<PAGE>

                                                                    Exhibit 4.9


                                                                  EXECUTION COPY
                                  $200,000,000

                                CREDIT AGREEMENT

                          Dated as of December 21, 1999

                                      Among

                          CARRIER 1 INTERNATIONAL S.A.

                                    AS PARENT

                           THE BORROWERS NAMED HEREIN

                                  AS BORROWERS

                           THE GUARANTORS NAMED HEREIN

                                  AS GUARANTORS

                                       and

                        THE INITIAL LENDERS NAMED HEREIN

                               AS INITIAL LENDERS

                                       and

                       MORGAN STANLEY SENIOR FUNDING, INC.

                                       and

                                 CITIBANK, N.A.

                                AS LEAD ARRANGERS


                       MORGAN STANLEY SENIOR FUNDING, INC.

                   AS ADMINISTRATIVE AGENT AND SECURITY AGENT


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                                TABLE OF CONTENTS

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                                                                                                           PAGE
         <S>            <C>                                                                                 <C>
                    ARTICLE I   DEFINITIONS AND ACCOUNTING TERMS
         SECTION 1.01.  CERTAIN DEFINED TERMS.................................................................1
         SECTION 1.02.  OTHER DEFINED TERMS..................................................................27
         SECTION 1.03.  COMPUTATION OF TIME PERIODS..........................................................27
         SECTION 1.04.  ACCOUNTING TERMS.....................................................................27

                   ARTICLE II  AMOUNTS AND TERMS OF THE ADVANCES
         SECTION 2.01.  THE ADVANCES.........................................................................27
         SECTION 2.02.  MAKING THE ADVANCES..................................................................28
         SECTION 2.03.  FEES.................................................................................29
         SECTION 2.04.  TERMINATION OR REDUCTION OF THE COMMITMENTS..........................................29
         SECTION 2.05.  REPAYMENT............................................................................29
         SECTION 2.06.  INTEREST.............................................................................30
         SECTION 2.07.  INTEREST RATE DETERMINATION..........................................................30
         SECTION 2.08.  PREPAYMENTS..........................................................................31
         SECTION 2.09.  INCREASED COSTS......................................................................31
         SECTION 2.10.  ILLEGALITY...........................................................................32
         SECTION 2.11.  PAYMENTS AND COMPUTATIONS............................................................33
         SECTION 2.12.  TAXES................................................................................34
         SECTION 2.13.  RULES................................................................................35
         SECTION 2.14.  SHARING OF PAYMENTS, ETC.............................................................36
         SECTION 2.15.  EVIDENCE OF INDEBTEDNESS.............................................................36
         SECTION 2.16.  USE OF PROCEEDS......................................................................37
         SECTION 2.17.  REMOVAL OF LENDER....................................................................37
         SECTION 2.18.  CERTAIN RULES RELATING TO THE PAYMENT OF ADDITIONAL AMOUNTS..........................37

                        ARTICLE III  CONDITIONS TO LENDING
         SECTION 3.01.  CONDITIONS PRECEDENT.................................................................37
         SECTION 3.02.  CONDITIONS PRECEDENT TO CERTAIN BORROWINGS.  ........................................39
         SECTION 3.03.  CONDITIONS PRECEDENT TO EACH BORROWING...............................................42
         SECTION 3.04.  DETERMINATIONS UNDER SECTION 3.01....................................................42

                    ARTICLE IV  REPRESENTATIONS AND WARRANTIES
         SECTION 4.01.  REPRESENTATIONS AND WARRANTIES.......................................................42

                               ARTICLE V  COVENANTS
         SECTION 5.01.  AFFIRMATIVE COVENANTS................................................................46
         SECTION 5.02.  NEGATIVE COVENANTS...................................................................49
         SECTION 5.03.  FINANCIAL COVENANT...................................................................63
         SECTION 5.04.  LIMITATION ON PARENT ACTIVITIES......................................................63



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         <S>            <C>                                                                                 <C>
                           ARTICLE VI  EVENTS OF DEFAULT
         SECTION 6.01.  EVENTS OF DEFAULT....................................................................64

                              ARTICLE VII  THE AGENTS
         SECTION 7.01.  AUTHORIZATION AND ACTION.............................................................66
         SECTION 7.02.  AGENT'S RELIANCE, ETC................................................................67
         SECTION 7.03.  MSSF AND AFFILIATES..................................................................67
         SECTION 7.04.  LENDER CREDIT DECISION...............................................................67
         SECTION 7.05.  INDEMNIFICATION......................................................................68
         SECTION 7.06.  SUCCESSOR AGENT......................................................................68

                                  ARTICLE VIII
                                                       GUARANTEE.............................................69
         SECTION 8.01.  GUARANTEE............................................................................69
         SECTION 8.02.  GUARANTEE ABSOLUTE...................................................................70
         SECTION 8.03.  WAIVERS AND ACKNOWLEDGMENTS..........................................................70
         SECTION 8.04.  SUBROGATION..........................................................................71
         SECTION 8.05.  CONTINUING GUARANTEE.................................................................71

                             ARTICLE IX  MISCELLANEOUS
         SECTION 9.01.  AMENDMENTS, ETC......................................................................72
         SECTION 9.02.  NOTICES, ETC.........................................................................72
         SECTION 9.03.  NO WAIVER; REMEDIES..................................................................73
         SECTION 9.04.  COSTS AND EXPENSES...................................................................73
         SECTION 9.05.  RIGHT OF SET-OFF.....................................................................74
         SECTION 9.06.  BINDING EFFECT.......................................................................74
         SECTION 9.07.  ASSIGNMENTS AND PARTICIPATIONS.......................................................75
         SECTION 9.08.  CONFIDENTIALITY......................................................................77
         SECTION 9.09.  GOVERNING LAW........................................................................77
         SECTION 9.10.  EXECUTION IN COUNTERPARTS............................................................77
         SECTION 9.11.  JUDGMENT.............................................................................77
         SECTION 9.12.  JURISDICTION, ETC....................................................................78
         SECTION 9.13.  WAIVER OF JURY TRIAL.................................................................79

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                                                                            PAGE

SCHEDULES

Schedule 1 - Initial Lenders and Commitments

Schedule 4.01(a) - Corporate Structure Chart

EXHIBITS

Exhibit A-1 - List of Borrowers

Exhibit A-2 - List of Guarantors

Exhibit B - Form of Notice of Borrowing

Exhibit C - Form of Assignment and Acceptance

Exhibit D - Form of Opinion of Local Counsel for the Loan Parties

Exhibit E - Form of Accession Agreement

Exhibit F - Name and Address of Process Agent


<PAGE>


                                CREDIT AGREEMENT

                          Dated as of December 21, 1999


Carrier 1 International S.A., a societe anonyme organized under the laws of the
Grand Duchy of Luxembourg, as parent (the "PARENT"), certain subsidiaries of the
Parent listed on Exhibit A-1 hereto as borrowers (together with any Acceding
Borrowers (as defined below), the "BORROWERS") certain subsidiaries of the
Parent listed on Exhibit A-2 hereto as guarantors (together with any Acceding
Guarantors (as defined below), the "GUARANTORS"), the banks, financial
institutions and other institutional lenders (the "INITIAL LENDERS") listed on
the signature pages hereof, Morgan Stanley Senior Funding, Inc. ("MSSF") and
Citibank, N.A., as lead arrangers (collectively, the "LEAD ARRANGERS"), MSSF, as
security agent (together with any successor appointed pursuant to Article VII
hereof, the "SECURITY AGENT"), MSSF, as administrative agent (together with any
successor appointed pursuant to Article VII hereof, the "ADMINISTRATIVE AGENT")
for the Lenders (as hereinafter defined), agree as follows:


                                    ARTICLE I

                        DEFINITIONS AND ACCOUNTING TERMS

                  SECTION 1.01. CERTAIN DEFINED TERMS. As used in this
Agreement, the following terms shall have the following meanings (such meanings
to be equally applicable to both the singular and plural forms of the terms
defined):

                  "ACCEDING BORROWER" means each additional borrower named by
         the Parent as to which the conditions set forth in Section 3.03(b)
         hereof have been met.

                  "ACCEDING GUARANTOR" means each Person who has executed and
         delivered to the Administrative Agent an accession agreement in the
         form of Exhibit E hereto.

                  "ACQUIRED INDEBTEDNESS" means Indebtedness of a Person
         existing at the time such Person becomes a Restricted Subsidiary or is
         merged with or consolidated with a Restricted Subsidiary or assumed in
         connection with an Asset Acquisition by a Restricted Subsidiary and not
         Incurred in connection with, or in anticipation of, such Person
         becoming a Restricted Subsidiary or such Asset Acquisition.

                  "ADJUSTED CONSOLIDATED NET INCOME" means, for any period, the
         aggregate net income (or loss) of the Parent and its Restricted
         Subsidiaries for such period determined on a consolidated basis in
         conformity with GAAP; PROVIDED that the following items shall be
         excluded in computing Adjusted Consolidated Net Income (without
         duplication):

                  (i) the net income (or loss) of any Person that is not a
         Restricted Subsidiary, except (x) with respect to net income, to the
         extent of the amount of dividends or other distributions actually paid
         to the Parent or any of its Restricted Subsidiaries by such


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                                       2


         Person during such period and (y) with respect to net losses, to the
         extent of the amount of Investments made by the Parent or any
         Restricted Subsidiary in such Person during such period;

                  (ii) solely for the purposes of calculating the amount of
         Restricted Payments that may be made pursuant to Clause III of Section
         5.02(b)(i)(C) hereof (and in such case, except to the extent includable
         pursuant to clause (i) above), the net income (or loss) of any Person
         accrued prior to the date it becomes a Restricted Subsidiary or is
         merged into or consolidated with the Parent or any of its Restricted
         Subsidiaries or all or substantially all of the property and assets of
         such Person are acquired by the Parent or any of its Restricted
         Subsidiaries;

                  (iii) the net income of any Restricted Subsidiary to the
         extent that the declaration or payment of dividends or similar
         distributions by such Restricted Subsidiary of such net income is not
         at the time permitted (after giving effect to any effective waiver,
         consent or approval) by the operation of the terms of its charter or
         any agreement, instrument, judgment, decree, order, statute, rule or
         governmental regulation applicable to such Restricted Subsidiary;

                  (iv) any gains or losses attributable to Asset Sales (without
         regard to clause (c) or (d) in the proviso to the definition thereof);

                  (v) solely for purposes of calculating the amount of
         Restricted Payments that may be made pursuant to Clause III of Section
         5.02(b)(i)(C) hereof, any amount paid or accrued as dividends on
         Preferred Stock of the Parent or any Restricted Subsidiary owned by
         Persons other than the Parent and any of its Restricted Subsidiaries;

                  (vi) all extraordinary gains and extraordinary losses or
         extraordinary charges;

                  (vii) any compensation expense to the extent paid or payable
         solely with Capital Stock (other than Disqualified Stock) of the Parent
         or any options, warrants or other rights to acquire Capital Stock
         (other than Disqualified Stock) of the Parent; and

                  (viii) the cumulative effect of a change in accounting
         principles.

                  "ADJUSTED CONSOLIDATED NET TANGIBLE ASSETS" means the total
         amount of assets of the Parent and its Restricted Subsidiaries (less
         applicable depreciation, amortization and other valuation reserves),
         except to the extent resulting from write-ups of capital assets
         (excluding write-ups in connection with accounting for acquisitions in
         conformity with GAAP), after deducting therefrom (i) all current
         liabilities of the Parent and its Restricted Subsidiaries (excluding
         intercompany items) and (ii) all goodwill, trade names, trademarks,
         patents, unamortized debt discount and expense and other like
         intangibles, all as set forth on the most recent quarterly or annual
         consolidated balance sheet of the Parent and its Restricted
         Subsidiaries, prepared in conformity with GAAP and filed with the
         Commission or provided to the Administrative Agent.


<PAGE>
                                       3


                  "ADMINISTRATIVE AGENT'S ACCOUNT" means (i) with respect to
         Advances denominated in Dollars, the account of the Administrative
         Agent maintained by the Administrative Agent with Citibank, N.A. at its
         office in New York, New York, Account No. 406-99-776, Attention: Liz
         Frattaroli and (ii) with respect to Advances denominated in Euros, the
         account of the Administrative Agent maintained by the Administrative
         Agent with Banque Paribas at its office in Paris, France, Account No.
         001000-0000-46961A, Attention: Liz Frattaroli, or such other account or
         accounts as the Administrative Agent may notify to the Parent and the
         Lenders from time to time.

                  "ADVANCE" means an advance by a Lender to a Borrower pursuant
         to Article II.

                  "AFFILIATE" means, as to any Person, any other Person directly
         or indirectly controlling, controlled by or under direct or indirect
         common control with, such Person. For purposes of this definition, the
         term "control" (including with correlative meanings the terms
         "controlling", "controlled by" and "under common control with") as
         applied to any Person means the possession, directly or indirectly, of
         the power to direct or cause the direction of the management and
         policies of such Person, whether through the ownership of voting
         securities, by contract or otherwise.

                  "AGENT" means any of the Administrative Agent, the Security
         Agent or the Lead Arrangers.

                  "APPLICABLE MARGIN" means 3.25% per annum; PROVIDED, HOWEVER,
         that if the condition precedent with respect to the German Pledge
         Agreement contained in Section 3.02(a)(iv) hereof has not been
         satisfied on or before the Closing Date, then for so long as the
         Pledged Shares do not include the Pledged Shares pledged pursuant to
         such German Pledge Agreement or other Pledged Shares which fully secure
         the initial Borrowing (as determined by the Administrative Agent in its
         reasonable discretion taking into consideration its customary secured
         lending policies), the Applicable Margin otherwise in effect will be
         6%; PROVIDED, FURTHER, that if the Advances are not paid in full by
         June 30, 2000, the Applicable Margin otherwise in effect shall increase
         by 0.50% and shall thereafter increase by an additional 0.50% at the
         end of each subsequent calendar quarter until the repayment in full of
         the Advances; PROVIDED, FURTHER, that, in no event shall the Applicable
         Margin exceed 4.75%, other than as referred to in the first proviso of
         this definition or pursuant to Section 2.06(b) hereof.

                 "ASSET ACQUISITION" means (i) an investment by the Parent or
         any of its Restricted Subsidiaries in any other Person pursuant to
         which such Person shall become a Restricted Subsidiary or shall be
         merged into or consolidated with the Parent or any of its Restricted
         Subsidiaries; PROVIDED that such Person's primary business is related,
         ancillary or complementary to the businesses of the Parent and its
         Restricted Subsidiaries on the date of such investment as determined in
         good faith by the Board of Directors (whose determination shall be
         conclusive and evidenced by a Board Resolution) or (ii) an acquisition
         by the Parent or any of its Restricted Subsidiaries of the property and
         assets of any Person other than the Parent or any of its Restricted
         Subsidiaries that constitute substantially all of a division or line of
         business of such Person; PROVIDED that the property


<PAGE>
                                       4


         and assets acquired are related, ancillary or complementary to the
         businesses of the Parent and its Restricted Subsidiaries on the date
         of such acquisition as determined in good faith by the Board of
         Directors (whose determination shall be conclusive and evidenced by a
         Board Resolution).

                  "ASSET DISPOSITION" means the sale or other disposition by the
         Parent or any of its Restricted Subsidiaries (other than to the Parent
         or another Restricted Subsidiary) of (i) all or substantially all of
         the Capital Stock of any Restricted Subsidiary or (ii) all or
         substantially all of the assets that constitute a division or line of
         business of the Parent or any of its Restricted Subsidiaries.

                  "ASSET SALE" means any sale, transfer or other disposition
         (including by way of merger, consolidation or sale-leaseback
         transaction) in one transaction or a series of related transactions by
         the Parent or any of its Restricted Subsidiaries to any Person other
         than the Parent or any of its Restricted Subsidiaries of (i) all or any
         of the Capital Stock of any Restricted Subsidiary, (ii) all or
         substantially all of the property and assets of an operating unit or
         business of the Parent or any of its Restricted Subsidiaries or (iii)
         any other property and assets (other than the Capital Stock or other
         Investment in an Unrestricted Subsidiary) of the Parent or any of its
         Restricted Subsidiaries outside the ordinary course of business of the
         Parent or such Restricted Subsidiary and, in each case, that is not
         governed by Section 5.02(j); PROVIDED that "ASSET SALE" shall not
         include (a) sales, transfers or other dispositions of Temporary Cash
         Investments, inventory, receivables and other current assets, (b)
         sales, transfers or other dispositions of assets constituting a
         Restricted Payment (or a transaction excluded from the definition of
         the term "RESTRICTED PAYMENTS") permitted to be made under Section
         5.02(b), (c) for purposes of Section 2.08(b) only, sales of ducts, dark
         fiber, lit fiber and capacity and fiber swaps outside the ordinary
         course of business and contemplated by the most recent business plan of
         the Parent as presented to the Lenders from time to time or (d) sales,
         transfers or other dispositions of assets with a fair market value (as
         certified in an officer's certificate) not in excess of $2 million in
         any transaction.

                  "ASSIGNMENT AND ACCEPTANCE" means an assignment and acceptance
         entered into by a Lender and an Eligible Assignee, and accepted by the
         Administrative Agent, in substantially the form of Exhibit C hereto.

                  "AVERAGE LIFE" means, at any date of determination with
         respect to any Indebtedness, the quotient obtained by dividing (i) the
         sum of the products of (a) the number of years from such date of
         determination to the dates of each successive scheduled principal
         payment of such Indebtedness and (b) the amount of such principal
         payment by (ii) the sum of all such principal payments.

                  "BOARD OF DIRECTORS" means the Board of Directors or other
         corporate governing body of the Parent or any committee of such Board
         of Directors duly authorized to act.


<PAGE>
                                       5


                  "BOARD RESOLUTIONS" means a copy of a resolution of the Board
         of Directors of the Parent certified to have been duly adopted by the
         Board of Directors and to be in full force and effect on the date of
         such adoption, delivered to the Administrative Agent.

                  "BORROWING" means a borrowing consisting of Advances in the
         same Permitted Currency and having the same Interest Period.

                  "BRIDGE FACILITY" means the $200 million bridge financing
         facility provided hereunder.

                  "BUSINESS DAY" means a day of the year banks are not required
         or authorized by law to close in New York City and on which dealings
         are carried on in the London interbank market and, for payments of
         interest and determination of interest rates in respect of Advances
         denominated in Euros, on which the Trans-European Automated Real-Time
         Gross Settlement Express Transfer (TARGET) System is in operation.

                  "CAPITAL STOCK" means, with respect to any Person, any and all
         shares, interests, participations or other equivalents (however
         designated, whether voting or non-voting) in equity of such Person,
         whether outstanding on the Closing Date or issued thereafter,
         including, without limitation, all Common Stock and Preferred Stock.

                  "CAPITALIZED LEASE" means, as applied to any Person, any lease
         of any property (whether real, personal or mixed) of which the
         discounted present value of the rental obligations of such Person as
         lessee, in conformity with GAAP, is required to be capitalized on the
         balance sheet of such Person.

                  "CAPITALIZED LEASE OBLIGATIONS" means the discounted present
         value of the rental obligations under a Capitalized Lease.

                  "CHANGE OF CONTROL" means such time as (i) a "person" or
         "group" (within the meaning of Section 13(d) or 14(d)(2) under the
         Exchange Act) becomes the ultimate "beneficial owner" (as defined in
         Rule 13d-3 under the Exchange Act) of more than 35% (50%, if the
         Permitted Holders hold more than 35% of the voting power of the Voting
         Stock of the Parent on a fully diluted basis) of the total voting power
         of the Voting Stock of the Parent on a fully diluted basis and such
         ownership represents a greater percentage of the total voting power of
         the Voting Stock of the Parent, on a fully diluted basis, than is held
         by Permitted Holders on such date; or (ii) during any period of two
         consecutive years beginning on or after the Closing Date, individuals
         who at the beginning of such period were members of the Board of
         Directors (together with any new directors whose election by the Board
         of Directors or whose nomination for election by the Parent's
         shareholders was approved by a vote of at least a majority of the
         members of the Board of Directors then in office who either were
         members of the Board of Directors at the beginning of such period or
         whose election or nomination for election was previously so approved)
         cease for any reason to constitute a majority of the members of the
         Board of Directors then in office.


<PAGE>
                                       6


                  "CLOSING DATE" means December 21, 1999 or such later date to
         which the Parent consents; PROVIDED, HOWEVER, that the Closing Date
         shall not occur during the Restricted Period unless the Initial Lenders
         in their sole discretion consent.

                  "COMMISSION" means the Securities and Exchange Commission, as
         from time to time constituted, created under the Exchange Act or, if at
         any time after the execution of this instrument such Commission is not
         existing and performing the duties now assigned to it, then the body
         performing such duties at such time.

                  "COMMITMENT" has the meaning specified in Section 2.01 hereof.

                  "COMMON STOCK" means, with respect to any Person, any and all
         shares, interests, participations or other equivalents (however
         designated, whether voting or non-voting) of such Person's equity,
         other than Preferred Stock of such Person, whether outstanding on the
         Closing Date or issued thereafter, including, without limitation all
         series and classes of such common stock.

                  "CONFIDENTIAL INFORMATION" means information that the Parent
         furnishes to the Administrative Agent or any Lender in a writing
         pursuant to or in connection with this Agreement, but does not include
         any such information that is or becomes generally available to the
         public or that is or becomes available to the Administrative Agent or
         such Lender from a source other than the Parent.

                  "CONSOLIDATED ADJUSTED EBITDA" means, for any period, Adjusted
         Consolidated Net Income for such period plus, to the extent such amount
         was deducted in calculating such Adjusted Consolidated Net Income, (i)
         Consolidated Interest Expense, (ii) provision for all taxes based on
         income, profits or capital, (iii) depreciation expense, (iv)
         amortization expense (including but not limited to amortization of
         goodwill and intangibles and amortization and write-off of financing
         costs) and (v) all other non-cash items reducing Adjusted Consolidated
         Net Income (other than items that will require cash payments and for
         which an accrual or reserve is, or is required by GAAP to be, made),
         less all non-cash items increasing Adjusted Consolidated Net Income
         (other than any item reversing, offsetting or reducing any such accrual
         or reserve), all as determined on a consolidated basis for the Parent
         and its Restricted Subsidiaries in conformity with GAAP; PROVIDED that,
         if any Restricted Subsidiary is not a Wholly Owned Restricted
         Subsidiary, Consolidated Adjusted EBITDA shall be reduced (to the
         extent not otherwise reduced in accordance with GAAP) by an amount
         equal to (A) the amount of the Adjusted Consolidated Net Income
         attributable to such Restricted Subsidiary multiplied by (B) the
         percentage ownership interest in the income of such Restricted
         Subsidiary not owned on the last day of such period by the Parent or
         any of its Restricted Subsidiaries.

                  "CONSOLIDATED INTEREST EXPENSE" means, for any period, the
         aggregate amount of interest in respect of Indebtedness (including,
         without limitation, amortization of original issue discount on any
         Indebtedness and the interest portion of any deferred payment
         obligation, calculated in accordance with the effective interest method
         of accounting; all commissions, discounts and other fees and charges
         owed with respect to letters of credit


<PAGE>
                                       7


         and bankers' acceptance financing; the net costs associated with Hedge
         Agreements; and interest on Indebtedness that is Guaranteed or secured
         by the Parent or any of its Restricted Subsidiaries) and the interest
         component of Capitalized Lease Obligations paid, accrued or scheduled
         to be paid or to be accrued by the Parent and its Restricted
         Subsidiaries during such period, all as determined on a consolidated
         basis (without taking into account Unrestricted Subsidiaries) in
         conformity with GAAP.

                  "CONSOLIDATED LEVERAGE RATIO" means, on any Transaction Date,
         the ratio of (i) the aggregate amount of Indebtedness of the Parent and
         its Restricted Subsidiaries on a consolidated basis outstanding on such
         Transaction Date to (ii) four times the amount of Consolidated Adjusted
         EBITDA for the then most recent fiscal quarter for which financial
         statements of the Parent have been filed with the Commission or
         provided to the Administrative Agent under this Agreement (such quarter
         being the "QUARTER"); PROVIDED that, in making the foregoing
         calculation, (A) pro forma effect shall be given, in calculating the
         amount of Indebtedness outstanding on the Transaction Date, to any
         Indebtedness to be Incurred on the Transaction Date, or to be repaid,
         repurchased, redeemed or otherwise retired or discharged on the
         Transaction Date; (B) pro forma effect shall be given to Asset
         Dispositions and Asset Acquisitions (including giving pro forma effect
         to the application of proceeds of any Asset Disposition) that occur
         from the beginning of the Quarter through the Transaction Date (the
         "REFERENCE PERIOD"), as if they had occurred and such proceeds had been
         applied on the first day of such Reference Period; and (C) pro forma
         effect shall be given to asset dispositions and asset acquisitions
         (including giving pro forma effect to the application of proceeds of
         any asset disposition) that have been made by any Person that has
         become a Restricted Subsidiary or has been merged with or into, or
         consolidated with, the Parent or any Restricted Subsidiary during such
         Reference Period and that would have constituted Asset Dispositions or
         Asset Acquisitions had such transactions occurred when such Person was
         a Restricted Subsidiary as if such asset dispositions or asset
         acquisitions were Asset Dispositions or Asset Acquisitions that
         occurred on the first day of such Reference Period; PROVIDED that to
         the extent that clause (B) or (C) of this sentence requires that pro
         forma effect be given to an Asset Acquisition or Asset Disposition,
         such pro forma calculation shall be based upon the full fiscal quarter
         immediately preceding the Transaction Date of the Person, or division
         or line of business of the Person, that is acquired or disposed of for
         which financial information is available.

                  "CONSOLIDATED NET WORTH" means, at any date of determination,
         shareholders' equity (plus, to the extent not otherwise included,
         Preferred Stock of the Parent) as set forth on the most recently
         available quarterly or annual consolidated balance sheet of the Parent
         and its Restricted Subsidiaries (which shall be as of a date not more
         than 90 days prior to the date of such computation, and which shall not
         take into account Unrestricted Subsidiaries), less any amounts
         attributable to Disqualified Stock or any equity security convertible
         into or exchangeable for Indebtedness, the cost of treasury stock and
         the principal amount of any promissory notes receivable from the sale
         of the Capital Stock of the Parent or any of its Restricted
         Subsidiaries, each item to be determined in conformity with GAAP
         (excluding the effects of foreign currency exchange adjustments


<PAGE>
                                       8


         under Financial Accounting Standards Board Statement of Financial
         Accounting Standards No. 52).

                  "DEFAULT" means any event that is, or after notice or passage
         of time or both would be, an Event of Default.

                  "DISQUALIFIED STOCK" means any class or series of Capital
         Stock of any Person that by its terms or otherwise is (i) required to
         be redeemed prior to the Stated Maturity of the Advances, (ii)
         redeemable at the option of the holder of such class or series of
         Capital Stock at any time prior to the Stated Maturity of the Advances
         or (iii) convertible into or exchangeable for Capital Stock referred to
         in clause (i) or (ii) above or Indebtedness having a scheduled maturity
         prior to the Stated Maturity of the Advances; PROVIDED that any Capital
         Stock that would not constitute Disqualified Stock but for provisions
         thereof giving holders thereof the right to require such Person to
         repurchase or redeem such Capital Stock upon the occurrence of an
         "asset sale" or "change of control" occurring prior to the Stated
         Maturity of the Advances shall not constitute Disqualified Stock to the
         extent permitted under the Indentures as in effect on the date hereof.

                  "DOLLARS" and "$" means the lawful currency of the United
         States of America.

                  "EBITDA" means, for any period, the sum of the following
         determined on a Consolidated basis for the Parent and its Subsidiaries
         in accordance with GAAP: (a) losses from operations for such period
         PLUS (a) the sum of the following to the extent deducted in determining
         losses from operations: (i) amortization and (ii) depreciation. For the
         avoidance of doubt, the following items shall not be added back in
         determining EBITDA: (i) interest income, (ii) interest expense, (iii)
         certain other items as contemplated by the financial model provided to
         the Lead Arrangers prior to the date hereof, (iv) depreciation of
         financing costs capitalized and (v) currency exchange gain (loss).

                  "ELIGIBLE ASSIGNEE" means (i) a Lender; (ii) an Affiliate of a
         Lender; and (iii) (a) a commercial bank, savings and loan association,
         savings bank or other similar banking organization having a combined
         capital and surplus of at least $250 million, (b) a finance company,
         insurance company or other financial institution or fund (whether a
         corporation, partnership, trust or other entity) that is engaged in
         making, purchasing or otherwise investing in commercial loans in the
         ordinary course of its business and having total assets in excess of
         $250 million, (c) telecommunications equipment vendors and related
         entities and (d) any other Person approved by the Administrative Agent
         of the type included in this clause (iii).

                  "ENVIRONMENTAL LAW" means any national state or local statute,
         law, ordinance, rule, regulation, code, order, judgment, decree or
         judicial or agency interpretation, policy or guidance relating to
         pollution or protection of the environment, health, safety or natural
         resources, including, without limitation, those relating to the use,
         handling, transportation, treatment, storage, disposal, release or
         discharge of Hazardous Materials.


<PAGE>
                                       9


                  "EQUIVALENT" in Dollars of Euros on any date means the
         equivalent in Dollars of Euros determined by using the spot rate at
         which the Administrative Agent's principal office in London offers to
         exchange Dollars for Euros in London prior to noon (London time) on
         such date as is required pursuant to the terms of this Agreement.

                  "ERISA" means the Employee Retirement Income Security Act of
         1974, as amended from time to time, and the regulations promulgated and
         rulings issued thereunder.

                  "ERISA AFFILIATE" means any Person that for purposes of Title
         IV of ERISA is a member of the Parent's controlled group, or under
         common control with the Parent, within the meaning of Section 414 of
         the Internal Revenue Code.

                  "ERISA EVENT" means (a) (i) the occurrence of a reportable
         event, within the meaning of Section 4043 of ERISA, with respect to any
         Plan unless the 30-day notice requirement with respect to such event
         has been waived by the PBGC, or (ii) the requirements of subsection (1)
         of Section 4043(b) of ERISA (without regard to subsection (2) of such
         Section) are met with respect to a contributing sponsor, as defined in
         Section 4001(a)(13) of ERISA, of a Plan, and an event described in
         paragraph (10), (11), (12) or (13) of Section 4043(c) of ERISA is
         reasonably expected to occur with respect to such Plan within the
         following 30 days; (b) the application for a minimum funding waiver
         with respect to a Plan; (c) the provision by the administrator of any
         Plan of a notice of intent to terminate such Plan pursuant to Section
         4041(c) of ERISA; (d) the cessation of operations at a facility of the
         Parent or any ERISA Affiliate in the circumstances described in Section
         4062(e) of ERISA or other withdrawal by the Parent or any ERISA
         Affiliate from a Multiple Employer Plan during a plan year for which it
         was a substantial employer, as defined in Section 4001(a)(2) of ERISA
         which is reasonably expected to result in liability under Section 4043
         of ERISA; (e) the conditions for the imposition of a lien under Section
         302(f) of ERISA shall have been met with respect to any Plan; (g) the
         adoption of an amendment to a Plan requiring the provision of security
         to such Plan pursuant to Section 307 of ERISA; or (h) the institution
         by the PBGC of proceedings to terminate a Plan pursuant to Section 4042
         of ERISA, or the occurrence of any event or condition described in
         Section 4042 of ERISA that constitutes grounds for the termination of,
         or the appointment of a trustee to administer, a Plan.

                  "EURO" and the "_" sign mean the single currency of
         Participating Member States introduced at the start of the third stage
         of Economic and Monetary Union pursuant to the Treaty of European
         Union.

                  "EURO LIBOR" means for any Interest Period for each Advance
         denominated in Euros, an interest rate equal to the rate for deposits
         in Euros which appears on Telerate page 3750 (or any other page that
         might replace this page in this service) as of 11:00 a.m. London time
         two Business Days before the first day of such Interest Period;
         PROVIDED, that, if for any reason such rate is not available, the term
         "Euro LIBOR" shall mean the average of the rates at which deposits in
         Euros are offered by the Reference Banks at


<PAGE>
                                       10


         approximately 11:00 a.m. London time on such date to prime banks in
         the Euro-zone interbank market.

                  "EVENTS OF DEFAULT" has the meaning specified in Section 6.01.

                  "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
         amended.

                  "EXTRAORDINARY RECEIPT" means any cash receipts received by or
         paid to or for the account of any Person from proceeds of property
         insurance and condemnation awards (and payments in lieu thereof);
         PROVIDED, HOWEVER, that an Extraordinary Receipt shall not include (i)
         cash receipts received from proceeds of property insurance or
         condemnation awards (or payments in lieu thereof) to the extent such
         proceeds, awards or payments in respect of loss or damage to equipment,
         fixed assets or real or personal property are applied (or in respect of
         which expenditures were previously incurred) to replace or repair the
         equipment, fixed assets or real or personal property in respect of
         which such proceeds were received in accordance with the terms of the
         Loan Documents, (ii) tax refunds and (iii) other cash receipts in the
         ordinary course of business.

                  "FAIR MARKET VALUE" means the price that would be paid in an
         arm's-length transaction between an informed and willing seller under
         no compulsion to sell and an informed and willing buyer under no
         compulsion to buy, as determined in good faith by the Board of
         Directors, whose determination shall be conclusive if evidenced by a
         Board Resolution; PROVIDED that for purposes of Section 5.02(a)(i)(G)
         hereof, (x) the fair market value of any security registered under the
         Exchange Act shall be the average of the closing prices, regular way,
         of such security for the 20 consecutive trading days immediately
         preceding the sale of Capital Stock and (y) in the event the aggregate
         fair market value of any other property (other than cash or cash
         equivalents) received by the Parent exceeds $10 million, the fair
         market value of such property shall be determined by a nationally
         recognized investment banking or appraisal firm and set forth in their
         written opinion which shall be delivered to the Administrative Agent.

                  "GAAP" means generally accepted accounting principles in the
         United States of America as in effect as of the Closing Date,
         including, without limitation, those set forth in the opinions and
         pronouncements of the Accounting Principles Board of the American
         Institute of Certified Public Accountants and statements and
         pronouncements of the Financial Accounting Standards Board or in such
         other statements by such other entity as approved by a significant
         segment of the accounting profession; PROVIDED, HOWEVER, that all
         reports and other financial information provided by the Parent
         hereunder shall be prepared in accordance with GAAP as in effect from
         time to time. All ratios and computations contained or referred to in
         this Agreement shall be computed in conformity with GAAP applied on a
         consistent basis, except that calculations made for purposes of
         determining compliance with the terms of the covenants and with other
         provisions of this Agreement shall be made without giving effect to (i)
         the amortization or write-off of any expenses incurred in connection
         with the offering of the Units (as defined in the Indentures) and (ii)
         the amortization of any amounts required or permitted by Accounting
         Principles Board Opinion Nos. 16 and 17.


<PAGE>
                                       11


                  "GERMAN NETWORK" means the fiber optic network to be built in
         the Federal Republic of Germany by the Parent or any of its Restricted
         Subsidiaries with affiliates of Viatel, Inc. and Metromedia Fiber
         Network Inc. contemplated by the letter of intent dated August 20,1998.

                  "GERMAN NETWORK L/C" means a letter of credit in an amount not
         to exceed $85 million, as issued, amended, supplemented or modified
         from time to time, to secure obligations of the Parent or any of its
         Restricted Subsidiaries with respect to the German Network.

                  "GUARANTEE" means any obligation, contingent or otherwise, of
         any Person directly or indirectly guaranteeing any Indebtedness of any
         other Person and, without limiting the generality of the foregoing, any
         such obligation, direct or indirect, contingent or otherwise, of such
         Person (i) to purchase or pay (or advance or supply funds for the
         purchase or payment of) such Indebtedness of such other Person (whether
         arising by virtue of partnership arrangements, or by agreements to
         keep-well, to purchase assets, goods, securities or services (unless
         such purchase arrangements are on arm's-length terms and are entered
         into in the ordinary course of business), to take-or-pay, or to
         maintain financial statement conditions or otherwise) or (ii) entered
         into for purposes of assuring in any other manner the obligee of such
         Indebtedness of the payment thereof or to protect such obligee against
         loss in respect thereof (in whole or in part); PROVIDED that the term
         "GUARANTEE" shall not include endorsements for collection or deposit in
         the ordinary course of business. The term "GUARANTEE" used as a verb
         has a corresponding meaning.

                  "HAZARDOUS MATERIALS" means (a) petroleum and petroleum
         products, byproducts or breakdown products, radioactive materials,
         asbestos-containing materials, polychlorinated biphenyls and radon gas
         and (b) any other chemicals, materials or substances designated,
         classified or regulated as hazardous or toxic or as a pollutant or
         contaminant under any Environmental Law.

                  "HEDGE AGREEMENTS" means interest rate swap, cap or collar
         agreements, interest rate future or option contracts, currency swap
         agreements, currency future or option contracts and other similar
         agreements.

                  "HIGH YIELD NOTES" means the 13 1/4% Senior Euro Notes of the
         Parent due 2009 in the amount of Euro 85 million and the 13 1/4% Senior
         Dollar Notes of the Parent due 2009 in the amount of $160 million.

                  "INCUR" means, with respect to any Indebtedness, to incur,
         create, issue, assume, Guarantee or otherwise become liable for or with
         respect to, or become responsible for, the payment of, contingently or
         otherwise, such Indebtedness, including an "INCURRENCE" by means of the
         acquisition of more than 50% of the Capital Stock of any Person;
         PROVIDED that neither the accrual of interest nor the accretion of
         original issue discount shall be considered an Incurrence of
         Indebtedness.


<PAGE>
                                       12


                  "INDEBTEDNESS"  means,  with  respect  to any  Person  at any
         date of  determination  (without duplication):

                           (i)    all indebtedness of such Person for borrowed
                  money;

                           (ii)   all obligations of such Person evidenced by
                  bonds, debentures, notes or other similar instruments;

                           (iii)  all reimbursement obligations of such Person
                  in respect of letters of credit or other similar instruments
                  (excluding obligations with respect to letters of credit
                  (including trade letters of credit) or other similar
                  instruments securing obligations (other than obligations
                  described in (i) or (ii) above or (v), (vi) or (vii) below)
                  entered into in the ordinary course of business of such Person
                  to the extent such letters of credit are not properly honored
                  and drawn upon or, if properly honored and drawn upon, to the
                  extent such drawing is reimbursed no later than the third
                  Business Day following receipt by such Person of a demand for
                  reimbursement);

                           (iv)   all obligations of such Person to pay the
                  deferred and unpaid purchase price of property or services,
                  which purchase price is due more than six months after the
                  date of placing such property in service or taking delivery
                  and title thereto or the completion of such services, except
                  Trade Payables;

                           (v)    all Capitalized Lease Obligations of such
                  Person;

                           (vi)   all Indebtedness of other Persons secured by a
                  Lien on any asset of such Person, whether or not such
                  Indebtedness is assumed by such Person; PROVIDED that the
                  amount of such Indebtedness of such Person shall be the lesser
                  of (A) the fair market value of such asset at such date of
                  determination and (B) the amount of such Indebtedness of such
                  other Persons;

                           (vii)  all Indebtedness of other Persons Guaranteed
                  by such Person; PROVIDED that the amount of Indebtedness of
                  such Person shall be the lesser of (A) the amount Guaranteed
                  and (B) the amount of such Indebtedness of such other Persons;
                  and

                           (viii) to the extent not otherwise included in this
                  definition, obligations under Hedge Agreements except if such
                  agreements (a) are designed solely to protect the Parent or
                  its Restricted Subsidiaries against fluctuations in foreign
                  currency exchange rates or interest rates and (b) do not
                  increase the Indebtedness of the obligor outstanding at any
                  time other than as a result of fluctuations in foreign
                  currency exchange rates or interest rates or by reason of
                  fees, indemnities and compensation payable thereunder;

         PROVIDED, that the amount of Indebtedness of any Person as described
         above at any date shall be the outstanding balance at such date of all
         unconditional obligations as described


<PAGE>
                                       13


         above and, with respect to contingent obligations as described above,
         the maximum liability upon the occurrence of the contingency giving
         rise to the obligation, PROVIDED, FURTHER (A) that the amount
         outstanding at any time of any Indebtedness issued with original issue
         discount is the face amount of such Indebtedness less the remaining
         unamortized portion of the original issue discount of such
         Indebtedness at the time of its issuance as determined in conformity
         with GAAP, (B) that obligations for money borrowed and set aside at
         the time of the Incurrence of any Indebtedness in order to prefund the
         payment of the interest on such Indebtedness shall not be deemed to be
         "INDEBTEDNESS" so long as such money is held to secure the payment of
         such interest, (C) that the amount of an obligation in respect of a
         letter of credit or other similar instrument is the aggregate undrawn
         and unexpired amount thereof plus the aggregate amount of drawings
         properly honored thereunder that have not then been reimbursed, and
         (D) that Indebtedness shall not include any liability for federal,
         state, local or other taxes. Indebtedness shall not be deemed to
         include any obligation arising from the honoring of a check, draft or
         similar instrument drawn against insufficient funds, PROVIDED that
         such obligation is extinguished within five business days of its
         Incurrence.

                   "INDENTURES" means the trust indentures each dated February
         19, 1999 in respect of the High Yield Notes.

                  "INTEREST PERIOD" means, for each Advance comprising part of
         the same Borrowing, the period commencing on the date of such Advance
         and ending on the last day of the period selected by the Parent on
         behalf of the applicable Borrower pursuant to the provisions below and,
         thereafter, each subsequent period commencing on the last day of the
         immediately preceding Interest Period and ending on the last day of the
         period selected by the Parent on behalf of the applicable Borrower
         pursuant to the provisions below. The duration of each such Interest
         Period shall be one or three months, as the Parent on behalf of the
         applicable Borrower may, upon notice received by the Administrative
         Agent not later than 10:00 A.M. (London time) on the third Business Day
         prior to the first day of such Interest Period, select; PROVIDED,
         HOWEVER, that:

                           (i)   the Parent may not select any  Interest
                  Period that ends after the Maturity Date;

                           (ii)  Interest Periods commencing on the same date
                  for Advances comprising part of the same Borrowing shall be of
                  the same duration;

                           (iii) whenever the last day of any Interest Period
                  would otherwise occur on a day other than a Business Day, the
                  last day of such Interest Period shall be extended to occur on
                  the next succeeding Business Day, PROVIDED, HOWEVER, that, if
                  such extension would cause the last day of such Interest
                  Period to occur in the next following calendar month, the last
                  day of such Interest Period shall occur on the next preceding
                  Business Day; and

                           (iv)  whenever the first day of any Interest Period
                  occurs on a day of an initial calendar month for which there
                  is no numerically corresponding day in the


<PAGE>
                                       14


                  calendar month that succeeds such initial calendar month by
                  the number of months equal to the number of months in such
                  Interest Period, such Interest Period shall end on the last
                  Business Day of such succeeding calendar month.

                  "INTERNAL REVENUE CODE" means the Internal Revenue Code of
         1986, as amended from time to time, and the regulations promulgated and
         rulings issued thereunder.

                  "INVESTMENT" in any Person means any direct or indirect
         advance, loan or other extension of credit (including, without
         limitation, by way of Guarantee or similar arrangement; but excluding
         advances, loans or other extensions of credit to customers or suppliers
         in the ordinary course of business to the extent required by GAAP to be
         recorded as accounts receivable, prepaid expenses or deposits on the
         balance sheet of the Parent or its Restricted Subsidiaries) or capital
         contribution to (by means of transfer of cash or other property to
         others or any payment for property or services for the account or use
         of others), or any purchase or acquisition of Capital Stock, bonds,
         notes, debentures or other similar instruments issued by, such Person
         and shall include (i) the designation of a Restricted Subsidiary as an
         Unrestricted Subsidiary and (ii) the fair market value of the Capital
         Stock (or any other Investment), held by the Parent or any of its
         Restricted Subsidiaries, of (or in) any Person that has ceased to be a
         Restricted Subsidiary, including without limitation, by reason of any
         transaction permitted by Section 5.02(d)(iii); PROVIDED that the fair
         market value of the Investment remaining in any Person that has ceased
         to be a Restricted Subsidiary shall not exceed the aggregate amount of
         Investments previously made in such Person valued at the time such
         Investments were made less the net reduction of such Investments. For
         purposes of the definition of "UNRESTRICTED SUBSIDIARY" and Section
         5.02(b), (i) "INVESTMENT" shall include the fair market value of the
         assets (net of liabilities (other than liabilities to the Parent or any
         of its Restricted Subsidiaries)) of any Restricted Subsidiary at the
         time that such Restricted Subsidiary is designated an Unrestricted
         Subsidiary, (ii) the fair market value of the assets (net of
         liabilities (other than liabilities to the Parent or any of its
         Restricted Subsidiaries)) of any Unrestricted Subsidiary at the time
         that such Unrestricted Subsidiary is designated a Restricted Subsidiary
         shall be considered a reduction in outstanding Investments and (iii)
         any property transferred to or from an Unrestricted Subsidiary shall be
         valued at its fair market value at the time of such transfer.

                  "LENDERS" means the Initial Lenders and each Person that shall
         become a party hereto pursuant to Section 9.07.

                  "LIBOR" means for any Interest Period for each Advance
         denominated in Dollars, an interest rate per annum equal to the rate
         per annum appearing on Telerate Page 3750 (or any successor page) as
         the London interbank offered rate for deposits in Dollars, at 11:00
         A.M. (London time) two Business Days before the first day of such
         Interest Period in an amount equal to such Advance and for a period
         equal to (as nearly as practicable) such Interest Period; PROVIDED,
         that, if for any reason such rate is not available, the term "LIBOR"
         shall mean the rates per annum appearing on the Reuters Screen ISDA
         Page (or any successor page) as the London interbank offered rate
         for deposits in Dollars, at 11:00 A.M. (London time) two Business
         Days before the first day of such Interest Period in an

<PAGE>
                                       15


         amount equal to such Advance and for a period equal to (as nearly as
         practicable) such Interest Period; PROVIDED, FURTHER, that if for
         any reason such rate is not available, the term "LIBOR" shall mean
         the average of the sales at which deposits in Dollars are offered by
         the Reference Banks at approximately 11:00 a.m. London time on such
         date to prime banks in the London interbank market.

                  "LIEN" means any mortgage, pledge, security interest,
         encumbrance, lien or charge of any kind (including, without limitation,
         any conditional sale or other title retention agreement or lease in the
         nature thereof or any agreement to give any security interest).

                  "LOAN DOCUMENTS" means this Agreement and, to the extent
         delivered to the Administrative Agent or the Security Agent, as the
         case may be, pursuant to Section 3.02 hereof, the Pledge Agreements, in
         each case as amended or otherwise modified from time to time.

                  "LOAN PARTIES" means the Parent, the Borrowers, and the
         Guarantors.

                  "MANAGEMENT INVESTOR" means any officer, director, employee or
         other member of the management of the Parent or any of its
         Subsidiaries, or family members or relatives thereof, or trusts or
         partnerships for the benefit of any of the foregoing, or any of their
         heirs, executors, successors and legal representatives.

                  "MATERIAL ADVERSE CHANGE" means any material adverse change,
         or any development that would reasonably be expected to cause a
         material adverse change, in the business, financial condition or
         results of operations of the Parent and its Subsidiaries taken as a
         whole.

                  "MATERIAL ADVERSE EFFECT" means a material adverse effect on
         (a) the business, financial condition or results of operations of the
         Parent and its Subsidiaries, taken as a whole, (b) the rights and
         remedies of the Administrative Agent, the Security Agent and the
         Lenders under the Loan Documents or (c) the ability of any Loan Party
         to perform its material obligations under the Loan Documents.

                  "MATURITY DATE" means December 20, 2000.

                  "MOODY'S" means Moody's Investors Service, Inc. and its
         successors.

                  "MULTIEMPLOYER PLAN" means a multiemployer plan, as defined in
         Section 4001(a)(3) of ERISA, to which the Parent or any ERISA Affiliate
         is making or accruing an obligation to make contributions, or has
         within any of the preceding five plan years made or accrued an
         obligation to make contributions.

                  "MULTIPLE EMPLOYER PLAN" means a single employer plan, as
         defined in Section 4001(a)(15) of ERISA, that (a) is maintained for
         employees of the Parent or any ERISA Affiliate and at least one Person
         other than the Parent and the ERISA Affiliates or (b) was so maintained
         and in respect of which the Parent or any ERISA Affiliate could


<PAGE>
                                       16


         reasonably be expected to have liability under Section 4064 or 4069 of
         ERISA in the event such plan has been or were to be terminated.

                  "NET CASH PROCEEDS" means, (a) with respect to any Asset Sale,
         the proceeds of such Asset Sale when received in the form of cash or
         cash equivalents, including payments in respect of deferred payment
         obligations (to the extent corresponding to the principal, but not
         interest, component thereof) when received in the form of cash or cash
         equivalents (except to the extent such obligations are financed or sold
         with recourse to the Parent or any Restricted Subsidiary) and proceeds
         from the conversion of other property received when converted to cash
         or cash equivalents, net of (i) brokerage commissions and other fees
         and expenses (including fees and expenses of counsel and investment
         bankers) related to such Asset Sale, (ii) provisions for all taxes
         (whether or not such taxes will actually be paid or are payable) as a
         result of such Asset Sale without regard to the consolidated results of
         operations of the Parent and its Restricted Subsidiaries, taken as a
         whole, including as a consequence of any transfer of funds in
         connection with the application thereof in accordance with Section
         5.02(i) hereof, (iii) payments made to repay Indebtedness or any other
         obligation outstanding at the time of such Asset Sale that either (A)
         is secured by a Lien on the property or assets sold or (B) is required
         to be paid as a result of such Asset Sale (other than Indebtedness
         under the High Yield Notes), (iv) all distributions and other payments
         required to be made to minority interest holders in a Restricted
         Subsidiary or joint venture as a result of such Asset Sale by or of
         such Restricted Subsidiary or joint venture, or to any other Person
         (other than the Parent or a Restricted Subsidiary) owning a beneficial
         interest in the assets disposed of in such Asset Sale, and (v)
         appropriate amounts to be provided by the Parent or any Restricted
         Subsidiary as a reserve against any liabilities or obligations
         associated with such Asset Sale, including, without limitation, pension
         and other post-employment benefit liabilities, liabilities related to
         environmental matters and liabilities under any indemnification
         obligations associated with such Asset Sale, all as determined in
         conformity with GAAP and (b) with respect to any issuance or sale of
         Capital Stock, the proceeds of such issuance or sale in the form of
         cash or cash equivalents, including payments in respect of deferred
         payment obligations (to the extent corresponding to the principal, but
         not interest, component thereof) when received in the form of cash or
         cash equivalents (except to the extent such obligations are financed or
         sold with recourse to the Parent or any Restricted Subsidiary) and
         proceeds from the conversion of other property received when converted
         to cash or cash equivalents, net of attorney's fees, accountants' fees,
         underwriters' or placement agents' fees, discounts or commissions and
         brokerage, consultant and other fees incurred in connection with such
         issuance or sale and net of taxes paid or payable as a result thereof.
         In the event that any consideration for any Asset Sale that would
         otherwise constitute Net Cash Proceeds is required to be held in escrow
         pending determination of whether a purchase price adjustment,
         indemnification or other payment or similar adjustment will be made,
         such consideration will become Net Cash Proceeds only when and to the
         extent released from escrow to the Parent or a Restricted Subsidiary.

                  "NETWORK FINANCING BORROWINGS" means Indebtedness (including
         Guarantees and the German Network L/C) to finance or refinance the cost
         (including the cost of design, development, acquisition, construction,
         installation, improvement, transportation or


<PAGE>
                                       17


         integration) of acquiring Telecommunications Equipment (including
         acquisitions by way of Capitalized Lease and acquisitions of the
         Capital Stock of a Person that becomes a Restricted Subsidiary to the
         extent of the fair market value of the equipment, inventory or network
         assets so acquired) by the Parent or a Restricted Subsidiary.

                  "NORTEL FACILITY" means the vendor financing facility provided
         by Nortel Networks plc to the Parent in the amount of $75 million under
         a loan agreement dated June 25, 1999.

                  "NOTICE OF BORROWING" has the meaning specified in Section
         2.02 hereof.

                  "OBLIGORS" means the Borrowers and the Guarantors and in any
         event does not include the Parent.

                  "PARTICIPATING MEMBER STATE" means each state so described in
         any legislative measure of the European Council for introduction of,
         changeover to, or operation of the Euro.

                  "PERMITTED CURRENCY" means Euros and Dollars.

                  "PERMITTED HOLDER" means any of the following: any of
         Providence Equity Partners L.P., Providence Equity Partners II L.P.,
         Providence Equity Partners III L.P., Primus Capital Fund IV Limited
         Partnership and Primus Executive Fund Limited Partnership and any of
         the respective Affiliates or successors of the foregoing.

                  "PERMITTED INTERCOMPANY INDEBTEDNESS" means Indebtedness owed
         to the Parent by a Restricted Subsidiary that is (i) subordinated to
         the Advances on terms and conditions reasonably satisfactory to the
         Required Lenders (including on terms that prohibit cash payments in
         respect thereof other than to the extent such payments are applied to
         meet obligations of the Parent referred to in Section 5.04 hereof) or
         (ii) in the case of any such Indebtedness that is outstanding on the
         date hereof, such Indebtedness, PROVIDED, that no later than April 30,
         2000, such Indebtedness is subordinated to the Advances on the terms
         referred to in clause (i) hereof if such subordination can be effected
         without significant adverse tax, accounting or legal consequences to
         the Parent or any Subsidiary.

                  "PERMITTED INVESTMENT" means:

                           (i)    an Investment in the Parent (other than
                  Capital Stock and the High Yield Notes) or a Restricted
                  Subsidiary or a Person which will, upon the making of such
                  Investment, become a Restricted Subsidiary or be merged or
                  consolidated with or into, or transfer or convey all or
                  substantially all its assets to, the Parent or a Restricted
                  Subsidiary; PROVIDED that such Person's primary business is
                  related, ancillary or complementary to the businesses of the
                  Parent and its Restricted Subsidiaries on the date of such
                  Investment;

                           (ii)   Temporary Cash Investments;


<PAGE>
                                       18


                           (iii)  commissions, payroll, travel and similar
                  advances to cover matters that are expected at the time of
                  such advances ultimately to be treated as expenses in
                  accordance with GAAP;

                           (iv)   stock, obligations, securities or other
                  Investments received (a) in satisfaction of judgments or (b)
                  in settlement of debts, or as a result of foreclosure,
                  perfection or enforcement of any Lien, in each case under this
                  clause (b) arising in the ordinary course of business and not
                  in contemplation of the acquisition of such stock,
                  obligations, securities or other Investments;

                           (v)    Investments in negotiable instruments held for
                  collection, lease, utility and worker's compensation,
                  performance and other similar pledges or deposits and other
                  pledges or deposits permitted under Section 5.02(g) hereof;

                           (vi)   obligations under Hedge Agreements designed
                  solely to protect the Parent or its Restricted Subsidiaries
                  against fluctuations in interest rates or foreign currency
                  exchange rates;

                           (vii)  Investments in a joint venture to cover the
                  Parent's portion of the cost (including the cost of design,
                  development, acquisition, construction, installation and
                  improvement) of building a telecommunications network (or
                  network segment) in Europe, PROVIDED that the Parent or any of
                  its Restricted Subsidiaries will directly own their portion of
                  such network (or network segment); and Investments in joint
                  ventures to acquire or maintain or otherwise relating to any
                  rights-of-way, wayleaves, governmental approvals, licenses,
                  franchises or concessions relating to any such network (or
                  network segment);

                           (viii) Investments in any Person in an aggregate
                  amount not to exceed 25% of any gains (net of any losses)
                  attributable to Asset Sales after the Closing Date and prior
                  to the date of such Investment; and

                           (ix)   loans or advances to directors, officers or
                  employees of the Parent or any Restricted Subsidiary that do
                  not in the aggregate exceed $3 million at any time
                  outstanding.

                  "PERMITTED JOINT VENTURE" means any joint venture between the
         Parent or any Restricted Subsidiary and any Person other than a
         Subsidiary, engaged in the provision or sale of telecommunications
         services, or in any other business that is related, ancillary or
         complementary to the provision or sale of telecommunications services,
         as determined in good faith by the Board of Directors (whose
         determination shall be conclusive if evidenced by a Board Resolution);
         PROVIDED that prior to making any Investment in such a Person, the
         Parent's Board of Directors shall have determined that such Investment
         fits the Parent's strategic plan and is on terms that are fair and
         reasonable to the Parent.

                  "PERMITTED LIENS" means:


<PAGE>
                                       19


                           (i)     Liens for taxes, assessments, governmental
                  charges or claims not yet delinquent, or that in the aggregate
                  are not material, or that are being contested in good faith by
                  appropriate proceedings promptly instituted and diligently
                  conducted and for which a reserve or other appropriate
                  provision, if any, as shall be required in conformity with
                  GAAP shall have been made;

                           (ii)    statutory and common law Liens of landlords,
                  carriers, warehousemen, mechanics, suppliers, materialmen,
                  repairmen or other similar Liens arising in the ordinary
                  course of business and with respect to amounts not yet
                  delinquent or that have been bonded or that are being
                  contested in good faith by appropriate proceedings promptly
                  instituted and diligently conducted and for which a reserve or
                  other appropriate provision, if any, as shall be required in
                  conformity with GAAP shall have been made;

                           (iii)   Liens incurred or deposits made in the
                  ordinary course of business in connection with workers'
                  compensation, unemployment insurance and other types of
                  social security and other similar legislation or other
                  insurance-related obligations (including, without
                  limitation, pledges or deposits securing liability to
                  insurance carriers under insurance or self-insurance
                  arrangements);

                           (iv)    Liens incurred or deposits made to secure the
                  performance of tenders, bids, leases, licenses, obligations
                  for utilities, statutory or regulatory obligations, bankers'
                  acceptances, letters of credit, surety and appeal bonds,
                  government or other contracts, completion guarantees,
                  performance and return-of-money bonds and other obligations of
                  a similar nature incurred in the ordinary course of business
                  (exclusive of obligations for the payment of borrowed money);

                           (v)     easements, rights-of-way, municipal and
                  zoning ordinances, utility agreements, reservations,
                  encroachments, restrictions and similar charges, encumbrances,
                  title defects or other irregularities that do not materially
                  interfere with the ordinary course of business of the Parent
                  or any of its Restricted Subsidiaries;

                           (vi)    Liens (including extensions, renewals and
                  replacements thereof) upon real or personal property or assets
                  (including leases on an indefeasible right-to-use basis);
                  PROVIDED that (a) such Lien is created solely for the purpose
                  of securing Indebtedness Incurred, in accordance with Section
                  5.02(a), to finance or refinance the cost (including the cost
                  of design, development, acquisition, construction,
                  installation, improvement, transportation or integration) of
                  the item of property or assets subject thereto and the
                  original such Lien is created prior to, at the time of or
                  within one year after the later of the acquisition, the
                  completion of construction or the commencement of full
                  operation of such property or assets, (b) the principal amount
                  of the Indebtedness secured by such Lien does not exceed 100%
                  of such cost and (c) any such Lien shall not extend to or
                  cover any property


<PAGE>
                                       20


                  or assets other than such item of property or assets and any
                  improvements, accessions or proceeds in respect of such item;

                           (vii)   leases, subleases, licenses or sublicenses
                  granted to others that do not materially interfere with the
                  ordinary course of business of the Parent and its Restricted
                  Subsidiaries, taken as a whole;

                           (viii)  Liens encumbering property or assets under
                  construction (and related rights) in favor of a contractor or
                  developer, or arising from progress or partial payments by a
                  customer of the Parent or its Restricted Subsidiaries relating
                  to such property or assets;

                           (ix)    any interest or title of a lessor in the
                  property subject to any Capitalized Lease or operating lease;

                           (x)     Liens arising from filing Uniform Commercial
                  Code financing statements regarding leases;

                           (xi)    Liens (including extensions, renewals and
                  replacements thereof) on property or assets of, or on shares
                  of Capital Stock or Indebtedness of, any Person existing (in
                  the case of the original such Lien) at the time such Person
                  becomes, or becomes a part of, any Restricted Subsidiary;
                  PROVIDED that such Liens do not extend to or cover any
                  property or assets of the Parent or any Restricted Subsidiary
                  other than the property, assets, Capital Stock or Indebtedness
                  so acquired (plus improvements, accessions or proceeds
                  (including dividends or distributions) in respect thereof);

                           (xii)    Liens in favor of the Parent  arising by
                  operation of law or in favor of any Restricted Subsidiary;

                           (xiii)  Liens arising from the rendering of a final
                  judgment, order, decree or award against the Parent or any
                  Restricted Subsidiary that does not give rise to an Event of
                  Default;

                           (xiv)   Liens securing reimbursement obligations with
                  respect to letters of credit that encumber documents and other
                  property relating to such letters of credit and the products
                  and proceeds thereof;

                           (xv)    Liens in favor of customs and revenue
                  authorities arising as a matter of law to secure payment of
                  customs duties in connection with the importation of goods;

                           (xvi)   Liens encumbering customary initial deposits
                  and margin deposits, and other Liens that are within the
                  general parameters customary in the industry and incurred in
                  the ordinary course of business, in each case, securing
                  Indebtedness or other obligations under Hedge Agreements and
                  forward contracts,


<PAGE>
                                       21


                  options, future contracts, futures options or similar
                  agreements or arrangements designed solely to protect the
                  Parent or any of its Restricted Subsidiaries from
                  fluctuations in interest rates, currencies or the price of
                  commodities;

                           (xvii)  Liens arising out of conditional sale, title
                  retention, consignment or similar arrangements for the sale of
                  goods entered into by the Parent or any of its Restricted
                  Subsidiaries in the ordinary course of business;

                           (xviii) [Intentionally omitted];

                           (xix)   Liens that secure Indebtedness or other
                  obligations with an aggregate principal amount not in excess
                  of $5 million at any time outstanding;

                           (xx)    Liens placed by any third party on property
                  over which the Parent or any Restricted Subsidiary has
                  easement or other rights or on any leased property, or
                  arising by reason of subordination or similar agreements
                  relating thereto; and Liens arising by reason of any
                  condemnation or eminent domain proceedings;

                           (xxi)   Liens on Capital Stock or other securities of
                  an Unrestricted Subsidiary that secure Indebtedness or other
                  obligations of such Unrestricted Subsidiary;

                           (xxii)  any encumbrance or restriction (including,
                  but not limited to, put and call agreements) with respect to
                  Capital Stock of any joint venture or similar arrangement
                  pursuant to any joint venture or similar agreement;

                           (xxiii) Liens (including extensions, renewals and
                  replacements thereof) on property or assets acquired by the
                  Parent or any Restricted Subsidiary; PROVIDED that (a) such
                  Liens were not created in connection with or in anticipation
                  of such acquisition, (b) such Liens do not secure Indebtedness
                  other than Indebtedness assumed in connection with such
                  acquisition and (c) such Liens do not extend to or cover any
                  property or assets of the Parent or any Restricted Subsidiary
                  other than the property or assets so acquired (plus
                  improvements, accessions or proceeds in respect thereof); and

                           (xxiv)  Liens on cash set aside at the time of the
                  Incurrence of any Indebtedness (including without limitation
                  the High Yield Notes), or government securities purchased with
                  such cash, in either case to the extent that such cash or
                  government securities prefund the payment of interest on such
                  Indebtedness and are held in an escrow account or similar
                  arrangement to be applied for such purpose.

                  "PERSON" means an individual, partnership, corporation
         (including a businesstrust), joint stock company, trust, unincorporated
         association, joint venture, limited

<PAGE>




                                       22



liability company or other entity, or a government or any political subdivision
and an agency or instrumentality thereof.

     "PLAN" means a Single Employer Plan or a Multiple Employer Plan.

     "PLEDGE AGREEMENTS" shall mean the German Pledge Agreement, the Swiss
Pledge Agreement, the French Pledge Agreement and the Deed of Charge and any
other pledge agreement pledging the shares of any Acceding Borrower pursuant to
Section 3.03(b) hereof.

     "PLEDGED SHARES" means the shares or other ownership interests of certain
Subsidiaries of the Parent pledged to the Security Agent on behalf of the
Lenders pursuant to the Pledge Agreements.

     "PREFERRED STOCK" means, with respect to any Person, any and all shares,
interests, participations or other equivalents (however designated, whether
voting or non-voting) of such Person's preferred or preference equity, whether
now outstanding or issued after the Closing Date, including, without limitation,
all series and classes of such preferred stock or preference stock.

     "QUALIFYING BANK" means a Lender that is (i) either a Person that is
entitled to receive payments hereunder (other than payments pursuant to Section
9.04 hereof) from a Borrower organized in the United Kingdom free and clear of
and without deduction for or on account of Taxes imposed by the United Kingdom
(or any political subdivision thereof or therein) and without being subject to
such Taxes in each case pursuant to applicable U.K. law or pursuant to an
applicable tax treaty or a Lender that is a bank (x) within the meaning of
Section 840A of the U.K. Income and Corporation Taxes Act 1988 (the "ACT"), (y)
within the charge to U.K. corporation tax for the purposes of Section 349(3) of
the Act in respect of interest payable or paid to it hereunder and (z) resident
in the United Kingdom for U.K. tax purposes (but if the Act is amended or
repealed, this clause (i) shall be amended in such manner as the Administrative
Agent, after consultation with the Parent, shall determine to be necessary in
order to define Persons of relevant equivalent categories) and (ii) a Person
that with respect to each Borrower that is an original signatory to this
Agreement and is organized in a jurisdiction other than the United Kingdom
either (x) has its lending office located in a jurisdiction that is a party to
an applicable tax treaty with the jurisdiction of organization of such Borrower
that reduces the rate of Taxes and withholding on payments hereunder by such
Borrower (other than payments pursuant to Section 9.04 hereof) to zero or (y)
benefits from an exemption from Taxes and withholding on payments hereunder
(other than payments pursuant to Section 9.04 hereof) by such Borrower under the
laws of the jurisdiction in which such Borrower is organized.

     "REFERENCE BANKS" means the principal London offices of Citibank, N.A. and
Morgan Stanley Dean Witter Bank Limited or, if either such bank ceases to be a
Reference Bank, such other bank as the Administrative Agent shall reasonably
select after consultation with the Parent.


<PAGE>
                                       23


     "REGISTER" has the meaning specified in Section 9.07(c).

     "RELEASED INDEBTEDNESS" means, with respect to any Asset Sale, (i)
Indebtedness of the Parent or any Restricted Subsidiary which is assumed by the
purchaser or any affiliate thereof in connection with such Asset Sale; PROVIDED
that the Parent or such Restricted Subsidiary receives written, unconditional,
valid and enforceable releases from each creditor, no later than the closing
date of such Asset Sale and (ii) Indebtedness of a Restricted Subsidiary that is
no longer a Restricted Subsidiary as a result of such Asset Sale; PROVIDED that
neither the Parent nor any other Restricted Subsidiary thereafter Guarantees
such Indebtedness.

      "REQUIRED LENDERS" means at any time Lenders owed at least 51% of the then
aggregate unpaid principal amount of the Advances owing to the Lenders, or, if
no such principal amount is then outstanding, Lenders having at least 51% of the
Commitments.

     "RESTRICTED PERIOD" means the period from December 22, 1999 to and
including January 4, 2000.

     "RESTRICTED SUBSIDIARY" means any Subsidiary of the Parent other than an
Unrestricted Subsidiary.

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

     "SIGNIFICANT SUBSIDIARY" means, at any date of determination, (i) any
Obligor and (ii) any Restricted Subsidiary that, together with its Subsidiaries,
(x) for the most recent fiscal year of the Parent, accounted for more than 10%
of the consolidated revenues of the Parent and its Restricted Subsidiaries or
(y) as of the end of such fiscal year, was the owner of more than 10% of the
consolidated assets of the Parent and its Restricted Subsidiaries, all as set
forth on the most recently available consolidated financial statements of the
Parent for such fiscal year.

     "SINGLE EMPLOYER PLAN" means a single employer plan, as defined in Section
4001(a)(15) of ERISA, that (a) is maintained for employees of the Parent or any
ERISA Affiliate and no Person other than the Parent and the ERISA Affiliates or
(b) was so maintained and in respect of which the Parent or any ERISA Affiliate
would reasonably be expected to have liability under Section 4069 of ERISA in
the event such plan has been or were to be terminated.

     "SOLVENT" and "SOLVENCY" mean, with respect to any Person on a particular
date, that on such date (a) the fair value of the assets of such Person is
greater than the total amount of liabilities, including, without limitation,
contingent liabilities, of such Person, (b) the present fair salable value of
the assets of such Person is not less than the amount that will be required to
pay the probable liability of such Person on its debts as they become absolute
and matured, (c) such Person does not intend to, and does not believe that it
will, incur debts or liabilities beyond such Person's ability to pay such debts
and


<PAGE>
                                       24


liabilities as they mature, (d) such Person is not engaged in business or a
transaction, and is not about to engage in business or a transaction, for which
such Person's property would constitute an unreasonably small capital and (e)
such Person is not (i) in the case of any Person organized under or otherwise
subject to the laws relating to solvency of the Federal Republic of Germany or
Switzerland, overindebted (UBERSCHULDET), illiquid (ZAHLUNGSUNFAHIG) or
threatened with illiquidity (DROHENDE ZAHLUNGSUNFAHIGKEIT) or (ii) in the case
of any other Person, subject to any other similar condition under the laws of
the jurisdiction in which such Person is organized. The amount of contingent
liabilities at any time shall be computed as the amount that, in the light of
all the facts and circumstances existing at such time, represents the amount
that can reasonably be expected to become an actual or matured liability.

     "STATED MATURITY" means, (i) with respect to any debt security, the date
specified in such debt security as the fixed date on which the final installment
of principal of such debt security, is due and payable and (ii) with respect to
any scheduled installment of principal of or interest on any debt security, the
date specified in such debt security as the fixed date on which such installment
is due and payable.

     "STRATEGIC SUBORDINATED INDEBTEDNESS" means Indebtedness of the Parent
Incurred to finance the acquisition of a Person engaged in a business that is
related, ancillary or complementary to the business conducted by the Parent or
any of its Restricted Subsidiaries, which Indebtedness by its terms, or by the
terms of any agreement or instrument pursuant to which such Indebtedness is
Incurred provides that no payment of principal, premium or interest on, or any
other payment with respect to, such Indebtedness may be made prior to the
payment in full of all of the Obligors' obligations under the Loan Documents;
PROVIDED that such Indebtedness may provide for and be repaid at any time from
the proceeds of a capital contribution or the sale of Capital Stock (other than
Disqualified Stock) of the Parent after the Incurrence of such Indebtedness.

     "SUBSIDIARY" of any Person means, with respect to any Person, any
corporation, association, or other business entity of which more than 50% of the
outstanding Voting Stock is owned by such Person and one or more other
Subsidiaries of such Person.

     "SUBSIDIARY GUARANTEE" has the meaning provided in Section 5.02(e).

     "SUBSIDIARY GUARANTOR" means any Restricted Subsidiary who, from time to
time, provides a guarantee pursuant to Section 5.02(e)(i).

     "TELECOMMUNICATIONS EQUIPMENT" means (i) fiber optic cable, data and voice
switches, transmission equipment and other ancillary equipment, fees and costs,
and related tangible assets, (ii) all software and hardware associated with the
network operating center and back office systems (including OSS, billing
systems, and data services), together with all related support and installation
costs associated with an operational system, provided that such costs are
capitalized according to GAAP and (iii) any other equipment, inventory or
network assets (including leases on an indefeasible right-to-use basis and
multiple investment units).


<PAGE>
                                       25


     "TEMPORARY CASH INVESTMENT" means any of the following:

          (i) direct obligations of the United States of America or any agency
     thereof or obligations fully and unconditionally guaranteed by the United
     States of America or any agency thereof;

          (ii) bankers' acceptances, time deposit accounts, certificates of
     deposit and money market deposits maturing within one year of the date of
     acquisition thereof issued by a bank or trust company which is organized
     under the laws of the United States of America, any state thereof or any
     foreign country recognized by the United States of America, and which bank
     or trust company has capital, surplus and undivided profits aggregating in
     excess of $50 million (or the foreign currency equivalent thereof) and has
     outstanding debt which is rated "A" (or such similar equivalent rating) or
     higher by at least one nationally recognized statistical rating
     organization or any money-market fund sponsored by a registered broker
     dealer or mutual fund distributor;

          (iii) repurchase obligations with a term of not more than 30 days for
     underlying securities of the types described in clause (i) above or clause
     (vi) below entered into with a bank meeting the qualifications described in
     clause (ii) above;

          (iv) commercial paper, maturing not more than one year after the date
     of acquisition, issued by a corporation (other than an Affiliate of the
     Parent) organized and in existence under the laws of the United States of
     America, any state thereof or any foreign country recognized by the United
     States of America with a rating at the time as of which any investment
     therein is made of "P-1" (or higher) according to Moody's or "A-1" (or
     higher) according to S&P;

          (v) securities with maturities of six months or less from the date of
     acquisition issued or fully and unconditionally guaranteed by any state,
     commonwealth or territory of the United States of America, or by any
     political subdivision or taxing authority thereof, and rated at least "A"
     by S&P or Moody's; and

          (vi) direct obligations of, or obligations fully and unconditionally
     guaranteed by, (a) The Netherlands, the United Kingdom, France, Germany or
     Switzerland or (b) any other member of the European Economic Community and
     rated at least "A" by S&P or Moody's

     "TERMINATION DATE" means the earlier of November 30, 2000 and the date
of termination in whole of the Commitments pursuant to Section 2.04 or 6.01.

     "TRADE PAYABLES" means, with respect to any Person, any accounts payable or
any other indebtedness or monetary obligation to trade creditors created,
assumed or guaranteed by such Person or any of its Subsidiaries arising in the
ordinary course of business in connection with the acquisition of goods or
services.


<PAGE>
                                       26


     "TRANSACTION DATE" means, with respect to the Incurrence of any
Indebtedness by the Parent or any of its Restricted Subsidiaries, the date such
Indebtedness is to be Incurred and, with respect to any Restricted Payment, the
date such Restricted Payment is to be made.

     "UNRESTRICTED SUBSIDIARY" means (i) any Subsidiary of the Parent that at
the time of determination shall be designated an Unrestricted Subsidiary by the
Board of Directors in the manner provided below and (ii) any Subsidiary of an
Unrestricted Subsidiary. The Board of Directors may designate any Restricted
Subsidiary (including any newly acquired or newly formed Subsidiary of the
Parent) to be an Unrestricted Subsidiary unless such Subsidiary owns any Capital
Stock of, or owns or holds any Lien on any property of, the Parent or any
Restricted Subsidiary; PROVIDED that (A) any Guarantee by the Parent or any
Restricted Subsidiary of any Indebtedness of the Subsidiary being so designated
shall be deemed an "INCURRENCE" of such Indebtedness and an "INVESTMENT" by the
Parent or such Restricted Subsidiary (or both, if applicable) at the time of
such designation; (B) either (I) the Subsidiary to be so designated has total
assets of $1,000 or less or (II) if such Subsidiary has assets greater than
$1,000, such designation would be permitted under Section 5.02(b) hereof and (C)
if applicable, the Incurrence of Indebtedness and the Investment referred to in
clause (A) of this proviso would be permitted under Section 5.02(a) and Section
5.02(b) hereof. The Board of Directors may designate any Unrestricted Subsidiary
to be a Restricted Subsidiary; PROVIDED that (i) no Default or Event of Default
shall have occurred and be continuing at the time of or after giving effect to
such designation and (ii) all Liens and Indebtedness of such Unrestricted
Subsidiary outstanding immediately after such designation would, if Incurred at
such time, have been permitted to be Incurred (and shall be deemed to have been
Incurred) for all purposes of this Agreement. Any such designation by the Board
of Directors shall be evidenced to the Administrative Agent by promptly filing
with the Administrative Agent a copy of the Board Resolution giving effect to
such designation and an officers' certificate certifying that such designation
complied with the foregoing provisions.

     "VAT" or "VALUE ADDED TAX" means value added tax chargeable in the United
Kingdom under the Value Added Tax Act 1994 or any similar tax imposed in another
jurisdiction.

     "VOTING STOCK" means, with respect to any Person, Capital Stock of any
class or kind ordinarily having the power to vote for the election of directors,
managers or other voting members of the governing body of such Person.

     "WARRANT AGREEMENTS" has the meaning given to it in the Indentures.

     "WARRANTS" has the meaning given to it in the Indentures.

     "WHOLLY OWNED" means, with respect to any Subsidiary of any Person, the
ownership of all of the outstanding Capital Stock of such Subsidiary (other than
any director's qualifying shares or Investments by foreign nationals mandated by
applicable law) by such Person or one or more Wholly Owned Subsidiaries of such
Person.


<PAGE>
                                       27



     SECTION 1.02. OTHER DEFINED TERMS. The following terms shall have the
meanings specified in the sections set forth below:

<TABLE>
<CAPTION>

     Term                                                 Section
<S>                                                       <C>
     Administrative Agent                                 Preamble
     Borrowers                                            Preamble
     Deed of Charge                                       3.02(a)(iii)
     French Pledge Agreement                              3.02(a)(i)
     German Pledge Agreement                              3.02(a)(iv)
     Guaranteed Obligations                               8.01(a)
     Guarantors                                           Preamble
     HGB                                                  8.01(b)
     Indemnified Costs                                    7.05
     Indemnified Party                                    9.04(b)
     Information                                          3.01(e)
     Initial Lenders                                      Preamble
     Lead Arrangers                                       Preamble
     MSSF                                                 Preamble
     Other Taxes                                          2.12(b)
     Parent                                               Preamble
     Primary Currency                                     9.11(c)
     Projections                                          4.01(r)
     Restricted Payment                                   5.02(b)
     Security Agent                                       Preamble
     Taxes                                                2.12(a)
     Swiss Pledge Agreement                               3.02(a)(ii)

</TABLE>


     SECTION 1.03. COMPUTATION OF TIME PERIODS. In this Agreement in the
computation of periods of time from a specified date to a later specified date,
the word "from" means "from and including" and the words "to" and "until" each
mean "to but excluding".

     SECTION 1.04. ACCOUNTING TERMS. All accounting terms not specifically
defined herein shall be construed in accordance with GAAP.

                                   ARTICLE II

                        AMOUNTS AND TERMS OF THE ADVANCES

<PAGE>
                                       28



     SECTION 2.01. THE ADVANCES. Each Lender severally agrees, on the terms and
conditions hereinafter set forth, to make Advances in either Permitted Currency
to the Borrowers from time to time on any Business Day during the period from
the Closing Date until the Termination Date in an aggregate amount not to exceed
at any time outstanding the amount set forth opposite such Lender's name on
Schedule 1 hereto or, if such Lender has entered into any Assignment and
Acceptance, set forth for such Lender in the Register maintained by the
Administrative Agent pursuant to Section 9.07(c), as such amount may be reduced
pursuant to Section 2.04 or Section 2.08(c) hereof (such Lender's "COMMITMENT");
PROVIDED, HOWEVER, that the aggregate amount of Advances made under this Section
2.01 shall not exceed $25 million (or the Euro Equivalent thereof) until the
conditions precedent specified in Section 3.02 hereof shall have been satisfied;
PROVIDED, FURTHER, that so long as the High Yield Notes remain outstanding and
except for Advances made for the purpose of Network Financing Borrowings, the
aggregate amount of Advances made under this Section 2.01 shall not exceed $100
million (or the Euro Equivalent thereof) plus 80% of the Consolidated book value
of the accounts receivable of the Parent and its Restricted Subsidiaries
determined in accordance with GAAP; PROVIDED, FURTHER, that no Borrowing may be
made during the Restricted Period unless each of the Initial Lenders in its sole
discretion consents. Each Borrowing shall be in an aggregate amount of (i) $5
million (or in the case of Borrowings denominated in Euros, Euro 5 million) or
an integral multiple of $500,000 (or in the case of Borrowings denominated in
Euros, Euro 500,000) in excess thereof or (ii) the entire amount of the undrawn
Commitments of the Lenders, and shall consist of Advances made on the same day
in the same Permitted Currency by the Lenders ratably according to their
respective Commitments. Amounts borrowed under this Section 2.01 and repaid or
prepaid may not be reborrowed.

     SECTION 2.02. MAKING THE ADVANCES. (a) Except for the initial Borrowing
made on the Closing Date, each Borrowing shall be made on notice, given not
later than 10:00 A.M. (London time) on the third Business Day prior to the date
of the proposed Borrowing by the Parent on behalf of the applicable Borrower to
the Administrative Agent, which shall give to each Lender prompt notice thereof
by telecopier. Each such notice of a Borrowing (a "NOTICE OF BORROWING") shall
be by telephone, confirmed immediately in writing, or telecopier, in
substantially the form of Exhibit B hereto, specifying therein the requested (i)
date of such Borrowing, (ii) aggregate amount of such Borrowing (iii) the
Permitted Currency in which such Borrowing shall be made and (iv) initial
Interest Period for each such Borrowing. Each Lender shall, before 11:00 A.M.
(London time) on the date of such Borrowing, make available to the
Administrative Agent at the Administrative Agent's Account, in same day funds,
such Lender's ratable portion of such Borrowing. After the Administrative
Agent's receipt of such funds and upon fulfillment of the applicable conditions
set forth in Article III, the Administrative Agent will make such funds
available to the applicable Borrower at the Administrative Agent's address
referred to in Section 9.02.

         (b) Anything in subsection (a) above to the contrary notwithstanding,
the Advances may not be outstanding as part of more than 7 separate Borrowings.

         (c) Each Notice of Borrowing shall be irrevocable and binding on the
applicable Borrower. The Parent shall indemnify each Lender against any loss,
cost or expense incurred by such Lender as a result of any failure to fulfill on
or before the date specified in such Notice of



<PAGE>
                                       29


Borrowing for such Borrowing the applicable conditions set forth in Article III,
including, without limitation, any loss (including loss of anticipated profits),
cost or expense actually incurred by reason of the liquidation or reemployment
of deposits or other funds acquired by such Lender to fund the Advance to be
made by such Lender as part of such Borrowing when such Advance, as a result of
such failure, is not made on such date.

        (d) Unless the Administrative Agent shall have received notice from a
Lender prior to the date of any Borrowing that such Lender will not make
available to the Administrative Agent such Lender's ratable portion of such
Borrowing, the Administrative Agent may assume that such Lender has made such
portion available to the Administrative Agent on the date of such Borrowing in
accordance with subsection (a) of this Section 2.02 and the Administrative Agent
may, in reliance upon such assumption, make available to the applicable Borrower
on such date a corresponding amount. If and to the extent that such Lender shall
not have so made such ratable portion available to the Administrative Agent,
such Lender and the applicable Borrower severally agree to repay to the
Administrative Agent forthwith on demand such corresponding amount together with
interest thereon, for each day from the date such amount is made available to
such Borrower until the date such amount is repaid to the Administrative Agent,
at (i) in the case of such applicable Borrower, the interest rate applicable at
the time to Advances comprising such Borrowing and (ii) in the case of such
Lender, at a rate specified by the Administrative Agent to be its cost of funds.
If such Lender shall repay to the Administrative Agent such corresponding
amount, such amount so repaid shall constitute such Lender's Advance as part of
such Borrowing for purposes of this Agreement.

         (e) The failure of any Lender to make the Advance to be made by it as
part of any Borrowing shall not relieve any other Lender of its obligation, if
any, hereunder to make its Advance on the date of such Borrowing, but no Lender
shall be responsible for the failure of any other Lender to make the Advance to
be made by such other Lender on the date of any Borrowing.

     SECTION 2.03. FEES. (a) COMMITMENT FEE. The Parent agrees on behalf of the
Borrowers to pay, or cause the Borrowers to pay, to the Administrative Agent for
the account of each Lender a commitment fee on the aggregate amount of such
Lender's Commitment from December 9, 1999 (or such later date as such Initial
Lender issued its commitment) in the case of each Initial Lender and from the
effective date specified in the Assignment and Acceptance pursuant to which it
became a Lender in the case of each other Lender payable in arrears on the
Closing Date and quarterly on the last day of each quarter thereafter, and on
the earlier of (i) the termination in whole of the unused portions of the
Commitments pursuant to Section 2.04 or 2.08 hereof or (ii) the Termination
Date, in each case at the rate of 0.875% per annum on the average daily unused
portion of such Lender's Commitment during such quarter.

         (b) AGENT'S FEES. The Parent shall pay, or cause the Borrowers to pay,
to the Administrative Agent for its own account such fees as have been
separately agreed between the Parent and the Administrative Agent.

     SECTION 2.04. TERMINATION OR REDUCTION OF THE COMMITMENTS. The Parent shall
have the right on behalf of the Borrowers, upon at least one Business Day's
notice to the Administrative Agent, to terminate in whole or reduce ratably in
part the unused portions of the


<PAGE>
                                       30


respective Commitments of the Lenders, PROVIDED that each partial reduction
shall be in the aggregate amount of $5 million or an integral multiple of
$500,000 in excess thereof.

     SECTION 2.05. REPAYMENT. Each Borrower shall repay to the Administrative
Agent for the ratable account of the Lenders on the Maturity Date the aggregate
principal amount of the Advances borrowed by it then outstanding.

     SECTION 2.06. INTEREST. (a) SCHEDULED INTEREST. Each Borrower shall pay
interest on the unpaid principal amount of each Advance borrowed by it owing to
each Lender from the date of such Advance until such principal amount shall be
paid in full at the following rates per annum:

          (i) For each Advance denominated in Dollars, at a rate per annum equal
     at all times during each Interest Period for such Advance to the sum of (x)
     LIBOR PLUS (y) the Applicable Margin in effect from time to time, payable
     in arrears on the last day of such Interest Period and on the date such
     Advance shall be paid in full;

          (ii) For each Advance denominated in Euros, a rate per annum equal at
     all times during each Interest Period for such Advance to the sum of (A)
     Euro LIBOR for such Interest Period for such Advance plus (B) the
     Applicable Margin in effect from time to time, payable in arrears on the
     last day of such Interest Period and on the date such Advance shall be paid
     in full.

         (b) DEFAULT INTEREST. Upon the occurrence and during the continuance of
an Event of Default under Section 6.01(a) or (b) hereof, each Borrower shall pay
interest on (i) the unpaid principal amount of each Advance owing to each
Lender, payable in arrears on the dates referred to in clause (a) above, at a
rate per annum equal at all times to 2% per annum above the rate per annum
required to be paid on such Advance pursuant to clause (a) above and (ii) to the
fullest extent permitted by law, the amount of any interest payable hereunder
that is not paid when due, from the date such amount shall be due until such
amount shall be paid in full, payable in arrears on the date such amount shall
be paid in full and on demand, at a rate per annum equal at all times to 2% per
annum above the rate per annum required to be paid on Advances pursuant to
clause (a) above.

     SECTION 2.07. INTEREST RATE DETERMINATION. (a) The Administrative Agent
shall give prompt notice to the Parent and the Lenders of the applicable
interest rate determined by the Administrative Agent for purposes of Section
2.06(a) hereof.

         (b) If, with respect to any Advances, the Required Lenders notify the
Administrative Agent that the interest rate for any Interest Period for such
Advances will not adequately reflect the cost to such Required Lenders of
making, funding or maintaining their respective Advances for such Interest
Period, the Administrative Agent shall forthwith so notify the Parent and the
Lenders, then (i) within 15 days after any such notice by the Administrative
Agent, the Administrative Agent and the Parent shall enter into negotiations in
good faith with a view to agreeing to an alternative interest rate acceptable to
the Parent to make, fund or maintain such Advances and (ii) if, at the
expiration of 20 days from the giving of such notice by the Administrative
Agent, the Administrative Agent and the Parent shall not have reached an


<PAGE>
                                       31

agreement, such Advances will bear interest at a rate per annum specified by
each such Lender to represent its cost of funds therefor plus the Applicable
Margin.

         (c) If the Parent shall fail to select the duration of any Interest
Period for any Advances in accordance with the provisions contained in the
definition of "Interest Period" in Section 1.01 hereof, the Administrative Agent
will forthwith so notify the Parent and the Lenders and the Interest Period
shall have a duration equal to one month or, if a period of one month would
extend beyond the Maturity Date, an Interest Period that ends on the Maturity
Date.

     SECTION 2.08. PREPAYMENTS. (a) OPTIONAL PREPAYMENTS. Any Borrower may, upon
at least three Business Days' notice to the Administrative Agent stating the
proposed date and aggregate principal amount of the prepayment, and if such
notice is given such Borrower shall, prepay the outstanding principal amount of
the Advances comprising part of the same Borrowing in whole or ratably in part,
together with accrued interest to the date of such prepayment on the principal
amount prepaid; PROVIDED, HOWEVER, that (x) each partial prepayment shall be in
an aggregate principal amount of $5 million in the case of Advances denominated
in Dollars (or Euro 5 million, in the case of Advances denominated in Euros) or
an integral multiple of $500,000 in the case of Advances denominated in Dollars
(or Euro 500,000, in the case of Advances denominated in Euros) in excess
thereof and (y) the applicable Borrower shall be obligated to reimburse the
Lenders in respect thereof pursuant to Section 9.04(c).

         (b) MANDATORY PREPAYMENTS. The Parent shall, on the date of receipt by
the Parent or any of its Subsidiaries of (i) the Net Cash Proceeds from (A) any
Asset Sale or (B) the issuance of additional Indebtedness (other than
Indebtedness permitted by clause (F) of Section 5.02(a)(i)) or equity (excluding
the issuance of Capital Stock to any Management Investor) of the Parent or its
Subsidiaries and (ii) any Extraordinary Receipt received by or paid to or for
the account of any Borrower or any of its Subsidiaries and not included in
clause (i) above, cause one or more Borrowers to prepay an aggregate principal
amount of Advances comprising part of the same Borrowings in an amount equal to
the amount of such Net Cash Proceeds or Extraordinary Receipts, as the case may
be, together with accrued interest to the date of such prepayment on the
principal amount prepaid; PROVIDED that in the event that such Borrower is able
to meet the conditions precedent set forth in Section 3.03 hereof on the date of
such prepayment, such prepayment may, at the election of such Borrower by notice
to the Administrative Agent on the date of such prepayment confirming its
ability to meet such conditions precedent, be made net of any amount that such
Borrower would be entitled to borrow hereunder on the date of such prepayment
(or such lesser amount as may be specified in such notice). In the event that,
as of any Business Day, the aggregate principal amount of the Advances exceeds,
as a result of fluctuations in the exchange rate (determined as provided in the
definition of "Equivalent") of the Euro to the Dollar, 105% of the aggregate
amount of the Commitments as of such Business Day, the Parent shall within three
Business Days cause one or more Borrowers to prepay an aggregate principal
amount of the Advances equal to the difference between the amount of the
Advances as so calculated and the aggregate amount of the Commitments.

         (c) The Commitments of the Lenders shall be reduced ratably by the
amount of any prepayment made or required to be made (without regard to the
proviso to the first sentence of Section 2.08(b)) under this Section 2.08.


<PAGE>
                                       32


     SECTION 2.09. INCREASED COSTS. (a) If, due to either (i) the introduction
of or any change in or in the interpretation of any law or regulation or (ii)
the compliance with any guideline or request from any central bank or other
governmental authority (whether or not having the force of law), there shall be
any increase in the cost to any Lender of agreeing to make or making, funding or
maintaining Advances (excluding for purposes of this Section 2.09 any such
increased costs resulting from changes related to taxation, as to which Section
2.12 hereof shall govern), then each Borrower shall from time to time, upon
demand by such Lender (with a copy of such demand to the Administrative Agent),
pay to the Administrative Agent for the account of such Lender additional
amounts sufficient to compensate such Lender for such increased cost. A
certificate as to the amount of such increased cost, submitted to the Parent and
the Administrative Agent by such Lender, shall be conclusive and binding for all
purposes, absent manifest error.

         (b) If any Lender determines that compliance with any law or regulation
or any guideline or request from any central bank or other governmental
authority (whether or not having the force of law) affects or would affect the
amount of capital required or expected to be maintained by such Lender or any
corporation controlling such Lender and that the amount of such capital is
increased by or based upon the existence of such Lender's commitment to lend
hereunder and other commitments of this type, then, upon demand by such Lender
(with a copy of such demand to the Administrative Agent), each Borrower shall
pay to the Administrative Agent for the account of such Lender, from time to
time as specified by such Lender, additional amounts sufficient to compensate
such Lender or such corporation in the light of such circumstances, to the
extent that such Lender reasonably determines such increase in capital to be
allocable to the existence of such Lender's commitment to lend hereunder. A
certificate as to such amounts submitted to the Parent and the Administrative
Agent by such Lender shall be conclusive and binding for all purposes, absent
manifest error.

         (c) Nothing in this Section 2.09 shall entitle any Lender to receive
any amount in respect of compensation for any such liability to increased or
additional cost, reduction, payment, forgone return or loss to the extent that
the same:

             (i) is the subject of an indemnification or additional payment
             required to be made under Section 2.12; or

             (ii) arises as a consequence of (or of any law or regulation
             implementing) (x) the proposals for international convergence of
             capital measurement and capital standards published by the Basle
             Committee on Banking Regulations and Supervisory practices in July
             1988 and/or (y) any applicable directive of the European Union (in
             each case) unless it results from any change in, or in the
             interpretation or application of, such proposals or any such
             applicable directive (or any law of regulation implementing the
             same) occurring after the date hereof; or

             (iii) arises as a result of breach by such Lender of any
             regulation, request or requirement which is in existence at the
             date of this Agreement of any


<PAGE>
                                       33


             applicable central bank or other fiscal, monetary or other
             authority (whether or not having the force of law).

     SECTION 2.10. ILLEGALITY. Notwithstanding any other provision of this
Agreement, if any Lender shall notify the Administrative Agent that the
introduction of or any change in or in the interpretation of any law or
regulation makes it unlawful, or any central bank or other governmental
authority asserts that it is unlawful, for any Lender to perform its obligations
hereunder each Borrower shall forthwith repay the outstanding principal amount
of the Advances borrowed by it and owing to such Lender and the unused
Commitments of such Lender shall terminate; PROVIDED, HOWEVER, that, before
giving any such notification, such Lender agrees to use reasonable efforts
(consistent with its internal policy and legal and regulatory restrictions) to
designate a different lending office if the making of such a designation would
allow such Lender or its lending office to continue to perform its obligations
to make Advances or to continue to fund or maintain Advances and would not, in
the reasonable judgment of such Lender, be otherwise disadvantageous to such
Lender.

     SECTION 2.11. PAYMENTS AND COMPUTATIONS. (a) Each Borrower
shall make each payment due from such Borrower hereunder not later than 11:00
A.M. (London time) on the day when due in the Permitted Currency in which the
Advance was made to the Administrative Agent at the Administrative Agent's
Account in same day funds. The Administrative Agent will promptly thereafter
cause to be distributed like funds relating to the payment of principal or
interest or facility fees ratably (other than amounts payable pursuant to
Section 2.09, 2.12 or 9.04(c)) to the Lenders, and like funds relating to the
payment of any other amount payable to any Lender to such Lender, in each case
to be applied in accordance with the terms of this Agreement. Upon its
acceptance of an Assignment and Acceptance and recording of the information
contained therein in the Register pursuant to Section 9.07(d), from and after
the effective date specified in such Assignment and Acceptance, the
Administrative Agent shall make all payments hereunder in respect of the
interest assigned thereby to the Lender assignee thereunder, and the parties to
such Assignment and Acceptance shall make all appropriate adjustments in such
payments for periods prior to such effective date directly between themselves.

         (b) Each Loan Party hereby authorizes each Lender, if and to the extent
payment owed to such Lender is not made when due hereunder held by such Lender,
to charge from time to time against any or all of such Loan Party's accounts
with such Lender any amount so due.

         (c) All computations of interest and of facility fees shall be made by
the Administrative Agent on the basis of a year of 360 days, in each case for
the actual number of days (including the first day but excluding the last day)
occurring in the period for which such interest or facility fees are payable.
Each determination by the Administrative Agent of an interest rate hereunder
shall be conclusive and binding for all purposes, absent manifest error.

         (d) Whenever any payment hereunder shall be stated to be due on a day
other than a Business Day, such payment shall be made on the next succeeding
Business Day, and such extension of time shall in such case be included in the
computation of payment of interest or facility fee, as the case may be;
PROVIDED, HOWEVER, that, if such extension would cause payment


<PAGE>
                                       34


of interest on or principal of Advances to be made in the next following
calendar month, such payment shall be made on the next preceding Business Day.

         (e) Unless the Administrative Agent shall have received notice from the
Parent prior to the date on which any payment is due to the Lenders hereunder
that any Borrower will not make such payment in full, the Administrative Agent
may assume that such Borrower has made such payment in full to the
Administrative Agent on such date and the Administrative Agent may, in reliance
upon such assumption, cause to be distributed to each Lender on such due date an
amount equal to the amount then due such Lender. If and to the extent any
Borrower shall not have so made such payment in full to the Administrative
Agent, each Lender shall repay to the Administrative Agent forthwith on demand
such amount distributed to such Lender together with interest thereon, for each
day from the date such amount is distributed to such Lender until the date such
Lender repays such amount to the Administrative Agent, at a rate specified by
the Administrative Agent to be its cost of funds.

     SECTION 2.12. TAXES. (a) Any and all payments by any Loan Party hereunder
shall be made, in accordance with Section 2.11 hereof, free and clear of and
without deduction for any and all present or future taxes, levies, imposts,
deductions, charges or withholdings, and all liabilities with respect thereto,
EXCLUDING, in the case of each Lender and the Administrative Agent, taxes
measured by or imposed upon the overall net income of the Administrative Agent,
such Lender or such Lender's applicable lending office, or any branch or
affiliate of either, any franchise taxes, branch taxes, taxes on doing business
or taxes measured by or imposed upon the overall capital or net worth of the
Administrative Agent, such Lender or such Lender's applicable lending office, or
any branch or affiliate of either, but in each case only to the extent imposed
by the jurisdiction under the laws of which the Administrative Agent, such
Lender or such Lender's applicable lending office, or any branch or affiliate of
either, is organized or is located, or in which the Administrative Agent or such
Lender is managed and controlled for tax purposes, in the case of a jurisdiction
that utilizes such criterion as the basis upon which it imposes net income
taxation, or any nation within which such jurisdiction is located or any
political sub-division thereof (all such non-excluded taxes, levies, imposts,
deductions, charges, withholdings and liabilities in respect of payments
hereunder being hereinafter referred to as "TAXES"). Subject to Section 2.12(e)
and 2.12(f), if any Loan Party shall be required by law to deduct any Taxes from
or in respect of any sum payable hereunder to any Lender or the Administrative
Agent, (i) the sum payable shall be increased as may be necessary so that after
making all required deductions (including deductions applicable to additional
sums payable under this Section 2.12) such Lender or the Administrative Agent
(as the case may be) receives an amount equal to the sum it would have received
had no such deductions been made, (ii) such Loan Party shall make such
deductions and (iii) such Loan Party shall pay the full amount deducted to the
relevant taxation authority or other authority in accordance with applicable
law.

         (b) In the event that an indemnity or additional payment is
made under this Section 2.12 for the account of the Administrative Agent or any
Lender and the Administrative Agent or such Lender, as the case may be, receives
or is granted a refund in respect of any Taxes paid pursuant to this Section
2.12, the Administrative Agent or such Lender shall remit such refund to the
applicable Borrower, net of all reasonable out-of-pocket



<PAGE>
                                       35


expenses of such Lender; PROVIDED that the applicable Borrower, upon the request
of the Administrative Agent or such Lender, agrees to return such refund to the
Administrative Agent or such Lender, as the case may be, in the event the
Administrative Agent or such Lender, as the case may be, is required to repay
such refund to the relevant taxing authority. Nothing contained herein shall
interfere with the right of the Administrative Agent or a Lender to arrange its
tax affairs in whatever manner it thinks fit nor oblige the Administrative Agent
or any Lender to apply for any refund or to disclose any information relating to
its tax affairs or any computations in respect thereof.

         (c) In addition, the Loan Parties shall pay any present or future
stamp, documentary or registration taxes or any other similar taxes, charges or
levies that arise from any payment made hereunder or from the execution,
delivery or registration of, or performing under or otherwise with respect to,
the Loan Documents (other than those imposed by reason of any transfer by any
Lender, except in the case of any transfer requested by any Loan Party)
(hereinafter referred to as "OTHER TAXES").

         (d) The Loan Parties shall indemnify each Lender and the Administrative
Agent for and hold them harmless against the full amount of Taxes or Other Taxes
(including, without limitation any Taxes imposed by any jurisdiction on amounts
payable under this Section 2.12) imposed on or paid by such Lender or the
Administrative Agent (as the case may be) and any liability (including
penalties, interest and expenses) arising therefrom or with respect thereto.
This indemnification shall be made within 30 days from the date such Lender or
the Administrative Agent (as the case may be) makes written demand therefor.

         (e) The Administrative Agent and each Lender shall, upon
becoming a party to this Agreement, confirm that it is a Qualifying Bank at such
time and agrees to notify the Parent (through the Administrative Agent) promptly
upon it becoming aware that it is not a Qualifying Bank. If the Administrative
Agent or any Lender, otherwise than by reason of any change in law or treaty or
any change in its official interpretation or administration or any change in
published revenue practice in any such case after the date on which the
Administrative Agent or such Lender, as the case may be, became a party to this
Agreement, is not or ceases to be a Qualifying Bank with respect to any Loan
Party, then such Loan Party shall not be liable to pay to the Administrative
Agent or such Lender, as the case may be, under this Section 2.12 any amount in
excess of the amount such Loan Party would have been obliged to pay to the
Administrative Agent or such Lender if the Administrative Agent or such Lender
had not ceased to be a Qualifying Bank with respect to such Loan Party.

         (f) This Section 2.12 shall not require any Borrower to pay
any indemnity or additional amounts in respect of Taxes that would not have been
imposed but for the failure of the Administrative Agent or any Lender to comply
with any certification, identification, information or other documentation
requirement that is a precondition to exemption from, or reduction in the rate
of the imposition, deduction or withholding of Taxes after the Administrative
Agent or such Lender, as the case may be, has been notified in writing by the
Parent of the necessity to comply with such requirement.

<PAGE>
                                       36



         (g) Without prejudice to the survival of any other agreement or
obligation of the Loan Parties hereunder, the agreements and obligations of the
Loan Parties contained in this Section 2.12 shall survive the payment in full of
all amounts due hereunder.

     SECTION 2.13. RULES CONCERNING ADDITIONAL AMOUNTS. Any Lender claiming any
indemnity or additional amounts payable pursuant to Section 2.12 hereof shall
use reasonable efforts (consistent with its internal policy and legal and
regulatory restrictions) to change the jurisdiction of its lending office if the
making of such a change would avoid the need for, or reduce the amount of, any
such indemnity or additional amounts that may thereafter accrue and would not,
in the reasonable judgment of such Lender, be disadvantageous to such Lender.

     SECTION 2.14. SHARING OF PAYMENTS, ETC. If any Lender shall obtain any
payment (whether voluntary, involuntary, through the exercise of any right of
set-off, or otherwise) on account of the Advances owing to it (other than
pursuant to Section 2.09, 2.12 or 9.04(c) hereof) in excess of its ratable share
of payments on account of the Advances obtained by all the Lenders, such Lender
shall forthwith purchase from the other Lenders such participations in the
Advances owing to them as shall be necessary to cause such purchasing Lender to
share the excess payment ratably with each of them; PROVIDED, HOWEVER, that if
all or any portion of such excess payment is thereafter recovered from such
purchasing Lender, such purchase from each Lender shall be rescinded and such
Lender shall repay to the purchasing Lender the purchase price to the extent of
such recovery together with an amount equal to such Lender's ratable share
(according to the proportion of (i) the amount of such Lender's required
repayment to (ii) the total amount so recovered from the purchasing Lender) of
any interest or other amount paid or payable by the purchasing Lender in respect
of the total amount so recovered. Each Loan Party agrees that any Lender so
purchasing a participation from another Lender pursuant to this Section 2.13
may, to the fullest extent permitted by law, exercise all its rights of payment
(including the right of set-off) with respect to such participation as fully as
if such Lender were the direct creditor of such Loan Party in the amount of such
participation.

     SECTION 2.15. EVIDENCE OF INDEBTEDNESS. (a) Each Lender shall
maintain in accordance with its usual practice an account or accounts evidencing
the indebtedness of each Borrower to such Lender resulting from each Advance
owing to such Lender from time to time, including the amounts of principal and
interest payable and paid to such Lender from time to time hereunder.

         (b) The Register maintained by the Administrative Agent
pursuant to Section 9.07(c) hereof shall include a control account, and a
subsidiary account for each Lender, in which accounts (taken together) shall be
recorded (i) the date and amount of each Borrowing made hereunder and each
Interest Period applicable thereto, (ii) the terms of each Assignment and
Acceptance delivered to and accepted by it, (iii) the amount of any principal or
interest due and payable or to become due and payable from each Borrower to each
Lender hereunder, and (iv) the amount of any sum received by the Administrative
Agent from each Borrower hereunder and each Lender's share thereof.


<PAGE>
                                       37


         (c) Entries made in good faith by the Administrative Agent in the
Register pursuant to subsection (b) above, and by each Lender in its account or
accounts pursuant to subsection (a) above, shall be PRIMA FACIE evidence of the
amount of principal and interest due and payable or to become due and payable
from each Borrower to, in the case of the Register, each Lender and, in the case
of such account or accounts, such Lender, under this Agreement, absent manifest
error; PROVIDED, HOWEVER, that the failure of the Administrative Agent or such
Lender to make an entry, or any finding that an entry is incorrect, in the
Register or such account or accounts shall not limit or otherwise affect the
obligations of such Borrower under this Agreement.

     SECTION 2.16. USE OF PROCEEDS. The proceeds of the Advances shall be
available (and the Borrowers agree that they shall use such proceeds) solely (i)
to repay and/or to make payments to the Parent in order to enable the Parent to
repay the Nortel Facility, (ii) to finance the cost (including the cost of
design, development, acquisition, construction, installation, improvement,
transportation or integration) of acquiring the Telecommunications Equipment,
(iii) to pay transaction costs incurred in connection with the Bridge Facility
and (iv) for working capital and other general corporate purposes of the Parent,
the Borrowers and their respective Subsidiaries.

     SECTION 2.17. REMOVAL OF LENDER. In the event that any Lender
demands payment of costs, indemnification or additional amounts pursuant to
Section 2.09 or Section 2.12 hereof then (subject to such Lender's right to
rescind such demand within 10 days after the notice from the Parent referred to
below) the Parent may, upon 20 days' prior written notice to such Lender and the
Administrative Agent, elect to cause such Lender to assign its Advances and
Commitments in full to an assignee institution selected by the Parent that meets
the criteria of an Eligible Assignee and is reasonably satisfactory to the
Administrative Agent, so long as such Lender receives payment in full in cash of
the outstanding principal amount of all Advances made by it and all accrued and
unpaid interest thereon and all other amounts then due and payable to such
Lender as of the date of such assignment (including, without limitation, amounts
owing pursuant to Section 2.09 or Section 2.12 hereof), and in such case such
Lender agrees to make such assignment and assume all obligations of such Lender
hereunder, in accordance with Section 9.07 hereof.

     SECTION 2.18. CERTAIN RULES RELATING TO THE PAYMENT OF ADDITIONAL AMOUNTS.
If a Lender voluntarily changes its lending office and the effect of such
change, as of the date of such change, would be to cause a Borrower to become
obligated to pay an indemnity or additional amount under Section 2.09 or Section
2.12 hereof that such Borrower was not theretofore obligated to pay, then such
Borrower shall not be obligated to pay such indemnity or additional amount.


<PAGE>
                                       38


                                   ARTICLE III

                              CONDITIONS TO LENDING

     SECTION 3.01. CONDITIONS PRECEDENT. The obligations of the Lenders to make
Advances on the occasion of the initial Borrowing shall be subject to the
following conditions precedent:

         (a) There shall have occurred no Material Adverse Change since
    December 31, 1998.

         (b) There shall exist no action, suit, investigation, litigation or
    proceeding pending or threatened in any court or before any arbitrator or
    governmental or regulatory agency or authority that (i) would reasonably be
    expected to have a Material Adverse Effect or (ii) seeks to prohibit or
    restrain the transactions contemplated hereby.

         (c) The Lenders shall be reasonably satisfied with the corporate and
    legal structure and the terms and conditions of the capitalization of the
    Parent, including, without limitation, the charter and by-laws of the Parent
    and each material agreement or instrument relating thereto, to the extent
    that, taken as a whole, the same differ materially from as in effect on
    February 19, 1999 and from as disclosed in the Parent's filings with the
    Commission or its public announcements.

         (d) All governmental and third party consents and approvals if any
    (other than any such consents and approvals the absence of which,
    individually and in the aggregate would not reasonably be expected to have a
    Material Adverse Effect), necessary in connection with the transactions
    contemplated hereby shall have been obtained (without the imposition of any
    conditions that would reasonably be expected to have a Material Adverse
    Effect) and shall remain in effect; all applicable waiting periods shall
    have expired without any adverse action being taken by any competent
    authority (other than any such actions that, individually or in the
    aggregate, would not reasonably be expected to have a Material Adverse
    Effect); and no law or regulation shall be applicable that restrains,
    prevents or imposes materially adverse conditions upon the transactions
    contemplated hereby.

         (e) All written information (other than the Projections) furnished to
    the Administrative Agent by the Parent or its advisors on behalf of the
    Parent prior to the Closing Date (the "INFORMATION"), taken as a whole,
    shall not have contained any untrue statement of a material fact or omitted
    to state a material fact necessary in order to make the statements contained
    therein not misleading in light of the circumstances under which such
    statements were made and no additional information shall have come to the
    attention of the Administrative Agent or the Lenders that (i) was not known
    to the Initial Lenders or publicly available to them through the Parent's
    public announcements or filings with the Commission on such date and (ii)
    would reasonably be expected to have a Material Adverse Effect.


<PAGE>
                                       39


         (f) All loans made by the Lenders to the Borrowers or any of their
    affiliates shall be in full compliance with the Federal Reserve's Margin
    Regulations.

         (g) The Parent shall have paid all accrued fees of the Administrative
    Agent and the Lenders due and payable.

         (h) Except in each case as would not reasonably be expected to have a
    Material Adverse Effect, the Lead Arrangers shall be reasonably satisfied
    that (i) the Parent and its subsidiaries will be able to meet its
    obligations under all employee and retiree welfare plans, (ii) the employee
    benefit plans of the Parent and its ERISA affiliates are funded in
    accordance with at least the minimum statutory requirements, (iii) no
    "reportable event" (as defined in ERISA, but excluding events for which
    reporting has been waived) has occurred as to any such employee benefit plan
    and (iv) no termination of, or withdrawal from, any such employee benefit
    plan has occurred or is contemplated.

             (i) The Administrative Agent shall have received on or before the
         Closing Date the following, each dated such day, in form and substance
         reasonably satisfactory to the Administrative Agent and in sufficient
         copies for each Lender:

             (i) Certified copies of the resolutions of each Loan Party
         approving the Loan Documents to which it is a party and, in the case of
         the Parent, making the determinations required by clause (vi) of the
         second paragraph of Section 4.05 of the Indentures, and of all
         documents evidencing other necessary corporate action and governmental
         approvals, if any, with respect to the Loan Documents.

             (ii) Either an officer's certificate of each Loan Party or
         certified excerpts from the Commercial Register (HANDELSREGISTER),
         STATUTS or similar governmental documents of each Loan Party with
         respect to the directors and officers of such Loan Party evidencing
         their authority to sign the Loan Documents to which such Loan Party is
         a party and the other documents to be delivered hereunder.

             (iii) A favorable opinion of Debevoise & Plimpton, New York counsel
         for the Loan Parties, in form and substance reasonably satisfactory to
         the Administrative Agent.

             (iv) Favorable opinions of French, Luxembourg, German, Swiss and
         U.K. counsel for the Loan Parties, each substantially in the form of
         Exhibit D hereto and as to such other matters as any Lender through the
         Administrative Agent may reasonably request.


<PAGE>
                                       40


             (v) A favorable opinion of Shearman & Sterling, New
         York counsel for the Administrative Agent, in form and substance
         reasonably satisfactory to the Administrative Agent.

             (vi) A solvency certificate from the chief financial officer of the
         Parent on behalf of each Obligor in form and substance reasonably
         satisfactory to the Lenders.

     SECTION 3.02. CONDITIONS PRECEDENT TO CERTAIN BORROWINGS. The obligation
of each Lender to make an Advance on the occasion of each Borrowing that would
result in the aggregate outstanding amount of the Advances exceeding $25 million
(or the Euro Equivalent thereof) shall be subject to the additional conditions
precedent:

         (a) the Security Agent shall have received as soon as practicable but
    in no event later than 30 days after the Closing Date, the following in form
    and substance reasonably satisfactory to the Security Agent and in
    sufficient copies for each Lender;

             (i) A Pledge Agreement dated on or within 30 days after the Closing
         Date (the "FRENCH PLEDGE AGREEMENT"), duly executed and delivered by
         Carrier 1 UK Limited and Carrier 1 France Holding, together with:

                 (A) a favorable opinion of Debevoise & Plimpton, French counsel
             for the Loan Parties, with respect to the effectiveness of the
             security granted under the French Pledge Agreement in form and
             substance reasonably satisfactory to the Security Agent;

                 (B) evidence of the completion of all recordings and filings of
             or with respect to the French Pledge Agreement that the Security
             Agent may deem reasonably necessary or desirable in order to
             perfect and protect the Liens created thereby; and

                 (C) evidence that all other action that the Lenders may deem
             reasonably necessary in order to perfect and protect the Liens
             created under the French Pledge Agreement has been taken.

             (ii) A Pledge of Shares dated on or within 30 days after the
         Closing Date (the "SWISS PLEDGE AGREEMENT"), duly executed and
         delivered by the Parent and Carrier 1 UK Limited, together with:

                 (A) a favorable opinion of Bill, Isenegger & Ackerman, Swiss
             counsel for the Loan Parties, with respect to the effectiveness of
             the security granted under the Swiss Pledge Agreement in form and
             substance reasonably satisfactory to the Security Agent;

                 (B) evidence of the completion of all recordings and filings of
             or with respect to the Swiss Pledge Agreement that the Security

<PAGE>
                                       41


             Agent may deem reasonably necessary or desirable in order to
             perfect and protect the Liens created thereby; and

                 (C) evidence that all other action that the Lenders may deem
             reasonably necessary in order to perfect and protect the Liens
             created under the Swiss Pledge Agreement has been taken.

             (iii) a Deed of Charge over shares dated on or within 30 days after
         the Closing Date (the "DEED OF CHARGE") duly executed and delivered by
         the Parent together with:

                 (A) certificates representing the entire issued share
             capital of Carrier 1 UK Ltd together with undated stock transfer
             forms executed in blank;

                 (B) a favorable opinion of Ashurst Morris Crisp, U.K. counsel
             to the Loan Parties, with respect to the effectiveness of the
             security granted pursuant to the Deed of Charge in form and
             substance reasonably satisfactory to the Security Agent;

                 (C) a certified copy of the Register of Shareholders for
             Carrier 1 UK Ltd evidencing that (i) the Parent is the sole
             shareholder of record of Carrier 1 UK Ltd and (ii) all redeemable
             preference shares issued by Carrier 1 UK Ltd have been redeemed in
             full, or a certified copy of stock transfer forms evidencing the
             transfer of all outstanding shares of Carrier 1 UK Limited to the
             Parent;

                 (D) evidence of the completion of all recordings and filings of
             or with respect to the Deed of Charge that the Security Agent may
             deem reasonably necessary or desirable in order to perfect and
             protect the Liens created thereby; and

                 (E) evidence that all other action that the Lenders may deem
             reasonably necessary in order to perfect and protect the Liens
             created under the Deed of Charge has been duly taken.

             (iv) A Pledge Agreement dated on or within 30 days after the
         Closing Date (the "GERMAN PLEDGE AGREEMENT") duly executed and
         delivered by the Parent and Carrier 1 Holding GmbH together with:

                 (A) a favorable opinion of Hengeler Mueller Weitzel Wirtz,
             German counsel to the Loan Parties with respect to the
             effectiveness of the security granted pursuant to the German Pledge
             Agreement, in form and substance reasonably satisfactory to the
             Security Agent;


<PAGE>
                                       42


                 (B) evidence of the completion of all recordings and filings of
             or with respect to the German Pledge Agreement that the Security
             Agent may deem reasonably necessary or desirable in order to
             perfect and protection the Liens created thereby; and

                 (C) evidence that all other action that the Lenders may deem
             reasonably necessary in order to perfect and protect the Liens
             created under the German Pledge Agreement have been taken.

     SECTION 3.03. CONDITIONS PRECEDENT TO EACH BORROWING. The obligation of
each Lender to make an Advance on the occasion of each Borrowing (including the
initial Borrowing) shall be subject to the additional conditions precedent:

         (a) on the date of such Borrowing, the following statements shall be
    true (and each of the giving of the applicable Notice of Borrowing and the
    acceptance by each Borrower of the proceeds of such Borrowing shall
    constitute a representation and warranty by such Borrower that on the date
    of such Borrowing such statements are true):

                           (i) the representations and warranties contained in
                  Section 4.01 hereof are correct on and as of the date of such
                  Borrowing, before and after giving effect to such Borrowing
                  and to the application of the proceeds therefrom, as though
                  made on and as of such date, and

                           (ii) no event has occurred and is continuing, or
                  would result from such Borrowing or from the application of
                  the proceeds therefrom, that constitutes a Default or Event of
                  Default;

         (b) each Acceding Borrower (if any) shall have signed an accession
    agreement in the form of Exhibit E hereto and become an Acceding Guarantor
    and, if so requested by the Administrative Agent, the shares of such
    Acceding Borrower shall have been pledged pursuant to a Pledge Agreement;
    and

         (c) the Administrative Agent shall have received such other approvals,
    opinions or documents as any Lender through the Administrative Agent may
    reasonably request.

     SECTION 3.04. DETERMINATIONS UNDER SECTION 3.01. For purposes of
determining compliance with the conditions specified in Section 3.01, each
Lender shall be deemed to have consented to, approved or accepted or to be
satisfied with each document or other matter required thereunder to be consented
to or approved by or acceptable or satisfactory to the Lenders unless an officer
of the Administrative Agent responsible for the transactions contemplated by
this Agreement shall have received notice from such Lender prior to the Closing
Date specifying its objection thereto.


<PAGE>
                                       43


                                   ARTICLE IV

                         REPRESENTATIONS AND WARRANTIES

     SECTION 4.01. REPRESENTATIONS AND WARRANTIES. The Parent represents and
warrants as follows:

         (a) The Parent and each of its Subsidiaries (i) is duly incorporated or
    organized and validly existing under the laws of the jurisdiction of its
    formation, (ii) is duly qualified in each other jurisdiction in which it
    owns or leases property or in which the conduct of its business requires it
    to so qualify except where the failure to so qualify would not be reasonably
    be expected to have a Material Adverse Effect and (iii) has all requisite
    corporate or other power and authority (including, without limitation, all
    governmental licenses, permits and other approvals other than those the
    failure to have which would not reasonably be expected to have a Material
    Adverse Effect) to own or lease and operate its properties and to carry on
    its business as now conducted and as proposed to be conducted. All of the
    outstanding shares or other ownership interests in each Loan Party (other
    than the Parent) have been validly issued, are fully paid and non-assessable
    and (except for directors' and other qualifying shares) are owned by the
    Parent or one or more of the Parent's subsidiaries free and clear of all
    Liens. Attached as Schedule 4.01(a) is a complete and accurate corporate
    structure chart of the Parent and its Subsidiaries, showing as of the date
    hereof the percentage ownership of each class of shares or other ownership
    interests of or in such companies.

         (b) The execution, delivery and performance by each Loan Party of each
    Loan Document to which it is a party and the consummation of the other
    transactions contemplated by the Loan Documents are within such Loan Party's
    corporate or other powers, have been duly authorized by all necessary
    corporate or other action, and do not (i) contravene such Loan Party's
    formation documents, (ii) violate any law, rule, regulation, order, writ,
    judgment, injunction, decree, determination or award, (iii) conflict with or
    result in the breach of, or constitute a default under, any contract, loan
    agreement, indenture, mortgage, deed of trust, lease or other instrument
    binding on or affecting any Loan Party, any Loan Party's Subsidiaries or any
    of their properties or (iv) except for the Liens under the Pledge Agreements
    and the Permitted Liens, result in or require the creation or imposition of
    any Lien upon or with respect to any of the properties of any Loan Party or
    any of its Subsidiaries, other than, in the case of clauses (ii), (iii) and
    (iv) above, any such contravention, conflict, breach, default or Lien that
    does not arise under any agreement or instrument evidencing Indebtedness and
    that, individually or in the aggregate, would not reasonably be expected to
    have a Material Adverse Effect. No Loan Party or any of its Subsidiaries is
    in violation of any law, rule, regulation, order, writ, judgment,
    injunction, decree, determination or award or in breach of any such
    contract, loan agreement, indenture, mortgage, deed of trust, lease or other
    instrument, the violation or breach of which would reasonably be expected to
    have a Material Adverse Effect.


<PAGE>
                                       44


         (c) No authorization or approval or other action by, and no notice to
    or filings with, any governmental authority or regulatory body or any other
    third party is required (other than any such authorizations, approvals,
    notices or filings, the absence of which, individually or in the aggregate,
    would not reasonably be expected to have a Material Adverse Effect) for (i)
    the due execution, delivery, recordation, filing or performance by any Loan
    Party of any Loan Document to which it is a party or the consummation of the
    transactions contemplated by the Loan Documents, (ii) the grant by any Loan
    Party of the Liens granted by it pursuant to the Pledge Agreements.

         (d) Each of the Loan Documents has been duly executed and delivered by
    each Loan Party thereto. Each of the Loan Documents is the legal, valid and
    binding obligation of each Loan Party thereto enforceable against such Loan
    Party in accordance with their respective terms, except as enforceability
    may be limited by applicable bankruptcy, insolvency, reorganization,
    moratorium or similar laws affecting creditors' rights generally and by
    general equitable principles (regardless of whether enforcement is sought by
    proceedings in equity or at law) and except as indicated in any customary
    exceptions contained in the legal opinions delivered pursuant to Sections
    3.01 and 3.02 hereof.

         (e) The Consolidated balance sheet of the Parent and its Subsidiaries
    as at December 31, 1998, and the related Consolidated statements of income
    and cash flows of the Parent and its Subsidiaries for the fiscal year then
    ended, accompanied by an opinion of Deloitte & Touche Experta AG,
    independent public accountants, and the Consolidated balance sheet of the
    Parent and its Subsidiaries as at September 30, 1999, and the related
    Consolidated statements of income and cash flows of the Parent and its
    Subsidiaries for the nine months then ended, duly certified by the chief
    financial officer of the Parent, copies of which have been furnished to each
    Lender, fairly present, subject, in the case of said balance sheet as at
    September 30, 1999, and said statements of income and cash flows for the
    nine months then ended, to year-end audit adjustments and the absence of
    footnotes, the Consolidated financial condition of the Parent and its
    Subsidiaries as at such dates and the Consolidated results of the operations
    of the Parent and its Subsidiaries for the periods ended on such dates, all
    in accordance with GAAP.

         (f) Since December 31, 1998, there has been no Material Adverse Change.

         (g) There is no action, suit, investigation, litigation or proceeding
    pending or (to the Parent's knowledge) threatened in any court or before any
    arbitrator or governing or regulatory agency affecting any Loan Party or any
    of its Subsidiaries that (i) would reasonably be expected to have a Material
    Adverse Effect or (ii) seeks to prohibit or restrain the consummation of the
    transactions contemplated hereby.

         (h) No Loan Party nor any of its Subsidiaries is engaged in the
    business of extending credit for the purpose of purchasing or carrying
    margin stock (within the meaning of Regulation U issued by the Board of
    Governors of the Federal Reserve System), and no proceeds of any Advance
    will be used to purchase or carry any margin

<PAGE>
                                       45


    stock or to extend credit to others for the purpose of purchasing or
    carrying any margin stock.

         (i) Each Loan Party and such Loan Party's Subsidiaries have filed, have
    caused to be filed or have been included in all material tax returns
    required to be filed and has paid all material taxes shown thereon to be
    due, together with applicable interest and penalties except for any such tax
    that is being contested in good faith and by proper proceedings and as to
    which appropriate reserves are being maintained.

         (j) Each Loan Party is, individually and together with its
    Subsidiaries, taken as a whole, immediately before and immediately after
    giving effect to the initial Borrowings hereunder, Solvent.

         (k) Neither the business nor the properties of any Loan Party or any of
    its Subsidiaries are affected by any fire, explosion, accident, strike,
    lockout or other labor dispute, drought, storm, hail, earthquake, embargo,
    act of God or of the public enemy or other casualty (whether or not covered
    by insurance) that would reasonably be expected to have a Material Adverse
    Effect (after taking into consideration any applicable insurance coverage).

         (l) Each Loan Party and each of its Subsidiaries complies, in all
    respects, with all requirements of applicable Environmental Laws where
    failure to do so has, or would reasonably be expected to have, a Material
    Adverse Effect.

         (m) No Loan Party nor any of its Subsidiaries is an "investment
    company" (as such term is defined or used in the Investment Company Act of
    1940, as amended).

         (n) No Loan Party nor any Subsidiary thereof is a "holding company", a
    "public utility company" or an "affiliate" or "subsidiary company" of a
    "registered holding company" within the meaning of the Public Utility
    Holding Company Act of 1935, as amended.

         (o) The Information, taken as a whole, does not contain any untrue
    statement of a material fact or omit to state a material fact necessary in
    order to make the statements contained therein not misleading as of the
    Closing Date in light of the circumstances under which such statements were
    made.

         (p) Each Pledge Agreement creates or will create a valid and perfected
    or otherwise effective first priority security interest in the Pledged
    Shares, securing the payment of the obligations of the Loan Parties to the
    extent provided therein and in this Agreement, and all filings and other
    actions necessary to perfect and protect such security interest have been or
    will be duly taken in accordance with this Agreement. The Loan Parties are
    the legal and beneficial owners of the Pledged Shares free and clear of any
    Lien, except for the liens and security interests created or permitted under
    the Loan Documents.


<PAGE>
                                       46


         (r) All written financial, business and other projections, forecasts,
    estimates, pro formas and other forward-looking information (the
    "PROJECTIONS"), if any, that have been prepared by the Parent or on the
    Parent's behalf or by any of its representatives and made available to the
    Lenders on or prior to the Closing Date in connection with this Agreement
    were prepared in good faith on the basis of the assumptions stated therein,
    which assumptions were believed by the Parent to be reasonable in the light
    of conditions existing at the time of delivery of such Projections (it being
    understood that such Projections are subject to significant uncertainties
    and contingencies, many of which are beyond the Parent's control), and
    represented, at the time of delivery, the Parent's best estimate of its
    future financial performance.

                                     ARTICLE V

                                    COVENANTS

     SECTION 5.01. AFFIRMATIVE COVENANTS. So long as any Advance shall remain
unpaid or any Lender shall have any Commitment hereunder, the Parent will:

         (a) COMPLIANCE WITH LAWS, ETC. Comply, and cause each of its Restricted
    Subsidiaries to comply in all material respects, with all applicable laws,
    rules, regulations and orders, such compliance to include, without
    limitation, compliance with ERISA and Environmental Laws, except where the
    failure to so comply would not reasonably be expected to have a Material
    Adverse Effect.

         (b) PAYMENT OF TAXES, ETC. Pay or discharge, and cause each of its
    Restricted Subsidiaries to pay or discharge, before the same shall become
    delinquent, (i) all material taxes, assessments and governmental charges,
    levied or imposed upon (A) the Parent or any such Restricted Subsidiary; (B)
    the income or profits of any such Restricted Subsidiary which is a
    corporation or other corporate entity; or (C) the property of the Parent or
    any such Restricted Subsidiary; and (ii) all material lawful claims for
    labor, materials, and supplies that, if unpaid, might by law become a lien
    or an encumbrance upon the property of the Parent or any such Restricted
    Subsidiary; PROVIDED, HOWEVER, that the Parent shall not be required to pay
    or discharge, or cause to be paid or discharged, any such tax, assessment,
    charge or claim (x) the amount, applicability or validity of which is being
    contested in good faith by appropriate proceedings and for which adequate
    reserves have been established to the extent required by GAAP or (y) if
    failure to do so would not (as determined by the Parent in good faith)
    reasonably be expected to have a Material Adverse Effect or (z) if any
    resulting Lien constitutes a Permitted Lien or otherwise complies with
    Section 5.02(g) hereof.

         (c) MAINTENANCE OF INSURANCE. Provide or cause to be provided, for
    itself and its Restricted Subsidiaries, insurance (including appropriate
    self-insurance) against loss or damage of the kinds customarily insured
    against by corporations similarly situated and owning like properties,
    including, but not limited to, products liability insurance and public
    liability insurance, with reputable insurers, in such amounts, with
<PAGE>

                                       47


         such deductibles and by such methods as shall be customary for
         corporations similarly situated in the industry in which the Parent or
         any such Restricted Subsidiary, as the case may be, is then conducting
         business; PROVIDED that in the judgment of the Parent such insurance is
         available to the Parent on commercially reasonable terms and is
         desirable.

                  (d) PRESERVATION OF CORPORATE EXISTENCE, ETC. Preserve and
         keep in full force and effect, and cause each of its Restricted
         Subsidiaries to preserve and keep in full force and effect, its
         corporate existence, rights (charter and statutory) licenses and
         franchises; PROVIDED, HOWEVER, that the Parent and its Subsidiaries may
         consummate any merger or consolidation permitted under Section 5.02(j)
         and PROVIDED, FURTHER, that the Parent shall not be required to
         preserve any right, license or franchise, or the existence of any
         Restricted Subsidiary, if the maintenance or preservation thereof is,
         in the judgment of the Parent, no longer desirable in the conduct of
         the business of the Parent and its Restricted Subsidiaries, taken as a
         whole.

                  (e) MAINTENANCE OF PROPERTIES, ETC. Cause all properties used
         or useful in the conduct of its business or the business of any of its
         Restricted Subsidiaries to be maintained and kept in good condition,
         repair and working order and supplied with all necessary equipment and
         cause to be made all necessary repairs, renewals, replacements,
         betterments and improvements thereof, all as in the judgment of the
         Parent may be necessary so that the business carried on in connection
         therewith may be properly and advantageously conducted at all times;
         PROVIDED that nothing in this Section 5.01(e) shall prevent the Parent
         or any Restricted Subsidiary from omitting to take such action or
         discontinuing the use, operation or maintenance of any of such
         properties or disposing of any of them, if such omission,
         discontinuance or disposal is, in the judgment of the Parent, desirable
         in the conduct of the business of the Parent or such Restricted
         Subsidiary.

                  (f) WHOLLY OWNED SUBSIDIARIES. Ensure that each Obligor shall
         remain a Wholly Owned Subsidiary of the Parent.

                  (g) REPORTING REQUIREMENTS.  Furnish to the Lenders:

                           (i) as soon as available and in any event within 45
                  days after the end of each of the first three quarters of each
                  fiscal year of the Parent, Consolidated balance sheets of the
                  Parent and its Subsidiaries as of the end of such quarter and
                  Consolidated statements of income and cash flows of the Parent
                  and its Subsidiaries for the period commencing at the end of
                  the previous fiscal year and ending with the end of such
                  quarter, duly certified (subject to year-end audit adjustments
                  and the absence of footnotes) by the chief financial officer
                  of the Parent as having been prepared in accordance with GAAP
                  and certificates of the chief financial officer of the Parent
                  as to compliance with the terms of this Agreement and setting
                  forth in reasonable detail the calculations necessary to
                  demonstrate compliance with Section 5.03 hereof, PROVIDED that
                  in the event of any change in GAAP used in the


<PAGE>
                                       48


                  preparation of such financial statements, the Parent shall
                  also provide, if necessary for the determination of compliance
                  with Section 5.03 hereof, a statement of reconciliation
                  conforming such financial statements to GAAP as formerly in
                  effect;

                           (ii) as soon as available and in any event within 90
                  days after the end of each fiscal year of the Parent, a copy
                  of the annual report for such year for the Parent and its
                  Subsidiaries, containing audited Consolidated balance sheets
                  of the Parent and its Subsidiaries as of the end of such
                  fiscal year and audited Consolidated statements of income and
                  cash flows of the Parent and its Subsidiaries for such fiscal
                  year, in each case accompanied by a report of Deloitte &
                  Touche Experta AG or other independent public accountants
                  reasonably acceptable to the Initial Lenders, which report
                  shall be without a "going concern" or like qualification or
                  exception, or qualification arising out of the scope of the
                  audit, PROVIDED that in the event of any change in GAAP used
                  in the preparation of such financial statements, the Parent
                  shall also provide, if necessary for the determination of
                  compliance with Section 5.03 hereof, a statement of
                  reconciliation conforming such financial statements to GAAP as
                  formerly in effect;

                           (iii) as soon as available and in any event no later
                  than 30 days after the end of each fiscal year of the Parent,
                  forecasts prepared by management of the Parent, in form
                  reasonably satisfactory to the Administrative Agent, of
                  balance sheets, income statements and cash flow statements on
                  a monthly basis for the fiscal year following such fiscal year
                  then ended;

                           (iv) promptly after the end of each fiscal quarter, a
                  report from the Parent, in form reasonably satisfactory to the
                  Administrative Agent, comparing the aggregate amount of actual
                  sales of ducts, dark fiber, lit fiber and capacity and fiber
                  swaps to the business plan of the Parent most recently
                  presented to the Lenders from time to time.

                           (v) promptly after gaining knowledge of the
                  occurrence of each Default continuing on the date of such
                  statement, a statement of the chief financial officer of the
                  Parent setting forth details of such Default and the action
                  that the Parent has taken and proposes to take with respect
                  thereto;

                           (vi) promptly after the sending or filing thereof,
                  copies of all reports that any Loan Party sends to any of its
                  security holders, and copies of all reports and registration
                  statements that any Loan Party files with the Commission or
                  any national securities exchange;

                           (vii) promptly after the commencement thereof, notice
                  of all actions and proceedings before any court, governmental
                  agency or arbitrator affecting the Parent or any of its
                  Subsidiaries that would reasonably be expected to have


<PAGE>
                                       49


                  a Material Adverse Effect or seek to prohibit or restrain the
                  consummation of the transactions contemplated hereby; and

                           (viii) such other information respecting the Parent
                  or any of its Subsidiaries as any Lender through the
                  Administrative Agent may from time to time reasonably request.

                  (h) DELIVERY OF SECURITY. Promptly, but in no event later than
         30 days after the Closing Date, satisfy and cause each applicable
         Subsidiary to satisfy, the conditions precedent provided in Section
         3.02 hereof to the extent not satisfied on the Closing Date.

                  (i) GUARANTORS. Ensure that at the end of each quarter the
         combined book value of the assets (other than cash, cash equivalents
         and restricted investments) of the Guarantors represent at least 80% of
         the Consolidated book value of the assets (other than cash, cash
         equivalents and restricted investments) of the Parent and its
         Subsidiaries taken as a whole.

                  SECTION 5.02. NEGATIVE COVENANTS. So long as any Advance shall
remain unpaid or any Lender shall have any Commitment hereunder, the Parent
shall not, and shall cause its Restricted Subsidiaries not to:

                  (a) INDEBTEDNESS. (i) Incur any Indebtedness (other than the
         Advances); PROVIDED, HOWEVER, that the Parent may incur Indebtedness
         if, after giving effect to the Incurrence of such Indebtedness and the
         receipt and application of the proceeds therefrom, the Consolidated
         Leverage Ratio would be greater than zero and less than 6:1; PROVIDED,
         FURTHER, that the Parent and any Restricted Subsidiary (except as
         specified below) may Incur each and all of the following:

                           (A) Indebtedness under the High Yield Notes as in
                  effect on the date hereof and as amended from time to time in
                  accordance with the terms hereof;

                           (B) Indebtedness owed (x) to the Parent constituting
                  Permitted Intercompany Indebtedness or (y) to any Restricted
                  Subsidiary; PROVIDED that any event which results in any such
                  Restricted Subsidiary ceasing to be a Restricted Subsidiary or
                  any subsequent transfer of such Indebtedness (other than to
                  the Parent or another Restricted Subsidiary) shall be deemed,
                  in each case, to constitute an Incurrence of such Indebtedness
                  not permitted by this clause (B);

                           (C) Indebtedness issued in to refinance, then
                  outstanding Indebtedness (other than Indebtedness Incurred
                  under clause (B), (D), (E), (G), (J) or (K) of this Section
                  5.02(a)(i)) and any refinancings thereof in an amount not to
                  exceed the amount so refinanced (plus premiums, accrued
                  interest, fees and expenses); PROVIDED that Indebtedness the
                  proceeds of which are used to refinance the Advances in part
                  or Indebtedness that is pari passu with, or


<PAGE>
                                       50


                  expressly subordinated in right of payment to, the Advances
                  shall only be permitted under this clause (C) if (x) in case
                  the Advances are refinanced in part or the Indebtedness to be
                  refinanced is pari passu with the Advances, such new
                  Indebtedness, by its terms or by the terms of any agreement or
                  instrument pursuant to which such new Indebtedness is
                  outstanding, is expressly made pari passu with, or subordinate
                  in right of payment to, the remaining Advances, (y) in case
                  the Indebtedness to be refinanced is subordinated in right of
                  payment to the Advances, such new Indebtedness, by its terms
                  or by the terms of any agreement or instrument pursuant to
                  which such new Indebtedness is issued or remains outstanding,
                  is expressly made subordinate in right of payment to the
                  Advances at least to the extent that the Indebtedness to be
                  refinanced is subordinated to the Advances and (z) such new
                  Indebtedness, determined as of the date of Incurrence of such
                  new Indebtedness, does not mature prior to the Stated Maturity
                  of the Indebtedness to be refinanced and the Average Life of
                  such new Indebtedness is at least equal to the remaining
                  Average Life of the Indebtedness to be refinanced; and
                  PROVIDED FURTHER that in no event may Indebtedness of the
                  Parent be refinanced by means of any Indebtedness of any
                  Restricted Subsidiary pursuant to this clause (C);

                           (D) Indebtedness (x) in respect of performance,
                  surety, appeal or similar bonds provided in the ordinary
                  course of business, and (y) arising from agreements providing
                  for indemnification, adjustment of purchase price or similar
                  obligations, or from Guarantees or letters of credit, bankers'
                  acceptances, surety or performance bonds or other similar
                  instruments securing any obligations of the Parent or any of
                  its Restricted Subsidiaries pursuant to such agreements, in
                  any case Incurred in connection with the disposition of any
                  business, assets or Restricted Subsidiary (other than
                  Guarantees of Indebtedness Incurred by any Person acquiring
                  all or any portion of such business, assets or Restricted
                  Subsidiary for the purpose of financing such acquisition), in
                  a principal amount not to exceed the gross proceeds actually
                  received by the Parent or any Restricted Subsidiary in
                  connection with such disposition;

                           (E) Guarantees of the Advances by any Restricted
                  Subsidiary;

                           (F) Indebtedness (including Guarantees) incurred to
                  finance or refinance the cost (including the cost of design,
                  development, acquisition, construction, installation,
                  improvement, transportation or integration) to acquire
                  equipment, inventory or network asset (including leases on an
                  indefeasible right-to-use basis and multiple investment units)
                  (including acquisitions by way of Capitalized Lease and
                  acquisitions of the Capital Stock of a Person that becomes a
                  Restricted Subsidiary to the extent of the fair market value
                  of the equipment, inventory or network assets so acquired) by
                  the Parent or a Restricted Subsidiary and any other Network
                  Financing Borrowings not financed pursuant to an Advance
                  hereunder, in an aggregate amount outstanding at any time not
                  to exceed $75 million;

<PAGE>
                                       51


                           (G) Indebtedness of the Parent not to exceed, at any
                  one time outstanding (after giving effect to any refinancing
                  thereof), two times the sum of (A) the Net Cash Proceeds
                  received by the Parent after the Closing Date as a capital
                  contribution or from the issuance and sale of its Capital
                  Stock (other than Disqualified Stock) to a Person that is not
                  a Subsidiary of the Parent, to the extent (I) such capital
                  contribution or Net Cash Proceeds have not been used pursuant
                  to clause (III)(2) of clause (i) or clause (C), (D), (E) or
                  (F) of clause (ii) of Section 5.02(b) to make a Restricted
                  Payment and (II) if such capital contribution or Net Cash
                  Proceeds are used to consummate a transaction pursuant to
                  which the Parent Incurs Acquired Indebtedness, the amount of
                  such Net Cash Proceeds exceeds one-half of the amount of
                  Acquired Indebtedness so Incurred and (B) 80% of the fair
                  market value of property (other than cash and cash
                  equivalents) received by the Parent after the Closing Date as
                  a capital contribution or from the sale of its Capital Stock
                  (other than Disqualified Stock) to a Person that is not a
                  Subsidiary of the Parent, to the extent (I) such capital
                  contribution or sale of Capital Stock has not been used
                  pursuant to clause (C), (D) or (G) of Section 5.02(b)(ii) to
                  make a Restricted Payment and (II) if such capital
                  contribution or Capital Stock is used to consummate a
                  transaction pursuant to which the Parent Incurs Acquired
                  Indebtedness, 80% of the fair market value of the property
                  received exceeds one-half of the amount of Acquired
                  Indebtedness so Incurred PROVIDED that such Indebtedness does
                  not mature prior to the Stated Maturity of the Advances and
                  has an Average Life longer than the Advances;

                           (H) Acquired Indebtedness;

                           (I) Strategic Subordinated Indebtedness;

                           (J) Indebtedness in respect of the German Network L/C
                  in excess of $85 million, bankers' acceptances and letters of
                  credit, all (other than incremental Indebtedness under the
                  German Network L/C) in the ordinary course of business, in an
                  aggregate amount outstanding at any time not to exceed $10
                  million;

                           (K) the German Network L/C; and

                           (L) subordinated Indebtedness of the Parent (in
                  addition to Indebtedness permitted under clauses (A) through
                  (K) above) in an aggregate principal amount outstanding at any
                  time (after giving effect to any refinancing thereof) not to
                  exceed $100 million and maturing no earlier than the Maturity
                  Date.

                  (ii) For purposes of determining compliance with any
         Dollar-denominated restriction on the Incurrence of Indebtedness
         denominated in another currency, the Dollar-equivalent principal amount
         of such Indebtedness Incurred pursuant thereto


<PAGE>
                                       52


         shall be calculated based on the relevant currency exchange rate in
         effect on the date that such Indebtedness was Incurred (or, in the case
         of Indebtedness under a revolving credit facility, at the time of
         commitment), PROVIDED that if such Indebtedness is Incurred to
         refinance other Indebtedness denominated in a foreign currency, and
         such refinancing would cause the applicable Dollar-denominated
         restriction to be exceeded if calculated at the relevant currency
         exchange rate in effect on the date of such refinancing, such
         Dollar-denominated restriction shall be deemed not to have been
         exceeded so long as the principal amount of such refinancing
         Indebtedness does not exceed the principal amount of such Indebtedness
         being refinanced. The principal amount of any Indebtedness Incurred to
         refinance other Indebtedness, if Incurred in a different currency from
         the Indebtedness being refinanced, shall be calculated based on the
         currency exchange rate applicable to the currencies in which such
         respective Indebtedness is denominated that is in effect on the date of
         such refinancing.

                  (iii) For purposes of determining any particular amount of
         Indebtedness under this Section 5.02(a), Guarantees, Liens or
         obligations with respect to letters of credit, bankers' acceptances or
         other similar instruments supporting Indebtedness otherwise included in
         the determination of such particular amount shall not be included. For
         purposes of determining compliance with this 5.02(a), (1) any other
         obligation of the obligor on such Indebtedness arising under any Lien
         or letter of credit, bankers' acceptance or other similar instrument or
         obligation supporting such Indebtedness shall be disregarded to the
         extent that the same secures the principal amount of such Indebtedness
         and (2) in the event that an item of Indebtedness meets the criteria of
         more than one of the types of Indebtedness described in the above
         clauses, the Parent, in its sole discretion, shall classify, and from
         time to time may reclassify, such item of Indebtedness and only be
         required to include the amount and type of such Indebtedness in one of
         such clauses (but may allocate portions of such Indebtedness between or
         among such clauses).

                  (b)  RESTRICTED PAYMENTS.  (i) Directly or indirectly,

                           (A) declare or pay any dividend or make any
                  distribution on or with respect to its Capital Stock (other
                  than (x) dividends or distributions payable solely in shares
                  of its Capital Stock (other than Disqualified Stock) or in
                  options, warrants or other rights to acquire shares of such
                  Capital Stock and (y) dividends or distributions on Capital
                  Stock of a Restricted Subsidiary held by minority interest
                  holders on no more than a pro rata basis, measured by value
                  and based on all outstanding Capital Stock of such Restricted
                  Subsidiary) held by Persons other than the Parent or any of
                  its Restricted Subsidiaries;

                           (B) purchase, redeem, retire or otherwise acquire for
                  value any shares of Capital Stock of (x) the Parent or an
                  Unrestricted Subsidiary (including options, warrants or other
                  rights to acquire such shares of Capital Stock) held by any
                  Person other than the Parent or any Wholly Owned Restricted
                  Subsidiary or (y) a Restricted Subsidiary (including options,
                  warrants or other rights to acquire such shares of Capital
                  Stock) held by any


<PAGE>
                                       53


                  Affiliate of the Parent (other than a Wholly Owned Restricted
                  Subsidiary) or any holder (or any Affiliate of such holder) of
                  5% or more of the Capital Stock of the Parent;

                           (C) make any voluntary or optional principal payment,
                  or voluntary or optional redemption, repurchase, defeasance,
                  or other acquisition or retirement for value, of (i)
                  Indebtedness of the Parent or (ii) Indebtedness of any
                  Restricted Subsidiary that is expressly subordinated in right
                  of payment to the Advances; or

                           (D) make any Investment, other than a Permitted
                  Investment, in any other Person (such payments or any other
                  actions described in clauses (A) through (D) above being
                  collectively "RESTRICTED PAYMENTS"),

         if, at the time of, and after giving effect to, the proposed Restricted
         Payment: (I) a Default or Event of Default shall have occurred and be
         continuing , (II) the Parent could not Incur at least $1.00 of
         Indebtedness under Section 5.02(a)(i) hereof or (III) the aggregate
         amount of all Restricted Payments (the amount, if other than in cash,
         to be determined in good faith by the Board of Directors, whose
         determination shall be conclusive and evidenced by a Board Resolution)
         made after the Closing Date shall exceed the sum of (1) 50% of the
         aggregate amount of the Adjusted Consolidated Net Income (or, if the
         Adjusted Consolidated Net Income is a loss, minus 100% of the amount of
         such loss) accrued on a cumulative basis during the period (taken as
         one accounting period) beginning on the first day of the fiscal quarter
         beginning immediately following the Closing Date and ending on the last
         day of the last fiscal quarter preceding the Transaction Date for which
         reports have been filed with the Commission or provided to the
         Administrative Agent PLUS (2) the aggregate Net Cash Proceeds received
         by the Parent after the Closing Date as a capital contribution or from
         the issuance and sale permitted by this Agreement of its Capital Stock
         (other than Disqualified Stock) to a Person who is not a Subsidiary of
         the Parent, including the proceeds of an issuance or sale permitted by
         this Agreement of Indebtedness of the Parent for cash subsequent to the
         Closing Date upon the conversion of such Indebtedness into Capital
         Stock (other than Disqualified Stock) of the Parent, or from the
         issuance to a Person who is not a Subsidiary of the Parent of any
         options, warrants or other rights to acquire Capital Stock of the
         Parent (in each case, exclusive of any Disqualified Stock or any
         options, warrants or other rights that are redeemable at the option of
         the holder, or are required to be redeemed, prior to the Stated
         Maturity of the Advances), in each case except to the extent such Net
         Cash Proceeds are used to Incur Indebtedness pursuant to Section
         5.02(a)(i)(G) PLUS (3) an amount equal to the net reduction in
         Investments (other than reductions in Permitted Investments and
         Investments under Section 5.02(b)(ii)(F), (H) or (L) in any Person
         resulting from payments of interest on Indebtedness, dividends,
         distributions, repayments of loans or advances, or other transfers of
         assets, in each case to the Parent or any Restricted Subsidiary or from
         the Net Cash Proceeds from the sale or other disposition of any such
         Investment (except, in each case, to the extent of any gain on such
         sale or other disposition that would be included in the calculation of
         Adjusted Consolidated Net


<PAGE>
                                       54


         Income for purposes of clause (III)(1) above), or from redesignations
         of Unrestricted Subsidiaries as Restricted Subsidiaries (valued in each
         case as provided in the definition of "INVESTMENTS"), not to exceed, in
         each case, the amount of Investments previously made by the Parent or
         any Restricted Subsidiary in such Person or Unrestricted Subsidiary.

                  (ii) The foregoing provision shall not be violated by reason
         of:

                           (A) the payment of any dividend within 60 days after
                  the date of declaration thereof if, at said date of
                  declaration, such payment would comply with the foregoing
                  paragraph;

                           (B) [Intentionally omitted];

                           (C) the repurchase, redemption or other acquisition
                  of Capital Stock of the Parent or any Subsidiary of the Parent
                  (or options, warrants or other rights to acquire such Capital
                  Stock) in exchange for, or out of the proceeds of a capital
                  contribution or a substantially concurrent offering of, shares
                  of Capital Stock (other than Disqualified Stock) of the Parent
                  (or options, warrants or other rights to acquire such Capital
                  Stock);

                           (D) the making of any principal payment on or the
                  repurchase, redemption, retirement, defeasance or other
                  acquisition for value of Indebtedness of the Parent which is
                  subordinated in right of payment to the Advances in exchange
                  for, or out of the proceeds of a capital contribution or a
                  substantially concurrent offering of, shares of the Capital
                  Stock (other than Disqualified Stock) of the Parent (or
                  options, warrants or other rights to acquire such Capital
                  Stock);

                           (E) payments or distributions to dissenting
                  shareholders pursuant to applicable law, pursuant to or in
                  connection with a consolidation, merger or transfer of assets
                  that complies with the provisions of Section 5.02(j) hereof;

                           (F) any Investment in any Person the primary business
                  of which is related, ancillary or complementary to the
                  business of the Parent and its Restricted Subsidiaries on the
                  date of such Investment; PROVIDED that the aggregate amount of
                  Investments made pursuant to this clause (F) does not exceed
                  the sum of (a) $25 million, plus (b) the amount of Net Cash
                  Proceeds received by the Parent after the Closing Date as a
                  capital contribution or from the sale of its Capital Stock
                  (other than Disqualified Stock) to a Person who is not a
                  Subsidiary of the Parent, except to the extent such Net Cash
                  Proceeds are used to Incur Indebtedness pursuant to Section
                  5.02(a)(i)(G) or to make Restricted Payments pursuant to
                  Section 5.02(b)(i)(III)(2) or Section 5.02(b)(ii)(C), (D) or
                  (J), plus (c) the net reduction in Investments made pursuant
                  to this clause (F) resulting from distributions on or
                  repayments of such Investments or from the Net Cash Proceeds
                  from the sale or other disposition


<PAGE>
                                       55


                  of any such Investment (except in each case to the extent of
                  any gain on such sale or other disposition that would be
                  included in the calculation of Adjusted Consolidated Net
                  Income for purposes of Section 5.02(b)(i)(III)(1) above) or
                  from such Person becoming a Restricted Subsidiary (valued in
                  each case as provided in the definition of "INVESTMENTS"),
                  PROVIDED that the net reduction in any Investment shall not
                  exceed the amount of such Investment;

                           (G) Investments acquired as a capital contribution to
                  or in exchange for Capital Stock (other than Disqualified
                  Stock) of the Parent;

                           (H) Investments in Permitted Joint Ventures not
                  exceeding, at the time of the Investment, the sum of (A) $10
                  million and (B) the net reduction in Investments made pursuant
                  to this clause (H) resulting from distributions on or
                  repayments of such Investments or from the Net Cash Proceeds
                  from the sale or other disposition of any such Investment
                  (except in each case to the extent of any gain on such sale or
                  disposition that would be included in the calculation of
                  Adjusted Consolidated Net Income for purposes of Section
                  5.02(b)(i)(III)(1) above) or from such Person becoming a
                  Restricted Subsidiary (valued in each case as provided in the
                  definition of "INVESTMENTS"), PROVIDED that the net reduction
                  in any Investment shall not exceed the amount of such
                  Investment;

                           (I) repurchases of Warrants by the Parent pursuant to
                  a repurchase offer or within ten days of their expiration in
                  accordance with the terms of the Warrant Agreements in effect
                  on the Closing Date, and any purchase by the Parent of any
                  fractional shares of Common Stock (or other Capital Stock of
                  the Parent issuable upon exercise of the Warrants) in
                  connection with an exercise of the Warrants and any payments
                  in connection with the anti-dilution provisions of the Warrant
                  Agreements;

                           (J) the purchase, redemption, retirement or other
                  acquisition for value by the Parent of shares of Capital Stock
                  of the Parent or options, warrants or other rights to purchase
                  such shares held by Management Investors upon death,
                  disability, retirement, termination of employment or pursuant
                  to the terms of any agreement under which such shares of
                  Capital Stock or options, warrants or other rights were
                  issued; PROVIDED that the aggregate consideration paid for
                  such purchase, redemption, retirement or other acquisition for
                  value of such shares or options, warrants or other rights
                  after the Closing Date does not in the aggregate exceed (A) $5
                  million, plus (B) the aggregate Net Cash Proceeds received by
                  the Parent after the Closing Date as a capital contribution
                  from, or from the issuance or sale to, Management Investors of
                  Capital Stock of the Parent or any options, warrants or other
                  rights to acquire such Capital Stock, plus (C) the proceeds of
                  insurance policies used to effect any such purchase,
                  redemption, retirement or other acquisition;

                           (K) any purchase, redemption, retirement or other
                  acquisition of Capital Stock deemed to occur upon the exercise
                  of options, warrants or other


<PAGE>
                                       56


                  rights if such Capital Stock represents a portion of the
                  exercise price thereof; or

                           (L) other Restricted Payments in an aggregate amount
                  not to exceed $5 million plus the net reduction in Investments
                  made pursuant to this clause (xii) resulting from
                  distributions on or repayments of such Investments or from the
                  Net Cash Proceeds from the sale or other disposition of any
                  such Investment (except in each case to the extent of any gain
                  on such sale or disposition that would be included in the
                  calculation of Adjusted Consolidated Net Income for purposes
                  of clause (III)(1) of clause (i) of Section 5.02(b) above) or
                  from such Person becoming a Restricted Subsidiary (valued in
                  each case as provided in the definition of "Investments"),
                  PROVIDED that the net reduction in any Investment shall not
                  exceed the amount of such Investment;

         PROVIDED that, except in the case of Sections 5.02(b)(ii)(A), (C) or
         (K), no Default or Event of Default shall have occurred and be
         continuing or occur as a consequence of the actions or payments set
         forth therein.

                  Each Restricted Payment permitted pursuant to the preceding
         paragraph (other than the Restricted Payment referred to in clause (B)
         thereof, an exchange of Capital Stock for Capital Stock or Indebtedness
         referred to in clause (C) or (D) thereof, an Investment referred to in
         clause (G) thereof and a purchase, redemption, retirement or other
         acquisition of Capital Stock referred to in clause (K) thereof), and
         the Net Cash Proceeds from any capital contribution or any issuance of
         Capital Stock referred to in clauses (C), (D) and (F) thereof, shall be
         included in calculating whether the conditions of Section
         5.02(b)(i)(III) have been met with respect to any subsequent Restricted
         Payments.

                  (c) DIVIDEND AND OTHER PAYMENT RESTRICTIONS AFFECTING
         RESTRICTED SUBSIDIARIES. Create or otherwise cause or suffer to exist
         or become effective any consensual encumbrance or restriction of any
         kind on the ability of any Restricted Subsidiary to (i) pay dividends
         or make any other distributions permitted by applicable law on any
         Capital Stock of such Restricted Subsidiary owned by the Parent or any
         other Restricted Subsidiary, (ii) pay any Indebtedness owed to the
         Parent or any other Restricted Subsidiary, (iii) make loans or advances
         to the Parent or any other Restricted Subsidiary or (iv) transfer any
         of its property or assets to the Parent or any other Restricted
         Subsidiary, other than any encumbrances or restrictions:

                           (A) existing on the Closing Date, including under the
                  Loan Documents, the Indentures or any other agreements or
                  instruments in effect on the Closing Date, and any
                  refinancings of such agreements or instruments; PROVIDED that
                  the encumbrances and restrictions in any such refinancings are
                  no less favorable in any material respect to the Lenders than
                  those encumbrances or restrictions that are then in effect and
                  that are being refinanced;

<PAGE>
                                       57


                           (B) existing under or by reason of applicable law or
                  any requirement of any applicable governmental regulatory
                  authority;

                           (C) existing with respect to any Person, or any
                  property or assets, acquired by the Parent or any Restricted
                  Subsidiary, existing at the time of such acquisition and not
                  incurred in contemplation thereof, which encumbrances or
                  restrictions are not applicable (A) in the case of an
                  acquisition of such Person to any other Person or (B) in the
                  case of an acquisition of such property or assets any other
                  property or assets;

                           (D) in the case of clause (iv) above (and, solely
                  with respect to clauses (w), (x) and (z) of this clause (D),
                  clause (i) above), (w) that restrict in a customary manner the
                  subletting, assignment or transfer of any property or asset
                  that is, or is subject to, a lease, license, conveyance or
                  contract or similar property or asset, (x) existing by virtue
                  of any transfer of, agreement to transfer, option or right
                  with respect to, or Lien on, any property or assets of the
                  Parent or any Restricted Subsidiary not otherwise prohibited
                  by this Agreement, (y) arising or agreed to in the ordinary
                  course of business, not relating to any Indebtedness, and that
                  do not, individually or in the aggregate, detract from the
                  value of property or assets of the Parent or any Restricted
                  Subsidiary in any manner material to the Parent or any
                  Restricted Subsidiary or (z) arising under the terms of
                  Indebtedness Incurred under Section 5.02(a)(i)(F) that
                  restrict the transfer of the property or assets acquired with
                  such Indebtedness;

                           (E) with respect to a Restricted Subsidiary and
                  imposed pursuant to an agreement that has been entered into
                  for the sale or disposition of all or substantially all of the
                  Capital Stock of, or property and assets of, such Restricted
                  Subsidiary;

                           (F) contained in the terms of any Indebtedness or any
                  agreement pursuant to which such Indebtedness was issued, or
                  any agreement relating to the sale, disposition or financing
                  of receivables, if (x) either (1) the encumbrance or
                  restriction applies only in the event of a payment default or
                  a default with respect to a financial covenant contained in
                  the terms of such Indebtedness or agreement or (2) the Parent
                  in good faith determines (as set forth in a Board Resolution)
                  that any such encumbrance or restriction will not materially
                  affect the Parent's ability to make principal or interest
                  payments on the Advances and (y) the encumbrance or
                  restriction is not materially more disadvantageous to the
                  Lenders than is customary in comparable financings (as
                  determined by the Parent in good faith);

                           (G) restrictions on cash or other deposits or net
                  worth imposed by customers under contracts entered into in the
                  ordinary course of business; or

                           (H) customary provisions in joint venture agreements
                  and other similar agreements entered into in the ordinary
                  course of business.

<PAGE>
                                       58


         Nothing contained in this Section 5.02(c) shall prevent the Parent or
         any Restricted Subsidiary from (x) creating, incurring, assuming or
         suffering to exist any Liens otherwise permitted under Section 5.02(g)
         or (y) restricting the sale or other disposition of property or assets
         of the Parent or any of its Restricted Subsidiaries that secure
         Indebtedness of the Parent or any of its Restricted Subsidiaries.

                  (d) ISSUANCE AND SALE OF CAPITAL STOCK OF RESTRICTED
         SUBSIDIARIES. Issue or sell any shares of Capital Stock of a Restricted
         Subsidiary (including options, warrants or other rights to purchase
         shares of such Capital Stock) except:

                           (i)  to the Parent or a Wholly Owned Restricted
                  Subsidiary;

                           (ii) issuances of director's qualifying shares or
                  issuances or sales to foreign nationals of shares of Capital
                  Stock of foreign Restricted Subsidiaries, to the extent
                  required by applicable law;

                           (iii) if, immediately after giving effect to such
                  issuance or sale, such Restricted Subsidiary would no longer
                  constitute a Restricted Subsidiary and any Investment in such
                  Person remaining after giving effect to such issuance or sale
                  would have been permitted to be made under Section 5.02(b) if
                  made on the date of such issuance or sale; or

                           (iv) issuances or sales of Common Stock of a
                  Restricted Subsidiary; PROVIDED that the Parent or such
                  Restricted Subsidiary applies the Net Cash Proceeds, if any,
                  of any such issuance or sale to prepay the Advances to the
                  extent required by Section 2.08(b) hereof.

                  (e) ISSUANCES OF GUARANTEES BY RESTRICTED SUBSIDIARIES. Allow
         any Restricted Subsidiary to Guarantee (x) the High Yield Notes or any
         other Indebtedness of the Parent (other than any such Indebtedness
         indirectly arising (through subrogation or otherwise) as a result of a
         Guarantee by the Parent of Indebtedness of a Restricted Subsidiary,
         which Indebtedness of such Restricted Subsidiary is otherwise permitted
         under this Agreement) or (y) any Permitted Intercompany Indebtedness or
         any other Indebtedness of any Subsidiary Guarantor which is PARI PASSU
         with or expressly subordinate in right of payment to the Advances
         ("GUARANTEED INDEBTEDNESS"), unless, in the case of a Guarantee by a
         Restricted Subsidiary of Indebtedness of a Subsidiary Guarantor, (i)
         such Restricted Subsidiary simultaneously executes and delivers a
         supplemental guarantee to this Agreement providing for a Guarantee (a
         "SUBSIDIARY GUARANTEE") of payment of the Advances by such Restricted
         Subsidiary and (ii) such Restricted Subsidiary waives and will not in
         any manner whatsoever claim or take the benefit or advantage of, any
         rights of reimbursement, indemnity or subrogation or any other rights
         against the Parent or any other Restricted Subsidiary as a result of
         any payment by such Restricted Subsidiary under its Subsidiary
         Guarantee; PROVIDED that this paragraph shall not be applicable to any
         Guarantee of any Restricted Subsidiary (a) that existed at the time
         such Person became a Restricted Subsidiary and was not


<PAGE>
                                       59


         Incurred in connection with, or in contemplation of, such Person
         becoming a Restricted Subsidiary or (b) of Indebtedness Incurred
         pursuant to Section 5.02(a)(i)(A). If the Guaranteed Indebtedness is
         (A) PARI PASSU with the Advances, then the Guarantee of such Guaranteed
         Indebtedness shall be PARI PASSU with, or subordinated to, the
         Subsidiary Guarantee or (B) subordinated to the Advances, then the
         Guarantee of such Guaranteed Indebtedness shall be subordinated to the
         Subsidiary Guarantee at least to the extent that the Guaranteed
         Indebtedness is subordinated to the Advances.

                  (f) TRANSACTIONS WITH SHAREHOLDERS AND AFFILIATES. (i) Enter
         into, renew or extend any transaction (including, without limitation,
         the purchase, sale, lease or exchange of property or assets, or the
         rendering of any service) with any holder (or any Affiliate of such
         holder) of 5% or more of any class of Capital Stock of the Parent or
         with any Affiliate of the Parent or any Restricted Subsidiary, except
         upon fair and reasonable terms that taken as a whole are no less
         favorable to the Parent and such Restricted Subsidiary than could be
         obtained, at the time of such transaction or, if such transaction is
         pursuant to a written agreement, at the time of the execution of the
         agreement providing therefor, in a comparable arm's-length transaction
         with a Person that is not such a holder or an Affiliate.

                  (ii) The foregoing limitation does not limit, and shall not
         apply to:

                           (A) transactions (x) approved by a majority of the
                  disinterested members of the Board of Directors or (y) for
                  which the Parent or a Restricted Subsidiary delivers to the
                  Administrative Agent a written opinion of a nationally
                  recognized investment banking firm stating that the
                  transaction is fair to the Parent (in a transaction not
                  involving a Restricted Subsidiary) or such Restricted
                  Subsidiary from a financial point of view, or is upon terms
                  that taken as a whole are no less favorable to the Parent (in
                  a transaction not involving a Restricted Subsidiary) or such
                  Restricted Subsidiary than could be obtained in a comparable
                  arm's-length transaction;

                           (B) any transaction solely between or among the
                  Parent and any of its Wholly Owned Restricted Subsidiaries to
                  the extent such transactions are in the ordinary course of
                  business or solely between or among between Wholly Owned
                  Restricted Subsidiaries;

                           (C) the payment of reasonable and customary regular
                  fees to directors of the Parent who are not employees of the
                  Parent;

                           (D) any payments or other transactions pursuant to
                  any tax-sharing agreement between the Parent and any other
                  Person with which the Parent files a consolidated tax return
                  or with which the Parent is part of a consolidated group for
                  tax purposes; or

                           (E) any Restricted Payments (or a transaction
                  excluded from the definition of the term "RESTRICTED
                  PAYMENTS") not prohibited by Section 5.02(b).

<PAGE>
                                       60


                           (F) transactions consisting of or pursuant to
                  employment or benefit agreements, plans, programs or
                  arrangements for or with, or indemnification or contribution
                  obligations to, employees, officers or directors in the
                  ordinary course of business;

                           (G) the entering into of the Securities Purchase and
                  Cancellation Agreement, the 1999 Share Option Plan, the
                  Securities Purchase Agreement, the Registration Rights
                  Agreement and the Securityholders' Agreement, as described in
                  the Offering Memorandum dated February 12, 1999 as amended or
                  supplemented, and performance of the obligations and the
                  transactions contemplated thereby; or

                           (H) issuances or sales of Capital Stock (other than
                  Disqualified Stock) of the Parent or options, warrants or
                  other rights to acquire such Capital Stock.

                  (iii) Notwithstanding the foregoing, any transaction or series
         of related transactions covered by paragraph (i) above and not covered
         by clauses (B) through (H) of paragraph (ii), the aggregate amount of
         which exceeds $2 million in value, must be approved or determined to be
         fair in the manner provided for in clause (A)(x) or (y) above.

                  (g) LIENS. Create, incur, assume or suffer to exist any Lien
         on any of its assets or properties of any character (including, without
         limitation, licenses), or any shares of Capital Stock or Indebtedness
         of any Restricted Subsidiary, other than:

                           (i)  Liens existing on the Closing Date;

                           (ii) Liens granted on or after the Closing Date on
                  any assets or Capital Stock of the Parent or its Restricted
                  Subsidiaries created in favor of the Lenders;

                           (iii) Liens with respect to the assets of a
                  Restricted Subsidiary granted by such Restricted Subsidiary to
                  a Wholly Owned Restricted Subsidiary to secure Indebtedness
                  owing to such other Restricted Subsidiary;

                           (iv) Liens securing Indebtedness which is permitted
                  to be Incurred under Section 5.02(a)(i)(C) to refinance
                  secured Indebtedness; PROVIDED, that such Liens do not extend
                  to or cover any property or assets of the Parent or any
                  Restricted Subsidiary other than the property or assets
                  securing the Indebtedness being refinanced;

                           (v)   [Intentionally omitted]; or

                           (vi)  Permitted Liens.

<PAGE>
                                       61


                  (h) SALE-LEASEBACK TRANSACTIONS. Enter into any sale-leaseback
         transaction involving any of its assets or properties whether now owned
         or hereafter acquired, whereby the Parent or a Restricted Subsidiary
         sells or transfers such assets or properties more than one year after
         acquiring such assets or properties and then or thereafter leases such
         assets or properties or any part thereof or any other assets or
         properties which the Parent or such Restricted Subsidiary, as the case
         may be, intends to use for substantially the same purpose or purposes
         as the assets or properties sold or transferred, other than any
         sale-leaseback transaction if (i) the lease is for a period, including
         renewal rights, of not in excess of three years; (ii) the lease secures
         or relates to industrial revenue or pollution control bonds; or (iii)
         the transaction is solely between the Parent and any Wholly Owned
         Restricted Subsidiary or solely between Wholly Owned Restricted
         Subsidiaries; PROVIDED, THAT the Parent or such Restricted Subsidiary
         applies an amount not less than the Net Cash Proceeds received from
         such sale to prepay the Advances to the extent required by Section
         2.08(b) hereof.

                  (i)  ASSET SALES.  Consummate any Asset Sale, unless

                           (i) the consideration received by the Parent or such
                  Restricted Subsidiary (including any Released Indebtedness and
                  including by way of relief from or by any other Person
                  assuming responsibilities for any liabilities other than
                  Indebtedness ("RELEASED LIABILITIES")) is at least equal to
                  the fair market value of the assets sold or disposed of;
                  PROVIDED that this clause (i) shall not apply to any sale,
                  transfer or other disposition arising from foreclosure,
                  condemnation or similar action with respect to any assets; and

                           (ii) at least 75% of the consideration received
                  (including any Released Indebtedness and Released Liabilities)
                  consists of cash, Temporary Cash Investments or Released
                  Indebtedness and Released Liabilities; PROVIDED, HOWEVER, that
                  this clause (ii) shall not apply to long-term assignments in
                  capacity in a telecommunications network or other transfers of
                  indefeasible rights of use, multiple investment units or dark
                  fibers;

                  PROVIDED, that, the Parent shall or shall cause the relevant
                  Restricted Subsidiary to apply the Net Cash Proceeds of such
                  Asset Sale to prepay the Advances to the extent required by
                  Section 2.08(b) hereof:

                  (j) MERGERS, CONSOLIDATIONS, ETC. Consolidate with, merge with
         or into, or sell, convey, transfer, lease or otherwise dispose of all
         or substantially all of its property and assets (as an entirety or
         substantially an entirety in one transaction or a series of related
         transactions) to, any Person or permit any Person to merge with or into
         the Parent unless:

                           (i) the Parent shall be the continuing Person, or the
                  Person (if other than the Parent) formed by such consolidation
                  or into which the Parent is merged or that acquired or leased
                  such property and assets of the Parent shall be a corporation
                  organized and validly existing under the laws of the Kingdom



<PAGE>
                                       62


                  of the Netherlands (including the Netherlands Antilles),
                  Bermuda, Canada, Switzerland, any member state of the European
                  Union or the United States of America or any jurisdiction
                  thereof;

                           (ii) immediately after giving effect to such
                  transaction, no Default or Event of Default shall have
                  occurred and be continuing;

                           (iii) immediately after giving effect to such
                  transaction on a pro forma basis, the Parent or any such
                  Person shall have a Consolidated Net Worth equal to or greater
                  than the Consolidated Net Worth of the Parent immediately
                  prior to such transaction; PROVIDED that this clause (iii)
                  shall only apply to a sale of less than all of the assets of
                  the Parent;

                           (iv) immediately after giving effect to such
                  transaction on a pro forma basis the Parent, or any such
                  Person, as the case may be, could Incur at least $1.00 of
                  Indebtedness under Section 5.02(a)(i) hereof; PROVIDED that
                  this clause (iv) shall not apply to a consolidation, merger or
                  sale of all (but not less than all) of the assets of the
                  Parent if all Liens and Indebtedness of the Parent or any such
                  Person, as the case may be, and its Restricted Subsidiaries
                  outstanding immediately after such transaction would, if
                  Incurred at such time, have been permitted to be Incurred (and
                  all such Liens and Indebtedness, other than Liens and
                  Indebtedness of the Parent and its Restricted Subsidiaries
                  outstanding immediately prior to the transaction, shall be
                  deemed to have been Incurred) for all purposes of this
                  Agreement; and

                           (v) the Parent delivers to the Administrative Agent
                  an officers' certificate (attaching the arithmetic
                  computations to demonstrate compliance with clauses (iii) and
                  (iv) above) to the effect that such consolidation, merger or
                  transfer complies with this provision and that all conditions
                  precedent provided for in this paragraph relating to such
                  transaction have been complied with;

         PROVIDED, HOWEVER, that clauses (iii) and (iv) above will not apply if,
         in the good faith determination of the Board of Directors of the
         Parent, whose determination shall be evidenced by a Board Resolution,
         the principal purpose of such transaction is to change the jurisdiction
         of organization of the Parent, and such transaction does not have as
         one of its purposes the evasion of the foregoing limitations.

                  (k) NEGATIVE PLEDGE. Enter into or suffer to exist any
         agreement prohibiting or conditioning the creation or assumption of any
         Lien upon any of its property or assets other than an agreement in
         favor of the Security Agent and the Lenders.

                  (l) PREPAYMENTS, ETC. OF INDEBTEDNESS. Prepay, redeem,
         purchase, defease or otherwise satisfy prior to the scheduled maturity
         thereof in any manner the High Yield Notes or any Permitted
         Intercompany Indebtedness or amend, modify or change in any manner any
         term or condition of the High Yield Notes or any Permitted


<PAGE>
                                       63


         Intercompany Indebtedness to increase the amount payable (in the case
         of the High Yield Notes only) or accelerate the time of payment
         thereunder.

                  (m) BOOK VALUE OF ASSETS. Permit any director, officer or
         employee of the Parent or any of its Restricted Subsidiaries with
         actual knowledge of Section 5.01(i) hereof to make any voluntary or
         optional payment or any acquisition or disposition of assets that would
         reasonably be expected at the end of the current quarter to cause the
         combined book value of the assets (other than cash, cash equivalents
         and restricted investments) of the Guarantors at the end of the current
         quarter to be less than 80% of the Consolidated book value of the
         assets (other than cash, cash equivalents and restricted investments)
         of the Parent and its Subsidiaries taken as a whole.

         SECTION 5.03. FINANCIAL COVENANT. So long as any Advance shall remain
unpaid or any Lender shall have any Commitment hereunder, the Parent will
maintain, as of the end of each quarter, Consolidated EBITDA of the Parent and
its Subsidiaries for the quarter then ended of not less than the amount set
forth below for such quarter:

<TABLE>
<CAPTION>

                    Quarter                                    Minimum
                 Ending On                             Consolidated EBITDA
                 ---------                             -------------------

                 <S>                                   <C>
                 March 31, 2000                        -$16.2 million

                 June 30, 2000                         -$12.2 million

                 September 30, 2000                    -$7.8 million

</TABLE>

         SECTION 5.04.  LIMITATION ON PARENT ACTIVITIES.  So long as any Advance
shall remain unpaid or any Lender shall have any Commitment hereunder,
notwithstanding anything to the contrary in this Agreement or any other Loan
document, the Parent will not

                  (a) conduct, transact or otherwise engage in, or commit to
         conduct, transact or otherwise engage in, any business or operations
         other than (i) the provisions of administrative, legal, accounting and
         management services to or on behalf of any of its Subsidiaries, (ii)
         those incidental to its ownership of the Capital Stock of the Borrowers
         or other ownership interests in its Subsidiaries (to the extent not
         otherwise prohibited by this Agreement), and the exercise of rights and
         performance of obligations in connection therewith, (iii) the entry
         into, and exercise of rights and performance of obligations in respect
         of, (A) this Agreement and any other Loan Document to which the Parent
         is a party, and any Indebtedness or other obligations permitted
         pursuant to this Agreement and such other Loan Documents, in each case
         as amended, supplemented, waived or otherwise modified from time to
         time, and any refinancings, refundings, renewals or extensions thereof,
         (B) contracts and agreement with officers, directors and employees of
         the Parent or a Subsidiary thereof relating to their employment or
         directorships, (C) insurance policies and related contracts and
         agreements, and (D) equity subscription agreements, registration rights
         agreements,


<PAGE>
                                       64


         voting and other stockholder agreements, engagement letters,
         underwriting agreements and other agreements in respect of its equity
         securities or any offering, issuance or sale thereof, including but not
         limited to in respect of purchases of equity by Management Investors,
         (iv) the offering, issuance, sale and repurchase or redemption of, and
         dividends or distributions on, its equity securities, (v) the filing of
         registration statements, and compliance with applicable reporting and
         other obligations, under federal, state or other securities laws, (vi)
         the listing of its equity securities and its High Yield Notes and
         compliance with applicable reporting and other obligations in
         connection therewith, (vii) the retention of (and entry into, and
         exercise of rights and performance of obligations in respect of,
         contracts and agreements with) transfer agents, private placement
         agents, underwriters, counsel, accountants and other advisors and
         consultants, (viii) the performance of obligations under and compliance
         with the requirements of its certificate of incorporation and by-laws
         or other organizational documents, or any applicable law, ordinance,
         regulation, rule, order, judgment, decree or permit, including without
         limitation, as a result of or in connection with the activities of its
         Subsidiaries, (ix) the incurrence and payment of its operating and
         business expenses and any taxes for which it may be liable, (x) making
         loans constituting Permitted Intercompany Indebtedness to or other
         Investments constituting Capital Stock in, or incurrence of
         Indebtedness in respect of advances in the ordinary course of business
         to, its Restricted Subsidiaries, (xi) the ownership of, and exercise of
         rights and performance of obligations in respect of, patents,
         trademarks, trade names, copyrights, technology, know-how and processes
         and licensing of such patents, trademarks, trade names, copyrights,
         technology, know-how and processes (other than such patents,
         trademarks, trade names, copyrights, technology, know-how and processes
         which are material to the business of the Borrowers, which shall be
         owned by the Borrowers and their respective Restricted Subsidiaries)
         and (vii) other activities incidental or reasonably related to the
         foregoing;

                  (b) Incur any Indebtedness or other liabilities or financial
         obligations, except (i) nonconsensual obligations imposed by operation
         of law, (ii) pursuant to this Agreement and the other Loan Documents to
         which it is a party or as permitted by Section 5.04(a) hereof, (iii)
         pursuant to the Indentures and the High Yield Notes, (iv) pursuant to
         the Nortel Facility and the security and other arrangements related
         thereto, (v) pursuant to the German L/C and obligations in respect
         thereof and (vi) obligations with respect to its Capital Stock.

                                   ARTICLE VI

                                EVENTS OF DEFAULT

                  SECTION 6.01.  EVENTS OF DEFAULT. If any of the following
events ("EVENTS OF DEFAULT") shall occur and be continuing:

                  (a) default in the payment of principal of any Advance when
         the same becomes due and payable at maturity, upon acceleration,
         redemption or otherwise;

<PAGE>
                                       65


                  (b) default in the payment of interest on any Advance when the
         same becomes due and payable, and such default continues for a period
         of 5 Business Days;

                  (c) failure to pay any other amount which is due to be paid
         under any Loan Documents and such default continues for a period of 5
         Business Days;

                  (d) default in the performance or breach of the provisions of
         Section 5.02(a), (b), (f), (g) or (j) hereof;

                  (e) any Loan Party defaults in the performance of or breaches
         any other covenant or agreement of such Loan Party in the Loan
         Documents (other than a default specified in clause (a), (b) (c) or (d)
         above) and such default or breach continues for a period of 30
         consecutive days after written notice by the Administrative Agent;

                  (f) any representations or warranty made by any Loan Party
         under or pursuant to any Loan Document proving to be untrue in any
         material respect when made;

                  (g) the Parent or any of its Restricted Subsidiaries shall
         fail to pay any principal of or premium or interest on any uncontested
         Indebtedness that is outstanding in a principal amount of at least $5
         million in the aggregate (but excluding Indebtedness outstanding
         hereunder) of the Parent or such Restricted Subsidiary (as the case may
         be), when the same becomes due and payable (whether by scheduled
         maturity, required prepayment, acceleration, demand or otherwise), and
         such failure shall continue after the applicable grace period, if any,
         specified in the agreement or instrument relating to such Indebtedness;
         or any other event shall occur or condition shall exist under any
         agreement or instrument relating to any such Indebtedness and shall
         continue after the applicable grace period, if any, specified in such
         agreement or instrument, if the effect of such event or condition is to
         accelerate, or to permit the acceleration of, the maturity of such
         Indebtedness; or any such Indebtedness shall be declared to be due and
         payable, or required to be prepaid or redeemed (other than by a
         regularly scheduled required prepayment or redemption), purchased or
         defeased, or an offer to prepay, redeem, purchase or decease such
         Indebtedness shall be required to be made, in each case prior to the
         stated maturity thereof;

                  (h) the Parent or any of its Significant Subsidiaries shall
         generally not pay its debts as such debts become due, or shall admit in
         writing its inability to pay its debts generally, or shall make a
         general assignment for the benefit of creditors; or any proceeding
         shall be instituted by or against the Parent or any of its Significant
         Subsidiaries seeking to adjudicate it a bankrupt or insolvent, or
         seeking liquidation, winding up, reorganization, arrangement,
         adjustment, protection, relief, or composition of it or its debts under
         any law relating to bankruptcy, insolvency or reorganization or relief
         or debtors, or seeking the entry of an order for relief or the
         appointment of a receiver , trustee, or other similar official for it
         or for any substantial party of its property and, in the case of any
         such proceeding instituted against it (but not instituted


<PAGE>
                                       66


         by it) that is being diligently contested by it in good faith, either
         such proceeding shall remain undismissed or unstayed for a period of 30
         days or any of the actions sought in such proceeding (including,
         without limitation, the entry of an order for relief against, or the
         appointment of a receiver, trustee, custodian or other similar official
         for, it or any substantial part of its property) shall occur; or the
         Parent or any of its Significant Subsidiaries shall taken any corporate
         action to authorize any of the actions set forth above in this
         subsection; or

                  (i) any final judgment or order (not covered by insurance) for
         the payment of money in excess of $10 million in the aggregate for all
         such final judgments or orders against all such Persons (treating any
         deductibles, self-insurance or retention as not so covered) shall be
         rendered against the Parent or any Significant Subsidiary and shall not
         be paid or discharged, and there shall be any period of 60 consecutive
         days following entry of the final judgment or order that causes the
         aggregate amount for all such final judgments or orders outstanding and
         not paid or discharged against all such Persons to exceed $10 million
         during which a stay of enforcement of such final judgment or order, by
         reason of a pending appeal or otherwise, shall not be in effect; or

                  (j) any Pledge Agreement after delivery thereof pursuant to
         Section 3.02, 3.03 or 5.01(i) shall for any reason (other than pursuant
         to the terms thereof) cease to create a valid and perfected first
         priority lien on and security interest in the collateral purported to
         be covered thereby; or

                  (k) except in each case as would not be reasonably be expected
         to have a Material Adverse Effect, the Parent or any of its ERISA
         Affiliates shall incur, or shall be reasonably likely to incur
         liability as a result of one or more of the following; (i) the
         occurrence of any ERISA Event; (ii) the partial or complete withdrawal
         of the Parent of its ERISA Affiliates from a Multiemployer Plan; or
         (iii) the reorganization or termination of a Multiemployer Plan; or

                  (l) a Change of Control shall have occurred;

then, and in any such event, the Administrative Agent (i) shall at the request,
or may with the consent, of the Required Lenders, by notice to the Parent,
declare the obligation of each Lender to make Advances to be terminated,
whereupon the same shall forthwith terminate, and (ii) shall at the request, or
may with the consent, of the Required Lenders, by notice to the Parent, declare
the Advances, all interest thereon and all other amounts payable under the Loan
Documents to be forthwith due and payable, whereupon the Advances, all such
interest and all such amounts shall become and be forthwith due and payable,
without presentment, demand, protest or further notice of any kind, all of which
are hereby expressly waived by each Loan Party; PROVIDED, HOWEVER, that upon an
Event of Default with respect to the Parent under (h) above, (A) the obligation
of each Lender to make Advances shall automatically be terminated and (B) the
Advances, all such interest and all such amounts shall automatically become and
be due and payable, without presentment, demand, protest or any notice of any
kind, all of which are hereby expressly waived by each Loan Party.


<PAGE>
                                       67


                                   ARTICLE VII

                                   THE AGENTS

                  SECTION 7.01. AUTHORIZATION AND ACTION. Each Lender hereby
appoints and authorizes the Agents to take such action as agent on its behalf
and to exercise such powers and discretion under the Loan Documents as are
delegated to the Agents by the terms hereof and thereof, together with such
powers and discretion as are reasonably incidental thereto. As to any matters
not expressly provided for by the Loan Documents (including, without limitation,
collection of the Advances), the Agents shall not be required to exercise any
discretion or take any action, but shall be required to act or to refrain from
acting (and shall be fully protected in so acting or refraining from acting)
upon the instructions of the Required Lenders, and such instructions shall be
binding upon all Lenders; PROVIDED, HOWEVER, that no Agent shall be required to
take any action that exposes such Agent to personal liability or that is
contrary to the Loan Documents or applicable law. Each Agent agrees to give to
each Lender prompt notice of each notice given to it by the Parent pursuant to
the terms of this Agreement.

                  SECTION 7.02. AGENT'S RELIANCE, ETC. No Agent nor any of its
directors, officers, agents or employees shall be liable for any action taken or
omitted to be taken by it or them under or in connection with the Loan
Documents, except for its or their own gross negligence or willful misconduct.
Without limitation of the generality of the foregoing, each Agent: (i) may
consult with legal counsel (including counsel for any Loan Party), independent
public accountants and other experts selected by it and shall not be liable for
any action taken or omitted to be taken in good faith by it in accordance with
the advice of such counsel, accountants or experts; (ii) makes no warranty or
representation to any Lender and shall not be responsible to any Lender for any
statements, warranties or representations (whether written or oral) made in or
in connection with the Loan Documents; (iii) shall not have any duty to
ascertain or to inquire as to the performance or observance of any of the terms,
covenants or conditions of the Loan Documents on the part of any Loan Party or
to inspect the property (including the books and records) of any Loan Party; (v)
shall not be responsible to any Lender for the due execution, legality,
validity, enforceability, genuineness, sufficiency or value of, or the
perfection or priority of any lien or security interest created or purported to
be created under or in connection with, the Loan Documents or any other
instrument or document furnished pursuant hereto; and (vi) shall incur no
liability under or in respect of the Loan Documents by acting upon any notice,
consent, certificate or other instrument or writing (which may be by telecopier,
telegram or telex) believed by it to be genuine and signed or sent by the proper
party or parties.

                  SECTION 7.03. MSSF AND AFFILIATES. With respect to its
Commitment and the Advances made by it, MSSF shall have the same rights and
powers under the Loan Documents as any other Lender and may exercise the same as
though it were not an Agent; and the term "Lender" or "Lenders" shall, unless
otherwise expressly indicated, include MSSF in its individual capacity. MSSF and
its Affiliates may accept deposits from, lend money to, act as trustee under
indentures of, accept investment banking engagements from and generally


<PAGE>
                                       68


engage in any kind of business with, any Loan Party, any of its Subsidiaries and
any Person who may do business with or own securities of any Loan Party or any
such Subsidiary, all as if MSSF were not an Agent and without any duty to
account therefor to the Lenders.

                  SECTION 7.04. LENDER CREDIT DECISION. Each Lender acknowledges
that it has, independently and without reliance upon any Agent or any other
Lender and based on the financial statements referred to in Section 4.01 hereof
and such other documents and information as it has deemed appropriate, made its
own credit analysis and decision to enter into the Loan Documents. Each Lender
also acknowledges that it will, independently and without reliance upon any
Agent or any other Lender 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 action under the Loan Documents.

                  SECTION 7.05. INDEMNIFICATION. Each Lender severally agrees to
indemnify each Agent (to the extent not reimbursed by the Parent), ratably
according to the respective principal amounts of the Advances then owed to each
of them (or if no Advances are at the time outstanding, ratably according to the
respective amounts of their Commitments), from and against any and all
liabilities, obligations, losses, damages, penalties, actions, judgments, suits,
costs, expenses or disbursements of any kind or nature whatsoever that may be
imposed on, incurred by, or asserted against such Agent in any way relating to
or arising out of this Agreement or any action taken or omitted by such Agent
under the Loan Documents (collectively, the "INDEMNIFIED COSTS"), PROVIDED that
no Lender shall be liable for any portion of the Indemnified Costs resulting
from such Agent's gross negligence or willful misconduct. Without limitation of
the foregoing, each Lender agrees to reimburse each Agent promptly upon demand
for its ratable share of any out-of-pocket expenses (including counsel fees)
incurred by such Agent in connection with the preparation, execution, delivery,
administration, modification, amendment or enforcement (whether through
negotiations, legal proceedings or otherwise) of, or legal advice in respect of
rights or responsibilities under, the Loan Documents, to the extent that such
Agent is not reimbursed for such expenses by the Parent. In the case of any
investigation, litigation or proceeding giving rise to any Indemnified Costs,
this Section 7.05 applies whether any such investigation, litigation or
proceeding is brought by such Agent, any Lender or a third party.

                  SECTION 7.06. SUCCESSOR AGENT. Any Agent may resign at any
time by giving written notice thereof to the Lenders and the Parent. Upon any
such resignation or removal, the Required Lenders shall have the right to
appoint a successor Agent that is, unless a Default has occurred and is
continuing, reasonably acceptable to the Parent. If no successor Agent shall
have been so appointed by the Required Lenders, and shall have accepted such
appointment, within 30 days after the retiring Agent's giving of notice of
resignation, then the retiring Agent may, on behalf of the Lenders, appoint a
successor Agent, which shall be a commercial bank organized under the laws of
the United States of America or of any State thereof and having a combined
capital and surplus of at least $250 million that is, unless a Default has
occurred and is continuing, reasonably acceptable to the Parent. Upon the
acceptance of any appointment as Agent hereunder by a successor Agent, such
successor Agent shall thereupon succeed to and become vested with all the
rights, powers, discretion, privileges and duties of the retiring Agent, and the
retiring Agent shall be discharged from its


<PAGE>
                                       69


duties and obligations under the Loan Documents. After any retiring Agent's
resignation or removal hereunder as Agent, the provisions of this Article VII
shall inure to its benefit as to any actions taken or omitted to be taken by it
while it was Agent under the Loan Documents.

                                  ARTICLE VIII

                                    GUARANTEE

                  SECTION 8.01. GUARANTEE. (a) Except as otherwise set forth
herein, each of the Guarantors hereby unconditionally and irrevocably guarantees
the punctual payment when due, whether at stated maturity, by acceleration or
otherwise, of all obligations of each other Obligor now or hereafter existing
under the Loan Documents, whether for principal, interest, fees, expenses or
otherwise (such obligations being the "GUARANTEED OBLIGATIONS"), and agrees to
pay any and all expenses (including reasonable counsel fees and expenses)
incurred by the Administrative Agent in enforcing any rights hereunder. Without
limiting the generality of the foregoing, the liability of each of the
Guarantors shall extend to all amounts that constitute part of the Guaranteed
Obligations and would be owed by any Obligor to the Administrative Agent under
the Loan Documents but for the fact that they are unenforceable or not allowable
due to the existence of a bankruptcy, reorganization or similar proceeding
involving such Obligor.

                  (b) The liability of each Guarantor organized under the laws
of the Federal Republic of Germany under this Guarantee in respect of the
obligations of any other Person that is not a Subsidiary of such Guarantor shall
not exceed the amount by which, at any time a payment would have to be made by
such Guarantor, the sum of (i) its assets (the calculation of which shall take
into account the captions reflected in Section 266 para. 2, A and B, of the
German Commercial Code - HANDELSGESETZBUCH ("HGB")) exceeds (ii) the sum of (x)
its liabilities (the calculation of which shall take into account the captions
reflected in Section 266 para. 3, B and C, HGB) and (y) its registered share
capital (STAMMKAPITAL). The assets and liabilities of such Guarantor shall be
valued at the respective dates in accordance with German accepted accounting
principles consistently applied. The foregoing limitations shall apply MUTATIS
MUTANDIS with respect to each other legal entity organized under the laws of the
Federal Republic of Germany which becomes liable as a general partner of any
Guarantor under this Guarantee that is a limited partnership
(KOMMANDITGESELLSCHAFT) or general partnership (OFFENE HANDELSGESELLSCHAFT).

                  (c) The liability of each Guarantor organized under the laws
of France in respect of the obligations of any other Person that is not a
Subsidiary of such Guarantor shall not exceed, at any given time a payment would
have to be made by such Guarantor, 95% of such Guarantor's distributable
reserves, defined as the amount by which its equity exceeds the sum of its (i)
share capital, (ii) capital surplus, (iii) legal surplus and (iv) statutory
reserves.

                  (d) The liability of Carrier1 International GmbH arising from
or in connection with the Loan Documents shall not exceed in the aggregate, at
any given time a


<PAGE>
                                       70


payment would have to be made by such Guarantor, 95% of its distributable
reserves, defined as the amount by which the sum of its assets exceeds the sum
of its (i) share capital, (ii) statutory reserves, (iii) legal reserves and (iv)
liabilities in accordance with GAAP including provisions for accrued
liabilities, non-declared transfer pricing, if applicable, and taxes in the
amount of 60% of the amount being guaranteed. Such Guarantee shall further be
limited to an amount the payment of which would be deemed to be in the direct
best interest of Carrier1 International GmbH.

                  (e) The liability of each Acceding Guarantor shall be limited
to the extent necessary to comply with any applicable law dealing with
fraudulent transfers, capital adequacy, financial assistance or similar matters
as set forth in the Accession Agreement pursuant to which such Acceding
Guarantor becomes a party to this Agreement.

                  SECTION 8.02. GUARANTEE ABSOLUTE. Each of the Guarantors
guarantees that the Guaranteed Obligations will be paid strictly in accordance
with the terms of the Loan Documents, regardless of any law, regulation or order
now or hereafter in effect in any jurisdiction affecting any of the terms or the
rights of any Agent with respect thereto. The obligations of each of the
Guarantors under this Guarantee are independent of the Guaranteed Obligations,
and a separate action or actions may be brought and prosecuted against any of
the Guarantors, jointly or individually, to enforce this Guarantee, irrespective
of whether any action is brought against any other Obligor or whether any other
Obligor is joined in any such action or actions. The liability of each of the
Guarantors under this Guarantee shall be joint and several, irrevocable,
absolute and unconditional irrespective of, and each of the Guarantors hereby
irrevocably waives any defenses it may now or hereafter have in any way relating
to, any or all of the following:

                  (a) any lack of validity or enforceability of any Loan
         Document or any agreement or instrument relating hereto;

                  (b) any change in the time, manner or place of payment of, or
         in any other term of, all or any of the Guaranteed Obligations, or any
         other amendment or waiver of or any consent to departure from any Loan
         Document;

                  (c) any taking, release or amendment or waiver of or consent
         to departure from any other guarantee, for all or any of the Guaranteed
         Obligations;

                  (d) any change, restructuring or termination of the corporate
         structure or existence of any Obligor or any of its respective
         Subsidiaries; or

                  (e) any other circumstance (including, without limitation, any
         statute of limitations) or any existence of or reliance on any
         representation by any Agent that might otherwise constitute a defense
         (other than the defense of payment) available to, or a discharge of any
         Obligor or any other guarantor or surety.

This Guarantee shall continue to be effective or be reinstated, as the case may
be, if at any time any payment of any of the Guaranteed Obligations is rescinded
or must otherwise be


<PAGE>
                                       71


returned by any upon the insolvency, bankruptcy or reorganization of any Obligor
or otherwise, all as though such payment had not been made.

                  SECTION 8.03. WAIVERS AND ACKNOWLEDGMENTS. (a) Each of the
Guarantors hereby waives promptness, diligence, notice of acceptance and any
other notice with respect to any of the Guaranteed Obligations and this
Guarantee and any requirement that any Agent protect, secure, perfect or insure
any Lien or any property subject thereto or exhaust any right or take any action
against any Obligor or any other Person.

                  (b) Each of the Guarantors hereby waives any right to revoke
this Guarantee, and acknowledges that this Guarantee is continuing in nature and
applies to all Guaranteed Obligations, whether existing now or in the future.

                  (c) Each of the Guarantors acknowledges that it will receive
substantial direct and indirect benefits from the financing arrangements
contemplated hereunder and that the waivers set forth in this Section 8.03 are
knowingly made in contemplation of such benefits.

                  SECTION 8.04. SUBROGATION. Each of the Guarantors will not
exercise any rights that it may now or hereafter acquire against any Obligor or
any other insider guarantor that arise from the existence, payment, performance
or enforcement of the obligations of any of the Guarantors under or in respect
of this Guarantee or any Loan Document, including, without limitation, any right
of subrogation, reimbursement, exoneration, contribution or indemnification and
any right to participate in any claim or remedy of any Agent against any Obligor
or any other insider guarantor, whether or not such claim, remedy or right
arises in equity or under contract, statute or common law, including, without
limitation, the right to take or receive from any Obligor or any other insider
guarantor, directly or indirectly, in cash or other property or by set-off or in
any other manner, payment or security on account of such claim, remedy or right,
unless and until all of the obligations and all other amounts payable hereunder
shall have been paid in full in cash and the Commitments shall have expired or
terminated. If any amount shall be paid to any of the Guarantors in violation of
the preceding sentence at any time prior to the later of the payment in full in
cash of the Guaranteed Obligations and all other amounts payable hereunder and
the Maturity Date, such amount shall be held in trust for the benefit of the
Administrative Agent and shall forthwith be paid to the Administrative Agent to
be credited and applied to the Guaranteed Obligations and all other amounts
payable hereunder, whether matured or unmatured, in accordance with the terms
hereof, or such amounts payable hereunder thereafter arising. If (i) any of the
Guarantors shall make payment to the Administrative Agent of all or any part of
the Guaranteed Obligations, (ii) all of the Guaranteed Obligations and all other
amounts payable under this Guarantee shall be paid in full in cash and (iii) the
Maturity Date shall have occurred, the Administrative Agent will, at any such
Guarantor's request and expense, execute and deliver to such Guarantor
appropriate documents, without recourse and without representation or warranty,
necessary to evidence the transfer by subrogation to such Guarantor of an
interest in the Guaranteed Obligations resulting from such payment by such
Guarantor.



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                                       72

                  SECTION 8.05. CONTINUING GUARANTEE. The Guarantee under this
Article VIII is a continuing guarantee and shall (a) remain in full force and
effect until the earlier to occur of (i) the later of the payment in full in
cash of the Guaranteed Obligations and all other amounts payable hereunder and
the Termination Date and (ii) as to any Guarantor, the sale or disposition of
all of all of the Capital Stock of such Guarantor, (b) be binding upon each of
the Guarantors, their respective successors and assigns and (c) inure to the
benefit and be enforceable by each Agent and the other Lenders and their
respective successors, transferees and assigns.

                                   ARTICLE IX

                                  MISCELLANEOUS

                  SECTION 9.01. AMENDMENTS, ETC. No amendment or waiver of any
provision of the Loan Documents, nor consent to any departure by any Loan Party
therefrom, shall in any event be effective unless the same shall be in writing
and signed by the Required Lenders, and then such waiver or consent shall be
effective only in the specific instance and for the specific purpose for which
given; PROVIDED, HOWEVER, that no amendment, waiver or consent shall, unless in
writing and signed by each affected Lender, do any of the following: (a) waive
any of the conditions specified in Section 3.01 or 3.02 hereof, (b) increase the
Commitments of any Lender or subject any Lender to any additional obligations,
(c) reduce the principal of, or interest on, the Advances or any fees or other
amounts payable hereunder, (d) postpone any date fixed for any payment of
principal of, or interest on, the Advances or any fees or other amounts payable
hereunder, (e) change the percentage of the Commitments or of the aggregate
unpaid principal amount of the Advances, or the number of Lenders, that shall be
required for the Lenders or any of them to take any action hereunder, (f)
release substantially all of the collateral held or guarantees made to secure
the obligations of any Loan Party under the Loan Documents or (g) amend this
Section 9.01; and PROVIDED FURTHER that no amendment, waiver or consent shall,
unless in writing and signed by an Agent in addition to the Lenders required
above to take such action, affect the rights or duties of such Agent under the
Loan Documents.

                  SECTION 9.02. NOTICES, ETC. All notices and other
communications provided for hereunder shall be in writing (including telecopier,
telegraphic or telex communication) and mailed, telecopied, telegraphed, telexed
or delivered, if to any Loan Party to such Loan Party in case of the Parent at
its address at Militarstrasse 36, CH-8004 Zurich, Switzerland, Attention:
General Counsel; if to any Initial Lender, at its address listed on Schedule I
hereto; if to any other Lender, at its address specified in the Assignment and
Acceptance pursuant to which it became a Lender; and if to the Administrative
Agent or Security Agent , at its address at 1585 Broadway, New York, New York
10036 USA, Attention: James Morgan; or, as to any Loan Party, to it in care of
the Parent at such other address of the Parent as shall be designated by such
party in a written notice to the other parties and, as to any Lender or Agent,
at such other address as shall be designated by such party in a written notice
to the Parent and the Administrative Agent. All such notices and communications
shall, when mailed, telecopied, telegraphed or telexed, be effective when
deposited in the mails, telecopied, delivered to the telegraph company or
confirmed by telex answerback, respectively, except

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                                       73

that notices and communications to the Administrative Agent pursuant to Article
II, III or VII shall not be effective until received by the Administrative
Agent. Delivery by telecopier of an executed counterpart of any amendment or
waiver of any provision of this Agreement or of any Exhibit hereto to be
executed and delivered hereunder shall be as effective as delivery of a manually
executed counterpart thereof.

                  SECTION 9.03. NO WAIVER; REMEDIES. No failure on the part of
any Lender or any Agent to exercise, and no delay in exercising, any right
hereunder shall operate as a waiver thereof; nor shall any single or partial
exercise of any such right preclude any other or further exercise thereof or the
exercise of any other right. The remedies herein provided are cumulative and not
exclusive of any remedies provided by law.

                  SECTION 9.04. COSTS AND EXPENSES. (a) The Parent agrees to pay
on demand all reasonable out-of-pocket costs and expenses (inclusive of VAT
payable by the Administrative Agent or any Lender in respect of such costs, fees
and expenses to the extent that such VAT is not recovered by the Administrative
Agent or such Lender by way of credit or prepayment) of the Administrative Agent
or any Lender in connection with the preparation, execution, delivery,
administration, modification and amendment of the Loan Documents and the other
documents to be delivered hereunder, including, without limitation, (A) all
out-of-pocket due diligence, duplication, search, filing and recording expenses
and (B) the reasonable fees and expenses of a single firm of counsel (together
with any local counsel) with respect thereto and with respect to advising the
Administrative Agent as to its rights and responsibilities under the Loan
Documents. The Parent further agrees to pay on demand all reasonable out-of
pocket costs and expenses (inclusive of VAT payable by any Lender in respect of
such costs, fees and expenses to the extent that such VAT is not recovered by
such Lender by way of credit or prepayment) of the Lenders, if any (including,
without limitation, reasonable fees and expenses of a single firm of counsel
(together with any local counsel)), in connection with the enforcement (whether
through negotiations, legal proceedings or otherwise) of the Loan Documents, and
the other documents to be delivered hereunder, including, without limitation,
reasonable fees and expenses of a single firm of counsel (together with any
local counsel) for such Lenders in connection with the enforcement of rights
under this Section 9.04(a).

         (b) The Parent agrees to indemnify and hold harmless each Agent and
each Lender and each of their Affiliates and their officers, directors,
employees, agents and advisors (each, an "INDEMNIFIED PARTY") from and against
any and all claims, damages, losses, liabilities and expenses (including,
without limitation, reasonable fees and expenses of a single firm of counsel
(together with any local counsel)) that may be incurred by or asserted or
awarded against any Indemnified Party, in each case arising out of or in
connection with or by reason of (including, without limitation, in connection
with any investigation, litigation or proceeding or preparation of a defense in
connection therewith) the Loan Documents, any of the transactions contemplated
herein or the actual or proposed use of the proceeds of the Advances, except to
the extent such claim, damage, loss, liability or expense is found in a final,
non-appealable judgment by a court of competent jurisdiction (or by a settlement
tantamount to such a determination) to have resulted from an Indemnified Party's
gross negligence or willful misconduct. In the case of an investigation,
litigation or other proceeding to which the

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                                       74

indemnity in this Section 9.04(b) applies, such indemnity shall be effective
whether or not such investigation, litigation or proceeding is brought by any
Loan Party, its directors, shareholders or creditors or an Indemnified Party or
any other Person and whether or not the transactions contemplated hereby are
consummated. Each Loan Party also agrees not to assert any claim against any
Agent, any Lender, any of their Affiliates, or any of their respective
directors, officers, employees, attorneys and agents, on any theory of
liability, for special, indirect, consequential or punitive damages arising out
of or otherwise relating to the Loan Documents, any of the transactions
contemplated herein or the actual or proposed use of the proceeds of the
Advances.

         (c) If any payment of principal of any Advance is made by a Borrower to
or for the account of a Lender other than on the last day of the Interest Period
for such Advance, as a result of a payment pursuant to Section 2.08 or 2.10,
acceleration of the maturity of the Advances pursuant to Section 6.01 or for any
other reason, such Borrower shall, upon demand by such Lender (with a copy of
such demand to the Parent and the Administrative Agent), pay to the
Administrative Agent for the account of such Lender any amounts required to
compensate such Lender for any additional losses, costs or expenses that it may
reasonably incur as a result of such payment, including, without limitation, any
loss (including loss of anticipated profits), cost or expense incurred by reason
of the liquidation or reemployment of deposits or other funds acquired by any
Lender to fund or maintain such Advance.

         (d) Without prejudice to the survival of any other agreement of a Loan
Party hereunder, the agreements and obligations of such Loan Party contained in
Sections 2.09, 2.12 and 9.04 shall survive the payment in full of principal,
interest and all other amounts payable hereunder.

                  SECTION 9.05. RIGHT OF SET-OFF. Upon (i) the occurrence and
during the continuance of any Event of Default and (ii) the making of the
request or the granting of the consent specified by Section 6.01 hereof to
authorize the Administrative Agent to declare the Advances due and payable
pursuant to the provisions of Section 6.01 hereof, each Lender and each of its
Affiliates is hereby authorized at any time and from time to time thereafter, to
the fullest extent permitted by law, to set off and apply any and all deposits
(general or special, time or demand, provisional or final) at any time held and
other indebtedness at any time owing by such Lender or such Affiliate to or for
the credit or the account of any Obligor against any and all of the obligations
of such Obligor now or hereafter existing under the Loan Documents, whether or
not such Lender shall have made any demand under the Loan Documents and although
such obligations may be unmatured. Each Lender agrees promptly to notify the
Parent after any such set-off and application, PROVIDED that the failure to give
such notice shall not affect the validity of such set-off and application. The
rights of each Lender and its Affiliates under this Section 9.05 are in addition
to other rights and remedies (including, without limitation, other rights of
set-off) that such Lender and its Affiliates may have.

                  SECTION 9.06. BINDING EFFECT. This Agreement shall become
effective (other than Section 2.01 hereof, which shall only become effective
upon satisfaction of the conditions precedent set forth in Section 3.01 and 3.02
hereof) when it shall have been

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                                       75

executed by the Loan Parties and the Administrative Agent and when the
Administrative Agent shall have been notified by each Initial Lender that such
Initial Lender has executed it and thereafter shall be binding upon and inure to
the benefit of the Loan Parties, each Agent and each Lender and their respective
successors and assigns, except that no Loan Party shall have the right to assign
its rights hereunder or any interest herein without the prior written consent of
the Lenders.

                  SECTION 9.07. ASSIGNMENTS AND PARTICIPATIONS. (a) Each Lender
may and, so long as no Default shall have occurred and be continuing, if
demanded by the Parent (following a demand by such Lender pursuant to Section
2.09 or 2.12 hereof) upon at least five Business Days' notice to such Lender and
the Administrative Agent, will assign to one or more Persons all or a portion of
its rights and obligations under the Loan Documents (including, without
limitation, all or a portion of its Commitment and the Advances owing to it);
PROVIDED, HOWEVER, that (i) each such assignment shall be of a constant, and not
a varying, percentage of all rights and obligations under the Loan Documents,
(ii) except in the case of an assignment to a Person that, immediately prior to
such assignment, was a Lender or an assignment of all of a Lender's rights and
obligations under the Loan Documents, the amount of the Commitment of the
assigning Lender being assigned pursuant to each such assignment (determined as
of the date of the Assignment and Acceptance with respect to such assignment)
shall in no event be less than $5 million, (iii) each such assignment shall be
to an Eligible Assignee, and (iv) the parties to each such assignment shall
execute and deliver to the Administrative Agent, for its acceptance and
recording in the Register, an Assignment and Acceptance, subject to such
assignment and a processing and recordation fee of $2000; PROVIDED, FURTHER that
any assignments other than to a Lender or an Affiliate of a Lender shall be
subject to the Parent's prior written consent (which consent shall not be
unreasonably withheld), no such assignment shall increase the Obligors'
obligations under Sections 2.09 or 2.12 hereof and for each such assignment made
as a result of a demand by the Parent pursuant to this Section 9.07(a), the
Parent shall pay to the Administrative Agent the applicable processing and
recordation fee. Upon such execution, delivery, acceptance and recording, from
and after the effective date specified in each Assignment and Acceptance, (x)
the assignee thereunder shall be a party hereto and, to the extent that rights
and obligations hereunder have been assigned to it pursuant to such Assignment
and Acceptance, have the rights and obligations of a Lender hereunder and (y)
the Lender assignor thereunder shall, to the extent that rights and obligations
hereunder have been assigned by it pursuant to such Assignment and Acceptance,
relinquish its rights and be released from its obligations under the Loan
Documents (and, in the case of an Assignment and Acceptance covering all or the
remaining portion of an assigning Lender's rights and obligations under the Loan
Documents, such Lender shall cease to be a party hereto).

         (b) By executing and delivering an Assignment and Acceptance, the
Lender assignor thereunder and the assignee thereunder confirm to and agree with
each other and the other parties hereto as follows: (i) other than as provided
in such Assignment and Acceptance, such assigning Lender makes no representation
or warranty and assumes no responsibility with respect to any statements,
warranties or representations made in or in connection with the Loan Documents
or the execution, legality, validity, enforceability, genuineness, sufficiency
or value of, or the perfection or priority of any lien or security interest
created or purported to be

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                                       76

created under or in connection with, the Loan Documents or any other instrument
or document furnished pursuant hereto; (ii) such assigning Lender makes no
representation or warranty and assumes no responsibility with respect to the
financial condition of any Loan Party or the performance or observance by such
Loan Party of any of its obligations under the Loan Documents or any other
instrument or document furnished pursuant hereto; (iii) such assignee confirms
that it has received a copy of the Loan Documents, together with copies of the
financial statements referred to in Section 4.01 hereof and such other documents
and information as it has deemed appropriate to make its own credit analysis and
decision to enter into such Assignment and Acceptance; (iv) such assignee will,
independently and without reliance upon the Administrative Agent, such assigning
Lender or any other Lender 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 action under the Loan Documents; (v) such assignee confirms
that it is an Eligible Assignee; (vi) such assignee appoints and authorizes the
Administrative Agent and the Security Agent to take such action as agent on its
behalf and to exercise such powers and discretion under the Loan Documents as
are delegated to such Administrative Agent and Security Agent by the terms
hereof, together with such powers and discretion as are reasonably incidental
thereto; and (vii) such assignee agrees that it will perform in accordance with
their terms all of the obligations that by the terms of the Loan Documents are
required to be performed by it as a Lender.

         (c) The Administrative Agent shall maintain at its address referred to
in Section 9.02 hereof a copy of each Assignment and Acceptance delivered to and
accepted by it and a register for the recordation of the names and addresses of
the Lenders and the Commitment of, and principal amount of the Advances owing
to, each Lender from time to time (the "REGISTER"). The entries in the Register
shall be conclusive and binding for all purposes, absent manifest error, and
each Loan Party, the Administrative Agent, Security Agent, Lead Arrangers and
the Lenders may treat each Person whose name is recorded in the Register as a
Lender hereunder for all purposes of the Loan Documents. The Register shall be
available for inspection by any Loan Party or any Lender at any reasonable time
and from time to time upon reasonable prior notice.

         (d) Upon its receipt of an Assignment and Acceptance executed by an
assigning Lender and an assignee representing that it is an Eligible Assignee,
the Administrative Agent shall, if such Assignment and Acceptance has been
completed and is in substantially the form of Exhibit C hereto, (i) accept such
Assignment and Acceptance, (ii) record the information contained therein in the
Register and (iii) give prompt notice thereof to the Parent.

         (e) Each Lender may sell participations to one or more banks or other
entities (other than any Loan Party or any of its Affiliates) in or to all or a
portion of its rights and obligations under the Loan Documents (including,
without limitation, all or a portion of its Commitment, the Advances owing to
it); PROVIDED, HOWEVER, that (i) such Lender's rights (including without
limitation its rights under Section 2.09 and 2.12 hereof) and obligations under
the Loan Documents (including, without limitation, its Commitment to each
Borrower hereunder) shall remain unchanged, (ii) such Lender shall remain solely
responsible to the other parties hereto for the performance of such obligations,
(iii) each Loan Party, the Agents and the other Lenders shall continue to deal
solely and directly with such Lender in connection

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                                       77

with such Lender's rights and obligations under the Loan Documents and (iv) no
participant under any such participation shall have any right to approve any
amendment or waiver of any provision of the Loan Documents, or any consent to
any departure by any Loan Party therefrom, except to the extent that such
amendment, waiver or consent would reduce the principal of, or interest on, the
Advances or any fees or other amounts payable hereunder, in each case to the
extent subject to such participation, or postpone any date fixed for any payment
of principal of, or interest on, the Advances or any fees or other amounts
payable hereunder, in each case to the extent subject to such participation.

         (f) Any Lender may, in connection with any assignment or participation
or proposed assignment or participation pursuant to this Section 9.07, disclose
to the assignee or participant or proposed assignee or participant, any
information relating to any Loan Party furnished to such Lender by or on behalf
of such Loan Party; PROVIDED that, prior to any such disclosure, the assignee or
participant or proposed assignee or participant shall agree to preserve the
confidentiality of any Confidential Information relating to any Loan Party
received by it from such Lender.

         (g) Notwithstanding any other provision set forth in the Loan
Documents, any Lender may at any time create a security interest in all or any
portion of its rights under the Loan Documents (including, without limitation,
the Advances owing to it) in favor of any Federal Reserve Bank in accordance
with Regulation A of the Board of Governors of the Federal Reserve System.

         (h) For the avoidance of doubt, Morgan Stanley Dean Witter Bank Limited
is a party to this Agreement as an Affiliate of a Lender and MSSF may, at any
time, assign all or any of its rights and benefits hereunder or transfer in
accordance with this Section 9.07 all or any of its rights, benefits and
obligations hereunder to any of its Affiliates. References in this Agreement to
MSSF's Commitment shall also include the commitment of Morgan Stanley Dean
Witter Bank Limited (in such proportions as Morgan Stanley Dean Witter Bank
Limited notifies to the Administrative Agent from time to time) and MSSF is a
party to this Agreement to give effect to its Commitment.

                  SECTION 9.08. CONFIDENTIALITY. No Agent nor any Lender shall
disclose any Confidential Information to any other Person without the consent of
the Parent, other than (a) to any Agent's or such Lender's Affiliates and their
officers, directors, employees, agents and advisors and, as contemplated by
Section 9.07(f), to actual or prospective assignees and participants, and then
only on a confidential basis, (b) as required by any law, rule or regulation or
judicial process and (c) as requested or required by any state, federal or
foreign authority or examiner regulating banks or banking having jurisdiction
over such Lender.

                  SECTION 9.09. GOVERNING LAW. This Agreement shall be governed
by, and construed in accordance with, the laws of the State of New York.

                  SECTION 9.10. EXECUTION IN COUNTERPARTS. This Agreement may be
executed in any number of counterparts and by different parties hereto in
separate counterparts, each of which when so executed shall be deemed to be an
original and all of which taken together

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                                       78

shall constitute one and the same agreement. Delivery of an executed counterpart
of a signature page to this Agreement by telecopier shall be effective as
delivery of a manually executed counterpart of this Agreement.

                  SECTION 9.11. JUDGMENT. (a) If for the purposes of obtaining
judgment in any court it is necessary to convert a sum due hereunder in Dollars
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 Administrative Agent could
purchase Dollars with such other currency at Citibank, N.A.'s principal office
in London at 11:00 A.M. (London time) on the Business Day preceding that on
which final judgment is given.

                  (b) If for the purposes of obtaining judgment in any court it
is necessary to convert a sum due hereunder in a foreign currency into Dollars,
the parties 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 Administrative Agent could purchase such foreign currency
with Dollars at Citibank, N.A.'s principal office in London at 11:00 A.M.
(London time) on the Business Day preceding that on which final judgment is
given.

                  (c) The obligation of each Loan Party in respect of any sum
due from it in any currency (the "PRIMARY CURRENCY") to any Lender or any Agent
hereunder shall, notwithstanding any judgment in any other currency, be
discharged only to the extent that on the Business Day following receipt by such
Lender or Agent (as the case may be), of any sum adjudged to be so due in such
other currency, such Lender or Agent (as the case may be) may in accordance with
normal banking procedures purchase the applicable Primary Currency with such
other currency; if the amount of the applicable Primary Currency so purchased is
less than such sum due to such Lender or Agent (as the case may be) in the
applicable Primary Currency, each Loan Party agrees, as a separate obligation
and notwithstanding any such judgment, to indemnify such Lender or Agent (as the
case may be) against such loss, and if the amount of the applicable Primary
Currency so purchased exceeds such sum due to any Lender or Agent (as the case
may be) in the applicable Primary Currency, such Lender or Agent (as the case
may be) agrees to remit to the Loan Party such excess.

                  SECTION 9.12. JURISDICTION, ETC. (a) Each of the parties
hereto hereby irrevocably and unconditionally submits, for itself and its
property, to the nonexclusive jurisdiction of any New York State court or
federal court of the United States of America sitting in New York City, and any
appellate court from any thereof, in any action or proceeding arising out of or
relating to any Loan Document, or for recognition or enforcement of any
judgment, and each of the parties hereto hereby irrevocably and unconditionally
agrees that all claims in respect of any such action or proceeding may be heard
and determined in any such New York State court or, to the extent permitted by
law, in such federal court. Each of the parties hereto agrees that a final
judgment in any such action or proceeding shall be conclusive and may be
enforced in other jurisdictions by suit on the judgment or in any other manner
provided by law. Nothing in this Agreement shall affect any right that any party
may otherwise have to bring any action or proceeding relating to the Loan
Documents in the courts of any jurisdiction. Each Loan Party agrees that the
process by which any suit, action or

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                                       79

proceeding in the City of New York is begun may be served on it by being
delivered to the Person named as the process agent of such Party on Exhibit F
hereto at the address set forth therein as at the principal New York City office
of such process agent, if not the same.

         (b) Each of the parties hereto irrevocably and unconditionally waives,
to the fullest extent it may legally and effectively do so, any objection that
it may now or hereafter have to the laying of venue of any suit, action or
proceeding arising out of or relating to the Loan Documents in any New York
State or federal court. Each of the parties hereto hereby irrevocably waives, to
the fullest extent permitted by law, the defense of an inconvenient forum to the
maintenance of such action or proceeding in any such court.

                  SECTION 9.13. WAIVER OF JURY TRIAL. Each of the Loan Parties,
each Agent and the Lenders hereby irrevocably waives all right to trial by jury
in any action, proceeding or counterclaim (whether based on contract, tort or
otherwise) arising out of or relating to the Loan Documents or the actions of
any Agent or any Lender in the negotiation, administration, performance or
enforcement thereof.

<PAGE>


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

                                   CARRIER 1 INTERNATIONAL S.A.,
                                   as Parent

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 NETWORK FIBER GMBH
                                   & CO. OHG as Borrower

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 GMBH & CO. KG,
                                   as Borrower

                                   By  /s/ Edward Gross
                                     -------------------------------------------
                                     Name:  Edward Gross
                                     Title: Managing Director

                                   CARRIER 1 FRANCE S.A.R.L.,
                                   as Borrower

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 UK LIMITED, as Borrower

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 INTERNATIONAL GMBH,
                                   as Borrower

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

<PAGE>


                                   CARRIER 1 FIBER NETWORK GMBH & CO.
                                   OHG, as Guarantor

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 GMBH & CO. KG,
                                   as Guarantor

                                   By /s/ Edward Gross
                                     -------------------------------------------
                                     Name:  Edward Gross
                                     Title: Managing Director

                                   CARRIER 1 HOLDING GMBH,
                                   as Guarantor

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 BETEILIGUNGS GMBH,
                                   as Guarantor

                                   By /s/ Edward Gross
                                     -------------------------------------------
                                     Name:  Edward Gross
                                     Title: Managing Director

                                   CARRIER 1 FIBER NETWORK
                                   BETEILIGUNGS GMBH, as Guarantor

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:


<PAGE>


                                   CARRIER 1 FRANCE S.A.R.L., as Guarantor

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 FRANCE HOLDING, as Guarantor

                                   By /s/ I. Russier
                                     -------------------------------------------
                                     Name:  I. Russier
                                     Title: Gerante

                                   CARRIER 1 UK LIMITED, as Guarantor

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   CARRIER 1 INTERNATIONAL GMBH,
                                   as Guarantor

                                   By /s/ Stig Johansson
                                     -------------------------------------------
                                     Name:  Stig Johansson
                                     Title:

                                   MORGAN STANLEY SENIOR
                                   FUNDING, INC., as Administrative Agent

                                   By /s/ Philippe Lagarde
                                     -------------------------------------------
                                     Name:  Philippe Lagarde
                                     Title: Vice President

                                   MORGAN STANLEY SENIOR
                                   FUNDING, INC., as Security Agent

                                   By /s/ Philippe Lagarde
                                     -------------------------------------------
                                     Name:  Philippe Lagarde
                                     Title: Vice President


<PAGE>


                                   MORGAN STANLEY SENIOR
                                   FUNDING, INC., as Lead Arranger

                                   By /s/ Philippe Lagarde
                                     -------------------------------------------
                                     Name:  Philippe Lagarde
                                     Title: Vice President

                                   CITIBANK, N.A,  as Lead Arranger

                                   By /s/ Peder Oien
                                     -------------------------------------------
                                     Name:  Peder Oien
                                     Title: Vice President

                                   MORGAN STANLEY SENIOR
                                   FUNDING, INC., as Initial Lender

                                   By /s/ Philippe Lagarde
                                     -------------------------------------------
                                     Name:  Philippe Lagarde
                                     Title: Vice President

                                   CITIBANK, N.A., as Initial Lender

                                   By /s/ Peder Oien
                                     -------------------------------------------
                                     Name:  Peder Oien
                                     Title: Vice President

                                   MORGAN STANLEY DEAN WITTER BANK
                                   LIMITED, as Lender

                                   By /s/ Kevin M. Adeeon
                                     -------------------------------------------
                                     Name:  Kevin M. Adeeon
                                     Title: Executive Director

<PAGE>

                                   SCHEDULE 1

                     LIST OF INITIAL LENDERS AND COMMITMENTS

<TABLE>
<CAPTION>

INITIAL LENDER              ADDRESS                       COMMITMENT

<S>                         <C>                           <C>
Morgan Stanley Senior       1585 Broadway                 $100 million
Funding, Inc.               New York, New York 10036



Citibank, N.A.              336 Strand                    $100 million
                            London WC2R 1HB


                                                          $200 million Total of
                                                          Commitments

</TABLE>

<PAGE>

<TABLE>
<CAPTION>
                               SCHEDULE 4.01(a) - CORPORATE STRUCTURE OF THE CARRIER 1 GROUP

                                   ----------------------------------------------------
                                               Carrier 1 International S.A.
                                                 (Luxembourg)(1,2,3,6,7)
                                   ----------------------------------------------------
<S>                        <C>                        <C>                      <C>
------------------------------------------------------------------------------------------------------------------------------------
     Carrier 1 B.V.          Carrier 1 UK Limited     Carrier 1 International
       (Amsterdam)                 (1,3,6,7)                    GmbH                         Carrier 1 Holding GmbH (4)
                                   (London)               (Zurich)(1,2,5)
------------------------------------------------------------------------------------------------------------------------------------
        Carrier 1          Carrier 1 Belgium SPRL (6)    Carrier 1 Networks    Carrier 1 Beteiligungs GmbH   Carrier 1 Fiber Network
 Telecommunikation GmbH           (Brussels)                    GmbH                   (Frankfurt)              Beteiligungs GmbH
        (Vienna)                                            (Zurich)(5)                                            (Frankfurt)
------------------------------------------------------------------------------------------------------------------------------------
    Carrier 1 Iberia             Carrier 1 SaP        Carrier 1 International     Carrier 1 GmbH & Co KG     Carrier 1 Fiber Network
        (Madrid)                 (Copenhagen)             Management S.A.                                        GmbH & Co. oHG
      (in progress)              (in progress)              (Luxembourg)                                           (Frankfurt)
------------------------------------------------------------------------------------------------------------------------------------
   Carrier Nordics Ab      Carrier 1 Italia Srl (7)        Carrier 1 Inc.
       (Stockholm)                 (Milano)                  (Delaware)
------------------------------------------------------------------------------------------------------------------------------------
  Carrier 1 Nordics AB                                Carrier 1 International
       (Norwegian                                         Management S.A.
     Branch Office)                                    (Swiss Branch Office)
-------------------------
    Carrier 1 France
      Holding (2,3)
         (Paris)
-------------------------
    Carrier 1 France
       S.A.R.L.(3)
         (Paris)
-------------------------

1.  Carrier 1 International GmbH holdings is held by Carrier 1 International S.A. (98%) and Carrier 1 UK Limited (2%).

2.  Carrier 1 France Holding is held by Carrier 1 International S.A. (99.99%) and Carrier 1 International GmbH (0.01%).

3.  Carrier 1 France S.A.R.L. is held by Carrier 1 France Holding (99.99%) and Carrier 1 UK Limited (0.01%).

4.  The economic value of Carrier 1 GmbH & Co KG and Carrier 1 Fiber GmbH & Co. oHG is solely held by Carrier 1 Holding GmbH.

5.  Carrier 1 Networks GmbH is held by Carrier 1 International GmbH (95%) and by Mr. Philip Walter (5%).

6.  Carrier 1 Belgium SPRL is held by Carrier 1 International S.A. (99.933%) and Carrier 1 UK Limited (0.66%).

7.  Carrier 1 Italia Srl is held by Carrier 1 International S.A. (99%) and Carrier 1 UK Limited (1%).
</TABLE>

<PAGE>

                                   EXHIBIT A-1

                                LIST OF BORROWERS

Carrier 1 Fiber Network GmbH & Co. oHG
Carrier 1 GmbH & Co. KG
Carrier 1 France S.A.R.L.
Carrier 1 UK Limited
Carrier 1 International GmbH
<PAGE>

                                   EXHIBIT A-2

                               LIST OF GUARANTORS

Carrier 1 Fiber Network GmbH & Co. oHG
Carrier 1 GmbH & Co.  KG
Carrier 1 Holding GmbH
Carrier 1 Beteiligungs GmbH
Carrier 1 Fiber Network Beteiligungs GmbH
Carrier 1 France S.A.R.L.
Carrier 1 France Holding
Carrier 1 UK Limited
Carrier1 International GmbH

<PAGE>

                                    EXHIBIT B

                           FORM OF NOTICE OF BORROWING

Morgan Stanley Senior Funding, Inc., as Administrative Agent
  for the Lenders parties
  to the Credit Agreement
  referred to below
1585 Broadway
New York, NY 10036                                        [Date]

                  Attention:  ____________________

Ladies and Gentlemen:

                  The undersigned, [Name of Borrower], refers to the Credit
Agreement, dated as of December 21, 1999 (as amended or modified from time to
time, the "CREDIT AGREEMENT", the terms defined therein being used herein as
therein defined), among Carrier1 International, S.A. (the "PARENT"), certain
Subsidiaries of the Parent (including the undersigned), certain Lenders
parties thereto and Morgan Stanley Senior Funding, Inc., as Administrative
Agent for said Lenders, and hereby gives you notice, irrevocably, pursuant to
Section 2.02 of the Credit Agreement that the undersigned hereby requests a
Borrowing under the Credit Agreement, and in that connection sets forth below
the information relating to such Borrowing (the "PROPOSED BORROWING") as
required by Section 2.02(a) of the Credit Agreement:

                  (i) The Business Day of the Proposed Borrowing is
         _______________, 2000.

                  (ii) The Proposed Borrowing shall be made in [Dollars]
         [Euros].

                  (iii) The aggregate amount of the Proposed Borrowing is [$]
         [Euro] __________________

                  (iv) The initial Interest Period for each Advance made as part
         of the Proposed Borrowing is __________ month[s].

                  The Parent hereby certifies that the following statements are
true on the date hereof, and will be true on the date of the Proposed Borrowing:

                  (A) the representations and warranties contained in Section
         4.01 of the Credit Agreement are correct, before and after giving
         effect to the Proposed Borrowing and to the application of the proceeds
         therefrom, as though made on and as of such date; and

                  (B) no event has occurred and is continuing, or would result
         from such Proposed Borrowing or from the application of the proceeds
         therefrom, that constitutes a Default.

<PAGE>

                                   Very truly yours,

                                   [NAME OF BORROWER]

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

 CARRIER1 INTERNATIONAL S.A.

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

<PAGE>

                                    EXHIBIT C

                        FORM OF ASSIGNMENT AND ACCEPTANCE

                  Reference is made to the Credit Agreement dated as of
December 21, 1999 (as amended or modified from time to time, the "CREDIT
AGREEMENT"; the terms defined therein being used herein as therein defined)
among Carrier1 International S.A., as Parent, the Borrowers and Guarantors
named therein, the Lead Arrangers, the Security Agent, the Lenders (as
defined in the Credit Agreement) and Morgan Stanley Senior Funding, Inc., as
administrative agent for the Lenders (the "ADMINISTRATIVE AGENT").

                  The "Assignor" and the "Assignee" referred to on Schedule I
hereto agree as follows:

                  1. The Assignor hereby sells and assigns to the Assignee, and
         the Assignee hereby purchases and assumes from the Assignor, an
         interest in and to the Assignor's rights and obligations under the Loan
         Documents as of the date hereof equal to the percentage interest
         specified on Schedule 1 hereto of all outstanding rights and
         obligations under such Loan Documents. After giving effect to such sale
         and assignment, the Assignee's Commitment and the amount of the
         Advances owing to the Assignee will be as set forth on Schedule 1
         hereto.

                  2. The Assignor (i) represents and warrants that it is the
         legal and beneficial owner of the interest being assigned by it
         hereunder and that such interest is free and clear of any adverse
         claim; (ii) makes no representation or warranty and assumes no
         responsibility with respect to any statements, warranties or
         representations made in or in connection with the Loan Documents or the
         execution, legality, validity, enforceability, genuineness, sufficiency
         or value of, or the perfection or priority of any lien or security
         interest created or purported to be created under or in connection
         with, such Loan Documents or any other instrument or document furnished
         pursuant thereto; (iii) makes no representation or warranty and assumes
         no responsibility with respect to the financial condition of the Loan
         Parties or the performance or observance by any Loan Party of any of
         its obligations under the Loan Documents or any other instrument or
         document furnished pursuant thereto.

                  3. The Assignee (i) confirms that it has received a copy of
         the Loan Documents, together with copies of the financial statements
         referred to in Section 4.01 of the Credit Agreement and such other
         documents and information as it has deemed appropriate to make its own
         credit analysis and decision to enter into this Assignment and
         Acceptance; (ii) agrees that it will, independently and without
         reliance upon the Administrative Agent, the Assignor or any other
         Lender 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 action under the Loan Documents; (iii) confirms
         that it is an Eligible Assignee; (iv) appoints and authorizes the
         Administrative Agent to take such action as agent on its behalf and to
         exercise such powers and discretion under the Loan Documents as are
         delegated to the Administrative Agent by the terms thereof, together
         with such powers and discretion

<PAGE>

         as are reasonably incidental thereto; (v) agrees that it will perform
         in accordance with their terms all of the obligations that by the terms
         of the Loan Documents are required to be performed by it as a Lender.

                  4. Following the execution of this Assignment and Acceptance,
         it will be delivered to the Parent for its acceptance and, if so
         accepted, to the Administrative Agent for acceptance and recording by
         the Administrative Agent. The effective date for this Assignment and
         Acceptance (the "EFFECTIVE DATE") shall be the date of acceptance
         hereof by the Administrative Agent, unless otherwise specified on
         Schedule 1 hereto.

                  5. Upon such acceptance and recording by the Administrative
         Agent, as of the Effective Date, (i) the Assignee shall be a party to
         the Loan Documents and, to the extent provided in this Assignment and
         Acceptance, have the rights and obligations of a Lender thereunder and
         (ii) the Assignor shall, to the extent provided in this Assignment and
         Acceptance, relinquish its rights and be released from its obligations
         under the Loan Documents.

                  6. Upon such acceptance and recording by the Administrative
         Agent, from and after the Effective Date, the Administrative Agent
         shall make all payments under the Loan Documents in respect of the
         interest assigned hereby (including, without limitation, all payments
         of principal, interest and facility fees with respect thereto) to the
         Assignee. The Assignor and Assignee shall make all appropriate
         adjustments in payments under the Loan Documents for periods prior to
         the Effective Date directly between themselves.

                  7. This Assignment and Acceptance shall be governed by, and
         construed in accordance with, the laws of the State of New York.

                  8. This Assignment and Acceptance may be executed in any
         number of counterparts and by different 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. Delivery of an executed counterpart of Schedule 1 to
         this Assignment and Acceptance by telecopier shall be effective as
         delivery of a manually executed counterpart of this Assignment and
         Acceptance.

                  IN WITNESS WHEREOF, the Assignor and the Assignee have caused
Schedule 1 to this Assignment and Acceptance to be executed by their officers
thereunto duly authorized as of the date specified thereon.

<PAGE>

                                   Schedule 1

                                       to

                            Assignment and Acceptance

         Percentage interest assigned:                                    _____%

         Assignee's Commitment:
         $_______________

         Aggregate outstanding principal amount of Advances assigned
         $_______________

         Principal amount of Advances payable to Assignee:
         $_______________

         Principal amount of Advances payable to Assignor:
         $_______________

         Effective Date:            _______________, 2000

                                   [NAME OF ASSIGNOR], as Assignor

                                   By
                                     -------------------------------------------
                                     Name:
                                     Title:
                                   Dated:  _______________, 2000

                                   [NAME OF ASSIGNEE], as Assignee

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

                                   [Address]

Accepted and Approved this
__________ day of _______________, 2000

MORGAN STANLEY SENIOR FUNDING, INC.,
as Administrative Agent

<PAGE>

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

Approved this __________ day
of _______________, 2000

Carrier1 International S.A. as Parent

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

<PAGE>

                                    EXHIBIT D

               FORM OF OPINION OF THE LOAN PARTIES' LOCAL COUNSEL

[For German, Swiss, French and U.K. counsel]

                                                                       [Date]

To the Lenders party to the Credit Agreement
referred to below and to Morgan Stanley
Senior Funding, Inc. as Administrative Agent
and as Security Agent for such Lenders

Ladies and Gentlemen:

                  This opinion is furnished to you pursuant to Section
3.01(i)(iv) and Section 3.02[ ] of the Credit Agreement dated December 21, 1999,
(the "CREDIT AGREEMENT"), among Carrier1 International S.A., the Borrowers and
Guarantors named therein, the Initial Lenders and Lenders named therein, Morgan
Stanley Senior Funding, Inc. and Citibank, N.A. as lead arrangers (the "LEAD
ARRANGERS") and Morgan Stanley Senior Funding, Inc., as administrative agent
(the "ADMINISTRATIVE AGENT") and security agent (the "SECURITY AGENT"). Terms
defined in the Credit Agreement are used herein as therein defined.

                  We have acted as [name of jurisdiction] counsel to [name of
company] (the "COMPANY") in connection with the preparation, execution and
delivery of, and the initial Advances made under, the Credit Agreement and in
connection with the preparation, execution and delivery of the [name of
jurisdiction] Pledge Agreement (the "PLEDGE AGREEMENT").

                  In that connection, we have examined counterparts of the
Credit Agreement and the Pledge Agreement, executed by each of the parties
thereto, and the other documents furnished by the Company pursuant to Article
III of the Credit Agreement, including:

                  (a) the certificate of incorporation and bylaws of the Company
         as amended through the date hereof;

                  (b) a certified copy of the resolutions of the Company
         approving the Loan Documents to which it is a party and of all
         documents evidencing other necessary corporate action and governmental
         approvals, if any, with respect to the Loan Documents;

                  (c) an officer's certificate of the Company certifying the
         names and true signatures of the officers of the Company authorized to
         sign the Loan Documents to which it is a party.

                  In addition, we have examined the originals, or copies
certified to our satisfaction, of such other corporate records of the Company,
certificates of public officials and of officers of the Company and agreements,
instruments and other documents as we have

<PAGE>

deemed necessary as a basis for the opinions expressed below. As to questions of
fact material to such opinions, we have, when relevant facts were not
independently established by us, relied upon certificates of the Company or of
its officers or of public officials.

                  In our examination of the documents referred to above, we have
assumed (i) the due execution and delivery, pursuant to due authorization, of
each of the documents referred to above by all parties thereto other than the
Company, (ii) the authenticity of all such documents submitted to us as
originals and (iii) the conformity to originals of all such documents submitted
to us as copies.

                  We are qualified to practice law in [name of jurisdiction] and
we do not purport to be experts on any laws other than the laws of [name of
jurisdiction].

                  Based upon the foregoing and upon such investigation as we
have deemed necessary, we are of the following opinion:

                  1. The Company is a corporation duly organized, validly
         existing and in good standing under the laws of the jurisdiction of its
         incorporation.

                  2. The execution, delivery and performance by the Company of
         each of the Loan Documents to which it is a party, and the consummation
         of the transactions contemplated by the Loan Documents are within the
         Company's corporate powers, have been duly authorized by all necessary
         corporate action, and do not (a) contravene the Company's charter or
         bylaws, (b) violate any law, rule, regulation or any order, writ,
         judgment, injunction, decree, determination or award, (c) conflict with
         or result in the breach of, or constitute a default under, any
         agreement or instrument to which the Company is a party or (d) except
         for the Liens created by the Pledge Agreement result in or require the
         creation or imposition of any Lien upon or with respect to any of the
         properties of the Company or any of its Subsidiaries.

                  3. No authorization or approval or other action by, and no
         notice to or filing with, any governmental authority or regulatory
         body, is required for (a) the due execution, delivery, recordation,
         filing or performance by the Company of the Loan Documents to which it
         is a party or for the consummation of the transactions contemplated by
         the Loan Documents, (b) the grant by the Company of the Liens granted
         by it pursuant to the Pledge Agreement, (c) the perfection or
         maintenance of the Liens created by the Pledge Agreement, or (d) the
         exercise by the Security Agent or any of the Lenders of its rights
         under the Loan Documents or the remedies in respect of the Collateral
         pursuant to the Pledge Agreement.

                  4. Each of the Credit Agreement and the Pledge Agreement has
         been duly executed and delivered by the Company. The Pledge Agreement
         is the legal, valid and binding obligation of the Company, enforceable
         against it in accordance with its terms.

                  5. The Pledge Agreement creates a valid and perfected security
         interest in the Collateral, securing payment of the secured obligations
         referred to in the Pledge

<PAGE>

         Agreement. All of the Pledged Shares have been validly issued and are
         fully paid and non-assessable.

                  6. All taxes and governmental fees and charges, the payment of
         which is required in connection with the execution, delivery and
         recording of the Credit Agreement or the Pledge Agreement have been
         paid.

                  7. The governing law clause, subjecting the Credit Agreement
         to New York law, is valid under [name of jurisdiction] law.

                  8. Under [name of jurisdiction] law, New York law will be
         applied to an agreement, such as the Credit Agreement, which under
         [name of jurisdiction] law has been validly subjected to New York law,
         unless any terms of such agreement or any provisions of New York law
         applicable to such agreement violate the public policy of [name of
         jurisdiction].

                  9. None of the terms of the Credit Agreement violates the
         public policy of [name of jurisdiction].

                  10. Assuming that the Credit Agreement is legal, valid and
         binding and enforceable under New York law, the Credit Agreement is
         enforceable against the Company in accordance with its terms, the rules
         of civil procedure of [name of jurisdiction] and, subject to the
         opinions in paragraphs 7-9, the applicable provisions of the chosen law
         of New York.

                  11. Any final and conclusive judgment for a definite sum of
         the Supreme Court of the State of New York, New York County, or of the
         United States District Court for the Southern District of New York
         rendered in a suit, action or proceeding against the Company arising
         out of the Credit Agreement should be enforceable against the Company
         by courts of [name of jurisdiction] provided that the requirements of
         [enumerate appropriate sections of applicable procedural law] are met.

                  12. The submission by the Company, under the Credit Agreement,
         to the jurisdiction of the courts of the State of New York and the
         United States sitting in New York County is valid and effective.

                  13. The obligations of the Company under the Credit Agreement
         rank at least pari passu in priority of payment with all other
         obligations of the Company which are not secured and which have not
         been accorded by law preferential rights, subject to the effect of
         applicable bankruptcy, insolvency, reorganization, moratorium,
         liquidation or similar laws relating to, or affecting generally the
         enforcement of creditors' rights and remedies against the Company.

                                   Very truly yours,

<PAGE>

[For Luxembourg counsel]

                                                            [Date]

To the Lenders party to the Credit Agreement
referred to below and to Morgan Stanley
Senior Funding, Inc. as Administrative Agent
and as Security Agent for such Lenders

Ladies and Gentlemen:

                  This opinion is furnished to you pursuant to Section
3.01(i)(iv) of the Credit Agreement dated December 21, 1999, (the "CREDIT
AGREEMENT"), among Carrier1 International S.A., the Borrowers and Guarantors
named therein, the Initial Lenders and Lenders named therein, Morgan Stanley
Senior Funding, Inc. and Citbank, N.A., as lead arrangers (the "LEAD
ARRANGERS") and Morgan Stanley Senior Funding, Inc., as administrative agent
(the "ADMINISTRATIVE AGENT") and security agent (the "SECURITY AGENT"). Terms
defined in the Credit Agreement are used herein as therein defined.

                  We have acted as Luxembourg counsel to Carrier1
International S.A. (the "COMPANY") in connection with the preparation,
execution and delivery of, and the initial Advances made under, the Credit
Agreement and in connection with the preparation, execution and delivery of
each other Loan Document to which it is a party.

                  In that connection, we have examined counterparts of each of
the Loan Documents executed by each of the parties thereto, and the other
documents furnished by the Company pursuant to Article III of the Credit
Agreement, including:

                  (a) the certificate of incorporation and bylaws of the Company
         as amended through the date hereof;

                  (b) a certified copy of the resolutions of the Company
         approving the Loan Documents to which it is a party and making the
         determinations required by clause (vi) of the second paragraph of
         Section 4.05 of the Indentures, and of all documents evidencing other
         necessary corporate action and governmental approvals, if any, with
         respect to the Loan Documents;

                  (c) an officer's certificate of the Company certifying the
         names and true signatures of the officers of the Company authorized to
         sign the Loan Documents to which it is a party.

                  In addition, we have examined the originals, or copies
certified to our satisfaction, of such other corporate records of the Company,
certificates of public officials

<PAGE>

and of officers of the Company and agreements, instruments and other documents
as we have deemed necessary as a basis for the opinions expressed below. As to
questions of fact material to such opinions, we have, when relevant facts were
not independently established by us, relied upon certificates of the Company or
of its officers or of public officials.

                  In our examination of the documents referred to above, we have
assumed (i) the due execution and delivery, pursuant to due authorization, of
each of the documents referred to above by all parties thereto other than the
Company, (ii) the authenticity of all such documents submitted to us as
originals and (iii) the conformity to originals of all such documents submitted
to us as copies.

                  We are qualified to practice law in Luxembourg and we do not
purport to be experts on any laws other than the laws of Luxembourg.

                  Based upon the foregoing and upon such investigation as we
have deemed necessary, we are of the following opinion:

                  1. The Company is a corporation duly organized, validly
         existing and in good standing under the laws of the jurisdiction of its
         incorporation.

                  2. The execution, delivery and performance by the Company of
         each of the Loan Documents to which it is a party, and the consummation
         of the transactions contemplated by the Loan Documents are within the
         Company's corporate powers, have been duly authorized by all necessary
         corporate action, and do not (a) contravene the Company's charter or
         bylaws, (b) violate any law, rule, regulation or any order, writ,
         judgment, injunction, decree, determination or award, (c) conflict with
         or result in the breach of, or constitute a default under, any
         agreement or instrument to which the Company is a party or (d) except
         for the Liens created by the Loan Documents result in or require the
         creation or imposition of any Lien upon or with respect to any of the
         properties of the Company or any of its Subsidiaries.

                  3. No authorization or approval or other action by, and no
         notice to or filing with, any governmental authority or regulatory
         body, is required for (a) the due execution, delivery, recordation,
         filing or performance by the Company of the Loan Documents to which it
         is a party or for the consummation of the transactions contemplated by
         the Loan Documents, (b) the grant by the Company or any of its
         Subsidiaries of the Liens granted pursuant to the Loan Documents, (c)
         the perfection or maintenance of the Liens created by the Loan
         Documents, or (d) the exercise by the Security Agent or any of the
         Lenders of its rights under the Loan Documents or the remedies in
         respect of the Collateral pursuant to the Loan Documents.

                  4. Each of the Loan Documents to which the Company is a party
         have been duly executed and delivered by the Company.

<PAGE>

                  5. All taxes and governmental fees and charges, the payment of
         which is required in connection with the execution, delivery and
         recording of the Loan Documents have been paid.

                  6. The governing law clause, subjecting the Credit Agreement
         to New York law, is valid under Luxembourg law.

                  7. Under Luxembourg law, New York law will be applied to an
         agreement, such as the Credit Agreement, which under Luxembourg law has
         been validly subjected to New York law, unless any terms of such
         agreement or any provisions of New York law applicable to such
         agreement violate the public policy of Luxembourg.

                  8. None of the terms of the Credit Agreement violates the
         public policy of Luxembourg.

                  9. Assuming that the Credit Agreement is legal, valid and
         binding and enforceable under New York law, the Credit Agreement is
         enforceable against the Company in accordance with its terms, the rules
         of civil procedure of Luxembourg and, subject to the opinions in
         paragraphs 7-9, the applicable provisions of the chosen law of New
         York.

                  10. Any final and conclusive judgment for a definite sum of
         the Supreme Court of the State of New York, New York County, or of the
         United States District Court for the Southern District of New York
         rendered in a suit, action or proceeding against the Company arising
         out of the Credit Agreement should be enforceable against the Company
         by courts of Luxembourg provided that the requirements of [enumerate
         appropriate sections of applicable procedural law] are met.

                  11. The submission by the Company, under the Credit Agreement,
         to the jurisdiction of the courts of the State of New York and the
         United States sitting in New York County is valid and effective.

                  12. The obligations of the Company under the Credit Agreement
         rank at least pari passu in priority of payment with all other
         obligations of the Company which are not secured and which have not
         been accorded by law preferential rights, subject to the effect of
         applicable bankruptcy, insolvency, reorganization, moratorium,
         liquidation or similar laws relating to, or affecting generally the
         enforcement of creditors' rights and remedies against the Company.

                                   Very truly yours,

<PAGE>

                                    EXHIBIT E

                           FORM OF ACCESSION AGREEMENT

Morgan Stanley Senior Funding, Inc., as Administrative Agent

                                                           [Date]

         Attention:  ____________________

Ladies and Gentlemen:

                  Reference is made to the Credit Agreement, dated as of
December 21, 1999 (as amended or modified from time to time, the "CREDIT
AGREEMENT", the terms defined therein being used herein as therein defined),
among Carrier1 International S.A. and the Borrowers and Guarantors named
therein, the Lenders named therein, the Lead Arrangers named therein, the
Security Agent named therein and Morgan Stanley Senior Funding, Inc., as
administrative agent (the "Administrative Agent").

                  The Acceding Borrower and Guarantor hereby agrees to become,
as of the date hereof, an Obligor under the Credit Agreement as if it were an
original party thereto and agrees that each reference in the Credit Agreement to
Borrower, Guarantor and Obligor shall also mean and be a reference to the
undersigned. By its acknowledgment and agreement below, the Administrative Agent
agrees that the undersigned shall become a party to the Credit Agreement from
the date hereof.

                  The Acceding Borrower and Guarantor hereby further:

                  (A) confirms receipt of a copy of the Credit Agreement,
                  together with such other documents and information as it has
                  required in connection herewith and therewith;

                  (B) undertakes to perform its obligations as Borrower or
                  Guarantor, as the case may be, under the Credit Agreement;

                  (C) agrees to be bound as an Obligor by all of the terms and
                  provisions of the Credit Agreement; and

                  (D) delivers to the Administrative Agent (i) certified copies
                  of its organizational documents, (ii) a certified copy of its
                  board resolutions approving the execution, delivery and
                  performance by the undersigned of the Accession Agreement in
                  the form hereof and authorizing a named person or persons to
                  sign the Accession Agreement, (iii) a certified copy of
                  authorized signatories, (iv) an officer's certificate
                  confirming that each of the representations and warranties in
                  the Loan Documents is true and correct as of

<PAGE>

                  the date hereof, (v) an opinion of counsel to substantially
                  the effect of Exhibit D of the Credit Agreement, (vi) a
                  solvency certificate from its chief financial officer on
                  behalf of it in form and substance satisfactory to the Lenders
                  and (vii) evidence that _______________ has agreed to act as
                  the undersigned's process agent for service of process in New
                  York.

                  The Acceding Borrower and Guarantor hereby agrees, jointly and
severally, to indemnify the Lender, its officers, directors, employees and
agents in the manner set forth in Section 9.04 of the Credit Agreement.

                  Carrier1 International, S.A. hereby confirms that each
representation and warranty set forth in Section 4.01 of the Credit Agreement
is true and correct as of the date hereof.

                  This Accession Agreement shall be governed by, and construed
in accordance with, the laws of the State of New York.

                                   Very truly yours,

                                   [NAME OF ACCEDING BORROWER AND
                                   GUARANTOR]

                                   By______________________________
                                     Name:
                                     Title:

                                   CARRIER1 INTERNATIONAL, S.A.

                                   By______________________________
                                     Name:
                                     Title:

Accepted and Approved this
____________ day of __________, 2000

MORGAN STANLEY SENIOR FUNDING INC.,
as Administrative Agent

By________________________________
  Name:
  Title:

<PAGE>

                                    EXHIBIT F

                            SERVICE OF PROCESS AGENT

CT Corporation System
111 8th Avenue, 13th Floor
New York, NY 10011