complied with all applicable laws, rules and
regulations relating to the withholding of Taxes and has timely collected or
withheld and paid over (and up to the Closing Date will have timely collected or
withheld and paid over) to the proper governmental authorities all amounts
required to be so collected or withheld and paid over for all periods up to the
Closing Date under all applicable laws. There are not currently in effect any
waivers or extensions of any applicable statute of limitations for the
assessment or collection of Taxes with respect to any Tax Return that relates to
the Company, and no request for any such waiver or extension is pending.

          (d)  The Company has no current or potential contractual obligation to
indemnify any other Person with respect to Taxes, and has no obligation to make
distributions in respect of Taxes. No claim has ever been made by a taxing
authority in a jurisdiction where the


                                       10
<PAGE>
 
Company does not file Tax Returns that the Company is or may be subject to
taxation by such jurisdiction. No power of attorney has been granted by the
Company with respect to any matter relating to Taxes, which power of attorney is
currently in force.

As used herein: "Taxes" means all taxes of any kind, charges, fees, customs,
duties, imposts, levies or other assessments, including all net income, gross
receipts, ad valorem, value added, transfer, gains, franchise, profits,
inventory, net worth, capital stock, asset, sales, use, license, estimated,
withholding, payroll, transaction, capital, employment, social security, workers
compensation, unemployment, excise, severance, stamp, occupation, and property
taxes, together with any interest and any penalties, additions to tax or
additional amounts, imposed by any taxing authority; and "Tax Return means all
returns, declarations, reports, forms, estimates, information returns and
statements required to be filed in respect of any Taxes or to be supplied to a
taxing authority in connection with any Taxes.

     Section 2.11 Benefit Plans.
                  -------------

          (a)  Except as set forth in the employment agreements listed in
Section 2.9 of the Disclosure Schedule and except for statutory benefits
                   -------------------
required by Swiss law to be provided to employees of the Company, there are no
employee benefit plans, arrangements, policies or commitments (including any
employment, consulting or deferred compensation agreement, executive
compensation, bonus, incentive, pension, profit-sharing, savings, retirement,
stock option, stock purchase or severance pay plan, any life, health, disability
or accident insurance plan, or any holiday or vacation practice) as to which the
Company has any direct or indirect, actual or contingent liability.

          (b)  The consummation of the transactions contemplated by this
Agreement will not entitle any current or former individual employed by the
Company to severance pay, unemployment compensation or any similar payment.

     Section 2.12 Absence of Certain Changes or Events. Except as contemplated
                  ------------------------------------
by this Agreement, since December 31, 1997, the Company has conducted its
business only in the ordinary course consistent with past practice. Without
limiting the generality of the foregoing, during such period:

          (a)  there has been no material adverse change in the business,
               results of operations, properties, assets, liabilities, prospects
               or condition (financial or otherwise) of the Company nor has
               there been any occurrence or circumstance that with the passage
               of time could reasonably be expected to result in such a change;

          (b)  neither the business, properties nor assets of the Company have
               suffered a material adverse loss (whether or not covered by
               insurance) as the result of fire, explosion, earthquake,
               accident, labor trouble, condemnation or taking


                                       11
<PAGE>
 
               of property by any Governmental Authority, flood, windstorm,
               pestilence, embargo, riot, act of God or the public enemy or any
               other casualty or similar event;

          (c)  The Company has not declared or paid any dividend or other
               distribution (whether in cash, stock or property or any
               combination thereof) in respect of the capital stock of the
               Company;

          (d)  The Company has not purchased, redeemed or otherwise acquired (or
               committed itself to purchase, redeem or acquire), directly or
               indirectly, any shares of the capital stock of the Company;

          (e)  The Company has not made any acquisition of all or any part of
               the assets, properties, capital stock or business of any other
               Person, other than inventory, equipment and supplies acquired in
               the ordinary course of business consistent with past practice;

          (f)  The Company has not, except in the ordinary course of business
               consistent with past practice, sold or otherwise disposed of any
               material assets of the Company;

          (g)  The Company has not sold, assigned, transferred, conveyed or
               licensed, or committed itself to sell, assign, transfer, convey
               or license, any Proprietary Rights (as defined in Section 2.20),
                                                                 ------------
               other than in the ordinary course of business;

          (h)  The Company has not waived or released any right or claim of
               material value to its business, including any write-off or other
               compromise of any material account receivable of the Company;

          (i)  The Company has not paid, directly or indirectly, any of its
               material liabilities before the same became due in accordance
               with its terms or otherwise than in the ordinary course of
               business consistent with past practice;

          (j)  The Company has not made any payment or commitment to pay any
               severance or termination pay to any employee of the Company;

          (k)  The Company has not made any wage or salary increase or bonus, or
               increase in any other direct or indirect compensation for or to
               any employee, officer, director, consultant, agent or other
               representative, other than in the ordinary course of business
               consistent with past practice;


                                       12
<PAGE>
 
          (l)  The Company has not made any loan or advance to any of its
               Stockholders, officers, directors, employees, consultants, agents
               or other representatives (other than travel advances made in the
               ordinary course of business), or made any other loan or advance
               otherwise than in the ordinary course of business consistent with
               past practice;

          (m)  The Company has not pledged or otherwise, voluntarily or
               involuntarily, encumbered any of its assets or properties, except
               for liens for current taxes which are not yet delinquent and
               purchase-money liens arising out of the purchase or sale of
               products made in the ordinary and usual course of business and in
               any event not in excess of $5,000 for any single item or $10,000
               in the aggregate;

          (n)  The Company has not materially changed any of its accounting
               methods, principles or procedures;

          (o)  The Company has not materially changed any of its business
               policies or practices, including advertising, marketing, pricing,
               purchasing, personnel, sales or budget policies;

          (p)  The Company has not suffered or incurred any damage, destruction
               or loss, whether or not covered by insurance, which will have or
               could reasonably be expected to have a Company Material Adverse
               Effect; and

          (q)  The Company has not entered into any agreement to do any of the
               foregoing.

     Section 2.13 Officers, Directors and Key Employees. The Company has
                  -------------------------------------
provided to Purchaser:

          (a)  the name, position held and compensation of each person who is
either an officer or director of the Company or an employee, consultant, agent
or other representative of the Company whose current annual rate of compensation
(including bonuses and commissions) exceeds $50,000;

          (b)  all wage and salary increases or bonuses received by any such
person since January 1, 1997, and any accrual by the Company for, or commitment
or agreement by the Company to pay, any wage or salary increase or bonus to any
such Person; and

          (c)  any arrangement or obligation of the Company to make any payment
to any such person as a result of, or conditioned on, the consummation of the
transactions contemplated hereby.


                                      13
<PAGE>
 
No Seller has reason to believe that any of the Persons described in clause (a)
above intends to terminate such Person's relationship with the Company.

     Section 2.14 Potential Conflicts of Interest. Except for normal
                  -------------------------------
compensation received as employees, no officer, director or stockholder of the
Company and no entity known by the Company to be controlled by any officer,
director or stockholder of the Company:

          (a)  is directly or indirectly engaged in business as a competitor,
lessor, lessee, customer or supplier of the Company; owns directly or indirectly
any interest (excepting no more than five percent stockholdings for investment
purposes in securities of publicly held companies) in any person that is engaged
in business as a competitor, lessor, lessee, franchisee, customer or supplier of
the Company; or is an officer, director, employee or consultant of any such
person;

          (b)  owns directly or indirectly, in whole or in part, any material
tangible or intangible property that the Company uses;

          (c)  has any cause of action or other claim whatsoever against, or
owes any amount to, the Company, except for claims in the ordinary course of
business, such as for accrued vacation pay, and similar matters in agreements
existing on the date hereof, or

          (d)  has made any payment or commitment to pay any commission, fee or
other amount to, or purchase or obtain or otherwise contract to purchase or
obtain any goods or services from, any person of which any officer or director
of the Company is a partner or stockholder (excepting no more than five percent
stockholdings for investment purposes in securities of publicly held companies).

     Section 2.15 Finder's Fees. The Company has not incurred any liability,
                  -------------
contingent or otherwise, for brokerage fees, finder's fees, agent's commissions,
financial advisory fees or other similar forms of compensation in connection
with this Agreement or any of the transactions contemplated hereby.

     Section 2.16 Bank Accounts. The Company has provided or made available to
                  -------------
Purchaser true and complete written summaries of information regarding all
accounts, lock boxes and safe deposit boxes maintained by the Company at banks,
trust companies, securities or other brokers or other financial institutions,
including the names of all persons authorized to draw thereon or have access
thereto.

     Section 2.17 Environmental Matters. The Company has been in the past and is
                  ---------------------
now in compliance with all environmental laws and all requirements of applicable
permits, licenses, approvals and other authorizations pertaining thereto other
than any such noncompliance that would not have a Company Material Adverse
Effect.


                                      14
<PAGE>
 
     Section 2.18 Insurance. The Company has delivered or made available to
                  ---------
Purchaser true and complete copies of all insurance policies or binders to which
the Company is a party or under which the Company is covered and true and
complete copies of all applications for insurance policies. All insurance
policies to which the Company is a party or that provide coverage to the Company
are in full force and effect. Since its formation, the Company has not received
any refusal of coverage, or any notice of suspension, revocation, modification
or cancellation or any other indication that any insurance policy is no longer
in full force or effect or that the issuer of any policy is not willing or able
to perform its obligations thereunder or any notice from an insured to
discontinue any coverage afforded to the Company and there is no basis for the
issuance of any such notice or the taking of any such action. The Company has
paid all premiums due and has otherwise performed all of its respective
obligations under each such policy, except such as will not adversely affect the
Company's coverage thereunder. There was no claim in excess of $5,000 asserted
under any of the insurance policies of the Company for the period from the
inception of the Company to the date hereof. The Company is not party to, or
bound by, any Contract requiring the Company to name a third party as loss payee
under any insurance policy or binder held by or on behalf of the Company or
otherwise requiring the Company to obtain insurance for or on behalf of any
third party or to provide coverage to third parties (such as, for example, under
leases or service agreements). There is no self-insurance arrangement by or
affecting the Company.

     Section 2.19 Employee Relations. The Company has never been a party to a
                  ------------------
collective bargaining agreement and has never made any final or binding offer to
a labor union or association representing its employees with respect to any
terms or conditions of employment. The Company has never had, nor is there now
threatened, a union organizing effort, strike, picket, organized work stoppage,
organized work slowdown, or other labor trouble that has had, or could
reasonably be expected to have, a Company Material Adverse Effect. The Company
has complied with all applicable laws relating to employment, equal opportunity,
nondiscrimination, immigration, wages, hours, benefits, collective bargaining,
the payment of social security and similar taxes, occupational safety and
health, and plant closings.

     Section 2.20 Proprietary Rights. The Company owns, or is licensed or
                  ------------------
otherwise possesses legally enforceable rights to use, all patents, trademarks,
trade names, service marks, copyrights, and any applications therefor,
technology, know-how, computer software programs or applications (in both source
code and object code form), and tangible or intangible proprietary information
or material that are material to the business of the Company as currently
conducted or as proposed to be conducted by the Company (the "Proprietary
                                                              -----------
Rights"). No claims with respect to the Proprietary Rights have been asserted
------
or, to the knowledge of the Company, are threatened by any person to the effect
that the business of the Company as currently conducted or as proposed to be
conducted by the Company, infringes on or misappropriates any copyright, patent,
trademark, service mark, trade secret or other proprietary rights of any other
Person or constitutes unfair competition or trade practices under any Law,
against the use by the Company of any trademarks, service marks, trade names,
trade secrets, copyrights, patents, technology, know-how or computer software
programs and applications used in the Company's business as


                                      15
<PAGE>
 
currently conducted or as proposed to be conducted by the Company, or
challenging the ownership by the Company, validity or effectiveness of any of
the Proprietary Rights.

     Section 2.21 Certain Loans. Other than the Hans Loan, there are no loans,
                  -------------
receivables, advances or similar amounts owed to the Company by any director,
officer, employee, consultant or stockholder of the Company, or owing by any
affiliate of any director or officer of the Company, nor is any amount owed by
the Company to any of its directors, officers, employees or stockholders other
than normal compensation and advances in the ordinary course of business to
officers and employees for reimbursable business expenses not exceeding $1,000
for any one individual.

     Section 2.22 Customers and Vendors. The Company has provided to PHI a true
                  ---------------------
and complete written summary listing of the ten largest customers and vendors of
the Company (by dollar volume of purchases) for the year ended December 31,
1997. The relationships of the Company with its customers and vendors are good
commercial working relationships, and no material customer or vendor of the
Company has canceled or otherwise terminated, or threatened in writing to cancel
or otherwise terminate, its relationship with the Company since January 1, 1997.

     Section 2.23 Business Activity Restrictions. There is no agreement
                  ------------------------------
(noncompetition or otherwise), commitment, judgment, injunction, order or decree
to which the Company or any officer, employee or consultant of the Company is a
party or that otherwise is binding upon the Company or such officer, employee or
consultant that has or reasonably could be expected to have the effect of
prohibiting or impairing any business practice of the Company, any acquisition
of property (tangible or intangible) by the Company or the conduct of business
by the Company. The Company has not entered into any agreement under which the
Company is restricted from selling, licensing or otherwise distributing any of
its technology or products to, or providing services to, customers or potential
customers or any class of customers, in any geographic area, during any period
of time or in any segment of the market or line of business.

                                  ARTICLE III
                        REPRESENTATIONS AND WARRANTIES
                                OF EACH SELLER

     As an inducement to the Purchaser to enter into this Agreement, each
Seller, severally but not jointly, represents and warrants to Parent and the
Purchaser as follows:

     Section 3.1 Authority. Such Seller has full power and authority to enter
                 ---------
into this Agreement, the Registration Rights Agreement, the Escrow Agreement and
such Seller's Affiliate Lock-Up Agreement (collectively, the "Seller
                                                              ------
Agreements") and the Seller Agreements are binding and enforceable against such
----------
Seller. All corporate action on the part of the Company, the Related Company,
and the Sellers necessary to authorize the execution, delivery and performance
of the Seller Agreements and transfer to the Purchaser of the Company Shares and
the Related


                                      16
<PAGE>
 
Company Shares has been duly taken. The execution, delivery and performance by
the Sellers of this Agreement will not result in any violation of or constitute
any breach under the Charter Documents or Related Company Charter Documents, any
provision of Swiss or German law, or any agreement to which the Company, the
Related Company or any Seller is a party or by which any of them is bound.

     Section 3.2 Ownership. Such Seller is the sole and exclusive record and
                 ---------
beneficial owner of all right, title and interest in and to the number of
Company Shares and Related Company Shares set forth opposite such Seller's name
on Schedule A hereto, free and clear of all claims and encumbrances of any
   ----------
nature whatsoever. Upon the execution and delivery by the Sellers to Purchaser
of the Company Transfer Documents and the publication and registration thereof
in the commercial register of the Kanton of St. Gallen, the Purchaser will be
the legal and beneficial owner of the Company Shares, free and clear of any
claims and encumbrance of any nature whatsoever. Upon the execution and delivery
to the Purchaser of the Related Company Transfer Documents and the publication
and registration thereof in the commercial register at Kempten/Allgau, the
Purchaser will be the legal and beneficial owner of the Related Company Shares,
free and clear of any claims and encumbrance of any nature whatsoever.

     Section 3.3 Further Assurances. Each Seller will execute and deliver to the
                 ------------------
Purchaser such additional documents and take such further action as may be
reasonably requested by the Purchaser in order to transfer ownership of and
title to all Company Shares and Related Company Shares being purchased from such
Seller to the Purchaser.

     Section 3.4 Investment in PRI Common.
                 ------------------------

            (a)  Such Seller (together with such Seller's financial and other
advisors, if any) has such knowledge and expertise in financial and business
matters that such Seller is capable of evaluating the merits and risks of the
exchange of such Seller's Company Shares and Related Company Shares for shares
of PRI Common pursuant to this Agreement and of protecting such Seller's
interests in connection therewith. Such Seller has the ability to bear the
economic risk of the investment in PRI Common.

            (b)  Such Seller has been provided with copies of Parent's Annual
Report on Form 10-K, as amended, for the fiscal year ended September 30, 1997,
and its Quarterly Reports on Form 10-Q for the fiscal quarters ended December
28, 1997 and March 29, 1998.

            (c)  Such Seller is acquiring shares of PRI Common for such Seller's
own account and not with a view to, or for resale in connection with, any
distribution thereof in violation of applicable law, and such Seller has no
present intention of selling, granting any participating in, or otherwise
distributing the same in violation of applicable law. Such Seller understands
that the shares of PRI Common to be received by such Seller pursuant to this
Agreement have not been registered under the Securities Act of 1933, as amended
(the "Securities Act"), by reason of a specific exemption from the registration
      --------------
provisions of the


                                      17
<PAGE>
 
Securities Act that depends upon, among other things, the bona fide nature of
such Seller's investment intent and the accuracy of such Seller's
representations, warranties and covenants as expressed herein. Such Seller
understands that the shares of PRI Common to be received by such Seller pursuant
to this Agreement are characterized as "restricted securities"' under the
Securities Act inasmuch as they are being acquired in a transaction not
involving a public offering and that under such laws and applicable regulations
such shares may be resold without registration under the Securities Act only in
certain limited circumstances. Such Seller acknowledges that the shares of PRI
Common must be held indefinitely unless subsequently registered under the
Securities Act (pursuant to the Registration Rights Agreement or otherwise) or
an exemption from such registration is available. Such Seller is aware of the
provisions of Rule 144 under the Securities Act which permit limited resale of
shares purchased in a private placement subject to the satisfaction of certain
conditions, including the existence of a public market for the shares, the
availability of certain current public information about the Company, the resale
occurring not less than two years after a party has purchased and paid for the
security to be sold, the sale being effected through a "broker's transaction or
in transactions directly with a "market maker" (as provided by Rule 144(f) under
the Securities Act) and the number of shares being sold during any three-month
period not exceeding specified limitations.

            (d)  It is understood that each certificate representing shares of
PRI Common received by such Seller pursuant to this Agreement shall bear a
legend substantially to the following effect (in addition to any legend required
under applicable state securities laws):

            "THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT
            OF 1933. THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR
            HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT
            WITH RESPECT TO THE SECURITIES UNDER SUCH ACT OR AN OPINION OF
            COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT
            REQUIRED."

     Section 3.5 Tax Matters. Each Seller acknowledges that he or she has been
                 -----------
advised by Parent and the Purchaser that the sale of Company Shares and Related
Company Shares contemplated by this Agreement could give rise to gain that would
be taxable for United States federal income tax purposes. Each Seller further
acknowledges that he or she has been encouraged to seek the advice of a
qualified tax adviser with respect to the tax consequences to him or her, under
the laws of the United States, Switzerland, and any other relevant jurisdiction,
of the transactions contemplated hereby. Each Seller represents and warrants
that such Seller has not, in entering into this Agreement, relied upon any
advice or representation of Parent, the Purchaser, its independent auditors or
counsel or any other person acting on behalf of Parent or the Purchaser
concerning such tax consequences.


                                      18
<PAGE>
 
                                  ARTICLE IV
                        REPRESENTATIONS AND WARRANTIES
                          OF PARENT AND THE PURCHASER

     As an inducement to each Seller to enter into this Agreement, Parent and
the Purchaser jointly and severally represent and warrant to each Seller as
follows:

     Section 4.1 Corporate Status. Each of Parent and the Purchaser is a
                 ----------------
corporation duly incorporated, validly existing and in good standing under the
laws of The Commonwealth of Massachusetts, with all necessary corporate power
and authority to enter into and perform its obligations under this Agreement and
under the Registration Rights Agreement and the Escrow Agreement, to the extent
that either is a party thereto.

     Section 4.2 Authority. This Agreement has been duly and validly authorized,
                 ---------
executed and delivered by Parent and the Purchaser and is binding on and
enforceable against Parent and the Purchaser in accordance with its terms. The
Registration Rights Agreement and the Escrow Agreement will be duly and validly
authorized, executed and delivered by Parent and the Purchaser, respectively,
and will be binding and enforceable against each of them, respectively, to the
extent it is a party thereto.

     Section 4.3 Investment Purpose. The Purchaser is acquiring the Company
                 ------------------
Shares and the Related Company Shares for its own account for investment and not
for or with a view to or for resale in connection with any distribution thereof
within the meaning of the Securities Act.

     Section 4.4 Capitalization. The authorized and outstanding capital stock of
                 --------------
Parent consists of 400,000 shares of preferred stock, $.01 par value, none of
which is issued and outstanding, and 50,000,000 shares of PRI Common, of which 
[          ] shares were issued and outstanding as of [          ]. All of the
outstanding shares of PRI Common are, and the shares of PRI Common when issued
and delivered to each Seller in accordance with this Agreement will be, duly
authorized, validly issued, fully paid and nonassessable and not subject to
preemptive rights created by statute, Parent's articles of organization or
bylaws, or any agreement to which Parent is a party or is bound. As of the date
of the Agreement, all outstanding shares of PRI Common are listed on the Nasdaq
Stock Market, and there are no proceedings to revoke or suspend such listing.

                                   ARTICLE V
                                INDEMNIFICATION

     Section 5.1 Agreement to Indemnify. The Sellers shall jointly and severally
                 ----------------------
(and without any right of contribution from or indemnification by the Company)
indemnify, defend and hold harmless Parent, the Purchaser and the affiliates,
officers, directors, employees, representatives and agents of each of them
(collectively, the "Indemnified Persons") against and in respect of any and all
                    -------------------
claims, costs, losses, expenses, liabilities or other damages,


                                      19
<PAGE>
 
including interest, penalties and reasonable attorneys' fees and disbursements
(collectively "Damages") by reason of or otherwise arising out of a breach by
               -------
Sellers or any Seller of a representation, warranty or covenant contained in
this Agreement. The amounts for which the Indemnified Persons may seek
indemnification under this Article 8 shall extend to, and as used herein the
term "Damages" shall include, reasonable attorneys' fees and disbursements,
reasonable accountants' fees, costs of litigation and other expenses incurred by
them in the defense of any claim asserted against them and any amounts paid in
settlement or compromise of any claim asserted against them to the extent that
the claim asserted is or would have been subject to the indemnification
provisions hereof. The indemnity under this Article 8 extends only to the net
amount of Damages sustained by the Indemnified Person after deducting therefrom
any amount that such Indemnified Person recovers as proceeds of insurance in
respect of such claim, net of any cost of collection, deductible, retroactive
premium adjustment, reimbursement obligation or other cost directly related to
the insurance claim for such claim.

     Section 5.2 Survival of Representations and Warranties. Except as otherwise
                 ------------------------------------------
set forth below, the representations and warranties of the Sellers in this
Agreement shall survive the Closing, and any investigation made by Parent or
Purchaser, for a period of one year after the Closing Date or, if sooner, until
the publication of audited financial statements of Parent for its first fiscal
year ending after the date hereof (the "Survival Period"). The representations
                                        ---------------
and warranties of Parent shall survive until the end of the Survival Period. The
covenants of any party shall survive the Closing in accordance with their terms.

     Section 5.3 Certain Limitations. The obligations of the Sellers with
                 -------------------
respect to indemnification pursuant to Section 5.1 above shall be subject to the
                                       -----------
following limitations:

            (a)  no indemnification shall be required to be made hereunder
unless the aggregate amount of claims for which indemnity is sought exceeds
$150,000, in which case indemnification shall be provided to the full extent of
such claims; and

            (b)  no claims for indemnity shall be made after the expiration of
the Survival Period.

     Section 5.4 Specific Representations. Notwithstanding the foregoing, the
                 ------------------------
representations and warranties of the Sellers in Section 2.4(b), 2.4(c), 2.4(d),
2.5(b), 2.5(c) and 2.5(d) above and in Sections 3.1 through 3.4 above (the
"Specific Representations") shall survive the Closing, and any investigation
made by Parent or Purchaser, for a period of three years after the Closing Date.
The limitations set forth in Sections 5.2 and 5.3 above shall not apply to
claims for indemnification arising out of any breach of the Specific
Representations.


                                      20
<PAGE>
 
                                  ARTICLE VI
                              GENERAL PROVISIONS

     Section 6.1 Expenses. Except as otherwise specified in this Agreement, all
                 --------
costs and expenses, including, without limitation, fees and disbursements of
counsel, financial advisors and accountants, incurred in connection with this
Agreement and the transactions contemplated hereby shall be paid by the party
incurring such costs and expenses, whether or not the Closing shall have
occurred.

     Section 6.2 Notices. All notices, requests, claims, demands and other
                 -------
communications hereunder shall be in writing and shall be deemed to have been
duly given or made (i) as of the date delivered if delivered personally, by
overnight courier or by facsimile, or (ii) on the third business day after being
mailed or sent, if mailed by registered or certified mail (postage prepaid,
return receipt requested) or sent by overnight courier, in any case addressed to
the respective parties at the following addresses or telecopier numbers (or at
such other address or telecopier number for a party as shall be specified in a
notice given in accordance with this Section 6.2):
                                     -----------

            (a)  if to a Seller, to the address set forth for such Seller on
                 Schedule A hereto;
                 ----------
            (b)  if to the Company:

                 Chiptronix Handling Systems GmbH 
                 Grenzstrasse 24 
                 CH-9430 St. Margrethen 
                 Switzerland
                 Fax: 41-0-71747/5529
                 Telephone:
                 Attn: Ekkehard D. Hans

                 with a copy to:

                 Ring & Green
                 1900 Avenue of the Stars, Suite 2300
                 Los Angeles, CA 90067
                 Fax: (310)556-1346
                 Telephone: (310) 201-0777
                 Attn: Robert A. Ring, Esq.


                                      21
<PAGE>
 
            (c)  if to the Parent or Purchaser:
 
                 Parent:
                 -------

                 PRI Automation, Inc.
                 800 Middlesex Turnpike
                 Billerica, MA 01821-3986
                 Fax: (978) 671-9430
                 Telephone: (978) 670-4270
                 Attention: Mitchell G. Tyson, President

                 Purchaser:
                 ---------

                 PRI Switzerland, Inc.
                 800 Middlesex Turnpike
                 Billerica, MA 01821-3986
                 Fax:(978) 671-9430
                 Telephone: (978) 670-4270
                 Attention: Stephen D. Allison, President

                 in either case, with a copy to:

                 Foley, Hoag & Eliot, LLP
                 One Post Office Square
                 Boston, MA 02019
                 Fax: (617) 832-7000
                 Telephone: (617) 832-1000
                 Attention: Robert L. Birnbaum, Esq.

     Section 6.3 Public Announcements. No party to this Agreement shall make, or
                 --------------------
cause to be made, any press release or public announcement or otherwise
communicate with any news media in respect of this Agreement or the transactions
contemplated hereby without the prior written consent of the other parties.

     Section 6.4 Headings. The descriptive headings contained in this Agreement
                 --------
are for convenience of reference only and shall not affect in any way the
meaning or interpretation of this Agreement

     Section 6.5 Severability. If any term or other provision of this Agreement
                 ------------
is invalid, illegal or incapable of being enforced by any law or public policy,
all other terms and provisions of this Agreement shall nevertheless remain in
full force and effect so long as the economic or legal substance of the
transactions contemplated hereby is not affected in any manner materially
adverse to any party. Upon such determination that any term or other provision
is invalid, illegal or


                                      22
<PAGE>
 
incapable of being enforced, the parties hereto shall negotiate in good faith to
modify this Agreement so as to effect the original intent of the parties as
closely as possible in an acceptable manner in order that the transactions
contemplated hereby are consummated as originally contemplated to the greatest
extent possible.

     Section 6.6  Entire Agreement. This Agreement constitutes the entire
                  ----------------
agreement of the parties hereto with respect to the subject matter hereof and
supersedes all prior agreements and undertakings, both written and oral, between
any Seller, Parent or the Purchaser with respect to the subject matter hereof.

     Section 6.7  Assignment. This Agreement may not be assigned by operation of
                  ----------
law or otherwise without the express written consent of each Seller, Parent or
the Purchaser (which consent may be granted or withheld in the sole discretion
of each such party); provided, however, that the Purchaser may assign this
Agreement to an affiliate of the Purchaser without the consent of any Seller;
provided further, however, that no such assignment by the Purchaser shall
relieve the Purchaser of its obligation to deliver to the Sellers the
consideration specified in Section 1.2 above.

     Section 6.8  No Third Party Beneficiaries. This Agreement shall be binding
                  ----------------------------
upon and inure solely to the benefit of the parties hereto and their permitted
assigns and nothing herein, express or implied, is intended to or shall confer
upon any other person any legal or equitable right, benefit or remedy of any
nature whatsoever under or by reason of this Agreement.

     Section 6.9  Amendment. This Agreement may not be amended or modified
                  ---------
except by an instrument in writing signed by, or on behalf of, each Seller,
Parent and the Purchaser.

     Section 6.10 Governing Law. This Agreement shall be governed by, and
                  -------------
construed and enforced in accordance with, the laws of The Commonwealth of
Massachusetts applicable to contracts executed in and to be performed entirely
within that state.

     Section 6.11 Counterparts. This Agreement may be executed in one or more
                  ------------
counterparts, and by the different parties hereto in separate counterparts, each
of which when executed shall be deemed to be an original but all of which taken
together shall constitute one and the same agreement.

     Section 6.12 Arbitration.
                  -----------

            (a)   Any dispute, controversy or claim arising in connection with
this Agreement, including any claim for indemnification pursuant to Section 5 of
this Agreement, shall be settled by expedited arbitration by a panel of three
arbitrators; except that, notwithstanding the foregoing, any dispute,
controversy or claim arising in connection with a breach of the confidentiality
provisions of this Agreement shall not be subject to arbitration pursuant to
this Section 6.12. The arbitration shall be held in Boston, Massachusetts and
shall be conducted by,


                                      23
<PAGE>
 
and in accordance with the rules of, a commercial arbitration service mutually
acceptable to the parties (it being agreed that the Boston, Massachusetts office
of JAMS/Endispute shall be deemed to be mutually acceptable for such purpose)
(the "Arbitrator"). The rules set forth in this Section 6.12 shall govern such
arbitration to the extent they conflict with the rules of the Arbitrator.

         (b) Upon written notice by a party to any other party of a request for
arbitration hereunder, Parent, Purchaser and the Sellers (acting through the
Sellers' Representative) shall designate the Arbitrator and select three
arbitrators employed by the Arbitrator within thirty days after the date of such
notice. If they are unable within said thirty-day period to agree upon an
Arbitrator, the Boston, Massachusetts office of JAMS/Endispute, shall be
designated as the Arbitrator and the Arbitrator shall designate the three
arbitrators pursuant to its rules. The arbitration shall be conducted in an
expeditious manner, the parties using their best efforts to cause the
arbitration to be completed within sixty days after selection of the Arbitrator.
In the arbitration, there shall be no discovery except as the arbitrators shall
permit following a determination by the arbitrators that the party seeking such
discovery has substantial demonstrable need. All other procedural matters shall
be within the discretion of the arbitrators. In the event a party fails to
comply with the procedures in any arbitration in a manner deemed material by the
arbitrators, the arbitrators shall fix a reasonable period of time for
compliance and, if the party does not comply within said period, a remedy deemed
just by the arbitrators, including an award of default, may be imposed.

         (c) The determination of the arbitrators by majority vote shall be
final and binding on the parties. The expense of the arbitration and all
expenses incurred by the parties with respect thereto (including reasonable
attorneys' fees and fees of experts shall be borne by the party not prevailing
in the arbitration, as determined by the arbitrators; provided, that pending the
award of the arbitrators, the fees and expenses of the Arbitrator shall be
advanced equally by Parent and the Purchaser, on the one hand, and the Sellers,
on the other. Judgment upon the award rendered by the arbitrators may be entered
in the U.S. District Court for the District of Massachusetts sitting in Boston,
Massachusetts.

                                      * * *

                                       24
<PAGE>
 
     IN WITNESS WHEREOF, each Seller has executed this Agreement in his or her
individual capacity and each of parent and the Purchaser has caused this
Agreement to be executed by its officer thereunto duly authorized as of the date
first written above. 

PARENT:                                      SELLERS:

PRI AUTOMATION, INC.

By: /s/ Stephen D. Allison                   /s/ Ekkehard D. Hans
   --------------------------------          ---------------------------------
   Name:  Stephen D. Allison                 Ekkehard D. Hans
   Title: Chief Financial Officer

                                                           *
                                             ---------------------------------
PURCHASER:                                   Kerstin Czenkusch-Hans

PRI SWITZERLAND, INC.
                                                           *
                                             ---------------------------------
                                             Jorg-Michael Hans
By: /s/ Stephen D. Allison
   --------------------------------
   Stephen D. Allison
   President                                 *By: /s/ Ekkehard D. Hans
                                                 -----------------------------
                                                 Ekkehard D. Hans
                                                 Attorney-in-Fact


                                       25
<PAGE>
 
List of Exhibits*:
-----------------

 Exhibits A and A-l:  Form of Company Transfer Documents
 Exhibit B:           Form of Related Company Transfer Document
 Exhibit C:           Form of Registration Rights Agreement
 Exhibit D:           Form of Escrow Agreement
 Exhibit E:           Form of Opinion of Sellers' Counsel
 Exhibit F:           Form of Employment Agreement
 Exhibit G:           Form of Affiliate Lock-Up Agreement
 Exhibit H:           Form of Promissory Note


List of Schedules*:
------------------

Schedule A:   Schedule of Sellers
Schedule B:   PRI Options

Disclosure Schedule:

         Section 2.4(c):  Assets and Liabilities of Related Company
         Section 2.5:     Financial Statement
         Section 2.9      List of Material Contracts


*The above referenced exhibits and schedules are omitted in accordance with
601(b2) of regulation S-K. Copies will be provided to the Commission upon
request.

                                       26