Document:

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                                                                   EXHIBIT 10.78

                                                                  MARCH 26, 2001

                           SALE AND PURCHASE AGREEMENT

                                  BY AND AMONG

                                   WCS, INC.,

                                       AND

                          WILLIAMS COMMUNICATIONS, LLC

                                       AND

                            TELUS COMMUNICATIONS INC.

                           DATED AS OF MARCH 26, 2001

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                                                     ARTICLE 1.
                                                    DEFINITIONS

         SECTION 1.1           CERTAIN DEFINED TERMS.............................................................1

                                                     ARTICLE 2.
                                                 PURCHASE AND SALE

         SECTION 2.1           PURCHASE AND SALE OF THE PURCHASED SHARES.........................................8

         SECTION 2.2           PURCHASE PRICE....................................................................8

         SECTION 2.3           CLOSING...........................................................................9

         SECTION 2.4           CLOSING DELIVERIES................................................................9

         SECTION 2.5           SALE OF ASSETS BY, DISTRIBUTIONS FROM AND CONTRIBUTIONS TO THE
                               CORPORATION PRIOR TO THE CLOSING DATE............................................11

         SECTION 2.6           SECTION 116 CERTIFICATE..........................................................11

         SECTION 2.7           ADJUSTMENT OF PURCHASER'S CLOSING PAYMENT........................................13

                                                     ARTICLE 3.
                            REPRESENTATIONS AND WARRANTIES OF SELLER AND THE CORPORATION

         SECTION 3.1           ORGANIZATION AND AUTHORITY.......................................................15

         SECTION 3.2           STATUS OF THE CORPORATION........................................................15

         SECTION 3.3           PURCHASED SHARES.................................................................16

         SECTION 3.4           SUBSIDIARIES.....................................................................16

         SECTION 3.5           NO CONFLICT......................................................................16

         SECTION 3.6           CONSENTS AND APPROVALS...........................................................16

         SECTION 3.7           FINANCIAL INFORMATION............................................................17

         SECTION 3.8           ABSENCE OF CERTAIN CHANGES, CONDITIONS AND EVENTS................................17

         SECTION 3.9           CONTRACTS........................................................................18

         SECTION 3.10          LITIGATION.......................................................................18

         SECTION 3.11          TAXES............................................................................18

         SECTION 3.12          LICENSES, PERMITS, AUTHORIZATIONS, ETC. .........................................19

         SECTION 3.13          EMPLOYEES AND EMPLOYEE BENEFIT MATTERS...........................................19

         SECTION 3.14          ENVIRONMENTAL MATTERS............................................................22

         SECTION 3.15          REAL PROPERTY....................................................................22

         SECTION 3.16          INSURANCE........................................................................22
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         SECTION 3.17          LEGAL COMPLIANCE.................................................................22

         SECTION 3.18          INTELLECTUAL PROPERTY............................................................23

         SECTION 3.19          BROKERS..........................................................................25

         SECTION 3.20          EXTENT OF REPRESENTATIONS AND WARRANTIES.........................................25

         SECTION 3.21          CERTIFICATES.....................................................................25

         SECTION 3.22          BOOKS AND RECORDS................................................................25

         SECTION 3.23          FULL DISCLOSURE..................................................................25

         SECTION 3.24          CNG..............................................................................25

                                                     ARTICLE 4.
                                  REPRESENTATIONS AND WARRANTIES OF THE PURCHASER

         SECTION 4.1           ORGANIZATION AND AUTHORITY.......................................................26

         SECTION 4.2           NO CONFLICT......................................................................26

         SECTION 4.3           CONSENTS AND APPROVALS...........................................................26

         SECTION 4.4           LITIGATION.......................................................................26

         SECTION 4.5           FINANCING........................................................................27

         SECTION 4.6           BROKERS..........................................................................27

         SECTION 4.7           EMPLOYEE BENEFITS................................................................27

                                                     ARTICLE 5.
                                        COVENANTS AND ADDITIONAL AGREEMENTS

         SECTION 5.1           CONDUCT OF BUSINESS PRIOR TO THE CLOSING.........................................27

         SECTION 5.2           ACCESS TO INFORMATION............................................................28

         SECTION 5.3           CONFIDENTIALITY..................................................................28

         SECTION 5.4           REGULATORY AND OTHER AUTHORIZATIONS AND CONSENTS.................................28

         SECTION 5.5           TAX MATTERS......................................................................29

         SECTION 5.6           NOTICE OF BREACHES...............................................................34

         SECTION 5.7           WILLIAMS MARKS...................................................................34

         SECTION 5.8           ENTERPRISE SOFTWARE..............................................................34

         SECTION 5.9           CROSS LICENSE AGREEMENT..........................................................35

         SECTION 5.10          TRANSITION SERVICES AGREEMENT....................................................36

         SECTION 5.11          DISTRIBUTION AGREEMENT...........................................................36

         SECTION 5.12          ASSETS TO BE PROVIDED BEFORE CLOSING.............................................36

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                                                     ARTICLE 6.
                                               CONDITIONS TO CLOSING

         SECTION 6.1           CONDITIONS TO OBLIGATIONS OF SELLER..............................................36

         SECTION 6.2           CONDITIONS TO OBLIGATIONS OF THE PURCHASER.......................................38

         SECTION 6.3           REASONABLE EFFORTS...............................................................39

         SECTION 6.4           NON-COMPETITION, CONFIDENTIALITY AND NON-SOLICITATION............................40

                                                     ARTICLE 7.
                                                  INDEMNIFICATION

         SECTION 7.1           SURVIVAL.........................................................................44

         SECTION 7.2           INDEMNIFICATION..................................................................44

         SECTION 7.3           TAX MATTERS......................................................................47

                                                     ARTICLE 8.
                                               TERMINATION AND WAIVER

         SECTION 8.1           TERMINATION......................................................................47

         SECTION 8.2           EFFECT OF TERMINATION............................................................48

         SECTION 8.3           WAIVER...........................................................................48

                                                     ARTICLE 9.
                                                   MISCELLANEOUS

         SECTION 9.1           EXPENSES.........................................................................48

         SECTION 9.2           NOTICES..........................................................................49

         SECTION 9.3           PUBLIC ANNOUNCEMENTS.............................................................49

         SECTION 9.4           HEADINGS.........................................................................50

         SECTION 9.5           SEVERABILITY.....................................................................50

         SECTION 9.6           ENTIRE AGREEMENT.................................................................50

         SECTION 9.7           ASSIGNMENT.......................................................................50

         SECTION 9.8           NO THIRD PARTY BENEFICIARIES.....................................................50

         SECTION 9.9           AMENDMENT........................................................................50

         SECTION 9.10          GOVERNING LAW....................................................................51

         SECTION 9.11          COUNTERPARTS.....................................................................51

         SECTION 9.12          FACSIMILE SIGNATURES.............................................................51

         SECTION 9.13          NO PRESUMPTION...................................................................51

         SECTION 9.14          RULES OF INTERPRETATION..........................................................51

         SECTION 9.15          SCHEDULES........................................................................52

         SECTION 9.16          FURTHER ASSURANCES...............................................................53
</Table>

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                           SALE AND PURCHASE AGREEMENT

         This SALE AND PURCHASE AGREEMENT (this "Agreement"), dated as of March
26, 2001, is made by and among:

                  WCS, INC., a Delaware corporation ("Seller"), and

                  WILLIAMS COMMUNICATIONS, LLC, a Delaware limited liability
                  company ("Seller's Parent"), and

                  TELUS COMMUNICATIONS INC., a Canadian corporation
                  ("Purchaser").

WITNESSETH:

         WHEREAS, Seller is the owner of sixteen (16) common shares of Williams
Communications Canada, Inc., a Canada corporation (the "Corporation"), which
represents all of the issued and outstanding shares in the capital of the
Corporation (the "Purchased Shares");

         WHEREAS, the Corporation has agreed to sell the CNG Business (as
defined in the Agreement) to Milgo Solutions Canada Company;

         WHEREAS, Seller desires to sell to Purchaser, and Purchaser desires to
purchase from Seller, the Purchased Shares, upon completion of the sale of the
CNG Business and upon the terms and subject to the conditions set forth herein;

         NOW, THEREFORE, in consideration of the premises and the mutual
agreements and covenants hereinafter set forth, the receipt and sufficiency of
which are hereby acknowledged, the parties hereto agree as follows:

                                   ARTICLE 1.
                                   DEFINITIONS

Section 1.1 CERTAIN DEFINED TERMS.

         As used in this Agreement, the following terms shall have the meanings
set forth below:

          "Accounts Payable" means all amounts in connection with the Business
due and owing by the Corporation to traders, suppliers and other persons in the
ordinary course of business.

         "Accounts Receivable" means any and all accounts receivable, bills
receivable, trade accounts, book debts and insurance claims recorded as
receivable in the Books and Records and any other amount due to the Corporation
including any refunds (other than refundable income taxes of Seller) and rebates
receivable in connection with the Business, and the benefit of all security
(including Cash deposits), guarantees and other collateral held by the
Corporation in connection with the Business.

         "Affiliate" has the meaning given in the Business Corporations Act
(Ontario), as amended from time to time.

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                                      -2-

         "Agreement" means this Sale and Purchase Agreement, including all
schedules, and all instruments supplementing or amending or confirming this
Agreement and references to "Article" or "Section" or "Schedule" mean or refer
to the specified Article, Section or Schedule to this Agreement.

         "Applicable Laws" means, in relation to any other person, transaction
or event, whether or not having the force of law, all applicable provisions of
laws, statutes, regulations, rules, guidelines, by-laws, treaties, orders,
policies, judgments, decrees and official directives of any Governmental Entity
or Person acting under the authority of a Governmental Entity.

         "Balance Sheet" has the meaning set forth in Section 3.7.

         "Benefit Plan(s)" has the meaning set forth in Section 3.13(b).

         "Books and Records" means all books and records of the Corporation,
including financial, corporate, operations and sales books, records, books of
account, sales and purchase records, lists of suppliers and customers, formulae,
business reports, plans and projections and all other documents, surveys, plans,
files, Tax Returns, correspondence, and other data and information, financial or
otherwise, including all data and information stored on computer-related or
other electronic media relating solely and exclusively to the Business.

         "Business" means the business of the Corporation as conducted as of the
date hereof excluding the CNG Business.

         "Business Day" means any day that is not a Saturday, a Sunday or other
day on which banks are required or authorized by law to be closed in Toronto,
Ontario.

         "Cash" means funds and/or monies held at the Corporation's financial
institutions, including deposit accounts, chequing accounts, payroll accounts,
investments in highly liquid securities, such as guaranteed investment
certificates, bankers' acceptances and treasury bills, and funds and/or monies
that are held at the Corporation's premises or are under the unrestricted
control of the Corporation net of any current bank indebtedness.

         "Claims" means all claims, demands, actions, suits, causes of action,
damages, losses, charges, judgements, debts, costs, liabilities or expenses,
including reasonable professional fees and all costs incurred in investigating
or pursuing any of the foregoing or any proceeding relating to any of the
foregoing.

         "Claim Notice" has the meaning set forth in Section 7.2(d).

         "Closing" has the meaning set forth in Section 2.3.

         "Closing Date" has the meaning set forth in Section 2.3.

         "Closing Date Financial Certificate" means the certificate delivered
pursuant to Section 2.4(a)(ii).

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                                      -3-

         "Closing Date Financial Statement" means the unaudited,
internally-prepared balance sheet of Corporation as at the Closing Date, showing
all of the assets and liabilities of the Corporation in connection with the
Business, after giving effect to the proposed disposition of CNG Business, and
the unaudited internally-prepared statement of income for the period January 1,
2001 to the Closing Date, also giving effect to the proposed disposition of CNG
Business, and a statement of the Net Working Capital as at the Closing Date.

         "CNG Assets" means the assets, property, agreements, commitments, other
contracts and liabilities which form the subject matter of the pro forma
financial balance sheet for the CNG Business Sale Agreement, the benefit and the
burden of the agreements listed in Schedule 2.5(a) and the Excluded Employees.

         "CNG Business" means the portion of the Corporation's business to be
sold to Milgo Solutions Canada Company pursuant to the CNG Business Sale
Agreement.

         "CNG Business Sale Agreement" means the Sale and Purchase Agreement
between the Corporation as vendor, Milgo Solutions Canada Company as purchaser,
and Seller's Parent, a copy of which is attached as Schedule 2.5(a).

         "Competition Act Approval" means (a) the issuance of an advance ruling
certificate pursuant to section 102 of the Competition Act by the Commissioner
of Competition appointed under the Competition Act (the "Commissioner") to the
effect that he is satisfied that he would not have sufficient grounds upon which
to apply to the Competition Tribunal for an order under section 92 of such Act
with respect to the transactions contemplated by this Agreement; or (b) that the
waiting period under section 123 of the Competition Act shall have expired and
(i) the Purchaser and the Seller shall have been advised in writing by the
Commissioner that the Commissioner has determined not to make an application for
an order under section 92 of the Competition Act in respect of the transactions
contemplated by this Agreement and that any terms and conditions attached to any
such advice shall be acceptable to the Purchaser and the Seller; and (ii) the
Commissioner shall not have made an application for an order under section 100
or section 104 of the Competition Act in respect of the transactions
contemplated by this Agreement.

         "Contest" has the meaning set forth in Section 5.5.3(b).

         "Contracts" means all contracts, arrangements, licenses, Leases,
understandings, purchase orders, invoices and other agreements, whether written
or oral, relating to the Business to which Seller or the Corporation is a party,
or by which Seller or the Corporation is bound.

         "Current Assets" includes all Accounts Receivable net of reserves,
costs in excess of billings, Inventories net of reserves, prepaid expenses and
other current assets of the Business generated in the ordinary course of
business, but excludes Cash and Deferred or Future Income Taxes.

         "Current Liabilities" includes all trade accounts payable, billings in
excess of cost and earnings, deferred maintenance revenue, Taxes payable and
accrued liabilities, including but not limited to, accruals for vacation pay,
customer rebates and allowances for product returns and

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                                      -4-

any other obligations of the Business incurred in the ordinary course of
business but excludes Deferred or Future Income Taxes.

         "Deferred or Future Income Taxes" means any income tax assets or
liabilities that arise on the temporary differences between the tax basis of an
asset or liability and its carrying value on the Corporation's Financial
Statements and Closing Date Financial Statements, as calculated in accordance
with GAAP.

         "Distributed Assets" means the assets, property, agreements,
commitments, other contracts and liabilities distributed from the Corporation to
the Seller pursuant to Section 2.5(b) and more particularly described on
Schedule 2.5(b).

         "Employees" means all employees, save and except the Excluded
Employees, of the Corporation as more particularly described in Schedule
3.13(c).

         "Encumbrances" means any pledge, lien, charge, security interest,
lease, title retention agreement, mortgage, restriction, development or similar
agreement, easement, right-of-way, title defect, option, adverse claim, right of
others or restriction (whether on voting, sale, transfer, disposition or
otherwise) or encumbrance whether imposed by agreement, understanding, law,
equity or otherwise against the assets of the Corporation of any kind or
character whatsoever.

         "Enterprise Software" means "off-the-shelf" or enterprise software
licensed from third parties that is used in or related to the Business and which
is set out in Schedule 5.8.

         "Excluded Assets" means the CNG Assets and the Distributed Assets.

         "Excluded Employees" means all employees or contract employees of the
Corporation who will be transferred to another company in connection with the
sale of the Excluded Assets as described on Schedule 2.5(a).

         "Financial Statements" means the unaudited, internally prepared balance
sheet of Corporation as at December 31, 2000 and the related statement of income
for the year then ended prepared, in the opinion of the Corporation's
management, in accordance with GAAP.

         "GAAP" means generally accepted accounting principles in Canada, as in
effect from time to time.

         "Governmental Entity" means any government or any agency, bureau,
board, commission, court, department, official, political subdivision, tribunal
or other instrumentality of any government, whether federal, provincial,
territorial or local, domestic or foreign, including without limitation the
Canada Customs and Revenue Agency.

         "Indemnified Party" has the meaning set forth in Section 7.2(d).

         "Indemnifying Party" has the meaning set forth in Section 7.2(d).

         "Independent Auditor" means PricewaterhouseCoopers.

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                                      -5-

         "Intellectual Property" means all the intellectual property of the
Corporation, other than that which are CNG Assets or Distribution Assets, and
all intellectual property necessary to carry on the Business as it is currently
being carried on by the Corporation as at the date hereof and will be all that
is required to carry on the Business as it is currently being carried on at the
Closing Date, including but not limited to:

         (a)      any and all inventions, improvements and discoveries, whether
                  or not reduced to practice and whether or not patentable or
                  made the subject of a patent application or applications;

         (b)      any invention disclosures, whether or not reduced to practice
                  and whether or not yet made the subject of a patent
                  application;

         (c)      national and multinational statutory invention registrations,
                  patents, patent registrations and patent applications
                  (including, without limitation, all reissues, divisions,
                  continuations, continuations in part, extensions and
                  reexaminations of the foregoing) and all rights therein
                  provided by international treaties or conventions and all
                  improvements to the inventions disclosed in each such
                  registration, patent or application;

         (d)      trademarks, service marks, logos and brand names, whether or
                  not registered, all applications and registrations including,
                  without limitation, all marks registered in the Canadian trade
                  mark office and all rights in the foregoing provided by
                  international treaties and conventions;

         (e)      copyrights (registered or otherwise) and registrations and
                  applications for registration thereof, and all rights therein
                  provided by international treaties or conventions;

         (f)      trade secrets and confidential, technical and business
                  information (including, without limitation, formulas,
                  compositions, inventions and conceptions of inventions whether
                  patentable or unpatentable and whether or not reduced to
                  practice);

         (g)      all rights to obtain and rights to apply for patents and
                  trademark and copyright registrations and all other
                  intellectual property registrations, whether currently
                  existing or which will arise in the future;

         (h)      any and all rights and benefits under any license arrangements
                  or agreements which the Corporation has with any Other Parties
                  whether express, implied or by reason of conduct or nature of
                  trade;

         (i)      any and all rights whether arising at law, in equity or by
                  course of conduct or under any agreement under which the
                  Corporation may make any claim or demand in relation to any
                  right, title or interest in any intellectual property or
                  related possessory or other proprietary right of any Other
                  Party;

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                                      -6-

         (j)      any and all rights to obtain injunctive relief for present and
                  past infringement of any intellectual property;

         (k)      any and all rights to any Encumbrances in or to or relating to
                  any intellectual property of any Other Party;

         (l)      any and all goodwill and reputation arising in or relating to
                  the intellectual property of the Corporation or the Business;

         (m)      any and all other intellectual property including industrial
                  designs and integrated circuit topographies;

and shall include, but not be limited to, any and all intellectual property and
any and all other proprietary rights and interests that may exist or arise in:

         (n)      the content of the Corporation's website located at
                  www.williamscommunications.com/canada including, web pages,
                  source code, interfaces, specifications, data, databases,
                  files, documentation and any and all other materials (the
                  Corporation shall change the same such that it does not have
                  the same look and feel as the www.williamscommunications.com
                  website) related thereto and already in existence; and

         (o)      source code, interfaces, specifications, data models, data,
                  databases, files, documentation and any and all other
                  materials relating to those items set forth in Schedule
                  3.18(a) and already in existence;

but shall exclude:

         (p)      the Williams Marks.

         "Inventories" means all inventories of every kind and nature and
wheresoever situate owned by the Corporation and pertaining to the Business
including all inventories of raw materials, work-in-progress, finished goods and
by-products, spare parts, operating supplies and packaging materials.

         "Knowledge of Seller" or any like phrase means the knowledge of
Seller's and/or the Seller's Parent's management after diligent inquiry into the
subject matter of the particular representation and/or warranty set out herein.

         "Leases" means all leases, subleases, licenses and other lease
agreements with respect to the Business, together with all amendments,
supplements and non-disturbance agreements pertaining thereto, under which the
Seller or the Corporation leases, subleases, licenses or uses any real or
personal property used in the conduct of the Business other than those which are
part of the Excluded Assets.

         "Loss" and "Losses" have the meanings set forth in Section 7.2(a).

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                                      -7-

         "Material Adverse Effect" means any change in, or effect on, the
Business that is materially adverse to the results, in isolation or in the
aggregate, of operations, financial condition or prospects of the Corporation.

         "Net Working Capital" means:

         (a)      the value of all Current Assets;

                  less

         (b)      the value of all Current Liabilities;

         the whole as determined in a manner consistent with the Corporation's
         Financial Statements and accounting principles reflected therein,
         consistently applied.

         "Other Party" means any Person other than the Purchaser and the
Corporation.

         "PEH" means Platinum Equity, LLC.

         "Permits" means all franchises, permits, licenses, qualifications,
rights-of-way, easements, municipal and other approvals, authorizations, orders,
consents and other rights from, and filings with, any Governmental Entity of any
jurisdiction that are necessary for the lawful conduct of the Business.

         "Person" means an individual, a corporation, partnership, limited
liability company, trust, unincorporated organization or a government or any
agency or political subdivision thereof.

         "Prime Interest Rate" means the annual rate of interest announced from
time to time by the Royal Bank of Canada as a reference rate then in effect for
determining interest rates on United States dollar commercial loans in Canada.

         "Pro Forma Financial Statements" means the unaudited,
internally-prepared pro forma balance sheet of Corporation as at December 31,
2000 and the related pro forma statement of income for the year then ended,
prepared, in the opinion of the Corporation's management, in accordance with
GAAP, giving pro forma effect to the proposed disposition of CNG Business.

         "Purchase Price" has the meaning set forth in Section 2.2.

         "Purchased Shares" has the meaning set forth in the recitals to this
Agreement.

         "Purchaser" has the meaning set forth in the preamble to this
Agreement.

         "Purchaser Indemnitees" means Purchaser, the Corporation, Purchaser's
Representatives and Purchaser's Affiliates, and each of such Affiliates'
Representatives and Affiliates.

         "Representative" means any officer, director, principal, parent,
partner, attorney, accountant, advisor, lender, agent, trustee, duly authorized
employee or other representative of a party.

<PAGE>   12

                                     -8-

         "Seller" has the meaning set forth in the preamble to this Agreement.

         "Seller Indemnitees" means Seller and Seller's Representatives and
Affiliates, and each of Seller's Affiliates' Representatives and Affiliates.

         "Seller's Parent" has the meaning set forth in the preamble to this
Agreement.

         "Tax Return" means any return, report, information return or other
similar document or statement (including any related or supporting information)
filed or required to be filed with or submitted to any Governmental Entity with
respect to Taxes, including, without limitation, any claim for refund, amended
return or declaration of estimated Taxes and all federal, provincial, municipal,
territorial, local and foreign returns, reports and similar statements.

         "Taxes" means all federal, provincial, municipal, territorial, foreign
or other taxes, imposts, withholdings, rates, levies, assessments, fees,
charges, dues, fines, interest or penalties lawfully levied, assessed or imposed
by any Governmental Entity, including, without limitation, all income, capital
gains, sales, withholding, excise, use, property, capital, goods and services,
business transfer, value added, employment, compensation, social security,
payroll, privilege, franchise, licence and school taxes and custom and import
duties and includes any transferee, secondary or joint liability with respect
thereto.

         "Third Party" means any Person other than the Purchaser and an
Affiliate of the Purchaser and the Seller and an Affiliate of the Seller.

         "Threshold" has the meaning set forth in Section 7.2(e).

         "Williams Marks" means any and all trade marks and service marks,
whether registered or common law, and trade names and associated good will,
slogans, domain names and other like property owned or used by the Corporation
or any Affiliate thereof in which the name "Williams" or any derivative or
variation thereof is used, including the Seller's logos and any derivatives and
variations thereof.

                                   ARTICLE 2.
                                PURCHASE AND SALE

Section 2.1 PURCHASE AND SALE OF THE PURCHASED SHARES.

         Subject to and upon the terms and conditions of this Agreement, Seller
agrees to sell, transfer, assign, convey and deliver to Purchaser, and Purchaser
agrees to purchase, acquire and accept from Seller, the Purchased Shares.

Section 2.2 PURCHASE PRICE.

         The aggregate purchase price (the "Purchase Price") to be paid by
Purchaser to Seller for the Purchased Shares shall be THIRTY THREE MILLION
Dollars ($33,000,000), subject to adjustments as provided in this Agreement.

<PAGE>   13
                                      -9-

Section 2.3 CLOSING.

         Subject to and upon the terms and conditions of this Agreement, the
sale and purchase of the Purchased Shares contemplated by this Agreement shall
take place at a closing (the "Closing") to be held at the offices of McCarthy
Tetrault, Suite 4700, Toronto Dominion Bank Tower, Toronto, Ontario on the later
of: (i) May 31, 2001, or (ii) the day which is five (5) Business Days following
receipt of the Competition Act Approval provided it is not later than July 31,
2001; at 10:00 a.m., Toronto time (the "Closing Time") or at such other time or
on such other date or at such other place as Seller and Purchaser may mutually
agree upon in writing (the day on which the Closing takes place being the
"Closing Date").

Section 2.4 CLOSING DELIVERIES.

         (a)      At Closing, the Seller will tender and cause and procure to be
                  tendered:

                  (i)      a certificate signed by an officer of each of the
                           Seller and the Seller's Parent as to the accuracy as
                           of the Closing Date of the representations and
                           warranties of the Seller set forth in Article 3
                           hereof and the fulfillment at Closing of the
                           covenants of the Seller set forth in Article 5
                           hereof;

                  (ii)     a certificate signed by an officer of the Corporation
                           and the Seller as to the financial condition of the
                           Corporation on the Closing Date (the "Closing Date
                           Financial Certificate"), which certificate shall
                           include Financial Statements together with unaudited,
                           internally-prepared pro forma balance sheet of the
                           Corporation as at the Closing Date and the related
                           pro forma statements of income to the Closing Date,
                           giving effect to the proposed disposition of the CNG
                           Business, describing, in detail, all changes from the
                           December 31, 2000 unaudited financial statements;

                  (iii)    resignations in writing of all of the directors and
                           officers of the Corporation, in their capacity as
                           directors and officers of the Corporation and not as
                           Employees, unless otherwise directed by Purchaser;

                  (iv)     certified copies of resolutions of the directors of
                           the Corporation authorizing the transfer of the
                           Purchased Shares and the registration of the
                           Purchased Shares in the name of the Purchaser and
                           authorizing the issuance of new share certificates
                           representing the Purchased Shares in the name of the
                           Purchaser;

                  (v)      the Books and Records of the Corporation;

                  (vi)     every common seal of the Corporation;

                  (vii)    share certificates in the name of the Seller
                           representing the Purchased Shares duly endorsed for
                           transfer and duly executed share certificates in the
                           name of the Purchaser representing the Purchased
                           Shares;

<PAGE>   14
                                      -10-

                  (viii)   a certificate from an officer of each of the Seller
                           and the Seller's Parent that the CNG Business has
                           been sold pursuant to the CNG Business Sale Agreement
                           and all filings and remittances have been made by the
                           Corporation;

                  (ix)     an opinion reasonably satisfactory to the Purchaser
                           from Messrs. McCarthy Tetrault, solicitors for the
                           Seller and the Seller's parent, as to the validity of
                           the incorporation of the Corporation, as to the good
                           standing of the Corporation, as to the number of
                           issued, the validity of the issue, full payment and
                           non-assessability of the outstanding shares in the
                           capital of the Corporation, as to the validity of the
                           sale and transfer to the Purchaser of the Purchased
                           Shares and as to all other legal matters of a like
                           nature pertaining to the Corporation and to the
                           transactions provided for in this Agreement as the
                           Purchaser may reasonably require;

                  (x)      an opinion reasonably satisfactory to the Purchaser
                           from Messrs. McCarthy Tetrault, solicitors for the
                           Seller and the Seller's parent, as to the
                           enforceability of the Agreement on the Seller and the
                           Seller's Parent;

                  (xi)     copies of all Schedules updated and accurate to the
                           Closing Date;

                  (xii)    executed copies of all agreements required to be
                           delivered by the Seller pursuant to this Agreement,
                           including without limitation, the Ancillary
                           Agreements and the Canadian Customer Agreement.

         (b)      At the Closing, Purchaser shall tender and cause and procure
                  to be tendered:

                  (i)      subject to any withholding under Section 2.6, the
                           Purchase Price, such payment to be made by wire
                           transfer in immediately available funds to Seller's
                           account (which account shall be designated in writing
                           by Seller to Purchaser at least two Business Days
                           prior to the Closing Date);

                  (ii)     an opinion reasonably satisfactory to the Seller from
                           Messrs. Bennett Jones, solicitors for the Purchaser,
                           as to the validity of the incorporation of the
                           Purchaser, as to the good standing of the Purchaser,
                           as to the validity of the sale and transfer to the
                           Purchaser of the Purchased Shares, as to the
                           enforceability of the Agreement on the Purchaser and
                           as to all other legal matters of a like nature
                           pertaining to the Purchaser and to the transactions
                           provided for in this Agreement as the Seller may
                           reasonably require; and

                  (iii)    executed copies of all agreements required to be
                           delivered by the Purchaser pursuant to this
                           Agreement, including without limitation, the
                           Ancillary Agreements.

<PAGE>   15
                                      -11-

Section 2.5 SALE OF ASSETS BY, DISTRIBUTIONS FROM AND CONTRIBUTIONS TO THE
            CORPORATION PRIOR TO THE CLOSING DATE.

         (a)      Prior to the Closing Date, the Seller shall cause the
                  Corporation to complete the sale of the undertakings,
                  property, agreements, commitments, contracts and liabilities
                  of the CNG Business as contemplated in the CNG Business Sale
                  Agreement and more particularly described on Schedule 2.5(a).

         (b)      Prior to the Closing Date, the Seller shall cause the
                  Corporation to distribute to Seller the Distributed Assets
                  more particularly described on Schedule 2.5(b).

         (c)      Purchaser specifically acknowledges and consents to the
                  distributions contemplated by this Section 2.5 and such
                  distributions do not constitute a breach under this Agreement.

         (d)      Seller shall contribute to the Corporation or shall cause one
                  or more of its Affiliates to contribute to the Corporation,
                  the assets listed on Schedule 2.5(d) at no cost or expense to
                  the Corporation (such assets are collectively referred to as
                  the "Additional Assets").

         (e)      All distributions of Distributed Assets, contributions of
                  Additional Assets and other transfers of assets contemplated
                  hereby shall be effected by a form of assignment and
                  assumption agreement in form and substance mutually acceptable
                  to the parties hereto pursuant to which the transferees of the
                  assets being assigned shall assume the obligations,
                  liabilities, commitments and responsibilities related thereto
                  except as specifically agreed to the contrary.

         (f)      By written assignment to Seller's Parent, the Corporation
                  shall transfer all Williams Marks to The Williams Companies,
                  Inc. ("TWC") or its nominee.

Section 2.6 SECTION 116 CERTIFICATE.

         (a)      Seller shall on or before the Closing Date, deliver to the
                  Purchaser a certificate issued by the Minister of National
                  Revenue of Canada pursuant to subsection 116(2) of the Income
                  Tax Act (Canada) (a "Section 116 Certificate") in respect of
                  the proposed disposition by Seller of the Purchased Shares.
                  The Section 116 Certificate delivered by Seller shall specify
                  a "certificate limit" in an amount not less than the Purchase
                  Price.

         (b)      In the event that the Section 116 Certificate required under
                  Section 2.6(a) has not been delivered by Seller on or before
                  the Closing Date, or in the event that a Section 116
                  Certificate contains a "certificate limit" that is less than
                  the Purchase Price, the Purchaser shall withhold from the
                  Purchase Price an amount equal to 33 1/3% of the Purchase
                  Price, or, if a Section 116 Certificate has been delivered by
                  Seller, an amount equal to 33 1/3% of the amount by which the
                  Purchase Price exceeds the "certificate" limit specified in
                  the Section 116 Certificate (the "Withheld Amount"). The
                  Withheld Amount shall be paid over to the Purchaser's counsel
                  pursuant to an irrevocable direction of the Purchaser for

<PAGE>   16
                                      -12-

                  deposit in an interest bearing trust account at a bank located
                  in Ontario to be held for the benefit of Seller to be disposed
                  of as set out herein. The Withheld Amount shall be remitted by
                  the Purchaser's counsel to the Receiver General of Canada on
                  the day that the Withheld Amount is required to be so remitted
                  pursuant to subsection 116(5) of the Income Tax Act (Canada)
                  (the "Remittance Date"). All interest earned on the Withheld
                  Amount shall be for the account of Seller and the full amount
                  of such interest less any Taxes required to be withheld from
                  such interest shall be paid by the Purchaser's counsel to the
                  Seller on the Remittance Date.

         (c)      Notwithstanding the foregoing, if Seller delivers a Section
                  116 Certificate to the Purchaser's counsel at any time after
                  the Closing Date and prior to the day that is two Business
                  Days before the Remittance Date that exonerates the Purchaser
                  from liability under Section 116 of the Income Tax Act
                  (Canada) in respect of any payment on account of the Purchase
                  Price up to the amount of the "certificate limit" specified in
                  such Section 116 Certificate, Purchaser's counsel shall pay to
                  the Seller on account of the Purchase Price an amount equal to
                  the amount, if any, by which

                  (i)      the aggregate of

                           (A)      the Withheld Amount; and

                           (B)      the amount, if any, by which

                                    (A)      the amount of interest received by
                                             Purchaser's counsel on the Withheld
                                             Amount

                                             exceeds

                                    (B)      the amount of any Taxes payable by
                                             the Purchaser in respect of any
                                             interest on the Withheld Amount or
                                             which the Purchaser is required to
                                             withhold or deduct in respect of
                                             such interest

                           exceeds

                  (ii)     33 1/3% of the amount, if any, by which

                           (A)      the Purchase Price

                  exceeds

                           (B)      the "certificate limit" specified in the
                                    Section 116 Certificate.

         (d)      The parties agree that any upward adjustments in the Purchase
                  Price after Closing under this Agreement which result in the
                  adjusted Purchase Price being in excess of the certificate
                  limit set out in any Section 116 Certificate previously
                  delivered

<PAGE>   17
                                      -13-

                  by Seller in accordance with this Section 2.6 shall result in
                  additional withholding obligations in accordance with Section
                  2.6(b).

Section 2.7 ADJUSTMENT OF PURCHASER'S CLOSING PAYMENT.

         (a)      Purchaser's Closing Payment shall be adjusted to the extent
                  that the Net Working Capital of Corporation as of the Closing
                  Date differs from the target amount of Net Working Capital of
                  Corporation set forth in Schedule 2.7 hereof (the "Target
                  Amount"), as determined pursuant to and as provided in
                  Schedule 2.7. The amount of such adjustment, if any, shall be
                  referred to as the "Net Working Capital Adjustment." For the
                  purposes of calculating the adjustment pursuant to this
                  Section 2.7, any conversion of funds from Canadian dollars to
                  U.S. dollars shall be made at the exchange rate of 1.49779
                  Canadian dollars for every U.S. dollar.

         (b)      No later than five (5) Business Days prior to the Closing
                  Date, Seller shall prepare and deliver to Purchaser, a written
                  estimate of the Net Working Capital of Corporation as of the
                  Closing Date (the "Estimated Net Working Capital"), signed by
                  the chief financial officer of Seller, who shall certify that
                  such estimate was prepared on a consistent basis as the Target
                  Amount in good faith from the books and records of Corporation
                  and represents his or her best estimate of the Net Working
                  Capital of Corporation as of the Closing Date. Purchaser shall
                  review such written estimate and the parties shall resolve in
                  good faith any disagreements concerning such estimate no later
                  than two (2) Business Days prior to the Closing Date. To the
                  extent that the Estimated Net Working Capital of Corporation
                  is less than the Target Amount, Purchaser's Closing Payment
                  shall be reduced by the amount of such difference. To the
                  extent that the Estimated Net Working Capital of Corporation
                  is greater than the Target Amount, Purchaser's Closing Payment
                  shall be increased by the amount of such difference, such
                  increase not to exceed $5,000,000.

         (c)      No later than sixty (60) days following the Closing Date,
                  Purchaser shall prepare and deliver to Seller a final
                  statement of the Net Working Capital of Corporation as of the
                  Closing Date. Seller shall have sixty (60) days from receipt
                  of such statement of the Net Working Capital of Corporation as
                  of the Closing Date, (the "Review Period") to review such
                  statement. If as a result of such review, Seller disagrees
                  with Purchaser's final statement of the Net Working Capital of
                  Corporation as of the Closing Date, Seller shall deliver to
                  Purchaser a written notice of disagreement (a "Dispute
                  Notice") prior to the expiration of the Review Period, setting
                  forth the basis for such dispute in reasonable detail. If
                  Seller does not deliver a Dispute Notice within such Review
                  Period, then the Net Working Capital of Corporation as of the
                  Closing Date as shown on Purchaser's statement shall be final
                  and binding on Seller and Purchaser and shall provide the
                  basis for computing the amount of the Net Working Capital
                  Adjustment.

         (d)      If Seller delivers a Dispute Notice to Purchaser in a timely
                  manner, then Seller and Purchaser shall attempt in good faith
                  to resolve such dispute within thirty (30)

<PAGE>   18
                                      -14-

                  days from the date of such Dispute Notice. If Seller and
                  Purchaser cannot reach agreement within such thirty (30) day
                  period, then the dispute shall be promptly referred to the
                  Independent Auditor for binding resolution. The Independent
                  Auditor shall resolve such dispute as promptly as may be
                  reasonably practicable and shall endeavor to complete such
                  process within a period of no more than sixty (60) days. The
                  Independent Auditor may conduct such proceedings as the
                  Independent Auditor may determine, in its sole discretion,
                  will assist in the resolution of the dispute and shall deliver
                  a written opinion setting forth a final determination of the
                  Net Working Capital of Corporation as of the Closing Date
                  calculated in accordance with the provisions of this
                  Agreement. The determination of the Independent Auditor shall
                  be final and binding on Seller and Purchaser and shall be used
                  in computing the amount of the Net Working Capital Adjustment.
                  Sellers, on the one hand, and Purchaser, on the other hand,
                  shall each be responsible for fifty percent (50%) of the costs
                  and expenses of the Independent Auditor and Seller and
                  Purchaser shall each bear their own legal, accounting and
                  other fees and expenses of participating in such dispute
                  resolution procedure.

         (e)      If, pursuant to clause (c) or (d) of this Section 2.7, it is
                  finally determined that the Net Working Capital of Corporation
                  as of the Closing Date was less than the Estimated Net Working
                  Capital, then the Seller shall, within five (5) Business Days
                  from the date of such final determination, pay to Purchaser
                  the difference between the Net Working Capital as of the
                  Closing Date and the Estimated Net Working Capital, together
                  with interest thereon at the Prime Interest Rate from the
                  Closing Date to the date of payment, such cash payment to be
                  made by wire transfer of immediately available funds to such
                  bank account as Purchaser may designate (or, in the absence of
                  any such designation, by corporate check mailed to Purchaser).

         (f)      If, pursuant to clause (c) or (d) of this Section 2.7, it is
                  finally determined that the Net Working Capital of Corporation
                  as of the Closing Date was greater than the Estimated Net
                  Working Capital, then the Purchaser shall pay to the Seller
                  the difference between the Net Working Capital at Closing and
                  the Estimated Net Working Capital. For greater certainty, the
                  difference between the Net Working Capital at Closing and the
                  Estimated Net Working Capital plus the amount paid pursuant to
                  Section 2.7 (b) above shall not exceed $5,000,000 or (ii) if
                  the Net Working Capital as of the Closing Date is less than
                  the Estimated Net Working Capital, then the Seller shall pay
                  to the Purchaser an amount such that the total net amount paid
                  by the Purchaser under Section 2.7 is equal to the difference
                  between the Net Working Capital as of Closing and the Target
                  Amount, such difference not to exceed $5,000,000. All payments
                  hereunder shall be made within five (5) Business Days from the
                  date of such final determination, together with interest
                  thereon at the Prime Interest Rate from the Closing Date to
                  the date of payment, such cash payment to be made by wire
                  transfer of immediately available funds to such bank account
                  as Purchaser or Seller, as the case may be, may designate (or,
                  in the absence of any such designation, by corporate check
                  mailed to Purchaser or Seller, as the case may be).

<PAGE>   19
                                      -15-

         (g)      The Purchaser will pay at Closing to the Seller an amount
                  equal to the Cash balance on the Closing Date Financial
                  Statement, up to a maximum of $5,000,000. In no event shall
                  the Purchase Price exceed $38,000,000.

         (h)      The amounts payable by the Purchaser under Section 2.7 (b) or
                  Section 2.7 (f) shall be reduced by the amount paid under
                  Section 2.7 (g). For greater certainty, the amounts paid by
                  the Purchaser under Section 2.7 (g) plus the amounts paid
                  under either Section 2.7 (b) or Section 2.7 (f) shall not
                  exceed $5,000,000.

         (i)      To the extent that the Cash balance on the Closing Date
                  Financial Statements exceed $5,000,000 and the Net Working
                  Capital as at the Closing Date is less than the Target Amount,
                  then the amount of Cash in excess of $5,000,000 will be added
                  to the Net Working Capital as of the Closing Date for the
                  purposes of Sections 2.7 (e) and (f).

                                   ARTICLE 3.
          REPRESENTATIONS AND WARRANTIES OF SELLER AND THE CORPORATION

         Seller and the Seller's Parent, jointly and severally, hereby represent
and warrant to Purchaser as follows:

Section 3.1 ORGANIZATION AND AUTHORITY.

         Seller and the Corporation are each corporations, duly organized,
validly existing and in good standing under the laws of Delaware and Canada,
respectively. Seller has all necessary power and authority to enter into this
Agreement and to carry out its respective obligations hereunder and to
consummate the transactions contemplated hereby. The execution and delivery by
Seller of this Agreement, the performance by Seller and by the Corporation of
each of its respective obligations hereunder, and the consummation by Seller and
by the Corporation of the transactions contemplated hereby have been duly
authorized by all requisite action on the part of Seller and the Corporation.
This Agreement has been duly executed and delivered by Seller and the
Corporation and (assuming due authorization, execution and delivery by
Purchaser) constitutes a legal, valid and binding obligation of Seller,
enforceable against Seller and the Corporation in accordance with its terms
except as enforcement may be limited by bankruptcy, insolvency, reorganization,
or similar laws affecting the enforcement of creditors' rights generally and the
fact that equitable remedies such as specific performance and injunction, may
only be granted in the discretion of the court.

Section 3.2 STATUS OF THE CORPORATION.

         The Corporation has all necessary power and authority to own, operate
or lease the properties and assets now owned, operated or leased by it and to
carry on its Business as now conducted. The Corporation is qualified to do
business as an extra-provincial or foreign corporation in all jurisdictions in
which the nature of the business conducted or the properties and assets owned,
leased or operated, requires such qualification except to the extent that the
failure to be so qualified in any jurisdiction has not caused or is not
reasonably expected to have a Material Adverse Effect.

<PAGE>   20
                                      -16-

Section 3.3 PURCHASED SHARES

         The Purchased Shares constitute all of the issued and outstanding
ownership interests of the Corporation. The Purchased Shares have been duly and
validly issued and are fully paid and non-assessable. No options, warrants,
conversion or other rights, agreements or commitments of any kind obligating the
Corporation, contingently or otherwise, to issue or sell any ownership interests
in the Corporation of any class, or any securities convertible into or
exchangeable for any such ownership interests, are outstanding, and no
authorization therefor has been given. Seller owns the Purchased Shares free and
clear of all Encumbrances except for any Encumbrances arising out of, under or
in connection with this Agreement.

Section 3.4 SUBSIDIARIES.

         The Corporation does not have any subsidiaries or own any interest in
any other entity.

Section 3.5 NO CONFLICT.

         Except as otherwise set forth in Schedule 3.5, the execution, delivery
and performance by Seller, the Seller's Parent and the Corporation of this
Agreement do not and will not (a) conflict with or violate any provision of the
respective charter documents of Seller, the Seller's Parent or the Corporation
or of any subscription, shareholders' or similar agreement or understanding to
which Seller, the Seller's Parent or the Corporation is a party or by which any
of them is bound; (b) constitute or result in a breach of, or a default (or an
event which, with notice or lapse of time or both would constitute a default)
under, or result in the termination of, or accelerate the performance required
by, or create a right of termination or acceleration under, any note, bond,
mortgage or indenture, contract, agreement, lease, sublease, license, permit,
franchise or other instrument or arrangement relating to the Seller's, the
Seller's Parent or the Corporation's assets or properties and to which the
Seller, the Seller's Parent or the Corporation is a party except to the extent
that such breach, default, right of termination or acceleration has not caused
or is not reasonably expected to have a Material Adverse Effect; (c) constitute
a material violation by either Seller, Seller's Parent or the Corporation of any
applicable law or Permit; (d) constitute a violation by either Seller, the
Seller's Parent or the Corporation of any order, judgment, writ, injunction
decree or award to which it is a party or by which it is bound or affected
except to the extent that such violation has not caused or is not reasonably
expected to have a Material Adverse Effect or (e) result in the imposition of an
Encumbrance on any assets or properties of the Corporation or the Purchased
Shares.

Section 3.6 CONSENTS AND APPROVALS.

         The execution, delivery and performance of this Agreement by Seller
does not and will not require any consent, approval, authorization or other
order of, action by, filing with or notification to any Governmental Entity
except (a) as described in Schedule 3.6, (b) the notification requirements of
the Competition Act (Canada), (c) where failure to obtain such consent,
approval, authorization or action, or to make such filing or notification, would
not prevent Seller from performing any of Seller's obligations under this
Agreement and has not caused or is not reasonably expected to have a Material
Adverse Effect, and (d) as may be necessary as a result of any facts or
circumstances relating solely to Purchaser. If a consent or

<PAGE>   21
                                      -17-

approval is required due to subsection (c) above, Seller shall promptly inform
Purchaser and shall cooperate with Purchaser to attain the required consent or
approval.

Section 3.7 FINANCIAL INFORMATION.

         The Corporation has delivered to Purchaser the following financial
statements of the Corporation (collectively, the "Financial Information"): (i)
the unaudited financial statements for the year ended December 31, 1999, (ii)
the Financial Statements for the year ended December 31, 2000, and (iii) Pro
Forma Financial Statements as of and for the year ended December 31, 2000. The
Financial Statements and Pro Forma Financial Statements are set forth in
Schedule 3.7(a). Except as set forth in Schedule 3.7(b) or as otherwise
disclosed in this Agreement, the Financial Information were, in the opinion of
the Corporation's management, prepared in accordance with GAAP, consistently
applied, and fairly present in all material respects the financial condition and
results of operations of the Corporation as of such dates or for the periods
covered thereby. Except as set forth in the Financial Statements or as otherwise
disclosed in this Agreement, the Corporation does not have any material
liabilities or obligations (absolute, accrued, contingent or otherwise) other
than (i) immaterial liabilities or obligations not required to be included in
the Financial Information under GAAP in the reasonable opinion of the
Corporation's management, and (ii) liabilities incurred since the date of the
Balance Sheet in the ordinary course of business. Seller makes no representation
or warranty with respect to any projections, forecasts, business plans or
budgets provided to Purchaser in connection with their evaluation of the
purchase of the Purchased Shares.

Section 3.8 ABSENCE OF CERTAIN CHANGES, CONDITIONS AND EVENTS.

         Except as set forth in Schedule 3.8 or as otherwise disclosed in this
Agreement, since December 31, 2000, there has been no event, occurrence, fact,
condition, change, or effect that has caused or is reasonably expected to make
any representation in this Agreement inaccurate or has not caused or is not
reasonably expected to have a Material Adverse Effect and, without limiting the
generality of the foregoing:

         (a)      no dividends or other distribution of any kind have been
                  declared or paid by the Corporation;

         (b)      no capital expenditures or commitments have been made by the
                  Corporation in the aggregate in excess of $350,000;

         (c)      the Corporation has carried on the Business in the ordinary
                  course in a prudent, businesslike and efficient manner and
                  substantially in accordance with the procedures and practice
                  in effect on the date of the Financial Statements;

         (d)      there has been no material adverse change in the financial
                  position of the Corporation and no damage, loss or destruction
                  materially affecting the Business or the property of the
                  Corporation and its right or capacity to carry on business;

         (e)      except as reflected in Schedule 3.13(c) the Corporation has
                  not paid or agreed to pay any compensation, pension, bonus,
                  share of profits or other benefit to, or for the benefit of,
                  any employee, director, or officer of the Corporation except
                  in the

<PAGE>   22
                                      -18-

                  normal course of business and as of the date of such Schedule
                  3.13(c) has not increased the compensation paid or payable to
                  any director, officer and senior management employee;

         (f)      the Corporation has not waived or surrendered any right except
                  to the extent that such waiver or surrender has not caused or
                  is not reasonably expected to have a Material Adverse Effect;

         (g)      the Corporation has not settled any accounts receivable at
                  materially less than face value net of reserve for that
                  account; and

         (h)      the Corporation has not discharged or satisfied any
                  Encumbrance or paid any obligation or liability of any of the
                  Corporation other than the current liabilities in the ordinary
                  course of business.

Section 3.9 CONTRACTS.

         Schedule 3.9 sets forth a complete list of all customer contracts
contributing in excess of Cdn$500,000 in revenues for 2000 or likely to
contribute in excess of Cdn$500,000 in revenues for 2001 and all Corporation
obligations in excess of Cdn$250,000 to which the Corporation is a party or by
which the Corporation is bound and all (i) credit agreements, pledge agreements
and security agreements; (ii) agreements or commitments to make capital
expenditures; (iii) agreements to sell, lease or otherwise dispose of any
material assets or properties other than in the ordinary course of business;
(iv) agreements limiting the freedom of the Corporation to compete in any line
of business or in any geographic area or with any person; (v) Leases; and (vi)
joint venture agreements, development agreements and partnership agreements.
Except as disclosed on Schedule 3.9, the Corporation is not in default under any
contract, agreement, indenture, mortgage, lease, insurance policy or other
instrument to which it is a party or by which its properties or assets may be
bound or subject except to the extent that such default has not caused or is not
reasonably expected to have a Material Adverse Effect. The entire interest of
the Corporation under each of the Contracts is held by it free and clear of any
Encumbrances other than those which are the subject matter of the applicable
Contract itself.

Section 3.10 LITIGATION.

         Except as disclosed in Schedule 3.10, to the Knowledge of the Seller
there are no claims, actions, proceedings or investigations pending or
threatened against the Corporation which seek to have a Material Adverse Effect
on the Corporation or which seek to delay or prevent the consummation of, or
which would adversely affect Seller's ability to consummate the transactions
contemplated by this Agreement.

Section 3.11 TAXES.

         Except as set forth in Schedule 3.11,

         (a)      the Corporation has timely filed or will timely file all Tax
                  Returns required to be filed by it in respect of all Taxes for
                  any taxation period or portion thereof ending on or before the
                  Closing Date, all such Tax Returns are complete and correct,
                  and

<PAGE>   23
                                      -19-

                  no adjustment relating to such Tax Returns has been proposed
                  formally or informally by any Governmental Entity and no basis
                  exists for any such adjustments;

         (b)      all Taxes due and payable by the Corporation on or before the
                  Closing Date, including, without limitation, all Taxes that
                  the Corporation is required to withhold or collect, have been
                  paid or remitted to the proper Governmental Entity on a timely
                  basis;

         (c)      all Taxes that the Corporation is required to withhold or
                  collect on or before the Closing Date which are not due or
                  payable until after the Closing Date have been withheld and
                  collected;

         (d)      the Corporation is not a party to any action by any
                  Governmental Entity and no claim has been asserted, threatened
                  or proposed against it for assessment or collection of any
                  Taxes;

         (e)      the Corporation has not executed or filed with any
                  Governmental Entity any agreement extending the period of
                  assessment or collection of any Taxes; and

         (f)      there are no outstanding rulings, requests for rulings, or
                  other elections, designations, waivers, consents or agreements
                  with any Governmental Entity in respect of Taxes that are, or
                  if issued, would be, binding on the Corporation or which would
                  have an impact on the Corporation's Taxes for any future
                  taxation periods or for completed taxation periods for which
                  Tax Returns have not yet been filed.

Section 3.12 LICENSES, PERMITS, AUTHORIZATIONS, ETC.

         The Corporation has all Permits, licenses, approvals and other
authorizations of Governmental Entities necessary to operate the Business except
to the extent that the failure to obtain such Permits, licenses, approvals of
other authorizations of Governmental Authorities has not caused or is not
reasonably expected to have a Material Adverse Effect.

Section 3.13 EMPLOYEES AND EMPLOYEE BENEFIT MATTERS.

         (a)      Except as prohibited by Applicable Laws, there are no
                  agreements for the employment of any Employees that cannot be
                  terminated on reasonable notice, other than those described in
                  Schedule 3.13(a).

         (b)      There are no agreements for the payment of any bonus, deferred
                  compensation, incentive compensation, savings, pension, profit
                  sharing, retirement allowance, share purchase, share option,
                  severance or termination pay (other than as required by
                  statute), vacation pay (other than as required by statute),
                  insurance, hospitalization or any other benefits for any of
                  the Employees (the "Benefit Plans") in addition to salaries,
                  wages or commissions other than as described in Schedule
                  3.13(b).

<PAGE>   24
                                      -20-

         (c)      Schedule 3.13(c) shows all of the names, positions, starting
                  dates and base compensation of the Employees, other than the
                  Excluded Employees, and is accurate up to February 28, 2001.

         (d)      Without limiting the generality of Section 3.17 of this
                  Agreement, the Corporation is in compliance with all
                  applicable labour and employment related statutes in Canada,
                  except to the extent that the failure to be in compliance with
                  all applicable labour and employment related statutes in
                  Canada has not caused or is not reasonably expected to have a
                  Material Adverse Effect.

         (e)      No promises or commitments have been made by the Corporation
                  to amend any Benefit Plan or to provide increased benefits
                  thereunder to any Employee, except as required by Applicable
                  Laws and except to the extent that such promises to amend any
                  Benefit Plan or to provide any increased benefits has not
                  caused or is not reasonably expected to have a Material
                  Adverse Effect.

         (f)      Except as disclosed on Schedule 3.13(f), all of the Benefit
                  Plans are, and have been since their establishment, duly
                  registered where required by legislation (including
                  registration with the relevant tax authorities where such
                  registration is required to qualify for tax exemption or other
                  beneficial tax status) and are in good standing under, and are
                  in compliance with, all Applicable Laws and administrative
                  guidelines issued by the regulatory authorities except to the
                  extent that such non-compliance, failure to register or
                  failure to be in good standing has not caused or is not
                  reasonably expected to have a Material Adverse Effect.

         (g)      Except as permitted by the Benefit Plans and Applicable Laws,
                  there has been no withdrawal of any amounts from any of the
                  Benefit Plans other than proper payments of benefits to
                  eligible beneficiaries, refunds of over-contributions to plan
                  members and permitted payments of reasonable expenses incurred
                  by or in respect of such Benefit Plan.

         (h)      All Benefit Plans have been administered in accordance with
                  their terms, there are no outstanding defaults or violations
                  by the Corporation of any obligation required to be performed
                  by it in connection with any Benefit Plan and no order has
                  been made or notice given pursuant to any Applicable Laws
                  requiring (or proposing to require) the Corporation to take
                  (or refrain from taking) any action in respect of any Benefit
                  Plan, except to the extent that such failure to administer the
                  Benefit Plans in accordance with their terms or such defaults
                  or violations of obligations or such orders or notices given
                  have not caused, or are not reasonably expected to have, a
                  Material Adverse Effect.

         (i)      All employer and, if applicable, employee contributions under
                  the Benefit Plans have been remitted in a timely manner (other
                  than current contributions not in arrears) and the Benefit
                  Plans have been funded in accordance with their terms and any
                  generally accepted actuarial principles and practices which
                  are applicable.

<PAGE>   25
                                      -21-

         (j)      To the Knowledge of the Seller, all returns, filings, reports
                  and disclosures relating to the Benefit Plans required
                  pursuant to the terms of the Benefit Plans, Applicable Laws or
                  any regulatory authority, have been filed or distributed in
                  accordance with all requirements, all filing fees and levies
                  imposed on the Benefit Plans by the regulatory authorities or
                  Applicable Laws have been made on a timely basis and the funds
                  of the Benefit Plans are not exposed to any late filing fees
                  that have not been remitted.

         (k)      To the Knowledge of the Seller, there are no actions, suits,
                  claims, trials, demands, arbitrations, investigations or
                  proceedings pending or threatened with respect to the Benefit
                  Plans against the Corporation, the funding agent, the insurers
                  or the fund of such Benefit Plans, other than claims for
                  benefits in the ordinary course or as disclosed in writing by
                  the Seller to the Purchaser, which seek to have a Material
                  Adverse Effect on the Corporation or other proceedings pending
                  or threatened.

         (l)      The Corporation has never provided a defined benefit
                  registered or unregistered pension plan to its Employees or
                  the Excluded Employees.

         (m)      No event has occurred and there has been no failure to act on
                  the part of the Corporation, any funding agent or any
                  administrator of any of the Benefit Plans that could subject
                  the Corporation or the fund of any Benefit Plan to the
                  imposition of any tax, penalty or other disability with
                  respect to any Benefit Plans, whether by way of indemnity or
                  otherwise except to the extent that any of such taxes, penalty
                  or other disability has not caused or is not reasonably
                  expected to have a Material Adverse Effect.

         (n)      The contribution obligations, if any, of the Corporation to
                  any of the Benefit Plans that are multi-employer pension plans
                  or multi-employer benefit plans are accurately set out in
                  Schedule 3.13(b).

         (o)      Neither the execution, delivery or performance of this
                  Agreement, nor the consummation of any of the other
                  transactions contemplated by this Agreement, will result in
                  any bonus, golden parachute, severance or other payment or
                  obligation by or of the Corporation to any current or former
                  employee or director of the Corporation (whether or not under
                  any Benefit Plan), or materially increase the benefits payable
                  or provided under any Benefit Plan provided by the
                  Corporation, or result in any acceleration of the time of
                  payment or vesting of any such benefits.

         (p)      Except as set forth in Schedule 3.13(p), there are no
                  independent contractor arrangements.

         (q)      There are no independent contractor arrangements, whether
                  written or oral, under which Applicable Laws would require any
                  such independent contractor to be re-classified as an
                  Employee.

<PAGE>   26
                                      -22-

         (r)      There are no union Employees and neither the Corporation nor
                  the Seller are aware of any initiatives to unionize any of the
                  Employees.

Section 3.14 ENVIRONMENTAL MATTERS.

         The Corporation is in compliance in all respects with all federal,
provincial, state, local and other statutes, ordinances, rules and regulations
relating to the environment or to the protection of public health, except to the
extent that the failure to be in compliance with all applicable federal,
provincial, state, local and other statutes, ordinances, rules and regulations
relating to the environment or to the protection of public health has not caused
or is not reasonably expected to have a Material Adverse Effect. Except as
disclosed in Schedule 3.14 and in this Section 3.14, there are no facts,
circumstances, or conditions that directly or indirectly related to the assets
owned, leased by or otherwise in control of the Corporation or the past or
present conduct of the Business with respect to environmental, health or safety
matters that have existed or now exist and already have had or may have a
Material Adverse Effect on the operation of the Business or use of the assets
owned, leased by or otherwise in control of the Corporation or that may give
rise to any liability on the Purchaser or the Corporation concerning the
protection, preservation or remediation of the natural environment, whether air,
land, surface water or groundwater.

Section 3.15 REAL PROPERTY.

         The Corporation does not own any real property that is used in the
Business. Schedule 3.15 sets forth a complete and correct list of all real
property used in the Business that is subject to any Lease, and the business
terms of such Lease including rent, maturity date and square footage of the
premises leased thereunder, and that is not part of the Excluded Assets. All of
the Leases are in good standing and there is no condition or circumstance which
could result in an event of default under such Leases.

Section 3.16 INSURANCE.

         Schedule 3.16 contains a general description of all current policies of
insurance maintained with respect to the Corporation and the Business, and
contains a general description of the current policies and the coverage thereof.
Except for health insurance and other insurance carried or maintained in
connection with providing benefits under Benefit Plans, all of such insurance
has been maintained by Seller or its parent companies and will terminate with
respect to the Corporation and its operations as of the Closing.

Section 3.17 LEGAL COMPLIANCE.

         The conduct and operations of the Business are in compliance with each
applicable law of any Governmental Entity except to the extent that the failure
to be in compliance with each applicable law of any Governmental Authority has
not caused or is not reasonably expected to have a Material Adverse Effect.

<PAGE>   27
                                      -23-

Section 3.18 INTELLECTUAL PROPERTY.

         (a)      The Intellectual Property is all the intellectual property
                  necessary to carry on the Business as currently being carried
                  on by the Corporation as at the date hereof and will be all
                  that is required to carry on the Business, as currently being
                  carried on, as at the Closing Date;

         (b)      the Corporation has good and valid legal and beneficial title
                  to and/or right to use all of the Intellectual Property
                  (except Enterprise Software), free and clear of any
                  Encumbrances of any nature;

         (c)      the Seller and Corporation have no knowledge or information of
                  any facts which would affect the validity, enforceability,
                  scope or registrability of any of the Intellectual Property;

         (d)      to the knowledge of the Seller and to the knowledge of the
                  Corporation all patent, trademark and copyright registrations
                  in the Intellectual Property are valid, subsisting and
                  enforceable, and such patents, registered trademarks and
                  registered copyrights are duly recorded in the name of the
                  Corporation, with the exception of the three (3) TTS
                  trademarks, and the Corporation and Seller has no knowledge of
                  any reason as to why the same cannot be recorded in the name
                  of the Purchaser;

         (e)      To the Knowledge of Seller and to the knowledge of the
                  corporation all statements contained in all applications for
                  registration of the Intellectual Property were correct and
                  complete as of the date of such applications and are still
                  true;

         (f)      the Corporation has, and after the Closing will have, the sole
                  and exclusive ownership and right, free from any claims or
                  demands or Encumbrances to fully use and exploit the
                  Intellectual Property to the full extent of the rights granted
                  in intellectual property and the consummation of the
                  transactions contemplated hereby will not alter or impair any
                  such rights;

         (g)      no material claims have been asserted by any Other Party with
                  respect to, or challenging or questioning, the ownership,
                  validity, enforceability or use of the Intellectual Property
                  and the Corporation and Seller have no knowledge of any valid
                  basis for any such claim;

         (h)      to the Knowledge of the Seller, the Corporation has not
                  received any notice, complaint, threat, claim or demand
                  alleging infringement of and the conduct by the Corporation of
                  the Business and the use by the Corporation of the
                  Intellectual Property does not infringe any patent, trademark,
                  trade name, trade secret, domain name, obligation of
                  confidence or other proprietary, contract or intellectual
                  property right of any Other Party except to the extent that
                  such infringement has not caused or is not reasonably expected
                  to have a Material Adverse Effect.;

         (i)      To the knowledge of the Seller and Corporation no Other Party
                  is infringing the rights of the Corporation with respect to
                  the Intellectual Property;

<PAGE>   28
                                      -24-

         (j)      the Corporation has not received any notice, information,
                  threat, claim or demand suggesting that it does not own all
                  right, title and interest in the Intellectual Property or that
                  the Corporation does not have the sole and exclusive right to
                  exploit the Intellectual Property in any manner whatsoever;

         (k)      Except as set forth in Schedule 3.18(k), complete and correct
                  copies of all material agreements relating to or affecting the
                  Intellectual Property have been provided to the Purchaser and
                  no such agreements contains a provision relating to a change
                  of control;

         (l)      The Corporation owns all Intellectual Property in its own name
                  except for Enterprise Software and Software subject to the
                  Cross License Agreement, in which case the Intellectual
                  Property has been licensed from a Other Party;

         (m)      no royalty, payment or other fee is required to be paid by the
                  Corporation to any Other Party in respect of the use or any
                  other exploitation of any of the Intellectual Property except
                  as set out in the agreements listed on Schedule 3.18(m) and
                  except as required to maintain or renew the applications and
                  registrations;

         (n)      the Corporation is not in breach of any agreement under which
                  it acquires or has acquired any right or interest in any
                  Intellectual Property;

         (o)      the Intellectual Property is used exclusively in connection
                  with the Business of and is not used in a manner likely to
                  cause confusion in the marketplace;

         (p)      all trade secrets used by the Corporation are the unencumbered
                  property of the Corporation, do not infringe upon the rights
                  of any third party, were developed by the Corporation and its
                  respective employees with appropriate secrecy and ownership
                  safeguards and have been maintained by the Corporation in
                  strict confidence and no such trade secrets have been
                  disclosed directly or indirectly to any Other Party;

         (q)      all confidential information of any Other Party held by the
                  Corporation under any obligations of confidentiality has been
                  kept strictly confidential and not used, disclosed,
                  disseminated or published unless otherwise permitted pursuant
                  to such agreement;

         (r)      the Corporation and no Other Party with whom the Corporation
                  has an agreement relating to any Intellectual Property or any
                  intellectual property of such Other Party are in breach of
                  such an agreement or will be as a result of the Corporation
                  entering this Agreement; and

         (s)      Notwithstanding the foregoing, no representation or warranty
                  is made that the Corporation will obtain any rights in the
                  Enterprise Software or that the Enterprise Software can be
                  transferred to the Corporation.

<PAGE>   29
                                      -25-

Section 3.19 BROKERS.

         Except as to The Blackstone Group, whose fees and expenses are payable
by Seller, no broker, finder or investment banker is entitled to any brokerage,
finder's or other fee or commission in connection with the transactions
contemplated by this Agreement based upon arrangements made by or on behalf of
Seller, the Corporation or a Subsidiary.

Section 3.20 EXTENT OF REPRESENTATIONS AND WARRANTIES.

         The Seller makes no representations or warranties to the Purchaser
except as specifically set forth in this Article 3 and this Agreement contains
all representations and warranties of the Seller relating to the transactions
contemplated hereby. All disclosure contained in a particular representation and
warranty set forth in this Agreement (or any Schedule referred to therein) shall
be deemed for the purposes of this Agreement to have been made with respect to
all of the representations and warranties in this Article 3 to which such
disclosure might be applicable.

Section 3.21 CERTIFICATES.

         All certificates of the Seller and the Corporation delivered to the
Purchaser and its representatives pursuant to this Agreement and the information
contained in each such certificate will be deemed to be part of the
representations and warranties of the Sellers and the Corporation contained in
this Article 3.

Section 3.22 BOOKS AND RECORDS.

         Seller has made available to the Purchaser all Books and Records of the
Corporation. Such Books and Records fairly and correctly set out and disclose in
all material respects the financial position of the Business and all financial
transactions relating to the Business have been accurately recorded in such
Books and Records.

Section 3.23 FULL DISCLOSURE.

         All information, which has been provided to the Purchaser relating to
the Business is true and correct in all material respects and no material fact
or facts have been omitted therefrom which would make such information
misleading.

Section 3.24 CNG

         None of the CNG Assets have been used by the Corporation to carry on
its customer premise telecommunications equipment sales, procurement,
installation, support and maintenance business as it is currently being carried
on.

<PAGE>   30
                                      -26-

                                   ARTICLE 4.
                 REPRESENTATIONS AND WARRANTIES OF THE PURCHASER

         The Purchaser hereby represents and warrants to Seller as follows:

Section 4.1 ORGANIZATION AND AUTHORITY.

         The Purchaser is a corporation duly organized, validly existing and in
good standing under the laws of Canada and has all necessary power and authority
to enter into this Agreement, to carry out its obligations hereunder and
thereunder, and to consummate the transactions contemplated hereby. The
execution and delivery by the Purchaser of this Agreement, its performance of
its obligations hereunder, and its consummation of the transactions contemplated
hereby have been duly authorized by all requisite action on the part of the
Purchaser. This Agreement has been duly executed and delivered by the Purchaser
and (assuming due authorization, execution and delivery by Seller) this
Agreement constitutes a legal, valid and binding obligation of the Purchaser,
enforceable against Purchaser in accordance with its terms except as enforcement
may be limited by bankruptcy, insolvency, reorganization, or similar laws
affecting the enforcement of creditors' rights generally and the fact that
equitable remedies such as specific performance and injunction, may only be
granted in the discretion of the court.

Section 4.2 NO CONFLICT.

         The execution, delivery and performance by the Purchaser of this
Agreement does not (a) conflict with or violate any provision of the charter
documents of the Purchaser or of any subscription, members' or similar agreement
or understanding to which the Purchaser is a party or by which it is bound or
(b) constitute or result in a breach of, or a default (or an event which, with
notice or lapse of time or both would constitute a default) under, or result in
the termination of, or accelerate the performance required by, or create a right
of termination or acceleration under any note, bond, mortgage or indenture,
contract, agreement, lease, sublease, license, permit, franchise or other
instrument or arrangement relating to the Purchaser's assets or properties and
to which the Purchaser is a party, (c) constitute or result in a violation by
the Purchaser of any applicable law or (d) constitute or result in a violation
by the Purchaser of any order, judgment, writ, injunction decree or award to
which it is a party or by which it is bound or affected; to the extent that each
of the foregoing would be reasonably likely to materially adversely affect the
Purchaser's ability to consummate the transactions contemplated by this
Agreement or carry out the Purchaser's obligations pursuant to this Agreement.

Section 4.3 CONSENTS AND APPROVALS.

         The execution, delivery and performance by Purchaser of this Agreement
does not and will not require any consent, approval, authorization or other
order of, action by, filing with or notification to any third party, including
without limitation, any Governmental Entity except the notification requirements
of the Competition Act (Canada).

Section 4.4 LITIGATION.

         There are no actions, suits, claims, proceedings, investigations or
governmental inquiries ongoing, pending or threatened against the Purchaser or
any of its assets or properties which seek

<PAGE>   31
                                      -27-

to delay or prevent the consummation of, or which would be reasonably likely to
materially adversely affect the Purchaser's ability to consummate the
transactions contemplated by this Agreement.

Section 4.5 FINANCING.

         As of the date hereof, Purchaser has sufficient funds, or has obtained
binding commitments from responsible financial institutions to enable it to
borrow such funds, as are needed to pay the Purchase Price in cash on the
Closing Date, and Purchaser will maintain such funds or commitments until the
Closing.

Section 4.6 BROKERS.

         Except as to RBC Dominion Securities Inc., whose fees and expenses are
payable by the Purchaser, no broker, finder or investment banker is entitled to
any brokerage, finder's or other fee or commission in connection with the
transactions contemplated by this Agreement based upon arrangements made by or
on behalf of the Purchaser.

Section 4.7 EMPLOYEE BENEFITS.

         The Employees shall be offered employee benefits which are, in the
aggregate, comparable to the employee benefits they enjoy as of February 28,
2001.

                                   ARTICLE 5.
                       COVENANTS AND ADDITIONAL AGREEMENTS

Section 5.1 CONDUCT OF BUSINESS PRIOR TO THE CLOSING.

         Unless Purchaser otherwise agrees in writing and except as otherwise
set forth herein (including, without limitation in all Schedules hereto) between
the date of this Agreement and the Closing Date, Seller shall cause the
Corporation to conduct the Business in the ordinary course and in material
compliance with all applicable laws and regulations. Seller shall not and shall
not permit the Corporation to:

         (a)      take any action with respect to any inter-company receivable
                  or inter-company payable other than in the ordinary course of
                  business;

         (b)      except in the ordinary course of Business, purchase or sell,
                  consume or otherwise dispose of the assets of the Corporation;

         (c)      settle any accounts receivable of the Corporation at less than
                  face value net of reserve for that account;

         (d)      waive or surrender any material right of the Corporation;

<PAGE>   32
                                      -28-

         (e)      subject to Section 5.1(f), incur, discharge, satisfy or pay
                  any Encumbrance, obligation or liability in connection with
                  the Business other than in the ordinary course of business;

         (f)      make any capital expenditure or commitment in connection with
                  the Business in the aggregate in excess of $350,000;

         (g)      issue any shares in the capital of the Corporation; or

         (h)      except in the ordinary course of business pay or agree to pay
                  any increase in compensation, pension, bonus, share of profits
                  or other benefit to, or for the benefit of, any employee,
                  director, or officer of the Corporation.

Section 5.2 ACCESS TO INFORMATION.

         From the date hereof until the Closing, upon reasonable notice, Seller
and the Corporation shall, and shall cause their respective officers, directors,
employees, auditors and agents and such other officers, directors and employees
of any Affiliate of the Seller as Purchaser reasonably requires, to (a) afford
the officers, employees and authorized agents and representatives of Purchaser
reasonable access, during normal business hours, to the offices, properties,
books and records of the Corporation and (b) furnish to the officers, employees
and authorized agents and representatives of Purchaser such additional financial
and operating data and other information regarding the Business as Purchaser may
from time to time reasonably request; provided, however, that such investigation
shall not unreasonably interfere with any of the businesses or operations of
Seller or its Affiliates.

Section 5.3 CONFIDENTIALITY.

         The terms of the Non-Disclosure Agreement dated as of September 14,
2000 (the "Non-Disclosure Agreement"), between Williams Communications
Solutions, LLC and TELUS Corporation are hereby incorporated herein by reference
and shall continue in full force and effect pursuant to the terms thereof. If
this Agreement is, for any reason, terminated prior to the Closing, the
Non-Disclosure Agreement shall continue in full force and effect.
Notwithstanding the foregoing, if the Purchaser is required to disclose the
terms of this Agreement to any Governmental Entity or any creditor of the
Purchaser, such disclosure shall not be a contravention of the Non-Disclosure
Agreement. Upon Closing, the Non-Disclosure Agreement shall merge and shall
cease to be effective against either party thereto or the parties to this
Agreement and shall be replaced by the terms of Section 6.4 hereof.

Section 5.4 REGULATORY AND OTHER AUTHORIZATIONS AND CONSENTS.

         (a)      Each party hereto shall use reasonable commercial efforts to
                  obtain all authorizations, consents, orders and approvals of
                  all Governmental Entities that may be or become necessary for
                  its execution and delivery of, and the performance of its
                  obligations pursuant to, this Agreement and will cooperate
                  fully with the other parties in promptly seeking to obtain all
                  such authorizations, consents, orders and approvals. Each
                  party hereto agrees to cooperate to make all commercially
                  reasonable efforts and diligently pursue obtaining Competition
                  Act

<PAGE>   33
                                      -29-

                  Approval and make all appropriate filings pursuant to the
                  Competition Act (Canada) and the Investment Canada Act with
                  respect to the transactions contemplated hereby and to supply
                  promptly any additional information and documentary material
                  that may be requested pursuant to such legislation. No party
                  hereto shall take any action that is reasonably expected to
                  have the effect of delaying, impairing or impeding the receipt
                  of any required authorization, consent, order or approval
                  unless such action is reasonably believed to be required in
                  order to comply with any applicable law or regulation.

         (b)      Each party hereto agrees to cooperate in obtaining any other
                  consents and approvals which may be required in connection
                  with the transactions contemplated by this Agreement.

         (c)      Subject to the rights of termination under the provisions of
                  Section 8.1 of this Agreement, each party hereto shall use
                  reasonable commercial efforts to perform and fulfill all
                  conditions and obligations on its part to be performed and
                  fulfilled under this Agreement, and to cause the transactions
                  contemplated by this Agreement to be fully carried out.

Section 5.5 TAX MATTERS.

         5.5.1 Tax Indemnities.

         (a)      Notwithstanding anything in this Agreement to the contrary,
                  Seller and the Seller's Parent shall jointly and severally
                  indemnify, defend and hold the Purchaser Indemnitees harmless
                  from and against, and shall reimburse them for (i) any and all
                  Losses sustained or incurred by a Purchaser Indemnitee
                  resulting or arising from any inaccuracy in or breach of any
                  of the Seller's representations and warranties set forth in
                  Section 3.11 or any breach of any covenant, obligation or
                  agreement of Seller contained in this Agreement concerning
                  Taxes, and (ii) any and all Taxes imposed on or payable by the
                  Corporation or any predecessor of the Corporation with respect
                  to any taxation period or portion thereof that ends on or
                  before the Closing Date, in excess of the amount reserved for
                  current Taxes payable on the Closing Date Financial
                  Statements, including, without limitation, any such excess
                  Taxes relating to:

                           (A)      the sale or distribution of the Excluded
                                    Assets in accordance with this Agreement;

                           (B)      the amalgamation of the Corporation and CNG
                                    Computer Networking Group, Inc. ("CNG") on
                                    January 1, 1999 to form Wiltel
                                    Communications (Canada), Inc. and any Taxes
                                    resulting from any assessments or
                                    reassessments, if any, of the CNG Tax
                                    Returns;

                           (C)      the amalgamation of Wiltel Communications
                                    (Canada), Inc. (formerly TTS Meridian
                                    Systems, Inc.) and Wiltel Holdings, Inc. on
                                    November 1, 1997 to form Wiltel
                                    Communications (Canada),

<PAGE>   34
                                      -30-

                                    Inc. and any Taxes resulting from any
                                    assessments or reassessments, if any, of the
                                    Wiltel Communications (Canada), Inc.
                                    (formerly TTS Meridian Systems, Inc.) Tax
                                    Returns; and

                           (D)      any transactions the Corporation has
                                    undertaken with related non-residents;

                  provided, however, that no indemnity shall be provided by
                  Seller under this Section 5.5.1 for any reduction in any net
                  operating loss, capital loss or tax credit carryover allocable
                  to the Corporation on or after the Closing Date.

         (b)      Payment by the Seller of any amount due under this Section
                  5.5.1 shall be made within thirty (30) days following written
                  notice by the Purchaser or the Corporation that payment of
                  such amounts to the appropriate Governmental Entity is due,
                  provided that the Seller shall not be required to make any
                  payment earlier than two (2) days before it is due to the
                  appropriate Governmental Entity. In the case of any Taxes
                  being contested in accordance with the provisions of Section
                  5.5.3, payment of such Taxes to the appropriate Governmental
                  Entity will not be considered to be due earlier than the date
                  a final determination to such effect is made by the
                  appropriate Governmental Entity or a court or as required by
                  any prevailing legislation in respect of Taxes if earlier.

         (c)      For purposes of this Agreement, in the case of any Tax (other
                  than a Tax based upon or measured by income, a Tax based upon
                  or measured by capital or a sales tax) that is imposed on a
                  periodic basis and is payable for a period that begins before
                  the Closing Date and ends after the Closing Date, the portion
                  of such Taxes payable for the period ending on the Closing
                  Date by Seller shall be the amount of such Tax for the entire
                  period multiplied by a fraction, the numerator of which is the
                  number of days in the period ending on the Closing Date and
                  the denominator of which is the number of days in the entire
                  period.

         (d)      Any amount otherwise payable by Seller under this Section
                  5.5.1 shall be reduced by the present value of any Tax benefit
                  to Purchaser or the Corporation for a period or portion
                  thereof beginning after the Closing Date (a "Post-Closing Date
                  Tax Benefit").

         5.5.2 Refunds.

         (a)      Purchaser shall promptly pay to Seller, any refund or credit
                  (including any interest paid or credited with respect thereto
                  net of any Taxes paid or payable in respect of such interest
                  or any Taxes that would have been payable in respect of such
                  interest but for the use of deductions otherwise available to
                  shelter the payment of Taxes on such interest) received by
                  Purchaser or the Corporation of Taxes (i) relating to taxation
                  periods or portions thereof ending on or before the Closing
                  Date, or (ii) attributable to an amount paid by Seller under
                  Section 5.5.1 hereof.

         (b)      Purchaser shall, if Seller so requests and at the expense of
                  Seller, cause the Corporation to file for and obtain any
                  refund to which Seller is entitled under this

<PAGE>   35
                                      -31-

                  Section 5.5.2. Purchaser shall permit Seller to exercise
                  reasonable control (at the expense of Seller) over the
                  procedure related to such refund claim, and shall cause the
                  Corporation to authorize by appropriate power of attorney such
                  persons as Seller shall designate to represent the Corporation
                  with respect to such refund claim. Purchaser shall provide
                  Seller with reasonable access to all relevant records, books
                  and files of the Corporation as necessary or appropriate to
                  review and consider the existence and extent of any such
                  claims and the procedures and other actions that may be
                  necessary or appropriate to obtain such refunds.

         (c)      Purchaser and the Corporation shall have the right and shall
                  be given the opportunity to consult with Seller with respect
                  to any claim made to obtain any refund pursuant to this
                  Section 5.5.2, and, in respect of any such claim, to
                  participate in conferences with counsel, to receive copies of
                  all relevant documentation as it becomes available, and to
                  meet with representatives of Seller at all reasonable times to
                  discuss the claim.

         (d)      Seller and the Seller's Parent shall jointly and severally
                  indemnify, defend and hold the Purchaser Indemnitees harmless
                  from and against, and shall reimburse them for the present
                  value of any liability for Taxes imposed on or payable by the
                  Corporation in respect of a taxation period ending after the
                  Closing Date resulting directly from any attempt made by the
                  Seller, or the Corporation at the request of the Seller, to
                  obtain any refund under this Section 5.5.2.

         5.5.3 Contests.

         (a)      After the Closing Date, Purchaser or the Corporation shall
                  notify Seller in writing within twenty (20) Business Days of
                  the commencement of any Tax audit or administrative or
                  judicial proceeding in respect of a taxation period or portion
                  thereof of the Corporation ending on or before the Closing
                  Date. Such notice shall contain factual information (to the
                  extent known to Purchaser or the Corporation) describing any
                  asserted liability for Taxes in reasonable detail and shall
                  include copies of any notice or other document received from
                  any Governmental Entity in respect of any such asserted
                  liability for Taxes. The failure to give any notice required
                  by this Section 5.5.3(a) in a timely manner shall not limit
                  the obligation of Seller under Section 5.5.1 except to the
                  extent that Seller is prejudiced by such failure.

         (b)      Seller may, upon written acknowledgement of the obligation to
                  provide indemnification with respect thereto, elect to direct,
                  through counsel of its own choosing and at the expense of
                  Seller, any audit, claim for refund and administrative or
                  judicial proceeding involving any asserted Tax liability with
                  respect to which indemnity may be sought under Section 5.5.1
                  (any such audit, claim for refund or proceeding relating to an
                  asserted Tax liability is referred to herein as a "Contest").
                  If Seller elects to direct a Contest, it shall within thirty
                  (30) calendar days of receipt of the notice of the
                  commencement of a Contest, notify Purchaser of its intent to
                  do so, and Purchaser shall cooperate and shall cause the
                  Corporation or its successor to cooperate, at the expense of
                  Seller

<PAGE>   36
                                      -32-

                  (which shall not include the cost of the Corporation
                  personnel), in each phase of such Contest. If Seller elects
                  not to direct the Contest, Purchaser or the Corporation may
                  pay, compromise or contest such asserted liability; provided,
                  however, that in such case, neither Purchaser nor the
                  Corporation may settle or compromise any asserted liability
                  without the consent of Seller, which consent shall not be
                  unreasonably withheld. In any event, Seller may participate,
                  at the expense of Seller, in the Contest. If Seller chooses to
                  direct the Contest, Purchaser shall promptly empower and shall
                  cause the Corporation or its successor promptly to empower (by
                  power of attorney and such other documentation as may be
                  appropriate) such representatives of Seller, as it may
                  designate to represent Purchaser or the Corporation or its
                  successor in the Contest in so far as the Contest involves an
                  asserted Tax liability for which Seller would be liable under
                  Section 5.5.1.

         (c)      If Seller chooses to direct the Contest, Purchaser or the
                  Corporation shall have the right and shall be given the
                  opportunity to consult with Seller with respect to the
                  Contest, to participate in conferences with counsel, to
                  receive copies of all relevant documentation as it becomes
                  available, and to meet with representatives of Seller at all
                  reasonable times to discuss the Contest.

         (d)      If Seller chooses to direct the Contest, Seller may not settle
                  or compromise the Contest or any asserted liability for Taxes
                  related thereto except with the prior written consent of
                  Purchaser or the Corporation provided if Purchaser or the
                  Corporation withholds its consent to a settlement or
                  compromise of any such Contest or asserted liability for Taxes
                  which Seller is willing to accept liability for and pay the
                  cost of, then Seller shall only be liable to indemnify
                  Purchaser Indemnitees with respect to such Contest or asserted
                  liability for Taxes to the extent that the amount payable on
                  the ultimate disposition thereof is no greater than the amount
                  Seller was willing to accept liability for pursuant to the
                  settlement or compromise in respect of which the consent of
                  Purchaser or the Corporation was withheld.

         (e)      If Seller elects not to direct the Contest or fails to notify
                  Purchaser of its election as herein provided or fails to
                  acknowledge its indemnification obligation with respect
                  thereto, neither the Purchaser nor the Corporation shall be
                  held responsible for any liability for Taxes or other costs
                  paid or payable by the Seller as a result of any good faith
                  action taken by the Purchaser or the Corporation, or by the
                  failure of the Purchaser or the Corporation to take any
                  action, to settle or compromise the Contest.

         5.5.4 Preparation of Tax Returns.

         Seller shall prepare and timely file Tax Returns and schedules relating
to the Corporation for any taxation period or portion thereof ending on or prior
to the Closing Date. Purchaser shall prepare and timely file or cause the
Corporation to prepare and timely file all Tax Returns for which Seller is not
responsible pursuant to this Section 5.5.4 (the "Post-Closing Tax Returns"). If
a Post-Closing Tax Return includes a change in reporting (other than a change in
reporting that

<PAGE>   37
                                      -33-

is required by applicable law) that results in a Contest and if Seller's
reporting of items in prior years was reasonable based on professional advice
and was permitted by the relevant tax legislation, then Seller shall have no
indemnification obligations under Section 5.5.1 for liabilities resulting
directly from such reporting change. Seller shall deliver to the Purchaser or
the Corporation a complete and accurate copy of each Tax Return required to be
filed by Seller under this Section 5.5.4 and any amendment to such Tax Return,
within ten days of the date such Tax Return is filed with the appropriate
Governmental Entity.

         5.5.5 Cooperation and Exchange of Information.

         Seller and Purchaser will provide each other with such cooperation and
information as any of them reasonably may request of the other in filing any Tax
Return, amended Tax Return or claim for refund or tax indemnification,
determining a liability for Taxes or a right to a refund of Taxes or
participating in or conducting any audit or other proceeding in respect of Taxes
including all matters described in Section 5.5.3. Such cooperation and
information shall include providing copies of relevant Tax Returns or portions
thereof, together with accompanying schedules and related work papers and
documents relating to rulings or other determinations by Governmental Entities.
Each party shall make its employees available at no cost to the other on a
mutually convenient basis to provide explanations of any documents or
information provided hereunder. The Corporation will retain all Tax Returns,
schedules, work papers and material records or other documents relating to Tax
matters of the Corporation for all taxation periods or portions thereof ending
on or before the Closing Date, which were delivered by the Seller pursuant to
its obligations under this Agreement, until the later of (a) the expiration of
the statute of limitations of the taxation periods to which such Tax Returns and
other documents relate, including extensions for such taxation periods, or (b)
eight years following the due date (including extensions) for such Tax Returns.
The Seller shall be entitled to retain copies of all Tax Returns of the
Corporation relating to any taxation period or portion thereof ending on or
before the Closing Date. Any information obtained or retained under this Section
5.5.5 shall be kept confidential, except as may be otherwise necessary in
connection with the filing of Tax Returns or claims for refund or in conducting
an audit or other proceeding.

         5.5.6 Survival of Obligations in respect of Taxes.

         The obligations of the parties under this Section 5.5 shall survive the
Closing and shall terminate upon the expiration of ninety days following the
period, including any extensions thereof, during which an assessment,
reassessment, or other form of recognized document assessing liability for Taxes
could be issued with respect to Taxes for which the Seller may be liable
pursuant to its obligation to indemnify Purchaser Indemnitees under Section
5.5.1 or in the event of any liability for Taxes concerning any such assessment
or reassessment, until the assessment or reassessment is finally concluded.

         5.5.7 Miscellaneous.

         (a)      All payments made under this Section 5.5 shall be treated as
                  adjustments to the Purchase Price. However, if at any time and
                  for any reason the recipient of a payment under this Section
                  5.5 (other than Section 5.5.2) becomes liable for any Taxes in
                  respect of such payment, the payor shall indemnify and hold
                  harmless

<PAGE>   38
                                      -34-

                  the recipient from any such liability for Taxes attributable
                  to such payment and for any further Taxes attributable to
                  payments made pursuant to the payor's obligation described in
                  this sentence.

         (b)      Except as expressly provided otherwise herein and except for
                  the representations contained in Section 3.11 of this
                  Agreement, this Section 5.5 shall be the sole provision
                  governing Taxes and indemnities therefor under this Agreement.

         (c)      For purposes of this Section 5.5, all references to Seller,
                  Purchaser, the Corporation and their respective Affiliates
                  include successors and assigns thereto.

Section 5.6 NOTICE OF BREACHES.

         (a)      Seller shall promptly deliver to Purchaser written notice of
                  any event or development that would (i) render any statement,
                  representation or warranty of Seller or the Corporation in
                  this Agreement (including all Schedules) inaccurate or
                  incomplete in any material respect, or (ii) constitute or
                  result in a breach by Seller or the Corporation of, or a
                  failure by Seller or the Corporation to comply with, any
                  agreement or covenant in this Agreement applicable to Seller
                  or the Corporation, as the case may be.

         (b)      Purchaser shall promptly deliver to Seller written notice of
                  any event or development that would (i) render any statement,
                  representation or warranty of the Purchaser in this Agreement
                  inaccurate or incomplete in any material respect, or (ii)
                  constitute or result in a breach by the Purchaser of, or a
                  failure by the Purchaser to comply with, any agreement or
                  covenant in this Agreement applicable to the Purchaser.

         (c)      No disclosure under this Section 5.6 shall be deemed to avoid
                  or cure any misrepresentation or breach of any party herein.

         (d)      If the information disclosed pursuant to a notice under
                  Section 5.6(a) constitutes a Material Adverse Effect, the
                  Purchaser shall be entitled to terminate this Agreement
                  without the Seller having any cause of action or recourse
                  against the Purchaser.

Section 5.7 WILLIAMS MARKS.

         The Corporation shall enter into a license (the "Trademark License")
with the Seller and such other parties as are necessary to allow the Corporation
to use and reproduce the Williams Marks on the terms and conditions of the
license attached hereto as Schedule 5.7.

Section 5.8 ENTERPRISE SOFTWARE.

         (a)      Seller shall seek to obtain the consent of any licensors of
                  Enterprise Software to the transfer thereof to Corporation as
                  of the Closing Date on commercially reasonable and customary
                  terms. Seller's Parent and Purchaser shall (i) identify any
                  Enterprise Software that Purchaser believes will not be
                  required by

<PAGE>   39
                                      -35-

                  Corporation as of the Closing Date or thereafter or that
                  Purchaser intends to replace with software from other vendors,
                  and (ii) develop a mutually acceptable transition plan to
                  ensure that, as of the Closing Date, Corporation will have the
                  rights to operate its business without limitation or
                  restriction and without violating any law or the proprietary
                  rights of any licensor of any Enterprise Software.

         (b)      To the extent that any Enterprise Software cannot be
                  transferred to Corporation on or prior to the Closing Date or
                  that the use of such Enterprise Software from and after the
                  Closing Date will violate any law or the terms of any
                  applicable license agreement, Seller's Parent shall obtain the
                  consent of the licensor to allow Corporation temporary
                  continued use of the Enterprise Software until the transfer of
                  the license rights or shall make the Enterprise Software
                  available to Corporation through the Transition Services
                  Agreement, without materially diminishing the functionality or
                  performance of same. To the extent that the Seller and
                  Purchaser determine that any Enterprise Software cannot be
                  assigned to Corporation on or prior to the Closing Date and
                  cannot be used or made available to Corporation through the
                  Transition Services Agreement without violating any law or
                  applicable license agreement, the parties shall determine
                  whether other software can be licensed or otherwise acquired
                  by Corporation in lieu of such Enterprise Software and shall
                  use commercially reasonable efforts to license or acquire such
                  alternate software for Corporation.

         (c)      The parties acknowledge and agree that it is their intent to
                  work together to ensure that Corporation (i) is not limited in
                  its operations in any way due to the failure to transfer or
                  otherwise make available to Corporation all necessary
                  Enterprise Software, (ii) is not required to violate any law
                  or license agreement as the result of using any Enterprise
                  Software as of the Closing Date or thereafter, and (iii) can
                  license or acquire, no later than 90 days after the Closing
                  Date (or such longer period as Purchaser may agree in
                  writing), in their own name and not through the Transition
                  Services Agreement, the rights to the Enterprise Software or
                  alternate software acceptable to Purchaser.

         (d)      The Seller's Parent shall reimburse the Purchaser and the
                  Corporation for any incremental costs and expenses that they
                  incur to use or acquire any Enterprise Software or alternative
                  pursuant to the terms of this Article, except the Purchaser
                  and the Corporation shall bear their own costs and expenses of
                  its efforts to evaluate Enterprise Software or any
                  alternatives.

Section 5.9 CROSS LICENSE AGREEMENT.

         Software owned by Seller's Parent, The Williams Companies, Inc., and
Enterprise or a subsidiary of The Williams Companies, Inc., or Williams
Communications Solutions, LLC, which is used in the Business by the Corporation,
shall be licensed to Corporation pursuant to cross license agreements (the
"Cross License Agreement") substantially in the form attached as Schedule 5.9.
In the event that PEH succeeds to any such ownership in the above-described
software, the Seller and the Seller's Parent shall use commercially reasonable
efforts to cause PEH to settle the terms of and to sign a cross license
agreement in respect of such software.

<PAGE>   40
                                      -36-

Section 5.10 TRANSITION SERVICES AGREEMENT.

         Support services provided by Seller's Parent, The Williams Companies,
Inc., and Enterprise or a subsidiary of The Williams Companies, Inc., or
Williams Communications Solutions, LLC, which is used in the Business by the
Corporation, shall be provided to Corporation pursuant to transition services
agreements (the "Transition Services Agreement") substantially in the form
attached as Schedule 5.10. In the event that PEH acquires the means to provide
the above-described support services, the Seller and the Seller's Parent shall
use commercially reasonable efforts to cause PEH to sign a Transition Services
Agreement.

Section 5.11 DISTRIBUTION AGREEMENT.

         Software applications owned by Seller's Parent, The Williams Companies,
Inc., and Enterprise or a subsidiary of The Williams Companies, Inc., or
Williams Communications Solutions, LLC, which is used in the Business by the
Corporation, shall be licensed to Corporation and the Corporation shall be
entitled to sublicense such software applications to its customers pursuant to a
distribution agreement (the "Distribution Agreement") substantially in the form
attached as Schedule 5.11. In the event that PEH succeeds to any such ownership
in the above-described software, the Seller and the Seller's Parent shall use
commercially reasonable efforts to cause PEH to settle the terms and sign a
distribution agreement in respect of such software.

Section 5.12 ASSETS TO BE PROVIDED BEFORE CLOSING.

         Seller's Parent, The Williams Companies, Inc. or a subsidiary of The
Williams Companies, Inc., or Williams Communications Solutions, LLC and their
successors and assigns, which include without limitation PEH, shall provide the
assets listed in Schedule 2.5(d) to the Corporation prior to the Closing Date.

                                   ARTICLE 6.
                              CONDITIONS TO CLOSING

Section 6.1 CONDITIONS TO OBLIGATIONS OF SELLER.

         The obligations of Seller to consummate the transactions contemplated
by this Agreement shall be subject to the fulfillment or waiver by the Seller,
at or prior to the Closing, of each of the following conditions:

         (a)      Representations and Warranties; Covenants. The representations
                  and warranties of the Purchaser contained in this Agreement
                  shall be true and correct in all material respects as of the
                  Closing, with the same force and effect as if made as of the
                  Closing, other than such representations and warranties as are
                  made as of another date which shall be true and correct in all
                  material respects as of such date. The covenants contained in
                  this Agreement to be complied with by the Purchaser on or
                  before the Closing shall have been complied with in all
                  material respects, and Seller shall have received a
                  certificate of the Purchaser to such effect signed by a duly
                  authorized officer thereof.

<PAGE>   41

                                      -37-

         (b)      Approvals. Any required consent, approval or waiting period
                  (and any extension thereof) applicable to the purchase of the
                  Purchased Shares contemplated hereby shall have been received,
                  expired or shall have been terminated, as appropriate. Without
                  limiting the generality of the foregoing, (i) either (a) the
                  Commissioner of Competition (the "Commissioner") shall have
                  issued an advance ruling certificate (an "ARC") under section
                  102 of the Competition Act in respect of the transaction
                  contemplated in this Agreement and shall not have subsequently
                  withdrawn or purported to have withdrawn such ARC prior to the
                  acquisition by the Purchaser of the Purchased Shares pursuant
                  to this Agreement or have stated or otherwise indicated that
                  he has obtained new information as a result of which he is no
                  longer satisfied that he would not have sufficient grounds on
                  which to apply to the Competition Tribunal under section 92 of
                  the Competition Act with respect to the transaction
                  contemplated in this Agreement; or (b) the applicable time
                  period under section 123 of the Competition Act shall have
                  expired, and the Commissioner or his authorized representative
                  shall have advised the Seller (on terms and in a form
                  satisfactory to the Seller) that the Commissioner does not
                  intend to make an application under section 92 of the
                  Competition Act in respect of the transaction contemplated in
                  this Agreement and neither the Commissioner nor any of his
                  representatives shall have rescinded or amended such advice;
                  and (ii) any applicable waiting period under the
                  Hart-Scott-Rodino Antitrust Improvements Act of 1976, and any
                  other applicable foreign competition laws, shall have expired.

         (c)      No Order. No Governmental Entity shall have enacted, issued,
                  promulgated, enforced or entered any statute, rule,
                  regulation, injunction or other order which is in effect and
                  has the effect of making the transactions contemplated by this
                  Agreement illegal or otherwise restraining or prohibiting
                  consummation of such transactions; provided, however, that the
                  parties hereto shall use their reasonable efforts to have any
                  such order or injunction vacated.

         (d)      The Excluded Assets. All actions shall have been taken to
                  distribute to Seller (or otherwise dispose of) all of the
                  assets and liabilities included in and as contemplated by
                  Section 2.5.

         (e)      Execution of the Ancillary Agreements. The Corporation and PEH
                  shall have entered into the Transition Services Agreement, the
                  Distribution Agreement and the cross license agreement between
                  the Corporation and PEH referred to in Section 5.9; and the
                  Corporation and TWC or its Affiliates shall have entered into
                  the Transition Services Agreement, the Trademark License and
                  the Cross License Agreement, all of which are referred to
                  collectively as the "Ancillary Agreements".

<PAGE>   42
                                      -38-

Section 6.2 CONDITIONS TO OBLIGATIONS OF THE PURCHASER.

         The obligations of the Purchaser to consummate the transactions
contemplated by this Agreement shall be subject to the fulfillment or waiver by
the Purchaser, at or prior to the Closing, of each of the following conditions
precedent:

         (a)      The representations and warranties of the Seller, the Seller's
                  Parent and the Corporation contained in this Agreement, or in
                  any certificate or other document delivered to the Purchaser
                  pursuant hereto, shall be true and correct in all material
                  respects on or as of the Closing Date, with the same force and
                  effect as if made as of the Closing, other than such
                  representations and warranties as are made as of another date
                  which shall be true and correct in all material respects as of
                  such date. The covenants contained in this Agreement to be
                  complied with by Seller, the Seller's Parent or the
                  Corporation on or before the Closing shall have been complied
                  with in all material respects, and Purchaser shall have
                  received certificates from Seller to such effect signed by a
                  duly authorized officer thereof.

         (b)      Since December 31, 2000, except for the sale of the CNG
                  Business pursuant to the CNG Business Sale Agreement, no
                  change shall have occurred in the business, operations,
                  results of operations, assets, liabilities, capitalization or
                  condition (financial or otherwise), of the Corporation,
                  whether or not in the ordinary course of business, whether
                  separately or in aggregate with other occurrences or
                  developments, and whether insured against or not, which could
                  be reasonably expected to have a Material Adverse Effect on
                  the Corporation.

         (c)      At or before the Closing Date, there will have been obtained
                  from all appropriate federal, provincial, state, municipal and
                  other governmental or administrative bodies or any other
                  person all such approvals and consents in form and on terms
                  satisfactory to counsel for the Purchaser as may be required
                  in order to permit the change in ownership of the Purchased
                  Shares as herein contemplated without affecting or resulting
                  in any cancellation or termination of or reduction of any
                  right under any material permit, license, contract, agreement
                  or lease held by the Corporation.

         (d)      Without limiting the generality of Sub-section 6.2(c): (i)
                  either (a) the Commissioner of Competition (the
                  "Commissioner") shall have issued an advance ruling
                  certificate (an "ARC") under section 102 of the Competition
                  Act in respect of the transaction contemplated in this
                  Agreement and shall not have subsequently withdrawn or
                  purported to have withdrawn such ARC prior to the acquisition
                  by the Purchaser of the Purchased Shares pursuant to this
                  Agreement or have stated or otherwise indicated that he has
                  obtained new information as a result of which he is no longer
                  satisfied that he would not have sufficient grounds on which
                  to apply to the Competition Tribunal under section 92 of the
                  Competition Act with respect to the transaction contemplated
                  in this Agreement; or (b) the applicable time period under
                  section 123 of the Competition Act shall have expired, and the
                  Commissioner or his authorized representative shall have
                  advised the Purchaser (on terms and in a form satisfactory to
                  the Purchaser) that

<PAGE>   43
                                      -39-

                  the Commissioner does not intend to make an application under
                  section 92 of the Competition Act in respect of the
                  transaction contemplated in this Agreement and neither the
                  Commissioner nor any of his representatives shall have
                  rescinded or amended such advice; and (ii) any applicable
                  waiting period under the Hart-Scott-Rodino Antitrust
                  Improvements Act of 1976, and any other applicable foreign
                  competition laws, shall have expired.

         (e)      No action or proceeding by law or in equity will be pending or
                  threatened by any person to enjoin or prohibit: (i) the
                  purchase and sale of the Purchased Shares contemplated hereby
                  or the right of the Purchaser to own the Purchased Shares, or
                  (ii) the right of each the Corporation to carry on the
                  Business.

         (f)      All actions shall have been taken to distribute to Seller (or
                  otherwise dispose of) all of the assets and liabilities,
                  included in and as contemplated by Section 2.5 and a
                  certificate from an officer of each of the Seller and the
                  Seller's Parent that the CNG Business has been sold pursuant
                  to the CNG Business Sale Agreement and all filings and
                  remittances have been made by the Corporation.

         (g)      No legislation (whether by statute, by-law, regulation or
                  otherwise) shall have been enacted, introduced or announced
                  which, in the reasonable opinion of the Purchaser, adversely
                  affects or may adversely affect the operations of the
                  Business.

         (h)      Any obligations or agreements of the Corporation which will or
                  may in any way materially inhibit the current or future
                  operations and businesses of the Purchaser and its
                  subsidiaries (including without limitation the Corporation, if
                  acquired), including without limitation, the supply agreement
                  between ATT Canada and the Corporation, effective upon Closing
                  Date, being cancelled or amended upon terms and conditions
                  satisfactory to the Purchaser.

         (i)      Execution and delivery of the Ancillary Agreements.

         (j)      The Seller and the Purchaser shall work co-operatively and in
                  good faith to cause PEH to enter into agreement(s) (the
                  "Canadian Customers Agreement") with the Purchaser, on terms
                  and conditions mutually satisfactory to the Purchaser and PEH
                  or otherwise effect the assignment of the Canadian portion of
                  the those agreements listed in Schedule 6.2(j) such that after
                  Closing, the Corporation will continue to serve such customers
                  in Canada, and receive revenues in Canada which relate to any
                  goods and services relating to the Business purchased by such
                  customers in Canada.

Section 6.3 REASONABLE EFFORTS.

         Seller shall cause the conditions in Section 6.2 to be satisfied
provided that where such conditions are dependant upon third party performance,
the Seller shall use its reasonable efforts to obtain satisfaction of such
conditions. Purchaser shall cause the conditions referred to in Section 6.1 to
be satisfied provided that where such conditions are dependant upon third party
performance, the Purchaser shall use its reasonable efforts to obtain
satisfaction of such

<PAGE>   44
                                      -40-

conditions. Except as expressly provided in this Agreement, each of the parties
agrees to use its reasonable efforts to assist and co-operate with the other
part hereto in doing, all things necessary, proper or advisable to consummate
and make effective, in the most expeditious manner practicable, the transactions
contemplated by this Agreement, including (i) the fulfilling of the conditions
of Closing, including the execution and delivery of all agreements or other
documents contemplated hereunder to be so executed and delivered, (ii) the
obtaining of all necessary waivers, consents and approvals from governmental or
regulatory agencies or authorities and the making of all necessary registrations
and filings (including filings with governmental or regulatory agencies or
authorities, if any) and the taking of all reasonable steps as may be necessary
to obtain any approval or waiver from, or to avoid any action or proceeding by,
any governmental agency or authority, (iii) the obtaining of all necessary
consents, approvals or waivers from third parties, and (iv) the defending of any
suits, actions or any other legal proceedings challenging this Agreement or the
consummation of the transactions contemplated hereby.

Section 6.4 NON-COMPETITION, CONFIDENTIALITY AND NON-SOLICITATION

         (a) Confidentiality

                  (i)      Seller and Seller's Parent

                  Up to and following completion of the transactions
                  contemplated by the Sale and Purchase Agreement, each of the
                  Seller and the Seller's Parent shall hold in strict confidence
                  and shall not use, or disclose to any Third Party, any
                  confidential or proprietary information or material of any
                  kind relating to the Business, including financial data,
                  business plans, customer names and lists, products, services,
                  Intellectual Property, trade practices and know-how pertaining
                  to any of the Corporation, the Purchase Price and the terms of
                  this Agreement. The Seller and the Seller's Parent agree that
                  all restrictions contained in this Section 6.4(a) are
                  reasonable and valid and all defences to the strict
                  enforcement thereof by the Corporation and the Purchaser are
                  hereby waived by them.

                  Obligations of the Seller and the Seller's Parent arising
                  under this Section 6.4(a) do not apply to any information
                  that:

                           (A)      is or becomes publicly available through no
                                    act or omission of the Seller and the
                                    Seller's Parent intending to use or disclose
                                    such information;

                           (B)      is furnished in good faith to the Seller and
                                    the Seller's Parent by a Third Party
                                    lawfully in possession of the information
                                    and not in breach of any confidentiality
                                    obligation;

                           (C)      is reasonably required to be disclosed:

                                    (A)      to, or pursuant to the order of, a
                                             court, tribunal or a governmental
                                             authority (including Canada Customs
                                             Revenue Agency or a regulated stock
                                             exchange) where the

<PAGE>   45
                                      -41-

                                             Seller and the Seller's Parent are
                                             required to make such disclosure
                                             pursuant to any applicable laws; or

                                    (B)      by Seller and the Seller's Parent
                                             in pursuing or defending Claims;

                                    provided that prior to any such disclosure
                                    in (i) or (ii) above, the Seller and the
                                    Seller's Parent shall notify the Corporation
                                    and the Purchaser promptly of such
                                    requirement so that the Corporation and the
                                    Purchaser may seek a protective order or
                                    other appropriate remedy. If no such
                                    protective order or other remedy is
                                    obtained, the Seller and the Seller's Parent
                                    will furnish or disclose only that
                                    information that they are advised by their
                                    legal counsel is required to be released by
                                    such Applicable Laws, or in order to
                                    properly pursue or defend any Claims, and
                                    only to the Persons and to the extent
                                    reasonably required, and the Seller and the
                                    Seller's Parent will exercise their
                                    commercial best efforts to obtain assurances
                                    from such court, tribunal, or governmental
                                    authority that confidential treatment will
                                    be given to such information so disclosed;
                                    or

                           (D)      is disclosed to the Seller's and the
                                    Seller's Parent's professional legal or
                                    financial advisor provided such legal or
                                    financial advisor is required to hold such
                                    information in confidence on terms and
                                    conditions substantially similar to the
                                    terms and conditions imposed on the Seller
                                    and the Seller's Parent by this Section.

                  (ii)     Purchaser

                  Up to and following completion of the transactions
                  contemplated by the Sale and Purchase Agreement, the Purchaser
                  shall hold in strict confidence and shall not use, or disclose
                  to any Third Party, any confidential or proprietary
                  information or material of any kind relating to the Seller and
                  the Seller's Parent, including financial data, business plans,
                  customer names and lists, products, services, Intellectual
                  Property, trade practices and know-how pertaining to any of
                  the Seller or the Seller's Parent, the Purchase Price and the
                  terms of this Agreement. The Purchaser agrees that all
                  restrictions contained in this Section 6.4(a) are reasonable
                  and valid and all defences to the strict enforcement thereof
                  by the Seller and the Seller's Parent are hereby waived by the
                  Purchaser.

                  Obligations of the Purchaser arising under this Section 6.4(a)
                  do not apply to any information that:

                           (A)      is or becomes publicly available through no
                                    act or omission of the Purchaser intending
                                    to use or disclose such information;

<PAGE>   46
                                      -42-

                           (B)      is furnished in good faith to the Purchaser
                                    by a Third Party lawfully in possession of
                                    the information and not in breach of any
                                    confidentiality obligation;

                           (C)      is reasonably required to be disclosed:

                                    (A)      to, or pursuant to the order of, a
                                             court, tribunal or a governmental
                                             authority (including Canada Customs
                                             Revenue Agency or a regulated stock
                                             exchange) where the Purchaser is
                                             required to make such disclosure
                                             pursuant to any applicable laws; or

                                    (B)      by Purchaser in pursuing or
                                             defending Claims;

                                    provided that prior to any such disclosure
                                    in (A) or (B) above, the Purchaser shall
                                    notify the Seller and the Seller's Parent
                                    and the Purchaser promptly of such
                                    requirement so that the Seller and the
                                    Seller's Parent may seek a protective order
                                    or other appropriate remedy. If no such
                                    protective order or other remedy is
                                    obtained, the Purchaser will furnish or
                                    disclose only that information that they are
                                    advised by their legal counsel is required
                                    to be released by such Applicable Laws, or
                                    in order to properly pursue or defend any
                                    Claims, and only to the Persons and to the
                                    extent reasonably required, and the
                                    Purchaser will exercise their commercial
                                    best efforts to obtain assurances from such
                                    court, tribunal, or governmental authority
                                    that confidential treatment will be given to
                                    such information so disclosed; or

                           (D)      is disclosed to the Seller's and the
                                    Seller's Parent's professional legal or
                                    financial advisor provided such legal or
                                    financial advisor is required to hold such
                                    information in confidence on terms and
                                    conditions substantially similar to the
                                    terms and conditions imposed on the
                                    Purchaser by this Section.

         (b)      Non-Competition and Non-Solicitation

                  (i)      Except as specifically provided for herein, none of
                           the Seller and the Seller's Parent shall, directly or
                           indirectly (through one or more of the Seller or the
                           Seller's Affiliates), for a period following the
                           Closing Date until December 31, 2002:

                           (A)      Compete with the Corporation in the business
                                    of sales, procurement, installation, support
                                    and/or maintenance activities in relation to
                                    telecommunication equipment located on
                                    enterprise customers' premises, excluding
                                    any such sales, installation, support and/or
                                    maintenance activities as are carried out in
                                    support of the network and broadband media
                                    businesses carried out by Seller's Parent.
                                    (the "Restricted Business") within Canada;
                                    or

<PAGE>   47
                                      -43-

                           (B)      enter into, invest, sponsor, promote, foster
                                    or otherwise participate in the ownership,
                                    conduct, operation or management of any
                                    person (including in the capacity of an
                                    employee of or consultant to such person)
                                    engaged primarily in a business similar to,
                                    or the same as, the Restricted Business in
                                    Canada in competition with Corporation,
                                    provided that nothing herein shall prohibit
                                    the acquisition by the Seller and the
                                    Seller's Parent collectively of not more
                                    than five percent (5%) of the total voting
                                    power of any publicly traded person.

                  (ii)     All parties to this Agreement, including the Seller
                           and the Seller's Parent, agree that if any part of
                           Section is held unenforceable at law or in equity,
                           then the foregoing covenant shall be reduced in scope
                           or limited as to term, geographical area or otherwise
                           to the extent deemed necessary, as determined by the
                           Corporation, acting in its absolute discretion, so
                           that the foregoing, as so reduced or limited, is
                           enforceable at law and in equity and the
                           unenforceable part shall be deemed to be severed from
                           the balance, which balance shall survive and be of
                           full of force and effect as among the parties to this
                           Agreement.

                  (iii)    None of the Seller and the Seller's Parent shall,
                           directly or indirectly, for a period of one year
                           following the Closing Date, (a) solicit, directly or
                           indirectly, trade in the Restricted Business in
                           Canada, or (b) intentionally interfere with the
                           customer relationships of Corporation.

                  (iv)     None of the Seller and the Seller's Parent shall,
                           directly or indirectly, for a period of one year
                           following the Closing Date, solicit or induce, or
                           attempt to solicit or induce, any Employee to leave
                           employment with the Corporation for any reason
                           whatsoever. For the purposes of this section, the
                           publication or advertisement by Seller and the
                           Seller's Parent of a general solicitation for
                           employment in a newspaper, trade journal or other
                           publication or media of general interest, and the
                           employment of any Employee who responds to a general
                           solicitation for employment not targeted at a
                           specific employee, shall not be a breach hereof. In
                           addition to the foregoing, neither the Seller nor the
                           Seller's Parent shall hire the employees listed in
                           Schedule 6.4(b)(iv) for a period of one year
                           following the Closing Date.

                  (v)      The Purchaser shall not, directly or indirectly, for
                           a period of one year following the Closing Date,
                           solicit or induce, or attempt to solicit or induce,
                           any employee of Seller or any of its Affiliates that
                           the Purchaser has been introduced to in connection
                           with the transaction contemplated in this Agreement,
                           save and except the Employees, to leave such employ
                           for any reason whatsoever. For the purposes of this
                           section, the publication or advertisement by the
                           Purchaser of a general solicitation for employment in
                           a newspaper, trade journal or other publication or
                           media of general interest, and the employment of any
                           employee of Seller or any of its

<PAGE>   48
                                      -44-

                           Affiliates who responds to a general solicitation for
                           employment not targeted at a specific employee, shall
                           not be a breach hereof.

                                   ARTICLE 7.
                                 INDEMNIFICATION

Section 7.1 SURVIVAL.

         Subject to Section 7.2 and except as otherwise provided in Section
5.5.6, the representations, warranties, covenants and agreements contained in
this Agreement or any schedule, certificate, document or statement delivered
hereto or thereto shall survive the Closing. Notwithstanding the foregoing, the
representations and warranties contained in or made pursuant to this Agreement
or any schedule, certificate, document or statement delivered hereto or thereto
and the related indemnity obligations set forth in Section 7.2 shall terminate
on, and no claim or action with respect thereto may be brought after, the second
anniversary of the Closing Date, except that (i) the representations and
warranties with respect to Seller's title to the Purchased Shares set forth in
Section 3.3 and any claims arising from the sale of the CNG Business shall
survive until the expiration of the applicable statute of limitations, including
any extension thereof and except that (ii) the representations and warranties
set out in Section 3.18 as they apply to ownership and rights in intellectual
property embodied in those items set out in Schedule 7.1 shall survive for a
period of five (5) years following the Closing Date, which shall be reduced to
two (2) years to the extent that proof of the Corporation's ownership or rights
to use (and modify as the case may be) such software is provided to the
Purchaser. The expiration of any representation and warranty shall not affect
any Claim made prior to the date of such expiration, but shall extinguish a
party's rights under Claims not made prior to such date.

Section 7.2 INDEMNIFICATION.

         (a)      From and after the Closing Date, Seller and Seller's Parent
                  shall jointly and severally indemnify, defend, and hold the
                  Purchaser Indemnitees harmless from and against, and shall
                  reimburse them for, any and all demands, claims, losses,
                  liabilities, damages, costs, and expenses whatsoever
                  (including without limitation, any fines, penalties,
                  reasonable fees and disbursements of counsel incurred in
                  investigating or defending any of the foregoing, and other
                  reasonable expenses incurred investigating or defending any of
                  the foregoing or enforcing this Agreement) (individually a
                  "Loss" and collectively "Losses") sustained or incurred by a
                  Purchaser Indemnitee resulting or arising from (i) any
                  inaccuracy in or breach of any of Seller's representations and
                  warranties set forth in this Agreement or in any agreement
                  contemplated hereby or executed in connection herewith, or in
                  any Schedule or Exhibit hereto or thereto, or in any
                  certificate or other instrument delivered or to be delivered
                  by or on behalf of a Seller pursuant hereto or thereto, (ii)
                  any breach of any covenant, obligation or agreement of Seller
                  contained in this Agreement or in any agreement contemplated
                  hereby or executed in connection herewith, or in any Schedule
                  or Exhibit hereto or thereto, or in any certificate or other
                  instrument delivered or to be delivered by or on behalf of
                  Seller pursuant hereto or thereto, or (iii) any liabilities
                  and obligations

<PAGE>   49
                                      -45-

                  related to the CNG Business and the Excluded Assets including,
                  without limitation, the assumption and satisfaction of
                  obligations by Milgo Solutions Canada Company under the terms
                  of the CNG Business Sale Agreement.

         (b)      From and after the Closing Date, the Purchaser and the
                  Corporation shall jointly and severally indemnify, defend, and
                  hold the Seller Indemnitees harmless from and against, and
                  shall reimburse them for, any and all Losses sustained or
                  incurred by a Seller Indemnitee resulting or arising from (i)
                  any inaccuracy in or breach of any of Purchaser's
                  representations or warranties set forth in this Agreement or
                  in any agreement contemplated hereby or executed in connection
                  herewith, or in any Schedule or Exhibit hereto or thereto, or
                  in any certificate or other instrument delivered or to be
                  delivered by or on behalf of Purchaser pursuant hereto or
                  thereto, or (ii) any breach of any covenant, obligation or
                  agreement of Purchaser contained in this or in any agreement
                  contemplated hereby or executed in connection herewith, or in
                  any Schedule or Exhibit hereto or thereto, or in any
                  certificate or other instrument delivered or to be delivered
                  by or on behalf of Purchaser pursuant hereto or thereto.

         (c)      Losses shall be computed net of payments received by the
                  Indemnified Party under any insurance policy or collected from
                  third parties with respect to such Losses. All Losses paid
                  pursuant to this Article 7 will be treated as adjustments to
                  the Purchase Price. However, if at any time and for any reason
                  the recipient of a payment on account of Losses becomes liable
                  for any Taxes in respect of such payment, the payor shall
                  indemnify and hold harmless the recipient from any such
                  liability for Taxes attributable to such payment and for any
                  further Taxes attributable to payments made pursuant to the
                  payor's obligation described in this sentence.

         (d)      The party making a claim (except for a claim for Taxes) under
                  this Section 7 is referred to as the "Indemnified Party" and
                  the party against whom such claims are asserted under this
                  Section 7 is referred to as the "Indemnifying Party". All
                  claims by any Indemnified Party under this Section 7 shall be
                  asserted and resolved as follows:

                  (i)      in the event that any claim or demand for which an
                           Indemnifying Party would be liable to an Indemnified
                           Party hereunder is asserted against or sought to be
                           collected from such Indemnified Party by a third
                           party, the Indemnified Party shall with reasonable
                           promptness notify in writing the Indemnifying Party
                           of such claim or demand, specifying the nature of the
                           specific basis for such claim or demand, and the
                           amount or the estimated amount thereof to the extent
                           then feasible (which estimate shall not be conclusive
                           of the final amount of such claim and demand; the
                           "Claim Notice"); provided, however, that any failure
                           to give such Claim Notice will not be deemed a waiver
                           of any rights of the Indemnified Party except to the
                           extent the rights of the Indemnifying Party are
                           actually prejudiced by such failure. At the request
                           of any Indemnifying Party, the Indemnified Party
                           shall cooperate with the Indemnifying Party to make
                           claims under

<PAGE>   50
                                      -46-

                           any insurance policies which may partially or wholly
                           reimburse the Indemnified or Indemnifying Party for
                           any Losses resulting from the claims or demands
                           specified in the Claim Notice and to make claims
                           against any third parties which may be wholly or
                           partially responsible for such Losses, and use
                           reasonable efforts to collect under such insurance
                           policies or from such third parties. The Indemnifying
                           Party, upon request of the Indemnified Party, shall
                           retain counsel (who shall be reasonably acceptable to
                           the Indemnified Party) to represent the Indemnified
                           Party and shall pay the fees and disbursements of
                           such counsel with regard thereto; provided, however,
                           that any Indemnified Party is hereby authorized prior
                           to the date on which it receives written notice from
                           the Indemnifying Party designating such counsel, to
                           retain counsel, whose fees and expenses shall be at
                           the expense of the Indemnifying Party, to file any
                           motion, answer or other pleading and take such other
                           action which it reasonably shall deem necessary to
                           protect its interests or those of the Indemnifying
                           Party until the date on which the Indemnified Party
                           receives such notice from the Indemnifying Party.
                           After the Indemnifying Party shall retain such
                           counsel, the Indemnified Party shall have the right
                           to retain its own counsel, but the fees and expenses
                           of such counsel shall be at the expense of such
                           Indemnified Party unless (x) the Indemnifying Party
                           and the Indemnified Party shall have mutually agreed
                           to the retention of such counsel, or (y) the named
                           parties of any such proceeding (including any
                           impleaded parties) include both the Indemnifying
                           Party and the Indemnified Party and representation of
                           both parties by the same counsel would be
                           inappropriate due to actual or potential differing
                           interests between them. The Indemnifying Party shall
                           not, in connection with any proceedings or related
                           proceedings in the same jurisdiction, be liable for
                           the fees and expenses of more than one such firm for
                           the Indemnified Party (except to the extent the
                           Indemnified Party retained counsel to protect its (or
                           the Indemnifying Party's) rights prior to the
                           selection of counsel by the Indemnifying Party). If
                           requested by the Indemnifying Party, the Indemnified
                           Party agrees to cooperate with the Indemnifying Party
                           and its counsel in contesting any claim or demand
                           which the Indemnifying Party defends. A claim or
                           demand may not be settled by the Indemnifying Party
                           without the prior written consent of the Indemnified
                           Party unless, as part of such settlement, the
                           Indemnified Party shall receive a full and
                           unconditional release reasonably satisfactory to the
                           Indemnified Party;

                  (ii)     so long as any right to indemnification exists
                           pursuant to this Article 7, the affected parties each
                           agree to retain all books and records related to the
                           Claim Notice. In each instance, the Indemnified Party
                           shall have the right (subject to the attorney/client
                           privilege) to be kept fully informed by the
                           Indemnifying Party and its legal counsel with respect
                           to any legal proceedings. Any information or
                           documents made available to any party hereunder and
                           designated as confidential by the party providing
                           such information or documents and which is not
                           otherwise generally available

<PAGE>   51

                                      -47-

                           to the public and not already within the knowledge of
                           the party to whom the information is provided (unless
                           otherwise covered by the confidentiality provisions
                           of any other agreement among the parties hereto, or
                           any of them), and except as may be required by
                           applicable law, shall not be disclosed to any third
                           Person (except for the representatives of the party
                           being provided with the information, in which event
                           the party being provided with the information shall
                           request its representatives not to disclose any such
                           information which is otherwise required hereunder to
                           be kept confidential).

         (e)      Anything contained in this Agreement to the contrary
                  notwithstanding, (i) Seller shall not be liable for any
                  amounts for which Purchaser is entitled to indemnification
                  unless and until the aggregate amount for which Purchaser is
                  entitled to indemnification from Seller pursuant to this
                  Agreement exceeds the threshold amount of One Million Dollars
                  ($1,000,000) (the "Threshold"), at which time Seller shall be
                  liable for all amounts for which the Purchaser Indemnitees are
                  entitled to indemnification; and (ii) neither the Seller or
                  the Seller's Parent on the one hand, nor the Purchaser or the
                  Corporation on the other hand, shall be required to make
                  indemnification payments pursuant to this Section 7.2 that
                  exceed in the aggregate Nineteen Million Dollars
                  ($19,000,000). In determining whether the foregoing Threshold
                  amount has been exceeded and in otherwise determining the
                  amount to which the Indemnified Party is entitled to assert a
                  claim for indemnification pursuant to this Section 7.2, only
                  actual, and not consequential or other special losses, shall
                  be indemnifiable.

Section 7.3 TAX MATTERS.

         The rights and obligations of the parties with respect to
indemnification for any and all Taxes shall be governed by Section 5.5 except
that any amounts for which Purchaser is entitled to indemnification under
Section 5.5 shall form part of the aggregate amount for which Purchaser is
entitled to indemnification from Seller pursuant to this Agreement for the
purposes of Section 7.2(e) and will therefore be subject to the Threshold
provisions therein.

                                   ARTICLE 8.
                             TERMINATION AND WAIVER

Section 8.1 TERMINATION.

         This Agreement may be terminated at any time prior to the Closing:

         (a)      by the mutual written consent of Seller and Purchaser;

         (b)      by Purchaser, if any of the conditions set forth in Section
                  6.2 are not satisfied on or prior to, or, in the reasonable,
                  good faith determination of Purchaser, not capable of being
                  satisfied on or prior to the Closing Date, and shall not have
                  been waived by Purchaser;

<PAGE>   52
                                      -48-

         (c)      by Seller, if any of the conditions set forth in Section 6.1
                  are not satisfied on or prior to, or, in the reasonable, good
                  faith determination of Seller, not capable of being satisfied
                  on or prior to the Closing Date, and shall not have been
                  waived by Seller;

         (d)      by the Purchaser if the sale of the CNG Business is not
                  completed, as provided in Section 2.5 of this Agreement;

         (e)      by any party if the Closing has not taken place by July
                  31,2001;

provided, however, that the party seeking termination pursuant to clause (b),
(c), (d) or (e) is not in material breach of any of its representations,
warranties, covenants or agreements contained in this Agreement.

Section 8.2 EFFECT OF TERMINATION.

         In the event of termination of this Agreement as provided in Section
8.1, this Agreement shall forthwith become void and there shall be no liability
on the part of any party hereto except as set forth in, Section 5.3, Section
7.2, Section 9.1 and Section 9.3, and nothing herein shall relieve either party
from liability for any willful breach hereof.

Section 8.3 WAIVER.

         At any time prior to the Closing, any party may (a) extend the time for
the performance of any of the obligations or other acts of any other party
hereto, (b) waive any inaccuracies in the representations and warranties
contained herein or in any document delivered pursuant hereto, or (c) waive
compliance with any of the agreements or conditions contained herein. Any such
extension or waiver shall be valid only if set forth in an instrument in writing
signed by the party to be bound thereby or its solicitors on behalf of the party
to be bound. Any waiver of any term or condition shall not be construed as a
waiver of any subsequent breach or a subsequent waiver of the same term or
condition, or a waiver of any other term or condition, of this Agreement. The
failure of any party to assert any of its rights hereunder shall not constitute
a waiver of any of such rights.

                                   ARTICLE 9.
                                  MISCELLANEOUS

Section 9.1 EXPENSES.

         Except as otherwise may be agreed in writing or as otherwise expressly
provided 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, with the understanding that the legal fees and expenses and other
costs and expenses incurred by the Corporation are expenses of, and shall be
paid by, the Seller and not by the Corporation.

<PAGE>   53
                                      -49-

Section 9.2 NOTICES.

         All notices and other communications given or made pursuant hereto
shall be in writing and shall be deemed to have been given or made when
delivered personally or three Business Days after having been sent by registered
or certified mail, postage prepaid, return receipt requested, or one Business
Day after having been sent by facsimile transmission or by Federal Express or
other comparable nationally recognized overnight courier service (receipt
requested), to the respective parties at the following addresses (or at such
other address for a party as shall be specified in a notice given in accordance
with this Section):

If to Seller or Seller's Parent to:
                  Williams Communications, LLC
                  One Williams Center
                  Tulsa, Oklahoma 74172
                  Attn:  James W. Dutton
                  Fax:  (918) 573-6216

With copies to:
                  P. David Newsome, Jr., General Counsel
                  Williams Communications Group, Inc.
                  One Williams Center, Suite 4100
                  Tulsa, Oklahoma 74172
                  Fax:  (918) 573-3005

                  John N. Hove
                  Conner & Winters,
                  A Professional Corporation
                  3700 First Place Tower
                  15 East Fifth Street
                  Tulsa, Oklahoma 74103
                  Fax:  (918) 586-8547

If to Purchaser to:
                  21 - 3777 Kingsway
                  Burnaby, B.C., Canada V5H 3Z7
                  Attn:    James W. Peters, Executive Vice President,
                   Corporate Development and General Counsel
                  Fax:  (604) 437-8560

Section 9.3 PUBLIC ANNOUNCEMENTS.

         Except as required by law, rules or regulations of any stock exchange
or Governmental Entity, from the date hereof through the Closing Date, no party
to this Agreement shall make, or cause to be made, any press release or public
announcement in respect of this Agreement or the transactions contemplated
hereby or otherwise communicate with any news media without the prior written
consent of the other party, and the parties shall cooperate as to the timing and
contents of any such press release or public announcement.

<PAGE>   54
                                      -50-

Section 9.4 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 9.5 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 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 9.6 ENTIRE AGREEMENT.

         This Agreement (including the Schedules and the other documents and
instruments referred to herein) constitute the entire agreement of the parties
hereto with respect to the subject matter hereof and thereof and supersede all
prior agreements and undertakings, both written and oral, between the parties
hereto with respect to the subject matter hereof and thereof.

Section 9.7 ASSIGNMENT.

         Neither this Agreement nor any of the parties' rights, interests or
obligations hereunder shall be assignable by operation of law or otherwise by
either party hereto without the prior written consent of the other parties
hereto, which consent may not be unreasonably withheld. Notwithstanding the
foregoing, Purchaser shall be entitled to assign this Agreement and it's rights,
interests and obligations under this Agreement to an Affiliate, provided however
that such assignment shall not relieve the Purchaser from its obligation to
complete the transaction and perform the Purchaser's obligations contemplated in
this Agreement on the terms described herein. Any attempted assignment of this
Agreement in breach of this provision shall be void and of no effect.

Section 9.8 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 Person other than the parties
hereto or their respective successors or assigns, any legal or equitable right,
benefit or remedy or any nature whatsoever under or by reason of this Agreement,
including without limitation any rights of employment.

Section 9.9 AMENDMENT.

         This Agreement may not be amended or modified except by an instrument
in writing signed by, or on behalf of, Seller and Purchaser.

<PAGE>   55
                                      -51-

Section 9.10 GOVERNING LAW.

         This Agreement shall be governed by, and construed in accordance with,
the laws of the Province of Ontario and the Federal laws of Canada applicable
therein.

Section 9.11 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 9.12 FACSIMILE SIGNATURES.

         This Agreement and any other document or agreement executed in
connection herewith (other than any document for which an originally executed
signature page is required by law) may be executed by delivery of a facsimile
copy of an executed signature page with the same force and effect as the
delivery of an originally executed signature page. In the event any party
delivers a facsimile copy of a signature page to this Agreement or any other
document or agreement executed in connection herewith, such party shall deliver
an originally executed signature page within three Business Days of delivering
such facsimile signature page or at any time thereafter upon request; provided,
however, that the failure to deliver any such originally executed signature page
shall not affect the validity of the signature page delivered by facsimile,
which has and shall continue to have the same force and effect as the originally
executed signature page.

Section 9.13 NO PRESUMPTION.

         With regard to each and every term and condition of this Agreement and
any and all agreements and instruments subject to the terms hereof, the parties
hereto understand and agree that the same have or has been mutually negotiated,
prepared and drafted and if at any time the parties hereto desire or are
requested to interpret or construe any such term or condition or any agreement
on instrument subject hereto, no consideration shall be given to the issue of
which party hereto actually prepared, drafted or requested any term or condition
of this Agreement or any agreement or instrument subject hereto.

Section 9.14 RULES OF INTERPRETATION

         In this Agreement and the Schedules:

         TIME - time is of the essence in the performance of the Parties'
         respective obligations;

         CURRENCY - unless otherwise specified, all references to money amounts
         are to lawful currency of the United States of America;

         HEADINGS - descriptive headings of Articles and Sections are inserted
         solely for convenience of reference and are not intended as complete or
         accurate descriptions of the content of such Articles or Sections;

<PAGE>   56
                                      -52-

         SINGULAR, ETC. - use of words in the singular or plural, or with a
         particular gender, shall not limit the scope or exclude the application
         of any provision of this Agreement to such person or persons or
         circumstances as the context otherwise permits;

         CONSENT - whenever a provision of this Agreement requires an approval
         or consent by a Party to this Agreement and notification of such
         approval or consent is not delivered within the applicable time
         limited, or within any extension of the time agreed to by the Parties,
         then, unless otherwise specified, the Party whose consent or approval
         is required shall be conclusively deemed to have withheld its approval
         or consent;

         CALCULATION OF TIME - unless otherwise specified, time periods within
         or following which any payment is to be made or act is to be done shall
         be calculated by excluding the day on which the period commences and
         including the day on which the period ends and by extending the period
         to the next Business Day following if the last day of the period is not
         a Business Day;

         BUSINESS DAY - whenever any payment is to be made or action to be taken
         under this Agreement is required to be made or taken on a day other
         than a Business Day, such payment shall be made or action taken on the
         next Business Day following such day; and

         INCLUSION - where the word "including" or "includes" appears in this
         Agreement, it means "including (or includes) without limitation".

Section 9.15 SCHEDULES

         The schedules to this Agreement, as listed below, are an integral part
of this Agreement:

<PAGE>   57
                                      -53-

Section 9.16 FURTHER ASSURANCES

         The Parties shall, with reasonable diligence, do all such things and
provide all such reasonable assurances as may be required to consummate the
transactions contemplated by this Agreement., and each Party shall provide such
further documents or instruments required by any other Party as may be
reasonably necessary or desirable to effect the purpose of this Agreement and
carry out its provisions, whether before or after the Closing.

         IN WITNESS WHEREOF, this Agreement has been duly executed by or on
behalf of each of the parties hereto as of the date first above written.

                                     WCS, INC.

                        [SEAL]
                                     Per: /s/ PATTI L. SCHMIGLE
                                         ---------------------------------------
                                         Patti L. Schmigle
                                         President

                                     WILLIAMS COMMUNICATIONS, LLC
                        [SEAL]
                                     Per: /s/ HOWARD E. JANZEN
                                         ---------------------------------------
                                         Howard E. Janzen
                                         President and CEO

                                     TELUS COMMUNICATIONS INC.

                                     Per: /s/ JAMES W. PETERS
                                         ---------------------------------------
                                         James W. Peters
                                         Executive Vice President, Corporate
                                         Development and General Counsel

<PAGE>   58
                                      -54-

                             EXHIBITS AND SCHEDULES

                           SCHEDULES: [TO BE PROVIDED]<PAGE>   1

                                                                   EXHIBIT 10.79

**** Confidential material has been omitted and filed separately with the
Securities and Exchange Commission.

                                OPTION AGREEMENT

            OPTION AGREEMENT, dated as of February 12, 2001 (this "Agreement"),
by and among Williams Communications, LLC, a Delaware limited liability company
("Williams Communications"), Williams International Telecom Limited, a Cayman
Islands company ("WITL"), and Telecom Americas, Ltd., a company incorporated
under the laws of Bermuda (or any of its successors or permitted assigns,
"Purchaser").

            WHEREAS, Purchaser and The Williams Communications Group, Inc., a
Delaware corporation ("Williams") are parties to the Funding Agreement, dated as
of even date hereof (the "Funding Agreement"), by and among Williams, Purchaser,
ATL-Algar Telecom Leste S.A., a sociedade anonima organized under the laws of
the Federative Republic of Brazil (the "Company"), and the other parties listed
therein;

            WHEREAS, Williams Communications desires to grant to Purchaser an
option to purchase all, but not less than all, of its shares of and equity
interests in (the "Williams International Shares") Williams International ATL
Limited, a Cayman Islands company ("Williams International"), which owns all but
one of the quotas of and equity interests in Johi Representacoes Ltda. ("Johi")
and, subject to the completion of certain transfers discussed below, all but one
of the quotas of and equity interests in Algar Administradora de Sistemas
Opticos Ltda. ("Opticos"), each a limited liability company organized under the
laws of the Federative Republic of Brazil;

            WHEREAS, WITL desires to grant to Purchaser's designee an option to
purchase the remaining quota of and equity interest in Johi and, subject to the
completion of certain transfers discussed below, the remaining quota of and
equity interest in Opticos owned by WITL (together with all of the Williams
International Shares, the "Option Shares"); and

            WHEREAS, it is a condition precedent to the obligations of Purchaser
under the Funding Agreement that the parties hereto execute and deliver this
Agreement.

            NOW, THEREFORE, in consideration of the premises and the mutual
agreements and covenants hereinafter set forth, the parties hereto hereby agree
as follows:

                                  DEFINITIONS

            SECTION 1.01. Certain Defined Terms. As used in this Agreement,
terms defined in the Funding Agreement shall have the same meaning as defined
therein, and, in addition, the underlined terms defined in quotations herein
shall have the meanings ascribed to such terms herein.

            "Business Day" means any day that is not a Saturday, Sunday or other
day on which banks or stock exchanges are required or authorized by Law to be
closed in the City of New York or London.

            "LIBOR" means the rate per annum at which U.S. Dollar deposits were
offered for a one-month period shown on the Reuters Screen as at 11:00 a.m.
(London time) two Business Days in London prior to the date of determination of
such rate for delivery on the date

<PAGE>   2

of determination of such rate. For this purpose the "Reuters Screen" means the
display designated as the LIBOR 01 page on the Reuters system or such other page
as may replace the LIBOR 01 page on that system for the purpose of displaying
offered rates for U.S. Dollars deposits.

            "Repurchase Exercise Date" means the later of March 31, 2002 and the
anniversary of the date that Purchaser informed Williams Communications of its
intention not to acquire the Option Shares pursuant to Section 3.05(a) or
3.05(b)(i) or (b)(iii) hereof.

            "Repurchase Interest" means 50% of the rights and obligations of
Purchaser under the Funding Agreement and 50% of any common shares of the
Company issued to Purchaser or its designated Subsidiary pursuant thereto, which
shall be free and clear of any Encumbrances (except in favor of Ericsson and the
Lenders under the Secured Loan Agreement).

            "Repurchase Price", as of the date of any repurchase pursuant to
Section 2.04 or Section 2.06, means (a)(i) U.S.$150 million less (ii) 50% of any
amounts repaid to Purchaser pursuant to Section 2(d) of the Funding Agreement,
plus (b) interest on such amount payable in arrears at the rate of LIBOR plus 5%
per annum accruing from the date the Contribution was made to the Repurchase
Closing Date (as defined in Section 2.04 hereof).

                                   ARTICLE II
                                GRANT OF OPTION

            SECTION 2.01. Grant of Option. Williams Communications and WITL
hereby grant to Purchaser an irrevocable option to purchase the Option Shares in
accordance with the terms and conditions set forth herein (the "Option").

            SECTION 2.02. Exercise of Option. Purchaser may exercise the Option
by delivering a written notice (the "Exercise Notice") to Williams
Communications on or before March 31, 2001 (the "Expiration Date").

            SECTION 2.03. Termination of Option. If Purchaser has not delivered
the Exercise Notice to Williams Communications on or before the Expiration Date,
the Option shall terminate.

            SECTION 2.04. Williams Communications' Repurchase Right. If the
Option or this Agreement terminates pursuant to Section 2.03 or 3.05(a) or (b)
hereof, Williams Communications (or its permitted assigns) shall have the right
at any time on or before the Repurchase Exercise Date to acquire the Repurchase
Interest for a price equal to the Repurchase Price. If Williams Communications
elects to exercise its right to acquire the Repurchase Interest, it shall notify
Purchaser in writing of its intention to do so and the date on which it will do
so (the "Repurchase Closing Date"), which shall be at least 30 days after the
date on which it gives notice but no later than March 31, 2002. Upon receipt of
such notice, Purchaser shall promptly send Williams Communications written
notice of the Repurchase Price and the account to which the Repurchase Price
shall be paid. On the Repurchase Closing Date, Williams Communications shall
have deposited in the account specified by Purchaser the Repurchase Price in
U.S. currency, in immediately payable funds, and the Purchaser shall deliver
such documents as shall be necessary to assign and transfer the Repurchase
Interest.

                                       2
<PAGE>   3

                                  ARTICLE III
                       PURCHASE AND SALE OF OPTION SHARES

            SECTION 3.01. Purchase and Sale. If Purchaser exercises the Option,
at the Closing (as defined below) Williams Communications and WITL shall sell,
assign, transfer, convey and deliver to Purchaser, and Purchaser shall purchase,
acquire, accept and take assignment and delivery of, from Williams
Communications and WITL, all of the right, title and interest of Williams
Communications and WITL in and to the Option Shares free and clear of any and
all Encumbrances. The aggregate purchase price in consideration of the Option
Shares shall be **** (the "Purchase Price") plus interest calculated pursuant
to Section 3.05(a)(ii) hereof, if applicable.

            SECTION 3.02. Closing Date. Except as hereinafter provided, the
closing of the purchase and sale of the Option Shares hereunder (the "Closing")
shall take place at the offices of Cleary, Gottlieb, Steen & Hamilton in New
York, New York, on the fifth Business Day following the date on which all of the
conditions contained in Section 3.03 have been satisfied or waived, as notified
by Purchaser or Williams Communications, as the case may be, or at such other
place and at such other time and date as may be mutually agreed upon by
Purchaser and Williams Communications. The date of the Closing is referred to in
this Agreement as the "Closing Date."

            SECTION 3.03. Conditions Precedent.

            (a) The obligation of Purchaser to consummate this Agreement and the
transactions contemplated hereby on the Closing Date shall be subject to the
satisfaction or waiver by Purchaser on such date of the following conditions:

                (i) Each of the representations and warranties made by Williams
     Communications and WITL hereunder shall be true and correct in all material
     respects as of the Closing Date with the same force and effect as though
     the same had been made as of the Closing Date.

                (ii) No Permit or waiver of, declaration or filing with or
     notification to any Person or Governmental Authority, including ANATEL, is
     required on the part of either party in connection with the transactions
     contemplated hereby other than such as have been given or made.

                (iii) Each of Williams Communications and WITL shall have
     performed and complied with in all material respects the covenants and
     provisions of this Agreement required to be performed or complied with by
     it between the date hereof and the Closing Date.

                (iv) No preliminary or permanent injunction or other
     Governmental Order of any court or tribunal or Governmental Authority of
     competent jurisdiction restraining, prohibiting or making illegal the
     consummation of the transactions contemplated hereby shall be in effect,
     threatened or pending.

     Redacted portions have been marked with asterisks (****). Confidential
     treatment has been requested for the redacted portions. The confidential
     redacted portions have been filed separately with the Securities and
     Exchange Commission.

                                       3
<PAGE>   4

            (b) The obligation of Williams Communications and WITL to consummate
this Agreement and the transactions contemplated hereby on the Closing Date
shall be subject solely to the satisfaction or waiver by Williams Communications
and WITL on such date of the following conditions:

                (i) Each of the representations and warranties made by Purchaser
     hereunder shall be true and correct in all material respects as of the
     Closing Date with the same force and effect as though the same had been
     made as of the Closing Date.

                (ii) No Permit or waiver of, declaration or filing with or
     notification to any Person or Governmental Authority, including ANATEL, is
     required on the part of either party in connection with the transactions
     contemplated hereby, other than such as have been given or made.

                (iii) Purchaser shall have performed and complied with in all
     material respects the covenants and provisions of this Agreement required
     to be performed or complied with by it between the date hereof and the
     Closing Date.

                (iv) No preliminary or permanent injunction or other
     Governmental Order of any court or tribunal or Governmental Authority of
     competent jurisdiction restraining, prohibiting or making illegal the
     consummation of the transactions contemplated hereby shall be in effect,
     threatened or pending.

                (v) Williams Communications shall have received the irrevocable
     written release of Ericsson of the obligations of The Williams Companies,
     Inc., a Delaware corporation (the "Sponsor"), howsoever arising, under the
     Amended and Restated Sponsor's Undertaking, dated as of September 15, 1999
     (the "Sponsor's Undertaking"), issued by the Sponsor in favor of the Agents
     and Lenders (as defined under the Secured Loan Agreement).

                (vi) Williams Communications shall have received the irrevocable
     written release of its future obligations, howsoever arising, under the
     Guaranty Agreement, dated as of November 9, 2000 (the "Unibanco Guaranty"),
     by Williams Communications in favor of Unibanco for the banks and other
     financial institutions from time to time party to the Contrato de Abertura
     de Credito Mediante Repasse, dated as of November 9, 2000, by and among the
     Company, Unibanco and such banks and financial institutions.

                (vii) Williams Communications shall have received the
     irrevocable written release of its future obligations, howsoever arising,
     under the Guaranty Agreement, dated as of November 9, 2000 (the "BNDES
     Guaranty"), by Williams Communications in favor of BNDES.

            SECTION 3.04. Closing Deliveries. At the Closing, each of the
parties hereto shall deliver, or shall cause to be delivered, to the other party
the following:

                (a) Williams Communications and WITL shall (and shall cause
     Williams International to) execute and deliver the amendments to the
     Articles of

                                       4
<PAGE>   5

Association of each of Johi and Opticos in form and substance acceptable to
Purchaser, transferring the quotas and equity interests in Johi and Opticos held
by WITL to an entity previously designated by Purchaser not less than 3 Business
Days prior to the Closing.

                (b) Williams Communications shall deliver to Purchaser the share
     register of Williams International duly amended by Williams International's
     registrar to show the transfer of the Williams International Shares to
     Purchaser, minute books and corporate seals of Williams International, and
     an amendment to the charter documents of Williams International effecting
     the change of name of Williams International to a name that does not
     contain the term "Williams", it being understood that Williams
     Communications shall effect the change of name to a name designated by
     Purchaser if Williams Communications receives Purchaser's selection not
     less than 3 Business Days' prior to the Closing.

                (c) Williams Communications shall deliver to Purchaser (i) the
     originals of the certificates of registration or a summary electronically
     issued by the Central Bank of Brazil evidencing all investments held by
     Williams International and WITL in the Capital Stock of the Company,
     Opticos and Johi, or (ii) documents that have been submitted to the Central
     Bank of Brazil that support the registration that will be issued by the
     Central Bank of Brazil.

                (d) Purchaser shall pay the Purchase Price to Williams
     Communications by transfer of immediately available funds to an account
     designated by Williams Communications, for itself and for the account of
     WITL, at least 3 Business Days prior to the Closing.

                (e) Each of the parties hereto shall receive any other
     certificates, legal opinions and documents required to be delivered by the
     parties hereunder.

            SECTION 3.05. Termination.

            (a) This Agreement may be terminated by the written agreement of
Purchaser and Williams Communications.

            (b) This Agreement shall terminate if the Purchaser has exercised
the Option and the Closing has not occurred within 60 days following the
Expiration Date; provided, however, that (i) upon mutual agreement, such 60-day
period may be extended for up to an additional 60 days in order to permit the
parties to fulfill the conditions precedent to Closing; (ii) if Williams
Communications or WITL has failed to satisfy its obligations under Section 4.03
hereof, at the option of Purchaser, such period shall be extended until the
earlier of the satisfaction of such requirement or the date that Purchaser
informs Williams Communications in writing of its intention not to purchase the
Option Shares; or (iii) if any Permit from (x) any Person, which is required
hereunder due to Williams Communications' or any of its Affiliates'
relationships (whether contractual or otherwise) with such Person (including,
but not limited to, the releases described in Sections 3.03(b)(v), (vi) and
(vii) hereof), or (y) ANATEL required in connection herewith (each, a "Critical
Permit") shall not have been obtained, such period shall be

                                       5
<PAGE>   6

extended until the earlier of the receipt of such Permit or the date that
Purchaser informs Williams Communications in writing of its intention not to
purchase the Option Shares.

            (c) Upon any extension of the Closing pursuant to Section 3.05(b)
above, interest shall accrue on the Purchase Price from and after the date that
is 60 days after the Expiration Date at a rate of LIBOR plus 5% per annum until
such amount has been received by Williams Communications, and such interest, if
any, shall be payable concurrently with the Purchase Price; provided, however,
that if such extension is due to a failure by the parties hereto to receive a
Critical Permit, then interest shall not begin to accrue until such Permit or
Permits have been obtained.

            (d) Upon any termination of this Agreement pursuant to Section
3.05(a) or (b), no party hereto shall thereafter have any further liability or
obligation hereunder except for liabilities resulting from any breach of this
Agreement; provided, however, that this Section 3.05, Section 4.02(e), Section
5.02, Section 5.11 and Section 5.12 shall each remain in full force and effect
and the parties hereto shall remain liable hereunder to the extent indicated
herein.

                                   ARTICLE IV
                   REPRESENTATIONS, WARRANTIES AND COVENANTS

            SECTION 4.01. Representations, Warranties and Covenants of Williams
Communications and WITL. Each of Williams Communications and WITL, jointly and
severally, represents, warrants and covenants as follows, both as of the date
hereof and as of the Closing Date:

            (a) Williams International is a Cayman Islands company duly
organized, validly existing and in good standing under the laws of the Cayman
Islands and has all requisite corporate power and authority to own, lease and
operate its properties and to carry on its business as it is now being
conducted. True, correct and complete copies of Williams International's
organizational documents, each as amended to the date of this Agreement, have
been made available to Purchaser.

            (b) WITL and Williams International own beneficially and of record
all of the issued and outstanding Capital Stock and Convertible Securities of
Johi and, subject to the transfer of the ownership interest of SK Telecom Co.,
Ltd., a company organized under the laws of the Republic of Korea, in SKTI-US,
LLC, a Delaware limited liability company, to Williams International and/or
WITL, Opticos free and clear of any and all Encumbrances, and Williams
International does not, directly or indirectly, (A) own, of record or
beneficially, any Capital Stock or Convertible Securities of any other Person
(other than the shares of the Company owned by Williams International) or (B)
control any other Person. Such Capital Stock and Convertible Securities have
been duly authorized and validly issued, are fully paid and nonassessable, and
were not issued in violation of the pre-emptive rights of any Person or of any
agreement, Law or regulation by which the issuer of such Capital Stock and
Convertible Securities at the time of issuance was bound. None of such Capital
Stock and Convertible Securities is subject to any option, warrant, call, right
of conversion, exchange or purchase, or any similar right, whether oral or
written, and there are no agreements or understandings

                                       6
<PAGE>   7

outstanding with respect to the voting or Transfer of any of such Capital Stock
and Convertible Securities.

            (c) The authorized capital stock of Williams International consists
of 50,000 shares of common stock, par value $1.00 per share, of which only the
Williams International Shares are issued and outstanding. The Williams
International Shares have been duly authorized and validly issued, are fully
paid and nonassessable, and were not issued in violation of the pre-emptive
rights of any Person or of any agreement, Law or regulation by which the issuer
of such shares at the time of issuance was bound. There are no outstanding
agreements which require Williams International to issue any Capital Stock or
Convertible Securities of Williams International. Williams Communications owns
the Williams International Shares free and clear of any Encumbrances. None of
the Williams International Shares is subject to any option, warrant, call, right
of conversion, exchange or purchase, or any similar right, whether oral or
written, and there are no agreements or understandings outstanding with respect
to the voting or Transfer of any of the Williams International Shares. The
delivery by Williams Communications to Purchaser at the Closing of the share
register of Williams International duly amended by Williams International's
registrar to show the transfer of the Williams International Shares to Purchaser
will vest Purchaser with good title to such shares, free and clear of any
Encumbrances.

            (d) Johi owns 43% of the preferred shares and 19% of the common
shares of the Company, and Williams International owns 22.5% of the preferred
shares of the Company (such shares, collectively, the "Company Shares"), free
and clear of any and all Encumbrances other than in favor of Ericsson and the
Lenders under the Secured Loan Agreement. Opticos owns the Promissory Note in
the amount of R$ 268,963,927.33 issued on December 29, 1999 by SBCI Brasil
Participacoes Ltda. free and clear of any and all Encumbrances . Johi owns all
of its rights under the AFACs free and clear of any and all Encumbrances other
than those in favor of Ericsson and the Lenders under the Secured Loan
Agreement. Except as set forth in any valid agreement among the shareholders of
the Company, none of the Company Shares is subject to any option, warrant, call,
right of conversion, exchange or purchase, or similar right, whether oral or
written, and there are no agreements or understandings outstanding with respect
to the voting or Transfer of any of the Company Shares.

            (e) Each of Williams International, Johi and Opticos was formed to
hold a direct or indirect interest in the Company and except for holding such
interests and the transactions related thereto, it has not engaged in any trade
or business or any other transaction, except certain other securities holdings
in other Persons by Williams International, which Williams International has
Transferred prior to the date hereof. Except as set forth in or referred to in
this Section 4.01, including certain rights in respect of SKTI-US, LLC and the
obligations of Williams International under the Credit Agreement, each of
Williams International, Johi and Opticos (A) does not have and has not had any
indebtedness, obligation or liability of any nature, whether accrued, absolute,
contingent or otherwise, whether due or becoming due, (B) is not and has not
been party to any agreement or arrangement with any other party, and (C) does
not have and has not had any real or personal property, tangible or intangible
right, or any other asset or right. Williams International, Johi and Opticos, as
the case may be, owns the assets set forth in this Section 4.01 free and clear
of any Encumbrances other than in favor of Ericsson and the Lenders under the
Secured Loan Agreement.

                                       7
<PAGE>   8

            (f) The investments held, and to be held on the Closing Date, by
Williams International and WITL in the Capital Stock and Convertible Securities
of Johi and Opticos, and by Williams International in the Capital Stock of the
Company, (i) are duly registered with the Central Bank of Brazil as a direct
foreign investment in accordance with applicable Laws or (ii) have been
submitted to the Central Bank of Brazil for registration as a direct foreign
investment, and Williams International and WITL have provided the Central Bank
of Brazil with all information necessary for the issuance of such registration
and is not aware of any fact or circumstance that would prevent such
registration from being issued.

            (g) Except with the prior written consent of the Purchaser, Williams
Communications shall not, and shall not permit Williams International to, (A)
change or amend the organizational documents of Williams International or its
Subsidiaries, except for the change in name referred to in Section 3.04(b)
above, (B) issue or Transfer any Capital Stock or Convertible Securities of
Williams International or its Subsidiaries, (C) directly or indirectly, make or
solicit the Transfer of, or assume any Encumbrance with respect to, any of the
Option Shares, (D) directly or indirectly, redeem, purchase or otherwise acquire
any of the Option Shares, (E) make, or agree to make, any dividend or
distribution to any of Williams International's stockholders or any of their
Affiliates, (F) acquire or dispose of any fixed assets or other properties or
assets of Williams International or its Subsidiaries, (G) subject to any new
Encumbrance any of Williams International's or its Subsidiaries' assets or
properties, (H) other than as required under applicable Law, grant any increase
in salary to any employee or officer of Williams International or its
Subsidiaries, if any, (I) enter into any employment agreement with any officer
or employee of Williams International or its Subsidiaries, if any, (J) dispose
of or diminish the voluntary reserve of Williams International or its
Subsidiaries, or (K) enter into any contract, agreement, commitment or
arrangement with respect to any of the foregoing, except as permitted hereby.

            (h) To the knowledge of Williams Communications, after due and
diligent inquiry and assuming completion of the Contribution in full under the
Funding Agreement, Williams Communications hereby represents and warrants that
there exists no obligation of (i) the Sponsor under the Sponsor's Undertaking;
and/or (ii) Williams Communications under the Unibanco Guaranty and/or the BNDES
Guaranty.

            SECTION 4.02. Representations, Warranties and Covenants of each of
the Parties. Each of the parties hereto severally represents, warrants and
covenants as follows, both as of the date hereof and as of the Closing Date:

            (a) It is duly organized and validly existing under the Laws of the
jurisdiction of its organization, and it has the power and authority and the
legal right to execute and deliver this Agreement and perform its obligations
hereunder, and has taken all necessary action to authorize its execution,
delivery and performance of this Agreement.

            (b) This Agreement has been duly executed and delivered by it and
constitutes its legal, valid and binding obligation, enforceable in accordance
with its terms, subject to the effects of bankruptcy, insolvency, fraudulent
conveyance, reorganization, moratorium and other similar Laws relating to or
affecting creditor's rights generally, and general equitable principles (whether
considered in a proceeding in equity or at Law).

                                       8
<PAGE>   9

            (c) The execution, delivery and performance of this Agreement by it
does not (i) violate, conflict with or result in the breach of any provision of
its organizational documents, (ii) conflict with or violate any Law or
Governmental Order applicable to it or any of its assets, properties or
businesses, or (iii) conflict with, result in any breach of, constitute a
default (or event which with the giving of notice or lapse of time, or both,
would become a default) under, require any consent under, or give to any other
Person any rights of termination, amendment, acceleration, suspension,
revocation or cancellation of rights of first refusal, rights of first offer,
change of control put, obligation to tender or other similar rights, or result
in the creation of any Encumbrance on any of its assets or properties pursuant
to, any note, bond, mortgage or indenture, contract, agreement, lease, sublease,
license, permit, franchise or other instrument or arrangement to which it is a
party or by which any of such assets or properties are bound or affected, which
would have a material adverse effect on its ability to consummate the
transactions contemplated by this Agreement.

            (d) To its knowledge, after due and diligent inquiry and except as
set forth in Article III above, no Permit or waiver of, declaration or filing
with or notification to any Person or Governmental Authority is required on the
part of such party in connection with the execution, delivery or performance of
this Agreement or the consummation of the transactions contemplated hereby.

            (e) It shall not hire or solicit for employment the employees of
the other party that are involved with the negotiations and the consummation of
the transactions contemplated hereby and by the Funding Agreement without the
prior written consent of such party.

            SECTION 4.03. Further Assurances. (a) Williams Communications shall,
and shall cause Williams International to, and WITL and Purchaser shall (i)
promptly take all such action as may be necessary, proper or advisable under
applicable Law for the consummation of the transactions contemplated hereby;
(ii) file and, if appropriate, use their or its best efforts to have declared
effective or approved all documents and notifications with, and to obtain any
consents of, all Governmental Authorities or other third parties that they or it
deem necessary or appropriate for the consummation of the transactions
contemplated hereby, including, without limitation, the consents, approvals and
waivers set forth in Article III; and (iii) give the other party information
requested by such other party pertaining to Williams International or Williams
Communications or WITL, in the case of requests by Purchaser, and Purchaser, in
the case of requests by Williams Communications or WITL, which is reasonably
necessary to enable such party or parties to take such actions and file in a
timely manner all documents and notifications required to be filed under
applicable Law.

            (b) If the Option is exercised, each of the parties shall execute
and deliver or cause to be executed and delivered all further documents and
instruments and use its reasonable best efforts to secure such Permits and take
all such further action as may be reasonably necessary in order (i) to
consummate the transactions contemplated hereby and (ii) to enable Purchaser to
exercise and enjoy all benefits and rights of Williams Communications and WITL
with respect to the Option Shares to be acquired upon such exercise of the
Option.

            SECTION 4.04. Survival and Indemnification. Each of the parties
hereto hereby agrees that the representations, warranties and covenants
contained in Sections 4.01 and

                                       9

<PAGE>   10

4.02 shall survive indefinitely. From and after the Closing Date, each party (an
"Indemnifying Party") agrees to indemnify fully, hold harmless, protect and
defend the other party and its Affiliates, and their respective directors,
officers, agents and employees, successors and assigns (the "Indemnified Party")
from and against: (i) any and all claims, demands, judgments, actions or causes
of action, liabilities, obligations, damages, losses, deficiencies, assessments,
costs, penalties, interest and expenses (including, without limitation, the
reasonable fees and expenses of counsel) (collectively, "Losses") incurred by
any of them arising out of, relating to or based upon any inaccuracy in, or
breach of, any of the representations or warranties of the Indemnifying Party
contained in Sections 4.01 or 4.02 hereof and (ii) any and all Losses incurred
by any of them arising out of, relating to or based upon any failure to perform,
or other breach of, any of the covenants or agreements of the Indemnifying Party
contained in Sections 4.01 or 4.02 hereof. The right of the Indemnified Party to
be indemnified hereunder shall not be limited or affected by any investigation
conducted or notice or knowledge obtained by it or on its behalf.

            SECTION 4.05. CADE Approval, Recission Rights. Each of Williams
Communications and WITL hereby acknowledges, covenants and agrees to use its
best efforts to cooperate in good faith with Purchaser to obtain any approval of
CADE required in connection with this Agreement or the Funding Agreement. If
such approval is denied or is granted subject to conditions that, in the
reasonable discretion of Purchaser, materially impair or detract from the value
of the Option Shares (each of the parties hereto hereby acknowledging that any
requirement imposed by CADE, other than as currently in effect under ANATEL
Resolution 101 or Decree No. 2056, of November 4, 1996 or any successor
regulations thereto, in connection with the granting of such approval that would
materially reduce the equity or voting interests in the Company that Purchaser
or any of its Affiliates would otherwise possess had such approval not been so
qualified would be a material impairment), then Williams Communications and
WITL, jointly and severally, hereby agree to repurchase the Option Shares at the
Purchase Price payable to the Purchaser in cash, in immediately available funds,
within 15 days of their receipt of a written notice from Purchaser stating that
CADE approval has been denied or that in Purchaser's reasonable discretion CADE
approval cannot be obtained without such an impairment or detraction.

                                   ARTICLE V
                                 MISCELLANEOUS

            SECTION 5.01. 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
borne by the party incurring such costs and expenses.

            SECTION 5.02. Notices. (a) All communications as they relate to this
Agreement shall be by facsimile or letter delivered by overnight or express mail
or courier. Each communication shall be made to the relevant party at the
facsimile number or address and marked for the attention of the Person(s) set
forth opposite such party's signature hereto unless specified otherwise in a
written notice by that party to the other parties for such purpose.

            (b) All communications delivered hereunder shall be in the English
language, and shall be deemed received (if by facsimile) when an acknowledgment
of receipt is received,

                                       10
<PAGE>   11

or (if by letter) when delivered, in each case in the manner required by this
Section 5.02; provided, that if a communication is received after business hours
it shall be deemed to be received and become effective on the next day which is
customarily considered a business day in the city to which such communication is
addressed. Once received, every communication shall be irrevocable except in
respect of any manifest error therein.

            SECTION 5.03. 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 5.04. Severability. If any term or other provision of this
Agreement is invalid, illegal or incapable of being enforced by any Law,
governmental regulation or public policy, all other terms and provisions of this
Agreement shall nevertheless remain in full force and effect as 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 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 5.05. 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 the parties with respect to the subject matter hereof.

            SECTION 5.06. Assignment.

            (a) No party hereto may assign this Agreement or any right or
obligation hereunder without the express written consent of the other parties
hereto (which consent may be granted or withheld at their sole discretion);
provided, that (i) Purchaser may assign this Agreement or any of its rights or
obligations hereunder to any of its Subsidiaries; provided, that, at the time of
any assignment to such Subsidiary, America Movil owns at least 20% of the voting
Capital Stock of Purchaser calculated on a fully-diluted basis; and (ii)
Williams Communications may assign this Agreement or any of its rights or
obligations hereunder if (A) Purchaser (or any of its successors or permitted
assigns) (x) fails to exercise the Option under the Option Agreement on or prior
to March 31, 2001, or (y) fails to purchase such Option Shares after having
exercised such Option, and (B) any such failure is not attributable to (x) the
absence or unavailability of any Permit despite the reasonable best efforts of
America Movil (or its successors and permitted assigns , as the case may be) to
obtain or assist in obtaining such Permit or (y) a breach by Williams
Communications or WITL of its obligations under Section 4.03 of the Option
Agreement.

            (b) Purchaser may assign the Option in whole or in part to any
Person without the consent of Williams Communications or WITL, provided,
however, that Purchaser shall retain all its obligations and other rights
hereunder unless they have been assigned pursuant to Section 5.06(a).

                                       11
<PAGE>   12

            SECTION 5.07. 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 successors and nothing herein, express or implied, is
intended to or shall confer upon any other Person or entity, any legal or
equitable right, benefit or remedy of any nature whatsoever under or by reason
of this Agreement.

            SECTION 5.08. Amendment. This Agreement may not be amended or
modified, except by an instrument in writing signed by, or on behalf of, each of
the parties bound by, or subject to the provision to be amended or modified.

            SECTION 5.09. Counterparts. This Agreement may be executed by the
parties hereto in any number of separate counterparts, and all of said
counterparts taken together shall be deemed to constitute one and the same
instrument.

            SECTION 5.10. Specific Performance. The parties hereto agree that
irreparable damage would occur in the event any provision of this Agreement was
not performed in accordance with the terms hereof and that the parties hereto
shall be entitled to specific performance of the terms hereof, in addition to
any other remedy at Law or in equity.

            SECTION 5.11. Governing Law. This Agreement shall be governed by,
and construed in accordance with, the Laws of the State of New York applicable
to contracts executed in and to be performed in that State without regard to
conflicts of law.

            SECTION 5.12. Waiver of Jury Trial. Each of the parties hereto
irrevocably and unconditionally waives trial by jury in any legal action or
proceeding relating to this Agreement or the transactions contemplated hereby
and for any counterclaim therein.

            SECTION 5.13. Arbitration. Any controversy, claim or dispute arising
out of or relating to or in connection with this Agreement including, without
limitation, any dispute regarding its breach, termination, enforceability or
validity hereof shall be finally settled in the manner set forth in Section 16
of the Shareholders Agreement.

                                       12
<PAGE>   13

            IN WITNESS WHEREOF, the undersigned has caused this Agreement to be
duly executed and delivered by its duly authorized representative in New York,
New York, United States of America, as of the day and year first above written.

                                     TELECOM AMERICAS, LTD.

                                     By:  /s/ DANIEL HAJJ ABOUMRAD
                                        ----------------------------------------
                                     Name:  Daniel Hajj Aboumrad
                                     Title: Director

                                     By:  /s/ LOUIS TANGUAY
                                        ----------------------------------------
                                     Name:  Louis Tanguay
                                     Title: Director

                              Address for Notices:
                              Telecom Americas, Ltd.
                              Cedar House
                              41 Cedar Avenue
                              Hamilton
                              HM 12
                              Bermuda
                              Phone: ++441-295-2244
                              Fax: ++441-292-8666
                              Attention: Secretary

<PAGE>   14

            IN WITNESS WHEREOF, the undersigned has caused this Agreement to be
duly executed and delivered by its duly authorized representative in New York,
New York, United States of America, as of the day and year first above written.

                                     WILLIAMS COMMUNICATIONS, LLC

                                     By:  /s/ RODNEY JAY SAILOR
                                        ----------------------------------------
                                     Name:  Rodney Jay Sailor
                                     Title: Attorney-in-Fact

                              Address for Notices:
                              Williams Communications, LLC
                              One Williams Center
                              Tulsa, OK 74172
                              Fax: 918-573-6216
                              Phone: 918-573-2148
                              Attention: Mr. Rod Sailor

<PAGE>   15

            IN WITNESS WHEREOF, the undersigned has caused this Agreement to be
duly executed and delivered by its duly authorized representative in New York,
New York, United States of America, as of the day and year first above written.

                                     WILLIAMS INTERNATIONAL TELECOM
                                     LIMITED

                                     By:  /s/ RODNEY JAY SAILOR
                                        ----------------------------------------
                                     Name:  Rodney Jay Sailor
                                     Title: Attorney-in-Fact

                              Address for Notices:
                              Williams International Telecom Limited
                              One Williams Center
                              Tulsa, OK 74172
                              Fax: 918-573-6216
                              Phone: 918-573-2148
                              Attention: Mr. Rod Sailor

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