<PAGE>   1


                                                                  Exhibit 10.4

                                                                  CONFORMED COPY







                                    FIVE YEAR

                                CREDIT AGREEMENT

                                   dated as of

                                 April 12, 2000


                                      among

                          Nortel Networks Corporation,

                             The Banks Party Hereto,

                                    including

                              Royal Bank of Canada
                                       and
                             Toronto Dominion Bank,
                            as Co-Syndication Agents,

                                       and

                               J.P. Morgan Canada,
                             as Administrative Agent

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

                                   Arranged by

                          J.P. Morgan Securities Inc.,
                              as Sole Lead Arranger
                                 and Bookrunner


<PAGE>   2

                                TABLE OF CONTENTS
                             ----------------------
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ARTICLE 1
  DEFINITIONS
  SECTION 1.01.  Definitions...................................................1
  SECTION 1.02.  Accounting Terms and Determinations..........................10
  SECTION 1.03.  Types of Borrowings..........................................10

ARTICLE 2
  THE CREDITS.
  SECTION 2.01.  Commitments to Lend..........................................11
  SECTION 2.02.  Notice of Committed Borrowing................................11
  SECTION 2.03.  Money Market Borrowings......................................12
  SECTION 2.04.  Notice to Banks; Funding of Loans............................16
  SECTION 2.05.  Notes........................................................17
  SECTION 2.06.  Maturity of Loans............................................18
  SECTION 2.07.  Interest Rates...............................................18
  SECTION 2.08.  Fees.........................................................20
  SECTION 2.09.  Optional Termination or Reduction of Commitments.............21
  SECTION 2.10.  Method of Electing Interest Rates............................21
  SECTION 2.11.  Optional Prepayments.........................................22
  SECTION 2.12.  General Provisions as to Payments............................22
  SECTION 2.13.  Funding Losses...............................................23
  SECTION 2.14.  Computation of Interest and Fees.............................23
  SECTION 2.15.  Interest Act Equivalency.....................................24
  SECTION 2.16.  Judgment Currency............................................24

ARTICLE 3
  CONDITIONS
  SECTION 3.01.  Closing......................................................25
  SECTION 3.02.  Borrowings...................................................25

ARTICLE 4
  REPRESENTATIONS AND WARRANTIES
  SECTION 4.01.  Corporate Existence and Power................................26
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  SECTION 4.02.  Corporate and Governmental Authorization;
           No Contravention...................................................26
  SECTION 4.03.  Binding Effect...............................................27
  SECTION 4.04.  Financial Information........................................27
  SECTION 4.05.  Litigation...................................................27

ARTICLE 5
  COVENANTS
  SECTION 5.01.  Information..................................................28
  SECTION 5.02.  Conduct of Business and Maintenance of Existence;
           Merger and Sales of Assets.........................................29
  SECTION 5.03.  Use of Proceeds..............................................30
  SECTION 5.04.  Negative Pledge..............................................30
  SECTION 5.05.  Minimum Consolidated Tangible Net Worth......................32

ARTICLE 6
  DEFAULTS
  SECTION 6.01.  Events of Default............................................32
  SECTION 6.02.  Notice of Default............................................33

ARTICLE 7
  THE AGENT AND THE CO-SYNDICATION AGENTS
  SECTION 7.01.  Appointment and Authorization................................34
  SECTION 7.02.  Agent and Affiliates.........................................34
  SECTION 7.03.  Action by Agent..............................................34
  SECTION 7.04.  Consultation with Experts....................................34
  SECTION 7.05.  Liability of Agent...........................................34
  SECTION 7.06.  Indemnification..............................................35
  SECTION 7.07.  Credit Decision..............................................35
  SECTION 7.08.  Successor Agent..............................................35
  SECTION 7.09.  Agent's Fee..................................................35
  SECTION 7.10.  Co-Syndication Agents........................................36

ARTICLE 8
  CHANGE IN CIRCUMSTANCES
  SECTION 8.01.  Basis for Determining Interest Rate Inadequate or Unfair.....36
  SECTION 8.02.  Illegality...................................................37
  SECTION 8.03.  Increased Cost and Reduced Return............................37
  SECTION 8.04.  Taxes........................................................39
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  SECTION 8.05.  Base Rate Loans Substituted for Affected Euro-Dollar Loans...41
  SECTION 8.06.  Substitution of Bank.........................................41

ARTICLE 9
  MISCELLANEOUS
  SECTION 9.01.  Notices......................................................41
  SECTION 9.02.  No Waivers...................................................42
  SECTION 9.03.  Expenses; Indemnification....................................42
  SECTION 9.04.  Sharing of Set-offs..........................................43
  SECTION 9.05.  Amendments and Waivers.......................................43
  SECTION 9.06.  Successors and Assigns.......................................43
  SECTION 9.07.  Collateral...................................................45
  SECTION 9.08.  Governing Law; Submission to Jurisdiction....................45
  SECTION 9.09.  Counterparts; Integration; Effectiveness.....................45
  SECTION 9.10.  WAIVER OF JURY TRIAL.........................................45
  SECTION 9.11.  Confidentiality..............................................46
  SECTION 9.12.  Termination of Existing Credit Agreements....................46


EXHIBIT A     -    Note

EXHIBIT B     -    Money Market Quote Request

EXHIBIT C     -    Invitation for Money Market Quotes

EXHIBIT D     -    Money Market Quote

EXHIBIT E     -    Opinion of Counsel for the Company

EXHIBIT F     -    Opinion of Special Counsel for the Administrative Agent

EXHIBIT G     -    Assignment and Assumption Agreement

EXHIBIT H     -    Extension Agreement
</TABLE>

<PAGE>   5

         AGREEMENT dated as of April 12, 2000 among NORTEL NETWORKS CORPORATION,
the BANKS party hereto, Royal Bank of Canada and Toronto Dominion Bank, as
Co-Syndication Agents, and J.P. MORGAN CANADA, as Administrative Agent.

         The parties hereto agree as follows:



                                    ARTICLE 1
                                   DEFINITIONS

         SECTION 1.01. Definitions. The following terms, as used herein, have
the following meanings:

         "Absolute Rate Auction" means a solicitation of Money Market Quotes
setting forth Money Market Absolute Rates pursuant to Section 2.03.

         "Administrative Questionnaire" means, with respect to each Bank, an
administrative questionnaire in the form prepared by the Agent and submitted to
the Agent (with a copy to the Company) duly completed by such Bank.

         "Affiliate" means, as to any Person, (i) any other Person (a
"Controlling Person") that directly, or indirectly through one or more
intermediaries, controls such Person or (ii) any Person (other than such Person
and its Subsidiaries) which is controlled by or is under common control with a
Controlling Person. As used herein, the term "control" means possession,
directly or indirectly, of the power to direct or cause the direction of the
management or policies of a Person, whether through the ownership of voting
securities, by contract or otherwise.

         "Agent" means J.P. Morgan Canada in its capacity as administrative
agent for the Banks hereunder, and its successors in such capacity.

         "Applicable Lending Office" means, with respect to any Bank, (i) in the
case of its Base Rate Loans, its Domestic Lending Office, (ii) in the case of
its Euro-Dollar Loans, its Euro-Dollar Lending Office and (iii) in the case of
its Money Market Loans, its Money Market Lending Office.

         "Assignee" has the meaning set forth in Section 9.06(c).

         "Attributable Debt" in respect of a Financing Lease means the present
value of the obligations of the lessee thereunder for rental payments during the
remaining term of such lease.

         "Bank" means each bank listed on the signature pages hereof, each
Assignee which becomes a Bank pursuant to Section 9.06(c), and their respective
successors.

         "Base Rate" means the annual rate of interest announced from time to
time by J.P. Morgan Canada as being its reference rate then in effect for
determining interest rates on commercial loans in U.S. Dollars made in Canada by
J.P. Morgan Canada.

         "Base Rate Loan" means a Committed Loan to be made by a Bank as a Base

<PAGE>   6

Rate Loan in accordance with the applicable Notice of Committed Borrowing or
Notice of Interest Rate Election or pursuant to Article 8.

         "Borrowing" has the meaning set forth in Section 1.03.

         "Canadian Dollars" and the sign "C$" mean lawful money of Canada.

         "Canadian Prime Rate" means the annual rate of interest announced from
time to time by J.P. Morgan Canada as being its reference rate then in effect
for determining interest rates on commercial loans in Canadian Dollars made in
Canada by J.P. Morgan Canada.

         "Change of Control" means (x) any person or group of persons (within
the meaning of Section 13 or 14 of the Securities Exchange Act of 1934, as
amended) (other than, prior to implementation of the Plan of Arrangement, BCE,
Inc. and its Affiliates (taken as a group) and, after implementation of the Plan
of Arrangement, Holdco) shall acquire beneficial ownership (within the meaning
of Rule 13d-3 promulgated by the Securities and Exchange Commission under said
Act) of 40% or more of the outstanding shares of common stock of the Relevant
Entity or (y) during any period of twelve consecutive calendar months ending
before or beginning after implementation of the Plan of Arrangement, individuals
who were directors of the Relevant Entity on the first day of such period (or
who were nominated for election or appointed by such directors as a director of
the Relevant Entity) shall cease to constitute a majority of the Relevant
Entity's board of directors.

         For purposes of this definition, "Plan of Arrangement" means the plan
whereby BCE, Inc. shall distribute indirectly an approximately 36% ownership
interest in the Company to the shareholders of BCE, Inc. in the form of common
shares of Holdco; "Holdco" means the new publicly traded Canadian corporation
which will own all of the common shares of the Company and any successor
thereto; and "Relevant Entity" means (i) before implementation of the Plan of
Arrangement, the Company, and (ii) after implementation of the Plan of
Arrangement, each of the Company and Holdco.

         "Closing Date" means the date on or after the Effective Date on which
the Agent shall have received the documents specified in or pursuant to Section
3.01.

         "Co-Syndication Agents" means Royal Bank of Canada and Toronto Dominion
Bank, in their capacity as co-syndication agents.

         "Commitment" means, with respect to each Bank, the amount set forth
opposite the name of such Bank on the signature pages hereof, as such amount may
be reduced from time to time pursuant to Section 2.09.

         "Committed Loan" means a loan made by a Bank pursuant to Section 2.01;
provided that if any such loan or loans are combined or subdivided pursuant to a
Notice of Interest Rate Election, the term "Committed Loan" shall refer to the
combined principal amount resulting from such combination or to each of the
separate principal amounts resulting from such subdivision, as the case may be.

         "Company" means Nortel Networks Corporation, a Canadian corporation,
and its successors.

         "Company's 1999 Form 10-K" means the Company's annual report on Form
10-K for 1999, as filed with the Securities and Exchange Commission pursuant to

<PAGE>   7

the Securities Exchange Act of 1934.

         "Consolidated Subsidiary" means at any date any Subsidiary or other
entity the accounts of which would be consolidated with those of the Company in
its consolidated financial statements if such statements were prepared as of
such date.

         "Consolidated Net Tangible Assets" means the total amount of assets
after deducting therefrom (i) all current liabilities, and (ii) all goodwill,
tradenames, trademarks, patents, unamortized debt discount and expense and other
like intangible assets, all as shown in the most recent annual or quarterly
consolidated balance sheet of the Company (which may be contained in the
Company's then most recent annual or quarterly report on Form 10-K or Form 10-Q,
as applicable, as filed with the Securities and Exchange Commission); assets
shall include an amount equal to the Attributable Debt in respect of those
Financing Leases not capitalized on such balance sheet.

         "Consolidated Tangible Net Worth" means at any date the consolidated
stockholders' equity of the Company and its Consolidated Subsidiaries less their
consolidated Intangible Assets, all determined as of such date. For purposes of
this definition, "Intangible Assets" means the amount (to the extent reflected
in determining such consolidated stockholders' equity) of goodwill, patents,
trademarks, service marks, tradenames, copyrights and other intangible assets.

         "Default" means any condition or event which constitutes an Event of
Default or which with the giving of notice or lapse of time or both would,
unless cured or waived, become an Event of Default.

         "Domestic Business Day" means any day except a Saturday, Sunday or
other day on which commercial banks in Toronto are required or authorized by law
to close.

         "Domestic Lending Office" means, as to each Bank, its office located at
its address set forth in its Administrative Questionnaire (or identified in its
Administrative Questionnaire as its Domestic Lending Office) or such other
office as such Bank may hereafter designate as its Domestic Lending Office by
notice to the Company and the Agent.

         "Effective Date" means the date this Agreement becomes effective in
accordance with Section 9.09.

         "Euro-Currency Business Day" means, where the funds are to be paid or
made available in U.S. Dollars or Canadian Dollars, any Domestic Business Day on
which commercial banks are open for international business (including dealings
in U.S. Dollar deposits or Canadian Dollar deposits, as the case may be) in
London.

         "Euro-Dollar Lending Office" means, as to each Bank, its office, branch
or affiliate located at its address set forth in its Administrative
Questionnaire (or identified in its Administrative Questionnaire as its
Euro-Dollar Lending Office) or such other office, branch or affiliate of such
Bank as it may hereafter designate as its Euro-Dollar Lending Office by notice
to the Company and the Agent.

         "Euro-Dollar Loan" means a Committed Loan to be made by a Bank as a
Euro-Dollar Loan in accordance with the applicable Notice of Committed Borrowing
or Notice of Interest Rate Election.
<PAGE>   8

         "Euro-Dollar Margin" means a rate per annum determined in accordance
with the Pricing Schedule.

         "Event of Default" has the meaning set forth in Section 6.01.

         "Executive Officer" means any of the Chairman of the Board of
Directors, the President and Chief Executive Officer, the Chief Financial
Officer, the Treasurer, the Assistant Treasurer or the Controller of the
Company.

         "Existing Credit Agreements" means the Credit Agreements dated as of
April 26, 1995, as amended, among the Company, the banks listed on the signature
pages thereof and J.P. Morgan Canada, as Agent.

         "Financing Leases" means sale and leaseback transactions, except for:
(i) temporary leases for a term, including any renewal thereof, of not more than
three years; (ii) leases between the Company and NNI or between NNI and the
Company; and (iii) leases for properties executed within one year of the latest
of acquisition, completion of construction and commencement of commercial
operation thereof.

         "Fixed Rate Loans" means Euro-Dollar Loans or Money Market Loans
(excluding Money Market LIBOR Loans bearing interest at the Base Rate pursuant
to Section 8.01) or both.

         "Funded Debt" means any indebtedness for borrowed money, whether of the
Company or of a third person.

         "Group of Loans" means at any time a group of Loans consisting of (i)
all Committed Loans which are Base Rate Loans at such time or (ii) all Committed
Loans which are Euro-Dollar Loans having the same Interest Period at such time;
provided that if a Committed Loan of any particular Bank is converted to or made
as a Base Rate Loan pursuant to Section 8.02 or 8.05, such Loan shall be
included in the same Group or Groups of Loans from time to time as it would have
been in if it had not been so converted or made.

         "Indemnitee" has the meaning set forth in Section 9.03(b).

         "Interest Period" means: (1) with respect to each Euro-Dollar Loan, the
period commencing on the date of borrowing specified in the applicable Notice of
Borrowing or Notice of Interest Rate Election and ending one, two, three or six
months thereafter, as the Company may elect in the applicable notice; provided
that:

         (a) any Interest Period which would otherwise end on a day which is not
         a Euro-Currency Business Day shall be extended to the next succeeding
         Euro-Currency Business Day unless such Euro-Currency Business Day falls
         in another calendar month, in which case such Interest Period shall end
         on the next preceding Euro-Currency Business Day;

         (b) any Interest Period which begins on the last Euro-Currency Business
         Day of a calendar month (or on a day for which there is no numerically
         corresponding day in the calendar month at the end of such Interest
         Period) shall, subject to clause (c) below, end on the last
         Euro-Currency Business Day of a calendar month; and
<PAGE>   9

         (c) any Interest Period beginning prior to the Termination Date which
         would otherwise end after the Termination Date shall end on the
         Termination Date.

(2) with respect to each Money Market LIBOR Loan, the period commencing on the
date of such borrowing specified in the applicable Notice of Borrowing and
ending such whole number of months thereafter as the Company may elect in
accordance with Section 2.03; provided that:


         (a) any Interest Period which would otherwise end on a day which is not
         a Euro-Currency Business Day shall be extended to the next succeeding
         Euro-Currency Business Day unless such Euro-Currency Business Day falls
         in another calendar month, in which case such Interest Period shall end
         on the next preceding Euro-Currency Business Day;

         (b) any Interest Period which begins on the last Euro-Currency Business
         Day of a calendar month (or on a day for which there is no numerically
         corresponding day in the calendar month at the end of such Interest
         Period) shall, subject to clause (c) below, end on the last
         Euro-Currency Business Day of a calendar month; and

         (c) any Interest Period which would otherwise end after the Termination
         Date shall end on the Termination Date.

(3) with respect to each Money Market Absolute Rate Loan, the period commencing
on the date of borrowing specified in the applicable Notice of Borrowing and
ending such number of days thereafter (but not less than 14 days) as the Company
may elect in accordance with Section 2.03; provided that:

         (a) any Interest Period which would otherwise end on a day which is not
         a Euro-Currency Business Day shall be extended to the next succeeding
         Euro-Currency Business Day; and

         (b) any Interest Period which would otherwise end after the Termination
         Date shall end on the Termination Date.

         "LIBOR Auction" means a solicitation of Money Market Quotes setting
forth Money Market Margins based on the London Interbank Offered Rate pursuant
to Section 2.03.

         "Loan" means a Base Rate Loan, a Euro-Dollar Loan or a Money Market
Loan and "Loans" means Base Rate Loans, Euro-Dollar Loans or Money Market Loans
or any combination of the foregoing.

         "London Interbank Offered Rate" has the meaning set forth in Section
2.07(b).

         "Material Subsidiary" means any Subsidiary (x) the consolidated
revenues of which equal or exceed 10% of the revenues of the Company and its
Consolidated Subsidiaries on a consolidated basis or (y) the consolidated assets
of which equal or exceed 10% of the assets of the Company and its Consolidated
Subsidiaries on a consolidated basis, in each case as contained in the most
recent annual report on Form 10-K, as filed with the Securities and Exchange
Commission.

         "Money Market Absolute Rate" has the meaning set forth in Section

<PAGE>   10

2.03(d)(ii)(D).

         "Money Market Absolute Rate Loan" means a loan to be made by a Bank
pursuant to an Absolute Rate Auction.

         "Money Market Lending Office" means, as to each Bank, its Domestic
Lending Office or such other office, branch or affiliate of such Bank as it may
hereafter designate as its Money Market Lending Office by notice to the Company
and the Agent; provided that any Bank may from time to time by notice to the
Company and the Agent designate separate Money Market Lending Offices for its
Money Market LIBOR Loans, on the one hand, and its Money Market Absolute Rate
Loans, on the other hand, in which case all references herein to the Money
Market Lending Office of such Bank shall be deemed to refer to either or both of
such offices, as the context may require.

         "Money Market LIBOR Loan" means a loan to be made by a Bank pursuant to
a LIBOR Auction (including such a loan bearing interest at the Base Rate or the
Canadian Prime Rate, as the case may be, pursuant to Section 8.01).

         "Money Market Loan" means a Money Market LIBOR Loan or a Money Market
Absolute Rate Loan.

         "Money Market Margin" has the meaning set forth in Section
2.03(d)(ii)(C).

         "Money Market Quote" means an offer by a Bank to make a Money Market
Loan in accordance with Section 2.03.

         "Mortgage" means and includes any mortgage, hypothec, pledge, lien,
security interest, privilege, floating charge, conditional sale or other title
retention agreement or other similar encumbrance securing indebtedness for
borrowed money.

         "Notes" means promissory notes of the Company, substantially in the
form of Exhibit A hereto, evidencing the obligation of the Company to repay the
Loans made to it, and "Note" means any one of such promissory notes issued
hereunder.

         "Notice of Borrowing" means a Notice of Committed Borrowing (as defined
in Section 2.02) or a Notice of Money Market Borrowing (as defined in Section
2.03(f)).

         "Notice of Interest Rate Election" has the meaning set forth in Section
2.10(a).

         "NNI" means Nortel Networks Inc., a Delaware corporation, and its
successors.

         "Parent" means, with respect to any Bank, any Person controlling such
Bank.

         "Participant" has the meaning set forth in Section 9.06(b).

         "Person" means an individual, a corporation, a partnership, an
association, a trust or any other entity or organization, including a government
or political subdivision or an agency or instrumentality thereof.
<PAGE>   11

         "Pricing Schedule" means the schedule attached hereto identified as
such.

         "Purchase Money Mortgage" means a mortgage on property existing at the
time of acquisition thereof by the Company or NNI; any mortgage on any property
acquired, constructed or improved by the Company or NNI incurred after the
Effective Date which is created or assumed contemporaneously with, or within 180
days after, such acquisition, or completion of such construction or improvement,
to secure or provide for the payment of the purchase price thereof or the cost
of construction or improvement thereon incurred after the Effective Date
(including the cost of any underlying real property); provided, however, that in
the case of any such acquisition, construction or improvement, the Mortgage
shall not apply to any property previously owned by the Company or NNI, other
than, in the case of any such construction or improvement, any real property,
theretofore substantially unimproved for the purposes of the Company or NNI, on
which the property so constructed, or the improvement, is located and other than
any machinery or equipment installed at any time so as to constitute immovable
property or a fixture on the real property on which the property so constructed,
or the improvement, is located.

         "Reference Banks" means the principal London offices of Citibank, N.A.,
Bank of America, N.A., and Morgan Guaranty Trust Company of New York, and
"Reference Bank" means any one of such Reference Banks.

         "Regulation U" means Regulation U of the Board of Governors of the
Federal Reserve System, as in effect from time to time.

         "Required Banks" means at any time Banks having at least 51% of the
aggregate amount of the Commitments or, if the Commitments shall have been
terminated, holding Notes evidencing at least 51% of the aggregate unpaid
principal amount of the Loans.

         "Required Banks (80%)" means at any time Banks having at least 80% of
the aggregate amount of the Commitments or, in the case of Section 7.08, if the
Commitments shall have been terminated, holding Notes evidencing at least 80% of
the aggregate unpaid principal amount of the Loans.

         "Revolving Credit Period" means, with respect to any Bank, the period
from and including the Closing Date to but excluding the Termination Date of
such Bank.

         "Subsidiary" means, as to any Person, any corporation or other entity
of which securities or other ownership interests having ordinary voting power to
elect a majority of the board of directors or other persons performing similar
functions are at the time directly or indirectly owned by such Person; unless
otherwise specified, "Subsidiary" means a Subsidiary of the Company.

         "Termination Date" means, with respect to any Bank, April 15, 2005 or
such later date to which the Termination Date of such Bank shall have been
extended pursuant to Section 2.01(b), or, if such day is not a Euro-Currency
Business Day, the next succeeding Euro-Currency Business Day unless such
Euro-Currency Business Day falls in another calendar month, in which case the
Termination Date shall be the next preceding Euro-Currency Business Day.

         "United States" means the United States of America, including the
States and the District of Columbia, but excluding its territories and
possessions.
<PAGE>   12

         "U.S. Dollars" and the sign "$" mean lawful money of the United States.

         SECTION 1.02. Accounting Terms and Determinations. Unless otherwise
specified herein, all accounting terms used herein shall be interpreted, all
accounting determinations hereunder shall be made, and all financial statements
required to be delivered hereunder shall be prepared in accordance with
generally accepted accounting principles as in effect from time to time in the
United States, applied on a basis consistent (except for changes concurred in by
the Company's independent public accountants) with the most recent audited
consolidated financial statements of the Company and its Consolidated
Subsidiaries delivered to the Banks; provided that, if the Company notifies the
Agent that the Company wishes to amend any covenant in Article 5 to eliminate
the effect of any change in such generally accepted accounting principles on the
operation of such covenant (or if the Agent notifies the Company that the
Required Banks wish to amend Article 5 for such purpose), then the Company's
compliance with such covenant shall be determined on the basis of generally
accepted accounting principles in effect in the United States immediately before
the relevant change in generally accepted accounting principles became
effective, until either such notice is withdrawn or such covenant is amended in
a manner satisfactory to the Company and the Required Banks.

         SECTION 1.03. Types of Borrowings. The term "Borrowing" denotes the
aggregation of Loans of one or more Banks to be made to the Company pursuant to
Article 2 on a single date and in a single currency, all of which Loans are of
the same type (subject to Article 8) and, except in the case of Base Rate Loans,
have the same Interest Period or initial Interest Period. Borrowings are
classified for purposes of this Agreement either by reference to the pricing of
Loans comprising such Borrowing (e.g., a "Fixed Rate Borrowing" is a Euro-Dollar
Borrowing or a Money Market Borrowing (excluding any such Borrowing consisting
of Money Market LIBOR Loans bearing interest at the Base Rate pursuant to
Section 8.01), and a "Euro-Dollar Borrowing" is a Borrowing comprised of
Euro-Dollar Loans) or by reference to the provisions of Article 2 under which
participation therein is determined (i.e., a "Committed Borrowing" is a
Borrowing under Section 2.01 in which all Banks participate in proportion to
their Commitments, while a "Money Market Borrowing" is a Borrowing under Section
2.03 in which the Bank participants are determined on the basis of their bids in
accordance therewith).


                                    ARTICLE 2
                                   THE CREDITS

         SECTION 2.01. Commitments to Lend. (a) Revolving Loans. During the
Revolving Credit Period, each Bank severally agrees, on the terms and conditions
set forth in this Agreement, to make loans to the Company pursuant to this
subsection (a) from time to time in amounts such that the aggregate principal
amount of Committed Loans by such Bank at any one time outstanding shall not
exceed the amount of its Commitment. Each Borrowing under this subsection (a)
shall be in an aggregate principal amount of $25,000,000 or any larger multiple
of $5,000,000 (except that any such Borrowing may be in the aggregate amount
available subject to Section 3.02(c)), and shall be made from the several Banks
ratably in proportion to their respective Commitments. Within the foregoing
limits, the Company may borrow under this subsection (a), repay or, to the
extent permitted by Section 2.11, prepay Loans and reborrow at any time during
the Revolving Credit Period under this subsection (a). The Commitments shall
terminate at the close of business on the Termination Date.
<PAGE>   13

          (b) Extension of Termination Date. The Termination Date may be
extended, in the manner set forth in this subsection 2.01(b), on each of April
15, 2005 and the first anniversary of such date (an "Extension Date") for a
period of one year after the date on which the Termination Date would otherwise
have expired. If the Company wishes to request an extension of the Termination
Date on any Extension Date, it shall give written notice to that effect to the
Agent not less than 60 nor more than 90 days prior to such Extension Date,
whereupon the Agent shall notify each of the Banks of such notice. Each Bank
will use its best efforts to respond to such request, whether affirmatively or
negatively, within 30 days. If the Required Banks (80%) respond affirmatively,
then, subject to receipt by the Agent prior to such Extension Date of
counterparts of an Extension Agreement in substantially the form of Exhibit H
duly completed and signed by all of the parties hereto (other than any Bank that
has not responded affirmatively to such request), the Termination Date shall be
extended, effective on such Extension Date, for a period of one year to the date
stated in such Extension Agreement (except that the Commitment of any Bank that
is not a party to such Extension Agreement shall terminate in its entirety on
such Extension Date, and thereafter such Bank shall cease to be a "Bank" party
to this Agreement; provided that the provisions of Sections 8.03 (but only with
respect to compensation claimed no later than 180 days after such Extension
Date), 8.04 and 9.03 shall continue to inure to the benefit of such Bank).

         SECTION 2.02. Notice of Committed Borrowing. The Company shall give the
Agent notice (a "Notice of Committed Borrowing") not later than (x) 10:45 A.M.
(Toronto time) on the date of each Base Rate Borrowing and (y) 1:00 P.M.
(Toronto time) on the third Euro-Currency Business Day before each Euro-Dollar
Borrowing, specifying:

               (i) the date of such Borrowing, which shall be a Domestic
         Business Day in the case of a Base Rate Borrowing or a Euro-Currency
         Business Day in the case of a Euro-Dollar Borrowing;

               (ii) the aggregate amount of such Borrowing;

               (iii) whether the Loans comprising such Borrowing bear interest
         initially at the Base Rate or at a Euro-Dollar Rate; and

               (iv) in the case of a Euro-Dollar Borrowing, the duration of the
         initial Interest Period applicable thereto, subject to the provisions
         of the definition of Interest Period.

Notwithstanding the foregoing, no more than eleven Euro-Dollar Borrowings shall
be outstanding at any one time, and any Borrowing which would exceed such
limitation shall be made as a Base Rate Borrowing.

         SECTION 2.03. Money Market Borrowings. (a) The Money Market Option. In
addition to Committed Borrowings pursuant to Section 2.01(a), the Company may,
as set forth in this Section, request the Banks during the Revolving Credit
Period to make offers to make Money Market Loans to the Company. The Banks may,
but shall have no obligation to, make such offers and the Company may, but shall
have no obligation to, accept any such offers in the manner set forth in this
Section. The making of a Money Market Loan by a Bank shall not affect its or any
other Bank's obligation to make Committed Loans pursuant to Section 2.01.

          (b) Money Market Quote Request. When the Company wishes to request
offers to make Money Market Loans under this Section, it shall transmit to the

<PAGE>   14

Agent by telex or facsimile transmission a Money Market Quote Request
substantially in the form of Exhibit B hereto so as to be received not later
than 10:30 A.M. (Toronto time) on (x) the fourth Euro-Currency Business Day
prior to the date of Borrowing proposed therein, in the case of a LIBOR Auction
or (y) the Domestic Business Day next preceding the date of Borrowing proposed
therein, in the case of an Absolute Rate Auction (or, in either case, such other
time or date as the Company and the Agent shall have mutually agreed and shall
have notified to the Banks not later than the date of the Money Market Quote
Request for the first LIBOR Auction or Absolute Rate Auction for which such
change is to be effective) specifying:

               (i) the proposed date of Borrowing, which shall be a
         Euro-Currency Business Day in the case of a LIBOR Auction or a Domestic
         Business Day in the case of an Absolute Rate Auction,

               (ii) the currency of such Borrowing, which shall be either U.S.
         Dollars or Canadian Dollars,

               (iii) the aggregate amount of such Borrowing, which shall be
         $25,000,000 or C$25,000,000, as the case may be, or a larger multiple
         of $5,000,000 or C$5,000,000, as the case may be,

               (iv) the duration of the Interest Period applicable thereto,
         subject to the provisions of the definition of Interest Period, and

               (v) whether the Money Market Quotes requested are to set forth a
         Money Market Margin or a Money Market Absolute Rate.

The Company may request offers to make Money Market Loans for more than one
Interest Period in a single Money Market Quote Request. No Money Market Quote
Request shall be given within two Euro-Currency Business Days (or such other
number of days as the Company and the Agent may agree) of any other Money Market
Quote Request.

          (c) Invitation for Money Market Quotes. Promptly upon (and in any
event not later than 12:00 Noon (Toronto time) on the date of) receipt of a
Money Market Quote Request submitted in accordance with subsection (b), the
Agent shall send to the Banks by telex or facsimile transmission an Invitation
for Money Market Quotes substantially in the form of Exhibit C hereto, which
shall constitute an invitation by the Company to each Bank to submit Money
Market Quotes offering to make the Money Market Loans to which such Money Market
Quote Request relates in accordance with this Section.

         (d) Submission and Contents of Money Market Quotes. (i) Each Bank may
submit a Money Market Quote containing an offer or offers to make Money Market
Loans in response to any Invitation for Money Market Quotes. Each Money Market
Quote must comply with the requirements of this subsection (d) and must be
submitted to the Agent by telex or facsimile transmission at its offices
specified in or pursuant to Section 9.01 not later than (x) 10:00 A.M. (Toronto
time) on the third Euro-Currency Business Day prior to the proposed date of
Borrowing, in the case of a LIBOR Auction or (y) 9:30 A.M. (Toronto time) on the
proposed date of Borrowing, in the case of an Absolute Rate Auction (or, in
either case, such other time or date as the Company and the Agent shall have
mutually agreed and shall have notified to the Banks not later than the date of
the Money Market Quote Request for the first LIBOR Auction or Absolute Rate
Auction for which such change is to be effective); provided that Money Market
Quotes submitted by the Agent (or any affiliate of the Agent) in the capacity of

<PAGE>   15

a Bank may be submitted, and may only be submitted, if the Agent or such
affiliate notifies the Company of the terms of the offer or offers contained
therein not later than (x) one hour prior to the deadline for the other Banks,
in the case of a LIBOR Auction or (y) 15 minutes prior to the deadline for the
other Banks, in the case of an Absolute Rate Auction. Subject to Articles 3 and
6, any Money Market Quote so made shall be irrevocable except with the written
consent of the Agent given on the instructions of the Company.

               (ii) Each Money Market Quote shall be in substantially the form
         of Exhibit D hereto and shall in any case specify:

                  (A) the proposed date of Borrowing and the currency of such
               Borrowing,

                  (B) the principal amount of the Money Market Loan for which
               each such offer is being made, which principal amount (w) may be
               greater than or less than the Commitment (or the equivalent
               amount in Canadian Dollars) of the quoting Bank, (x) must be
               $5,000,000 or C$5,000,000, as the case may be, or a larger
               multiple of $1,000,000 or C$1,000,000, as the case may be, (y)
               may not exceed the principal amount of Money Market Loans for
               which offers were requested and (z) may be subject to an
               aggregate limitation as to the principal amount of Money Market
               Loans for which offers being made by such quoting Bank may be
               accepted,

                  (C) in the case of a LIBOR Auction, the margin above or below
               the applicable London Interbank Offered Rate (the "Money Market
               Margin") offered for each such Money Market Loan, expressed as a
               percentage (specified to the nearest 1/10,000th of 1%) to be
               added to or subtracted from such base rate,

                  (D) in the case of an Absolute Rate Auction, the rate of
               interest per annum (specified to the nearest 1/10,000th of 1%)
               (the "Money Market Absolute Rate") offered for each such Money
               Market Loan, and

                  (E) the identity of the quoting Bank.

A Money Market Quote may set forth up to five separate offers by the quoting
Bank with respect to each Interest Period specified in the related Invitation
for Money Market Quotes.

               (iii) Any Money Market Quote shall be disregarded if it:

                  (A) is not substantially in conformity with Exhibit D hereto
               or does not specify all of the information required by subsection
               (d)(ii);

                  (B) contains qualifying, conditional or similar language;

                  (C) proposes terms other than or in addition to those set
               forth in the applicable Invitation for Money Market Quotes; or

                  (D) arrives after the time set forth in subsection (d)(i).

         (e) Notice to Company. The Agent shall promptly (x) and in any event

<PAGE>   16

not later than 10:45 A.M. (Toronto time), in the case of a LIBOR Auction, or
10:00 A.M. (Toronto time), in the case of an Absolute Rate Auction, on the date
of receipt notify the Company of the terms of any Money Market Quote submitted
by a Bank that is in accordance with subsection (d) and (y) notify the Company
of the terms of any Money Market Quote that amends, modifies or is otherwise
inconsistent with a previous Money Market Quote submitted by such Bank with
respect to the same Money Market Quote Request. Any such subsequent Money Market
Quote shall be disregarded by the Agent unless such subsequent Money Market
Quote is submitted solely to correct a manifest error in such former Money
Market Quote. The Agent's notice to the Company shall specify (A) the aggregate
principal amount and currency of Money Market Loans for which offers have been
received for each Interest Period specified in the related Money Market Quote
Request, (B) the respective principal amounts and Money Market Margins or Money
Market Absolute Rates, as the case may be, so offered and (C) if applicable,
limitations on the aggregate principal amount of Money Market Loans for which
offers in any single Money Market Quote may be accepted.

         (f) Acceptance and Notice by Company. Not later than (x) 11:30 A.M.
(Toronto time) on the third Euro-Currency Business Day prior to the proposed
date of Borrowing, in the case of a LIBOR Auction or (y) 10:45 A.M. (Toronto
time) on the proposed date of Borrowing, in the case of an Absolute Rate Auction
(or, in either case, such other time or date as the Company and the Agent shall
have mutually agreed and shall have notified to the Banks not later than the
date of the Money Market Quote Request for the first LIBOR Auction or Absolute
Rate Auction for which such change is to be effective), the Company shall notify
the Agent of its acceptance or non-acceptance of the offers so notified to it
pursuant to subsection (e). In the case of acceptance, such notice (a "Notice of
Money Market Borrowing") shall specify the aggregate principal amount of offers
for each Interest Period that are accepted. The Company may accept any Money
Market Quote in whole or in part; provided that:

               (i) the aggregate principal amount of each Money Market Borrowing
         may not exceed the applicable amount set forth in the related Money
         Market Quote Request;

               (ii) the principal amount of each Money Market Borrowing must be
         $25,000,000 or C$25,000,000, as the case may be, or a larger multiple
         of $5,000,000 or C$5,000,000, as the case may be;

               (iii) acceptance of offers may only be made on the basis of
         ascending Money Market Margins or Money Market Absolute Rates, as the
         case may be; and

               (iv) the Company may not accept any offer that is described in
         subsection (d)(iii) or that otherwise fails to comply with the
         requirements of this Agreement.

         (g) Allocation by Agent. If offers are made by two or more Banks with
the same Money Market Margins or Money Market Absolute Rates, as the case may
be, for a greater aggregate principal amount than the amount in respect of which
such offers are accepted for the related Interest Period, the principal amount
of Money Market Loans in respect of which such offers are accepted shall be
allocated by the Agent among such Banks as nearly as possible (in multiples of
$1,000,000 or C$1,000,000, as the case may be, as the Agent may deem
appropriate) in proportion to the aggregate principal amounts of such offers.
Determinations by the Agent of the amounts of Money Market Loans shall be
conclusive in the absence of manifest error.
<PAGE>   17

         SECTION 2.04. Notice to Banks; Funding of Loans. (a) Promptly upon (and
in any event not later than (w) 12:00 Noon (Toronto time), in the case of a
LIBOR Auction, (x) 11:15 A.M. (Toronto time), in the case of an Absolute Rate
Auction, (y) 11:30 A.M. (Toronto time), in the case of a Base Rate Borrowing,
and (z) 2:30 P.M. (Toronto time), in the case of a Euro-Dollar Borrowing, in
each case on the date of) receipt of a Notice of Borrowing submitted in
accordance with the terms of this Agreement, the Agent shall promptly notify
each Bank of the contents thereof and of such Bank's share (if any) of such
Borrowing and (except as provided in Section 8.01) such Notice of Borrowing
shall not thereafter be revocable by the Company.

         (b) Not later than 12:30 P.M. (Toronto time) on the date of each
Borrowing, each Bank participating therein shall (except as provided in
subsection (c) of this Section) make available its share of such Borrowing, in
funds in U.S. Dollars or Canadian Dollars, as the case may be, immediately
available in Toronto to the Agent at its address referred to in Section 9.01.
Unless the Agent determines that any applicable condition specified in Article 3
has not been satisfied, the Agent will make the funds so received not later than
12:30 P.M. (Toronto time) from the Banks available to the Company at the Agent's
aforesaid address not later than 1:30 P.M. (Toronto time) on the day of receipt.

         (c) If any Bank makes a new Loan hereunder to the Company on a day on
which the Company is to repay all or any part of an outstanding Loan from such
Bank, such Bank shall apply the proceeds of its new Loan to make such repayment
and only an amount equal to the difference (if any) between the amount being
borrowed by the Company and the amount being repaid shall be made available by
such Bank to the Agent as provided in subsection (b) of this Section, or
remitted by the Company to the Agent as provided in Section 2.12, as the case
may be.

         (d) Unless the Agent shall have received notice from a Bank prior to
the date of any Borrowing (or, in the case of a Base Rate Borrowing, prior to
12:00 Noon (Toronto time) on the date of such Borrowing) that such Bank will not
make available to the Agent such Bank's share of such Borrowing, the Agent may
assume that such Bank has made such share available to the Agent on the date of
such Borrowing in accordance with subsections (b) and (c) of this Section and
the Agent may, in reliance upon such assumption, make available to the Company
on such date a corresponding amount. If and to the extent that such Bank shall
not have so made such share available to the Agent, such Bank and the Company
severally agree to repay to the Agent promptly on demand (and in any event
within three Euro-Currency Business Days) such corresponding amount together
with interest thereon, for each day from the date such amount is made available
to the Company until the date such amount is repaid to the Agent, at (i) in the
case of the Company, a rate per annum equal to the interest rate applicable
thereto pursuant to Section 2.07 and (ii) in the case of such Bank, the Base
Rate or the Canadian Prime Rate, as the case may be. If such Bank shall repay to
the Agent such corresponding amount, such amount so repaid shall constitute such
Bank's Loan included in such Borrowing for purposes of this Agreement.

         SECTION 2.05. Notes. (a) The Loans of each Bank to the Company shall be
evidenced by a single Note of the Company payable to the order of such Bank for
the account of its Applicable Lending Office in an amount equal to the aggregate
unpaid principal amount of such Bank's Loans to the Company.

         (b) Each Bank may, by notice to the Company and the Agent, request that
its Loans of a particular type to the Company be evidenced by a separate Note of

<PAGE>   18

the Company in an amount equal to the aggregate unpaid principal amount of such
Loans. Each such Note shall be in substantially the form of Exhibit A hereto
with appropriate modifications to reflect the fact that it evidences solely
Loans of the relevant type. Each reference in this Agreement to the "Note" of
such Bank shall be deemed to refer to and include any or all of such Notes, as
the context may require.

         (c) Upon receipt of each Bank's Note pursuant to Section 3.01(a), the
Agent shall forward such Note to such Bank. Each Bank shall record the date,
currency, amount, type and maturity of each Loan made by it to the Company and
the date and amount of each payment of principal made with respect thereto, and
may, if such Bank so elects in connection with any transfer or enforcement of
its Note, endorse on the schedule forming a part thereof appropriate notations
to evidence the foregoing information with respect to each such Loan to the
Company then outstanding; provided that the failure of any Bank to make any such
recordation or endorsement shall not affect the obligations of the Company
hereunder or under the Notes. Each Bank is hereby irrevocably authorized by the
Company so to endorse its Note and to attach to and make a part of its Note a
continuation of any such schedule as and when required.

         SECTION 2.06. Maturity of Loans. Each Loan included in any Borrowing
made pursuant to Section 2.01(a) shall mature, and the principal amount thereof
shall be due and payable, together with accrued interest thereon, on the
Termination Date. Each Loan included in any Borrowing made pursuant to Section
2.03 shall mature, and the principal amount thereof shall be due and payable, on
the last day of the Interest Period applicable to such Borrowing.

         SECTION 2.07. Interest Rates. (a) Each Base Rate Loan shall bear
interest on the outstanding principal amount thereof, for each day from the date
such Loan is made until it becomes due, at a rate per annum equal to the Base
Rate for such day. Such interest shall be payable quarterly in arrears on the
last day of each quarter and, with respect to the principal amount of any Base
Rate Loan converted to a Euro-Dollar Loan, on the date of such conversion. Any
overdue principal of or interest on any Base Rate Loan shall bear interest,
payable on demand, for each day until paid at a rate per annum equal to the sum
of 2% plus the rate otherwise applicable to Base Rate Loans for such day.

         (b) Each Euro-Dollar Loan shall bear interest on the outstanding
principal amount thereof, for each day during the Interest Period applicable
thereto, at a rate per annum equal to the sum of the Euro-Dollar Margin for such
day plus the London Interbank Offered Rate applicable to such Interest Period.
Such interest shall be payable for each Interest Period on the last day thereof
and, if such Interest Period is longer than three months, at intervals of three
months after the first day thereof.

         The "London Interbank Offered Rate" applicable to any Interest Period
means the rate appearing on Page 3750 (in the case of Loans denominated in U.S.
Dollars) or Page 3745 (in the case of Loans denominated in Canadian Dollars) of
the Dow Jones Market Service (or on any successor or substitute page of such
Service, or any successor to or substitute for such Service, providing rate
quotations comparable to those currently provided on such page of such Service,
as determined by the Agent from time to time for purposes of providing
quotations of interest rates applicable to deposits in the currency in which
such Loan is denominated in the London interbank market) at approximately 11:00
A.M. (London time) two Euro-Currency Business Days prior to commencement of such
Interest Period, as the rate for deposits in the currency in which such Loan is
denominated with a maturity comparable to such Interest Period. In the event

<PAGE>   19

that such rate is not available at such time for any reason, the "London
Interbank Offered Rate" applicable to such Interest Period shall be the average
(rounded upward, if necessary, to the next higher 1/16 of 1%) of the respective
rates per annum at which deposits in the currency in which such Loan is
denominated are offered to each of the Reference Banks by leading banks in the
London interbank market at approximately 11:00 A.M. (London time) two
Euro-Currency Business Days before the first day of such Interest Period in an
amount approximately equal to the principal amount of the Loan of such Reference
Bank to which such Interest Period is to apply and for a period of time
comparable to such Interest Period.

          (c) Any overdue principal of or interest on any Euro-Dollar Loan shall
bear interest, payable on demand, for each day until paid at a rate per annum
equal to the sum of 2% plus the Euro-Dollar Margin for such day plus the higher
of (i) the London Interbank Offered Rate applicable to the Interest Period for
such Loan and (ii) the average (rounded upward, if necessary, to the next higher
1/16 of 1%) of the respective rates per annum at which one day (or, if such
amount due remains unpaid more than three Euro-Currency Business Days, then for
such other period of time not longer than three months as the Agent may select)
deposits in U.S. Dollars in an amount approximately equal to such overdue
payment due to each of the Reference Banks are offered to such Reference Bank by
leading banks in the London interbank market for the applicable period
determined as provided above (or, if the circumstances described in clause (a)
or (b) of Section 8.01 shall exist, at a rate per annum equal to the sum of 2%
plus the rate applicable to Base Rate Loans for such day).

         (d) Subject to Section 8.01, each Money Market LIBOR Loan shall bear
interest on the outstanding principal amount thereof, for the Interest Period
applicable thereto, at a rate per annum equal to the sum of the London Interbank
Offered Rate for such Interest Period (determined in accordance with Section
2.07(b) as if the related Money Market LIBOR Borrowing were a Committed
Euro-Dollar Borrowing or a Committed Borrowing in Canadian Dollars, as the case
may be) plus (or minus) the Money Market Margin quoted by the Bank making such
Loan in accordance with Section 2.03. Each Money Market Absolute Rate Loan shall
bear interest on the outstanding principal amount thereof, for the Interest
Period applicable thereto, at a rate per annum equal to the Money Market
Absolute Rate quoted by the Bank making such Loan in accordance with Section
2.03. Such interest shall be payable for each Interest Period on the last day
thereof and, if such Interest Period is longer than three months, at intervals
of three months after the first day thereof. Any overdue principal of or
interest on any Money Market Loan shall bear interest, payable on demand, for
each day until paid at a rate per annum equal to the sum of 2% plus (i) if such
Money Market Loan is denominated in U.S. Dollars, the Base Rate for such day and
(ii) if such Money Market Loan is denominated in Canadian Dollars, the Canadian
Prime Rate for such day.

         (e) The Agent shall determine each interest rate applicable to the
Loans hereunder. The Agent shall give prompt notice to the Company and the
participating Banks of each rate of interest so determined, and its
determination thereof shall be conclusive in the absence of manifest error.

         (f) Each Reference Bank agrees to use its best efforts to furnish
quotations to the Agent as contemplated by this Section. If any Reference Bank
does not furnish a timely quotation, the Agent shall determine the relevant
interest rate on the basis of the quotation or quotations furnished by the
remaining Reference Bank or Banks or, if none of such quotations is available on
a timely basis, the provisions of Section 8.01 shall apply.
<PAGE>   20

         SECTION 2.08. Fees. (a) The Company shall pay to the Agent for the
account of the Banks ratably a facility fee at the Facility Fee Rate (determined
daily in accordance with, and as defined in, the Pricing Schedule). Such
facility fee shall accrue (i) from and including the Closing Date to but
excluding the date of termination of the Commitments in their entirety, on the
daily aggregate amount of the Commitments (whether used or unused) and (ii) from
and including such date of termination to but excluding the date the Loans shall
be repaid in their entirety, on the daily aggregate outstanding principal amount
of the Loans.

         (b) Accrued fees under this Section shall be payable quarterly in
arrears on each March 31, June 30, September 30, December 31 and on the date of
termination of the Commitments of each Bank in its entirety (and, if later, the
date the Loans of such Bank shall be repaid in their entirety).

         SECTION 2.09. Optional Termination or Reduction of Commitments. During
the Revolving Credit Period, the Company may, upon at least three Domestic
Business Days' notice to the Agent, (i) terminate the Commitments at any time,
if no Loans are outstanding at such time or (ii) ratably reduce from time to
time by an aggregate amount of $25,000,000 or a larger multiple of $5,000,000,
the aggregate amount of the Commitments in excess of the aggregate outstanding
principal amount of the Loans.

         SECTION 2.10. Method of Electing Interest Rates. (a) The Loans included
in each Committed Borrowing shall bear interest initially at the type of rate
specified by the Company in the applicable Notice of Committed Borrowing.
Thereafter, the Company may from time to time elect to change or continue the
type of interest rate borne by each Group of Loans (subject in each case to the
provisions of Article 8) , as follows: (i) if such Loans are Base Rate Loans,
the Company may elect to convert such Loans to Euro-Dollar Loans as of any Euro-
Currency Business Day, or (ii) if such Loans are Euro-Dollar Loans, the Company
may elect to convert such Loans to Base Rate Loans or elect to continue such
Loans as Euro-Dollar Loans for an additional Interest Period, in each case
effective on the last day of the then current Interest Period applicable to such
Loans. Each such election shall be made by delivering a notice (a "Notice of
Interest Rate Election") to the Agent at least three Euro-Currency Business Days
before the conversion or continuation selected in such notice is to be
effective. A Notice of Interest Rate Election may, if it so specifies, apply to
only a portion of the aggregate principal amount of the relevant Group of Loans;
provided that (i) such portion is allocated ratably among the Loans comprising
such Group and (ii) the portion to which such Notice applies, and the remaining
portion to which it does not apply, are each $25,000,000 or C$25,000,000 or any
larger multiple of $5,000,000 or C$5,000,000, as the case may be.

         (b) Each Notice of Interest Rate Election shall specify: (i) the Group
of Loans (or portion thereof) to which such notice applies; (ii) the date on
which the conversion or continuation selected in such notice is to be effective,
which shall comply with the applicable clause of subsection (a) above; (iii) if
the Loans comprising such Group are to be converted, the new type of Loans and,
if such new Loans are Euro-Dollar Loans, the duration of the initial Interest
Period applicable thereto; and (iv) if such Loans are to be continued as
Euro-Dollar Loans for an additional Interest Period, the duration of such
additional Interest Period. Each Interest Period specified in a Notice of
Interest Rate Election shall comply with the provisions of the definition of
Interest Period.
<PAGE>   21

         (c) Upon receipt of a Notice of Interest Rate Election from the Company
pursuant to subsection (a) above, the Agent shall promptly notify each Bank of
the contents thereof and such notice shall not thereafter be revocable by the
Company. If the Company fails to deliver a timely Notice of Interest Rate
Election to the Agent for any Group of Euro-Dollar Loans, such Loans shall be
converted into Base Rate Loans on the last day of the then current Interest
Period applicable thereto.

         SECTION 2.11. Optional Prepayments. (a) Subject in the case of any
Euro-Dollar Borrowing to Section 2.13, the Company may, upon at least one
Domestic Business Day's notice to the Agent, prepay the Group of Base Rate Loans
(or any Money Market Borrowing bearing interest at the Base Rate or the Canadian
Prime Rate, as the case may be, pursuant to Section 8.01) or upon at least three
Euro-Currency Business Days' notice to the Agent, prepay any Group of
Euro-Dollar Loans, in each case in whole at any time, or from time to time in
part in amounts aggregating $5,000,000 or C$5,000,000 or any larger multiple of
$5,000,000 or C$5,000,000, as the case may be, by paying the principal amount to
be prepaid together with accrued interest thereon to the date of prepayment.
Each such optional prepayment shall be applied to prepay ratably the Loans of
the several Banks included in such Borrowing.

         (b) Except as provided in subsection (a) above or Section 8.02, the
Company may not prepay all or any portion of the principal amount of any Money
Market Loan prior to the maturity thereof.

         (c) Upon receipt of a notice of prepayment pursuant to this Section,
the Agent shall promptly notify each Bank of the contents thereof and of such
Bank's ratable share (if any) of such prepayment and such notice shall not
thereafter be revocable by the Company.

         SECTION 2.12. General Provisions as to Payments. (a) Each Borrowing
shall be repaid or prepaid in the currency in which it was made in the amount
borrowed and interest payable thereon shall be paid in such currency.

         (b) The Company shall make each payment of principal of, and interest
on, the Loans and of fees hereunder, not later than 12:00 Noon (Toronto time) on
the date when due, in funds immediately available in Toronto, to the Agent at
its address referred to in Section 9.01. The Agent will promptly distribute to
each Bank its ratable share of each such payment received by the Agent for the
account of the Banks. Whenever any payment of principal of, or interest on, the
Base Rate Loans or of fees shall be due on a day which is not a Domestic
Business Day, the date for payment thereof shall be extended to the next
succeeding Domestic Business Day. Whenever any payment of principal of, or
interest on, the Euro-Dollar Loans shall be due on a day which is not a
Euro-Currency Business Day, the date for payment thereof shall be extended to
the next succeeding Euro-Currency Business Day unless such Euro-Currency
Business Day falls in another calendar month, in which case the date for payment
thereof shall be the next preceding Euro-Currency Business Day. Whenever any
payment of principal of, or interest on, the Money Market Loans shall be due on
a day which is not a Euro-Currency Business Day, the date for payment thereof
shall be extended to the next succeeding Euro-Currency Business Day. If the date
for any payment of principal is extended by operation of law or otherwise,
interest thereon shall be payable for such extended time.

         (c) Unless the Agent shall have received notice from the Company prior
to the date on which any payment is due from the Company to the Banks hereunder
that the Company will not make such payment in full, the Agent may assume that

<PAGE>   22

the Company has made such payment in full to the Agent on such date and the
Agent may, in reliance upon such assumption, cause to be distributed to each
Bank on such due date an amount equal to the amount then due such Bank. If and
to the extent that the Company shall not have so made such payment, each Bank
shall repay to the Agent forthwith on demand such amount distributed to such
Bank together with interest thereon, for each day from the date such amount is
distributed to such Bank until the date such Bank repays such amount to the
Agent, at the Base Rate or the Canadian Prime Rate, as the case may be.

         SECTION 2.13. Funding Losses. If the Company makes any payment of
principal with respect to any Fixed Rate Loan (pursuant to Article 2, 6 or 8
(other than Section 8.02) or otherwise) on any day other than the last day of
the Interest Period applicable thereto, or the last day of an applicable period
fixed pursuant to Section 2.07(c), or if the Company fails to borrow or prepay
any Fixed Rate Loans after notice has been given to any Bank in accordance with
Section 2.04(a) or 2.11(a) (except as a result of (x) a default by the Agent or
any Bank in observing the terms of this Agreement or (y) an election not to
borrow pursuant to Section 8.01), the Company shall reimburse each Bank within
15 days after demand for any resulting loss or expense directly incurred by it,
including (without limitation) any loss incurred in obtaining, liquidating or
employing deposits from third parties, but excluding consequential damages and
loss of margin for the period after any such payment or failure to borrow or
prepay, provided that such Bank (x) shall have delivered to the Company a
certificate as to the amount of such loss or expense, and (y) shall use all
reasonable efforts to mitigate the amount payable by the Company under this
Section 2.13.

         SECTION 2.14. Computation of Interest and Fees. Interest based on the
Canadian Prime Rate hereunder shall be computed on the basis of a year of 365
days (or 366 days in a leap year) and paid for the actual number of days elapsed
(including the first day but excluding the last day). All other interest and
fees shall be computed on the basis of a year of 360 days and paid for the
actual number of days elapsed (including the first day but excluding the last
day).

         SECTION 2.15. Interest Act Equivalency. For purposes of disclosure
pursuant to the Interest Act (Canada), the yearly rate of interest to which any
rate of interest other than the Canadian Prime Rate is equivalent, may be
determined by multiplying the applicable rate by a fraction, the numerator of
which is the number of days in the calendar year in which the period for which
such interest payable occurs and the denominator of which is 360.

         SECTION 2.16. Judgment Currency. If for the purpose of obtaining
judgment in any court it is necessary to convert a sum due from the Company
hereunder or under any of the Notes in the currency expressed to be payable
herein or under the Notes (the "specified currency") into another currency, the
parties hereto agree, to the fullest extent that they may effectively do so,
that the rate of exchange used shall be that at which in accordance with normal
banking procedures the Agent could purchase the specified currency with such
other currency at the Agent's Toronto office on the Domestic Business Day
preceding that on which final judgment is given. The obligations of the Company
in respect of any sum due to any Bank or the Agent hereunder or under any Note
shall, notwithstanding any judgment in a currency other than the specified
currency, be discharged only to the extent that on the Domestic Business Day
following receipt by such Bank or the Agent (as the case may be) of any sum
adjudged to be so due in such other currency such Bank or the Agent (as the case
may be) may in accordance with normal banking procedures purchase the specified

<PAGE>   23

currency with such other currency; if the amount of the specified currency so
purchased is less than the sum originally due to such Bank or the Agent, as the
case may be, in the specified currency, the Company agrees, to the fullest
extent that it may effectively do so, as a separate obligation and
notwithstanding any such judgment, to indemnify such Bank or the Agent, as the
case may be, against such loss, and if the amount of the specified currency so
purchased exceeds (a) the sum originally due to any Bank or the Agent, as the
case may be, in the specified currency and (b) any amounts shared with other
Banks as a result of allocations of such excess as a disproportionate payment to
such Bank under Section 9.04, such Bank or the Agent, as the case may be, agrees
to remit such excess to the Company.


                                    ARTICLE 3
                                   CONDITIONS

         SECTION 3.01.  Closing.  The closing hereunder shall occur upon receipt
by the Agent of the following documents, each dated the Closing Date unless
otherwise indicated:

          (a) a duly executed Note of the Company for the account of each Bank
dated on or before the Closing Date complying with the provisions of Section
2.05;

          (b) an opinion of Nicholas J. DeRoma, Chief Legal Officer of the
Company, substantially in the form of Exhibit E hereto;

          (c) an opinion of Davis Polk & Wardwell, special counsel for the
Agent, substantially in the form of Exhibit F hereto;

          (d) a certificate, signed by the Chief Financial Officer or the
Controller of the Company, in form and substance satisfactory to the Agent
stating that since December 31, 1999 there has been no material adverse change
in the business, financial position, results of operations or prospects of the
Company and its Consolidated Subsidiaries, considered as a whole; and

          (e) all documents the Agent may reasonably request relating to the
existence of the Company, the corporate authority for and the validity of this
Agreement and the Notes, and any other matters relevant hereto, all in form and
substance satisfactory to the Agent.

The Agent shall promptly notify the Company and the Banks of the Closing Date,
and such notice shall be conclusive and binding on all parties hereto.

         SECTION 3.02.  Borrowings.  The obligation of any Bank to make a Loan
on the occasion of any Borrowing is subject to the satisfaction of the following
conditions:

          (a) the fact that the Closing Date shall have occurred on or prior to
April 12, 2000;

          (b) receipt by the Agent of a Notice of Borrowing as required by
Section 2.02 or 2.03, as the case may be;

          (c) the fact that, immediately after such Borrowing, the aggregate
outstanding principal amount of the Committed Loans will not exceed the
aggregate amount of the Commitments;
<PAGE>   24

          (d) the fact that, immediately before and after such Borrowing, no
Default shall have occurred and be continuing;

          (e) the fact that the representations and warranties of the Company
contained in this Agreement shall be true on and as of the date of such
Borrowing; and

          (f) in the case of any Borrowing which would violate any limitation
imposed by the board of directors of the Company in effect on the date hereof on
the principal amount of any financing or the outstanding principal amount of any
financings of the Company, receipt by the Agent of a copy, certified by an
appropriate officer of the Company, of the resolutions of the board of directors
of the Company pursuant to which such Borrowing is authorized.

Each Borrowing hereunder shall be deemed to be a representation and warranty by
the Company on the date of such Borrowing as to the facts specified in clauses
(c), (d) and (e) of this Section.


                                    ARTICLE 4
                         REPRESENTATIONS AND WARRANTIES

         The Company represents and warrants that:

         SECTION 4.01. Corporate Existence and Power. The Company is a
corporation duly incorporated and validly existing under the laws of the
jurisdiction of its incorporation, and has all corporate powers and all
governmental licenses, authorizations, consents and approvals required to carry
on its business as now conducted, the absence of which would have a material
adverse effect on the ability of the Company to perform its obligations under
this Agreement.

         SECTION 4.02. Corporate and Governmental Authorization; No
Contravention. The execution, delivery and performance by the Company of this
Agreement and its Notes (i) are within the Company's corporate powers and have
been duly authorized by all necessary corporate action, (ii) require no action
by or in respect of, or filing with, any governmental body, agency or official
and (iii) do not contravene any provision of applicable law or regulation or any
provision of the certificate of incorporation or by-laws of the Company or any
contractual restriction, order, decree or other instrument binding upon the
Company or any of its Subsidiaries, except, in the case of clauses (ii) and
(iii) above, any such action, filing or contravention which would not have a
material adverse effect on the ability of the Company to perform its obligations
under this Agreement.

         SECTION 4.03. Binding Effect. This Agreement constitutes a valid and
binding agreement of the Company and each Note, when executed and delivered in
accordance with this Agreement, will constitute a valid and binding obligation
of the Company, in each case enforceable in accordance with its terms, except as
the same may be limited by bankruptcy, insolvency or similar laws affecting
creditors' rights generally, by general principles of equity (it being
understood that the enforceability thereof in Canada may be limited by the
Currency Act (Canada), which precludes Canadian courts from awarding a judgment
for an amount expressed in a currency other than Canadian Dollars and to the
extent that any requirement to pay interest at a greater rate after than before
default may not be enforceable in Canada if the same is construed by a Canadian

<PAGE>   25

court to constitute a penalty).

         SECTION 4.04. Financial Information. The consolidated balance sheet of
the Company and its Consolidated Subsidiaries as of December 31, 1999 and the
related consolidated statements of operations, cash flows and retained earnings
for the fiscal year then ended, reported on by Deloitte & Touche LLP and set
forth in the Company's 1999 Form 10-K, fairly present, in conformity with
Canadian generally accepted accounting principles, the consolidated financial
position of the Company and its Consolidated Subsidiaries as of such date and
their consolidated results of operations and cash flows for such fiscal year.

         SECTION 4.05. Litigation. There is no action, suit or proceeding
pending against, or to the knowledge of the Company threatened against or
affecting, the Company or any of its Subsidiaries before any court or arbitrator
or any governmental body, agency or official in which there is a reasonable
possibility of an adverse decision which could have a material adverse effect on
the ability of the Company to perform its obligations under this Agreement, or
which in any manner draws into question the validity of this Agreement or the
Notes.


                                    ARTICLE 5
                                    COVENANTS

         The Company agrees that, so long as any Bank has any Commitment
hereunder or any amount payable under any Note remains unpaid:

         SECTION 5.01. Information. The Company will deliver to each of the
Banks:

          (a) as soon as available and in any event within 120 days after the
end of each fiscal year of the Company, the Company's annual report on Form 10-K
as filed with the Securities and Exchange Commission, including a consolidated
balance sheet of the Company and its Consolidated Subsidiaries as of the end of
such fiscal year and the related consolidated statements of operations, cash
flows and retained earnings for such fiscal year, setting forth in each case in
comparative form the figures for the previous fiscal year, all reported on in a
manner acceptable to the Securities and Exchange Commission by Deloitte & Touche
LLP or other independent public accountants of nationally recognized standing;

          (b) as soon as available and in any event within 60 days after the end
of each of the first three quarters of each fiscal year of the Company, the
Company's quarterly report on Form 10-Q as filed with the Securities and
Exchange Commission, including a consolidated balance sheet of the Company and
its Consolidated Subsidiaries as of the end of such quarter and the related
consolidated statements of operations, cash flows and retained earnings for such
quarter and for the portion of the Company's fiscal year ended at the end of
such quarter, setting forth in the case of such statements of operations, cash
flows and retained earnings, in comparative form the figures for the
corresponding quarter and the corresponding portion of the Company's previous
fiscal year;

          (c) simultaneously with the delivery of each set of financial
statements referred to in clauses (a) and (b) above, a copy of a certificate of
the Treasurer of the Company (with the original of such certificate delivered to
the Agent) stating whether to the best of such Person's knowledge, after having
conducted a reasonable investigation, any Default exists on the date of such

<PAGE>   26

certificate and, if any Default then exists, setting forth reasonable details
thereof;

          (d) within five days after any Executive Officer of the Company
obtains knowledge of any Default, if such Default is then continuing, notice of
such Default;

          (e)   promptly after the mailing thereof to the shareholders of the
Company generally, copies of all other reports and proxy statements so mailed;

          (f) promptly after the filing thereof, copies of all registration
statements (other than the exhibits thereto and any registration statements on
Form S-8 or its equivalent) and reports on Form 8-K (or its equivalent) which
the Company shall have filed with the Securities and Exchange Commission; and

          (g) from time to time such additional information regarding the
financial position or business of the Company and its Subsidiaries as any Bank
may reasonably request through the Agent as being desirable to enable such Bank
to protect its rights under this Agreement; provided that the Company shall not
be under any obligation to supply any information the supply of which would be
contrary to any confidentiality obligation binding on the Company or any of its
Subsidiaries or which, in the Company's opinion, is unpublished price sensitive
information or the supply of which would, in the Company's opinion, be contrary
to any applicable securities laws or the regulations of any relevant stock
exchange.

         SECTION 5.02. Conduct of Business and Maintenance of Existence; Merger
and Sales of Assets. (a) The Company will continue, and will cause each Material
Subsidiary to continue, to engage in business of the same general type as now
conducted by the Company and its Material Subsidiaries, and will preserve, renew
and keep in full force and effect, and will cause each Material Subsidiary to
preserve, renew and keep in full force and effect, their respective corporate
existence and their respective rights, privileges and franchises necessary or
desirable in the normal conduct of business; provided that nothing in this
subsection (a) shall prohibit (i) the amalgamation, merger or consolidation of a
Material Subsidiary with or into the Company or the amalgamation, merger or
consolidation of a Material Subsidiary with or into another Person if the
corporation surviving such amalgamation, merger or consolidation is a Material
Subsidiary and if, in each case, after giving effect thereto, no Default shall
have occurred and be continuing or (ii) the termination of the corporate
existence of any Material Subsidiary, or any change in, or termination of, the
business of any Material Subsidiary, or any disposition of the Company's
interest in any Material Subsidiary in whole or in part (including by way of
amalgamation, merger or consolidation), if the Company in good faith determines
that such termination, change or disposition is in the best interest of the
Company and would not materially and adversely affect the ability of the Company
to perform its obligations under this Agreement.

          (b) The Company will not (i) amalgamate, consolidate or merge with or
into any other Person or (ii) sell, lease or otherwise transfer, directly or
indirectly, all or substantially all of the assets of the Company and its
Subsidiaries, taken as a whole, to any other Person, unless:

                  (x) the corporation formed by such amalgamation or
         consolidation or into which the Company is merged (in each case, if
         other than the Company) or the Person that acquires substantially all
         of the assets of the Company is a corporation organized under the laws

<PAGE>   27

         of Canada or the United States that expressly assumes, by an
         unconditional written instrument executed and delivered to the Agent
         and the Banks, the due and punctual performance of all of the Company's
         obligations hereunder; and

                  (y) after giving effect to such amalgamation, consolidation,
         merger, sale, lease or other transfer and to the assumption referred to
         in clause (x) above, if applicable, no Default has occurred and is
         continuing.

         SECTION 5.03. Use of Proceeds. The proceeds of the Loans made under
this Agreement will be used by the Company for general corporate purposes. None
of such proceeds will be used, directly or indirectly, for the purpose, whether
immediate, incidental or ultimate, of buying or carrying any "margin stock"
within the meaning of Regulation U.

         SECTION 5.04. Negative Pledge. (a) Subject to the following exceptions,
the Company will not, and will not permit NNI, to issue, assume or guarantee any
Funded Debt secured by, and will not secure any Funded Debt by, a Mortgage upon
any property of the Company or NNI (whether now owned or hereafter acquired)
without in any such case effectively providing concurrently therewith that the
Loans shall be secured equally and ratably with such Funded Debt; provided,
however, that the foregoing restrictions shall not apply to Funded Debt secured
by:

               (i) Purchase Money Mortgages;

               (ii) Mortgages on property of a corporation existing at the time
          such corporation is liquidated or merged into, or amalgamated or
          consolidated with, the Company or NNI or at the time of a sale, lease
          or other disposition to the Company or NNI of the properties of a
          corporation as, or substantially as, an entirety;

               (iii) Mortgages to secure indebtedness of NNI to the Company or
          to secure indebtedness of the Company to NNI;

               (iv) Mortgages in favor of the United States, Canada or any
          Province thereof, or any department, agency or instrumentality or
          political subdivision thereof, or in favor of any other country or
          political subdivision, to secure partial, progress, advance or other
          payments pursuant to any contract or statute or to secure any
          indebtedness incurred or guaranteed for the purpose of financing or
          refinancing all or any part of the purchase price of the property,
          shares of capital stock or indebtedness subject to such Mortgages, or
          the cost of constructing or improving the property subject to such
          Mortgages (including, without limitation, Mortgages incurred in
          connection with pollution control, industrial revenue or similar
          financings); and

               (v) any extension, renewal or replacement (or successive
          extensions, renewals or replacements) in whole or in part of any
          Mortgage existing at the Effective Date or any Mortgage referred to in
          the foregoing clauses (i) through (iv), inclusive, provided, however,
          that the principal amount of the Funded Debt secured thereby shall not
          exceed the principal amount of the Funded Debt so secured at the time
          of such extension, renewal or replacement, and that such extension,
          renewal or replacement shall be limited to all or part of the property

<PAGE>   28

          (plus improvements and construction on such property) or indebtedness
          that was subject to the Mortgage so extended, renewed or replaced.

          (b) Notwithstanding the foregoing, the Company or NNI may issue,
assume or guarantee Funded Debt secured by a Mortgage upon any property of the
Company or NNI that would otherwise be subject to the foregoing restrictions,
and may carry out any other transactions which would otherwise be subject to the
foregoing restrictions, provided the aggregate amount of all (1) such Funded
Debt and (2) Attributable Debt in respect of all Financing Leases entered into
on or after the Effective Date would not, after giving effect thereto, exceed
15% of the Company's Consolidated Net Tangible Assets.

          (c) The Company will not, and will not permit NNI to, enter into any
Financing Leases covering any property of NNI or the Company unless: (1)
immediately thereafter the sum of (i) the Attributable Debt in respect of all
Financing Leases entered into on or after the Effective Date and (ii) the
aggregate amount of all Funded Debt secured by a Mortgage (exclusive of any
secured Funded Debt permitted by clauses (i) through (v) of subsection (a) of
this Section 5.04) does not exceed 15% of the Company's Consolidated Net
Tangible Assets; (2) the Company or NNI would (at the time of entering into such
arrangement) be entitled, pursuant to clauses (i) to (v) of subsection (a) of
this Section 5.04, without equally and ratably securing the Loans, to issue,
assume or guarantee indebtedness secured by a Mortgage on such property; or (3)
the Company or NNI shall apply, within 360 days of the effective date of any
such arrangement, an amount equal to the Attributable Debt in respect of such
Financing Leases to the prepayment or retirement of indebtedness incurred or
assumed by the Company or NNI (other than indebtedness owned by the Company or
NNI) which by its terms matures at or is extendible or renewable at the option
of the obligor to a date more than 12 months after the date of the creation of
such indebtedness.

         SECTION 5.05.  Minimum Consolidated Tangible Net Worth.  Consolidated
Tangible Net Worth will at no time be less than $1,888,000,000.


                                    ARTICLE 6
                                    DEFAULTS

         SECTION 6.01. Events of Default. If one or more of the following
events ("Events of Default") shall have occurred and be continuing:

          (a) the Company shall fail to pay when due any principal of any Loan
or shall fail to pay any interest, any fees or any other amount payable
hereunder within five days of the due date thereof;

          (b) the Company shall fail to observe or perform any covenant
contained in Sections 5.02(b), 5.04 or 5.05;

          (c) the Company shall fail to observe or perform any covenant or
agreement contained in this Agreement (other than those covered by clause (a) or
(b) above) and does not remedy the failure on or before thirty days after notice
thereof has been given to the Company by the Agent at the request of any Bank;

          (d) any representation or warranty made (or, pursuant to Section 3.02,
deemed made) by the Company in this Agreement or in any certificate delivered
pursuant to this Agreement shall prove to have been incorrect in any material
respect when made (or deemed made);
<PAGE>   29

          (e) an event of default as defined in any evidence of indebtedness for
borrowed money of the Company exceeding on its face $100,000,000 in principal
amount (whether such indebtedness now exists or shall hereafter be created)
shall have occurred, which results in such indebtedness becoming or being
declared due and payable prior to the date on which it would otherwise become
due and payable and such acceleration shall not be rescinded or annulled within
10 days of written notice of such acceleration; or

          (f) the Company or any Material Subsidiary shall commence a voluntary
case or other proceeding seeking liquidation, reorganization or other relief
with respect to itself or its debts under any bankruptcy, insolvency or other
similar law now or hereafter in effect or seeking the appointment of a trustee,
receiver, liquidator, custodian or other similar official of it or any
substantial part of its property, or shall consent to any such relief or to the
appointment of or taking possession by any such official in an involuntary case
or other proceeding commenced against it, or shall make a general assignment for
the benefit of creditors, or shall fail generally to pay its debts as they
become due, or shall take any corporate action to authorize any of the
foregoing;

          (g) an involuntary case or other proceeding shall be commenced against
the Company or any Material Subsidiary seeking liquidation, reorganization or
other relief with respect to it or its debts under any bankruptcy, insolvency or
other similar law now or hereafter in effect or seeking the appointment of a
trustee, receiver, liquidator, custodian or other similar official of it or any
substantial part of its property, and such involuntary case or other proceeding
shall remain undismissed and unstayed for a period of 60 days; or an order for
relief shall be entered against the Company or any Material Subsidiary under the
bankruptcy or insolvency laws as now or hereafter in effect in Canada or the
United States;

          (h) judgments or orders for the payment of money in excess of
$300,000,000 shall be rendered against the Company or any Subsidiary and such
judgments or orders shall continue unsatisfied and unstayed for a period of 30
days, if, after such 30-day period, such continuation has a material adverse
impact on the ability of the Company to perform its obligations under this
Agreement; or

          (i) a Change of Control shall occur;

then, and in every such event, the Agent shall (i) if requested by Banks having
more than 50% in aggregate amount of the Commitments, by notice to the Company
terminate the Commitments and they shall thereupon terminate, and (ii) if
requested by Banks holding more than 50% of the aggregate principal amount of
the Loans, by notice to the Company declare the Loans (together with accrued
interest thereon) to be, and the Loans shall thereupon become, immediately due
and payable without presentment, demand, protest or other notice of any kind,
all of which are hereby waived by the Company; provided that in the case of any
of the Events of Default specified in clause 6.01(f) or 6.01(g) above with
respect to the Company, without any notice to the Company or any other act by
the Agent or the Banks, the Commitments shall thereupon terminate and the Loans
(together with accrued interest thereon) shall become immediately due and
payable without presentment, demand, protest or other notice of any kind, all of
which are hereby waived by the Company.

         SECTION 6.02. Notice of Default. The Agent shall give notice to the

<PAGE>   30

Company under Section 6.01(c) promptly upon being requested to do so by any Bank
and shall thereupon notify all the Banks thereof.


                                    ARTICLE 7
                    THE AGENT [AND THE CO-SYNDICATION AGENTS]

         SECTION 7.01. Appointment and Authorization. Each Bank irrevocably
appoints and authorizes the Agent to take such action as agent on its behalf and
to exercise such powers under this Agreement and the Notes as are delegated to
the Agent by the terms hereof or thereof, together with all such powers as are
reasonably incidental thereto.

         SECTION 7.02. Agent and Affiliates. J.P. Morgan Canada shall have the
same rights and powers under this Agreement as any other Bank and may exercise
or refrain from exercising the same as though it were not the Agent, and J.P.
Morgan Canada and its affiliates may accept deposits from, lend money to, and
generally engage in any kind of business with the Company or any Subsidiary or
Affiliate of the Company as if it were not the Agent.

         SECTION 7.03. Action by Agent. The obligations of the Agent hereunder
are only those expressly set forth herein. Without limiting the generality of
the foregoing, the Agent shall not be required to take any action with respect
to any Default, except as expressly provided in Article 6.

         SECTION 7.04. Consultation with Experts. The Agent may consult with
legal counsel (who may be counsel for the Company), independent public
accountants and other experts selected by it and shall not be liable for any
action taken or omitted to be taken by it in good faith in accordance with the
advice of such counsel, accountants or experts.

         SECTION 7.05. Liability of Agent. Neither the Agent nor any of its
affiliates nor any of their respective directors, officers, agents or employees
shall be liable for any action taken or not taken by it in connection herewith
(i) with the consent or at the request of the Required Banks or (ii) in the
absence of its own gross negligence or willful misconduct. Neither the Agent nor
any of its affiliates nor any of their respective directors, officers, agents or
employees shall be responsible for or have any duty to ascertain, inquire into
or verify (i) any statement, warranty or representation made in connection with
this Agreement or any borrowing hereunder; (ii) the performance or observance of
any of the covenants or agreements of the Company; (iii) the satisfaction of any
condition specified in Article 3, except receipt of items required to be
delivered to the Agent; or (iv) the validity, effectiveness or genuineness of
this Agreement, the Notes or any other instrument or writing furnished in
connection herewith. The Agent shall not incur any liability by acting in
reliance upon any notice, consent, certificate, statement, or other writing
(which may be a bank wire, telex, facsimile transmission or similar writing)
believed by it to be genuine or to be signed by the proper party or parties.

         SECTION 7.06. Indemnification. Each Bank shall, ratably in accordance
with its Commitment, indemnify the Agent, its affiliates and their respective
directors, officers, agents and employees (to the extent not reimbursed by the
Company) against any cost, expense (including counsel fees and disbursements),
claim, demand, action, loss or liability (except such as result from such
indemnitees' gross negligence or willful misconduct) that such indemnitees may
suffer or incur in connection with this Agreement or any action taken or omitted
by such indemnitees hereunder.
<PAGE>   31

         SECTION 7.07. Credit Decision. Each Bank acknowledges that it has,
independently and without reliance upon the Agent or any other Bank, and based
on such documents and information as it has deemed appropriate, made its own
credit analysis and decision to enter into this Agreement. Each Bank also
acknowledges that it will, independently and without reliance upon the Agent or
any other Bank, and based on such documents and information as it shall deem
appropriate at the time, continue to make its own credit decisions in taking or
not taking any action under this Agreement.

         SECTION 7.08. Successor Agent. The Agent may resign at any time by
giving notice thereof to the Banks and the Company. Upon any such resignation,
the Required Banks (80%) shall have the right to appoint a successor Agent
reasonably acceptable to the Company. If no successor Agent shall have been so
appointed by the Required Banks (80%), and shall have accepted such appointment,
within 30 days after the retiring Agent gives notice of resignation, then the
retiring Agent may, on behalf of the Banks, appoint a successor Agent reasonably
acceptable to the Company, which shall be a Canadian chartered bank having a
combined capital and surplus of at least $200,000,000. Upon the acceptance of
its appointment as Agent hereunder by a successor Agent, such successor Agent
shall thereupon succeed to and become vested with all the rights and duties of
the retiring Agent, and the retiring Agent shall be discharged from its duties
and obligations hereunder. After any retiring Agent's resignation hereunder as
Agent, the provisions of this Article shall inure to its benefit as to any
actions taken or omitted to be taken by it while it was Agent.

         SECTION 7.09.  Agent's Fee.  The Company shall pay to the Agent for its
own account fees in the amounts and at the times previously agreed upon in
writing between the Company and the Agent.

         SECTION 7.10. Co-Syndication Agents. The Co-Syndication Agents shall
have no responsibility or obligation under this Agreement in their capacity as
Co-Syndication Agents.



                                    ARTICLE 8
                             CHANGE IN CIRCUMSTANCES

         SECTION 8.01. Basis for Determining Interest Rate Inadequate or
Unfair. If on or prior to the first day of any Interest Period for any
Euro-Dollar Loan or Money Market LIBOR Loan:

          (a) the Agent is advised by the Reference Banks that deposits in the
applicable currency (in the applicable amounts) are not being offered to the
Reference Banks in the London interbank market for such Interest Period, or

          (b) in the case of a Committed Borrowing, Banks having 50% or more of
the aggregate amount of the Commitments advise the Agent that the London
Interbank Offered Rate as determined by the Agent will not adequately and fairly
reflect the cost to such Banks of funding their Euro-Dollar Loans for such
Interest Period,

the Agent shall forthwith give notice thereof to the Company and the Banks,
whereupon until the Agent notifies the Company that the circumstances giving
rise to such suspension no longer exist, (i) the obligations of the Banks to
make Euro-Dollar Loans or to convert outstanding Loans into Euro-Dollar Loans

<PAGE>   32

shall be suspended and (ii) each outstanding Euro-Dollar Loan shall be converted
into a Base Rate Loan on the last day of the then current Interest Period
applicable thereto. Unless the Company notifies the Agent by telephone
(confirmed in writing) before the date of any Fixed Rate Borrowing for which a
Notice of Borrowing has previously been given that it elects not to borrow on
such date, thereby revoking such Notice of Borrowing, (i) if such Fixed Rate
Borrowing is a Committed Borrowing, such Borrowing shall instead be made as a
Base Rate Borrowing, (ii) if such Fixed Rate Borrowing is a Money Market LIBOR
Borrowing in U.S. Dollars, the Money Market LIBOR Loans comprising such
Borrowing shall bear interest for each day from and including the first day to
but excluding the last day of the Interest Period applicable thereto at the Base
Rate for such day and (iii) if such Fixed Rate Borrowing is a Money Market LIBOR
Borrowing in Canadian Dollars, the Money Market Loans comprising such Borrowing
shall bear interest for each day from and including the first day to but
excluding the last day of the Interest Period applicable thereto at the Canadian
Prime Rate for such day.

         SECTION 8.02. Illegality. If, on or after the date of this Agreement,
the adoption of any applicable law, rule or regulation, or any change in any
applicable law, rule or regulation, or any change in the interpretation or
administration thereof by any governmental authority, central bank or comparable
agency charged with the interpretation or administration thereof, or compliance
by any Bank (or its Euro-Dollar Lending Office) with any request or directive
(whether or not having the force of law, but if not having the force of law, the
compliance with which is in accordance with the general practice of Persons to
whom such request or directive is addressed) of any such authority, central bank
or comparable agency shall make it unlawful or impossible for any Bank (or its
Euro-Dollar Lending Office) to make, maintain or fund its Euro-Dollar Loans to
the Company and such Bank shall so notify the Agent, the Agent shall forthwith
give notice thereof to the other Banks and the Company, whereupon until such
Bank notifies the Company and the Agent that the circumstances giving rise to
such suspension no longer exist, the obligation of such Bank to make Euro-Dollar
Loans to the Company, or to convert outstanding Loans into Euro-Dollar Loans,
shall be suspended. Before giving any notice to the Agent pursuant to this
Section, such Bank shall designate a different Euro-Dollar Lending Office if
such designation will avoid the need for giving such notice and will not, in the
judgment of such Bank, be otherwise materially disadvantageous to such Bank. If
such notice is given, each Euro-Dollar Loan of such Bank then outstanding shall
be converted to a Base Rate Loan either (a) on the last day of the then current
Interest Period applicable to such Euro-Dollar Loan if such Bank may lawfully
continue to maintain and fund such Loan to such day or (b) immediately if such
Bank shall determine that it may not lawfully continue to maintain and fund such
Loan to such day.

          SECTION 8.03. Increased Cost and Reduced Return. (a) If on or after
(x) the date hereof, in the case of any Committed Loan or any obligation to make
Committed Loans or (y) the date of the related Money Market Quote, in the case
of any Money Market Loan, the adoption of any applicable law, rule or
regulation, or any change in any applicable law, rule or regulation, or any
change in the interpretation or administration thereof by any governmental
authority, central bank or comparable agency charged with the interpretation or
administration thereof, or compliance by any Bank (or its Applicable Lending
Office) with any request or directive (whether or not having the force of law,
but if not having the force of law, the compliance with which is in accordance
with the general practice of Persons to whom such request or directive is
addressed) of any such authority, central bank or comparable agency shall
impose, modify or deem applicable any reserve, special deposit, insurance

<PAGE>   33

assessment or similar requirement against assets of, deposits with or for the
account of, or credit extended by, any Bank (or its Applicable Lending Office)
or shall impose on any Bank (or its Applicable Lending Office) or the London
interbank market any other condition affecting its Fixed Rate Loans, its Note or
its obligation to make Fixed Rate Loans and the result of any of the foregoing
is to increase the cost to such Bank (or its Applicable Lending Office) of
making or maintaining any Fixed Rate Loan, or to reduce the amount of any sum
received or receivable by such Bank (or its Applicable Lending Office) under
this Agreement or under its Note with respect thereto, by an amount deemed by
such Bank to be material, then, within 15 days after demand by such Bank (with a
copy to the Agent), the Company shall pay to such Bank such additional amount or
amounts as will compensate such Bank for such increased cost or reduction.

          (b) If any Bank shall have determined that, after the date hereof, the
adoption of any applicable law, rule or regulation regarding capital adequacy,
or any change in any such law, rule or regulation, or any change in the
interpretation or administration thereof by any governmental authority, central
bank or comparable agency charged with the interpretation or administration
thereof, or any request or directive regarding capital adequacy (whether or not
having the force of law, but if not having the force of law, the compliance with
which is in accordance with the general practices of Persons to whom such
request or directive is addressed) of any such authority, central bank or
comparable agency, has or would have the effect of reducing the rate of return
on capital of such Bank (or its Parent) as a consequence of such Bank's
obligations hereunder to a level below that which such Bank (or its Parent)
could have achieved but for such adoption, change, request or directive (taking
into consideration its policies with respect to capital adequacy) by an amount
deemed by such Bank to be material, then from time to time, within 15 days after
demand by such Bank (with a copy to the Agent), the Company shall pay to such
Bank such additional amount or amounts as will compensate such Bank (or its
Parent) for such reduction.

          (c) Each Bank will promptly notify the Company and the Agent of any
event of which it has knowledge, occurring after the date hereof, which will
entitle such Bank to compensation pursuant to this Section and will designate a
different Applicable Lending Office if such designation will avoid the need for,
or reduce the amount of, such compensation and will not, in the judgment of such
Bank, be otherwise materially disadvantageous to such Bank. Any Bank claiming
compensation under this Section shall deliver to the Company, as a condition to
the payment of such compensation, a certificate of an officer of such Bank
setting forth the additional amount or amounts to be paid to it hereunder, which
certificate (x) shall contain reasonable details as to the calculation of such
amount or amounts, provided that such Bank shall not be required to disclose any
information it considers to be confidential, and (y) shall confirm that such
amount or amounts (A) have been calculated on the same basis as the amounts then
being charged by such Bank to its other similarly situated borrowers for the
periods to be covered thereby, (B) are necessary to compensate such Bank for
such additional cost or reduction in return and (C) are compensation for periods
commencing no more than 180 days before the date on which such certificate was
delivered to the Company, plus any period of retroactivity applicable to the
relevant adoption or change. In determining such amount or amounts, such Bank
may use any reasonable averaging and attribution methods. If any element of any
such calculation subsequently changes, so as to change materially such amount or
amounts, such Bank will submit a revised certificate promptly to the Company.

         SECTION 8.04.  Taxes.  (a) For the purposes of this Section 8.04, the
following terms have the following meanings:
<PAGE>   34

         "Taxes" means any and all present or future withholding taxes or
similar duties, levies, imposts, deductions or charges with respect to any
payment by the Company pursuant to this Agreement or under any Note, and all
liabilities with respect thereto, excluding (i) in the case of each Bank and the
Agent, taxes imposed on its income, and franchise or similar taxes imposed on
it, by a jurisdiction under the laws of which such Bank or the Agent (as the
case may be) is organized or in which its principal executive office is located
or, in the case of each Bank, in which its Applicable Lending Office is located
and (ii) in the case of each Bank and the Agent, any Canadian tax imposed on
such payments but only to the extent that such Bank (or with respect to payments
to it for its own account pursuant to Section 7.09, the Agent) is subject to
such Canadian tax at the time such Bank or the Agent (as the case may be) first
becomes a party to this Agreement.

         "Other Taxes" means any present or future Canadian stamp or documentary
taxes and any other Canadian excise or property taxes, or similar Canadian
charges or levies, which arise from any payment made pursuant to this Agreement
or under any Note or from the execution or delivery of, or otherwise with
respect to, this Agreement or any Note.

          (b) Any and all payments by the Company to or for the account of any
Bank or the Agent hereunder or under any Note shall be made without deduction
for any Taxes or Other Taxes; provided that, if the Company shall be required by
law to deduct any Taxes or Other Taxes from any such payments, (i) the sum
payable shall be increased as necessary so that after making all required
deductions (including deductions applicable to additional sums payable under
this Section) such Bank or the Agent (as the case may be) receives an amount
equal to the sum it would have received had no such deductions been made, (ii)
the Company shall make such deductions, (iii) the Company shall pay the full
amount deducted to the relevant taxation authority or other authority in
accordance with applicable law and (iv) the Company shall furnish to such Bank
or the Agent (as the case may be), at its address referred to in Section 9.01,
the original or a certified copy of a receipt evidencing payment thereof.

          (c) The Company agrees to indemnify each Bank and the Agent for the
full amount of Taxes or Other Taxes (including, without limitation, any Taxes or
Other Taxes imposed or asserted on amounts payable under this Section) paid by
such Bank or the Agent (as the case may be) and any liability (including
penalties, interest and expenses arising from the failure of the Company to pay
such Taxes or Other Taxes when due) arising therefrom or with respect thereto,
in each case upon receipt by the Company of documentation reasonably
satisfactory to it concerning the existence and amount of such Taxes, Other
Taxes or liability. This indemnification shall be paid within 15 days after such
Bank or the Agent (as the case may be) makes demand therefor.

          (d) Each Bank organized under the laws of a jurisdiction outside
Canada, on or prior to the date of its execution and delivery of this Agreement
in the case of each such Bank listed on the signature pages hereof and on or
prior to the date on which it becomes a Bank in the case of each other such
Bank, and from time to time thereafter if requested in writing by the Company
(but only so long as such Bank remains lawfully able to do so), shall provide
the Company and the Agent with a certificate of an officer of such Bank stating
that such Bank is entitled to benefits under an income tax treaty to which
Canada is a party which exempts the Bank from Canadian withholding tax or
reduces the rate of withholding tax on payments of interest for the account of
such Bank or certifying that the income receivable pursuant to this Agreement is

<PAGE>   35

effectively connected with the conduct of a trade or business in Canada. If the
Agent is organized under the laws of jurisdiction outside Canada, it shall
likewise provide such a letter with respect to payments of fees for its own
account pursuant to Section 7.09.

          (e) For any period with respect to which a Bank or the Agent has
failed to provide the Company with the appropriate certificate pursuant to
Section 8.04(d) (unless such failure is due to change in treaty, law or
regulation occurring subsequent to the date on which such certificate originally
was required to be provided), such Bank (or with respect to payments to it for
its own account pursuant to Section 7.09, the Agent) shall not be entitled to
indemnification under Section 8.04(b) or (c) with respect to Taxes imposed by
Canada; provided that if a Bank or the Agent, which is otherwise exempt from or
subject to a reduced rate of withholding tax, becomes subject to Taxes because
of its failure to deliver a certificate required hereunder, the Company shall
take such steps as such Bank or the Agent shall reasonably request to assist
such Bank or the Agent to recover such Taxes.

          (f) If the Company is required to pay additional amounts to or for the
account of any Bank pursuant to this Section, then such Bank will change the
jurisdiction of its Applicable Lending Office if, in the judgment of such Bank,
such change (i) will eliminate or reduce any such additional payment which may
thereafter accrue and (ii) is not otherwise disadvantageous to such Bank.

         SECTION 8.05. Base Rate Loans Substituted for Affected Euro-Dollar
Loans. If (i) the obligation of any Bank to make Euro-Dollar Loans to the
Company has been suspended pursuant to Section 8.02 or (ii) any Bank has
demanded compensation under Section 8.03 or 8.04 with respect to its Euro-
Dollar Loans and the Company shall, by at least five Euro-Currency Business
Days' prior notice to such Bank through the Agent, have elected that the
provisions of this Section shall apply to such Bank, then, unless and until such
Bank notifies the Company that the circumstances giving rise to such suspension
or demand for compensation no longer exist:

          (a) all Loans to the Company which would otherwise be made by such
Bank as (or continued as or converted into) Euro-Dollar Loans shall instead be
Base Rate Loans (on which interest and principal shall be payable
contemporaneously with the related Euro-Dollar Loans of the other Banks); and

          (b) after each of its Euro-Dollar Loans to the Company has been repaid
(or converted to a Base Rate Loan), all payments of principal which would
otherwise be applied to repay such Euro-Dollar Loans shall be applied to repay
its Base Rate Loans instead.

         SECTION 8.06. Substitution of Bank. If (i) the obligation of any Bank
to make Euro-Dollar Loans has been suspended pursuant to Section 8.02 or (ii)
any Bank has demanded compensation under Section 8.03 or 8.04, the Company shall
have the right, with the assistance of the Agent, to seek a mutually
satisfactory substitute bank or banks (which may be one or more of the Banks) to
purchase the Note and assume the Commitment of such Bank, which agrees in such
event to sell its Note and transfer its Commitment.



                                    ARTICLE 9
                                  MISCELLANEOUS
<PAGE>   36

         SECTION 9.01. Notices. Except as otherwise expressly provided herein,
all notices, requests and other communications to any party hereunder shall be
in writing (including bank wire, telex, facsimile transmission or similar
writing and, with respect to the reports and other information referred to in
the next sentence, by e-mail or other electronic means) and shall be given to
such party: (a) in the case of the Company or the Agent, at its address,
facsimile number or telex number set forth on the signature pages hereof, (b) in
the case of any Bank, at its address, facsimile number, telex number or e-mail
address set forth in its Administrative Questionnaire or (c) in the case of any
party, such other address, facsimile number, telex number or e-mail address as
such party may hereafter specify for the purpose by notice to the Agent and the
Company. All reports and other information required to be delivered to the Banks
pursuant to Section 5.01(a), (b), (c), (e) or (f) may be delivered by e-mail
(either as an e-mail attachment or by including an appropriate internet link to
such reports or other information). Each such notice, request or other
communication shall be effective (i) if given by telex, when such telex is
transmitted to the telex number specified in this Section and the appropriate
answerback is received, (ii) if given by facsimile transmission, when
transmitted to the facsimile number specified in this Section and confirmation
of receipt is received, (iii) if given by e-mail, when such e-mail is
transmitted to the e-mail addressed specified in this Section, or (iv) if given
by any other means, when delivered at the address specified in this Section;
provided that notices to the Agent under Article 2 or Article 8 shall not be
effective until received.

         SECTION 9.02. No Waivers. No failure or delay by the Agent or any Bank
in exercising any right, power or privilege hereunder or under any Note shall
operate as a waiver thereof nor shall any single or partial exercise thereof
preclude any other or further exercise thereof or the exercise of any other
right, power or privilege. The rights and remedies herein provided shall be
cumulative and not exclusive of any rights or remedies provided by law.

         SECTION 9.03. Expenses; Indemnification. (a) The Company shall pay (i)
all reasonable out-of-pocket expenses of the Agent, including fees and
disbursements of special counsel for the Agent, in connection with the
preparation and administration of this Agreement, any waiver or consent
hereunder or any amendment hereof or any Default or alleged Default hereunder
and (ii) if an Event of Default occurs, all reasonable out-of-pocket expenses
incurred by the Agent and each Bank, including (without duplication) the fees
and disbursements of outside counsel, in connection with such Event of Default
and collection, bankruptcy, insolvency and other enforcement proceedings
resulting therefrom.

          (b) The Company agrees to indemnify the Agent and each Bank, their
respective affiliates and the respective directors, officers, agents and
employees of the foregoing (each an "Indemnitee") and hold each Indemnitee
harmless from and against any and all liabilities, losses, damages, costs and
expenses of any kind, including, without limitation, the reasonable fees and
disbursements of counsel, which may be incurred by such Indemnitee in connection
with any investigative, administrative or judicial proceeding (whether or not
such Indemnitee shall be designated a party thereto) brought or threatened by a
Person which is not a party hereto or an Affiliate of a party hereto relating to
any actual, proposed or potential use of proceeds of Loans hereunder; provided
that no Indemnitee shall have the right to be indemnified hereunder for such
Indemnitee's own gross negligence or willful misconduct as determined by a court
of competent jurisdiction.
<PAGE>   37

         SECTION 9.04. Sharing of Set-offs. Each Bank agrees that if it shall,
by exercising any right of set-off or counterclaim or otherwise, receive payment
of a proportion of the aggregate amount of principal and interest relating to
its Committed Loans which is greater than the proportion received by any other
Bank in respect of the aggregate amount of principal and interest relating to
the Committed Loans of such other Bank, the Bank receiving such proportionately
greater payment shall purchase such participations in the Notes held by the
other Banks, and such other adjustments shall be made, as may be required so
that all such payments of principal and interest relating to Committed Loans of
the Banks shall be shared by the Banks pro rata; provided that nothing in this
Section shall impair the right of any Bank to exercise any right of set-off or
counterclaim it may have and to apply the amount subject to such exercise to the
payment of indebtedness of the Company other than its indebtedness hereunder.

         SECTION 9.05. Amendments and Waivers. Any provision of this Agreement
or the Notes may be amended or waived if, but only if, such amendment or waiver
is in writing and is signed by the Company and the Required Banks (and, if the
rights or duties of the Agent are affected thereby, by the Agent); provided that
no such amendment or waiver shall, unless signed by all the Banks, (i) increase
or decrease the Commitment of any Bank (except for a ratable decrease in the
Commitments of all Banks) or subject any Bank to any additional obligation, (ii)
reduce the principal of or rate of interest on any Loan, or any fees hereunder,
(iii) postpone the date fixed for any payment of principal of or interest on any
Loan, or any fees hereunder or for any scheduled reduction or termination of any
Commitment or (iv) change the percentage of the Commitments or of the aggregate
unpaid principal amount of the Notes, or the number of Banks, which shall be
required for the Banks or any of them to take any action under this Section or
any other provision of this Agreement.

         SECTION 9.06. Successors and Assigns. (a) The provisions of this
Agreement shall be binding upon and inure to the benefit of the parties hereto
and their respective successors and assigns, except that the Company may not
assign or otherwise transfer any of its rights under this Agreement without the
prior written consent of all Banks.

          (b) Any Bank may at any time grant to one or more banks or other
institutions (each a "Participant") participating interests in its Commitment or
any or all of its Loans. In the event of any such grant by a Bank of a
participating interest to a Participant, whether or not upon notice to the
Company and the Agent, such Bank shall remain responsible for the performance of
its obligations hereunder, and the Company and the Agent shall continue to deal
solely and directly with such Bank in connection with such Bank's rights and
obligations under this Agreement. Any agreement pursuant to which any Bank may
grant such a participating interest shall provide that such Bank shall retain
the sole right and responsibility to enforce the obligations of the Company
hereunder including, without limitation, the right to approve any amendment,
modification or waiver of any provision of this Agreement; provided that such
participation agreement may provide that such Bank will not agree to any
modification, amendment or waiver of this Agreement described in clause (i),
(ii), or (iii) of Section 9.05 without the consent of the Participant. The
Company agrees that each Participant shall, to the extent provided in its
participation agreement, be entitled to the benefits of Article 8 with respect
to its participating interest. An assignment or other transfer which is not
permitted by subsection (c) or (d) below shall be given effect for purposes of
this Agreement only to the extent of a participating interest granted in
accordance with this subsection (b).
<PAGE>   38

          (c) Any Bank may at any time assign to one or more banks or other
institutions (each an "Assignee") all, or a proportionate part (equivalent to an
initial Commitment of not less than $10,000,000) of all, of its rights and
obligations under this Agreement and the Notes, and such Assignee shall assume
such rights and obligations, pursuant to an Assignment and Assumption Agreement
in substantially the form of Exhibit G hereto executed by such Assignee and such
transferor Bank, with (and subject to) the subscribed consent of the Company and
the Agent, which shall not be unreasonably withheld; provided that if an
Assignee is an affiliate of such transferor Bank or was a Bank immediately prior
to such assignment, no such consent shall be required; and provided further that
such assignment may, but need not, include rights of the transferor Bank in
respect of outstanding Money Market Loans. Upon execution and delivery of such
instrument and payment by such Assignee to such transferor Bank of an amount
equal to the purchase price agreed between such transferor Bank and such
Assignee, such Assignee shall be a Bank party to this Agreement and shall have
all the rights and obligations of a Bank with a Commitment as set forth in such
instrument of assumption, and the transferor Bank shall be released from its
obligations hereunder to a corresponding extent, and no further consent or
action by any party shall be required. Upon the consummation of any assignment
pursuant to this subsection (c), the transferor Bank, the Agent and the Company
shall make appropriate arrangements so that, if required, a new Note is issued
to the Assignee. In connection with any such assignment, the transferor Bank
shall pay to the Agent an administrative fee for processing such assignment in
the amount of $2,500.

          (d) No Assignee, Participant or other transferee of any Bank's rights
shall be entitled to receive any greater payment under Section 8.03 or 8.04 than
such Bank would have been entitled to receive with respect to the rights
transferred, unless such transfer is made with the Company's prior written
consent or by reason of the provisions of Section 8.02, 8.03 or 8.04 requiring
such Bank to designate a different Applicable Lending Office under certain
circumstances or at a time when the circumstances giving rise to such greater
payment did not exist.

         SECTION 9.07. Collateral. Each of the Banks represents to the Agent and
each of the other Banks that it in good faith is not relying upon any "margin
stock" (as defined in Regulation U) as collateral in the extension or
maintenance of the credit provided for in this Agreement.

         SECTION 9.08. Governing Law; Submission to Jurisdiction. This Agreement
and each Note shall be governed by and construed in accordance with the laws of
the State of New York. The Company hereby submits to the nonexclusive
jurisdiction of the United States District Court for the Southern District of
New York and of any New York State court sitting in New York City for purposes
of all legal proceedings arising out of or relating to this Agreement or the
transactions contemplated hereby. The Company irrevocably waives, to the fullest
extent permitted by law, any objection which it may now or hereafter have to the
laying of the venue of any such proceeding brought in such a court and any claim
that any such proceeding brought in such a court has been brought in an
inconvenient forum.

         SECTION 9.09. Counterparts; Integration; Effectiveness. This Agreement
may be signed in any number of counterparts, each of which shall be an original,
with the same effect as if the signatures thereto and hereto were upon the same
instrument. This Agreement constitutes the entire agreement and understanding
among the parties hereto and supersedes any and all prior agreements and
understandings, oral or written, relating to the subject matter hereof. This

<PAGE>   39

Agreement shall become effective upon receipt by the Agent of counterparts
hereof signed by each of the Company, the Banks and the Agent (or, in the case
of any party as to which an executed counterpart shall not have been received,
receipt by the Agent in form satisfactory to it of telegraphic, telex, facsimile
or other written confirmation from such party of execution of a counterpart
hereof by such party).

         SECTION 9.10. WAIVER OF JURY TRIAL. EACH OF THE COMPANY, THE AGENT AND
THE BANKS HEREBY IRREVOCABLY WAIVES ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY
LEGAL PROCEEDING ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE
TRANSACTIONS CONTEMPLATED HEREBY.

         SECTION 9.11. Confidentiality. The Agent and each Bank agree to keep
confidential any information obtained by the Agent or such Bank from the Company
to the extent such information has been stated by the Company to be
confidential, provided that nothing herein shall prevent the Agent or any Bank
from disclosing such information (i) to the Agent or any other Bank in
connection with the transactions contemplated by this Agreement, (ii) to its
officers, directors, employees, Affiliates, agents, attorneys and accountants
who have a need to know such information in accordance with customary banking
practices and who receive such information having been made aware of the
restrictions set forth in this Section, (iii) upon the order of any court or
administrative agency, (iv) upon the request or demand of any regulatory agency
or authority having jurisdiction over such party, (v) which has been publicly
disclosed, (vi) which has been obtained from any Person other than the Company
and its Affiliates, provided that such Person is not known to it to be bound by
a confidentiality agreement with the Company or its Affiliates or known to it to
be otherwise prohibited from transmitting the information to it by a
contractual, legal or fiduciary obligation or (vii) in connection with the
exercise of any remedy hereunder in any judicial proceeding.

         SECTION 9.12. Termination of Existing Credit Agreements. The Company
and each of the Banks that is also a "Bank" party to the Existing Credit
Agreements agrees that the "Commitments" as defined in the Existing Credit
Agreements shall be terminated in their entirety on the Effective Date. Each of
such Banks and J.P. Morgan Canada, as agent under the Existing Credit
Agreements, waives (a) any requirement of notice of such termination pursuant to
Section 2.09 of the Existing Credit Agreements and (b) any claim to any facility
fees under the Existing Credit Agreements for any day on or after the Effective
Date. The Company (i) represents and warrants that (x) after giving effect to
the preceding sentences of this Section 9.12, the commitments under the Existing
Credit Agreements will be terminated effective not later than the Effective
Date, and (y) no loans are, as of the date hereof, or will be, as of the
Effective Date, outstanding under the Existing Credit Agreements and (ii)
covenants that all accrued and unpaid facility fees and any other amounts due
and payable under the Existing Credit Agreements shall have been paid on or
prior to the Effective Date.

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed by their respective authorized officers as of the day and year
first above written.

                                      NORTEL NETWORKS CORPORATION


                                      By /s/ K.B. Stevenson
                                         ------------------------------
                                         Title: Treasurer


                                      By /s/ Blair F. Morrison
                                         ------------------------------
                                         Title: Assistant Secretary

                                      Address: 8200 Dixie Road, Suite 100
                                      Brampton, Ontario L6T 5P6
                                      Facsimile: (905) 863-8258
                                      Attention: Treasurer

<PAGE>   40

                                      BANKS

         By signing below, each Bank confirms that it is organized under the
laws of Canada.

Commitments

$24,625,000                                 J.P. MORGAN CANADA


                                            By: /s/ John Maynard
                                                --------------------------------
                                                Title: Vice President &
                                                Controller


$10,625,000                                 ABN AMRO BANK CANADA


                                            By: /s/ Yvon J. Jeghers
                                                --------------------------------
                                                Title: Group Vice President


                                            By: /s/ David Moore
                                                --------------------------------
                                                Title: Vice President


$10,625,000                                 BANK OF AMERICA CANADA


                                            By: /s/ Richard J. Hall
                                                --------------------------------
                                                Title: Vice President


$10,625,000                                 CITIBANK CANADA


                                            By: /s/ Samuel Shih
                                                --------------------------------
                                                Title: Vice President


$25,000,000                                 ROYAL BANK OF CANADA


                                            By: /s/ Tom Fairbrother
                                                --------------------------------
                                                Title: Senior Account Manager


$25,000,000                                 TORONTO DOMINION BANK


                                            By: /s/ Grant Wice
                                                --------------------------------
                                                Title: Vice President


$9,500,000                                  THE BANK OF NOVA SCOTIA


                                            By: /s/ Mike House
                                                --------------------------------
                                                Title: Director


                                            By: /s/ Paul Sun
                                                --------------------------------
                                                Title: Associate


$9,500,000                                  BANK OF TOKYO - MITSUBISHI
                                                 (CANADA)


                                            By: /s/ D.C.A. Frost
                                                --------------------------------
                                                Title: Senior Vice President


$9,500,000                                  THE CHASE MANHATTAN BANK
                                                 OF CANADA


                                            By: /s/ Christine Chan
                                                --------------------------------
                                                Title: Vice President

                                            By: /s/ Ed Sustar
                                                --------------------------------
                                                Title: Vice President


$9,500,000                                  CREDIT SUISSE FIRST BOSTON
                                                 CANADA


                                            By: /s/ Alain Daoust
                                                --------------------------------
                                                Title: Director


                                            By: /s/ Peter Chauvin
                                                --------------------------------
                                                Title: Vice President


$9,500,000                                  HSBC BANK CANADA

                                            By: /s/ Andrew J. Gregg
                                                --------------------------------
                                                Title: Senior Manager


                                            By: /s/ Peter Leenaars
                                                --------------------------------
                                                Title: Senior Manager


$9,500,000                                  DEUTSCHE BANK CANADA


                                            By: /s/ Robert A. Johnston
                                                --------------------------------
                                                Title: Vice President


                                            By: /s/ Paul Jurist
                                                --------------------------------
                                                Title: Director


$20,000,000                                 SOCIETE GENERALE (CANADA)


                                            By: /s/ Georges Benay
                                                --------------------------------
                                                Title: Director, Corporate
                                                       Finance


$8,250,000                                  BANK OF MONTREAL


                                            By: /s/ D. Friedman
                                                --------------------------------
                                                Title: Director


$8,250,000                                  THE INDUSTRIAL BANK OF JAPAN
                                                 (CANADA)


                                            By: /s/ Nigel Sharpley
                                                --------------------------------
                                                Title: Vice President


$22,500,000                                 CANADIAN IMPERIAL BANK OF
                                                 COMMERCE


                                            By: /s/ A.J. Waller
                                                --------------------------------
                                                Title: Executive Director



$22,500,000                                 NATIONAL BANK OF CANADA


                                            By: /s/ Anne Brown
                                                --------------------------------
                                                Title: Manager


                                            By: /s/ Ian Gillespie
                                                --------------------------------
                                                Title: Manager



$5,000,000                                  THE SUMITOMO BANK OF CANADA


                                            By: /s/ Alfred Lee
                                                --------------------------------
                                                Title: Vice President



Total Commitments
$250,000,000


                                            ROYAL BANK OF CANADA,
                                              as Co-Syndication Agent

                                            By: /s/ Tom Fairbrother
                                                --------------------------------
                                                Title: Manager



                                            TORONTO DOMINION BANK
                                              as Co-Syndication Agent

                                            By: /s/ Grant Wice
                                                --------------------------------
                                                Title: Vice President


                                            J.P. MORGAN CANADA,
                                              as Administrative Agent

                                            By: /s/ John Maynard
                                                --------------------------------
                                                Title: Vice President &
                                                       Controller
                                              Address: Royal Bank Plaza
                                              South Tower
                                              22nd Floor
                                              Toronto, Ontario
                                              M5J 2J2
                                              Facsimile: (416) 981-9278

<PAGE>   41

                                PRICING SCHEDULE

         Each of "Euro-Dollar Margin" and "Facility Fee Rate" means, for any
date, the rate set forth below in the row opposite such term and in the column
corresponding to the "Pricing Level" that applies at such date:

<TABLE>
<CAPTION>

                        Level I    Level II    Level III    Level IV    Level V
                       ---------  ----------  -----------  ----------  ---------
<S>                      <C>        <C>          <C>         <C>         <C>
Euro-Dollar
Margin:
   Utilization <= 25%    0.09%      0.1175%      0.17%       0.30%       0.50%
   Utilization > 25%     0.14%      0.1675%      0.22%       0.40%       0.625%
Facility Fee
Rate                     0.06%      0.07%        0.08%       0.10%       0.125%
</TABLE>


         For purposes of this Schedule, the following terms have the following
meanings:

         "Level I Pricing" applies at any date if, at such date, the Company's
long- term debt is rated AA- or higher by S&P or Aa3 or higher by Moody's.

         "Level II Pricing" applies at any date if, at such date, (i) the
Company's long-term debt is rated A or higher by S&P or A2 or higher by Moody's,
and (ii) Level I Pricing does not apply.

         "Level III Pricing" applies at any date if, at such date, (i) the
Company's long-term debt is rated A- or higher by S&P or A3 or higher by Moody's
and (ii) neither Level I Pricing nor Level II Pricing applies.

         "Level IV Pricing" applies at any date, if at such date, (i) the
Company's long-term debt is rated BBB+ or higher by S&P or Baa1 by Moody's and
(ii) none of Level I Pricing, Level II Pricing or Level III Pricing applies.

         "Level V Pricing" applies at any date if, at such date, none of Level I
Pricing, Level II Pricing, Level III Pricing or Level IV Pricing applies.

         "Moody's" means Moody's Investors Service, Inc.

         "Pricing Level" refers to the determination of which of Level I, Level
II, Level III, Level IV or Level V applies at any date.

         "S&P" means Standard & Poor's Ratings Services, a division of The
McGraw-Hill Companies, Inc.

         "Utilization" means, on any day, the percentage equivalent of a
fraction, (i) the numerator of which is the aggregate outstanding principal
amount of the Loans on such day, after giving effect to any borrowing or payment
on such day, and (ii) the denominator of which is the aggregate amount of the
Commitments on such day, after giving effect to any reduction of the Commitments
on such day.

         The credit ratings to be utilized for purposes of this Schedule are
those assigned to the senior unsecured long-term debt securities of the Company
without third-party credit enhancement, and any rating assigned to any other
debt security of the Company shall be disregarded. The rating in effect at any
date is that in effect at the close of business on such date.

<PAGE>   42
                                                                EXHIBIT A - Note

                                      NOTE

                                                     Toronto, Canada
                                                     ___________ __, 2000

         For value received, NORTEL NETWORKS CORPORATION, a Canadian corporation
(the "Borrower"), promises to pay to the order of ______________________ (the
"Bank"), for the account of its Applicable Lending Office, the unpaid principal
amount of each Loan made by the Bank to the Borrower pursuant to the Credit
Agreement referred to below on the maturity date specified therefor in the
Credit Agreement. The Borrower promises to pay interest on the unpaid principal
amount of each such Loan on the dates and at the rate or rates provided for in
the Credit Agreement. All such payments of principal and interest shall be made
in funds immediately available in Toronto, at the office of J.P. Morgan Canada,
Royal Bank Plaza, South Tower, Toronto, Ontario M5J 2J2.

         All Loans made by the Bank, the respective currencies, types and
maturities thereof and all repayments of the principal thereof shall be recorded
by the Bank and, if the Bank so elects in connection with any transfer or
enforcement hereof, appropriate notations to evidence the foregoing information
with respect to each such Loan then outstanding may be endorsed by the Bank on
the schedule attached hereto, or on a continuation of such schedule attached to
and made a part hereof; provided that the failure of the Bank to make any such
recordation or endorsement shall not affect the obligations of the Borrower
hereunder or under the Credit Agreement.

         This note is one of the Notes referred to in the Five Year Credit
Agreement dated as of April 12, 2000 among Nortel Networks Corporation, the
banks and co-syndication agents parties thereto and J.P. Morgan Canada, as
Administrative Agent (as the same may be amended from time to time, the "Credit
Agreement"). Terms defined in the Credit Agreement are used herein with the same
meanings. Reference is made to the Credit Agreement for provisions for the
prepayment hereof and the acceleration of the maturity hereof.

                                            NORTEL NETWORKS CORPORATION

                                            By
                                               ----------------------------
                                               Name:
                                               Title:

                                            By
                                               ----------------------------
                                               Name:
                                               Title:

<PAGE>   43

<TABLE>
<CAPTION>


                         LOANS AND PAYMENTS OF PRINCIPAL
--------------------------------------------------------------------------------
            Currency
               and
             Amount         Type         Amount of
               of            of          Principal       Maturity       Notation
Date          Loan          Loan          Repaid           Date          Made By
-----      ----------      ------       -----------     ----------     ---------
<S>          <C>            <C>          <C>              <C>            <C>
--------------------------------------------------------------------------------

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

--------------------------------------------------------------------------------
</TABLE>

<PAGE>   44
                                          EXHIBIT B - Money Market Quote Request

                       Form of Money Market Quote Request

                                                           [Date]


To:        J.P. Morgan Canada, as Administrative Agent (the "Agent")
From:      Nortel Networks Corporation
Re:        Five Year Credit Agreement (as amended from time to time, the "Credit
           Agreement") dated as of April 12, 2000 among Nortel Networks
           Corporation, the Banks and Co-Syndication Agents parties thereto and
           the Agent

           We hereby give notice pursuant to Section 2.03 of the Credit
Agreement that we request Money Market Quotes for the following proposed Money
Market Borrowing(s):

Date of Borrowing:  __________________

<TABLE>
<CAPTION>
Principal Amount(1)           Currency(2)                 Interest Period(3)
-------------------          --------------             ----------------------
<S>                           <C>                           <C>
$
</TABLE>

           Such Money Market Quotes should offer a Money Market [Margin]
[Absolute Rate]. [The applicable base rate is the London Interbank Offered
Rate.]

           Terms used herein have the meanings assigned to them in the Credit
Agreement.

                                                NORTEL NETWORKS CORPORATION

                                                By
                                                   -----------------------------
                                                   Name:
                                                   Title:

                                                By
                                                   -----------------------------
                                                   Name:
                                                   Title:

------------
(1) Amount must be $25,000,000 or C$25,000,000 or a larger multiple of
$5,000,000 or C$5,000,000.

(2) Currency must be U.S. Dollars or Canadian Dollars.

(3) Not less than one month (LIBOR Auction) or not less than 14 days
(Absolute Rate Auction), subject to the provisions of the definition of Interest
Period.

<PAGE>   45
                                  EXHIBIT C - Invitation for Money Market Quotes



                   Form of Invitation for Money Market Quotes


To:        [Name of Bank]
Re:        Invitation for Money Market Quotes to Nortel Networks Corporation
           (the "Borrower")

           Pursuant to Section 2.03 of the Five Year Credit Agreement dated as
of April 12, 2000 among Nortel Networks Corporation, the Banks and
Co-Syndication Agents parties thereto and the undersigned, as Administrative
Agent, as amended from time to time, we are pleased on behalf of the Borrower to
invite you to submit Money Market Quotes to the Borrower for the following
proposed Money Market Borrowing(s):

Date of Borrowing:  __________________

<TABLE>
<CAPTION>
Principal Amount                 Currency                 Interest Period
----------------                ----------               -----------------
<S>                              <C>                        <C>
$
</TABLE>

           Such Money Market Quotes should offer a Money Market [Margin]
[Absolute Rate]. [The applicable base rate is the London Interbank Offered
Rate.] Please respond to this invitation by no later than [10:00 A.M.] [9:30
A.M.] (Toronto time) on [date].

                                             J.P. MORGAN CANADA, as
                                             Administrative Agent

                                             By
                                                --------------------------
                                                Authorized Officer

<PAGE>   46
                                                  EXHIBIT D - Money Market Quote


                           Form of Money Market Quote

To:        J.P. Morgan Canada, as Administrative Agent
Re:        Money Market Quote to Nortel Networks Corporation (the "Borrower")

           In response to your invitation on behalf of the Borrower dated
_____________,____, we hereby make the following Money Market Quote on the
following terms:

1.   Quoting Bank:  ________________________________
2.   Person to contact at Quoting Bank:_____________________________
3.   Date of Borrowing: ____________________*
4.   Currency of Borrowing: ____________________**
5.   We hereby offer to make Money Market Loan(s) in the following principal
     amounts, for the following Interest Periods and at the following rates:

<TABLE>
<CAPTION>
Principal         Interest      Money Market
Amount***         Period****   [Margin*****]     [Absolute Rate******]
---------         ----------   -------------     ----------------------
<S>                <C>           <C>              <C>
$

$
</TABLE>

     [Provided, that the aggregate principal amount of Money Market Loans for
which the above offers may be accepted shall not exceed $____________.]**

----------
* As specified in the related Invitation.
** Currency must be U.S. Dollars or Canadian Dollars.
*** Principal amount bid for each Interest Period may not exceed principal
amount requested. Specify aggregate

                      (notes continued on following page)

<PAGE>   47

     We understand and agree that the offer(s) set forth above, subject to the
satisfaction of the applicable conditions set forth in the Five Year Credit
Agreement dated as of April 12, 2000 among Nortel Networks Corporation, the
Banks and Co-Syndication Agents parties thereto and yourselves, as
Administrative Agent, as amended from time to time, irrevocably obligates us to
make the Money Market Loan(s) for which any offer(s) are accepted, in whole or
in part.

                                           Very truly yours,

                                           [NAME OF BANK]

Dated:                                     By:
       ----------------                        ------------------------
                                               Authorized Officer

----------
limitation if the sum of the individual offers exceeds the amount the Bank is
willing to lend. Bids must be made for $5,000,000 or C$5,000,000 or a larger
multiple of $1,000,000 or C$1,000,000.
**** Not less than one month or not less 14 days, as specified in the related
Invitation. No more than five bids are permitted for each Interest Period.
***** Margin over or under the London Interbank Offered Rate determined for the
applicable Interest Period. Specify percentage (to the nearest 1/10,000 of 1%)
and specify whether "PLUS" or "MINUS".
****** Specify rate of interest per annum (to the nearest 1/10,000th of 1%).

<PAGE>   48
                                  EXHIBIT E - Opinion of Counsel for the Company


                                   OPINION OF
                             COUNSEL FOR THE COMPANY

                                                   ________________, 2000

To the Banks and the Administrative Agent
Referred to Below
c/o J.P. Morgan Canada, as Administrative Agent
[Royal Bank Plaza, South Tower,
22nd Floor
Toronto, Ontario  M5J 2J2]

Dear Sirs:

         I am Chief Legal Officer of Nortel Networks Corporation (the
"Corporation") and give this opinion pursuant to Section 3.01(b) of the Five
Year Credit Agreement (the "Credit Agreement") dated as of April 12, 2000 among
the Corporation, the banks and co-syndication agents parties thereto and J.P.
Morgan Canada, as Administrative Agent. Terms defined in the Credit Agreement
are used herein as therein defined.

         I have examined originals or copies, certified or otherwise identified
to my satisfaction, of such documents, corporate records, certificates of public
officials and other instruments and have conducted such other investigations of
fact and law as I have deemed necessary or advisable for purposes of this
opinion.

         In rendering this opinion, I have assumed:

         (a) the signatures on the documents I have examined are originals; and

         (b) with respect to the valid and binding nature of the Credit
Agreement and the delivery of the Credit Agreement, the laws of the State of New
York are the same as the laws of Canada.

         The opinions expressed herein are subject to the following
qualifications:

         (a) enforceability of the Credit Agreement and the Notes may be limited
by bankruptcy, insolvency, or other laws affecting the enforcement of creditors'
rights generally;

         (b)  equitable remedies, including remedies of specific performance and
injunction, may only be granted in the discretion of a court of competent
jurisdiction;

         (c) the Currency Act (Canada) precludes the courts in Canada from
awarding a judgment for an amount expressed in a currency other than Canadian
dollars; and
<PAGE>   49

         (d) any requirement to pay interest at a greater rate after than before
default may not be enforceable if the same is construed by a court to constitute
a penalty.

         In expressing the opinions in paragraphs 1, 2 and 3 stated below, I
have relied exclusively upon the opinion of ____________________,
_______________________________ of the Corporation, dated the date hereof (the
"Opinion"), a copy of which is attached hereto as Schedule A. The opinions
expressed herein are limited in scope to the matters addressed in the Opinion,
and to the extent any such opinion is stated to be based on any assumption or to
be given in reliance on any certificate or other document or to be subject to
any limitation, qualification or exemption, the opinions expressed herein in
reliance on such opinion are based upon the same assumption, are given in
reliance on the same certificate or document, and are subject to the same
limitation, qualification or exemption. I have reviewed the Opinion and found it
to be satisfactory in form and scope to address the matter for which it has been
relied upon by me herein.

         Upon the basis of the foregoing, I am of the opinion that:

         1. The Corporation is a corporation duly incorporated and validly
existing under the laws of Canada and has all corporate powers and all
governmental licenses, authorizations, consents and approvals required to carry
on its business as now conducted, the absence of which would have a material
adverse effect on the ability of the Corporation to perform its obligations
under the Credit Agreement.

         2. The execution, delivery and performance by the Corporation of the
Credit Agreement and the Notes (i) are within the Corporation's corporate powers
and have been duly authorized by all necessary corporate action, (ii) require no
action by or in respect of, or filing with, any governmental body, agency or
official, and (iii) do not contravene any provision of applicable law or
regulation or any provision of the certificate of incorporation or by-laws of
the Corporation or any contractual restriction, order, decree or other
instrument binding upon the Corporation or any of its Subsidiaries, except in
the case of (ii) and (iii) above, any such action, filing or contravention which
would not have a material adverse effect on the ability of the Corporation to
perform its obligations under the Credit Agreement.

         3. The Credit Agreement constitutes a valid and binding agreement of
the Corporation, and each Note constitutes a valid and binding obligation of the
Corporation, in each case enforceable in accordance with its terms.

         4. To the best of my knowledge, there is no action, suit or proceeding
pending or threatened against or affecting the Corporation or any of its
Subsidiaries before any court or arbitrator or any governmental body, agency or
official, in which there is a reasonable possibility of an adverse decision
which could have a material adverse effect on the ability of the Corporation to
perform its obligations under the Credit Agreement, or which in any manner draws
into question the validity of the Credit Agreement or the Notes.


                                               Yours truly,

                                               Nicholas J. DeRoma
                                               Chief Legal Officer

<PAGE>   50
                                                                      Schedule A

Nortel Networks Corporation
8200 Dixie Road, Suite 100
Dept. 0019, GMS 036/NO/172
Brampton, Ontario Canada L6T 5P6
Tel:
Fax:
E-mail:
www.nortelnetworks.com






April __, 2000



Mr. N.J. DeRoma
Chief Legal Officer
Nortel Networks Corporation
8200 Dixie Road, Suite 100
Brampton, Ontario
L6T 5P6

Dear Sir:

I am ______________________________ of Nortel Networks Corporation (the
"Corporation"). I understand that you will rely on this opinion letter in
connection with the delivery of your opinion pursuant to Section 3.01(b) of the
Credit Agreement dated as of April 12, 2000 among the Corporation, the banks
(the "Banks") and co-syndication agents parties thereto and J.P. Morgan Canada,
as Administrative Agent (the "Credit Agreement"). Terms defined in the Credit
Agreement are used herein as therein defined.

I have examined originals or copies, certified or otherwise identified to my
satisfaction, of such documents, corporate records, certificates of public
officials and other instruments and have conducted such other investigations of
fact and law as I have deemed necessary or advisable for purposes of this
opinion.

In rendering this opinion, I have assumed:

(a)  the signatures on the documents I have examined are originals; and

(b)  with respect to the valid and binding nature of the Credit Agreement and
     the Notes and the delivery of the Credit Agreement, the laws of the State
     of New York are the same as the laws of Canada.

I am qualified to practice law solely in the Province of Ontario, Canada and
express no opinion as to any laws or matters governed by any laws other than the
laws of the Province of Ontario and the federal laws of Canada applicable
therein.
<PAGE>   51

The opinions expressed herein are subject to the following qualifications:

(a)  enforceability of the Credit Agreement and the Notes may be limited by
     bankruptcy, insolvency, or other laws affecting the enforcement of
     creditors' rights generally;

(b)  equitable remedies, including remedies of specific performance and
     injunction, may only be granted in the discretion of a court of competent
     jurisdiction;

(c)  the Currency Act (Canada) precludes the courts in Canada from awarding a
     judgment for an amount expressed in a currency other than Canadian dollars;
     and

(d)  any requirement to pay interest at a greater rate after than before default
     may not be enforceable if the same is construed by a court to constitute a
     penalty.

Upon the basis of the foregoing, I am of the opinion that:

(a)  the Corporation is a corporation duly incorporated and validly existing
     under the laws of Canada and has all corporate powers and all governmental
     licenses, authorizations, consents and approvals required to carry on its
     business as now conducted, the absence of which would have a material
     adverse effect on the ability of the Corporation to perform its obligations
     under the Credit Agreement;

(b)  the execution, delivery and performance by the Corporation of the Credit
     Agreement and the Notes (i) are within the Corporation's corporate powers
     and have been duly authorized by all necessary corporate action, (ii)
     require no action by or in respect of, or filing with, any governmental
     body, agency or official, and (iii) do not contravene any provision of
     applicable law or regulation or any provision of the certificate of
     incorporation or by-laws of the Corporation or any contractual restriction,
     order, decree or other instrument binding upon the Corporation or any of
     its Subsidiaries, except in the case of (ii) and (iii) above, any such
     action, filing or contravention which would not have a material adverse
     effect on the ability of the Corporation to perform its obligations under
     the Credit Agreement;

(c)  the Credit Agreement constitutes a valid and binding agreement of the
     Corporation, and each Note constitutes a valid and binding obligation of
     the Corporation, in each case enforceable in accordance with its terms; and

(d)  to be best of my knowledge, there is no action, suit or proceeding pending
     or threatened against or affecting the Corporation or any of its
     Subsidiaries before any court or arbitrator or any governmental body,
     agency or official, in which there is a reasonable possibility of an
     adverse decision which could have a material adverse effect on the ability
     of the Corporation to perform its obligations under the Credit Agreement,
     or which in any manner would draw into question the validity of the Credit
     Agreement or the Notes.

This opinion is furnished solely for your benefit in connection with the
aforementioned delivery of your opinion letter (including as an attachment to
your opinion) in connection with the Credit Agreement and is not to be used,
circulated or quoted or otherwise referred to for any other purpose.

                                            Yours truly,
<PAGE>   52


             EXHIBIT F - Opinion of Special Counsel for the Administrative Agent


                                   OPINION OF
                     DAVIS POLK & WARDWELL, SPECIAL COUNSEL
                          FOR THE ADMINISTRATIVE AGENT


________________, 2000

To the Banks and the Agent
Referred to Below
c/o J.P. Morgan Canada, as Administrative Agent
Royal Bank Plaza, South Tower,
22nd Floor
Toronto, Ontario  M5J 2J2

Dear Sirs:

         We have participated in the preparation of the Five Year Credit
Agreement (the "Credit Agreement") dated as of April 12, 2000 among Nortel
Networks Corporation (the "Company"), the banks (the "Banks") and Co-Syndication
Agents parties thereto and J.P. Morgan Canada, as Administrative Agent (the
"Agent"), and have acted as special counsel for the Agent for the purpose of
rendering this opinion pursuant to Section 3.01(c) of the Credit Agreement.
Terms defined in the Credit Agreement are used herein as therein defined.

         We have examined originals or copies, certified or otherwise identified
to our satisfaction, of such documents, corporate records, certificates of
public officials and other instruments and have conducted such other
investigations of fact and law as we have deemed necessary or advisable for
purposes of this opinion.

         Upon the basis of the foregoing, we are of the opinion that, assuming
that the execution, delivery and performance by the Company of the Credit
Agreement and the Notes are within the Company's corporate powers and have been
duly authorized by all necessary corporate action, the Credit Agreement
constitutes a valid and binding agreement of the Company and each Note
constitutes a valid and binding obligation of the Company, in each case
enforceable in accordance with its terms except as the same may be limited by
bankruptcy, insolvency or similar laws affecting creditors' rights generally and
by general principles of equity.

         We are members of the Bar of the State of New York and the foregoing
opinion is limited to the laws of the State of New York. In giving the foregoing
opinion, we express no opinion as to the effect (if any) of any law of any
jurisdiction (except the State of New York) in which any Bank is located which
limits the rate of interest that such Bank may charge or collect.

         This opinion is rendered solely to you in connection with the above
matter. This opinion may not be relied upon by you for any other purpose or
relied upon by any other person without our prior written consent.

                                            Very truly yours,




<PAGE>   53
                                 EXHIBIT G - Assignment and Assumption Agreement



                       ASSIGNMENT AND ASSUMPTION AGREEMENT



         AGREEMENT dated as of _________,____ among <NAME OF ASSIGNOR> (the
"Assignor"), <NAME OF ASSIGNEE> (the "Assignee"), [NORTEL NETWORKS CORPORATION
(the "Company"), and J.P. MORGAN CANADA, as Administrative Agent (the "Agent")].

         WHEREAS, this Assignment and Assumption Agreement (the "Agreement")
relates to the Five Year Credit Agreement dated as of April 12, 2000 among the
Company, the Assignor and the other Banks and Co-Syndication Agents party
thereto, and the Agent (as amended from time to time, the "Credit Agreement");

         [WHEREAS, as provided under the Credit Agreement, the Assignor has a
Commitment to make Committed Loans to the Company in an aggregate principal
amount at any time outstanding not to exceed $__________;]

         WHEREAS, Committed Loans made to the Company by the Assignor under the
Credit Agreement in the aggregate principal amount of $__________ are
outstanding at the date hereof; and

         WHEREAS, the Assignor proposes to assign to the Assignee all of the
rights of the Assignor under the Credit Agreement in respect of a portion of its
[Commitment thereunder in an amount equal to $__________ (the "Assigned
Amount"), together with a corresponding portion of its outstanding Committed
Loans,] [outstanding Committed Loans in an aggregate principal amount equal to
$______ (the "Assigned Amount")](1) and the Assignee proposes to accept
assignment of such rights and assume the corresponding obligations from the
Assignor on such terms;

         NOW, THEREFORE, in consideration of the foregoing and the mutual
agreements contained herein, the parties hereto agree as follows:

         SECTION 1. Definitions. All capitalized terms not otherwise defined
herein shall have the respective meanings set forth in the Credit Agreement.


--------
(1)  Use second variation if Commitments have terminated.


         SECTION 2. Assignment. The Assignor hereby assigns and sells to the
Assignee all of the rights of the Assignor under the Credit Agreement to the
extent of the Assigned Amount, and the Assignee hereby accepts such assignment
from the Assignor and assumes all of the obligations of the Assignor under the
Credit Agreement to the extent of the Assigned Amount, including the purchase
from the Assignor of the corresponding portion of the principal amount of the
Committed Loans made by the Assignor outstanding at the date hereof. Upon the

<PAGE>   54

execution and delivery hereof by the Assignor, the Assignee, [the Company and
the Agent] and the payment of the amounts specified in Section 3 required to be
paid on the date hereof (i) the Assignee shall, as of the date hereof, succeed
to the rights and be obligated to perform the obligations of a Bank under the
Credit Agreement with [a Commitment] [outstanding Committed Loans](1) in an
amount equal to the Assigned Amount, and (ii) the [Commitment] [outstanding
Committed Loans](1) of the Assignor shall, as of the date hereof, be reduced by
a like amount and the Assignor released from its obligations under the Credit
Agreement to the extent such obligations have been assumed by the Assignee. The
assignment provided for herein shall be without recourse to the Assignor.

         SECTION 3. Payments. As consideration for the assignment and sale
contemplated in Section 2 hereof, the Assignee shall pay to the Assignor on the
date hereof in Federal funds the amount heretofore agreed between them. It is
understood that facility fees accrued to the date hereof with respect to the
Assigned Amount are for the account of the Assignor and such fees accruing from
and including the date hereof with respect to the Assigned Amount are for the
account of the Assignee. Each of the Assignor and the Assignee hereby agrees
that if it receives any amount under the Credit Agreement which is for the
account of the other party hereto, it shall receive the same for the account of
such other party to the extent of such other party's interest therein and shall
promptly pay the same to such other party.

         [SECTION 4. Consent of the Company and the Agent. This Agreement is
conditioned upon the consent of the Company and the Agent pursuant to Section
9.06(c) of the Credit Agreement. The execution of this Agreement by the Company
and the Agent is evidence of this consent. Pursuant to Section 9.06(c), the
Company agrees to execute and deliver a Note payable to the order of the
Assignee to evidence the assignment and assumption provided for herein.]

--------
(1)  Use second variation if Commitments have terminated.


         SECTION 5. Non-Reliance on Assignor. The Assignor makes no
representation or warranty in connection with, and shall have no responsibility
with respect to, the solvency, financial condition, or statements of the
Company, or the validity and enforceability of the obligations of the Company in
respect of the Credit Agreement or any Note. The Assignee acknowledges that it
has, independently and without reliance on the Assignor, and based on such
documents and information as it has deemed appropriate, made its own credit
analysis and decision to enter into this Agreement and will continue to be
responsible for making its own independent appraisal of the business, affairs
and financial condition of the Company.

         SECTION 6.  Governing Law.  This Agreement shall be governed by and
construed in accordance with the laws of the State of New York.

         SECTION 7. Counterparts. This Agreement may be signed in any number of
counterparts, each of which shall be an original, with the same effect as if the
signatures thereto and hereto were upon the same instrument.

         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed and delivered by their duly authorized officers as of the date first
above written.

<PAGE>   55

                                            <NAME OF ASSIGNOR>

                                            By
                                                --------------------------------
                                                Name:
                                                Title:


                                            <NAME OF ASSIGNEE>

                                            By
                                                --------------------------------
                                                Name:
                                                Title:


                                            [NORTEL NETWORKS CORPORATION

                                            By
                                                --------------------------------
                                                Name:
                                                Title:

                                            By
                                                --------------------------------
                                                Name:
                                                Title:



                                            J.P. MORGAN CANADA, as
                                                 Administrative Agent

                                            By
                                                --------------------------------
                                                Name:
                                                Title:             ](2)


--------
(2)  omit if consents not required

<PAGE>   56
                                                 EXHIBIT H - Extension Agreement


                               EXTENSION AGREEMENT



Nortel Networks Corporation
[address]

J.P. Morgan Canada, as Administrative Agent
under the Credit Agreement
referred to below
Royal Bank Plaza, South Tower,
22nd Floor,
Toronto, Ontario  M5J 2J2

Gentlemen:

         The undersigned hereby agree to extend, effective [Extension Date], the
Termination Date of each Bank listed herein under the Five Year Credit Agreement
dated as of April 12, 2000 among Nortel Networks Corporation, the Banks [and
Co-Syndication Agents] parties thereto and J.P. Morgan Canada, as Agent (the
"Credit Agreement") for one year to [date to which the Termination Date is
extended]. Terms defined in the Credit Agreement are used herein as therein
defined.

         This Extension Agreement shall be construed in accordance with and
governed by the law of the State of New York.

                                            [BANKS]


                                            By
                                                --------------------------------
                                                Name:
                                                Title:

<PAGE>   57

Agreed and accepted:


NORTEL NETWORKS CORPORATION


By
   --------------------------------
   Name:
   Title:


By
   --------------------------------
   Name:
   Title:


J.P. MORGAN CANADA, as Administrative Agent


By
   --------------------------------
   Name:
   Title: