A/B EXCHANGE

                          REGISTRATION RIGHTS AGREEMENT


                           Dated as of April 26, 2000
                                  by and among


                                360networks inc.

               Donaldson, Lufkin & Jenrette Securities Corporation

                              Goldman, Sachs & Co.

                            Bear, Stearns & Co. Inc.

                              Chase Securities Inc.

                     Credit Suisse First Boston Corporation

                        Morgan Stanley & Co. Incorporated

                            Salomon Smith Barney Inc.

                       RBC Dominion Securities Corporation

                            TD Securities (USA) Inc.


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     This Registration Rights Agreement (this "Agreement") is made and entered
into as of April 26, 2000, by and among 360networks inc., a corporation
continued under the laws of Nova Scotia, Canada (the "Company") and Donaldson,
Lufkin & Jenrette Securities Corporation, Goldman, Sachs & Co., Bear, Sterns &
Co. Inc., Chase Securities Inc., Credit Suisse First Boston Corporation, Morgan
Stanley & Co. Incorporated, Salomon Smith Barney Inc., RBC Dominion Securities
Corporation and TD Securities (USA) Inc. (each, an "Initial Purchaser" and,
together, the "Initial Purchasers"), each of whom has agreed to purchase the
Company's US$ 13% Series A Senior Notes due 2008 (the "Series A Dollar Notes"),
pursuant to the Purchase Agreement (as defined below).

     This Agreement is made pursuant to the Purchase Agreement, dated April 20,
2000 (the "Purchase Agreement"), by and among the Company and the Initial
Purchasers. In order to induce the Initial Purchasers to purchase the Series A
Dollar Notes, the Company has agreed to provide the registration rights set
forth in this Agreement. The execution and delivery of this Agreement is a
condition to the obligations of the Initial Purchasers set forth in Section 3 of
the Purchase Agreement. Capitalized terms used herein and not otherwise defined
shall have the meaning assigned to them in the Indenture, dated April 26, 2000,
between the Company and HSBC Bank USA, as Trustee, relating to the Series A
Dollar Notes and the Series B Dollar Notes (the "Indenture").

     The parties hereby agree as follows:

1    DEFINITIONS

     As used in this Agreement, the following capitalized terms shall have the
following meanings:

     Act: The Securities Act of 1933, as amended.

     Affiliate: As defined in Rule 144 of the Act.

     Affiliated Market Maker: A Broker-Dealer who is deemed to be an Affiliate
of the Company.

     Broker-Dealer: Any broker or dealer registered under the Exchange Act.

     Business Day: Any day except a Saturday, Sunday or other day on which banks
are authorized to close in (a) the City of New York or (b) the city of the
corporate trust office of the Trustee.

     Certificated Securities: Definitive Notes, as defined in the Indenture.

     Closing Date: The date hereof.

     Commission: The Securities and Exchange Commission.


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     Consummate: An Exchange Offer shall be deemed "Consummated" for purposes of
this Agreement upon the occurrence of (a) the filing and effectiveness under the
Act of the Exchange Offer Registration Statement relating to the Series B Dollar
Notes to be issued in the Exchange Offer as evidence of the same underlying
indebtedness as the Series A Dollar Notes, (b) the maintenance of such Exchange
Offer Registration Statement continuously effective and the keeping of the
Exchange Offer open for a period not less than the period required pursuant to
Section 3(b) hereof and (c) the delivery by the Company to the Registrar under
the Indenture of Series B Dollar Notes in the same aggregate principal amount,
and as evidence of the same underlying indebtedness, as the aggregate principal
amount of Series A Dollar Notes tendered by Holders thereof pursuant to the
Exchange Offer.

     Consummation Deadline: As defined in Section 3(b) hereof.

     Effectiveness Deadline: As defined in Sections 3(a) and 4(a) hereof.

     Exchange Act: The Securities Exchange Act of 1934, as amended.

     Exchange Offer: The exchange and issuance by the Company of a principal
amount of Series B Dollar Notes (which shall be registered pursuant to the
Exchange Offer Registration Statement) equal to the outstanding principal amount
of Series A Dollar Notes, and as evidence of the same underlying indebtedness,
that are tendered by such Holders in connection with such exchange and issuance.

     Exchange Offer Registration Statement: The Registration Statement relating
to the Exchange Offer, including the related Prospectus.

     Exempt Resales: The transactions in which the Initial Purchasers propose to
sell the Series A Dollar Notes to certain "qualified institutional buyers," as
such term is defined in Rule 144A under the Act, and pursuant to Regulation S
under the Act.

     Filing Deadline: As defined in Sections 3(a) and 4(a) hereof.

     Holders: As defined in Section 2 hereof.

     Person: An individual, partnership, corporation, trust, unincorporated
organization or a government or agency or political subdivision thereof.

     Predecessor Division: The telecommunications division of Ledcor Inc.

     Prospectus: The prospectus included in a Registration Statement at the time
such Registration Statement is declared effective, as amended or supplemented by
any prospectus supplement and by all other amendments thereto, including
post-effective amendments, and all material incorporated by reference into such
Prospectus.

     Recommencement Date: As defined in Section 6(d) hereof.

     Registration Default: As defined in Section 5 hereof.



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     Registration Statement: Any registration statement of the Company relating
to (a) an offering of Series B Dollar Notes pursuant to an Exchange Offer or (b)
the registration for resale of Transfer Restricted Securities pursuant to the
Shelf Registration Statement, in each case, (i) that is filed pursuant to the
provisions of this Agreement and (ii) including the Prospectus included therein,
all amendments and supplements thereto (including post-effective amendments) and
all exhibits and material incorporated by reference therein.

     Regulation S: Regulation S promulgated under the Act.

     Rule 144: Rule 144 promulgated under the Act.

     Series B Dollar Notes: The Company's US$ 13% Series B Senior Notes due 2008
containing terms identical in all material respects to the Series A Dollar
Notes, and evidencing the same underlying indebtedness thereof, (except that (a)
interest thereon shall accrue from the last date on which interest was paid on
the Series A Dollar Notes or, if no such interest has been paid, from the date
of their original issue and (b) the transfer restrictions thereon shall be
eliminated to be issued pursuant to the Indenture: (i) in the Exchange Offer or
(ii) as contemplated by Section 4 hereof.

     Shelf Registration Statement: As defined in Section 4 hereof.

     Suspension Notice: As defined in Section 6(d) hereof.

     TIA: The Trust Indenture Act of 1939 (15 U.S.C. Section 77aaa-77bbbb) as in
effect on the date of the Indenture.

     Transfer Restricted Securities: Each (A) Series A Dollar Note, until the
earliest to occur of (i) the date on which such Series A Dollar Note is
exchanged in the Exchange Offer for a Series B Dollar Note, representing the
same underlying indebtedness as the Series A Dollar Note which is entitled to be
resold to the public by the Holder thereof without complying with the prospectus
delivery requirements of the Act, (ii) the date on which such Series A Dollar
Note has been disposed of in accordance with a Shelf Registration Statement (and
the purchasers thereof have been issued Series B Dollar Notes as evidence of the
same underlying indebtedness), (iii) the date on which such Series A Dollar Note
is disposed of by a Broker-Dealer pursuant to the "Plan of Distribution"
contemplated by the Exchange Offer Registration Statement (including the
delivery of the Prospectus contained therein) or (iv) the date on which such
Series A Dollar Note is distributed to the public pursuant to Rule 144 under the
Act.

2    HOLDERS

     A Person is deemed to be a holder of Transfer Restricted Securities (each,
a "Holder") whenever such Person owns Transfer Restricted Securities.

3    REGISTERED EXCHANGE OFFER

     (a) Unless the Exchange Offer shall not be permitted by applicable federal
law (after the procedures set forth in Section 6(a)(i) below have been complied
with), the Company shall (i) cause



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the Exchange Offer Registration Statement to be filed with the Commission as
soon as practicable after the Closing Date, but in no event later than 90 days
after the Closing Date (such 90th day being the "Filing Deadline"), (ii) use its
reasonable best efforts to cause such Exchange Offer Registration Statement to
become effective at the earliest possible time, but in no event later than 180
days after the Closing Date (such 180th day being the "Effectiveness Deadline"),
(iii) in connection with the foregoing, (A) file all pre-effective amendments to
such Exchange Offer Registration Statement as may be necessary in order to cause
it to become effective, (B) file, if applicable, a post-effective amendment to
such Exchange Offer Registration Statement pursuant to Rule 430A under the Act
and (C) cause all necessary filings, if any, in connection with the registration
and qualification of the Series B Dollar Notes to be made under the Blue Sky
laws of such jurisdictions as are necessary to permit Consummation of the
Exchange Offer, and (iv) upon the effectiveness of such Exchange Offer
Registration Statement, commence and Consummate the Exchange Offer. The Exchange
Offer shall be on the appropriate form permitting (i) registration of the Series
B Dollar Notes to be offered in exchange for the Series A Dollar Notes that are
Transfer Restricted Securities, as evidence of the same underlying indebtedness,
and (ii) resales of Series B Dollar Notes by Broker-Dealers that tendered into
the Exchange Offer Series A Dollar Notes that such Broker-Dealer acquired for
its own account as a result of market making activities or other trading
activities (other than Series A Dollar Notes acquired directly from the Company
or any of its Affiliates) as contemplated by Section 3(c) below.

     (b) The Company shall use its reasonable best efforts to cause the Exchange
Offer Registration Statement to be effective continuously, and shall keep the
Exchange Offer open for a period of not less than the minimum period required
under applicable federal and state securities laws to Consummate the Exchange
Offer; provided, however, that in no event shall such period be less than 20
Business Days. The Company shall cause the Exchange Offer to comply with all
applicable federal and state securities laws. No securities other than the
Series B Dollar Notes shall be included in the Exchange Offer Registration
Statement. The Company shall use its reasonable best efforts to cause the
Exchange Offer to be Consummated on the earliest practicable date after the
Exchange Offer Registration Statement has become effective, but in no event
later than 210 days after the Closing Date (such 210th day being the
"Consummation Deadline").

     (c) The Company shall include a "Plan of Distribution" section in the
Prospectus contained in the Exchange Offer Registration Statement and indicate
therein that any Broker-Dealer who holds Transfer Restricted Securities that
were acquired for the account of such Broker-Dealer as a result of market-making
activities or other trading activities (other than Series A Dollar Notes
acquired directly from the Company or any Affiliate of the Company), may
exchange such Transfer Restricted Securities pursuant to the Exchange Offer.
Such "Plan of Distribution" section shall also contain all other information
with respect to such sales by such Broker-Dealers that the Commission may
require in order to permit such sales pursuant thereto, but such "Plan of
Distribution" shall not name any such Broker-Dealer or disclose the amount of
Transfer Restricted Securities held by any such Broker-Dealer, except to the
extent required by the Commission as a result of a change in policy, rules or
regulations after the date of this Agreement.

     Because such Broker-Dealer may be deemed to be an "underwriter" within the
meaning of the Act and must, therefore, deliver a prospectus meeting the
requirements of the Act in connection with its initial sale of any Series B
Dollar Notes received by such Broker-Dealer in the Exchange



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<PAGE>

Offer, as evidence of the same underlying indebtedness as the Series A Dollar
Notes, the Company shall permit the use of the Prospectus contained in the
Exchange Offer Registration Statement by such Broker-Dealer to satisfy such
prospectus delivery requirement. To the extent necessary to ensure that the
prospectus contained in the Exchange Offer Registration Statement is available
for sales of Series B Dollar Notes by Broker-Dealers, the Company agrees to use
its reasonable best efforts to keep the Exchange Offer Registration Statement
continuously effective, supplemented, amended and current as required by and
subject to the provisions of Sections 6(a) and (c) hereof and in conformity with
the requirements of this Agreement, the Act and the policies, rules and
regulations of the Commission as announced from time to time, for a period of
one year (excluding any Exchange Offer Blackout Period (as defined)) from the
Consummation Deadline or such shorter period as will terminate when all Transfer
Restricted Securities covered by such Registration Statement have been sold
pursuant thereto; provided, further, that the Company may suspend the
effectiveness of the Exchange Offer Registration Statement, in the event that,
and for up to 2 periods of up to 30 consecutive days, but no more than an
aggregate of 45 consecutive days (an "Exchange Offer Blackout Period") if,
(a)(i) an event occurs and is continuing as a result of which the Exchange Offer
Registration Statement would, in the Company's good faith judgment, contain an
untrue statement of a material fact or omit to state a material fact necessary
in order to make the statements therein not misleading and (ii) if the Company
determines in good faith that the disclosure of such event at such time would
have a material adverse effect on the business operations or prospectus of the
Company or (b) the disclosure otherwise relates to a pending material business
transaction which has not yet been publicly disclosed; provided, further, that
the Company shall continue to pay Additional Interest, if any, during the
Exchange Offer Blackout Period. Upon the occurrence of any such suspension, the
Company will use its best efforts to reinstate effectiveness of such Exchange
Offer Registration Statement as soon as practicable. The Company shall provide
sufficient copies of the latest version of such Prospectus to such
Broker-Dealers, promptly upon request, and in no event later than one day after
such request, at any time during such period.

4    SHELF REGISTRATION

     (a) Shelf Registration. If (i) the Exchange Offer is not permitted by
applicable law or Commission Policy (after the Company has complied with the
procedures set forth in Section 6(a)(i) below) or (ii) if any Holder of Transfer
Restricted Securities shall notify the Company within 20 Business Days following
the consummation of the Exchange Offer that (A) such Holder was prohibited by
law or Commission policy from participating in the Exchange Offer or (B) such
Holder may not resell the Series B Dollar Notes acquired by it in the Exchange
Offer as evidence of the same underlying indebtedness as the Series A Dollar
Notes to the public without delivering a prospectus and the Prospectus contained
in the Exchange Offer Registration Statement is not appropriate or available for
such resales by such Holder or (C) such Holder is a Broker-Dealer and holds
Series A Dollar Notes acquired directly from the Company or any of its
Affiliates, then the Company shall:

     (x) cause to be filed, on or prior to 30 days after the earlier of (i) the
date on which the Company determines that the Exchange Offer Registration
Statement cannot be filed as a result of clause (a)(i) above and (ii) the date
on which the Company receives the notice specified in clause (a)(ii) above, (but
no earlier than 90 days after the Closing Date) (such earlier date, which shall
not



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be earlier than 90 days after the Closing Date, the "Filing Deadline"), a shelf
registration statement pursuant to Rule 415 under the Act (which may be an
amendment to the Exchange Offer Registration Statement (the "Shelf Registration
Statement")), relating to all Transfer Restricted Securities, and

     (y) shall use its reasonable best efforts to cause such Shelf Registration
Statement to become effective on or prior to 90 days after the Filing Deadline
for the Shelf Registration Statement (but no earlier than 210 days after the
Closing Date) (such day being the "Effectiveness Deadline").

     If, after the Company has filed an Exchange Offer Registration Statement
that satisfies the requirements of Section 3(a) above, the Company is required
to file and make effective a Shelf Registration Statement solely because the
Exchange Offer is not permitted under applicable federal law (i.e., clause
(a)(i) above), then the filing of the Exchange Offer Registration Statement
shall be deemed to satisfy the requirements of clause (x) above; provided that,
in such event, the Company shall remain obligated to meet the Effectiveness
Deadline set forth in clause (y).

     To the extent necessary to ensure that the Shelf Registration Statement is
available for sales of Transfer Restricted Securities by the Holders thereof
entitled to the benefit of this Section 4(a) and the other securities required
to be registered therein pursuant to Section 6(b)(ii) hereof, the Company shall
use its reasonable best efforts to keep any Shelf Registration Statement
required by this Section 4(a) continuously effective, supplemented, amended and
current as required by and subject to the provisions of Sections 6(b) and (c)
hereof and in conformity with the requirements of this Agreement, the Act and
the policies, rules and regulations of the Commission as announced from time to
time, for as long as any Initial Purchaser is deemed to be an Affiliate of the
Company, but in no event less than the shorter of (i) two years (excluding any
Shelf Blackout period (as defined)) (as extended pursuant to Section 6(d))
following the Closing Date or (ii) the date on which all Transfer Restricted
Securities covered by such Shelf Registration Statement have been sold pursuant
thereto; provided, further, that the Company may suspend the effectiveness of a
Shelf Registration Statement, in the event that, and for up to three periods of
up to 45 consecutive days, but no more than an aggregate of 90 days during any
365 day period (a "Shelf Blackout Period") if, (a)(i) an event occurs and is
continuing as a result of which the Shelf Registration Statement would, in the
Company's good faith judgment, contain an untrue statement of a material fact or
omit to state a material fact necessary in order to make the statements therein
not misleading and (ii) if the Company determines in good faith that the
disclosure of such event at such time would have a material adverse effect on
the business, operations or prospects of the Company or (b) the disclosure
otherwise relates to a pending material business transaction which has not yet
been publicly disclosed; provided, however, that the Company shall not pay
Additional Interest, during any such Shelf Blackout Period. Upon the occurrence
of any such suspension, the Company will use its reasonable best efforts to
reinstate effectiveness of such Shelf Registration Statement as soon as
practicable.

     (b) Provision by Holders of Certain Information in Connection with the
Shelf Registration Statement. No Holder of Transfer Restricted Securities may
include any of its Transfer Restricted Securities in any Shelf Registration
Statement pursuant to this Agreement unless and until such Holder furnishes to
the Company in writing, within 20 days after receipt of a request therefor, the
information specified in Item 507 or 508 of Regulation S-K, as applicable, of
the Act



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for use in connection with any Shelf Registration Statement or Prospectus or
preliminary Prospectus included therein. No Holder of Transfer Restricted
Securities shall be entitled to additional interest pursuant to Section 5 hereof
unless and until such Holder shall have provided all such information. Each
selling Holder agrees to promptly furnish additional information required to be
disclosed in order to make the information previously furnished to the Company
by such Holder not materially misleading.

5    additional interest

     If (i) any Registration Statement required by this Agreement is not filed
with the Commission on or prior to the applicable Filing Deadline, (ii) any such
Registration Statement has not been declared effective by the Commission on or
prior to the applicable Effectiveness Deadline, (iii) the Exchange Offer has not
been Consummated on or prior to the Consummation Deadline or (iv) any
Registration Statement required by this Agreement is filed and declared
effective but shall thereafter cease to be effective or fail to be usable for
its intended purpose without being succeeded within two days by a post-effective
amendment to such Registration Statement that cures such failure and that is
itself declared effective (within five days of filing such post-effective
amendment to such Registration Statement) (each such event referred to in
clauses (i) through (iv), a "Registration Default"), then the Company hereby
agrees to pay to each Holder of Transfer Restricted Securities affected thereby
additional interest ("Additional Interest") which will accrue and be payable at
the time interest is due on the Series A Dollar Notes and the Series B Dollar
Notes (in addition to the stated interest on the Series A Dollar Notes and the
Series B Dollar Notes) from and including the date such Registration Default
occurs to, but not including, the date on which the applicable Registration
Statement is filed or is declared effective, the Exchange Offer is consummated,
or the applicable Registration Statement is again declared effective or made
usable. During the time that Additional Interest is accruing continuously, the
rate of such Additional Interest shall be 0.50% per annum during the first
90-day period and shall increase by 0.25% per annum for each subsequent 90-day
period, but in no event shall such rate exceed 1.50% per annum in the aggregate
regardless of the number of Registration Defaults. If, after the cure of all
Registration Defaults then in effect, there is a subsequent Registration
Default, the rate of Additional Interest for such subsequent Registration
Default shall initially be 0.50%, regardless of the Additional Interest rate in
effect with respect to any prior Registration Default at the time of the cure of
such Registration Default.

     All accrued Additional Interest shall be paid by the Company to the Holders
entitled thereto in the same manner and on the same date as interest payments on
the Notes, as more fully described in the Indenture. Notwithstanding the fact
that any securities for which Additional Interest are due cease to be Transfer
Restricted Securities, all obligations of the Company to pay Additional Interest
with respect thereto shall survive until such time as such obligations with
respect to such securities shall have been satisfied in full.

6    REGISTRATION PROCEDURES

     (a) Exchange Offer Registration Statement. In connection with the Exchange
Offer, the Company shall (x) comply with all applicable provisions of Section
6(c) below, (y) use its reasonable best efforts to effect such exchange and to
permit the resale of Series B Dollar Notes by



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Broker-Dealers that tendered in the Exchange Offer Series A Dollar Notes that
such Broker-Dealer acquired for its own account as a result of its market making
activities or other trading activities (other than Series A Dollar Notes
acquired directly from the Company or any of its Affiliates) being sold in
accordance with the intended method or methods of distribution thereof, and (z)
comply with all of the following provisions:

          (i) If, following the date hereof there has been announced a change in
     Commission policy with respect to exchange offers such as the Exchange
     Offer, that in the reasonable opinion of counsel to the Company raises a
     substantial question as to whether the Exchange Offer is permitted by
     applicable federal law, the Company hereby agrees to seek a no-action
     letter or other favorable decision from the Commission allowing the Company
     to Consummate an Exchange Offer for such Transfer Restricted Securities
     (unless in the reasonable opinion of counsel to the Company, the filing of
     such no-action letter is not appropriate). The Company hereby agrees to
     pursue the issuance of such a decision to the Commission staff level. In
     connection with the foregoing, the Company hereby agrees to take all such
     other actions as may be requested by the Commission or otherwise required
     in connection with the issuance of such decision.

          (ii) As a condition to its participation in the Exchange Offer, each
     Holder of Transfer Restricted Securities (including, without limitation,
     any Holder who is a Broker-Dealer) shall furnish, upon the request of the
     Company, prior to the Consummation of the Exchange Offer, a written
     representation to the Company (which may be contained in the letter of
     transmittal contemplated by the Exchange Offer Registration Statement) to
     the effect that (A) it is not an Affiliate of the Company, (B) it is not
     engaged in, and does not intend to engage in, and has no arrangement or
     understanding with any person to participate in, a distribution of the
     Series B Dollar Notes to be issued in the Exchange Offer and (C) it is
     acquiring the Series B Dollar Notes in its ordinary course of business. As
     a condition to its participation in the Exchange Offer each Holder using
     the Exchange Offer to participate in a distribution of the Series B Dollar
     Notes shall acknowledge and agree that, if the resales are of Series B
     Dollar Notes obtained by such Holder in exchange for, and as evidence of
     the same underlying indebtedness as, Series A Dollar Notes acquired
     directly from the Company or an Affiliate thereof, it (1) could not, under
     Commission policy as in effect on the date of this Agreement, rely on the
     position of the Commission enunciated in Morgan Stanley and Co., Inc.
     (available June 5, 1991) and Exxon Capital Holdings Corporation (available
     May 13, 1988), as interpreted in the Commission's letter to Shearman &
     Sterling dated July 2, 1993, and similar no-action letters (including, if
     applicable, any no-action letter obtained pursuant to clause (i) above),
     and (2) must comply with the registration and prospectus delivery
     requirements of the Act in connection with a secondary resale transaction
     and that such a secondary resale transaction must be covered by an
     effective registration statement containing the selling security holder
     information required by Item 507 or 508, as applicable, of Regulation S-K.



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<PAGE>

          (iii) Prior to effectiveness of the Exchange Offer Registration
     Statement, the Company shall provide a supplemental letter to the
     Commission (A) stating that the Company is registering the Exchange Offer
     in reliance on the position of the Commission enunciated in Exxon Capital
     Holdings Corporation (available May 13, 1988), Morgan Stanley and Co., Inc.
     (available June 5, 1991) as interpreted in the Commission's letter to
     Shearman & Sterling dated July 2, 1993, and, if applicable, any no-action
     letter obtained pursuant to clause (i) above, (B) including a
     representation that the Company has not entered into any arrangement or
     understanding with any Person to distribute the Series B Dollar Notes to be
     received in the Exchange Offer and that, to the best of the Company's
     information and belief, each Holder participating in the Exchange Offer is
     acquiring the Series B Dollar Notes in its ordinary course of business and
     has no arrangement or understanding with any Person to participate in the
     distribution of the Series B Dollar Notes received in the Exchange Offer
     and (C) any other undertaking or representation required by the Commission
     as set forth in any no-action letter obtained pursuant to clause (i) above,
     if applicable.

     (b) Shelf Registration Statement. In connection with the Shelf Registration
Statement, the Company shall:

          (ii) comply with all the provisions of Section 6(c) below and use its
     reasonable best efforts to effect such registration to permit the sale of
     the Transfer Restricted Securities being sold in accordance with the
     intended method or methods of distribution thereof (as indicated in the
     information furnished to the Company pursuant to Section 4(b) hereof), and
     pursuant thereto the Company will prepare and file with the Commission a
     Registration Statement relating to the registration on any appropriate form
     under the Act, which form shall be available for the sale of the Transfer
     Restricted Securities in accordance with the intended method or methods of
     distribution thereof within the time periods and otherwise in accordance
     with the provisions hereof, and

          (iii) issue, upon the request of any Holder or purchaser of Series A
     Dollar Notes covered by any Shelf Registration Statement contemplated by
     this Agreement, Series B Dollar Notes having an aggregate principal amount
     equal to, and representing the same underlying indebtedness as, the
     aggregate principal amount of Series A Dollar Notes sold pursuant to the
     Shelf Registration Statement and surrendered to the Company for
     cancellation; the Company shall register Series B Dollar Notes on the Shelf
     Registration Statement for this purpose and issue the Series B Dollar Notes
     to the purchasers of securities subject to the Shelf Registration Statement
     in the names as such purchasers shall designate.

     (c) General Provisions. In connection with any Registration Statement and
any related Prospectus required by this Agreement, the Company shall:



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<PAGE>

          (i) use its reasonable best efforts to keep such Registration
     Statement continuously effective and provide all requisite financial
     statements for the period specified in Section 3 or 4 of this Agreement, as
     applicable. Upon the occurrence of any event that would cause any such
     Registration Statement or the Prospectus contained therein (A) to contain
     an untrue statement of material fact or omit to state any material fact
     necessary to make the statements therein not misleading or (B) not to be
     effective and usable for resale of Transfer Restricted Securities during
     the period required by this Agreement, the Company shall file promptly an
     appropriate amendment to such Registration Statement curing such defect,
     and, if Commission review is required, use its reasonable best efforts to
     cause such amendment to be declared effective as soon as practicable.

          (ii) prepare and file with the Commission such amendments and
     post-effective amendments to the applicable Registration Statement as may
     be necessary to keep such Registration Statement effective for the
     applicable period set forth in Section 3 or 4 hereof, as the case may be;
     cause the Prospectus to be supplemented by any required Prospectus
     supplement, and as so supplemented to be filed pursuant to Rule 424 under
     the Act, and to comply fully with Rules 424, 430A and 462, as applicable,
     under the Act in a timely manner; and comply with the provisions of the Act
     with respect to the disposition of all securities covered by such
     Registration Statement during the applicable period in accordance with the
     intended method or methods of distribution by the sellers thereof set forth
     in such Registration Statement or supplement to the Prospectus;

          (iii) advise each selling Holder and each Initial Purchaser who is
     required to deliver a prospectus in connection with sales or market making
     activities ( an "Affiliated Market Maker") promptly and, if requested by
     such Person, confirm such advice in writing, (A) when the Prospectus or any
     Prospectus supplement or post-effective amendment has been filed, and, with
     respect to any applicable Registration Statement or any post-effective
     amendment thereto, when the same has become effective, (B) of any request
     by the Commission for amendments to the Registration Statement or
     amendments or supplements to the Prospectus or for additional information
     relating thereto, (C) of the issuance by the Commission of any stop order
     suspending the effectiveness of the Registration Statement under the Act or
     of the suspension by any state securities commission of the qualification
     of the Transfer Restricted Securities for offering or sale in any
     jurisdiction, or the initiation of any proceeding for any of the preceding
     purposes, and (D) of the existence of any fact or the happening of any
     event that makes any statement of a material fact made in the Registration
     Statement, the Prospectus, any amendment or supplement thereto or any
     document incorporated by reference therein untrue, or that requires the
     making of any additions to or changes in the Registration Statement in
     order to make the statements therein not misleading, or that requires the
     making of any additions to or changes in the Prospectus in order to make
     the statements therein, in the light of the circumstances under which they
     were made, not misleading. If at any time the Commission shall issue any
     stop order suspending the effectiveness of the Registration Statement, or
     any state securities commission or



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<PAGE>

     other regulatory authority shall issue an order suspending the
     qualification or exemption from qualification of the Transfer Restricted
     Securities under state securities or Blue Sky laws, the Company shall use
     its reasonable best efforts to obtain the withdrawal or lifting of such
     order at the earliest possible time;

          (iv) subject to Section 6(c)(i), if any fact or event contemplated by
     Section 6(c)(iii)(D) above shall exist or have occurred, prepare a
     supplement or post-effective amendment to the Registration Statement or
     related Prospectus or any document incorporated therein by reference or
     file any other required document so that, as thereafter delivered to the
     purchasers of Transfer Restricted Securities, the Prospectus will not
     contain an untrue statement of a material fact or omit to state any
     material fact necessary to make the statements therein, in the light of the
     circumstances under which they were made, not misleading;

          (v) furnish to each selling Holder and each Affiliated Market Maker,
     in connection with such sale, if any, before filing with the Commission,
     copies of any Registration Statement or any Prospectus included therein or
     any amendments or supplements to any such Registration Statement or
     Prospectus (including all documents incorporated by reference after the
     initial filing of such Registration Statement), which documents will be
     subject to the review and comment of such Persons in connection with such
     sale, if any, for a period of at least five Business Days, and the Company
     will not file any such Registration Statement or Prospectus or any
     amendment or supplement to any such Registration Statement or Prospectus
     (including all such documents incorporated by reference) to which such
     Persons shall reasonably object within five Business Days after the receipt
     thereof. Such Person shall be deemed to have reasonably objected to such
     filing if such Registration Statement, amendment, Prospectus or supplement,
     as applicable, as proposed to be filed, contains an untrue statement of a
     material fact or omit to state any material fact necessary to make the
     statements therein not misleading or fails to comply with the applicable
     requirements of the Act;

          (vi) promptly prior to the filing of any document that is to be
     incorporated by reference into a Registration Statement or Prospectus,
     provide copies of such document to each selling Holder and each Affiliated
     Market Maker in connection with such sale, if any, make the Company's
     representatives available for discussion of such document and other
     customary due diligence matters, and include such information in such
     document prior to the filing thereof as such Persons may reasonably
     request; provided, however, that such Persons shall first agree in writing
     with the Company that any information that is reasonably and in good faith
     designated by the Company in writing as confidential at the time of
     delivery of such information shall be kept confidential by such Persons,
     unless (a) disclosure of such information is required by court or
     administrative order or is necessary to respond to inquiries of regulatory
     authorities, (b) disclosure of such information is required by law
     (including any disclosure requirements pursuant to federal securities laws
     in connection with the filing of such Registration Statement or the use of
     such Prospectus), (c) such information becomes generally available to



                                       11
<PAGE>

     the public other than as a result of a disclosure or failure to safeguard
     such information by such Person or (d) such information becomes available
     to such Persons from a source other than the Company and its subsidiaries
     and such source is not known, after due inquiry, by such Person to be bound
     by a confidentiality agreement; provided, further, that the foregoing
     investigation shall be coordinated on behalf of such Persons by one
     representative designated by and on behalf of such Persons and any such
     confidential information shall be available from such representative to
     such Persons so long as any Person agrees to be bound by such
     confidentiality agreement;

          (vii) make available, at reasonable times, for inspection by each
     selling Holder and each Affiliated Market Maker and any attorney or
     accountant retained by such Persons, all financial and other records,
     pertinent corporate documents of the Company and cause the Company's
     officers, directors and employees to supply all information reasonably
     requested in writing by any such Person, attorney or accountant in
     connection with such Registration Statement or any post-effective amendment
     thereto subsequent to the filing thereof and prior to its effectiveness;

          (viii) if requested by any selling Holders in connection with such
     sale or any Affiliated Market Maker, promptly include in any Registration
     Statement or Prospectus, pursuant to a supplement or post-effective
     amendment if necessary, such information as such Persons may reasonably
     request in writing to have included therein, including, without limitation,
     information relating to the "Plan of Distribution" of the Transfer
     Restricted Securities, and make all required filings of such Prospectus
     supplement or post-effective amendment as soon as practicable after the
     Company is notified of the matters to be included in such Prospectus
     supplement or post-effective amendment;

          (ix) furnish to each selling Holder in connection with such sale and
     each Affiliated Market Maker, without charge, at least one copy of the
     Registration Statement, as first filed with the Commission, and of each
     amendment thereto, including all documents incorporated by reference
     therein and all exhibits (including exhibits incorporated therein by
     reference);

          (x) deliver to each selling Holder and each Affiliated Market Maker,
     without charge, as many copies of the Prospectus (including each
     preliminary prospectus) and any amendment or supplement thereto as such
     Persons reasonably may request; the Company hereby consents to the use (in
     accordance with law) of the Prospectus and any amendment or supplement
     thereto by each Person in connection with the offering and the sale of the
     Transfer Restricted Securities covered by the Prospectus or any amendment
     or supplement thereto and all market making activities of such Affiliated
     Market Maker, as the case may be;

          (xi) upon the request of any Holder, enter into such agreements
     (including underwriting agreements) and make such representations and
     warranties and take all such other actions in connection therewith in order
     to expedite or



                                       12
<PAGE>

     facilitate the disposition of the Transfer Restricted Securities pursuant
     to any applicable Registration Statement contemplated by this Agreement as
     may be reasonably requested in writing by any Holder in connection with any
     sale or resale pursuant to any applicable Registration Statement. In such
     connection, and also in connection with market making activities by any
     Affiliated Market Maker, the Company shall:

               (A) upon written request of any selling Holder or any Affiliated
          Market Maker, furnish (or in the case of paragraphs (2) and (3), use
          its reasonable best efforts to cause to be furnished) to each Person,
          upon Consummation of the Exchange Offer or upon the effectiveness of
          the Shelf Registration Statement, as the case may be:

                    (1) a certificate, dated such date, signed on behalf of the
               Company by (x) the President or any Vice President and (y) a
               principal financial or accounting officer of the Company,
               confirming, as of the date thereof, the matters set forth in
               Sections 6(z), 9(a) and 9(b) of the Purchase Agreement and such
               other similar matters as such Persons may reasonably request;

                    (2) an opinion, dated the date of Consummation of the
               Exchange Offer or the date of effectiveness of the Shelf
               Registration Statement, as the case may be, of counsel for the
               Company covering matters similar to those set forth in Section
               9(e) of the Purchase Agreement and such other matters as such
               Holder may reasonably request, and including, without limitation,
               the paragraph relating to Section 10b-5 under the Exchange Act;
               and

                    (3) On the date of Consummation of the Exchange Offer or the
               date of effectiveness of the Shelf Registration Statement, as
               applicable, customary comfort letters, dated the date of
               Consummation of the Exchange Offer, or as of the date of
               effectiveness of the Shelf Registration Statement, as the case
               may be, from the independent accountants of the Company and the
               Predecessor Division, in the customary form and covering matters
               of the type customarily covered in comfort letters to
               underwriters in connection with underwritten offerings, and
               affirming the matters set forth in the comfort letters delivered
               pursuant to Section 9(j) of the Purchase Agreement; and

               (B) deliver such other documents and certificates as may be
          reasonably requested in writing by the such Persons to evidence
          compliance with the matters covered in clause (A) above and with any
          customary conditions contained in any agreement entered into by the
          Company pursuant to this clause (xi);

          (xii) prior to any public offering of Transfer Restricted Securities,
     cooperate with the selling Holders and their counsel in connection with the
     registration and qualification of the Transfer Restricted Securities under
     the securities or Blue Sky laws of such jurisdictions as the selling
     Holders may



                                       13
<PAGE>

     reasonably request in writing and do any and all other acts or things
     necessary or advisable to enable the disposition in such jurisdictions of
     the Transfer Restricted Securities covered by the applicable Registration
     Statement; provided, however, that the Company shall not be required to
     register or qualify as a foreign corporation where it is not now so
     qualified or to take any action that would subject it to the service of
     process in suits or to taxation, other than as to matters and transactions
     relating to the Registration Statement, in any jurisdiction where it is not
     now so subject;

          (xiii) in connection with any sale of Transfer Restricted Securities
     that will result in such securities no longer being Transfer Restricted
     Securities, cooperate with the Holders to facilitate the timely preparation
     and delivery of certificates representing Transfer Restricted Securities to
     be sold and not bearing any restrictive legends; and to register such
     Transfer Restricted Securities in such denominations and such names as the
     selling Holders may request in writing at least two Business Days prior to
     such sale of Transfer Restricted Securities;

          (xiv) use its reasonable best efforts to cause the disposition of the
     Transfer Restricted Securities covered by the Registration Statement to be
     registered with or approved by such other governmental agencies or
     authorities as may be necessary to enable the seller or sellers thereof to
     consummate the disposition of such Transfer Restricted Securities, subject
     to the proviso contained in clause (xii) above;

          (xv) provide a CUSIP number for all Transfer Restricted Securities not
     later than the effective date of a Registration Statement covering such
     Transfer Restricted Securities and provide the Trustee under the Indenture
     with printed certificates for the Transfer Restricted Securities which are
     in a form eligible for deposit with the Depository Trust Company;

          (xvi) otherwise use its best efforts to comply with all applicable
     rules and regulations of the Commission, and make generally available to
     its security holders with regard to any applicable Registration Statement,
     as soon as practicable, a consolidated earnings statement meeting the
     requirements of Rule 158 (which need not be audited) covering a
     twelve-month period beginning after the effective date of the Registration
     Statement (as such term is defined in paragraph (c) of Rule 158 under the
     Act);

          (xvii) cause the Indenture to be qualified under the TIA not later
     than the effective date of the first Registration Statement required by
     this Agreement and, in connection therewith, cooperate with the Trustee and
     the Holders to effect such changes to the Indenture as may be required for
     such Indenture to be so qualified in accordance with the terms of the TIA;
     and execute and use its best efforts to cause the Trustee to execute, all
     documents that may be required to effect such changes and all other forms
     and documents required to be filed with the Commission to enable such
     Indenture to be so qualified in a timely manner; and



                                       14
<PAGE>

          (xviii) provide promptly to each Holder and each Affiliated Market
     Maker, upon request, each document filed with the Commission pursuant to
     the requirements of Section 13 or Section 15(d) of the Exchange Act, unless
     already provided.

     (d) Restrictions on Holders. Each Holder and each Affiliated Market Maker
agrees by acquisition of a Transfer Restricted Security that, upon receipt of
the notice referred to in Section 6(c)(iii)(C) or any notice from the Company of
the existence of any fact of the kind described in Section 6(c)(iii)(D) hereof
(in each case, a "Suspension Notice"), such Person will forthwith discontinue
disposition of Transfer Restricted Securities pursuant to the applicable
Registration Statement until (i) such Person has received copies of the
supplemented or amended Prospectus contemplated by Section 6(c)(iv) hereof, or
(ii) such Person is advised in writing by the Company that the use of the
Prospectus may be resumed, and has received copies of any additional or
supplemental filings that are incorporated by reference in the Prospectus (in
each case, the "Recommencement Date"). Each Person receiving a Suspension Notice
hereby agrees that it will either (i) destroy any Prospectuses, other than
permanent file copies, then in such Person's possession which have been replaced
by the Company with more recently dated Prospectuses or (ii) deliver to the
Company (at the Company's expense) all copies, other than permanent file copies,
then in such Person's possession of the Prospectus covering such Transfer
Restricted Securities that was current at the time of receipt of the Suspension
Notice. The time period regarding the effectiveness of such Registration
Statement set forth in Section 3 or 4 hereof, as applicable, shall be extended
by a number of days equal to the number of days in the period from and including
the date of delivery of the Suspension Notice to the date of delivery of the
Recommencement Date.

7    REGISTRATION EXPENSES

     (a) All expenses incident to the Company's performance of or compliance
with this Agreement will be borne by the Company, regardless of whether a
Registration Statement becomes effective, including without limitation: (i) all
registration and filing fees and expenses; (ii) all fees and expenses of
compliance with federal securities and Blue Sky or securities laws of any states
or relevant foreign jurisdictions; (iii) all expenses of printing (including
printing certificates for the Series B Dollar Notes to be issued in the Exchange
Offer, as evidence of the same underlying indebtedness as the Series A Dollar
Notes, and printing of Prospectuses whether for exchanges, sales, market making
or otherwise), messenger and delivery services and telephone; (iv) all fees and
disbursements of counsel for the Company; (v) all application and filing fees in
connection with listing the Series B Dollar Notes on a national securities
exchange or automated quotation system pursuant to the requirements hereof; and
(vi) all fees and disbursements of independent certified public accountants of
the Company and the Predecessor Division (including the expenses of any special
audit and comfort letters required by or incident to such performance).

     The Company will, in any event, bear its internal expenses (including,
without limitation, all salaries and expenses of its officers and employees
performing legal or accounting duties), the expenses of any annual audit and the
fees and expenses of any Person, including special experts, retained by the
Company.



                                       15
<PAGE>

     Each Holder shall pay all underwriting discounts and commissions and
transfer taxes, if any, relating to the sale or disposition of such Holder's
Transfer Restricted Securities.

     (b) In connection with any Registration Statement required by this
Agreement (including, without limitation, the Exchange Offer Registration
Statement and the Shelf Registration Statement), the Company will reimburse the
Initial Purchasers and the Holders of Transfer Restricted Securities who are
tendering Series A Dollar Notes in the Exchange Offer and/or selling or
reselling Series A Dollar Notes or Series B Dollar Notes pursuant to the "Plan
of Distribution" contained in the Exchange Offer Registration Statement or the
Shelf Registration Statement, as applicable, for the reasonable fees and
disbursements of not more than one counsel with respect to matters of U.S. law
and one counsel with respect to matters of Canadian law, who shall be Latham &
Watkins and Osler, Hoskin & Harcourt LLP, respectively, unless another firm
shall be chosen by the Holders of a majority in principal amount of the Transfer
Restricted Securities for whose benefit such Registration Statement is being
prepared.

8    INDEMNIFICATION

     (a) The Company agrees to indemnify and hold harmless each Holder, its
directors, officers and each Person, if any, who controls such Holder (within
the meaning of Section 15 of the Act or Section 20 of the Exchange Act), from
and against any and all losses, claims, damages, liabilities, judgments,
(including without limitation, any legal or other expenses incurred in
connection with investigating or defending any matter, including any action that
could give rise to any such losses, claims, damages, liabilities or judgments)
caused by any untrue statement or alleged untrue statement of a material fact
contained in any Registration Statement, preliminary prospectus or Prospectus
(or any amendment or supplement thereto) provided by the Company to any Holder
or any prospective purchaser of Series B Dollar Notes or registered Series A
Dollar Notes, or caused by any omission or alleged omission to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, except insofar as such losses, claims, damages,
liabilities or judgments are caused by an untrue statement or omission or
alleged untrue statement or omission that is based upon information relating to
any of the Holders furnished in writing to the Company by any of the Holders;
provided, however, that the foregoing indemnity agreement with respect to any
preliminary prospectus, shall not inure to the benefit of any such person who
failed to deliver a Prospectus (so long as the Prospectus was provided by the
Company to such person in the requisite quantity and on a timely basis to permit
proper delivery) to the person asserting any losses, claims, damages,
liabilities or judgments caused by any untrue statement or alleged untrue
statement of a material fact contained in the preliminary prospectus, or caused
by any omission or alleged omission to state therein a material fact required to
be stated therein or necessary to make the statements therein not misleading, if
such material misstatement or omission or alleged material misstatement or
omission was cured in the Prospectus.

     (b) Each Holder of Transfer Restricted Securities agrees, severally and not
jointly, to indemnify and hold harmless the Company, and its directors and
officers, and each person, if any, who controls (within the meaning of Section
15 of the Act or Section 20 of the Exchange Act) the Company, to the same extent
as the foregoing indemnity from the Company set forth in Section 8(a) above, but
only with reference to information relating to such Holder furnished in writing
to the Company by such Holder expressly for use in any Registration Statement.
In no event shall any



                                       16
<PAGE>

Holder, its directors, officers or any Person who controls such Holder be liable
or responsible for any amount in excess of the amount by which the total amount
received by such Holder with respect to its sale of Transfer Restricted
Securities pursuant to a Registration Statement exceeds (i) the amount paid by
such Holder for such Transfer Restricted Securities and (ii) the amount of any
damages that such Holder, its directors, officers or any Person who controls
such Holder has otherwise been required to pay by reason of such untrue or
alleged untrue statement or omission or alleged omission.

     (c) In case any action shall be commenced involving any person in respect
of which indemnity may be sought pursuant to Section 8(a) or 8(b) (the
"indemnified party"), the indemnified party shall promptly notify the person
against whom such indemnity may be sought (the "indemnifying person") in writing
and the indemnifying party shall assume the defense of such action, including
the employment of counsel reasonably satisfactory to the indemnified party and
the payment of all fees and expenses of such counsel, as incurred (except that
in the case of any action in respect of which indemnity may be sought pursuant
to both Sections 8(a) and 8(b), a Holder shall not be required to assume the
defense of such action pursuant to this Section 8(c), but may employ separate
counsel and participate in the defense thereof, but the fees and expenses of
such counsel, except as provided below, shall be at the expense of the Holder).
Any indemnified party shall have the right to employ separate counsel in any
such action and participate in the defense thereof, but the fees and expenses of
such counsel shall be at the expense of the indemnified party unless (i) the
employment of such counsel shall have been specifically authorized in writing by
the indemnifying party, (ii) the indemnifying party shall have failed to assume
the defense of such action or employ counsel reasonably satisfactory to the
indemnified party or (iii) the named parties to any such action (including any
impleaded parties) include both the indemnified party and the indemnifying
party, and the indemnified party shall have been advised by such counsel that
there may be one or more legal defenses available to it which are different from
or additional to those available to the indemnifying party (in which case the
indemnifying party shall not have the right to assume the defense of such action
on behalf of the indemnified party). In any such case, the indemnifying party
shall not, in connection with any one action or separate but substantially
similar or related actions in the same jurisdiction arising out of the same
general allegations or circumstances, be liable for the fees and expenses of
more than one separate firm of attorneys with respect to matters of U.S. law and
one separate firm of attorneys with respect to matters of Canadian law (in each
case, in addition to any local counsel) for all indemnified parties and all such
fees and expenses shall be reimbursed as they are incurred. Such firm shall be
designated in writing by a majority of the Holders, in the case of the parties
indemnified pursuant to Section 8(a), and by the Company, in the case of parties
indemnified pursuant to Section 8(b). The indemnifying party shall indemnify and
hold harmless the indemnified party from and against any and all losses, claims,
damages, liabilities and judgments by reason of any settlement of any action (i)
effected with its written consent or (ii) effected without its written consent
if the settlement is entered into more than twenty Business Days after the
indemnifying party shall have received a request from the indemnified party for
reimbursement for the fees and expenses of counsel (in any case where such fees
and expenses are at the expense of the indemnifying party) and, prior to the
date of such settlement, the indemnifying party shall have failed to comply with
such reimbursement request. No indemnifying party shall, without the prior
written consent of the indemnified party, effect any settlement or compromise
of, or consent to the entry of judgment



                                       17
<PAGE>

with respect to, any pending or threatened action in respect of which the
indemnified party is or could have been a party and indemnity or contribution
may be or could have been sought hereunder by the indemnified party, unless such
settlement, compromise or judgment (i) includes an unconditional release of the
indemnified party from all liability on claims that are or could have been the
subject matter of such action and (ii) does not include a statement as to or an
admission of fault, culpability or a failure to act, by or on behalf of the
indemnified party.

     (d) To the extent that the indemnification provided for in this Section 8
is unavailable to an indemnified party in respect of any losses, claims,
damages, liabilities or judgments referred to therein, then each indemnifying
party, in lieu of indemnifying such indemnified party, shall contribute to the
amount paid or payable by such indemnified party as a result of such losses,
claims, damages, liabilities or judgments (i) in such proportion as is
appropriate to reflect the relative benefits received by the Company, on the one
hand, and the Holders, on the other hand, from their sale of Transfer Restricted
Securities or (ii) if the allocation provided by clause 8(d)(i) is not permitted
by applicable law, in such proportion as is appropriate to reflect not only the
relative benefits referred to in clause 8(d)(i) above but also the relative
fault of the Company, on the one hand, and of the Holder, on the other hand, in
connection with the statements or omissions which resulted in such losses,
claims, damages, liabilities or judgments, as well as any other relevant
equitable considerations. The relative fault of the Company, on the one hand,
and of the Holder, on the other hand, shall be determined by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission or alleged omission to state a material fact relates to
information supplied by the Company, on the one hand, or by the Holder, on the
other hand, and the parties' relative intent, knowledge, access to information
and opportunity to correct or prevent such statement or omission. The amount
paid or payable by a party as a result of the losses, claims, damages,
liabilities and judgments referred to above shall be deemed to include, subject
to the limitations set forth in the second paragraph of Section 8(a), any legal
or other fees or expenses reasonably incurred by such party in connection with
investigating or defending any action or claim.

     The Company and each Holder agree that it would not be just and equitable
if contribution pursuant to this Section 8(d) were determined by pro rata
allocation (even if the Holders were treated as one entity for such purpose) or
by any other method of allocation which does not take account the equitable
considerations referred to in the immediately preceding paragraph. The amount
paid or payable by an indemnified party as a result of the losses, claims,
damages, liabilities or judgments referred to in the immediately preceding
paragraph shall be deemed to include, subject to the limitations set forth
above, any legal or other expenses reasonably incurred by such indemnified party
in connection with investigating or defending any matter, including any action
that could have given rise to such losses, claims, damages, liabilities or
judgments. Notwithstanding the provisions of this Section 8, no Holder, its
directors, its officers or any Person, if any, who controls such Holder shall be
required to contribute, in the aggregate, any amount in excess of the amount by
which the total received by such Holder with respect to the sale of its Transfer
Restricted Securities pursuant to a Registration Statement exceeds the sum of
(i) the amount paid by such Holder for such Transfer Restricted Securities and
(ii) the amount of any damages which such Holder has otherwise been required to
pay by reason of such untrue or alleged untrue statement or omission or alleged
omission. No person guilty of fraudulent misrepresentation (within the meaning
of Section 11(f) of the Act) shall be entitled to contribution from any person
who was not guilty of such fraudulent misrepresentation. The Holders'
obligations to contribute



                                       18
<PAGE>

pursuant to this Section 8(d) are several in proportion to the respective
principal amount of Transfer Restricted Securities held by each Holder hereunder
and not joint.

     (e) The Company agrees that the indemnity and contribution provisions of
this Section 8 shall apply to Affiliated Market Makers to the same extent, on
the same conditions, as it applies to Holders.

9    RULE 144A and RULE 144

     For so long as any Notes remain outstanding, the Company shall furnish to
the Holders the information required to be delivered pursuant to Rule 144A(d)(4)
under the Securities Act. Whether or not the Company is subject to Section 13(a)
or 15(d) of the Exchange Act, the Company shall file with the SEC and furnish to
the Holders and the Trustee (i) within 140 days after the end of each fiscal
year, annual reports on Form 20-F or 40-F, as applicable (or any successor
form), containing the information required to be contained therein (or required
in such successor form) and (ii) (a) within 45 days after the end of each of the
first three fiscal quarters of each fiscal year, reports on Form 10-Q or (b)
within 60 days after the end of each of the first three fiscal quarters of each
fiscal year, reports on Form 6-K (or any successor form) which, regardless of
applicable requirements, shall, at a minimum, contain a "Management's Discussion
and Analysis of Financial Condition and Results of Operations."

10   submission to jurisdiction; appointment of agent for service

     To the fullest extent permitted by applicable law, the Company irrevocably
submits to the jurisdiction of any federal or state court the Borough of
Manhattan in the City, County and State of New York, United States of America,
in any suit or proceeding based on or arising under this Agreement (solely in
connection with any such suit or proceeding), and irrevocably agrees that all
claims in respect of such suit or proceeding may be determined in any such
court. The Company irrevocably and fully waives the defense of an inconvenient
forum to the maintenance of such suit or proceeding. The Company agrees that
final judgment in any such suit, action or proceeding brought in such a court
shall be conclusive and binding upon the Company and may be enforced in the
courts of Canada (or any other courts to the jurisdiction of which the Company
is subject) by a suit upon such judgment, provided that service of process is
effected upon the Company in the manner specified herein. The Company hereby
irrevocably designates and appoints CT Corporation System (the "Process Agent"),
as the authorized agent of the Company upon whom process may be served in any
such suit or proceeding, it being understood that the designation and
appointment of CT Corporation System as such authorized agent shall become
effective immediately without any further action on the part of the Company. The
Company represents to the Initial Purchasers that it has notified the Process
Agent of such designation and appointment and that the Process Agent has
accepted the same in writing. The Company hereby irrevocably authorizes and
directs the Process Agent to accept such service. The Company further agrees
that, to the extent permitted by law, service of process upon the Process Agent
and written notice of said service to the Company mailed by prepaid registered
first class mail at its address specified in Section 12 of this Agreement, shall
be deemed in every respect effective service of process upon the Company in any
such suit or proceeding. Nothing herein shall affect the right of any Initial


                                       19
<PAGE>

Purchaser or Affiliated Market Maker or any person controlling such Initial
Purchaser or Affiliated Market Maker or any Indemnified Holder to serve process
in any other manner permitted by law. The Company further agrees to take any and
all action, including the execution and filing of any and all such documents and
instruments as may be necessary to continue such designation and appointment of
the Process Agent in full force and effect so long as the Company has any
outstanding obligations under this Agreement. To the extent that the Company has
or hereafter may acquire any immunity from jurisdiction of any court or from any
legal process (whether through service of note, attachment prior to judgment,
attachment in aid of execution, executor or otherwise) with respect to itself or
its property, the Company hereby irrevocably waives such immunity in respect of
their obligations under this Agreement, to the extent permitted by law.

     The provisions of this Section 10 shall survive any termination of this
Agreement, in whole or in part.

11   obligation currency

     The obligation of the parties to make payments hereunder is in U.S. dollars
(the "Obligation Currency") and such obligation shall not be discharged or
satisfied by any tender or recovery pursuant to any judgment expressed in or
converted into any currency other than the Obligation Currency or any other
realization in such other currency, whether as proceeds of set-off, security,
guarantee, distributions, or otherwise, except to the extent to which such
tender, recovery or realization shall result in the effective receipt by the
party which is to receive such payment of the full amount of the Obligation
Currency expressed to be payable hereunder, and the party liable to make such
payment agrees to indemnify the party which is to receive such payment (as an
additional, separate and independent cause of action) for the amount (if any) by
which such effective receipt shall fall short of the full amount of the
Obligation Currency expressed to be payable hereunder and such obligation to
indemnify shall not be affected by judgment being obtained for any other sums
due under this Agreement.

12   MISCELLANEOUS

     (a) Remedies. The Company acknowledges and agrees that any failure by the
Company to comply with its obligations under Sections 3 and 4 hereof may result
in material irreparable injury to the Initial Purchasers or the Holders or
Affiliated Market Makers for which there is no adequate remedy at law, that it
will not be possible to measure damages for such injuries precisely and that, in
the event of any such failure, the Initial Purchasers or any Holder or
Affiliated Market Maker may obtain such relief as may be required to
specifically enforce the Company's obligations under Sections 3 and 4 hereof.
The Company further agrees to waive the defense in any action for specific
performance that a remedy at law would be adequate.

     (b) No Inconsistent Agreements. The Company will not, on or after the date
of this Agreement, enter into any agreement with respect to its securities that
is inconsistent with the rights granted to the Holders in this Agreement or
otherwise conflicts with the provisions hereof. Except for the rights granted
pursuant to the Registration Rights Agreement dated December 23, 1998, among the
Company, Donaldson, Lufkin & Jenrette Securities Corporation and TD Securities
(USA) Inc., the Registration Rights Agreement dated July 28, 1999, among the
Company,



                                       20
<PAGE>

Donaldson, Lufkin & Jenrette Securities Corporation, Morgan Stanley & Co.
Incorporated, Salomon Smith Barney Inc. and TD Securities (USA) Inc. and the
Euro Registration Rights Agreement dated April 28, 2000, among the Company and
the initial purchasers listed thereto, the Company has not previously entered
into any agreement granting any registration rights with respect to its
securities to any Person. The rights granted to the Holders hereunder do not in
any way conflict with and are not inconsistent with the rights granted to the
holders of the Company's securities under any agreement in effect on the date
hereof.

     (c) Amendments and Waivers. The provisions of this Agreement may not be
amended, modified or supplemented, and waivers or consents to or departures from
the provisions hereof may not be given unless (i) in the case of Section 5
hereof and this Section 10(c)(i), the Company has obtained the written consent
of Holders of all outstanding Transfer Restricted Securities and (ii) in the
case of all other provisions hereof, the Company has obtained the written
consent of Holders of a majority of the outstanding principal amount of Transfer
Restricted Securities (excluding Transfer Restricted Securities held by the
Company or its Affiliates). Notwithstanding the foregoing, a waiver or consent
to departure from the provisions hereof that relates exclusively to the rights
of Holders whose Transfer Restricted Securities are being tendered pursuant to
the Exchange Offer, and that does not affect directly or indirectly the rights
of other Holders whose Transfer Restricted Securities are not being tendered
pursuant to such Exchange Offer, may be given by the Holders of a majority of
the outstanding principal amount of Transfer Restricted Securities subject to
such Exchange Offer.

     (d) Third Party Beneficiary. The Holders and Affiliated Market Makers shall
be third party beneficiaries to the agreements made hereunder between the
Company, on the one hand, and the Initial Purchasers, on the other hand, and
shall have the right to enforce such agreements directly to the extent they may
deem such enforcement necessary or advisable to protect its rights or the rights
of Holders and Affiliated Market Makers hereunder.

     (e) Notices. All notices and other communications provided for or permitted
hereunder shall be made in writing by hand-delivery, first-class mail
(registered or certified, return receipt requested), telex, telecopier, or air
courier guaranteeing overnight delivery:

          (i) if to a Holder, at the address set forth on the records of the
     Registrar under the Indenture, with a copy to the Registrar under the
     Indenture; and

          (ii) if to the Company:



               360networks inc.
               1510-1066 West Hastings Street
               Vancouver, BC Canada V6E 3X1
               Telecopier No.:  (604) 681-6822
               Attention:  Secretary

               with a copy to:



                                       21
<PAGE>

               Cahill Gordon & Reindel
               80 Pine Street
               New York, New York 10005
               Telecopier No.:  (212) 269-5420
               Attention:  Roger Andrus, Esq.

     All such notices and communications shall be deemed to have been duly
given: at the time delivered by hand, if personally delivered; five Business
Days after being deposited in the mail, postage prepaid, if mailed; when receipt
acknowledged, if telecopied; and on the next Business Day, if timely delivered
to an air courier guaranteeing overnight delivery.

     Copies of all such notices, demands or other communications shall be
concurrently delivered by the Person giving the same to the Trustee at the
address specified in the Indenture.

     Upon the date of filing of the Exchange Offer or a Shelf Registration
Statement, as the case may be, notice shall be delivered to Donaldson, Lufkin &
Jenrette Securities Corporation, on behalf of the Initial Purchasers (in the
form attached hereto as Exhibit A) and shall be addressed to: Attention: Louise
Guarneri (Compliance Department), 277 Park Avenue, New York, New York 10172.

     (f) Successors and Assigns. This Agreement shall inure to the benefit of
and be binding upon the successors and assigns of each of the parties, including
without limitation and without the need for an express assignment, subsequent
Holders; provided, that nothing herein shall be deemed to permit any assignment,
transfer or other disposition of Transfer Restricted Securities in violation of
the terms hereof or of the Purchase Agreement or the Indenture. If any
transferee of any Holder shall acquire Transfer Restricted Securities in any
manner, whether by operation of law or otherwise, such Transfer Restricted
Securities shall be held subject to all of the terms of this Agreement, and by
taking and holding such Transfer Restricted Securities such Person shall be
conclusively deemed to have agreed to be bound by and to perform all of the
terms and provisions of this Agreement, including the restrictions on resale set
forth in this Agreement and, if applicable, the Purchase Agreement, and such
Person shall be entitled to receive the benefits hereof.

     (g) Counterparts. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

     (h) Headings. The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

     (i) Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO THE
CONFLICT OF LAW RULES THEREOF.

     (j) Severability. In the event that any one or more of the provisions
contained herein, or the application thereof in any circumstance, is held
invalid, illegal or unenforceable, the validity,



                                       22
<PAGE>

legality and enforceability of any such provision in every other respect and of
the remaining provisions contained herein shall not be affected or impaired
thereby.

     (k) Entire Agreement. This Agreement is intended by the parties as a final
expression of their agreement and intended to be a complete and exclusive
statement of the agreement and understanding of the parties hereto in respect of
the subject matter contained herein. There are no restrictions, promises,
warranties or undertakings, other than those set forth or referred to herein
with respect to the registration rights granted with respect to the Transfer
Restricted Securities. This Agreement supersedes all prior agreements and
understandings between the parties with respect to such subject matter.





                                       23
<PAGE>



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



                                   360networks inc.


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



DONALDSON, LUFKIN & JENRETTE SECURITIES CORPORATION
GOLDMAN, SACHS & CO.
BEAR, STEARNS & CO. INC.
CHASE SECURITIES INC.
CREDIT SUISSE FIRST BOSTON CORPORATION
MORGAN STANLEY & CO. INCORPORATED
SALOMON SMITH BARNEY INC.
RBC DOMINION SECURITIES CORPORATION
TD SECURITIES (USA) INC.

By:  DONALDSON, LUFKIN & JENRETTE SECURITIES CORPORATION,
      as representative of the several underwriters

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





                                       24
<PAGE>



                                    EXHIBIT A

                               NOTICE OF FILING OF
                    A/B EXCHANGE OFFER REGISTRATION STATEMENT


To:      Donaldson, Lufkin & Jenrette Securities Corporation
         277 Park Avenue
         New York, New York  10172
         Attention:  Louise Guarneri (Compliance Department)
         Fax: (212) 892-7272

From:    360networks inc.
         __% Senior Dollar Notes due 2008
         __% Senior Dollar Notes due 2010

Date: _____, 2000

     For your information only (NO ACTION REQUIRED):

     Today, ______, 2000, we filed [an A/B Exchange Registration Statement/a
Shelf Registration Statement] with the Securities and Exchange Commission. We
currently expect this registration statement to be declared effective within __
Business Days of the date hereof.




                                      A-1