<PAGE>   1

                                                                   EXHIBIT 10.23
================================================================================


                              VERIO INC., as Issuer


                                       and


                  FIRST TRUST NATIONAL ASSOCIATION, as Trustee


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


                                    INDENTURE

                           Dated as of March 25, 1998


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



                                  $175,000,000


                     10-3/8% Senior Notes Due 2005, Series A

                     10-3/8% Senior Notes Due 2005, Series B




================================================================================



<PAGE>   2


Reconciliation and tie between Trust Indenture Act of 1939, as amended, and
Indenture, dated as of March 25, 1998

<TABLE>
<CAPTION>
  Trust Indenture                                                               Indenture
   Act Section                                                                   Section
  ---------------                                                               ---------
<S>                                                                             <C>
Section 310 (a)(1)...........................................................   6.05, 6.09          
            (a)(2)...........................................................   6.05, 6.09          
            (a)(3)...........................................................   6.05                
            (a)(4)...........................................................   6.05                
            (b)..............................................................   6.05, 6.08, 6.10    
Section 311 (a)..............................................................   6.07                
            (b)..............................................................   6.07                
            (c)..............................................................   Not Applicable      
Section 312 (a)..............................................................   3.05, 7.01          
            (b)..............................................................   7.02                
            (c)..............................................................   7.02                
Section 313 (a)..............................................................   7.03                
            (b)..............................................................   7.03                
            (c)..............................................................   7.03                
            (d)..............................................................   7.03                
Section 314 (a)..............................................................   7.04, 10.09         
            (b)..............................................................   Not Applicable      
            (c)(1)...........................................................   1.04, 4.04, 12.01(c)
            (c)(2)...........................................................   1.04, 4.04, 12.01(c)
            (c)(3)...........................................................                       
            (d)..............................................................   Not Applicable      
            (e)..............................................................   1.04                
Section 315 (a)..............................................................   6.01(a)             
            (b)..............................................................   6.02                
            (c)..............................................................   6.01(b)             
            (d)..............................................................   6.01(c)             
            (e)..............................................................   5.14                
Section 316 (a) (last sentence) .............................................   3.14                
            (a)(1)(A)........................................................   5.12                
            (a)(1)(B)........................................................   5.13                
            (a)(2)...........................................................   Not Applicable      
            (b)..............................................................   5.08                
Section 317 (a)(1)...........................................................   5.03                
            (a)(2)...........................................................   5.04                
            (b)..............................................................   10.03               
Section 318 (a)..............................................................   1.08                
</TABLE>


<PAGE>   3




                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
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PARTIES.....................................................................................1
RECITALS....................................................................................1

                                   ARTICLE ONE
             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

Section 1.01.  Definitions..................................................................1
Section 1.02.  Other Definitions...........................................................30
Section 1.03.  Rules of Construction.......................................................31
Section 1.04.  Form of Documents Delivered to Trustee......................................31
Section 1.05.  Acts of Holders.............................................................32
Section 1.06.  Notices, etc., to the Trustee and the Company...............................33
Section 1.07.  Notice to Holders; Waiver...................................................33
Section 1.08.  Conflict with Trust Indenture Act...........................................34
Section 1.09.  Effect of Headings and Table of Contents....................................34
Section 1.10.  Successors and Assigns......................................................35
Section 1.11.  Separability Clause.........................................................35
Section 1.12.  Benefits of Indenture.......................................................35
Section 1.13.  GOVERNING LAW...............................................................35
Section 1.14.  No Recourse Against Others..................................................35
Section 1.15.  Independence of Covenants...................................................35
Section 1.16.  Exhibits....................................................................36
Section 1.17.  Counterparts................................................................36
Section 1.18.  Duplicate Originals.........................................................36

                                   ARTICLE TWO
                                   NOTE FORMS

Section 2.01.  Form and Dating.............................................................36

                                  ARTICLE THREE
                                    THE NOTES

Section 3.01.  Title and Terms.............................................................37
</TABLE>



                                      -i-
<PAGE>   4

<TABLE>
<CAPTION>
                                                                                          Page
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<S>                                                                                        <C>
Section 3.02.  Registrar and Paying Agent..................................................37
Section 3.03.  Execution and Authentication................................................38
Section 3.04.  Temporary Notes.............................................................40
Section 3.05.  Transfer and Exchange.......................................................41
Section 3.06.  Mutilated, Destroyed, Lost and Stolen Notes.................................42
Section 3.07.  Payment of Interest; Interest Rights Preserved..............................43
Section 3.08.  Persons Deemed Owners.......................................................44
Section 3.09.  Cancellation................................................................44
Section 3.10.  Computation of Interest.....................................................45
Section 3.11.  Legal Holidays..............................................................45
Section 3.12.  CUSIP and CINS Numbers......................................................45
Section 3.13.  Paying Agent To Hold Money in Trust.........................................46
Section 3.14.  Treasury Notes..............................................................46
Section 3.15.  Deposits of Monies..........................................................46
Section 3.16.  Book-Entry Provisions for Global Notes......................................47
Section 3.17.  Special Transfer Provisions.................................................48

                                  ARTICLE FOUR
                        DEFEASANCE OR COVENANT DEFEASANCE

Section 4.01.  Company's Option To Effect Defeasance or Covenant Defeasance................52
Section 4.02.  Defeasance and Discharge....................................................53
Section 4.03.  Covenant Defeasance.........................................................53
Section 4.04.  Conditions to Defeasance or Covenant Defeasance.............................54
Section 4.05.  Deposited Money and U.S. Government Obligations To Be Held in
                   Trust; Other Miscellaneous Provisions...................................56
Section 4.06.  Reinstatement...............................................................57

                                  ARTICLE FIVE
                                    REMEDIES

Section 5.01.  Events of Default...........................................................58
Section 5.02.  Acceleration of Maturity; Rescission and Annulment..........................60
Section 5.03.  Collection of Indebtedness and Suits for Enforcement by Trustee.............60
Section 5.04.  Trustee May File Proofs of Claims...........................................61
</TABLE>



                                      -ii-
<PAGE>   5

<TABLE>
<CAPTION>
                                                                                          Page
                                                                                          ----
<S>                                                                                        <C>
Section 5.05.  Trustee May Enforce Claims Without Possession of Notes......................62
Section 5.06.  Application of Money Collected..............................................63
Section 5.07.  Limitation on Suits.........................................................63
Section 5.08.  Unconditional Right of Holders To Re- ceive Principal, Premium
                   and Interest............................................................64
Section 5.09.  Restoration of Rights and Remedies..........................................64
Section 5.10.  Rights and Remedies Cumulative..............................................65
Section 5.11.  Delay or Omission Not Waiver................................................65
Section 5.12.  Control by Majority.........................................................65
Section 5.13.  Waiver of Past Defaults.....................................................65
Section 5.14.  Undertaking for Costs.......................................................66
Section 5.15.  Waiver of Stay, Extension or Usury Laws.....................................66
Section 5.16.  Unconditional Right of Holders To Receive Payment...........................67

                                   ARTICLE SIX
                                   THE TRUSTEE

Section 6.01.  Certain Duties and Responsibilities.........................................67
Section 6.02.  Notice of Defaults..........................................................68
Section 6.03.  Certain Rights of Trustee...................................................68
Section 6.04.  Trustee Not Responsible for Recitals, Dispositions of Notes or
                   Application of Proceeds Thereof.........................................70
Section 6.05.  Trustee and Agents May Hold Notes; Collections; Etc.........................70
Section 6.06.  Money Held in Trust.........................................................71
Section 6.07.  Compensation and Indemnification of Trustee and Its Prior Claim.............71
Section 6.08.  Conflicting Interests.......................................................72
Section 6.09.  Corporate Trustee Required; Eligibility.....................................72
Section 6.10.  Resignation and Removal; Appointment of Successor Trustee...................72
Section 6.11.  Acceptance of Appointment by Successor......................................74
Section 6.12.  Merger, Conversion, Amalgamation, Consolidation or Succession
                   to Business.............................................................75
</TABLE>



                                      -ii-
<PAGE>   6
<TABLE>
<CAPTION>
                                                                                          Page
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<S>                                                                                        <C>
                                  ARTICLE SEVEN
                HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

Section 7.01.  Preservation of Information; Company To Furnish Trustee Names
                   and Addresses of Holders................................................76
Section 7.02.  Communications of Holders...................................................76
Section 7.03.  Reports by Trustee..........................................................77
Section 7.04.  Reports by Company..........................................................77

                                  ARTICLE EIGHT
                   CONSOLIDATION, MERGER, SALE OF ASSETS, ETC.

Section 8.01.  Company May Consolidate, etc., Only on Certain Terms........................78
Section 8.02.  Successor Substituted.......................................................79

                                  ARTICLE NINE
                       SUPPLEMENTAL INDENTURES AND WAIVERS

Section 9.01.  Supplemental Indentures, Agreements and Waivers Without Consent
                   of Holders..............................................................80
Section 9.02.  Supplemental Indentures, Agreements and Waivers with Consent of
                   Holders.................................................................81
Section 9.03.  Execution of Supplemental Indentures, Agreements and Waivers................82
Section 9.04.  Effect of Supplemental Indentures...........................................82
Section 9.05.  Conformity with Trust Indenture Act.........................................83
Section 9.06.  Reference in Notes to Supplemental Indentures...............................83
Section 9.07.  Record Date.................................................................83
Section 9.08.  Revocation and Effect of Consents...........................................83

                                   ARTICLE TEN
                                    COVENANTS

Section 10.01. Payment of Principal, Premium and Interest..................................84
Section 10.02. Maintenance of Office or Agency.............................................84
</TABLE>



                                      -iv-
<PAGE>   7
<TABLE>
<CAPTION>
                                                                                          Page
                                                                                          ----
<S>                                                                                        <C>
Section 10.03. Money for Note Payments To Be Held in Trust.................................85
Section 10.04. Corporate Existence.........................................................86
Section 10.05. Payment of Taxes and Other Claims...........................................87
Section 10.06. Maintenance of Properties...................................................87
Section 10.07. Insurance...................................................................87
Section 10.08. Books and Records...........................................................88
Section 10.09. Provision of Financial Statements...........................................88
Section 10.10. Change of Control...........................................................88
Section 10.11. Limitation on Additional Indebtedness.......................................91
Section 10.12. Statement by Officers as to Default.........................................91
Section 10.13. Limitation on Restricted Payments...........................................92
Section 10.14. Limitation on Transactions with Affiliates..................................96
Section 10.15. Disposition of Proceeds of Asset Sales......................................98
Section 10.16. Limitation on Liens Securing Certain Indebtedness..........................102
Section 10.17. Limitation on Business.....................................................102
Section 10.18. Limitation on Certain Guarantees and Indebtedness of Restricted
                   Subsidiaries...........................................................102
Section 10.19. Limitation on Issuances and Sales of Preferred Stock by
                   Restricted Sub-sidiaries...............................................103
Section 10.20. Limitation on Dividends and Other Payment Restrictions Affecting
                   Restricted Subsidiaries................................................103
Section 10.21. Limitation on Designations of Unrestricted Subsidiaries....................104
Section 10.22. Compliance Certificates and Opinions.......................................106
Section 10.23. Reports....................................................................106
Section 10.24. Limitation on Status as Investment Company.................................108

                                 ARTICLE ELEVEN
                           SATISFACTION AND DISCHARGE

Section 11.01. Satisfaction and Discharge of Indenture....................................108
Section 11.02. Application of Trust Money.................................................109
</TABLE>



                                      -v-
<PAGE>   8

<TABLE>
<CAPTION>
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<S>                                                                                        <C>
                                 ARTICLE TWELVE
                                   REDEMPTION

Section 12.01. Notices to the Trustee.....................................................109
Section 12.02. Selection of Notes To Be Redeemed..........................................110
Section 12.03. Notice of Redemption.......................................................110
Section 12.04. Effect of Notice of Redemption.............................................111
Section 12.05. Deposit of Redemption Price................................................111
Section 12.06. Notes Redeemed or Purchased in Part........................................112
</TABLE>



Exhibit A-1  -   Form of Series A Note
Exhibit A-2  -   Form of Series B Note
Exhibit B    -   Form of Legend for Book-Entry Securities
Exhibit C    -   Form of Certificate To Be Delivered in Connection with 
                 Transfers to Non-QIB Accredited Investors
Exhibit D    -   Form of Certificate To Be Delivered in Connection with 
                 Transfers Pursuant to Regulation S



                                      -vi-
<PAGE>   9


         INDENTURE, dated as of March 25, 1998, between VERIO INC., a
corporation incorporated under the laws of the State of Delaware (the
"Company"), as issuer, and FIRST TRUST NATIONAL ASSOCIATION, as trustee (the
"Trustee").

                                    RECITALS

         The Company has duly authorized the creation of an issue of (i) 10-3/8%
Senior Notes Due 2005, Series A, and (ii) 10-3/8% Senior Notes Due 2005, Series
B, to be issued in exchange for the 10-3/8% Senior Notes Due 2005, Series A,
pursuant to the Registration Rights Agreement (the "Notes"; such term to include
the Initial Notes, the Private Exchange Notes, if any, and the Unrestricted
Notes, if any, treated as a single class of securities under this Indenture), of
substantially the tenor and amount hereinafter set forth, and to provide
therefor the Company has duly authorized the execution and delivery of this
Indenture.

         All things necessary have been done to make the Notes, when executed by
the Company, and authenticated and delivered hereunder and duly issued by the
Company, the valid obligations of the Company and to make this Indenture a valid
agreement of each of the Company and the Trustee in accordance with the terms
hereof.

         NOW, THEREFORE, THIS INDENTURE WITNESSETH:

         For and in consideration of the premises and the purchase of the Notes
by the Holders (as hereinafter defined) thereof, it is mutually covenanted and
agreed, for the equal and proportionate benefit of all Holders of the Notes, as
follows:


                                   ARTICLE ONE

             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION


         Section 1.01. Definitions.

         "1997 Notes" means the Company's 13-1/2% Senior Notes due 2004.

         "Acquired Indebtedness" means Indebtedness of a person existing at the
time such person becomes a Restricted Subsidiary




<PAGE>   10
                                      -2-


or assumed in connection with an Asset Acquisition by such person and not
incurred in connection with, or in anticipation of, such person becoming a
Restricted Subsidiary or such Asset Acquisition; provided that Indebtedness of
such person which is redeemed, defeased, retired or otherwise repaid at the time
of or immediately upon consummation of the transactions by which such person
becomes a Restricted Subsidiary or such Asset Acquisition shall not constitute
Acquired Indebtedness.

         "Affiliate" of any specified person means any other person which,
directly or indirectly, controls, is controlled by or is under direct or
indirect common control with such specified person. For the purposes of this
definition, "control" when used with respect to any person means the power to
direct the management and policies of such person, directly or indirectly,
whether through the ownership of voting securities, by contract or otherwise,
and the terms "affiliated," "controlling" and "controlled" have meanings
correlative to the foregoing.

         "Annualized ISP Revenues" means, with respect to any ISP at any date of
determination, the consolidated net revenues of such ISP and its Subsidiaries
for the most recent quarter for which financial information concerning such ISP
is available (and determined on a basis consistent with the Company's accounting
principles) multiplied by four.

         "Asset Acquisition" means (i) any capital contribution (by means of
transfers of cash or other property to others or payments for property or
services for the account or use of others, or otherwise) by the Company or any
Restricted Subsidiary in any other person, or any acquisition or purchase of
Capital Stock of any other person by the Company or any Restricted Subsidiary,
in either case pursuant to which such person shall (a) become a Restricted
Subsidiary or (b) shall be merged with or into the Company or any Restricted
Subsidiary or (ii) any acquisition by the Company or any Restricted Subsidiary
of the assets of any person which constitute substantially all of an operating
unit or line of business of such person or which is otherwise outside of the
ordinary course of business.

         "Asset Sale" means any direct or indirect sale, conveyance, transfer or
lease (that has the effect of a disposition and is not for security purposes) or
other disposition (that is not for security purposes) to any person other than
the Company or a Restricted Subsidiary, in one transaction or a series of
related transactions, of (i) any Capital Stock of any Restricted Subsidiary
(other than customary stock option programs),



<PAGE>   11
                                      -3-


(ii) any assets of the Company or any Restricted Subsidiary which constitute
substantially all of an operating unit or line of business of the Company and
the Restricted Subsidiaries or (iii) any other property or asset of the Company
or any Restricted Subsidiary outside of the ordinary course of business. For the
purposes of this definition, the term "Asset Sale" shall not include (i) any
disposition of properties and assets of the Company that is governed under
Article Eight, (ii) sales of property or equipment that have become worn out,
obsolete or damaged or otherwise unsuitable for use in connection with the
business of the Company or any Restricted Subsidiary, as the case may be, and
(iii) for purposes of Section 10.15 hereof, any sale, conveyance, transfer,
lease or other disposition of any property or asset, whether in one transaction
or a series of related transactions occurring within one year, either (x)
involving assets with a Fair Market Value not in excess of $500,000 or (y) which
constitutes the incurrence of a Capitalized Lease Obligation.

         "Average Life to Stated Maturity" means, with respect to any
Indebtedness, as at any date of determination, the quotient obtained by dividing
(i) the sum of the products of (a) the number of years from such date to the
date or dates of each successive scheduled principal payment (including, without
limitation, any sinking fund requirements) of such Indebtedness multiplied by
(b) the amount of each such principal payment by (ii) the sum of all such
principal payments; provided that, in the case of any Capitalized Lease
Obligation, all calculations hereunder shall give effect to any applicable
options to renew in favor of the Company or any Restricted Subsidiary.

         "Bankruptcy Law" means Title 11, United States Code or any similar
federal or state law relating to bankruptcy, insolvency, receivership,
winding-up, liquidation, reorganization or relief of debtors or the law of any
other jurisdiction relating to bankruptcy, insolvency, receivership, winding-up,
liquidation, reorganization or relief of debtors or any amendment to, succession
to or change in any such law.

         "Bankruptcy Order" means any court order made in a proceeding pursuant
to or within the meaning of any Bankruptcy Law, containing an adjudication of
bankruptcy or insolvency, or providing for liquidation, receivership,
winding-up, dissolution, "concordate" or reorganization, or appointing a
Custodian of a debtor or of all or any substantial part of a debtor's property,
or providing for the staying, arrangement, adjustment or composition of
indebtedness or other relief of a debtor.

<PAGE>   12
                                      -4-


         "Board" means the Board of Directors of the Company.

         "Board Resolution" means a copy of a resolution certified by the
Secretary or an Assistant Secretary of the Company to have been duly adopted by
the Board and to be in full force and effect on the date of such certification,
and delivered to the Trustee.

         "Business Day" means each Monday, Tuesday, Wednesday, Thursday and
Friday which is not a day on which banking institutions in The City of New York,
New York or St. Paul, Minnesota are authorized or obligated by law, regulation
or executive order to close.

         "Capital Stock" means, with respect to any person, any and all shares,
interests, participations, rights in, or other equivalents (however designated
and whether voting and/or non-voting) of, such person's capital stock, whether
outstanding on the Issue Date or issued after the Issue Date, and any and all
rights (other than any evidence of Indebtedness), warrants or options
exchangeable for or convertible into such capital stock.

         "Capitalized Lease Obligation" means any obligation to pay rent or
other amounts under a lease of (or other agreement conveying the right to use)
any property (whether real, personal or mixed, immovable or movable) that is
required to be classified and accounted for as a capitalized lease obligation
under GAAP, and for the purpose of this Indenture, the amount of such obligation
at any date shall be the capitalized amount thereof at such date, determined in
accordance with GAAP.

         "Cash Equivalents" means (i) any evidence of Indebtedness (with, for
purposes of Section 10.15 hereof only, a maturity of 365 days or less) issued or
directly and fully guaranteed or insured by the United States or any agency or
instrumentality thereof (provided that the full faith and credit of the United
States is pledged in support thereof or such Indebtedness constitutes a general
obligation of such country); (ii) deposits, certificates of deposit or
acceptances (with, for purposes of Section 10.15 hereof only, a maturity of 365
days or less) of any financial institution that is a member of the Federal
Reserve System, in each case having combined capital and surplus and undivided
profits (or any similar capital concept) of not less than $500.0 million and
whose senior unsecured debt is rated at least "A-1" by S&P or "P-1" by Moody's;
(iii) commercial paper with a maturity of 365 days or less issued by a
corporation (other than an Affiliate of the Company)




<PAGE>   13
                                      -5-


organized under the laws of the United States or any State thereof and rated at
least "A-1" by S&P or "P-1" by Moody's; (iv) repurchase agreements and reverse
repurchase agreements relating to marketable direct obligations issued or
unconditionally guaranteed by the United States Government or issued by any
agency thereof and backed by the full faith and credit of the United States
Government maturing within 365 days from the date of acquisition; (v) other debt
obligations maturing in 365 days or less issued by a corporation (other than an
Affiliate of the Company)organized under the laws of the United States or any
state thereof and rated at least "A-" by S&P or "A3" by Moody's; and (vi) money
market funds which invest substantially all of their assets in securities of the
type described in the preceding clauses (i) through (v).

         "Change of Control" means the occurrence of any of the following
events: (a) any "person" or "group" (as such terms are used in Sections 13(d)
and 14(d) of the Exchange Act), excluding WorldCom, is or becomes the
"beneficial owner" (as defined in Rules 13d-3 and 13d-5 under the Exchange Act,
except that a person shall be deemed to have "beneficial ownership" of all
securities that such person has the right to acquire, whether such right is
excercisable immediately or only after the passage of time), directly or
indirectly, of more than 50% of the total Voting Stock of the Company; or (b)
the Company consolidates with, or merges with or into, another person or sells,
assigns, conveys, transfers, leases or otherwise disposes of all or
substantially all of its assets to any person, or any person consolidates with,
or merges with or into, the Company, in any such event pursuant to a transaction
in which the outstanding Voting Stock of the Company is converted into or
exchanged for cash, securities or other property, other than any such
transaction where (i) the outstanding Voting Stock of the Company is converted
into or exchanged for (1) Voting Stock (other than Disqualified Stock) of the
surviving or transferee corporation or its parent corporation and/or (2) cash,
securities and other property in an amount which could be paid by the Company as
a Restricted Payment under this Indenture and (ii) immediately after such
transaction no "person" or "group" (as such terms are used in Section 13(d) and
14(d) of the Exchange Act), excluding WorldCom, is the "beneficial owner" (as
defined in Rules 13d-3 and 13d-5 under the Exchange Act, except that a person
shall be deemed to have "beneficial ownership" of all securities that such
person has the right to acquire, whether such right is excercisable immediately
or only after the passage of time), directly or indirectly, of more than 50% of
the total Voting Stock of the surviving or transferee corporation or its parent
corporation, as applicable; or




<PAGE>   14
                                      -6-


(c) during any consecutive two-year period, individuals who at the beginning of
such period constituted the Board (together with any new directors whose
election by the Board or whose nomination for election by the stockholders of
the Company was approved by a vote of a majority of the directors then still in
office who were either directors at the beginning of such period or whose
election or nomination for election was previously so approved) cease for any
reason (other than by action of WorldCom) to constitute a majority of the Board
then in office. The good faith determination by the Board, based upon advice of
outside counsel, of the beneficial ownership of securities of the Company within
the meaning of Rules 13d-3 and 13d-5 under the Exchange Act shall be conclusive,
absent contrary controlling judicial precedent or contrary written
interpretation published by the SEC.

         "Common Stock" means, with respect to any person, any and all shares,
interests or other participations in, and other equivalents (however designated
and whether voting or non-voting) of such person's common stock whether
outstanding at the Issue Date, and includes, without limitation, all series and
classes of such common stock.

         "Company" means the person named as the "Company" in the first
paragraph of this Indenture, until a successor person shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Company" shall mean such successor person.

         "Company Request" or "Company Order" means a written request or order
signed in the name of the Company by any one of its Chairman of the Board, its
Vice-Chairman, its Chief Executive Officer, its President or a Vice President,
and by its Secretary or an Assistant Secretary or the Treasurer or an Assistant
Treasurer, and delivered to the Trustee.

         "Consolidated Annualized Pro Forma Operating Cash Flow" means, at any
date of determination, Consolidated Operating Cash Flow for the latest fiscal
quarter for which consolidated financial statements of the Company are available
multiplied by four. For purposes of calculating "Consolidated Operating Cash
Flow" for any fiscal quarter for purposes of this definition, (i) any Subsidiary
of the Company that is a Restricted Subsidiary on the date of the transaction
(the "Transaction Date") giving rise to the need to calculate "Consolidated
Annualized Pro Forma Operating Cash Flow" shall be deemed to have been a
Restricted Subsidiary at all times during such fiscal quarter and (ii) any
Subsidiary of the Company that is



<PAGE>   15
                                      -7-


not a Restricted Subsidiary on the Transaction Date shall be deemed not to have
been a Restricted Subsidiary at any time during such fiscal quarter. In addition
to and without limitation of the foregoing, for purposes of this definition,
"Consolidated Operating Cash Flow" shall be calculated after giving effect on a
pro forma basis for the applicable fiscal quarter to, without duplication, any
Asset Sales or Asset Acquisitions (including, without limitation, any Asset
Acquisition giving rise to the need to make such calculation as a result of the
Company or one of the Restricted Subsidiaries (including any person who becomes
a Restricted Subsidiary as a result of the Asset Acquisition) incurring,
assuming or otherwise being liable for Acquired Indebtedness) occurring during
the period commencing on the first day of such fiscal quarter to and including
the Transaction Date, as if such Asset Sale or Asset Acquisition occurred on the
first day of such fiscal quarter.

         "Consolidated Income Tax Expense" means, with respect to any period,
the provision for United States corporation, local, foreign and other income
taxes of the Company and the Restricted Subsidiaries for such period as
determined on a consolidated basis in accordance with GAAP.

         "Consolidated Interest Expense" means, with respect to any period,
without duplication, the sum of (i) the interest expense of the Company and the
Restricted Subsidiaries for such period as determined on a consolidated basis in
accordance with GAAP, including, without limitation, (a) any amortization of
debt discount, (b) the net cost under Interest Rate Obligations (including any
amortization of discounts), (c) the interest portion of any deferred payment
obligation, (d) all commissions, discounts and other fees and charges owed with
respect to letters of credit and bankers' acceptance financing and similar
transactions and (e) all accrued interest, (ii) the interest component of
Capitalized Lease Obligations paid, accrued and/or scheduled to be paid or
accrued by the Company and the Restricted Subsidiaries during such period as
determined on a consolidated basis in accordance with GAAP and (iii) the amount
of dividends in respect of Disqualified Stock paid by the Company and the
Restricted Subsidiaries during such period; provided that Consolidated Interest
Expense shall exclude the amortization of fees related to the issuance of the
Notes and fees related to any Indebtedness under a Permitted Credit Facility.

         "Consolidated Net Income" means, with respect to any period, the
consolidated net income of the Company and the Restricted Subsidiaries for such
period, adjusted, to the extent




<PAGE>   16
                                      -8-


included in calculating such consolidated net income, by excluding, without
duplication, (i) all extraordinary, unusual or nonrecurring gains or losses of
such person (net of fees and expenses relating to the transaction giving rise
thereto) for such period, (ii) income of the Company and the Restricted
Subsidiaries derived from or in respect of all Investments in persons other than
Restricted Subsidiaries, except to the extent of any dividends or distributions
actually received by the Company or any Restricted Subsidiary, (iii) the portion
of net income (or loss) of such person allocable to minority interests in
Restricted Subsidiaries for such period, (iv) net income (or loss) of any other
person combined with such person on a "pooling of interests" basis attributable
to any period prior to the date of combination, (v) any gain or loss, net of
taxes, realized by such person upon the termination of any employee pension
benefit plan during such period, (vi) gains or losses in respect of any Asset
Sales (net of fees and expenses relating to the transaction giving rise thereto)
during such period and (vii) except in the case of any restriction or
encumbrance permitted under clause (viii) of Section 10.20 hereof, the net
income of any Restricted Subsidiary for such period to the extent that the
declaration of dividends or similar distributions by that Restricted Subsidiary
of that income is not at the time permitted, directly or indirectly, by
operation of the terms of its charter or any agreement, instrument, judgment,
decree, order, statute, rule or governmental regulations applicable to that
Restricted Subsidiary or its stockholders.

         "Consolidated Net Worth" means, with respect to any person, the
consolidated stockholders' or partners' equity of such person reflected on the
most recent financial statements of such person, determined in accordance with
GAAP, less any amounts attributable to redeemable capital stock (as determined
under applicable accounting standards by the SEC) of such person.

         "Consolidated Operating Cash Flow" means, with respect to any period,
the Consolidated Net Income of the Company and the Restricted Subsidiaries for
such period increased, to the extent deducted in arriving at Consolidated Net
Income for such period, by the sum of (i) the Consolidated Income Tax Expense of
the Company and the Restricted Subsidiaries accrued according to GAAP for such
period (other than taxes attributable to extraordinary gains or losses and gains
and losses from Asset Sales); (ii) Consolidated Interest Expense for such
period; (iii) depreciation of the Company and the Restricted Subsidiaries for
such period; (iv) amortization of the Company and the Restricted Subsidiaries
for such period, including, without



<PAGE>   17
                                      -9-


limitation, amortization of capitalized debt issuance costs for such period, all
determined on a consolidated basis in accordance with GAAP; and (v) other
non-cash charges decreasing Consolidated Net Income.

         "consolidation" means, with respect to the Company, the consolidation
of the accounts of the Restricted Subsidiaries with those of the Company, all in
accordance with GAAP; provided that "consolidation" will not include
consolidation of the accounts of any Unrestricted Subsidiary with the accounts
of the Company. The term "consolidated" has a correlative meaning to the
foregoing.

         "Corporate Trust Office" means the office of the Trustee at which at
any particular time its corporate trust business shall be principally
administered, which office at the date of execution of this Indenture is located
at 180 East 5th Street, St. Paul, Minnesota 55101, Attention: Corporate Trust
Department, except for purposes of Sections 3.02 and 10.02 hereof. For purposes
of such sections, such office is located at 100 Wall Street, 20th Floor, New
York, New York 10005.

         "Custodian" means any receiver, interim receiver, receiver and manager,
receiver-manager, trustee, assignee, liquidator, sequestrator or similar
official under any Bankruptcy Law or any other law respecting secured creditors
and the enforcement of their security or any other person with like powers
whether appointed judicially or out of court and whether pursuant to an interim
or final appointment.

         "Debt Securities" means any debt securities issued by the Company in a
public offering or a private placement.

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

         "Depository" means The Depository Trust Company, its nominees and
successors.

         "Designation" has the meaning set forth under Section 10.21 hereof.

         "Disinterested Director" means, with respect to any transaction or
series of related transactions, a member of the Board other than a director who
(i) has any material direct or indirect financial interest in or with respect to
such transaction or series of related transactions or (ii) is an employee or
officer of the Company or an Affiliate that is itself a



<PAGE>   18
                                      -10-


party to such transaction or series of transactions or an Affiliate of a party
to such transaction or series of related transactions.

         "Disqualified Stock" means, with respect to any person, any Capital
Stock which, by its terms (or by the terms of any security into which it is
convertible or for which it is exchangeable), or upon the happening of any
event, matures or becomes mandatorily redeemable, pursuant to a sinking fund
obligation or otherwise, or becomes exchangeable for Indebtedness at the option
of the holder thereof, or becomes redeemable at the option of the holder
thereof, in whole or in part, on or prior to the final maturity date of the
Notes; provided such Capital Stock shall only constitute Disqualified Stock to
the extent it so matures or becomes so redeemable or exchangeable on or prior to
the final maturity date of the Notes; provided, further, 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 final maturity date of the Notes shall not constitute
Disqualified Stock if the "asset sale" or "change of control" provisions
applicable to such Capital Stock are no more favorable to the holders of such
Capital Stock than the provisions contained in Section 10.15 and Section 10.10
hereof described above and such Capital Stock specifically provides that such
person will not repurchase or redeem any such stock pursuant to such provision
prior to the Company's repurchase of such Notes as are required to be
repurchased pursuant to Section 10.15 and Section 10.10 hereof.

         "Euroclear" means Morgan Guaranty Trust Company of New York, Brussels
Office, as operator of the Euroclear System.

         "Exchange Act" means the Securities Exchange Act of 1934, as amended,
together with the rules and regulations promulgated thereunder.

         "Exchange Notes" means the 10-3/8% Senior Notes Due 2005, Series B, to
be issued in exchange for the Initial Notes pursuant to the Registration Rights
Agreement.

         "Exchange Offer" shall have the meaning specified in the Registration
Rights Agreement.

         "Existing ISP" means any ISP in which the Company or a Subsidiary of
the Company has an Investment on the Issue Date.


<PAGE>   19
                                      -11-


         "Fair Market Value" means, with respect to any asset or property, the
price that could be negotiated in an arm's-length free market transaction, for
cash, between a willing seller and a willing buyer, neither of whom is under
pressure or compulsion to complete the transaction. Unless otherwise specified
in this Indenture, Fair Market Value shall be determined by the Board acting in
good faith and shall be evidenced by a Board Resolution.

         "GAAP" means, at any date of determination, generally accepted
accounting principles in effect in the United States and which are applicable as
of the date of determination and which are consistently applied for all
applicable periods.

         "Global Notes" means one or more Regulation S Global Notes and 144A
Global Notes.

         "guarantee" means, as applied to any obligation, (i) a guarantee (other
than by endorsement of negotiable instruments for collection in the ordinary
course of business), direct or indirect, in any manner, of any part or all of
such obligation and (ii) an agreement, direct or indirect, contingent or
otherwise, the practical effect of which is to assure in any way the payment or
performance (or payment of damages in the event of non-performance) of all or
any part of such obligation, including, without limiting the foregoing, the
payment of amounts drawn down by letters of credit.

         "Guarantee" has the meaning provided in Section 10.18.

         "Guarantor" has the meaning provided in Section 10.18.

         "Holder" or "Noteholder" means a person in whose name a Note is
registered in the Note Register.

         "incur" means, with respect to any Indebtedness or other obligation of
any person, to create, issue, incur (by conversion, exchange or otherwise),
assume, guarantee or otherwise become liable in respect of such Indebtedness or
other obligation including by acquisition of Subsidiaries or the recording, as
required pursuant to GAAP or otherwise, of any such Indebtedness or other
obligation on the balance sheet of such person (and "incurrence," "incurred,"
"incurrable" and "incurring" shall have meanings correlative to the foregoing);
provided that a change in GAAP that results in an obligation of such person that
exists at such time becoming Indebtedness


<PAGE>   20
                                      -12-


shall not be deemed an incurrence of such Indebtedness and that neither the
accrual of interest nor the accretion of original issue discount shall be deemed
an incurrence of Indebtedness. Indebtedness otherwise incurred by a person
before it becomes a Subsidiary of the Company (whether by merger, consolidation,
acquisition or otherwise) shall be deemed to have been incurred at the time at
which such person becomes a Subsidiary of the Company.

         "Indebtedness" means, with respect to any person, without duplication,
(i) any liability, contingent or otherwise, of such person (A) for borrowed
money (whether or not the recourse of the lender is to the whole of the assets
of such person or only to a portion thereof) or (B) evidenced by a note,
debenture or similar instrument or letter of credit (including a purchase money
obligation) or (C) for the payment of money relating to a Capitalized Lease
Obligation or other obligation relating to the deferred purchase price of
property (except to the extent representing funds deposited in escrow to secure
the deferred purchase price of an acquisition of, or an Investment in, an ISP)
or (D) in respect of an Interest Rate Obligation or currency agreement; or (ii)
any liability of others of the kind described in the preceding clause (i) which
the person has guaranteed or which is otherwise its legal liability; or (iii)
any obligation secured by a Lien (other than (x) Permitted Liens of the types
described in clauses (b), (d) or (e) of the definition of Permitted Liens;
provided that the obligations secured would not constitute Indebtedness under
clauses (i) or (ii) or (iii) of this definition, and (y) Liens on Capital Stock
or Indebtedness of any Unrestricted Subsidiary) to which the property or assets
of such person are subject, whether or not the obligations secured thereby shall
have been assumed by or shall otherwise be such person's legal liability (the
amount of such obligation being deemed to be the lesser of the value of such
property or asset or the amount of the obligation so secured); (iv) all
Disqualified Stock valued at the greater of its voluntary or involuntary maximum
fixed repurchase price plus accrued and unpaid dividends; and (v) any and all
deferrals, renewals, extensions and refundings of, or amendments, modifications
or supplements to, any liability of the kind described in any of the preceding
clauses (i), (ii), (iii) or (iv). In no event shall "Indebtedness" include trade
payables and accrued liabilities that are current liabilities incurred in the
ordinary course of business, excluding the current maturity of any obligation
which would otherwise constitute Indebtedness. For purposes of Section 10.11 and
Section 10.13 hereof and the definition of "Events of Default," in determining
the principal amount of any Indebtedness to be incurred


<PAGE>   21
                                      -13-


by the Company or a Restricted Subsidiary or which is outstanding at any date,
(x) the principal amount of any Indebtedness issued with original issue discount
shall be the face amount of such Indebtedness less the remaining unamortized
portion of the original issue discount of such Indebtedness at such date as
determined in conformity with GAAP and (y) the principal amount of any
Indebtedness shall be reduced by any amount of cash or Cash Equivalent
collateral securing on a perfected basis, and dedicated for disbursement
exclusively to the payment of principal of and interest on, such Indebtedness.

         "Indenture" means this instrument as originally executed (including all
exhibits and schedules hereto) and as it may from time to time be supplemented
or amended by one or more indentures supplemental hereto entered into pursuant
to the applicable provisions hereof.

         "Indenture Obligations" means the obligations of the Company and any
other obligor under this Indenture or under the Notes, to pay principal of,
premium, if any, and interest on the Notes when due and payable, whether at
maturity, by acceleration, call for redemption or repurchase or otherwise, and
all other amounts due or to become due under or in connection with this
Indenture or the Notes and the performance of all other obligations to the
Trustee (including, but not limited to, payment of all amounts due the Trustee
under Section 6.07 hereof) and the Holders of the Notes under this Indenture and
the Notes, according to the terms thereof.

         "Independent Financial Advisor" means a United States investment
banking firm of national or regional standing in the United States (i) which
does not, and whose directors, officers and employees or Affiliates do not have,
a direct or indirect financial interest in the Company and (ii) which, in the
judgment of the Board, is otherwise independent and qualified to perform the
task for which it is to be engaged.

         "Initial Notes" means the 10-3/8% Senior Notes Due 2005, Series A, of
the Company.

         "Initial Purchasers" means Salomon Brothers Inc, Lazard Freres & Co.
LLC, Chase Securities Inc. and BancBoston Securities Inc.

         "Institutional Accredited Investor" means an institution that is an
"accredited investor" as that term is defined in Rule 501(a)(1), (2), (3) or (7)
under the Securities Act.



<PAGE>   22
                                      -14-


         "interest", when used with respect to any Note, means the amount of all
interest accruing on such Note, including all additional interest payable on the
Notes pursuant to the Registration Rights Agreement and all interest accruing
subsequent to the occurrence of any events specified in Sections 5.01(viii),
(ix) and (x) hereof or which would have accrued but for any such event, whether
or not such claims are allowable under applicable law.

         "Interest Payment Date" means, when used with respect to any Note, the
Stated Maturity of an installment of interest on such Note, as set forth in such
Note.

         "Interest Rate Obligations" means the obligations of any person
pursuant to any arrangement with any other person whereby, directly or
indirectly, such person is entitled to receive from time to time periodic
payments calculated by applying either a floating or a fixed rate of interest on
a stated notional amount and shall include without limitation, interest rate
swaps, caps, floors, collars, forward interest rate agreements and similar
agreements.

         "Internet Service Business" means any business operating an internet
connectivity or internet enhancement service as it exists from time to time,
including, without limitation, dial up or dedicated internet service, web
hosting or collocation services, security solutions, the provision and
development of software in connection therewith, configuration services,
electronic commerce, intranet solutions, data backup and restoral, business
content and collaboration, communications tools or network equipment products or
services (including, without limitation, any business conducted by the Company
or any Restricted Subsidiary on the Issue Date), and any business reasonably
related to the foregoing. A good faith determination by a majority of the Board
as to whether a business meets the requirements of this definition shall be
conclusive, absent manifest error.

         "Investment" means, with respect to any person, any advance, loan,
account receivable (other than an account receivable arising in the ordinary
course of business), or other extension of credit (including, without
limitation, by means of any guarantee) or any capital contribution to (by means
of transfers of property to others, payments for property or services for the
account or use of others, or otherwise), or any purchase or ownership of any
stocks, bonds, notes, debentures or other securities of, any other person.
Notwithstanding the foregoing, in no event shall any issuance of Capital Stock




<PAGE>   23
                                      -15-


(other than Disqualified Stock) of the Company in exchange for Capital Stock,
property or assets of another person constitute an Investment by the Company in
such other person.

         "ISP" means any person (a) engaged principally in an Internet Service
Business, (b) of which the Company or Wholly Owned Restricted Subsidiaries own
either (x) Qualifying Preferred Stock representing in aggregate from 20% to 50%
of such person's outstanding Capital Stock (on an economic basis) or (y) Common
Stock or Qualifying Preferred Stock representing in aggregate in excess of 50%
of such person's voting Capital Stock, (c) as to which the Company or a Wholly
Owned Restricted Subsidiary has an option, either immediately exercisable or
exercisable commencing after one year (subject to extension under limited
circumstances consistent with past practice) of the Investment made by the
Company or a Wholly Owned Restricted Subsidiary, to acquire all of such person's
outstanding Capital Stock, (d) as to which the Company or a Wholly Owned
Restricted Subsidiary is the beneficiary of a right of first refusal or other
transfer restrictions generally limiting transfers of such person's Capital
Stock by third parties, (e) as to which the Company or a Wholly Owned Restricted
Subsidiary has the right to appoint and has appointed at least one member of
such person's board of directors, in the case where such person would not be a
Subsidiary of the Company, or a majority of such person's board of directors, in
the case where such person would be a Subsidiary of the Company and (f) which
has no outstanding Capital Stock or Indebtedness other than (i) Common Stock or
options to acquire Common Stock, (ii) Qualifying Preferred Stock held by the
Company or a Wholly Owned Restricted Subsidiary, (iii) rights granted to other
stockholders to acquire Capital Stock of such person from the Company or its
affiliates in certain circumstances, (iv) preferred stock ranking junior in a
liquidation to any Qualifying Preferred Stock referred to in clause (ii), and
(v) Indebtedness of such person or preferred stock of such person ranking prior
in a liquidation or deemed liquidation to the Qualifying Preferred Stock
referred to in clause (ii) having an aggregate outstanding principal balance and
liquidation preference, respectively, that (x) in the case of a person that is a
Restricted Subsidiary, is permitted to be incurred under Section 10.11 hereof
and (y) in the case of a person that is not a Restricted Subsidiary, does not at
any time exceed 50% of Annualized ISP Revenues.

         "Issue Date" means the original date of issuance of the Notes.



<PAGE>   24
                                      -16-


         "Lien" means any mortgage, charge, pledge, lien (statutory or other),
security interest, hypothecation, assignment for security, claim, or preference
or priority or other encumbrance upon or with respect to any property of any
kind. A person shall be deemed to own subject to a Lien any property which such
person has acquired or holds subject to the interest of a vendor or lessor under
any conditional sale agreement, capital lease or other title retention
agreement.

         "Market Capitalization" of any person means, as of any day of
determination, the average Closing Price of such person's Common Stock over the
20 consecutive trading days immediately preceding such day. "Closing Price" on
any trading day with respect to the per share price of any shares of Common
Stock means the last reported sale price regular way or, in case no such
reported sale takes place on such day, the average of the reported closing bid
and asked prices regular way, in either case on the New York Stock Exchange or,
if such shares of Common Stock are not listed or admitted to trading on such
exchange, on the principal national securities exchange on which such shares are
listed or admitted to trading or, if not listed or admitted to trading on any
national securities exchange, on the National Association of Securities Dealers
Automated Quotations National Market System or, if such shares are not listed or
admitted to trading on any national securities exchange or quoted on such
automated quotation system but the issuer is a Foreign Company (as defined in
Rule 3b-4(b) under the Exchange Act) and the principal securities exchange on
which such shares are listed or admitted to trading is a Designated Offshore
Securities Market (as defined in Rule 902(a) under the Securities Act), the
average of the reported closing bid and asked prices regular way on such
principal exchange, or, if such shares are not listed or admitted to trading on
any national securities exchange or quoted on such automated quotation system
and the issuer and principal securities exchange do not meet such requirements,
the average of the closing bid and asked prices in the over-the-counter marked
as furnished by any New York Stock Exchange member firm that is selected from
time to time by the Company for that purpose and is reasonably acceptable to the
Trustee.

         "Material Restricted Subsidiary" means any Restricted Subsidiary of the
Company, which, at any date of determination, is a "Significant Subsidiary" (as
that term is defined in Regulation S-X issued under the Securities Act), but
shall, in any event, include (x) any Guarantor or (y) any Restricted Subsidiary
of the Company which, at any date of determination, is an



<PAGE>   25
                                      -17-


obligor under any Indebtedness in an aggregate principal amount equal to or
exceeding $7.5 million.

         "Maturity Date" means, with respect to any Note, the date specified in
such Note as the fixed date on which the principal of such Note is due and
payable.

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

         "Net Cash Proceeds" means, with respect to any Asset Sale, the proceeds
thereof in the form of cash (including assumed liabilities and other items
deemed to be cash under the proviso to the first sentence of Section 10.15
hereof) or Cash Equivalents including payments in respect of deferred payment
obligations when received in the form of cash or Cash Equivalents (except to the
extent that such obligations are financed or sold with recourse to the Company
or any Restricted Subsidiary) net of (i) brokerage commissions and other fees
and expenses (including fees and expenses of legal counsel and investment
bankers) related to such Asset Sale, (ii) provisions for all taxes payable as a
result of such Asset Sale, (iii) amounts required to be paid to any person
(other than the Company or any Restricted Subsidiary) owning a beneficial
interest in or having a Permitted Lien on the assets subject to the Asset Sale
and (iv) appropriate amounts to be provided by the Company or any Restricted
Subsidiary, as the case may be, as a reserve required in accordance with GAAP
against any liabilities associated with such Asset Sale and retained by the
Company or any Restricted Subsidiary, as the case may be, after 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
reflected in an Officers' Certificate delivered to the Trustee.

         "New ISP" means any ISP in which the Company or a Subsidiary of the
Company makes its first Investment after the Issue Date.

         "Non-U.S. Person" has the meaning assigned to such term in Regulation
S.

         "Notes" shall have the meaning specified in the recitals of this
Indenture.

         "Offering Memorandum" means the Offering Memorandum dated March 19,
1998 pursuant to which the Notes were offered, and any supplement thereto.



<PAGE>   26
                                      -18-


         "Officer" means, with respect to the Company, the Chairman of the
Board, a Vice Chairman, the President, a Vice President, the Secretary, an
Assistant Secretary, the Treasurer or an Assistant Treasurer.

         "Officers' Certificate" means a certificate signed by the Chairman of
the Board, a Vice Chairman, the President or a Vice President, and by the
Secretary, an Assistant Secretary, the Treasurer or an Assistant Treasurer, of
the Company and delivered to the Trustee.

         "144A Global Note" means a permanent global note in registered form
representing the aggregate principal amount of Notes sold in reliance on Rule
144A under the Securities Act.

         "Opinion of Counsel" means a written opinion of counsel, who may be
counsel for the Company or the Trustee, and who shall be reasonably acceptable
to the Trustee.

         "Other Senior Debt Pro Rata Share" means the amount of the applicable
Excess Proceeds obtained by multiplying the amount of such Excess Proceeds by a
fraction, (i) the numerator of which is the aggregate accreted value and/or
principal amount, as the case may be, of all Indebtedness (other than (x) the
Notes and (y) Subordinated Indebtedness) of the Company outstanding at the time
of the applicable Asset Sale with respect to which the Company is required to
use Excess Proceeds to repay or make an offer to purchase or repay and (ii) the
denominator of which is the sum of (a) the aggregate principal amount of all
Notes Outstanding at the time of the applicable Asset Sale and (b) the aggregate
principal amount or the aggregate accreted value, as the case may be, of all
other Indebtedness (other than Subordinated Indebtedness) of the Company
outstanding at the time of the applicable Asset Sale Offer with respect to which
the Company is required to use the applicable Excess Proceeds to offer to repay
or make an offer to purchase or repay.

         "Outstanding" means, as of the date of determination, all Notes
theretofore authenticated and delivered under this Indenture, except:

         (i)   Notes theretofore canceled by the Trustee or delivered to the 
   Trustee for cancellation;

         (ii)  Notes, or portions thereof, for whose payment or redemption money
   in the necessary amount has been theretofore deposited with the Trustee or
   any Paying Agent (other 



<PAGE>   27
                                      -19-


   than the Company or any Affiliate thereof) in trust or set aside and 
   segregated in trust by the Company or any Affiliate thereof (if the Company 
   or such Affiliate shall act as Paying Agent) for the Holders of such Notes; 
   provided, however, that if such Notes are to be redeemed, notice of such 
   redemption has been duly given pursuant to this Indenture or provision 
   therefor satisfactory to the Trustee has been made;

         (iii) Notes with respect to which the Company has effected defeasance

    or covenant defeasance as provided in Article Four, to the extent provided
    in Sections 4.02 and 4.03 hereof; and

         (iv)  Notes in exchange for or in lieu of which other Notes have been 
   authenticated and delivered pursuant to this Indenture, other than any such 
   Notes in respect of which there shall have been presented to the Trustee
   proof satisfactory to it that such Notes are held by a bona fide purchaser in
   whose hands the Notes are valid obligations of the Company;

provided, however, that in determining whether the Holders of the requisite
principal amount of Outstanding Notes have given any request, demand,
authorization, direction, notice, consent or waiver hereunder, Notes owned by
the Company or any other obligor upon the Notes or any Affiliate of the Company
or such other obligor shall be disregarded and deemed not to be Outstanding,
except that, in determining whether the Trustee shall be protected in relying
upon any such request, demand, authorization, direction, notice, consent or
waiver, only Notes that a Responsible Officer of the Trustee knows to be so
owned shall be so disregarded. The Company shall notify the Trustee, in writing,
when it repurchases or otherwise acquires Notes, of the aggregate principal
amount of such Notes so repurchased or otherwise acquired. Notes so owned which
have been pledged in good faith may be regarded as Outstanding if the pledgee
establishes to the satisfaction of the Trustee the pledgee's right so to act
with respect to such Notes and that the pledgee is not the Company or any other
obligor upon the Notes or any Affiliate of the Company or such other obligor. If
the Paying Agent holds, in its capacity as such, on any Maturity Date or on any
optional redemption date money sufficient to pay all accrued interest and
principal with respect to such Notes payable on that date and is not prohibited
from paying such money to the Holders thereof pursuant to the terms of this
Indenture, then on and after that date such Notes cease to be Outstanding and
interest on them ceases to accrue. Notes may also cease to 



<PAGE>   28
                                      -20-


be Outstanding to the extent expressly provided in Article Four.

         "Permitted Affiliate Agreement" means each of the Series A Purchase
Agreement, the Series B Purchase Agreement, the Series C Purchase Agreement and
the Stockholders Agreement, each as in effect on the Issue Date.

         "Permitted Credit Facility" means any senior commercial term loan
and/or revolving credit facility (including any letter of credit subfacility)
entered into principally with commercial banks and/or other financial
institutions typically party to commercial loan agreements.

         "Permitted Equipment Financing" means any credit facility or other
financing arrangement (including in the form of Capitalized Lease Obligations
and guarantees of Indebtedness of ISPs) entered into with any vendor or supplier
(or any financial institution acting on behalf of or for the purpose of directly
financing purchases from such vendor or supplier) to the extent the Indebtedness
thereunder is incurred for the purpose of financing the cost (including the cost
of design, development, site acquisition, construction, integration, manufacture
or acquisition) of real or personal property (tangible or intangible) used, or
to be used, in an Internet Service Business.

         "Permitted Indebtedness" means the following Indebtedness (each of
which shall be given independent effect):

     (a) Indebtedness under the Notes and this Indenture;

     (b) Indebtedness of the Company and/or any Restricted Subsidiary
outstanding on the Issue Date, including, without limitation, the 1997 Notes;

     (c) (i) Indebtedness of any Restricted Subsidiary owed to and held by the 
Company or a Restricted Subsidiary and (ii) Indebtedness of the Company, not
secured by any Lien, owed to and held by any Restricted Subsidiary; provided
that an incurrence of Indebtedness shall be deemed to have occurred upon (x) any
sale or other disposition (excluding assignments as security to financial
institutions) of any Indebtedness of the Company or a Restricted Subsidiary
referred to in this clause (c) to a person (other than the Company or a
Restricted Subsidiary) or (y) any sale or other disposition of Capital Stock of
a Restricted Subsidiary, or Designation of a Restricted Subsidiary, which holds
Indebtedness of the Company or another Restricted Subsidiary 


<PAGE>   29
                                      -21-


such that such Restricted Subsidiary, in any such case, ceases to be a
Restricted Subsidiary;

     (d) Interest Rate Obligations of the Company and/or any Restricted 
Subsidiary relating to Indebtedness of the Company and/or such Restricted
Subsidiary, as the case may be (which Indebtedness (x) bears interest at
fluctuating interest rates and (y) is otherwise permitted to be incurred under
Section 10.11 hereof), but only to the extent that the notional principal amount
of such Interest Rate Obligations does not exceed the principal amount of the
Indebtedness (and/or Indebtedness subject to commitments) to which such Interest
Rate Obligations relate;

     (e) Indebtedness of the Company and/or any Restricted Subsidiary in respect
of performance bonds of the Company or any Restricted Subsidiary or surety bonds
provided by the Company or any Restricted Subsidiary incurred in the ordinary
course of business;

     (f) Indebtedness of the Company and/or any Restricted Subsidiary to the
extent it represents a replacement, renewal, refinancing or extension (a
"Refinancing") of outstanding Indebtedness of the Company and/or of any
Restricted Subsidiary incurred or outstanding pursuant to clause (a), (b), (g),
(h) or (i) of this definition or the proviso of Section 10.11 hereof; provided
that (1) Indebtedness of the Company may not be Refinanced to such extent under
this clause (f) with Indebtedness of any Restricted Subsidiary and (2) any such
Refinancing shall only be permitted under this clause (f) to the extent that (x)
it does not result in a lower Average Life to Stated Maturity of such
Indebtedness as compared with the Indebtedness being Refinanced and (y) it does
not exceed the sum of the principal amount (or, if such Indebtedness provides
for a lesser amount to be due and payable upon a declaration of acceleration
thereof, an amount no greater than such lesser amount) of the Indebtedness being
Refinanced plus the amount of accrued interest thereon and the amount of any
reasonably determined prepayment premium necessary to accomplish such
Refinancing and such reasonable fees and expenses incurred in connection
therewith;

     (g) Indebtedness of the Company such that, after giving effect to the
incurrence thereof, the total aggregate principal amount of Indebtedness
incurred under this clause (g) and any Refinancings thereof otherwise incurred
in compliance with this Indenture would not exceed 200% of Total Incremental
Equity;




<PAGE>   30
                                      -22-


     (h) Indebtedness of the Company and/or any Restricted Subsidiary incurred
under any Permitted Credit Facility and/or Indebtedness of the Company
represented by Debt Securities of the Company, and any Refinancings of the
foregoing otherwise incurred in compliance with this Indenture, in an aggregate
principal amount not to exceed $140.0 million at any time outstanding;

     (i) Indebtedness of the Company and/or any Restricted Subsidiary incurred 
under any Permitted Equipment Financing in an aggregate principal amount not to
exceed the Fair Market Value of the assets acquired with the proceeds thereof;

     (j) Indebtedness of the Company and/or any Restricted Subsidiary incurred 
as a result of any Rollup of any ISP, and any Refinancings thereof otherwise
incurred in compliance with this Indenture, provided the aggregate principal
amount of all such Indebtedness does not exceed $30.0 million at any time
outstanding;

     (k) Indebtedness of the Company representing the deferred purchase price 
(whether or not subject to a contingency) of an acquisition of, or an Investment
in, a New ISP in an aggregate principal amount not to exceed $30.0 million at
any time outstanding; and

     (l) in addition to the items referred to in clauses (a) through (j) above,
Indebtedness of the Company and/or the Restricted Subsidiaries having an
aggregate principal amount not to exceed $40.0 million at any time outstanding.

         "Permitted Investments" means (a) Cash Equivalents; (b) Investments in
prepaid expenses, negotiable instruments held for collection and lease, utility
and workers' compensation, performance and other similar deposits; (c) Interest
Rate Obligations incurred in compliance with Section 10.11 hereof; and (d) the
extension by the Company and the Restricted Subsidiaries of (i) trade credit to
Subsidiaries of the Company and the ISPs, represented by accounts receivable,
extended on usual and customary terms in the ordinary course of business or (ii)
guarantees of commitments for the purchase of goods or services by any ISP
incurred in the ordinary course of business so long as such guarantees to the
extent constituting Indebtedness are permitted to be incurred under Section
10.11 hereof.

         "Permitted Liens" means (a) Liens on property of a person existing at 
the time such person is merged into or consolidated with the Company or any
Restricted Subsidiary or 



<PAGE>   31
                                      -23-


becomes a Restricted Subsidiary; provided that such Liens were in existence
prior to the contemplation of such merger, consolidation or acquisition and do
not secure any property or assets of the Company or any Restricted Subsidiary
other than the property or assets subject to the Liens prior to such merger or
consolidation or acquisition; (b) Liens imposed by law, such as carriers',
warehousemen's and mechanics' Liens and other similar Liens arising in the
ordinary course of business that secure payment of obligations not more than 60
days past due or that are being contested in good faith and by appropriate
proceedings; (c) Liens existing on the Issue Date; (d) Liens for taxes,
assessments or governmental charges or claims that are not yet delinquent or
that are being contested in good faith by appropriate proceedings promptly
instituted and diligently conducted; provided that any reserve or other
appropriate provision as shall be required in conformity with GAAP shall have
been made therefor; (e) easements, rights of way, restrictions and other similar
easements, licenses, restrictions on the use of properties, or minor
imperfections of title that, in the aggregate, are not material in amount and do
not in any case materially detract from the properties subject thereto or
interfere with the ordinary conduct of the business of the Company or the
Restricted Subsidiaries; (f) Liens to secure the performance of statutory
obligations, surety or appeal bonds, performance bonds or other obligations of a
like nature incurred in the ordinary course of business; (g) Liens securing any
Permitted Credit Facility or Permitted Equipment Financing; (h) Liens to secure
Indebtedness incurred in compliance with clause (k) of the definition of
"Permitted Indebtedness" to the extent relating to the asset subject of the
particular Asset Acquisition or Investment; (i) Liens to secure any Refinancing
of any Indebtedness secured by Liens referred to in the foregoing clauses (a) or
(c), but only to the extent that such Liens do not extend to any other property
or assets and the principal amount of the Indebtedness secured by such Liens is
not increased; (j) Liens to secure the Notes; and (k) Liens on real property
incurred in connection with the financing of the purchase of such real property
(or incurred within 60 days of purchase) by the Company or any Restricted
Subsidiary.

         "person" means any individual, corporation, limited liability company,
partnership, joint venture, association, joint-stock company, trust,
unincorporated organization or government or any agency or political subdivision
thereof.

         "Predecessor Note" means, with respect to any particular Note, every
previous Note evidencing all or a portion of the same debt as that evidenced by
such particular Note; 



<PAGE>   32
                                      -24-


and, for the purposes of this definition, any Note authenticated and delivered
under Section 3.06 hereof in exchange for a mutilated Note or in lieu of a lost,
destroyed or stolen Note shall be deemed to evidence the same debt as the
mutilated, lost, destroyed or stolen Note.

         "Preferred Stock" means, with respect to any person, any and all
shares, interests, participations or other equivalents (however designated) of
such person's preferred or preference stock whether now outstanding, or issued
after the Issue Date, and including, without limitation, all classes and series
of preferred or preference stock of such person.

         "Private Exchange Notes" shall have the meaning specified in the
Registration Rights Agreement.

         "Private Placement Legend" shall mean the first paragraph of the legend
initially set forth in the Notes in the form set forth on Exhibit A-1.

         "Public Capital Stock" means any class of Capital Stock which is traded
on the New York Stock Exchange, the American Stock Exchange or the Nasdaq
National Market.

         "Public Equity Offering" means an underwritten public offering of
Common Stock (other than Disqualified Stock) made pursuant to a registration
statement filed with the Commission under the Securities Act.

         "Qualified Institutional Buyer" or "QIB" shall have the meaning
specified in Rule 144A under the Securities Act.

         "Qualifying Preferred Stock" means preferred stock of an ISP (i) having
a liquidation and dividend preference at least equal to the amount of the
Investment made by the Company or a Restricted Subsidiary in such ISP, (ii)
that, in the case of ISPs not constituting Restricted Subsidiaries, is
redeemable at the option of the holder on a basis consistent with past practice,
and (iii) that is convertible into shares of Common Stock of such ISP at the
option of the holder.

         "Redemption Date" means, with respect to any Note to be redeemed, the
date fixed by the Company for such redemption pursuant to this Indenture and the
Notes.

         "Redemption Price" means, with respect to any Note to be redeemed, the
price fixed for such redemption pursuant to the terms of this Indenture and the
Notes.




<PAGE>   33
                                      -25-


         "Refinancing" has the meaning set forth in clause (f) of the definition
of "Permitted Indebtedness."

         "Registrable Securities" shall have the meaning specified in the
Registration Rights Agreement.

         "Registration Rights Agreement" means the Registration Rights Agreement
dated as of March 25, 1998 by and among the Company and the Initial Purchasers,
as the same may be amended, supplemented or otherwise modified from time to time
in accordance with the terms thereof.

         "Regular Record Date" means the Regular Record Date specified in the
Notes.

         "Regulation S" means Regulation S under the Securities Act.

         "Regulation S Global Note" means a permanent global note in registered
form representing the aggregate principal amount of Notes sold in reliance on
Regulation S under the Securities Act.

         "Responsible Officer" means, with respect to the Trustee, the chairman
or vice chairman of the board of directors, the chairman or vice chairman of the
executive committee of the board of directors, the president, any vice
president, the secretary, any assistant secretary, the treasurer, any assistant
treasurer, the cashier, any assistant cashier, any trust officer or assistant
trust officer, the controller and any assistant controller or any other officer
of the Trustee customarily performing functions similar to those performed by
any of the above designated officers and also means, with respect to a
particular corporate trust matter, any other officer of the Trustee to whom any
corporate trust matter is referred because of his or her knowledge of and
familiarity with the particular subject.

         "Restricted Note" means a Note that constitutes a "restricted security"
within the meaning of Rule 144(a)(3) under the Securities Act; provided,
however, that the Trustee shall be entitled to request and conclusively rely on
an Opinion of Counsel with respect to whether any Note constitutes a Restricted
Note.

         "Restricted Payment" means any of the following: (i) the declaration or
payment of any dividend or any other distribution on Capital Stock of the
Company or any payment made to 



<PAGE>   34
                                      -26-


the direct or indirect holders (in their capacities as such) of Capital Stock of
the Company (other than dividends or distributions payable solely in Capital
Stock (other than Disqualified Stock) of the Company or in options, warrants or
other rights to purchase Capital Stock (other than Disqualified Stock) of the
Company; (ii) the purchase, redemption or other acquisition or retirement for
value of any Capital Stock of the Company (other than such Capital Stock owned
by the Company or a Wholly Owned Restricted Subsidiary); (iii) the purchase,
redemption, defeasance or other acquisition or retirement for value prior to any
scheduled repayment, sinking fund or maturity of any Subordinated Indebtedness
(other than any Subordinated Indebtedness held by a Wholly Owned Restricted
Subsidiary); (iv) the making of any payment (whether of dividends or in respect
of liquidation preference) in respect of the Series A Preferred Stock, the
Series B Preferred Stock, the Series C Preferred Stock or the Series D Preferred
Stock; or (v) the making by the Company or any Restricted Subsidiary of any
Investment (other than a Permitted Investment) in any person (other than an
Investment by a Restricted Subsidiary in the Company or an Investment by the
Company or a Restricted Subsidiary in (a) a Wholly Owned Restricted Subsidiary
engaged principally in an Internet Service Business; (b) a New ISP that is a
Restricted Subsidiary; (c) a person (other than an existing ISP) engaged
principally in an Internet Service Business that becomes a Wholly Owned
Restricted Subsidiary as a result of such Investment; (d) a New ISP that becomes
a Restricted Subsidiary as a result of such Investment; or (e) a Restricted
Subsidiary (other than an Existing ISP) or a person (other than an Existing ISP)
that becomes a Restricted Subsidiary as a result of such Investment, provided
that, in either case, such Restricted Subsidiary would, but for failing to meet
the requirements of clauses (c) and (d) of the definition of "ISP," be a New
ISP).

         "Restricted Subsidiary" means any Subsidiary of the Company that has
not been designated by the Board, by a Board Resolution delivered to the
Trustee, as an Unrestricted Subsidiary pursuant to and in compliance with
Section 10.21 hereof. Any such designation may be revoked by a Board Resolution
delivered to the Trustee, subject to the provisions of such covenant.

         "Restricted Subsidiary Indebtedness" means Indebtedness of any
Restricted Subsidiary (i) which is not subordinated to any other Indebtedness of
such Restricted Subsidiary and (ii) in respect of which the Company is not also
obligated (by means of a guarantee or otherwise) other than, in the case of 


<PAGE>   35
                                      -27-


this clause (ii), Indebtedness under any Permitted Credit Facilities.

         "Revocation" has the meaning set forth under Section 10.21 hereof.

         "Rollup" means (i) an Investment in an Existing ISP or transaction or
series of related transactions as a result of which such Existing ISP becomes a
Wholly Owned Restricted Subsidiary or (ii) an Investment in a New ISP or
transaction or series of related transactions as a result of which such New ISP
becomes a Restricted Subsidiary or (iii) a merger or consolidation of any ISP
with the Company.

         "Rule 144A" means Rule 144A under the Securities Act.

         "S&P" means Standard & Poor's Corporation.

         "SEC" means the Securities and Exchange Commission, as from time to
time constituted, or if at any time after the execution of this Indenture such
Commission is not existing and performing the applicable duties now assigned to
it, then the body or bodies performing such duties at such time.

         "Securities Act" means the Securities Act of 1933, as amended, and the
rules and regulations promulgated by the SEC thereunder.

         "Series A Preferred Stock" has the meaning provided in the Offering
Memorandum.

         "Series A Purchase Agreement" has the meaning provided in the Offering
Memorandum.

         "Series B Preferred Stock" has the meaning provided in the Offering
Memorandum.

         "Series B Purchase Agreement" has the meaning provided in the Offering
Memorandum.

         "Series C Preferred Stock" has the meaning provided in the Offering
Memorandum.

         "Series C Purchase Agreement" has the meaning provided in the Offering
Memorandum.

         "Series D Preferred Stock" has the meaning provided in the Offering
Memorandum.


<PAGE>   36
                                      -28-


         "Special Record Date" means, with respect to the payment of any
Defaulted Interest, a date fixed by the Trustee pursuant to Section 3.07 hereof.

         "Stated Maturity" means, with respect to any Note or any installment of
interest thereon, the dates specified in such Note as the fixed date on which
the principal of such Note or such installment of interest is due and payable
and, when used with respect to any other Indebtedness, means the date specified
in the instrument governing such Indebtedness as the fixed date on which the
principal of such Indebtedness, or any installment of interest, is due and
payable.

         "Stockholders Agreement" has the meaning provided in the Offering
Memorandum.

         "Strategic Equity Investor" means any person engaged principally in one
or more communications businesses with a Market Capitalization or Consolidated
Net Worth of at least $1.0 billion.

         "Subordinated Indebtedness" means any Indebtedness of the Company or
any Guarantor which is expressly subordinated in right of payment to any other
Indebtedness of the Company or such Guarantor.

         "Subsidiary" means, with respect to any person, (i) any corporation of
which the outstanding Capital Stock having at least a majority of the votes
entitled to be cast in the election of directors shall at the time be owned,
directly or indirectly, by such person, or (ii) any other person of which at
least a majority of voting interest is at the time, directly or indirectly,
owned by such person.

         "Total Consolidated Indebtedness" means, at any date of determination,
an amount equal to the aggregate amount of all Indebtedness of the Company and
the Restricted Subsidiaries outstanding as of the date of determination.

         "Total Incremental Equity" means, at any time of determination, the sum
of, without duplication, (i) the aggregate cash proceeds received prior to June
24, 2000 by the Company from capital contributions in respect of existing
Capital Stock (other than Disqualified Capital Stock) or the issuance or sale of
Capital Stock (other than Disqualified Stock but including Capital Stock issued
upon the conversion of convertible Indebtedness or from the exercise of options,
warrants or rights to purchase Capital Stock (other than Disqualified Stock))
subsequent 


<PAGE>   37
                                      -29-


to the Issue Date, other than to a Subsidiary of the Company, plus (ii) the Fair
Market Value (determined at the time of issuance) of any Capital Stock (other
than Disqualified Stock) of the Company issued prior to June 24, 2000 as
consideration for the acquisition of Capital Stock of an ISP (other than the
acquisition of Capital Stock of an Existing ISP), plus (iii) the Fair Market
Value (determined at the time of issuance) of any Capital Stock (other than
Disqualified Stock) of the Company issued prior to June 24, 2000 as
consideration for the acquisition of Capital Stock of an Existing ISP in a
transaction as a result of which the Existing ISP becomes a Wholly Owned
Restricted Subsidiary, plus (iv) the aggregate cash proceeds received by the
Company or any Restricted Subsidiary from the sale, disposition or repayment (in
whole or in part) of any Investment that is made after the Issue Date and that
constitutes a Restricted Payment that has been deducted from Total Incremental
Equity pursuant to clause (v) below in an amount equal to the lesser of (a) the
return of capital with respect to the applicable portion of such Investment and
(b) the cost of the applicable portion of such Investment, in either case, less
the cost of the disposition of such Investment, minus (v) the aggregate amount
of all Restricted Payments declared or made on and after the Issue Date (other
than (1) a Restricted Payment constituting an Investment in an ISP (other than
the acquisition of Capital Stock of an Existing ISP in a transaction as a result
of which the Existing ISP becomes a Wholly Owned Restricted Subsidiary) and (2)
a Restricted Payment made pursuant to clauses (iii), (viii) or (ix) (solely, in
the case of clause (ix), to the extent the Investment is made in a Restricted
Subsidiary) of the third paragraph of Section 10.13 hereof).

         "Trust Indenture Act" or "TIA" means the Trust Indenture Act of 1939,
as amended.

         "Trustee" means the person named as the "Trustee" in the first
paragraph of this Indenture, until a successor Trustee shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Trustee" shall mean such successor Trustee.

         "Unrestricted Notes" means one or more Notes that do not and are not
required to bear the Private Placement Legend in the form set forth in Exhibit
A, including, without limitation, the Exchange Notes.

         "Unrestricted Subsidiary" means any Subsidiary of the Company
designated as such pursuant to and in compliance with 



<PAGE>   38
                                      -30-


Section 10.21 hereof. Any such designation may be revoked by a Board Resolution
delivered to the Trustee, subject to the provisions of such covenant.

         "Voting Stock" means, with respect to any person, the Capital Stock of
any class or kind ordinarily having the power to vote for the election of
directors or other members of the governing body of such person.

         "Wholly Owned Restricted Subsidiary" means any Restricted Subsidiary of
which 99% or more of the outstanding Capital Stock is owned by the Company or
another Wholly Owned Restricted Subsidiary; provided NorthWestNet shall be
deemed a Wholly Owned Restricted Subsidiary notwithstanding its existing stock
option plan and any stock options issued thereunder. For the purposes of this
definition, any directors' qualifying shares or investments by foreign nationals
mandated by applicable law shall be disregarded in determining the ownership of
a Restricted Subsidiary.

         "WorldCom" means WorldCom, Inc. (and its successors by merger or
consolidation) and its controlled Affiliates.

         Section 1.02. Other Definitions.

<TABLE>
<CAPTION>
                                                                 Defined in
         Term                                                     Section
         ----                                                     -------
<S>                                                               <C> 
         "Act"                                                      1.05
         "Affiliate Transaction"                                   10.14
         "Agent Member"                                             3.16
         "Asset Sale Offer"                                        10.15
         "Asset Sale Offer Purchase Date"                          10.15
         "assumed liabilities"                                     10.15
         "Change of Control Date"                                  10.10
         "Change of Control Offer"                                 10.10
         "Change of Control Payment Date"                          10.10
         "covenant defeasance"                                      4.03
         "Defaulted Interest"                                       3.07
         "defeasance"                                               4.02
         "Defeased Notes"                                           4.01
         "Designation"                                             10.21
         "Designation Amount"                                      10.21
         "Event of Default"                                         5.01
         "Excess Proceeds"                                         10.15
         "Guarantee"                                               10.18
         "Guarantor"                                               10.18
         "incur"                                                   10.11
</TABLE>



<PAGE>   39
                                      -31-


<TABLE>
<S>                                                                 <C> 
         "insolvent person"                                         4.04
         "Note Register"                                            3.05
         "Offer Excess Proceeds"                                   10.15
         "Paying Agent" or "Agent"                                  3.02
         "Physical Notes"                                           3.03
         "Registrar"                                                3.02
         "Replacement Assets"                                      10.15
         "Restricted Period"                                        3.17
         "Revocation"                                              10.21
         "surviving entity"                                         8.01
</TABLE>

         Section 1.03. Rules of Construction.

         For all purposes of this Indenture, except as otherwise expressly
provided or unless the context otherwise requires:

         (a) the terms defined in this Article have the meanings assigned to
them in this Article, and include the plural as well as the singular;

         (b) all other terms used herein which are defined in the Trust
Indenture Act, either directly or by reference therein, have the meanings
assigned to them therein;

         (c) all accounting terms not otherwise defined herein have the meanings
assigned to them in accordance with GAAP;

         (d) the words "herein" "hereof" and "hereunder" and other words of
similar import refer to this Indenture as a whole and not to any particular
Article, Section or other subdivision;

         (e) all references to "$" or "dollars" refer to the lawful currency of
the United States of America; and

         (f) the words "include", "included" and "including" as used herein are
deemed in each case to be followed by the phrase "without limitation".

         Section 1.04. Form of Documents Delivered to Trustee.

         In any case where several matters are required to be certified by, or
covered by an opinion of, any specified person, it is not necessary that all
such matters be certified by, or covered by the opinion of, only one such
person, or that 



<PAGE>   40
                                      -32-


they be so certified or covered by only one document, but one such person may
certify or give an opinion with respect to some matters and one or more other
persons as to other matters, and any such person may certify or give an opinion
as to such matters in one or several documents.

         Any certificate or opinion of an officer of the Company may be based,
insofar as it relates to legal matters, upon a certificate or opinion of, or
representations by, counsel, unless such officer knows, or in the exercise of
reasonable care should know, that the certificate or opinion or representations
with respect to the matters upon which his certificate or opinion is based are
erroneous. Any such certificate or opinion may be based, insofar as it relates
to factual matters, upon a certificate or opinion of, or representations by, an
officer or officers of the Company stating that the information with respect to
such factual matters is in the possession of the Company, unless such counsel
knows, or in the exercise of reasonable care should know, that the certificate
or opinion or representations with respect to such matters are erroneous.

         Where any person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Indenture, they may, but need not, be consolidated, with
proper identification of each matter covered therein, and form one instrument.

         Section 1.05. Acts of Holders.

         (a) Any request, demand, authorization, direction, notice, consent,
waiver or other action provided by this Indenture to be given or taken by
Holders may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Holders in person or by an agent duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required, to the Company. Such
instrument or instruments (and the action embodied therein and evidenced
thereby) are herein sometimes referred to as the "Act" of the Holders signing
such instrument or instruments. Proof of execution (as provided below in
subsection (b) of this Section 1.05) of any such instrument or of a writing
appointing any such agent shall be sufficient for any purpose of this Indenture
and (subject to Section 6.01 hereof) conclusive in favor of the Trustee and the
Company, if made in the manner provided in this Section.



<PAGE>   41
                                      -33-


         (b) The fact and date of the execution by any person of any such
instrument or writing may be proved in any reasonable manner which the Trustee
deems sufficient.

         (c) The ownership of Notes shall be proved by the Note Register.

         (d) Any request, demand, authorization, direction, notice, consent,
waiver or other action by the Holder of any Note shall bind every future Holder
of the same Note or the Holder of every Note issued upon the transfer thereof or
in exchange therefor or in lieu thereof to the same extent as the original
Holder, in respect of anything done, suffered or omitted to be done by the
Trustee, any Paying Agent or the Company in reliance thereon, whether or not
notation of such action is made upon such Note.

         Section 1.06. Notices, etc., to the Trustee and the Company.

         Any request, demand, authorization, direction, notice, consent, waiver
or Act of Holders or other document provided or permitted by this Indenture to
be made upon, given or furnished to, or filed with:

         (a) the Trustee by any Holder or by the Company shall be sufficient for
every purpose hereunder if made, given, furnished or filed, in writing, to or
with the Trustee at the Corporate Trust Office, Attention: Corporate Trust
Department or at any other address previously furnished in writing to the
Holders and the Company by the Trustee; or

         (b) the Company by the Trustee or by any Holder shall be sufficient for
every purpose (except as otherwise expressly provided herein) hereunder if in
writing and mailed, first-class postage prepaid, to the Company addressed to it
at Verio Inc., 8005 South Chester Street, Suite 200, Englewood, Colorado 80112,
Attention: Chief Executive Officer, or at any other address previously furnished
in writing to the Trustee by the Company.

         Section 1.07. Notice to Holders; Waiver.

         Where this Indenture provides for notice to Holders of any event, such
notice shall be sufficiently given (unless otherwise expressly provided herein)
if in writing and mailed, first-class postage prepaid, to each Holder affected
by such event, at the address of such Holder as it appears in the Note 



<PAGE>   42
                                      -34-


Register, not later than the latest date, and not earlier than the earliest
date, prescribed for the giving of such notice. In any case where notice to
Holders is given by mail, neither the failure to mail such notice, nor any
defect in any notice so mailed, to any particular Holder shall affect the
sufficiency of such notice with respect to other Holders. Any notice when mailed
to a Holder in the aforesaid manner shall be conclusively deemed to have been
received by such Holder whether or not actually received by such Holder. Where
this Indenture provides for notice in any manner, such notice may be waived in
writing by the person entitled to receive such notice, either before or after
the event, and such waiver shall be the equivalent of such notice. Waivers of
notice by Holders shall be filed with the Trustee, but such filing shall not be
a condition precedent to the validity of any action taken in reliance upon such
waiver.

         In case by reason of the suspension of regular mail service or by
reason of any other cause, it shall be impracticable to mail notice of any event
as required by any provision of this Indenture, then any method of giving such
notice as shall be satisfactory to the Trustee shall be deemed to be a
sufficient giving of such notice.

         Section 1.08. Conflict with Trust Indenture Act.

         If any provision hereof limits, qualifies or conflicts with any
provision of the Trust Indenture Act or another provision which is required or
deemed to be included in this Indenture by any of the provisions of the Trust
Indenture Act, such provision or requirement of the Trust Indenture Act shall
control.

         If any provision of this Indenture modifies or excludes any provision
of the Trust Indenture Act that may be so modified or excluded, the latter
provision shall be deemed to apply to this Indenture as so modified or excluded,
as the case may be.

         Section 1.09. Effect of Headings and Table of Contents.

         The Article and Section headings herein and the Table of Contents are
for convenience only and shall not affect the construction hereof.


<PAGE>   43
                                      -35-


         Section 1.10. Successors and Assigns.

         All covenants and agreements in this Indenture by the Company shall
bind its successors and assigns, whether so expressed or not.

         Section 1.11. Separability Clause.

         In case any provision in this Indenture or in the Notes issued pursuant
hereto shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

         Section 1.12. Benefits of Indenture.

         Nothing in this Indenture or in the Notes issued pursuant hereto,
express or implied, shall give to any person (other than the parties hereto and
their successors hereunder, any Paying Agent and the Holders) any benefit or any
legal or equitable right, remedy or claim under this Indenture.

         Section 1.13. GOVERNING LAW.

         THIS INDENTURE, THE NOTES AND ANY GUARANTEE SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT GIVING
EFFECT TO PRINCIPLES OF CONFLICTS OF LAW.

         Section 1.14. No Recourse Against Others.

         A director, officer, employee or stockholder, as such, of the Company
shall not have any liability for any obligations of the Company under the Notes
or this Indenture or for any claim based on, in respect of or by reason of such
obligations or their creation.

         Section 1.15. Independence of Covenants.

         All covenants and agreements in this Indenture shall be given
independent effect so that if a particular action or condition is not permitted
by any of such covenants, the fact that it would be permitted by an exception
to, or be otherwise within the limitations of, another covenant shall not avoid
the occurrence of a Default if such action is taken or condition exists.


<PAGE>   44
                                      -36-


         Section 1.16. Exhibits.

         All exhibits attached hereto are by this reference made a part hereof
with the same effect as if herein set forth in full.

         Section 1.17. Counterparts.

         This Indenture may be executed in any number of counterparts and by
telecopier, each of which shall be an original; but such counterparts shall
together constitute but one and the same instrument.

         Section 1.18. Duplicate Originals.

         The parties may sign any number of copies of this Indenture. Each
signed copy shall be an original, but all of them together represent the same
agreement.

                                   ARTICLE TWO

                                   NOTE FORMS

         Section 2.01. Form and Dating.

         The Notes and the Trustee's certificate of authentication with respect
thereto shall be in substantially the forms set forth, or referenced, in Exhibit
A-1 and Exhibit A-2, respectively, annexed hereto, with such appropriate
insertions, omissions, substitutions and other variations as are required or
permitted by this Indenture and may have such letters, numbers or other marks of
identification and such legends or endorsements placed thereon as may be
required to comply with any applicable law or with the rules of the Depository,
any clearing agency or any securities exchange or as may, consistently herewith,
be determined by the officers executing such Notes, as evidenced by their
execution thereof.

         The definitive Notes shall be printed, typewritten, lithographed or
engraved or produced by any combination of these methods or may be produced in
any other manner permitted by the rules of any securities exchange on which the
Notes may be listed, all as determined by the officers executing such Notes, as
evidenced by their execution of such Notes.



<PAGE>   45
                                      -37-


         Each Note shall be dated the date of its issuance and shall show the
date of its authentication. The terms and provisions contained in the Notes
shall constitute, and are expressly made, a part of this Indenture.

                                  ARTICLE THREE

                                    THE NOTES

         Section 3.01. Title and Terms.

         The aggregate principal amount of Notes which may be authenticated and
delivered under this Indenture is limited to $175,000,000 in aggregate principal
amount of Notes, except for Notes authenticated and delivered upon registration
of transfer of, or in exchange for, or in lieu of, other Notes pursuant to
Section 3.03, 3.04, 3.05, 3.06, 9.06, 10.10 or 10.15 hereof.

         The final Stated Maturity of the Notes shall be April 1, 2005, and the
Notes shall bear interest at the rate of 10-3/8% per annum from the Issue Date
or from the most recent Interest Payment Date to which interest has been paid,
as the case may be, payable semi-annually thereafter on April 1 and October 1,
in each year, commencing on October 1, 1998, to the Holders of record at the
close of business on the March 15 and September 15, respectively, immediately
preceding such Interest Payment Dates, until the principal thereof is paid or
duly provided for. Interest on any overdue principal, interest (to the extent
lawful) or premium, if any, shall be payable on demand.

         At the election of the Company, the entire Indebtedness on the Notes or
certain of the Company's obligations and covenants and certain Events of Default
thereunder may be defeased as provided in Article Four.

         Section 3.02. Registrar and Paying Agent.

         The Company shall maintain an office or agency (which shall be located
in the Borough of Manhattan in The City of New York, State of New York) where
Notes may be presented for registration of transfer or for exchange (the
"Registrar"), an office or agency (which shall be located in the Borough of
Manhattan in The City of New York, State of New York) where Notes may be
presented for payment (the "Paying Agent" or "Agent") and an office or agency
where notices and demands to or upon the Company in respect of the Notes and
this Indenture may be 



<PAGE>   46
                                      -38-


served. The Registrar shall keep a register of the Notes and of their transfer
and exchange. The Company may have one or more co-registrars and one or more
additional paying agents. The term "Paying Agent" or "Agent" includes any
additional paying agent. The Company may act as its own Paying Agent, except for
the purposes of payments on account of principal on the Notes pursuant to
Sections 10.10 and 10.15 hereof.

         The Company shall enter into an appropriate agency agreement with any
Agent not a party to this Indenture, which shall incorporate the provisions of
the Trust Indenture Act. The agreement shall implement the provisions of this
Indenture that relate to such Agent. The Company shall notify the Trustee of the
name and address of any such Agent. If the Company fails to maintain a Registrar
or Paying Agent, or fails to give the foregoing notice, the Trustee shall act as
such and shall be entitled to appropriate compensation in accordance with
Section 6.07 hereof.

         The Company initially appoints the Trustee as the Registrar and Paying
Agent and agent for service of notices and demands in connection with the Notes.

         Section 3.03. Execution and Authentication.

         The Initial Notes and the Trustee's certificate of authentication shall
be substantially in the form of Exhibit A-1 hereto. The Exchange Notes and the
Trustee's certificate of authentication relating thereto shall be substantially
in the form of Exhibit A-2 hereto. The Notes may have notations, legends or
endorsements required by law, stock exchange rule or usage. The Company shall
approve the form of the Notes and any notation, legend or endorsement thereon.
Each Note shall be dated the date of issuance and shall show the date of its
authentication.

         The terms and provisions contained in the Notes annexed hereto as
Exhibits A-1 and A-2 shall constitute, and are hereby expressly made, a part of
this Indenture and, to the extent applicable, the Company and the Trustee, by
their execution and delivery of this Indenture, expressly agree to such terms
and provisions and to be bound thereby.

         Notes offered and sold in reliance on Rule 144A and Notes offered and
sold in reliance on Regulation S shall be issued initially in the form of one or
more Global Notes, substantially in the form set forth in Exhibit A-1, deposited
with the Trustee, as custodian for the Depository, duly executed by 


<PAGE>   47
                                    -39-

the Company and authenticated by the Trustee as hereinafter provided and shall
bear the legend set forth in Exhibit B.  The aggregate principal amount of the
Global Notes may from time to time be increased or decreased by adjustments
made on the records of the Trustee, as custodian for the Depository, as
hereinafter provided.

         Notes (i) offered and sold to institutional "accredited investors" (as
defined in Rule 501(a)(1), (2), (3) or (7) under the Securities Act) and (ii)
issued in exchange for interests in a Global Note pursuant to Section 3.17
hereof may be issued in the form of permanent certificated Notes in registered
form in substantially the form set forth in Exhibit A-1 (the "Physical Notes").


         All Notes offered and sold in reliance on Regulation S shall remain in
the form of a Global Note until the consummation of the Exchange Offer pursuant
to the Registration Rights Agreement; provided, however, that all of the time
periods specified in the Registration Rights Agreement to be complied with by
the Company have been so complied with.

         Two Officers, or an Officer and an Assistant Secretary, shall sign, or
one Officer shall sign, and one Officer or an Assistant Secretary (each of whom
shall, in each case, have been duly authorized by all requisite corporate
actions) shall attest to, the Notes for the Company by manual or facsimile
signature.

         If an Officer or Assistant Secretary whose signature is on a Note was
an Officer or Assistant Secretary at the time of such execution but no longer
holds that office or position at the time the Trustee authenticates the Note,
the Note shall nevertheless be valid.

         The Trustee shall authenticate (i) Initial Notes for original issue in
an aggregate principal amount not to exceed $175,000,000, (ii) Private Exchange
Notes from time to time only in exchange for a like principal amount of Initial
Notes and (iii) Unrestricted Notes from time to time only in exchange for (A) a
like principal amount of Initial Notes or (B) a like principal amount of
Private Exchange Notes, in each case upon a written order of the Company in the
form of an Officers' Certificate of the Company.  Each such written order shall
specify the amount of Notes to be authenticated and the date on which the Notes
are to be authenticated, whether the Notes are to be Initial Notes, Private
Exchange Notes or Unrestricted Notes and whether (subject to this Section 3.03)
the Notes are to be
<PAGE>   48
                                      -40-

issued as Physical Notes or Global Notes and such other information as the
Trustee may reasonably request.  The aggregate principal amount of Notes
Outstanding at any time may not exceed $175,000,000, except as provided in
Section 3.06 hereof.

         Notwithstanding the foregoing, all Notes issued under this Indenture
shall vote and consent together on all matters (as to which any of such Notes
may vote or consent) as one class and no series of Notes will have the right to
vote or consent as a separate class on any matter.

         The Trustee may appoint an authenticating agent reasonably acceptable
to the Company to authenticate Notes.  Unless otherwise provided in the
appointment, an authenticating agent may authenticate Notes whenever the
Trustee may do so.  Each reference in this Indenture to authentication by the
Trustee includes authentication by such agent.  An authenticating agent has the
same rights as an Agent to deal with the Company and Affiliates of the Company.

         The Notes shall be issuable in fully registered form only, without
coupons, in denominations of $1,000 and any integral multiple thereof.

         Section 3.04.    Temporary Notes.

         Until definitive Notes are prepared and ready for delivery, the
Company may execute and upon a Company Order the Trustee shall authenticate and
deliver temporary Notes.  Temporary Notes shall be substantially in the form of
definitive Notes, in any authorized denominations, but may have variations that
the Company reasonably considers appropriate for temporary Notes as
conclusively evidenced by the Company's execution of such temporary Notes.

         If temporary Notes are issued, the Company will cause definitive Notes
to be prepared without unreasonable delay but in no event later than the date
that the Exchange Offer is consummated.  After the preparation of definitive
Notes, the temporary Notes shall be exchangeable for definitive Notes upon
surrender of the temporary Notes at the office or agency of the Company
designated for such purpose pursuant to Section 10.02 hereof, without charge to
the Holder.  Upon surrender for cancellation of any one or more temporary
Notes, the Company shall execute and the Trustee shall authenticate and deliver
in exchange therefor a like principal amount of definitive Notes of like tenor
and of authorized denominations.  Until so exchanged
<PAGE>   49
                                      -41-

the temporary Notes shall in all respects be entitled to the same benefits
under this Indenture as definitive Notes.

         Section 3.05.    Transfer and Exchange.

         The Company shall cause to be kept at the Corporate Trust Office of
the Trustee a register (the register maintained in such office and in any other
office or agency designated pursuant to Section 10.02 hereof being sometimes
referred to herein as the "Note Register") in which, subject to such reasonable
regulations as the Registrar may prescribe, the Company shall provide for the
registration of Notes and of transfers and exchanges of Notes.  The Trustee is
hereby initially appointed Registrar for the purpose of registering Notes and
transfers of Notes as herein provided.

         When Notes are presented to the Registrar or a co-Registrar with a
request from the Holder of such Notes to register the transfer or exchange for
an equal principal amount of Notes of other authorized denominations, the
Registrar shall register the transfer or make the exchange as requested;
provided, however, that every Note presented or surrendered for registration of
transfer or exchange shall be duly endorsed or be accompanied by a written
instrument of transfer or exchange in form satisfactory to the Company and the
Registrar, duly executed by the Holder thereof or his attorney duly authorized
in writing.  Whenever any Notes are so presented for exchange, the Company
shall execute, and the Trustee shall authenticate and deliver, the Notes which
the Holder making the exchange is entitled to receive.  No service charge shall
be made to the Noteholder for any registration of transfer or exchange.  The
Company may require from the Noteholder payment of a sum sufficient to cover
any transfer taxes or other governmental charge that may be imposed in relation
to a transfer or exchange, but this provision shall not apply to any exchange
pursuant to Section 10.10, 10.15 or 9.06 hereof (in which events the Company
will be responsible for the payment of all such taxes which arise solely as a
result of the transfer or exchange and do not depend on the tax status of the
Holder).  The Trustee shall not be required to exchange or register the
transfer of any Note for a period of 15 days immediately preceding the first
mailing of notice of redemption of Notes to be redeemed or of any Note
selected, called or being called for redemption except, in the case of any Note
where public notice has been given that such Note is to be redeemed in part,
the portion thereof not to be redeemed.
<PAGE>   50
                                      -42-

         All Notes issued upon any registration of transfer or exchange of
Notes shall be the valid obligations of the Company, evidencing the same
Indebtedness, and entitled to the same benefits under this Indenture, as the
Notes surrendered upon such registration of transfer or exchange.

         Any Holder of a beneficial interest in a Global Note shall, by
acceptance of such Global Note, agree that transfers of beneficial interests in
such Global Notes may be effected only through a book-entry system maintained
by the Holder of such Global Note (or its agent), and that ownership of a
beneficial interest in the Note shall be required to be reflected in a book-
entry system.

         Section 3.06.    Mutilated, Destroyed, Lost and Stolen Notes.

         If a mutilated Note is surrendered to the Trustee or if the Holder of
a Note of any series claims that the Note has been lost, destroyed or
wrongfully taken, the Company shall execute and upon a Company Order, the
Trustee shall authenticate and deliver a replacement Note of like tenor and
principal amount, bearing a number not contemporaneously outstanding if the
Holder of such Note furnishes to the Company and to the Trustee evidence
reasonably acceptable to them of the ownership and the destruction, loss or
theft of such Note and an indemnity bond shall be posted by such Holder,
sufficient in the judgment of the Company or the Trustee, as the case may be,
to protect the Company, the Trustee or any Agent from any loss that any of them
may suffer if such Note is replaced.  The Company may charge such Holder for
the Company's expenses in replacing such Note (including (i) expenses of the
Trustee charged to the Company and (ii) any tax or other governmental charge
that may be imposed) and the Trustee may charge the Company for the Trustee's
expenses in replacing such Note.

         Every replacement Note issued pursuant to this Section in lieu of any
destroyed, lost or stolen Note shall constitute an original additional
contractual obligation of the Company, whether or not the destroyed, lost or
stolen Note shall be at any time enforceable by anyone, and shall be entitled
to all benefits of this Indenture equally and proportionately with any and all
other Notes duly issued hereunder.

         The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the
replacement or payment of mutilated, destroyed, lost or stolen Notes.
<PAGE>   51
                                      -43-

         Section 3.07.    Payment of Interest; Interest Rights Preserved.

         Interest on any Note which is payable, and is punctually paid or duly
provided for, on any Interest Payment Date shall be paid to the person in whose
name that Note (or one or more Predecessor Notes) is registered at the close of
business on the Regular Record Date for such interest.

         Any interest on any Note which is payable, but is not punctually paid
or duly provided for, on any Interest Payment Date and interest on such
defaulted interest at the then  applicable interest rate borne by the Notes, to
the extent lawful (such defaulted interest and interest thereon herein
collectively called "Defaulted Interest") shall forthwith cease to be payable
to the Holder on the Regular Record Date; and such Defaulted Interest may be
paid by the Company, at its election in each case, as provided in subsection
(a) or (b) below:

         (a)  The Company may elect to make payment of any Defaulted Interest
to the persons in whose names the Notes (or their respective Predecessor Notes)
are registered at the close of business on a Special Record Date for the
payment of such Defaulted Interest, which shall be fixed in the following
manner.  The Company shall notify the Trustee in writing of the amount of
Defaulted Interest proposed to be paid on each Note and the date of the
proposed payment, and at the same time the Company shall deposit with the
Trustee an amount of money equal to the aggregate amount proposed to be paid in
respect of such Defaulted Interest or shall make arrangements satisfactory to
the Trustee for such deposit prior to the date of the proposed payment, such
money when deposited to be held in trust for the benefit of the persons
entitled to such Defaulted Interest as provided in this subsection (a).
Thereupon the Trustee shall fix a Special Record Date for the payment of such
Defaulted Interest which shall be not more than 15 days and not less than 10
days prior to the date of the proposed payment and not less than 10 days after
the receipt by the Trustee of the notice of the proposed payment.  The Trustee
shall promptly notify the Company in writing of such Special Record Date.  In
the name and at the expense of the Company, the Trustee shall cause notice of
the proposed payment of such Defaulted Interest and the Special Record Date
therefor to be mailed, first-class postage prepaid, to each Holder at its
address as it appears in the Note Register, not less than 10 days prior to such
Special Record Date.  Notice of the proposed payment of such Defaulted Interest
and the Special Record Date therefor having been so mailed, such Defaulted
Interest shall be paid to the persons in
<PAGE>   52
                                      -44-

whose names the Notes (or their respective Predecessor Notes) are registered on
such Special Record Date and shall no longer be payable pursuant to the
following subsection (b).

         (b)  The Company may make payment of any Defaulted Interest in any
other lawful manner not inconsistent with  the requirements of any securities
exchange on which the Notes may be listed, and upon such notice as may be
required by such exchange, if, after written notice given by the Company to the
Trustee of the proposed payment pursuant to this subsection (b), such payment
shall be deemed practicable by the Trustee.

         Subject to the foregoing provisions of this Section, each Note
delivered under this Indenture upon registration of transfer of or in exchange
for or in lieu of any other Note shall carry the rights to interest accrued and
unpaid, and to accrue, which were carried by such other Note.

         Section 3.08.    Persons Deemed Owners.

         Prior to and at the time of due presentment for registration of
transfer, the Company, the Trustee and any agent of the Company or the Trustee
may treat the person in whose name any Note is registered in the Note Register
as the owner of such Note for the purpose of receiving payment of principal of,
premium, if any, and (subject to Section 3.07 hereof) interest on such Note and
for all other purposes whatsoever, whether or not such Note shall be overdue,
and neither the Company, the Trustee nor any agent of the Company or the
Trustee shall be affected by notice to the contrary.

         Section 3.09.    Cancellation.

         All Notes surrendered for payment, redemption, registration of
transfer or exchange shall be delivered to the Trustee and, if not already
canceled, shall be promptly canceled by it.  The Company may at any time
deliver to the Trustee for cancellation any Notes previously authenticated and
delivered hereunder which the Company may have acquired in any manner
whatsoever, and all Notes so delivered shall be promptly canceled by the
Trustee.  The Registrar and the Paying Agent shall forward to the Trustee any
Notes surrendered to them for registration of transfer or exchange, redemption
or payment.  The Trustee and no one else shall cancel all Notes surrendered for
registration of transfer, exchange, payment, replacement or cancellation.  No
Notes shall be authenticated in lieu of or in exchange for any Notes canceled
as provided in this Section 3.09 hereof, except as expressly permitted by this
Indenture.
<PAGE>   53
                                      -45-

All canceled Notes held by the Trustee shall be destroyed and certification of
their destruction delivered to the Company unless by a Company Order the
Company shall direct that the canceled Notes be returned to it.  The Trustee
shall provide the Company a list of all Notes that have been canceled from time
to time as requested by the Company.

         Section 3.10.    Computation of Interest.

         Interest on the Notes shall be computed on the basis of a 360-day year
of twelve 30-day months and, in the case of a partial month, the actual number
of days elapsed.

         Section 3.11.    Legal Holidays.

         In any case where any Interest Payment Date, Redemption Date, date
established for the payment of Defaulted Interest or Stated Maturity of any
Note shall not be a Business Day, then (notwithstanding any other provision of
this Indenture or of the Notes) payment of principal, premium, if any, or
interest need not be made on such date, but may be made on the next succeeding
Business Day with the same force and effect as if made on the Interest Payment
Date, Redemption Date, date established for the payment of Defaulted Interest
or at the Stated Maturity, as the case may be.  In such event, no interest
shall accrue with respect to such payment for the period from and after such
Interest Payment Date, Redemption Date, date established for the payment of
Defaulted Interest or Stated Maturity, as the case may be, to the next
succeeding Business Day and, with respect to any Interest Payment Date,
interest for the period from and after such Interest Payment Date shall accrue
with respect to the next succeeding Interest Payment Date.

         Section 3.12.    CUSIP and CINS Numbers.

         The Company in issuing the Notes may use "CUSIP" and "CINS" numbers
(if then generally in use), and if so, the Trustee shall use the CUSIP or CINS
numbers, as the case may be, in notices of redemption or exchange as a
convenience to Holders; provided, however, that any such notice may state that
no representation is made as to the correctness or accuracy of the CUSIP or
CINS number, as the case may be, printed in the notice or on the Notes, and
that reliance may be placed only on the other identification numbers printed on
the Notes.  The Company shall promptly notify the Trustee in writing of any
change in the CUSIP or CINS number of any type of Notes.
<PAGE>   54
                                      -46-

         Section 3.13.    Paying Agent To Hold Money in Trust.

         Each Paying Agent shall hold in trust for the benefit of the
Noteholders or the Trustee all money held by the Paying Agent for the payment
of principal of, premium, if any, or interest on the Notes, and shall notify
the Trustee of  any default by the Company in making any such payment.  Money
held in trust by the Paying Agent need not be segregated except as required by
law and in no event shall the Paying Agent be liable for any interest on any
money received by it hereunder.  The Company at any time may require the Paying
Agent to pay all money held by it to the Trustee and account for any funds
disbursed and the Trustee may at any time during the continuance of any Event
of Default, upon a Company Order to the Paying Agent, require such Paying Agent
to pay forthwith all money so held by it to the Trustee and to account for any
funds disbursed.  Upon making such payment, the Paying Agent shall have no
further liability for the money delivered to the Trustee.

         Section 3.14.    Treasury Notes.

         In determining whether the Holders of the required aggregate principal
amount of Notes have concurred in any direction, waiver, consent or notice,
Notes owned by the Company or an Affiliate of the Company shall be considered
as though they are not Outstanding, except that for the purposes of determining
whether the Trustee shall be protected in relying on any such direction, waiver
or consent, only Notes which the Trustee actually knows are so owned shall be
so considered.  The Company shall notify the Trustee, in writing, when it or
any of its Affiliates repurchases or otherwise acquires Notes, of the aggregate
principal amount of such Notes so repurchased or otherwise acquired.

         Section 3.15.    Deposits of Monies.

         Prior to 12:00 p.m. noon New York City time on each Interest Payment
Date, maturity date, Change of Control Payment Date and Asset Sale Offer
Purchase Date, the Company shall have deposited with the Paying Agent in
immediately available funds money sufficient to make cash payments, if any, due
on such Interest Payment Date, maturity date, Change of Control Payment Date
and Asset Sale Offer Purchase Date, as the case may be, in a timely manner
which permits the Paying Agent to remit payment to the Holders on such Interest
Payment Date, maturity date, Change of Control Payment Date and Asset Sale
Offer Purchase Date, as the case may be.
<PAGE>   55
                                      -47-

         Section 3.16.    Book-Entry Provisions for Global Notes.

         (a)  The Global Notes initially shall (i) be registered in the name of
the Depository or the nominee of such Depository, (ii) be delivered to the
Trustee as custodian for such Depository and (iii) bear legends as set forth in
Exhibit B.

         Members of, or participants in, the Depository ("Agent Members") shall
have no rights under this Indenture with respect to any Global Note held on
their behalf by the Depository, or the Trustee as its custodian, or under the
Global Note, and the Depository may be treated by the Company, the Trustee and
any agent of the Company or the Trustee as the absolute owner of the Global Note
for all purposes whatsoever.  Notwithstanding the foregoing, nothing herein
shall prevent the Company, the Trustee or any agent of the Company or the
Trustee from giving effect to any written certification, proxy or other
authorization furnished by the Depository or impair, as between the Depository
and its Agent Members, the operation of customary practices governing the
exercise of the rights of a Holder of any Note.

         (b)  Transfers of Global Notes shall be limited to transfers in whole,
but not in part, to the Depository, its successors or their respective
nominees.  Interests of beneficial owners in the Global Notes may be
transferred or exchanged for Physical Notes in accordance with the rules and
procedures of the Depository and the provisions of Sections 3.03 and 3.17
hereof.  In addition, Physical Notes shall be transferred to all beneficial
owners in exchange for their beneficial interests in Global Notes if (i) the
Depository notifies the Company that it is unwilling or unable to continue as
Depository for any Global Note, or that it will cease to be a "Clearing Agency"
under the Exchange Act, and in either case a successor Depository is not
appointed by the Company within 90 days of such notice or (ii) an Event of
Default has occurred and is continuing and the Registrar has received a written
request from the Depository to issue Physical Notes.

         (c)  In connection with any transfer or exchange of a portion of the
beneficial interest in any Global Note to beneficial owners pursuant to
paragraph (b), the Registrar shall (if one or more Physical Notes are to be
issued) reflect on its books and records the date and a decrease in the
principal amount of the Global Note in an amount equal to the principal amount
of the beneficial interest in the Global Note to be
<PAGE>   56
                                      -48-

transferred, and the Company shall execute, and the Trustee shall authenticate
and deliver, one or more Physical Notes of like tenor and principal amount of
authorized denominations.

         (d)  In connection with the transfer of Global Notes as an entirety to
beneficial owners pursuant to paragraph (b), the Global Notes shall be deemed
to be surrendered to the Trustee for cancellation, and the Company shall
execute, and the Trustee shall authenticate and deliver, to each beneficial
owner identified by the Depository in exchange for its beneficial interest in
the Global Notes, an equal aggregate principal amount at maturity of Physical
Notes of like tenor of authorized denominations.

         (e)  Any Physical Note constituting a Restricted Note delivered in
exchange for an interest in a Global Note pursuant to subparagraph (b), (c) or
(d) of this Section 3.16 shall, except as otherwise provided by Section 3.17
hereof, bear the Private Placement Legend.

         (f)  The Holder of any Global Note may grant proxies and otherwise
authorize any person, including Agent Members and persons that may hold
interests through Agent Members, to take any action which a Holder is entitled
to take under this Indenture or the Notes.

         Section 3.17.    Special Transfer Provisions.

         (a)  Transfers to Non-QIB Institutional Accredited Investors.  The
following additional provisions shall apply with respect to the registration of
any proposed transfer of an Initial Note to any Institutional Accredited
Investor which is not a QIB:

         (i) the Registrar shall register the transfer of any Initial Note,
    whether or not such Note bears the Private Placement Legend, if (x) the
    requested transfer is after the second anniversary of the Issue Date;
    provided, however, that neither the Company nor any Affiliate of the
    Company has held any beneficial interest in such Note, or portion thereof,
    at any time on or prior to the second anniversary of the Issue Date and
    such transfer can otherwise be lawfully made under the Securities Act
    without registering such Initial Notes thereunder or (y) the proposed
    transferee has delivered to the Registrar a certificate substantially in
    the form of Exhibit C hereto and any legal opinions and certifications
    required thereby;
<PAGE>   57
                                      -49-

         (ii)    if the proposed transferor is an Agent Member seeking to
    transfer an interest in a Global Note, upon receipt by the Registrar of (x)
    written instructions given in accordance with the Depository's and the
    Registrar's procedures and (y) the appropriate certificate, if any,
    required by clause (y) of paragraph (i) above, together with any required
    legal opinions and certifications, the Registrar shall register the
    transfer and reflect on its books and records the date and a decrease in
    the principal amount of the Global Note from which such interests are to be
    transferred in an amount equal to the principal amount of the Notes to be
    transferred and the Company shall execute and upon a Company Order, the
    Trustee shall authenticate Physical Notes in a principal amount equal to
    the principal amount of the Global Note to be transferred.

         (b) Transfers to Non-U.S. Persons.  The following additional
provisions shall apply with respect to the registration of any proposed
transfer of an Initial Note to any Non-U.S. Person:

         (i) the Registrar shall register the transfer of any Initial Note,
    whether or not such Note bears the Private Placement Legend, if (x) the
    requested transfer is after the second anniversary of the Issue Date;
    provided, however, that neither the Company nor any Affiliate of the
    Company has held any beneficial interest in such Note, or portion thereof,
    at any time on or prior to the second anniversary of the Issue Date and
    such transfer can otherwise be lawfully made under the Securities Act
    without registering such Initial Notes thereunder or (y) the proposed
    transferor has delivered to the Registrar a certificate substantially in
    the form of Exhibit D hereto;

         (ii)    if the proposed transferee is an Agent Member and the Notes to
    be transferred consist of Physical Notes which after transfer are to be
    evidenced by an interest in the Regulation S Global Note upon receipt by
    the Registrar of (x) written instructions given in accordance with the
    Depository's and the Registrar's procedures and (y) the appropriate
    certificate, if any, required by clause (y) of paragraph (i) above,
    together with any required legal opinions and certifications, the Registrar
    shall register the transfer and reflect on its books and records the date
    and an increase in the principal amount of the Regulation S Global Note in
    an amount equal to the principal amount of Physical Notes to be
    transferred, and the Trustee shall cancel the Physical Notes so
    transferred;
<PAGE>   58
                                      -50-

         (iii)   if the proposed transferor is an Agent Member seeking to
    transfer an interest in a Global Note, upon receipt by the Registrar of (x)
    written instructions given in accordance with the Depository's and the
    Registrar's procedures and (y) the appropriate certificate, if any,
    required by clause (y) of paragraph (i) above, together with any required
    legal opinions and certifications, the Registrar shall register the
    transfer and reflect on its books and records the date and (A) a decrease
    in the principal amount of the Global Note from which such interests are to
    be transferred in an amount equal to the principal amount of the Notes to
    be transferred and (B) an increase in the principal amount of the
    Regulation S Global Note in an amount equal to the principal amount of the
    Global Note to be transferred; and

         (iv)    until the 41st day after the Issue Date (the "Restricted
    Period"), an owner of a beneficial interest in the Regulation S Global Note
    may not transfer such interest to a transferee that is a U.S. person or for
    the account or benefit of a U.S. person within the meaning of Rule 902(o)
    of the Securities Act.  During the Restricted Period, all beneficial
    interests in the Regulation S Global Note shall be transferred only through
    Cedel or Euroclear, either directly if the transferor and transferee are
    participants in such systems, or indirectly through organizations that are
    participants.

         (c)  Transfers to QIBs.  The following provisions shall apply with
respect to the registration of any proposed transfer of an Initial Note to a
QIB (excluding Non-U.S. Persons):

         (i) the Registrar shall register the transfer of any Initial Note,
    whether or not such Note bears the Private Placement Legend, if (x) the
    requested transfer is after the second anniversary of the Issue Date;
    provided, however, that neither the Company nor any Affiliate of the
    Company has held any beneficial interest in such Note, or portion thereof,
    at any time on or prior to the second anniversary of the Issue Date and
    such transfer can otherwise be lawfully made under the Securities Act
    without registering such Initial Note thereunder or (y) such transfer is
    being made by a proposed transferor who has checked the box provided for on
    the form of Note stating, or has otherwise advised the Company and the
    Registrar in writing, that the sale has been made in compliance with the
    provisions of Rule 144A to a transferee who has signed
<PAGE>   59
                                      -51-

    the certification provided for on the form of Note stating, or has
    otherwise advised the Company and the Registrar in writing, that it is
    purchasing the Note for its own account or an account with respect to which
    it exercises sole investment discretion and that it and any such account is
    a QIB within the meaning of Rule 144A, and is aware that the sale to it is
    being made in reliance on Rule 144A and acknowledges that it has received
    such information regarding the Company as it has requested pursuant to Rule
    144A or has determined not to request such information and that it is aware
    that the transferor is relying upon its foregoing representations in order
    to claim the exemption from registration provided by Rule 144A;

         (ii)    if the proposed transferee is an Agent Member and the Notes to
    be transferred consist of Physical Notes which after transfer are to be
    evidenced by an interest in the 144A Global Note, upon receipt by the
    Registrar of written instructions given in accordance with the Depository's
    and the Registrar's procedures, the Registrar shall register the transfer
    and reflect on its book and records the date and an increase in the
    principal amount of the 144A Global Note in an amount equal to the
    principal amount of Physical Notes to be transferred, and the Trustee shall
    cancel the Physical Note so transferred; and

         (iii)   if the proposed transferor is an Agent Member seeking to
    transfer an interest in a Global Note, upon receipt by the Registrar of
    written instructions given in accordance with the Depository's and the
    Registrar's procedures, the Registrar shall register the transfer and
    reflect on its books and records the date and (A) a decrease in the
    principal amount of the Global Note from which interests are to be
    transferred in an amount equal to the principal amount of the Notes to be
    transferred and (B) an increase in the principal amount of the 144A Global
    Note in an amount equal to the principal amount of the Global Note to be
    transferred.

         (d)  Private Placement Legend.  Upon the registration of transfer,
exchange or replacement of Notes not bearing the Private Placement Legend, the
Registrar shall deliver Notes that do not bear the Private Placement Legend.
Upon the registration of transfer, exchange or replacement of Notes bearing the
Private Placement Legend, the Registrar shall deliver only Notes that bear the
Private Placement Legend unless (i) the circumstances contemplated by paragraph
(a)(i)(x) of this Section 3.17 exist, (ii) there is delivered to the Registrar
an
<PAGE>   60
                                      -52-

Opinion of Counsel reasonably satisfactory to the Company and the Trustee to
the effect that neither such legend nor the related restrictions on transfer
are required in order to maintain compliance with the provisions of the
Securities Act or (iii) such Note has been sold pursuant to an effective
registration statement under the Securities Act.

         (e)  Other Transfers.  If a Holder proposes to transfer a Note
constituting a Restricted Note pursuant to any exemption from the registration
requirements of the Securities Act other than as provided for by Section
3.17(a), (b) and (c) hereof, the Registrar shall only register such transfer or
exchange if such transferor delivers an Opinion of Counsel satisfactory to the
Company and the Registrar that such transfer is in compliance with the
Securities Act and the terms of this Indenture; provided, however, that the
Company may, based upon the opinion of its counsel, instruct the Registrar by a
Company Order not to register such transfer in any case where the proposed
transferee is not a QIB, Non-U.S. person or Institutional Accredited Investor.

         (f)  General.  By its acceptance of any Note bearing the Private
Placement Legend, each Holder of such a Note acknowledges the restrictions on
transfer of such Note set forth in this Indenture and in the Private Placement
Legend and agrees that it will transfer such Note only as provided in this
Indenture.

         The Registrar shall retain copies of all letters, notices and other
written communications received pursuant to Section 3.16 hereof or this Section
3.17.  The Company shall have the right to inspect and make copies of all such
letters, notices or other written communications at any reasonable time upon
the giving of reasonable prior written notice to the Registrar.

                                  ARTICLE FOUR

                       DEFEASANCE OR COVENANT DEFEASANCE

    Section 4.01.    Company's Option To Effect Defeasance or Covenant
                     Defeasance.

         The Company may, at its option by Board Resolution, at any time, with
respect to the Notes, elect to have either Section 4.02 or Section 4.03 hereof
be applied to all of the
<PAGE>   61
                                      -53-

Outstanding Notes (the "Defeased Notes"), upon compliance with the conditions
set forth below in this Article Four.

         Section 4.02.    Defeasance and Discharge.

         Upon the Company's exercise under Section 4.01 hereof of the option
applicable to this Section 4.02, the Company shall be deemed to have been
discharged from their obligations with respect to the Defeased Notes on the
date the conditions set forth below are satisfied (hereinafter, "defeasance").
For this purpose, such defeasance means that the Company shall be deemed to
have paid and discharged the entire indebtedness represented by the Defeased
Notes, which shall thereafter be deemed to be "Outstanding" only for the
purposes of Section 4.05 and the other Sections of this Indenture referred to
in (a) and (b) below, and to have satisfied all its other obligations under
such Notes and this Indenture insofar as such Notes are concerned (and the
Trustee, at the expense of the Company, and, upon Company Request, shall
execute proper instruments acknowledging the same), except for the following,
which shall survive until otherwise terminated or discharged hereunder:  (a)
the rights of Holders of Defeased Notes to receive, solely from the trust fund
described in Section 4.04 hereof and as more fully set forth in such Section,
payments in respect of the principal of, premium, if any, and interest on such
Notes when such payments are due, (b) the Company's obligations with respect to
such Defeased Notes under Sections 3.04, 3.05, 3.06, 10.02 and 10.03 hereof,
(c) the rights, powers, trusts, duties and immunities of the Trustee hereunder,
including, without limitation, the Trustee's rights under Section 6.07 hereof,
and (d) this Article Four.  Subject to compliance with this Article Four, the
Company may exercise its option under this Section 4.02 notwithstanding the
prior exercise of its option under Section 4.03 hereof with respect to the
Notes.

         Section 4.03.    Covenant Defeasance.

         Upon the Company's exercise under Section 4.01 hereof of the option
applicable to this Section 4.03, the Company shall be released from its
obligations under any covenant or provision contained in Sections 10.06 through
10.23 hereof and the provisions of Articles Eight shall not apply, with respect
to the Defeased Notes, on and after the date the conditions set forth below are
satisfied (hereinafter, "covenant defeasance"), and the Defeased Notes shall
thereafter be deemed not to be "Outstanding" for the purposes of any direction,
waiver, consent or declaration or Act of Holders (and the consequences of any
thereof) in connection with such covenants, but shall
<PAGE>   62
                                      -54-

continue to be deemed "Outstanding" for all other purposes hereunder.  For this
purpose, such covenant defeasance means that, with respect to the Defeased
Notes, the Company may omit to comply with and shall have no liability in
respect of any term, condition or limitation set forth in any such Section or
Article, whether directly or indirectly, by reason of any reference elsewhere
herein to any such Section or Article or by reason of any reference in any such
Section or Article to any other provision herein or in any other document and
such omission to comply shall not constitute a Default or an Event of Default
under Section 5.01(iii) or (iv) hereof, but, except as specified above, the
remainder of this Indenture and such Defeased Notes shall be unaffected
thereby.

         Section 4.04.    Conditions to Defeasance or Covenant Defeasance.

         The following shall be the conditions to application of either Section
4.02 or Section 4.03 hereof to the Defeased Notes:

         (1) The Company shall irrevocably have deposited or caused to be
    deposited with the Trustee (or another trustee satisfying the requirements
    of Section 6.09 hereof who shall agree to comply with the provisions of
    this Article Four applicable to it) as trust funds in trust for the purpose
    of making the following payments, specifically pledged as security for, and
    dedicated solely to, the benefit of the Holders of such Notes, (a) cash in
    an amount, or (b) U.S. Government Obligations which through the scheduled
    payment of principal, premium, if any, and interest in respect thereof in
    accordance with their terms will provide, not later than one day before the
    due date of any payment, money in an amount, or (c) a combination thereof,
    in any such case, sufficient, in the opinion of a nationally recognized
    firm of independent public accountants expressed in a written certification
    thereof delivered to the Trustee, to pay and discharge, and which shall be
    applied by the Trustee (or other qualifying trustee) to pay and discharge,
    the principal of, premium, if any, and interest on the Defeased Notes at
    the Stated Maturity of such principal or installment of principal, premium,
    if any, or interest; provided, however, that the Trustee shall have been
    irrevocably instructed to apply such cash or the proceeds of such U.S.
    Government Obligations to said payments with respect to the Notes;
<PAGE>   63
                                      -55-

         (2) No Default shall have occurred and be continuing on the date of
    such deposit or, insofar as Section 5.01(viii) hereof is concerned, at any
    time during the period ending on the ninety-first day after the date of
    such deposit (it being understood that this condition shall not be deemed
    satisfied until the expiration of such period);

         (3) Neither the Company nor any Subsidiary of the Company is an
    "insolvent person" within the meaning of any applicable Bankruptcy Law on
    the date of such deposit or at any time during the period ending on the
    ninety-first day after the date of such deposit (it being understood that
    this condition shall not be deemed satisfied until the expiration of such
    period);

         (4) Such defeasance or covenant defeasance shall not cause the Trustee
    for the Notes to have a conflicting interest in violation of Section 6.08
    hereof and for purposes of the Trust Indenture Act with respect to any
    securities of the Company;

         (5) Such defeasance or covenant defeasance shall not result in a
    breach or violation of, or constitute a default under, this Indenture or
    any other material agreement or instrument to which the Company is a party
    or by which it is bound;

         (6) In the case of an election under Section 4.02 hereof, the Company
    shall have delivered to the Trustee an Opinion of Counsel stating that (x)
    the Company has received from, or there has been published by, the Internal
    Revenue Service a ruling or (y) since the date hereof, there has been a
    change in the applicable Federal income tax law, in either case to the
    effect that, and based thereon such opinion shall confirm that, the Holders
    of the Outstanding Notes will not recognize income, gain or loss for
    Federal income tax purposes as a result of such defeasance and will be
    subject to Federal income tax on the same amounts, in the same manner and
    at the same times as would have been the case if such defeasance had not
    occurred;

         (7) In the case of an election under Section 4.03 hereof, the Company
    shall have delivered to the Trustee an Opinion of Counsel to the effect
    that the Holders of the Outstanding Notes will not recognize income, gain
    or loss for Federal income tax purposes as a result of such covenant
    defeasance and will be subject to Federal income tax
<PAGE>   64
                                      -56-

    on the same amounts, in the same manner and at the same times as would have
    been the case if such covenant defeasance had not occurred;

         (8) The Company shall have delivered to the Trustee, an Opinion of
    Counsel to the effect that, immediately following the ninety-first day
    after the deposit, the trust funds established pursuant to this Article
    will not be subject to the effect of any applicable bankruptcy, insolvency,
    reorganization or similar laws affecting creditors' rights generally under
    any applicable U.S. Federal or state law;

         (9) The Company shall have delivered to the Trustee an Officers'
    Certificate stating that the deposit made by the Company pursuant to its
    election under Section 4.02 or 4.03 hereof was not made by the Company with
    the intent of preferring the Holders over the other creditors of the
    Company or with the intent of defeating, hindering, delaying or defrauding
    creditors of the Company or others; and

         (10)    The Company shall have delivered to the Trustee an Officers'
    Certificate and an Opinion of Counsel, each stating that (i) all conditions
    precedent (other than  conditions requiring the passage of time) provided
    for relating to either the defeasance under Section 4.02 or the covenant
    defeasance under Section 4.03 (as the case may be) have been complied with
    as contemplated by this Section 4.04 and (ii) if any other Indebtedness of
    the Company shall then be outstanding or committed, such defeasance or
    covenant defeasance will not violate the provisions of the agreements or
    instruments evidencing such Indebtedness.

         Opinions required to be delivered under this Section may have such
qualifications as are customary for opinions of the type required and
reasonably acceptable to the Trustee.

         Section 4.05.    Deposited Money and U.S. Government Obligations To 
                          Be Held in Trust; Other Miscellaneous Provisions.

         Subject to the proviso of the last paragraph of Section 10.03, all
money and U.S. Government Obligations (including the proceeds thereof)
deposited with the Trustee (or other qualifying trustee, collectively for
purposes of this Section 4.05, the "Trustee") pursuant to Section 4.04 in
respect of the Defeased Notes shall be held in trust and applied by the
Trustee,
<PAGE>   65
                                      -57-

in accordance with the provisions of such Notes and this Indenture, to the
payment, either directly or through any Paying Agent (other than the Company)
as the Trustee may determine, to the Holders of such Notes of all sums due and
to become due thereon in respect of principal, premium, if any, and interest,
but such money need not be segregated from other funds except to the extent
required by law.

         The Company shall pay and indemnify the Trustee and hold it harmless
against any tax, fee or other charge imposed on or assessed against the U.S.
Government Obligations deposited pursuant to Section 4.04 or the principal,
premium, if any, and interest received in respect thereof other than any such
tax, fee or other charge which by law is for the account of the Holders of the
Defeased Notes.

         Anything in this Article Four to the contrary notwithstanding, the
Trustee shall deliver or pay to the Company from time to time upon Company
Request any money or U.S. Government Obligations held by it as provided in
Section 4.04 which, in the opinion of an internationally recognized firm of
independent public accountants expressed in a written certification thereof
delivered to the Trustee, are in excess of the  amount thereof which would then
be required to be deposited to effect an equivalent defeasance or covenant
defeasance.

         Section 4.06.    Reinstatement.

         If the Trustee or Paying Agent is unable to apply any money or U.S.
Government Obligations in accordance with Section 4.02 or 4.03 hereof, as the
case may be, by reason of any order or judgment of any court or governmental
authority enjoining, restraining or otherwise prohibiting such application,
then the obligations of the Company under this Indenture and the Notes shall be
revived and reinstated as though no deposit had occurred pursuant to Section
4.02 or 4.03 hereof, as the case may be, until such time as the Trustee or
Paying Agent is permitted to apply all such money and U.S. Government
Obligations in accordance with Section 4.02 or 4.03 hereof, as the case may be;
provided, however, that if the Company makes any payment of principal, premium,
if any, or interest on any Note following the reinstatement of its obligations,
the Company shall be subrogated to the rights of the Holders of such Notes to
receive such payment from the money and U.S. Government Obligations held by the
Trustee or Paying Agent.
<PAGE>   66
                                      -58-

                                  ARTICLE FIVE

                                    REMEDIES

         Section 5.01.    Events of Default.

         "Event of Default", wherever used herein, means any one of the
following events (whatever the reason for such Event of Default and whether it
shall be voluntary or involuntary or be effected by operation of law or
pursuant to any judgment, decree or order of any court or any order, rule or
regulation of any administrative or governmental body):

         (i)     default in the payment of interest on the Notes when it becomes
    due and payable and continuance of such default for a period of 30-days or
    more; or

         (ii)    default in the payment of the principal of, or premium, if
    any, on the Notes when due; or

         (iii)   default in the performance, or breach, of any covenant
    described under Section 10.10, Section 10.15 or Article Eight; or

         (iv)    default in the performance, or breach, of any term, covenant
    or agreement in the Notes, this Indenture (other than defaults specified in
    clause (i), (ii) or (iii) above) and continuance of such default or breach
    for a period of 30 days or more after written notice to the Company by the
    Trustee or to the Company and the Trustee by the holders of at least 25% in
    aggregate principal amount of the Outstanding Notes (in each case, when
    such notice is deemed received in accordance with this Indenture); or

         (v)     failure to perform any term, covenant, condition or provision
    of one or more classes or issues of Indebtedness in an aggregate principal
    amount of $7.5 million or more under which the Company or a Material
    Restricted Subsidiary is obligated, and either (a) such Indebtedness is
    already due and payable in full or (b) such failure results in the
    acceleration of the maturity of such Indebtedness; or

         (vi)    any holder of at least $7.5 million in aggregate principal
    amount of Indebtedness of the Company or any Material Restricted Subsidiary
    shall commence judicial proceedings
<PAGE>   67
                                      -59-

    or take any other action to foreclose upon or dispose of assets of the
    Company or any Material Restricted Subsidiary having an aggregate Fair
    Market Value, individually or in the aggregate, of $7.5 million or more or
    shall have exercised any right under applicable law or applicable security
    documents to take ownership of any such assets in lieu of foreclosure;
    provided that, in any such case, the Company or any Material Restricted
    Subsidiary shall not have obtained, prior to any such foreclosure or
    disposition of assets, a stay of all such actions that remains in effect;
    or

         (vii)   one or more judgments, orders or decrees for the payment of
    money of $7.5 million or more, either individually or in the aggregate,
    shall be entered into against the Company or any Material Restricted
    Subsidiary or any of their respective properties and shall not be
    discharged and there shall have been a period of 60 days or more during
    which a stay of enforcement of such judgment or order, by reason of pending
    appeal or otherwise, shall not be in effect; or

         (viii)  the Company or any Material Restricted Subsidiary of the
    Company pursuant to or under or within the meaning of any Bankruptcy Law;
    or

             (A) commences a voluntary case or proceeding;

             (B) consents to the making of a Bankruptcy Order in an involuntary
         case or proceeding or the commencement of any case against it;

             (C) consents to the appointment of a Custodian of it or for any
         substantial part of its property;

             (D) makes a general assignment for the benefit of its creditors;

             (E) files an answer or consent seeking reorganization or relief;

             (F) shall admit in writing its inability to pay its debts
         generally; or

             (G) consents to the filing of a petition in bankruptcy; or
<PAGE>   68
                                      -60-

         (ix)    a court of competent jurisdiction in any involuntary case or
    proceeding enters a Bankruptcy Order against the Company or any Material
    Restricted Subsidiary, and such Bankruptcy Order remains unstayed and in
    effect for 60 consecutive days; or

         (x) a Custodian shall be appointed out of court  with respect to the
    Company or any Material Restricted Subsidiary or with respect to all or any
    substantial part of the assets or properties of the Company or any Material
    Restricted Subsidiary.

         Section 5.02.    Acceleration of Maturity; Rescission and Annulment.

         If an Event of Default (other than an Event of Default specified in
clause (viii), (ix) or (x) of Section 5.01 hereof with respect to the Company)
occurs and is continuing, then the Trustee or the holders of at least 25% in
principal amount of the Outstanding Notes may, by written notice, and the
Trustee upon the request of the holders of not less than 25% in principal
amount of the Outstanding Notes shall, declare the principal amount of, premium
(if any) on, and any accrued and unpaid interest on, all outstanding Notes to
be immediately due and payable and upon any such declaration such amounts shall
become immediately due and payable.  If an Event of Default specified in clause
(viii), (ix) or (x) above with respect to the Company occurs and is continuing,
then the principal amount of, premium (if any) on, and any accrued and unpaid
interest on, all Outstanding Notes shall ipso facto become and be immediately
due and payable without any declaration or other act on the part of the Trustee
or any holder.

         After a declaration of acceleration, the holders of a majority in
aggregate principal amount of Outstanding Notes may, by notice to the Trustee,
rescind such declaration of acceleration if all existing Events of Default,
other than nonpayment of the principal of, premium (if any) on, and any accrued
and unpaid interest on, the Notes that has become due solely as a result of
such acceleration, have been cured or waived and if the rescission of
acceleration would not conflict with any judgment or decree.

         Section 5.03.    Collection of Indebtedness and Suits for Enforcement
                          by Trustee.      _

         The Company covenants that if an Event of Default specified in Section
5.01(i) or 5.01(ii) shall have occurred
<PAGE>   69
                                      -61-

and be continuing, the Company will, upon demand of the Trustee, pay to the
Trustee, for the benefit of the Holders of such Notes, the whole amount then
due and payable on such Notes for principal, premium, if any, and interest,
with interest upon the overdue principal, premium, if any, and, to the extent
that payment of such interest shall be legally enforceable, upon overdue
installments of interest, at the rate then borne by the Notes; and, in addition
thereto, such further amount as shall be sufficient to cover the costs and
expenses of collection, including the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel.

         If the Company fails to pay such amounts forthwith upon such demand,
the Trustee, in its own name and as trustee of an express trust, may, but is
not obligated under this paragraph to, institute a judicial proceeding for the
collection of the sums so due and unpaid and may, but is not obligated under
this paragraph to, prosecute such proceeding to judgment or final decree, and
may, but is not obligated under this paragraph to, enforce the same against the
Company or any other obligor upon the Notes and collect the moneys adjudged or
decreed to be payable in the manner provided by law out of the property of the
Company or any other obligor upon the Notes, wherever situated.

         If an Event of Default occurs and is continuing, the Trustee may in
its discretion, but is not obligated under this paragraph to, (i) proceed to
protect and enforce its rights and  the rights of the Holders under this
Indenture by such appropriate private or judicial proceedings as the Trustee
shall deem most effectual to protect and enforce such rights, whether for the
specific enforcement of any covenant or agreement contained in this Indenture
or in aid of the exercise of any power granted herein or (ii) proceed to
protect and enforce any other proper remedy.  No recovery of any such judgment
upon any property of the Company shall affect or impair any rights, powers or
remedies of the Trustee or the Holders.

         Section 5.04.    Trustee May File Proofs of Claims.

         In case of the pendency of any receivership, insolvency, liquidation,
bankruptcy, reorganization, arrangement, adjustment, composition or other
judicial proceeding relative to the Company or any other obligor upon the Notes
or the property of the Company or of such other obligor or their creditors, the
Trustee (irrespective of whether the principal of the Notes shall then be due
and payable as therein expressed or by declaration or otherwise and
irrespective of whether the
<PAGE>   70
                                      -62-

Trustee shall have made any demand on the Company for the payment of overdue
principal or interest) shall be entitled and empowered, by intervention in such
proceeding or otherwise,

         (a)  to file and prove a claim for the whole amount of principal,
premium, if any, and interest owing and unpaid in respect of the Notes and to
file such other papers or documents as may be necessary or advisable in order
to have the claims of the Trustee (including any claim for the reasonable
compensation, fees, expenses, disbursements and advances of the Trustee, its
agents and counsel) and of the Holders allowed in such judicial proceeding, and

         (b)  to collect and receive any moneys or other property payable or
deliverable on any such claims and to distribute the same;

and any Custodian, in any such judicial proceeding is hereby authorized by each
Holder to make such payments to the Trustee and, in the event that the Trustee
shall consent to the making of such payments directly to the Holders, to pay
the Trustee any amount due it for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, and any
other amounts due the Trustee under Section 6.07 hereof.

         Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder any plan of
reorganization, arrangement, adjustment or composition affecting the Notes or
the rights of any Holder thereof, or to authorize the Trustee to vote in
respect of the claim of any Holder in any such proceeding.

         Section 5.05.    Trustee May Enforce Claims Without Possession of
                          Notes.

         All rights of action and claims under this Indenture or the Notes may
be prosecuted and enforced by the Trustee without the possession of any of the
Notes or the production thereof in any proceeding relating thereto, and any
such proceeding instituted by the Trustee shall be brought in its own name and
as trustee of an express trust, and any recovery of judgment shall, after
provision for the payment of the reasonable compensation, fees, expenses,
disbursements and advances of the Trustee, its agents and counsel, be for the
ratable benefit of the Holders of the Notes in respect of which such judgment
has been recovered.
<PAGE>   71
                                      -63-

         Section 5.06.    Application of Money Collected.

         Any money collected by the Trustee pursuant to this Article shall be
applied in the following order, at the date or dates fixed by the Trustee and,
in case of the distribution of such money on account of principal, premium, if
any, or interest, upon presentation of the Notes and the notation thereon of
the payment if only partially paid and upon surrender thereof if fully paid:

         First:  to the Trustee for amounts due under Section 6.07;

         Second:  to Holders for interest accrued on the Notes, ratably,
    without preference or priority of any kind, according to the amounts due
    and payable on the Notes for interest;

         Third:  to Holders for principal and premium, if any, amounts owing
    under the Notes, ratably, without preference or priority of any kind,
    according to the amounts due and payable on the Notes for principal and
    premium, if any; and

         Fourth:  the balance, if any, to the Company.

         The Trustee, upon prior written notice to the Company, may fix a
record date and payment date for any payment to Noteholders pursuant to this
Section 5.06.

         Section 5.07.    Limitation on Suits.

         No Holder of any Notes shall have any right to institute any
proceeding, judicial or otherwise, with respect to this Indenture, or for the
appointment of a receiver or trustee, or for any other remedy hereunder, unless

         (a)  such Holder has previously given written notice to the Trustee of
    a continuing Event of Default;

         (b)  the Holders of not less than 25% in principal amount of the
    Outstanding Notes shall have made written request to the Trustee to
    institute proceedings in respect of such Event of Default in its own name
    as Trustee hereunder;

         (c)  such Holder or Holders have offered to the Trustee reasonable
    indemnity against the costs, expenses and
<PAGE>   72
                                      -64-

    liabilities to be incurred in compliance with such request;

         (d)  the Trustee for 60 days after its receipt of such notice, request
    and offer of indemnity has failed to institute any such proceeding; and

         (e)  no direction inconsistent with such written request has been
    given to the Trustee during such 60-day period by the Holders of a majority
    in aggregate principal amount of the Outstanding Notes;

it being understood and intended that no one or more Holders shall have any
right in any manner whatever by virtue of, or by availing of, any provision of
this Indenture, any Note or any Guarantee to affect, disturb or prejudice the
rights of any other Holders, or to obtain or to seek to obtain priority or
preference over any other Holders or to enforce any right under this Indenture,
any Note or any Guarantee, except in the manner provided in this Indenture and
for the equal and ratable benefit of all the Holders.

         Section 5.08.    Unconditional Right of Holders To Receive Principal,
                          Premium and Interest.

         Notwithstanding any other provision in this Indenture, the Holder of
any Note shall have the right, which is absolute and unconditional, to receive
cash payment of the principal of, premium, if any, and (subject to Section 3.07
hereof) interest on such Note on the respective Stated Maturities expressed in
such Note (or, in the case of redemption, on the respective Redemption Date)
and to institute suit for the enforcement of any such payment, and such rights
shall not be impaired without the consent of such Holder.

         Section 5.09.    Restoration of Rights and Remedies.

         If the Trustee or any Holder has instituted any proceeding to enforce
any right or remedy under this Indenture or any Note and such proceeding has
been discontinued or abandoned for any reason, or has been determined adversely
to the Trustee or to such Holder, then and in every such case the Company, the
Trustee and the Holders shall, subject to any determination in such proceeding,
be restored severally and respectively to their former positions hereunder, and
thereafter all rights and remedies of the Trustee and the Holders shall
continue as though no such proceeding had been instituted.
<PAGE>   73
                                      -65-

         Section 5.10.    Rights and Remedies Cumulative.

         Except as provided in Section 3.06, no right or remedy herein
conferred upon or reserved to the Trustee or to the Holders is intended to be
exclusive of any other right or remedy, and every right and remedy shall, to
the extent permitted by law, be cumulative and in addition to every other right
and remedy given hereunder or now or hereafter existing at law or in equity or
otherwise.  The assertion or employment of any right or remedy hereunder, or
otherwise, shall not prevent the concurrent assertion or employment of any
other appropriate right or remedy.

         Section 5.11.    Delay or Omission Not Waiver.

         No delay or omission of the Trustee or of any Holder of any Note to
exercise any right or remedy accruing upon any Event of Default shall impair
any such right or remedy or constitute a waiver of any such Event of Default or
an acquiescence therein.  Every right and remedy given by this Article Five or
by law to the Trustee or to the Holders may be exercised from time to time, and
as often as may be deemed expedient, by the Trustee or by the Holders, as the
case may be.

         Section 5.12.    Control by Majority.

         The Holders of a majority in aggregate principal amount of the
Outstanding Notes shall have the right to direct the time, method and place of
conducting any proceeding for any remedy available to the Trustee, or
exercising any trust or power conferred on the Trustee, provided, however,
that:

         (a)  such direction shall not be in conflict with any rule of law or
with this Indenture or any Note or expose the Trustee to personal liability;
and

         (b)  the Trustee may take any other action deemed proper by the
Trustee which is not inconsistent with such direction.

         Section 5.13.    Waiver of Past Defaults.

         The Holders of not less than a majority in aggregate principal amount
of the Outstanding Notes may on behalf of the Holders of all the Notes waive
any past Default hereunder and its consequences, except a Default
<PAGE>   74
                                      -66-

         (a)  in the payment of the principal of, premium, if any, or interest
on any Note or

         (b)  in respect of a covenant or provision hereof which under Article
Nine cannot be modified or amended without the consent of the Holder of each
Outstanding Note affected thereby.

         Upon any such waiver, such Default shall cease to exist, and any Event
of Default arising therefrom shall be deemed to have been cured, for every
purpose of this Indenture; but no such waiver shall extend to any subsequent or
other  Default or Event of Default or impair any right consequent thereon.

         Section 5.14.    Undertaking for Costs.

         All parties to this Indenture agree, and each Holder of any Note by
his acceptance thereof shall be deemed to have agreed, that any court may in
its discretion require, in any suit for the enforcement of any right or remedy
under this Indenture, or in any suit against the Trustee for any action taken,
suffered or omitted by it as Trustee, the filing by any party litigant in such
suit of an undertaking to pay the costs of such suit, and that such court may
in its discretion assess reasonable costs, including reasonable attorneys'
fees, against any party litigant in such suit, having due regard to the merits
and good faith of the claims or defenses made by such party litigant; but the
provisions of this Section 5.14 shall not apply to any suit instituted by the
Trustee, to any suit instituted by any Holder, or group of Holders, holding in
the aggregate more than 10% in principal amount of the Outstanding Notes, or to
any suit instituted by any Holder for the enforcement of the payment of the
principal of, premium, if any, or interest on any Note on or after the
respective Stated Maturities expressed in such Note (or, in the case of
redemption, on or after the respective Redemption Dates).

         Section 5.15.    Waiver of Stay, Extension or Usury Laws.

         The Company covenants (to the extent that it may lawfully do so) that
it will not at any time insist upon, or plead, or in any manner whatsoever
claim or take the benefit or advantage of, any stay or extension law or any
usury or other law wherever enacted, now or at any time hereafter in force,
which would prohibit or forgive the Company from paying all or any portion of
the principal of, premium, if any, or interest on the Notes contemplated herein
or in the Notes or which may
<PAGE>   75
                                      -67-

affect the covenants or the performance of this Indenture; and the Company (to
the extent that it may lawfully do so) hereby expressly waives all benefit or
advantage of any such law, and covenants that it will not hinder, delay or
impede the execution of any power herein granted to the Trustee, but will
suffer and permit the execution of every such power as though no such law had
been enacted.

         Section 5.16.    Unconditional Right of Holders To Receive Payment.

         Notwithstanding any other provision in this Indenture and any other
provision of any Note, the right of any Holder of any Note to receive payment
of the principal of, premium, if any, and interest on such Note on or after the
respective Stated Maturities (or the respective Redemption Dates, in the case
of redemption) expressed in such Note, or after such respective dates, shall
not be impaired or affected without the consent of such Holder.

                                  ARTICLE SIX

                                  THE TRUSTEE

         Section 6.01.    Certain Duties and Responsibilities.

         (a)  Except during the continuance of an Event of Default,

         (1) the Trustee undertakes to perform such duties and only such duties
    as are specifically set forth in this Indenture, and no implied covenants
    or obligations shall be read into this Indenture against the Trustee; and

         (2) in the absence of bad faith on its part, the Trustee may
    conclusively rely, as to the truth of the statements and the correctness of
    the opinions expressed therein, upon certificates or opinions furnished to
    the Trustee and conforming to the requirements of this Indenture; but in
    the case of any such certificates or opinions which by provision hereof are
    specifically required to be furnished to the Trustee, the Trustee shall be
    under a duty to examine the same to determine whether or not they conform
    to the requirements of this Indenture.
<PAGE>   76
                                      -68-

         (b)  During the existence of an Event of Default, the Trustee is
required to exercise such rights and powers vested in it under this Indenture
and use the same degree of care and skill in its exercise thereof as a prudent
person would exercise under the circumstances in the conduct of such person's
own affairs.

         (c)  No provision of this Indenture shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own  willful misconduct, except that no provision of this
Indenture shall require the Trustee to expend or risk its own funds or
otherwise incur any financial liability in the performance of any of its duties
hereunder, or in the exercise of any of its rights or powers, if it shall have
reasonable grounds for believing that repayment of such funds or adequate
indemnity against such risk or liability is not reasonably assured to it.

         (d)  Whether or not therein expressly so provided, every provision of
this Indenture relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section 6.01.

         Section 6.02.    Notice of Defaults.

         Within 45 days after the occurrence of any Default, the Trustee shall
transmit by mail to all Holders, as their names and addresses appear in the
Note Register, notice of such Default hereunder known to the Trustee, unless
such Default shall have been cured or waived; provided, however, that, except
in the case of a Default in the payment of the principal of, premium, if any,
or interest on any Note, the Trustee shall be protected in withholding such
notice if and so long as a trust committee of Responsible Officers of the
Trustee in good faith determines that the withholding of such notice is in the
interest of the Holders.

         Section 6.03.    Certain Rights of Trustee.

         Subject to Section 6.01 hereof and the provisions of Section 315 of
the Trust Indenture Act:

         (a)  the Trustee may rely and shall be protected in acting or
refraining from acting upon any resolution, certificate, statement, instrument,
opinion, report, notice, request, direction, consent, order, bond, debenture,
note,  other evidence of indebtedness or other paper or document believed by it
<PAGE>   77
                                      -69-

to be genuine and to have been signed or presented by the proper party or
parties;

         (b)  any request or direction of the Company mentioned herein shall be
sufficiently evidenced by a Company Request or Company Order and any resolution
of the Board may be sufficiently evidenced by a Board Resolution thereof;

         (c)  the Trustee may consult with counsel and any written advice of
such counsel or any Opinion of Counsel shall be full and complete authorization
and protection in respect of any action taken, suffered or omitted by it
hereunder in good faith and in reliance thereon in accordance with such advice
or Opinion of Counsel;

         (d)  the Trustee shall be under no obligation to exercise any of the
rights or powers vested in it by this Indenture at the request or direction of
any of the Holders pursuant to this Indenture, unless such Holders shall have
offered to the Trustee reasonable security or indemnity against the costs,
expenses and liabilities which might be incurred by the Trustee in compliance
with such request or direction;

         (e)  the Trustee shall not be liable for any action taken or omitted
by it in good faith and believed by it to be authorized or within the
discretion, rights or powers conferred upon it by this Indenture other than any
liabilities arising out of its own negligence;

         (f)  the Trustee shall not be bound to make any investigation into the
facts or matters stated in any resolution, certificate, statement, instrument,
opinion, report, notice, request, direction, consent, order, approval,
appraisal, bond, debenture, note, coupon, security, other evidence of
indebtedness or other paper or document unless requested in writing so to do by
the Holders of not less than a majority in aggregate principal amount of the
Notes then Outstanding; provided, however, that, if the payment within a
reasonable time to the Trustee of the costs, expenses or liabilities likely to
be incurred by it in the making of such investigation is, in the opinion of the
Trustee, not reasonably assured to the Trustee by the security afforded to it
by the terms of this Indenture, the Trustee may require reasonable indemnity
against such expenses or liabilities as a condition to proceeding; the
reasonable expenses of every such investigation shall be paid by the Company
or, if paid by the Trustee or any predecessor Trustee, shall be repaid by the
Company upon demand; provided, further, the Trustee in its discretion may make
such further inquiry or
<PAGE>   78
                                      -70-

investigation into such facts or matters as it may deem fit, and, if the
Trustee shall determine to make such further inquiry or investigation, it shall
be entitled to examine  the books, records and premises of the Company,
personally or by agent or attorney; and

         (g)  the Trustee may execute any of the trusts or powers hereunder or
perform any duties hereunder either directly or by or through agents or
attorneys and the Trustee shall not be responsible for any misconduct or
negligence on the part of any agent or attorney appointed with due care by it
hereunder.

         (h) Except with respect to Section 10.01, the Trustee shall have no
duty to inquire as to the performance of the Company's covenants in Article
Ten.  In addition, the Trustee shall not be deemed to have knowledge of any
Default or Event of Default except (i) any Event of Default occurring pursuant
to Sections 5.01(i), 5.01(ii) and 10.01 or (ii) any Default or Event of Default
of which the Trustee shall have received written notification or obtained
actual knowledge.

         Section 6.04.    Trustee Not Responsible for Recitals, Dispositions of
                          Notes or Application of Proceeds Thereof.

         The recitals contained herein and in the Notes, except the Trustee's
certificates of authentication, shall be taken as the statements of the
Company, and the Trustee assumes no responsibility for their correctness.  The
Trustee makes no representations as to the validity or sufficiency of this
Indenture or of the Notes except that the Trustee represents that it is duly
authorized to execute and deliver this Indenture, authenticate the Notes and
perform its obligations hereunder and that the statements made by it in a
Statement of Eligibility and Qualification on Form T-1, if any, to be supplied
to the Company are true and accurate subject to the qualifications set forth
therein.  The Trustee shall not be accountable for the use or application by
the Company of Notes or the proceeds thereof.

         Section 6.05.    Trustee and Agents May Hold Notes; Collections; Etc.

         The Trustee, any Paying Agent, Registrar or any other agent of the
Company, in its individual or any other capacity, may become the owner or
pledgee of Notes, with the same rights it would have if it were not the
Trustee, Paying Agent, Registrar
<PAGE>   79
                                      -71-

or such other agent and, subject to Section 6.08 hereof and Sections 310 and
311 of the Trust Indenture Act, may otherwise deal with the Company and
receive, collect, hold and retain collections from the Company with the same
rights it would have if it were not the Trustee, Paying Agent, Registrar or
such other agent.

         Section 6.06.    Money Held in Trust.

         All moneys received by the Trustee shall, until used or applied as
herein provided, be held in trust for the  purposes for which they were
received, but need not be segregated from other funds except to the extent
required herein or by law.  The Trustee shall not be under any liability for
interest on any moneys received by it hereunder.

         Section 6.07.    Compensation and Indemnification of Trustee and Its 
                          Prior Claim.

         The Company covenants and agrees:  (a) to pay to the Trustee from time
to time, and the Trustee shall be entitled to, reasonable compensation for all
services rendered by it hereunder (which shall not be limited by any provision
of law in regard to the compensation of a trustee of an express trust); (b) to
reimburse the Trustee and each predecessor Trustee upon its request for all
reasonable expenses, fees, disbursements and advances incurred or made by or on
behalf of it in accordance with any of the provisions of this Indenture
(including the reasonable compensation, fees, and the expenses and
disbursements of its counsel and of all agents and other persons not regularly
in its employ), except any such expense, disbursement or advance as may arise
from its negligence or bad faith; and (c) to indemnify the Trustee and each
predecessor Trustee for, and to hold it harmless against, any loss, liability
or expense incurred without negligence or bad faith on its part, arising out of
or in connection with the acceptance or administration of this Indenture or in
respect of the trusts hereunder and its duties hereunder, including enforcement
of this Section 6.07.  The obligations of the Company under this Section to
compensate and indemnify the Trustee and each predecessor Trustee and to pay or
reimburse the Trustee and each predecessor Trustee for expenses, fees,
disbursements and advances shall constitute an additional obligation hereunder
and shall survive the satisfaction and discharge of this Indenture.  To secure
the obligations of the Company to the Trustee under this Section 6.07, the
Trustee shall have a prior Lien upon all property and funds held or collected
by the Trustee as such,
<PAGE>   80
                                      -72-

except funds and property paid by the Company and held in trust for the benefit
of the Holders of particular Notes.

         Section 6.08.    Conflicting Interests.

         The Trustee shall be subject to and comply with the provisions of
Section 310(b) of the Trust Indenture Act.

         Section 6.09.    Corporate Trustee Required; Eligibility.

         There shall at all times be a Trustee hereunder which shall be
eligible to act as Trustee under Trust Indenture Act Sections 310(a)(1) and (2)
and which shall have a combined capital and surplus of at least $25,000,000,
and have a Corporate Trust Office in the Borough of Manhattan in The City of
New York, State of New York.  If such corporation publishes reports of
condition at least annually, pursuant to law or to the requirements of any
Federal, state, territorial or District of Columbia supervising or examining
authority, then for the purposes of this Section, the combined capital and
surplus of such corporation shall be deemed to be its combined capital and
surplus as set forth in its most recent report of condition so published.  If
at any time the Trustee shall cease to be eligible in accordance with the
provisions of this Section, the Trustee shall resign immediately in the manner
and with the effect hereinafter specified in this Article.

         Section 6.10.    Resignation and Removal; Appointment of Successor
                          Trustee.

         (a)  No resignation or removal of the Trustee and no appointment of a
successor Trustee pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee under Section 6.11.

         (b)  The Trustee, or any trustee or trustees hereinafter appointed,
may at any time resign by giving written notice thereof to the Company at least
20 Business Days prior to the date of such proposed resignation.  Upon
receiving such notice of resignation, the Company shall promptly appoint a
successor trustee by written instrument executed by authority of the Board, a
copy of which shall be delivered to the resigning Trustee and a copy to the
successor Trustee.  If an instrument of acceptance by a successor Trustee shall
not have been delivered to the Trustee within 20 Business Days after the giving
of such notice of resignation, the resigning Trustee may, or (if an instrument
of acceptance by a successor Trustee shall not
<PAGE>   81
                                      -73-

have been delivered to the Trustee within 30 Business Days after the giving of
such notice of resignation) any Holder who has been a bona fide Holder of a
Note for at least six months may, on behalf of himself and all others similarly
situated, petition any court of competent jurisdiction for the appointment of a
successor Trustee.  Such court may thereupon, after such notice, if any, as it
may deem proper, appoint a successor Trustee.

         (c)  The Trustee may be removed at any time by an Act of the Holders
of a majority in principal amount of the Outstanding Notes, delivered to the
Trustee and to the Company.

         (d)  If at any time:

         (1) the Trustee shall fail to comply with the provisions of Section
    310(b) of the Trust Indenture Act in accordance with Section 6.08 hereof
    after written request therefor by the Company or by any Holder who has been
    a bona fide Holder of a Note for at least six months, or

         (2) the Trustee shall cease to be eligible under Section 6.09 hereof
    and shall fail to resign after written request therefor by the Company or
    by any Holder who has been a bona fide Holder of a Note for at least six
    months, or

         (3) the Trustee shall become incapable of acting or shall be adjudged
    a bankrupt or insolvent, or a receiver of the Trustee or of its property
    shall be appointed or any public officer shall take charge or control of
    the Trustee or of its property or affairs for the purpose or
    rehabilitation, conservation or liquidation,

then, in any case, (i) the Company by a Board Resolution may remove the
Trustee, or (ii) subject to Section 5.14, the Holder of any Note who has been a
bona fide Holder of a Note for at least six months may, on behalf of himself
and all others similarly situated, petition any court of competent jurisdiction
for the removal of the Trustee and the appointment of a successor Trustee.
Such court may thereupon, after such notice, if any, as it may deem proper and
prescribe, remove the Trustee and appoint a successor Trustee.

         (e)  If the Trustee shall resign, be removed or become incapable of
acting, or if a vacancy shall occur in the office of Trustee for any cause, the
Company, by a Board Resolution, shall promptly appoint a successor Trustee.
If, within
<PAGE>   82
                                      -74-

one year after such resignation, removal or incapability, or the occurrence of
such vacancy, a successor Trustee shall be appointed by Act of the Holders of a
majority in principal amount of the Outstanding Notes delivered to the Company
and the retiring Trustee, the successor Trustee so appointed shall, forthwith
upon its acceptance of such appointment, become the successor Trustee and
supersede the successor Trustee appointed by the Company.  If no successor
Trustee shall have been so appointed by the Company or the Holders of the Notes
and accepted appointment in the manner hereinafter provided, the Holder of any
Note who has been a bona fide Holder for at least six months may, subject to
Section 5.14, on behalf of himself and all others similarly situated, petition
any court of competent jurisdiction for the appointment of a successor Trustee.

         (f)  The Company shall give notice of each resignation and each
removal of the Trustee and each appointment of a successor Trustee by mailing
written notice of such event by first-class mail, postage prepaid, to the
Holders of Notes as their names and addresses appear in the Note Register.
Each notice shall include the name of the successor Trustee and the address of
its Corporate Trust Office.

         Section 6.11.    Acceptance of Appointment by Successor.

         Every successor Trustee appointed hereunder shall execute, acknowledge
and deliver to the Company and to the retiring Trustee an instrument accepting
such appointment, and thereupon the resignation or removal of the retiring
Trustee shall become effective and such successor Trustee, without any further
act, deed or conveyance, shall become vested with all the rights, powers,
trusts and duties of the retiring Trustee as if originally named as Trustee
hereunder; but, nevertheless, on the written request of the Company or the
successor Trustee, upon payment of amounts due it pursuant to Section 6.07,
such retiring Trustee shall duly assign, transfer and deliver to the successor
Trustee all moneys and property at the time held by it hereunder and shall
execute and deliver an instrument transferring to such successor Trustee all
the rights, powers, duties and obligations of the retiring Trustee.  Upon
request of any such successor Trustee, the Company shall execute any and all
instruments for more fully and certainly vesting in and confirming to such
successor Trustee all such rights and powers.  Any Trustee ceasing to act
shall, nevertheless, retain a prior claim upon all property or funds held or
collected by such Trustee to secure any amounts then due it pursuant to the
provisions of Section 6.07.
<PAGE>   83
                                      -75-

         No successor Trustee with respect to the Notes shall accept
appointment as provided in this Section 6.11 unless at the time of such
acceptance such successor Trustee shall be eligible to act as Trustee under
this Article.

         Upon acceptance of appointment by any successor Trustee as provided in
this Section 6.11, the successor shall give notice thereof to the Holders of
the Notes, by mailing such notice to such Holders at their addresses as they
shall appear on the Note Register.  If the acceptance of appointment is
substantially contemporaneous with the resignation, then the notice called for
by the preceding sentence may be combined with the notice called for by Section
6.10.  If the Company fails to give such notice within 10 days after acceptance
of appointment by the successor Trustee, the successor Trustee shall cause such
notice to be given at the expense of the Company.

         Section 6.12.    Merger, Conversion, Amalgamation, Consolidation or
                          Succession to Business.

         Any corporation into which the Trustee may be merged or converted or
with which it may be consolidated or amalgamated, or any corporation resulting
from any merger, conversion, amalgamation or consolidation to which the Trustee
shall be a party, or any corporation succeeding to all or substantially all of
the corporate trust business of the Trustee, shall be the successor of the
Trustee hereunder without the execution or filing of any paper or any further
act on the part of any of the parties hereto, provided such corporation shall
be eligible under this Article Six to serve as Trustee hereunder.

         In case at the time such successor to the Trustee under this Section
6.12 shall succeed to the trusts created by this Indenture any of the Notes
shall have been authenticated but not delivered, any such successor to the
Trustee may adopt the certificate of authentication of any predecessor Trustee
and deliver such Notes so authenticated; and, in case at that time any of the
Notes shall not have been authenticated, any successor to the Trustee under
this Section 6.12 may authenticate such Notes either in the name of any
predecessor hereunder or in the name of the successor Trustee; and in all such
cases such certificate shall have the full force which it is anywhere in the
Notes or in this Indenture provided that the certificate of the Trustee shall
have been authenticated.
<PAGE>   84
                                      -76-





                                 ARTICLE SEVEN

                HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

         Section 7.01.    Preservation of Information; Company To Furnish
                          Trustee Names and Addresses of Holders.

         (a)  The Trustee shall preserve the names and addresses of the
Noteholders and otherwise comply with TIA Section 312(a).  If the Trustee is
not the Registrar, the Company shall furnish or cause the Registrar to furnish
to the Trustee before each Interest Payment Date, and at such other times as
the Trustee may request in writing, a list in such form and as of such date as
the Trustee may reasonably require of the names and addresses of the
Noteholders.  Neither the Company nor the Trustee shall be under any
responsibility with regard to the accuracy of such list.

         (b)  The Company will furnish or cause to be furnished to the Trustee

         (i) semi-annually, not more than 15 days after each Regular Record
    Date, a list, in such form as the Trustee may reasonably require, of the
    names and addresses of the Holders as of such Regular Record Date; and

         (ii)    at such other times as the Trustee may reasonably request in
    writing, within 30 days after receipt by the Company of any such request, a
    list of similar form and content as of a date not more than 15 days prior
    to the time such list is furnished;

provided, however, that if and so long as the Trustee shall be the Registrar,
no such list need be furnished pursuant to this Subsection 7.01(b).

         Section 7.02.    Communications of Holders.

         Holders may communicate with other Holders with respect to their
rights under this Indenture or under the Notes pursuant to Section 312(b) of
the Trust Indenture Act.  The Company and the Trustee and any and all other
persons benefited by this Indenture shall have the protection afforded by
Section 312(c) of the Trust Indenture Act.
<PAGE>   85
                                      -77-

         Section 7.03.    Reports by Trustee.

         Within 60 days after May 15 of each year commencing with the first May
15 following the date of this Indenture, the Trustee shall mail to all Holders,
as their names and addresses appear in the Note Register, a brief report dated
as of such May 15, in accordance with, and to the extent required under Section
313 of the Trust Indenture Act.  At the time of its mailing to Holders, a copy
of each such report shall be filed by the Trustee with the Company, the SEC and
with each stock exchange on which the Notes are listed.  The Company shall
notify the Trustee when the Notes are listed on any stock exchange.

         Section 7.04.    Reports by Company.

         The Company shall:

         (a)  file with the SEC the copies of annual reports and of the
information, documents and other reports (or copies of such portions of any of
the foregoing as the SEC may from time to time by rules and regulations
prescribe) required to be filed with the SEC pursuant to Section 13 or Section
15 of the Exchange Act, whether or not the Company has a class of securities
registered under the Exchange Act;

         (b)  file with the Trustee within 15 days after it files or would be
required to file the information specified in subsection (a) of this Section
7.04 reports and documents with the SEC copies of such information;

         (c)  file with the Trustee and the SEC in accordance with rules and
regulations prescribed from time to time by the SEC, such additional
information, documents and reports with respect to compliance by the Company
with the conditions and covenants of this Indenture as may be required from
time to time by such rules and regulations; and

         (d)  transmit by mail to all Holders, as their names and addresses
appear in the Note Register, within 30 days after the filing thereof with the
Trustee, such summaries of any information, documents and reports required to
be filed by the Company pursuant to subsections (a) and (c) of this Section as
may be required by rules and regulations prescribed from time to time by the
SEC.

         Notwithstanding anything to the contrary herein, the Trustee shall
have no duty to review information provided pursuant
<PAGE>   86
                                      -78-

to subsection (b) of this Section 7.04 for purposes of determining compliance
with any provisions of this Indenture.


                                 ARTICLE EIGHT

                  CONSOLIDATION, MERGER, SALE OF ASSETS, ETC.

         Section 8.01.    Company May Consolidate, etc., Only on Certain Terms.

         The Company will not (i) consolidate or combine with or merge with or
into or, directly or indirectly, sell, assign, convey, lease, transfer or
otherwise dispose of all or substantially all of its properties and assets to
any person or persons in a single transaction or through a series of
transactions, or (ii) permit any of the Restricted Subsidiaries to enter into
any such transaction or series of transactions if it would result in the
disposition of all or substantially all of the properties or assets of the
Company and the Restricted Subsidiaries on a consolidated basis, unless, in the
case of either (i) or (ii), (a) the Company shall be the continuing person or,
if the Company is not the continuing person, the resulting, surviving or
transferee person (the "surviving entity") shall be a company organized and
existing under the laws of the United States or any State or territory thereof;
(b) the surviving entity shall expressly assume all of the obligations of the
Company under the Notes, and this Indenture, and shall, if required by law to
effectuate such assumption, execute a supplemental indenture to effect such
assumption, which supplemental indenture shall be delivered to the Trustee and
shall be in form and substance reasonably satisfactory to the Trustee; (c)
immediately after giving effect to such transaction or series of transactions
on a pro forma basis (including, without limitation, any Indebtedness incurred
or anticipated to be incurred in connection with or in respect of such
transaction or series of transactions), the Company or the surviving entity
(assuming such surviving entity's assumption of the Company's obligations under
the Notes and this Indenture), as the case may be, would be able to incur $1.00
of Indebtedness under the proviso of Section 10.11; provided that, in the case
of any transaction or series of transactions comprised solely of one or more
Rollups, this clause (c) shall be deemed satisfied if the Company or the
surviving entity and the Restricted Subsidiaries would have been able to incur
all of their outstanding Indebtedness as Permitted Indebtedness; (d)
immediately after giving effect to such transaction or series of transactions
on
<PAGE>   87
                                      -79-

a pro forma basis (including, without limitation, any Indebtedness incurred or
anticipated to be incurred in connection with or in respect of such transaction
or series of transactions), no Default shall have occurred and be continuing;
and (e) the Company or the surviving entity, as the case may be, shall have
delivered to the Trustee an Officers' Certificate stating that such transaction
or series of transactions, and, if a supplemental indenture is required in
connection with such transaction or series of transactions to effectuate such
assumption, such supplemental indenture, complies with this covenant and that
all conditions precedent in this Indenture relating to the transaction or
series of transactions have been satisfied.

         Section 8.02.    Successor Substituted.

         Upon any consolidation or merger or any sale, assignment, conveyance,
lease, transfer or other disposition of all or substantially all of the assets
of the Company in accordance with the foregoing in which the Company or the
Restricted Subsidiary, as the case may be, is not the continuing corporation,
the successor corporation formed by such a consolidation or into which the
Company or such Restricted Subsidiary is merged or to which such transfer is
made will succeed to, and be substituted for, and may exercise every right and
power of, the Company or such Restricted Subsidiary, as the case may be, under
this Indenture, and the Notes with the same effect as if such successor
corporation had been named as the Company or such Restricted Subsidiary
therein; and thereafter, except in the case of (i) any lease or (ii) any sale,
assignment, conveyance, transfer, lease or other disposition to a Restricted
Subsidiary of the Company, the Company shall be discharged from all obligations
and covenants under this Indenture and the Notes.

         For all purposes of this Indenture and the Notes (including the
provision of this Article Eight and Sections 10.11, Section 10.13 and Section
10.16), Subsidiaries of any surviving entity will, upon such transaction or
series of related transactions, become Restricted Subsidiaries or Unrestricted
Subsidiaries as provided pursuant to Section 10.21 and all Indebtedness, and
all Liens on property or assets, of the Company and the Restricted Subsidiaries
in existence immediately prior to such transaction or series of related
transactions will be deemed to have been incurred upon such transaction or
series of related transactions.
<PAGE>   88
                                      -80-




                                  ARTICLE NINE

                      SUPPLEMENTAL INDENTURES AND WAIVERS

         Section 9.01.    Supplemental Indentures, Agreements and Waivers
                          Without Consent of Holders.

         Without the consent of any Holders, the Company, and  when authorized
by a Board Resolution of the Board, and the Trustee, at any time and from time
to time, may amend, waive, modify or supplement this Indenture or the Notes for
any of the following purposes:

         (a)  to evidence the succession of another person to the Company, and
the assumption by any such successor of the covenants of the Company in the
Notes;

         (b)  to add to the covenants of the Company for the benefit of the
Holders, or to surrender any right or power herein conferred upon the Company,
herein, in the Notes;

         (c)  to cure any ambiguity, to correct or supplement any provision
herein, in the Notes which may be defective or inconsistent with any other
provision herein or to make any other provisions with respect to matters or
questions arising under this Indenture or the Notes; provided, however, that,
in each case, such provisions shall not materially adversely affect the legal
rights of any Holder;

         (d)  to comply with the requirements of the SEC in order to effect or
maintain the qualification of this Indenture under the Trust Indenture Act, as
contemplated by Section 9.05 hereof or otherwise;

         (e)  to evidence and provide the acceptance of the appointment of a
successor Trustee hereunder;

         (f)  to mortgage, pledge, hypothecate or grant a security interest in
any property or assets in favor of the Trustee for the benefit of the Holders
as security for the payment and performance of Indenture Obligations; or

         (g)  to make any other change that does not materially adversely
affect the legal rights of any Holder;
<PAGE>   89
                                      -81-

provided, however, that the Company has delivered to the Trustee an Opinion of
Counsel stating that such change, agreement or waiver does not materially
adversely affect the legal rights of any Holder.

         Section 9.02.    Supplemental Indentures, Agreements and Waivers with
                          Consent of Holders.

         With the written consent of the Holders of not less than a majority in
aggregate principal amount of the Outstanding Notes delivered to the Company
and the Trustee, the Company when authorized by a Board Resolution, together
with the Trustee, may amend, waive, modify or supplement any other provision of
this Indenture or the Notes; provided, however, that no such amendment, waiver,
modification or supplement may, without the written consent of the Holder of
each Outstanding Note affected thereby:

         (i)     reduce the principal amount of, change the fixed maturity of,
    or alter the redemption provisions of, the Notes,

         (ii)    change the currency in which any Notes or amounts owing
    thereon is payable,

         (iii)   reduce the percentage of the aggregate principal amount
    Outstanding of Notes which must consent to an amendment, supplement or
    waiver or consent to take any action under this Indenture or the Notes,

         (iv)    impair the right to institute suit for the enforcement of any
    payment on or with respect to the Notes,

         (v)     waive a default in payment with respect to the Notes,

         (vi)    reduce the rate or change the time for payment of interest on
    the Notes,

         (vii)   following the occurrence of a Change of Control or an Asset
    Sale, alter the Company's obligation to purchase the Notes in accordance
    with this Indenture or waive any default in the performance thereof,

         (viii)  affect the ranking of the Notes in a manner adverse to the
    holder of the Notes, or
<PAGE>   90
                                      -82-

         (ix)    release any Guarantee except in compliance with the terms of
    the Indenture.

         Upon the written request of the Company accompanied by a copy of a
Board Resolution of the Board authorizing the execution of any such
supplemental indenture or other agreement, instrument or waiver, and upon the
filing with the Trustee of evidence of the consent of Holders as aforesaid, the
Trustee shall join with the Company in the execution of such supplemental
indenture or other agreement, instrument or waiver.

         It shall not be necessary for any Act of Holders under this Section to
approve the particular form of any proposed supplemental indenture or other
agreement, instrument or waiver, but it shall be sufficient if such Act shall
approve the substance thereof.

         Section 9.03.    Execution of Supplemental Indentures, Agreements and
                          Waivers.

         In executing, or accepting the additional trusts created by, any
supplemental indenture, agreement, instrument or waiver permitted by this
Article Nine or the modifications thereby of the trusts created by this
Indenture, the Trustee shall be entitled to receive, and (subject to Section
6.01 hereof) shall be fully protected in relying upon, an Opinion of Counsel
and an Officers' Certificate from each obligor under the Notes entering into
such supplemental indenture, agreement, instrument or waiver, each stating that
the execution of such supplemental indenture, agreement, instrument or waiver
(a) is authorized or permitted by this Indenture and (b) does not violate the
provisions of any agreement or instrument evidencing any other Indebtedness of
the Company or any other Subsidiary of the Company.  The Trustee may, but shall
not be obligated to, enter into any such supplemental indenture, agreement,
instrument or waiver which affects the Trustee's own rights, duties or
immunities under this Indenture, the Notes or otherwise.

         Section 9.04.    Effect of Supplemental Indentures.

         Upon the execution of any supplemental indenture under this Article
Nine, this Indenture and/or the Notes, if applicable, shall be modified in
accordance therewith, and such supplemental indenture shall form a part of this
Indenture and/or the Notes, if applicable, as the case may be, for all
<PAGE>   91
                                      -83-

purposes; and every Holder of Notes theretofore or thereafter authenticated and
delivered hereunder shall be bound thereby.

         Section 9.05.    Conformity with Trust Indenture Act.

         Every supplemental indenture executed pursuant to this Article Nine
shall conform to the requirements of the Trust Indenture Act as then in effect.

         Section 9.06.    Reference in Notes to

         Supplemental Indentures.

         Notes authenticated and delivered after the execution of any
supplemental indenture pursuant to this Article may, and shall if required by
the Trustee, bear a notation in form approved by the Trustee as to any matter
provided for in such supplemental indenture.  If the Company shall so
determine, new Notes so modified as to conform, in the opinion of the Trustee
and the Board, to any such supplemental indenture may be prepared and executed
by the Company and authenticated and delivered by the Trustee upon a Company
Order in exchange for Outstanding Notes.

         Section 9.07.    Record Date.

         The Company may, but shall not be obligated to, fix, a record date for
the purpose of determining the Holders entitled to consent to any supplemental
indenture, agreement or instrument or any waiver, and shall promptly notify the
Trustee of any such record date.  If a record date is fixed, those persons who
were Holders at such record date (or their duly designated proxies), and only
those persons, shall be entitled to consent to such supplemental indenture,
agreement or instrument or waiver or to revoke any consent previously given,
whether or not such persons continue to be Holders after such record date.  No
such consent shall be valid or effective for more than 90 days after such
record date.

         Section 9.08.    Revocation and Effect of Consents.

         Until an amendment or waiver becomes effective, a consent to it by a
Holder of a Note is a continuing consent by the Holder and every subsequent
Holder of a Note or portion of a Note that evidences the same debt as the
consenting Holder's Note, even if a notation of the consent is not made on any
Note.  However, any such Holder, or subsequent Holder, may revoke the consent
as to his Note or portion of a Note if the Trustee receives the notice of
revocation  before the date the
<PAGE>   92
                                      -84-

amendment or waiver becomes effective.  An amendment or waiver shall become
effective in accordance with its terms and thereafter bind every Holder.


                                  ARTICLE TEN

                                   COVENANTS

         Section 10.01.   Payment of Principal, Premium and Interest.

         The Company will duly and punctually pay the principal of, premium, if
any, and interest on the Notes in accordance with the terms of the Notes and
this Indenture.

         Section 10.02.   Maintenance of Office or Agency.

         The Company will maintain in the Borough of Manhattan in The City of
New York, State of New York, an office or agency where Notes may be presented
or surrendered for payment, where Notes may be surrendered for registration of
transfer or exchange and where notices and demands to or upon the Company in
respect of the Notes and this Indenture may be served.  The office of the
Trustee at its Corporate Trust Office will be such office or agency of the
Company, unless the Company shall designate and maintain some other office or
agency for one or more of such purposes.  The Company will give prompt written
notice to the Trustee of any change in the location of any such office or
agency.  If at any time the Company shall fail to maintain any such required
office or agency or shall fail to furnish the Trustee with the address thereof,
such presentations, surrenders, notices and demands may be made or served at
the Corporate Trust Office of the Trustee, and the Company hereby appoints the
Trustee as its agent to receive all such presentations, surrenders, notices and
demands.

         The Company may also from time to time designate one or more other
offices or agencies (in or outside of The City of New York, State of New York)
where the Notes may be presented or surrendered for any or all such purposes,
and may from time to time rescind such designation; provided, however, that no
such designation or rescission shall in any manner relieve the Company of its
obligation to maintain an office or agency in The City of New York, State of
New York for such purposes.  The Company will give prompt written notice to the
Trustee of any
<PAGE>   93
                                      -85-

such designation or rescission and any change in the location of any such other
office or agency.

         Section 10.03.   Money for Note Payments To Be Held in Trust.

         If the Company shall at any time act as its own Paying Agent, it will,
on or before each due date of the principal of, premium, if any, or interest on
any of the Notes, segregate and hold in trust for the benefit of the Holders
entitled thereto a sum sufficient to pay the principal, premium, if any, or
interest so becoming due until such sums shall be paid to such persons or
otherwise disposed of as herein provided, and will promptly notify the Trustee
of its action or failure so to act.

         If the Company is not acting as Paying Agent, the Company will, on or
before each due date of the principal of, premium, if any, or interest on, any
Notes, deposit with a Paying Agent a sum in same day funds sufficient to pay
the principal, premium, if any, or interest so becoming due, such sum to be
held in trust for the benefit of the Holders entitled to such principal,
premium or interest, and (unless such Paying Agent is the Trustee) the Company
will promptly notify the Trustee of such action or any failure so to act.

         If the Company is not acting as Paying Agent, the Company will cause
each Paying Agent other than the Trustee to execute and deliver to the Trustee
an instrument in which such Paying Agent will agree with the Trustee, subject
to the provisions of this Section 10.03, that such Paying Agent will:

         (a)  hold all sums held by it for the payment of the principal of,
premium, if any, or interest on Notes in trust for the benefit of the Holders
entitled thereto until such sums shall be paid to such Holders or otherwise
disposed of as herein provided;

         (b)  give the Trustee notice of any Default by the Company (or any
other obligor upon the Notes) in the making of any payment of principal of,
premium, if any, or interest on the Notes;

         (c)  at any time during the continuance of any such Default, upon the
written request of the Trustee, forthwith pay to the Trustee all sums so held
in trust by such Paying Agent; and
<PAGE>   94
                                      -86-

         (d)  acknowledge, accept and agree to comply in all aspects with the
provisions of this Indenture relating to the duties, rights and liabilities of
such Paying Agent.

         The Company may at any time, for the purpose of obtaining the
satisfaction and discharge of this Indenture or for any other purpose, pay, or
by Company Order direct any Paying Agent to pay, to the Trustee all sums held
in trust by the Company or such Paying Agent, such sums to be held by the
Trustee upon the same trusts as those upon which such sums were held by the
Company or such Paying Agent; and, upon such payment by any Paying Agent to the
Trustee, such Paying Agent will be released from all further liability with
respect to such money.

         Any money deposited with the Trustee or any Paying Agent, or then held
by the Company, in trust for the payment of the principal of, premium, if any,
or interest on any Note and remaining unclaimed for two years after such
principal, premium, if any, or interest has become due and payable shall be
paid to the Company upon receipt of a Company Request therefor, or (if then
held by the Company) will be discharged from such trust; and the Holder of such
Note will thereafter, as an unsecured general creditor, look only to the
Company for payment thereof, and all liability of the Trustee or such Paying
Agent with respect to such trust money, and all liability of the Company as
trustee thereof, will thereupon cease; provided, however, that the Trustee or
such Paying Agent, before being required to make any such repayment, may at the
expense of the Company cause to be published once, at the option of the Company
in the New York Times or the Wall Street Journal (national edition), notice
that such money remains unclaimed and that, after a date specified therein,
which shall not be less than 30 days from the date of such publication, any
unclaimed balance of such money then remaining shall be repaid to the Company.

         Section 10.04.   Corporate Existence.

         Subject to Article Eight, the Company will do or cause to be done all
things necessary to preserve and keep in full force and effect the corporate
existence, rights (charter and statutory), licenses and franchises of the
Company and each of the Restricted Subsidiaries; provided, however, that the
Company will not be required to preserve any such right, license or franchise
if the Board shall determine that the preservation thereof is no longer
desirable in the conduct of the business of the Company and the  Restricted
Subsidiaries as a whole and that the loss thereof is not adverse in any
material respect to the Holders; provided, further, that the foregoing
<PAGE>   95
                                      -87-

will not prohibit a sale, transfer or conveyance of a Subsidiary of the Company
or any of its assets in compliance with the terms of this Indenture.

         Section 10.05.   Payment of Taxes and Other Claims.

         The Company will pay or discharge or cause to be paid  or discharged,
before the same shall become delinquent, (a) all material taxes, assessments
and governmental charges levied or imposed (i) upon the Company or any of its
Restricted Subsidiaries or (ii) upon the income, profits or property of the
Company or any of the Restricted Subsidiaries and (b) all material lawful
claims for labor, materials and supplies, which, if unpaid, could reasonably be
expected to become a Lien upon the property of the Company or any of the
Restricted Subsidiaries; provided, however, that the Company will not be
required to pay or discharge or cause to be paid or discharged any such tax,
assessment, charge or claim (x) whose amount, applicability or validity is
being contested in good faith by appropriate proceedings properly instituted
and diligently conducted or (y) if the failure to so pay, discharge or cause to
be paid or discharged could not reasonably be expected to have a Material
Adverse Effect (as defined in the Purchase Agreement).

         Section 10.06.   Maintenance of Properties.

         The Company will cause all material properties owned by the Company or
any of the Restricted Subsidiaries or used or held for use in the conduct of
their respective businesses to be maintained and kept in good condition, repair
and working order and supplied with all necessary equipment and will cause to
be made all necessary repairs, renewals, replacements, betterments and
improvements thereof, all as in the judgment of the Company may be necessary so
that the business carried on in connection therewith may be properly and
advantageously conducted at all times; provided, however, that nothing in this
Section 10.06 will prevent the Company from discontinuing the maintenance of
any of such properties if such discontinuance is, in the judgment of the
Company, desirable in the conduct of its business or the business of any of the
Restricted Subsidiaries and is not adverse in any material respect to the
Holders.

         Section 10.07.   Insurance.

         The Company will at all times keep all of its and the Restricted
Subsidiaries' properties which are of an insurable nature insured with
insurers, believed by the Company in good
<PAGE>   96
                                      -88-

faith to be financially sound and responsible, against loss or damage to the
extent that property of similar character is usually and customarily so insured
by corporations similarly situated and owning like properties.

         Section 10.08.   Books and Records.

         The Company will keep proper books of record and account, in which
full and correct entries will be made of all financial transactions and the
assets and business of the Company and each Restricted Subsidiary of the
Company in material compliance with GAAP.

         Section 10.09.   Provision of Financial Statements.

         Subject to Section 10.23, the Company will file with the SEC (so long
as the SEC will accept any such filings) the Trustee and the Initial Purchasers
the annual reports, quarterly reports and other documents required to be filed
with the SEC pursuant to Sections 13 and 15 of the Exchange Act, whether or not
the Company has a class of securities registered under the Exchange Act.  The
Company will also comply with the other provisions of Section 314(a) of the
Trust Indenture Act.

         Section 10.10.   Change of Control.

         Upon the occurrence of a Change of Control (the date of such
occurrence being the "Change of Control Date"), the Company shall make an offer
to purchase (the "Change of Control Offer"), on a Business Day (the "Change of
Control Payment Date") not later than 60 days following the Change of Control
Date, all Notes then Outstanding at a purchase price equal to 101% of the
principal amount thereof on any Change of Control Payment Date, plus accrued
and unpaid interest, if any, to such Change of Control Payment Date.  Notice of
a Change of Control Offer shall be given to holders of Notes not less than 25
days nor more than 45 days before the Change of Control Payment Date.  The
Change of Control Offer is required to remain open for at least 20 Business
Days.  Failure to mail the notice of a Change of Control Offer on the date
specified below or to have satisfied the foregoing condition precedent by the
date that such notice is required to be mailed will constitute a covenant
Default under Section 5.01(iii).

         Notice of a Change of Control Offer shall be mailed by the Company not
more than 20 Business Days after the Change of Control Date to the Holders of
Notes at their last registered addresses with a copy to the Trustee and the
Paying
<PAGE>   97
                                      -89-

Agent.  The Change of Control Offer shall remain open from the time of mailing
for at least 20 Business Days and until 5:00 p.m., New York City time, on the
Change of Control Payment Date.  The notice, which shall govern the terms of
the Change of Control Offer, shall include such disclosures as are required by
law and shall state:

         (a)  that the Change of Control Offer is being made pursuant to this
Section 10.10 and that all Notes tendered into the Change of Control Offer will
be accepted for payment;

         (b)  the purchase price (including the amount of accrued interest, if
any) for each Note, the Change of Control Payment Date and the date on which
the Change of Control Offer expires;

         (c)  that any Note not tendered for payment will continue to accrue
interest in accordance with the terms thereof;

         (d)  that, unless the Company shall default in the payment of the
purchase price, any Note accepted for payment pursuant to the Change of Control
Offer shall cease to accrue interest after the Change of Control Payment Date;

         (e)  that Holders electing to have Notes purchased pursuant to a
Change of Control Offer will be required to surrender their Notes to the Paying
Agent at the address specified in the notice prior to 5:00 p.m., New York City
time, on the Change of Control Payment Date and must complete any form letter
of transmittal proposed by the Company and acceptable to the Trustee and the
Paying Agent;

         (f)  that Holders of Notes will be entitled to withdraw their election
if the Paying Agent receives, not later than 5:00 p.m., New York City time, on
the Change of Control Payment Date, a facsimile transmission or letter setting
forth the name of the Holders, the principal amount of Notes the Holders
delivered for purchase, the Note certificate number (if any) and a statement
that such Holder is withdrawing his election to have such Notes purchased;

         (g)  that Holders whose Notes are purchased only in part will be
issued Notes of like tenor equal in principal amount to the unpurchased portion
of the Notes surrendered;

         (h)  the instructions that Holders must follow in order to tender
their Notes; and
<PAGE>   98
                                      -90-

         (i)  information concerning the business of the Company, the most
recent annual and quarterly reports of the Company filed with the SEC pursuant
to the Exchange Act (or, if the Company is not required to file any such
reports with the SEC, the comparable reports prepared pursuant to Section
10.09), a description of material developments in the Company's business,
information with respect to pro forma historical financial information after
giving effect to such Change of Control and such other information concerning
the circumstances and relevant facts regarding such Change of Control and
Change of Control Offer as would, in the good faith judgment of the Company, be
material to a Holder of Notes in connection with the decision of such Holder as
to whether or not it should tender Notes pursuant to the Change of Control
Offer.

         On the Change of Control Payment Date, the Company will (i) accept for
payment Notes or portions thereof tendered pursuant to the Change of Control
Offer, (ii) deposit with the Paying Agent money, in immediately available
funds, sufficient to pay the purchase price of all Notes or portions thereof so
tendered and accepted and (iii) deliver to the Trustee the Notes so accepted
together with an Officers' Certificate setting forth the Notes or portions
thereof tendered to and accepted for payment by the Company.  The Paying Agent
will promptly mail or deliver to the Holders of Notes so accepted payment in an
amount equal to the purchase price, and the Trustee shall promptly authenticate
and mail or deliver to such Holders a new Note of like tenor equal in principal
amount to any unpurchased portion of the Note surrendered.  Any Notes not so
accepted shall be promptly mailed or delivered by the Company to the Holder
thereof.  The Company will publicly announce the results of the Change of
Control Offer not later than the first Business Day following the Change of
Control Payment Date.  Except as described above with respect to a Change of
Control, this Indenture does not contain provisions that permit the holders of
the Notes to require that the Company repurchase or redeem the Notes in the
event of a takeover, recapitalization or similar transaction which may be
highly leveraged.  If a Change of Control Offer is made, there can be no
assurance that the Company will have available funds sufficient to pay for all
of the Notes that might be delivered by holders of Notes seeking to accept the
Change of Control Offer.  The Company shall not be required to make a Change of
Control Offer following a Change of Control if a third party makes the Change
of Control Offer in the manner, at the times and otherwise in compliance with
the requirements applicable to a Change of Control Offer made by the Company
and purchases all Notes validly tendered and not withdrawn under such Change of
Control Offer.
<PAGE>   99
                                      -91-

         If the Company is required to make a Change of Control Offer, the
Company will comply with all applicable tender offer laws and regulations,
including, to the extent applicable, Section 14(e) and Rule 14e-1 under the
Exchange Act, and any other applicable securities laws and regulations.  To the
extent that the provisions of any securities laws or regulations conflict with
the provisions of this Section 10.10, the Company will comply with the
applicable securities laws and regulations and shall not be deemed to have
breached its obligations under this Section 10.10 by virtue thereof.

         Section 10.11.   Limitation on Additional Indebtedness.

         The Company will not, and will not permit any Restricted Subsidiary
to, directly or indirectly, incur, any Indebtedness (including any Acquired
Indebtedness), except for Permitted Indebtedness (including Acquired
Indebtedness to the extent it would constitute Permitted Indebtedness);
provided, however, that (i) the Company will be permitted to incur Indebtedness
(including Acquired Indebtedness) and (ii) a Restricted Subsidiary will be
permitted to incur Acquired Indebtedness, if, in either case, immediately after
giving pro forma effect to such incurrence (including the application of the
net proceeds therefrom), the ratio of Total Consolidated Indebtedness to
Consolidated Annualized Pro Forma Operating Cash Flow would be less than 6.0 to
1.0.

         For purposes of determining compliance with this Section 10.11, in the
event that an item of Indebtedness meets the criteria of more than one of the
types of Indebtedness permitted by this covenant, the Company in its sole
discretion shall classify such item of Indebtedness and only be required to
include the amount of such Indebtedness as one of such types.

         Section 10.12.   Statement by Officers as to Default.

         The Company will deliver to the Trustee, within 120 days after the end
of each fiscal year of the Company ending after the date hereof, a written
statement signed by the chairman or a chief executive officer, the principal
financial officer or principal accounting officer of the Company, stating (i)
that a review of the activities of the Company during the preceding fiscal year
has been made under the supervision of the signing officers with a view to
determining whether the Company has kept,
<PAGE>   100
                                      -92-

observed, performed and fulfilled its obligations under this Indenture, and
(ii) that, to the knowledge of each officer signing such certificate, the
Company has kept, observed, performed and fulfilled each and every covenant and
condition contained in this Indenture and is not in default in  the performance
or observance of any of the terms, provisions, conditions and covenants hereof
(or, if a Default shall have occurred, describing all such Defaults of which
such officers may have knowledge, their status and what action the Company is
taking or proposes to take with respect thereto).  When any Default under this
Indenture has occurred and is continuing, or if the Trustee or any Holder or
the trustee for or the holder of any other evidence of Indebtedness of the
Company or any Restricted Subsidiary gives any notice or takes any other action
with respect to a claimed default (other than with respect to Indebtedness
(other than Indebtedness evidenced by the Notes) in the principal amount of
less than $7,500,000), the Company will promptly notify the Trustee of such
Default, notice or action and will deliver to the Trustee by registered or
certified mail or by telegram, or facsimile transmission followed by hard copy
by registered or certified mail an Officers' Certificate specifying such event,
notice or other action within five Business Days after the Company becomes
aware of such occurrence and what action the Company is taking or proposes to
take with respect thereto.

         Section 10.13.   Limitation on Restricted Payments.

         The Company will not, and will not permit any of the Restricted
Subsidiaries to, make, directly or indirectly, any Restricted Payment unless:

         (i)     no Default shall have occurred and be continuing at the time
    of or upon giving effect to such Restricted Payment;

         (ii)    immediately after giving effect to such Restricted Payment,
    the Company would be able to incur $1.00 of Indebtedness under the proviso
    of Section 10.11 hereof; and

         (iii)   immediately after giving effect to such Restricted Payment,
    the aggregate amount of all Restricted Payments declared or made on or
    after the Issue Date and all Designation Amounts does not exceed an amount
    equal to the sum of, without duplication, (a) 50% of the Consolidated Net
    Income of the Company accrued on a cumulative basis during the period
    beginning on January 1, 1998 and ending on the last day of the fiscal
    quarter of the Company immediately preceding the date of such proposed
    Restricted Payment (or, if such cumulative Consolidated Net
<PAGE>   101
                                      -93-

    Income of the Company for such period is a deficit, minus 100% of such
    deficit), plus (b) the aggregate net cash proceeds received by the Company
    either (x) as capital contributions to the Company after the Issue Date or
    (y) from the issue and sale (other than to a Restricted Subsidiary of the
    Company) of its Capital Stock (other than Disqualified Stock) on or after
    the Issue Date (including upon exercise of warrants, options or rights),
    plus (c) the aggregate net proceeds received by the Company from the
    issuance (other than to a Restricted Subsidiary of the Company) on or after
    the Issue Date of its Capital Stock (other than Disqualified Stock) upon
    the conversion of, or in exchange for, Indebtedness of the Company, plus
    (d) in the case of the disposition or repayment (in whole or in part) of
    any Investment constituting a Restricted Payment made after the Issue Date
    (except for Investments made (1) pursuant to clause (vii) of the second
    following paragraph that are not subject to clause (e) or (f) of this
    paragraph below, and (2) pursuant to clauses (viii) or (ix) of the second
    following paragraph), an amount equal to the lesser of the return of
    capital with respect to the applicable portion of such Investment and the
    cost of the applicable portion of such Investment, in either case, less the
    cost of the disposition of such Investment, plus (e) in the case of any
    Revocation with respect to a Subsidiary of the Company that was made
    subject to a Designation after the Issue Date, an amount equal to the
    lesser of the Designation Amount with respect to such Subsidiary or the
    Fair Market Value of the Investment of the Company and the Restricted
    Subsidiaries in such Subsidiary at the time of Revocation, plus (f) an
    amount equal to the amount of any Investment constituting a Restricted
    Payment made after the Issue Date in an ISP which has been included as a
    Restricted Payment under this clause (iii) pursuant to the last paragraph
    of this Section 10.13 to the extent such ISP thereafter (1) becomes a
    Wholly Owned Restricted Subsidiary or is merged with the Company or (2) is
    a New ISP that becomes a Restricted Subsidiary or is merged with the
    Company, less, in either such case, any amounts credited pursuant to the
    preceding clause (d) in respect of any such Investment, minus (g) 50% of
    the principal amount of any Indebtedness incurred pursuant to clause (g) of
    the definition of "Permitted Indebtedness." For purposes of the preceding
    clauses (b)(y) and (c), as applicable, the value of the aggregate net
    proceeds received by the Company upon the issuance of Capital Stock either
    upon the conversion of convertible Indebtedness or in exchange for
<PAGE>   102
                                      -94-

    outstanding Indebtedness or upon the exercise of options, warrants or
    rights will be the net cash proceeds received upon the issuance of such
    Indebtedness, options, warrants or rights plus the incremental amount
    received, if any, by the Company upon the conversion, exchange or exercise
    thereof.

         For purposes of determining the amount expended for Restricted
Payments, cash distributed shall be valued at the face amount thereof and
property other than cash shall be valued at its Fair Market Value.

         The provisions of this Section 10.13 shall not prohibit the following
(each of which shall be given independent effect):

         (i)     the payment of any dividend or other distribution within 60
    days after the date of declaration thereof if at such date of declaration
    such payment would be permitted by the provisions of the Indenture;

         (ii)    the purchase, redemption, retirement or other acquisition of
    any shares of Capital Stock of the Company in exchange for, or out of the
    net cash proceeds of the substantially concurrent issue and sale (other
    than to a Restricted Subsidiary of the Company) of, shares of Capital Stock
    of the Company (other than Disqualified Stock); provided that any such net
    cash proceeds are excluded from clause (iii)(b) of the second preceding
    paragraph;

         (iii)   so long as no Default shall have occurred and be continuing,
    the purchase, redemption, retirement, defeasance or other acquisition of
    Subordinated Indebtedness made by exchange for, or out of the net cash
    proceeds of, a substantially concurrent issue and sale (other than to a
    Restricted Subsidiary of the Company) of (x) Capital Stock (other than
    Disqualified Stock) of the Company or (y) other Subordinated Indebtedness
    to the extent that its stated maturity for the payment of principal thereof
    is not prior to the 180th day after the final stated maturity of the Notes;
    provided that any such net cash proceeds are excluded from clause (iii)(b)
    of the second preceding paragraph;

         (iv)    (a) so long as no Default shall have occurred and be
    continuing, Investments constituting Restricted Payments by the Company or
    any Restricted Subsidiary in a New ISP or a person that becomes a New ISP
    as a result of
<PAGE>   103
                                      -95-

    such Investment and (b) so long as no Default shall have occurred and be
    continuing, Investments constituting Restricted Payments by the Company or
    any Restricted Subsidiary in an Existing ISP (x) made out of the net cash
    proceeds of a substantially concurrent sale of Capital Stock (other than
    Disqualified Stock) of the Company (provided that any such proceeds are
    excluded from clause (iii)(b) of the second preceding paragraph) or (y)
    such that the aggregate amount of all Investments in Existing ISPs that are
    made after the Issue Date pursuant to this subclause (b)(y) would not
    exceed $25.0 million in aggregate;

         (v)     bonds, notes, debentures or other securities received as a 
    result of Asset Sales pursuant to and in compliance with Section 10.15 
    hereof;

         (vi)    so long as no Default shall have occurred and be continuing,
    purchases or redemptions of Capital Stock (including cash settlements of
    stock options) held by employees, officers or directors upon or following
    termination of their employment with the Company or one of its
    Subsidiaries; provided that payments shall not exceed $2.0 million in any
    fiscal year in the aggregate or $4.0 million in the aggregate during the
    term of the Notes;

         (vii)   so long as no Default shall have occurred and be continuing,
    Investments in Unrestricted Subsidiaries to the extent reasonably promptly
    made with the proceeds of a substantially concurrent (1) capital
    contribution to the Company or (2) issue or sale of Capital Stock (other
    than Disqualified Stock) of the Company (other than to a Restricted
    Subsidiary of the Company); provided that any such proceeds are excluded
    from clause (iii)(b) of the second preceding paragraph;

         (viii)  loans or advances to employees of the Company or any
    Restricted Subsidiary made in the ordinary course of business, including to
    fund the purchase of Capital Stock of the Company (provided that any
    proceeds from such purchase are excluded from clause (iii)(b) of the second
    preceding paragraph to the extent such loan or advance is not reimbursed)
    in an amount not to exceed $2.0 million at any time outstanding;

         (ix)    so long as no Default shall have occurred and be continuing,
    Investments constituting Restricted Payments in joint ventures formed to
    provide services in furtherance
<PAGE>   104
                                      -96-

    of an Internet Service Business of the Company and the ISPs or other
    persons engaged principally in an Internet Service Business in an aggregate
    amount not to exceed $30.0 million outstanding at any time; provided that
    following the first Public Equity Offering resulting in aggregate gross
    cash proceeds of $50.0 million or more to the Company, the aggregate amount
    of Investments permitted pursuant to this clause (ix) shall be increased to
    an aggregate amount not to exceed $50.0 million outstanding at any time;
    and

         (x) cash payments in lieu of fractional shares pursuant to any
    warrant, option or other similar agreement.

         In determining whether the receipt of net cash proceeds of a sale of
Capital Stock is "substantially concurrent" for purposes of clause (iv)(b)(x)
of the preceding paragraph, if such net cash proceeds are deposited in escrow
with a third party, free and clear of any Lien (other than the Lien of the
escrow agent), to be applied for purposes directed by the Company and such net
cash proceeds are excluded from clause (iii)(b) of the first paragraph above,
then the application of such net cash proceeds as set forth in such clause
(iv)(b)(x) shall be deemed "substantially concurrent" if they are subsequently
released for immediate application as contemplated by such clause (iv)(b)(x).
In no event shall a Restricted Payment made on the basis of consolidated
financial statements prepared in good faith in accordance with GAAP be subject
to rescission or constitute a Default by reason of any requisite subsequent
restatement of such financial statements which would have made such Restricted
Payment prohibited at the time that it was made.

         In determining the amount of Restricted Payments permissible under
this Section 10.13, amounts expended pursuant to clauses (i), (iv)(a),
(iv)(b)(y), (v), (vi) and (ix) (to the extent remaining outstanding) above
shall be included, without duplication, as Restricted Payments.

         Section 10.14.   Limitation on Transactions with Affiliates.

         The Company will not, and will not permit, cause or suffer any
Restricted Subsidiary to, conduct any business or enter into any transaction
(or series of related transactions which are similar or part of a common plan)
with or for the benefit of any of their respective Affiliates (other than
Affiliates that are not also Affiliates of the Company or any
<PAGE>   105
                                      -97-

Wholly Owned Restricted Subsidiary) or any beneficial holder of 10% or more of
the Common Stock of the Company or any officer or director of the Company
(each, an "Affiliate Transaction"), unless the terms of the Affiliate
Transaction are set forth in writing, and are fair and reasonable to the
Company or such Restricted Subsidiary, as the case may be.  Each Affiliate
Transaction involving aggregate payments or other Fair Market Value in excess
of $1.0 million shall be approved by a majority of the Board, such approval to
be evidenced by a Board Resolution stating that the Board has determined that
such transaction or transactions comply with the foregoing provisions.  In
addition to the foregoing, each Affiliate Transaction involving aggregate
consideration of $5.0 million or more shall be approved by a majority of the
Disinterested Directors; provided that, in lieu of such approval by the
Disinterested Directors, the Company may obtain a written opinion from an
Independent Financial Advisor stating that the terms of such Affiliate
Transaction to the Company or the Restricted Subsidiary, as the case may be,
are fair from a financial point of view.  For purposes of this Section 10.14,
any Affiliate Transaction approved by a majority of the Disinterested Directors
or as to which a written opinion has been obtained from an Independent
Financial Advisor, on the basis set forth in the preceding sentence, shall be
deemed to be on terms that are fair and reasonable to the Company or the
Restricted Subsidiaries, as the case may be, and, therefore, shall be permitted
under this Section 10.14.

         Notwithstanding the foregoing, the restrictions set forth in this
Section 10.14 shall not apply to (i) transactions with or among, or solely for
the benefit of, the Company and/or any of the Restricted Subsidiaries, (ii)
transactions pursuant to agreements and arrangements existing on the Issue
Date, (iii) transactions related to the provision of internet services in the
ordinary course of business; provided that (x) such transactions are entered
into on an arm's length basis and are fair and reasonable to the Company or
such Restricted Subsidiary, as the case may be, and (y) in the good faith
judgment of the Company or the applicable Restricted Subsidiary, the Fair
Market Value of the consideration received by the Company or such Restricted
Subsidiary, as the case may be, reasonably approximates the Fair Market Value
of the services provided, (iv) dividends paid by the Company pursuant to and in
compliance with Section 10.13 hereof, (v) customary directors' fees,
indemnification and similar arrangements, consulting fees, employee salaries,
bonuses, employment agreements and arrangements, compensation or employee
benefit arrangements or legal fees, (vi) transactions contemplated by any of
the Permitted Affiliate Agreements as in effect on the Issue Date and (vii)
<PAGE>   106
                                      -98-

grants of customary registration rights with respect to securities of the
Company.

         The Company shall use, and shall cause each Restricted Subsidiary to
use, its commercially reasonable best efforts to ensure that each person in
which the Company or a Restricted Subsidiary makes an Investment that is an ISP
at the time of the Investment continues to meet the conditions and requirements
of the definition of "ISP" in all material respects until such time as a Rollup
shall have occurred with respect to such ISP.

         Section 10.15.   Disposition of Proceeds of Asset Sales

         The Company will not, and will not permit any Restricted Subsidiary
to, make any Asset Sale unless (a) the Company or such Restricted Subsidiary,
as the case may be, receives consideration at the time of such Asset Sale at
least equal to the Fair Market Value of the shares or assets sold or otherwise
disposed of and (b) at least 75% of such consideration consists of cash or Cash
Equivalents; provided that the following shall be treated as cash for purposes
of this Section 10.15:  (x) the amount of any liabilities (other than
Subordinated Indebtedness or Indebtedness of a Restricted Subsidiary that would
not constitute Restricted Subsidiary Indebtedness) that are assumed by the
transferee of any such assets pursuant to an agreement that unconditionally
releases the Company or such Restricted Subsidiary from further liability
("assumed liabilities") and (y) the amount of any notes or other obligations
that within 30 days of receipt, are converted into cash (to the extent of the
cash received).  The Company or the applicable Restricted Subsidiary, as the
case may be, may (i) apply the Net Cash Proceeds from such Asset Sale within
365 days of the receipt thereof to repay an amount of Indebtedness (other than
Subordinated Indebtedness) of the Company in an amount not exceeding the Other
Senior Debt Pro Rata Share and elect to permanently reduce the amount of the
commitments thereunder by the amount of the Indebtedness so repaid, (ii) apply
the Net Cash Proceeds from such Asset Sale to repay any Restricted Subsidiary
Indebtedness and elect to permanently reduce the commitments thereunder by the
amount of the Indebtedness so repaid or (iii) apply such Net Cash Proceeds
within 365 days thereof, to an investment in properties and assets that will be
used in an Internet Service Business (or in Capital Stock and other securities
of any person that will become a Restricted Subsidiary as a result of such
investment to the extent such person owns properties and assets that will be
used
<PAGE>   107
                                      -99-

in an Internet Service Business) of the Company or any Restricted Subsidiary
("Replacement Assets").  Any Net Cash Proceeds from any Asset Sale that are
neither used to repay, and permanently reduce the commitments under, any
Restricted Subsidiary Indebtedness as set forth in clause (ii) of the preceding
sentence or invested in Replacement Assets within the 365-day period as set
forth in clause (iii) shall constitute "Excess Proceeds."  Any Excess Proceeds
not used as set forth in clause (i) of the second preceding sentence shall
constitute "Offer Excess Proceeds" subject to disposition as provided below.

         When the aggregate amount of Offer Excess Proceeds equals or exceeds
$10.0 million, the Company shall make an offer to purchase (an "Asset Sale
Offer"), from all holders of the Notes, that aggregate principal amount of
Notes as can be purchased by application of such Offer Excess Proceeds at a
price in cash equal to 100% of the principal amount thereof on any purchase
date, plus accrued and unpaid interest, if any, to any purchase date.  Each
Asset Sale Offer shall remain open for a period of 20 Business Days or such
longer period as may be required by law.  To the extent that the principal
amount of Notes tendered pursuant to an Asset Sale Offer is less than the Offer
Excess Proceeds, the Company or any Restricted Subsidiary may use such
deficiency for general corporate purposes.  If the principal amount of Notes
validly tendered and not withdrawn by holders thereof exceeds the amount of
Notes which can be purchased with the Offer Excess Proceeds, Notes to be
purchased will be selected on a pro rata basis.  Upon completion of such Asset
Sale Offer, the amount of Offer Excess Proceeds shall be reset to zero.

         Notice of an Asset Sale Offer shall be mailed by the Company not more
than 20 Business Days after the obligation to make such Asset Sale Offer arises
to the Holders of Notes at their last registered addresses with a copy to the
Trustee and the Paying Agent.  The Asset Sale Offer shall remain open from the
time of mailing for at least 20 Business Days and until 5:00 p.m., New York
City time, on the date fixed for Purchase of Notes validly tendered and not
withdrawn, which date shall be not later than the 30th Business Day following
the mailing of such Asset Sale Offer (the "Asset Sale Offer Purchase Date").
The notice, which shall govern the terms of the Asset Sale Offer, shall include
such disclosures as are required by law and shall state:

         (a)  that the Asset Sale Offer is being made pursuant to this Section
    10.15 and that all Notes tendered into the
<PAGE>   108
                                     -100-

    Asset Sale Offer will be accepted for payment; provided, however, that if
    the aggregate principal amount of Notes tendered in an Asset Sale Offer
    plus accrued interest at the expiration of such offer exceeds the aggregate
    amount of the Offer Excess Proceeds, the Company shall select the Notes to
    be purchased on a pro rata basis (with such adjustments as may be deemed
    appropriate by the Company so that only Notes in denominations of $1,000 or
    multiples thereof shall be purchased) and that the Asset Sale Offer shall
    remain open for a period of 20 Business Days or such longer period as may
    be required by law;

         (b)  the purchase price (including the amount of accrued interest, if
    any) for each Note, the Asset Sale Offer Purchase Date and the date on
    which the Asset Sale Offer expires;

         (c)  that any Note not tendered for payment will continue to accrue
    interest in accordance with the terms thereof;

         (d)  that, unless the Company shall default in the payment of the
    purchase price, any Note accepted for payment pursuant to the Asset Sale
    Offer shall cease to accrue interest after the Asset Sale Offer Purchase
    Date;

         (e)  that Holders electing to have Notes purchased pursuant to an
    Asset Sale Offer will be required to surrender their Notes to the Paying
    Agent at the address specified in the notice prior to 5:00 p.m., New York
    City time, on the Asset Sale Offer Purchase Date and must complete any form
    letter of transmittal proposed by the Company and acceptable to the Trustee
    and the Paying Agent;

         (f)  that Holders of Notes will be entitled to withdraw their election
    if the Paying Agent receives, not later than 5:00 p.m., New York City time,
    on the Asset Sale Offer Purchase Date, a facsimile transmission or letter
    setting forth the name of the Holders, the principal amount of Notes the
    Holders delivered for purchase, the Note certificate number (if any) and a
    statement that such Holder is withdrawing his election to have such Notes
    purchased;

         (g)  that Holders whose Notes are purchased only in part will be
    issued Notes of like tenor equal in principal amount to the unpurchased
    portion of the Notes surrendered;
<PAGE>   109
                                     -101-

         (h)  the instructions that Holders must follow in order to tender
    their Notes; and

         (i)  information concerning the business of the Company, the most
    recent annual and quarterly reports of the Company filed with the
    Commission pursuant to the Exchange Act (or, if the Company is not required
    to file any such reports with the SEC, the comparable reports prepared
    pursuant to Section 10.09), a description of material developments in the
    Company's business, information with respect to pro forma historical
    financial information after giving effect to such Asset Sale and such other
    information concerning the circumstances and relevant facts regarding such
    Asset Sale and Asset Sale Offer as would, in the good faith judgment of the
    Company, be material to a Holder of Notes in connection with the decision
    of such Holder as to whether or not it should tender Notes pursuant to the
    Asset Sale Offer.

         On the Asset Sale Offer Purchase Date, the Company will (i) accept for
payment Notes or portions thereof tendered pursuant to the Asset Sale Offer,
(ii) deposit with the Paying Agent money, in immediately available funds,
sufficient to pay the purchase price of all Notes or portions thereof so
tendered and accepted and (iii) deliver to the Trustee the Notes so accepted
together with an Officers' Certificate setting forth the Notes or portions
thereof tendered to and accepted for payment by the Company.  The Paying Agent
will promptly mail or deliver to the Holders of Notes so accepted payment in an
amount equal to the purchase price, and the Trustee shall promptly authenticate
and mail or deliver to such Holders a new Note of like tenor equal in principal
amount to any unpurchased portion of the Note surrendered.  Any Notes not so
accepted shall be promptly mailed or delivered by the Company to the Holder
thereof.  The Company will publicly announce the results of the Asset Sale
Offer not later than the first Business Day following the Asset Sale Offer
Purchase Date.

         If the Company is required to make an Asset Sale Offer, the Company
shall comply with all applicable tender offer rules, including to the extent
applicable, Section 14(e) and Rule 14e-1 under the Exchange Act, and any other
applicable securities laws or regulations.
<PAGE>   110
                                     -102-

         Section 10.16.   Limitation on Liens Securing Certain Indebtedness.

         The Company will not, and will not permit any Restricted Subsidiary
to, create, incur, assume or suffer to exist any Liens of any kind against or
upon any property or assets of the Company or any Restricted Subsidiary,
whether now owned or hereafter acquired, or any proceeds therefrom, which
secure either (x) Subordinated Indebtedness, unless the Notes are secured by a
Lien on such property, assets or proceeds that is senior in priority to the
Liens securing such Subordinated Indebtedness or (y) Indebtedness of the
Company that is not Subordinated Indebtedness, unless the Notes are equally and
ratably secured with the Liens securing such other Indebtedness, except, in the
case of this clause (y), Permitted Liens.

         Section 10.17.    Limitation on Business.

         The Company will not, and will not permit any of the Restricted
Subsidiaries to, engage in a business which is not substantially an Internet
Service Business.

         Section 10.18.   Limitation on Certain Guarantees and Indebtedness of
                          Restricted Subsidiaries.

         The Company will not permit any Restricted Subsidiary, directly or
indirectly, to assume, guarantee or in any other manner become liable with
respect to (i) any Subordinated Indebtedness or (ii) any Indebtedness of the
Company that is not Subordinated Indebtedness (other than, in the case of this
clause (ii), Indebtedness under any Permitted Credit Facility to the extent
constituting Permitted Indebtedness), unless, in each case, such Restricted
Subsidiary simultaneously executes and delivers a supplemental indenture
providing for the guarantee of payment of the Notes by such Restricted
Subsidiary on a basis senior to any such Subordinated Indebtedness or pari
passu with any such other Indebtedness referred to in clause (ii), as the case
may be.  Each guarantee created pursuant to such provisions is referred to as a
"Guarantee" and the issuer of each such Guarantee, so long as the Guarantee
remains outstanding, is referred to as a "Guarantor".

         Notwithstanding the foregoing, in the event of the unconditional
release of any Guarantor from its obligations in respect of the Indebtedness
which gave rise to the requirement that a Guarantee be given, such Guarantor
shall be released from all obligations under its Guarantee.  In addition, upon
<PAGE>   111
                                     -103-

any sale or disposition (by merger or otherwise) of any Guarantor by the
Company or a Restricted Subsidiary of the Company to any person that is not an
Affiliate of the Company or any of its Restricted Subsidiaries which is
otherwise in compliance with the terms of this Indenture and as a result of
which such Guarantor ceases to be a Restricted Subsidiary of the Company, such
Guarantor will be deemed to be automatically and unconditionally released from
all obligations under its Guarantee; provided that each such Guarantor is sold
or disposed of in accordance with Section 10.15 hereof.

         Section 10.19.   Limitation on Issuances and Sales of Preferred Stock
                          by Restricted Sub-sidiaries.

         The Company will not permit any Restricted Subsidiary to issue any
Preferred Stock (other than to the Company or a Restricted Subsidiary).

         Section 10.20.   Limitation on Dividends and Other Payment
                          Restrictions Affecting Restricted Subsidiaries.

         The Company will not, and will not permit any Restricted Subsidiary
to, directly or indirectly, create or otherwise enter into or cause to become
effective any consensual encumbrance or consensual restriction of any kind on
the ability of any Restricted Subsidiary to (a) pay dividends, in cash or
otherwise, or make any other distributions on its Capital Stock or any other
interest or participation in, or measured by, its profits to the extent owned
by the Company or any Restricted Subsidiary, (b) pay any Indebtedness owed to
the Company or any Restricted Subsidiary, (c) make any Investment in the
Company or any other Restricted Subsidiary or (d) transfer any of its
properties or assets to the Company or to any Restricted Subsidiary, except for
(in each case except as otherwise noted in the following clause (ii)) (i) any
encumbrance or restriction in existence on the Issue Date, (ii) any encumbrance
or restriction existing under agreements relating to an Investment in an ISP
(which in the case of clauses (a) and (b) shall not be permitted in the case of
ISPs that are Restricted Subsidiaries) to the extent consistent with past
practice, (iii) customary non-assignment provisions, (iv) any encumbrances or
restrictions pertaining to an asset subject to a Lien to the extent set forth
in the security documentation governing such Lien, (v) any encumbrance or
restriction applicable to a Restricted Subsidiary at the time that it becomes a
Restricted Subsidiary that is not created in contemplation
<PAGE>   112
                                     -104-

thereof, (vi) any encumbrance or restriction existing under any agreement that
refinances or replaces an agreement containing a restriction permitted by
clause (v) above; provided that the terms and conditions of any such
encumbrance or restriction are not materially less favorable to the holders of
Notes than those under or pursuant to the agreement being replaced or the
agreement evidencing the Indebtedness refinanced, (vii) any encumbrance or
restriction imposed upon a Restricted Subsidiary pursuant to an agreement which
has been entered into for the sale or disposition of all or substantially all
of the Capital Stock or assets of such Restricted Subsidiary or any Asset Sale
to the extent limited to the Capital Stock or assets in question and (viii) any
customary encumbrance or restriction applicable to a Restricted Subsidiary that
is contained in an agreement or instrument governing or relating to
Indebtedness contained in any Permitted Credit Facility; provided that the
provisions of such agreement permit the payment of interest and principal and
mandatory repurchases pursuant to the terms of this Indenture and the Notes and
other Indebtedness that is solely an obligation of the Company, but, provided,
further, that such agreement may nevertheless contain customary net worth,
leverage, invested capital and other financial covenants, customary covenants
regarding the merger of or sale of all or any substantial part of the assets of
the Company or any Restricted Subsidiary, customary restrictions on
transactions with affiliates, and customary subordination provisions governing
Indebtedness owed to the Company or any Restricted Subsidiary.

         Section 10.21.   Limitation on Designations of Unrestricted
                          Subsidiaries.

         The Company will not designate any Subsidiary of the Company (other
than a newly created Subsidiary in which no Investment has previously been
made) as an "Unrestricted Subsidiary" under this Indenture (a "Designation")
unless:

         (a) no Default shall have occurred and be continuing at the time of or
    after giving effect to such Designation;

         (b) except in the case of a Permitted Investment or an Investment made
    pursuant to clause (vii) or (ix) of the third paragraph of Section 10.13
    hereof, immediately after giving effect to such Designation, the Company
    would be able to incur $1.00 of Indebtedness under the proviso of Section
    10.11 hereof; and
<PAGE>   113
                                     -105-

         (c) the Company would not be prohibited under this Indenture from
    making an Investment at the time of Designation (assuming the effectiveness
    of such Designation) in an amount (the "Designation Amount") equal to the
    Fair Market Value of the net Investment of the Company or any other
    Restricted Subsidiary in such Restricted Subsidiary on such date.

         In the event of any such Designation, the Company shall be deemed to
have made an Investment constituting a Restricted Payment pursuant to Section
10.13 hereof for all purposes of this Indenture in the Designation Amount.
Neither the Company nor any Restricted Subsidiary shall at any time (x) provide
a guarantee of, or similar credit support to, any Indebtedness of any
Unrestricted Subsidiary (including of any undertaking, agreement or instrument
evidencing such Indebtedness); provided that the Company may pledge Capital
Stock or Indebtedness of any Unrestricted Subsidiary on a nonrecourse basis
such that the pledgee has no claim whatsoever against the Company other than to
obtain such pledged property, (y) be directly or indirectly liable for any
Indebtedness of any Unrestricted Subsidiary or (z) be directly or indirectly
liable for any other Indebtedness which provides that the holder thereof may
(upon notice, lapse of time or both) declare a default thereon (or cause the
payment thereof to be accelerated or payable prior to its final scheduled
maturity) upon the occurrence of a default with respect to any other
Indebtedness that is Indebtedness of an Unrestricted Subsidiary (including any
corresponding right to take enforcement action against such Unrestricted
Subsidiary), except in the case of clause (x) or (y) to the extent permitted
under Section 10.13 and Section 10.14 hereof.

         The Company will not revoke any Designation of a Subsidiary as an
Unrestricted Subsidiary (a "Revocation") unless:

         (a) no Default shall have occurred and be continuing at the time of
    and after giving effect to such Revocation; and

         (b) all Liens and Indebtedness of such Unrestricted Subsidiary
    outstanding immediately following such Revocation would, if incurred at
    such time, have been permitted to be incurred for all purposes of this
    Indenture.

         All Designations and Revocations must be evidenced by Board
Resolutions delivered to the Trustee certifying compliance with the foregoing
provisions.
<PAGE>   114
                                     -106-

         Section 10.22.   Compliance Certificates and Opinions.

         Upon any application or request by the Company to the Trustee to take
any action under any provision of this Indenture, the Company and any other
obligor on the Notes will furnish to the Trustee an Officers' Certificate
stating that all conditions precedent, if any, provided for in this Indenture
(including any covenants compliance with which constitutes a condition
precedent) relating to the proposed action have been complied with, and an
Opinion of Counsel stating that in the opinion of such counsel all such
conditions precedent, if any, have been complied with, except that, in the case
of any such application or request as to which the furnishing of such
documents, certificates and/or opinions is specifically required by any
provision of this Indenture relating to such particular application or request,
no additional certificate or opinion need be furnished.

         Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture will include:

         (i)     a statement that each individual signing such certificate or
    opinion has read such covenant or condition and the definitions herein
    relating thereto;

         (ii)    a brief statement as to the nature and scope of the
    examination or investigation upon which the statements or opinions
    contained in such certificate or opinion are based;

         (iii)   a statement that, in the opinion of each such individual, he
    has made such examination or investigation as is necessary to enable him to
    express an informed opinion as to whether such covenant or condition has
    been complied with; and

         (iv)    a statement as to whether, in the opinion of each such
    individual, such condition or covenant has been complied with.

         Section 10.23.   Reports.

         For periods prior to the fiscal quarter ending June 30, 1998, the
Company shall furnish without cost to each holder of Notes and file with the
Trustee (i) within 135 days after the end of each fiscal year of the Company,
(x) audited year-end consolidated financial statements (including a balance
<PAGE>   115
                                     -107-

sheet, income statement and statement of changes of cash flow) prepared in
accordance with GAAP and substantially in the form included in the Offering
Memorandum, (y) the information described in Item 303 of Regulation S-K under
the Securities Act with respect to such period, and (z) all pro forma and
historical financial information in respect of any significant transaction
consummated more than 60 days prior to the date such information is furnished
(and any other transaction for which such information is available at such
time) to the extent such financial information would be required in a filing on
Form 10-K with the SEC at such time; and (ii) within 60 days after the end of
each of the first three fiscal quarters of each fiscal year of the Company, (x)
unaudited quarterly consolidated financial statements (including a balance
sheet, income statement and statement of changes of cash flows) prepared in
accordance with GAAP and substantially in the form included in the Offering
Memorandum, (y) the information described in Item 303 of Regulation S-K under
the Securities Act with respect to such period and (z) all pro forma and
historical financial information in respect of any significant transaction
consummated more than 60 days prior to the date such information is furnished
(and any other transaction for which such information is available at such
time) to the extent such financial information would be required in a filing on
Form 10-Q with the SEC at such time. Whether or not the Company has a class of
securities registered under the Exchange Act, the Company shall furnish without
cost to each holder of Notes and file with the Trustee and file with the SEC,
(a) beginning with the fiscal quarter ending June 30, 1998 (i) within the
applicable time period required under the Exchange Act, after the end of each
fiscal year of the Company, the information required by Form 10-K (or any
successor form thereto) under the Exchange Act with respect to such period and
(ii) within the applicable time period required under the Exchange Act after
the end of each of the first three fiscal quarters of each fiscal year of the
Company, the information required by Form 10-Q (or any successor form thereto)
under the Exchange Act with respect to such period and (b) from and after
August 15, 1998, any current reports on Form 8-K (or any successor forms)
required to be filed under the Exchange Act.  Prior to such time as the Company
shall file with the SEC its first report on either of Form 10-K or Form 10-Q
under the Exchange Act, the Company shall telephonically make its executive
officers available to holders of Notes upon 10 days advance written request of
holders of at least 10% of the aggregate principal amount of Notes Outstanding
at the time of such request; provided, however, that holders of Notes may make
only one such request per fiscal quarter.
<PAGE>   116
                                     -108-

         Section 10.24.   Limitation on Status as Investment Company

         The Company will not and will not permit any of its Subsidiaries or
controlled Affiliates to, conduct its business in a fashion that would cause
the Company to be required to register as an "investment company" (as that term
is defined in the Investment Company Act of 1940, as amended (the "Investment
Company Act")), or otherwise become subject to regulation under the Investment
Company Act.  For purposes of establishing the Company's compliance with this
provision, any exemption which is or would become available under Section
3(c)(1) or Section 3(c)(7) of the Investment Company Act will be disregarded.

                                 ARTICLE ELEVEN

                           SATISFACTION AND DISCHARGE

         Section 11.01.   Satisfaction and Discharge of Indenture.  

         This Indenture shall cease to be of further effect (except as to
surviving rights or registration of transfer or exchange of Notes herein
expressly provided for) and the Trustee, on written demand of and at the
expense of the Company, shall execute proper instruments acknowledging
satisfaction and discharge of this Indenture, when either

         (a)  all Notes theretofore authenticated and delivered (other than (A)
    Notes which have been destroyed, lost or stolen and which have been
    replaced or paid as provided in Section 3.06 hereof and (B) Notes for whose
    payment money has theretofore been deposited in trust or segregated and
    held in trust by the Company and thereafter repaid to the Company or
    discharged from such trust, as provided in Section 10.03) have been
    delivered to the Trustee for cancellation; or

         (b)  (i)  all such Notes not theretofore delivered to the Trustee for
    cancellation have become due and payable and the Company has irrevocably
    deposited or caused to be deposited with the Trustee in trust an amount of
    money in dollars sufficient to pay and discharge the entire Indebtedness on
    such Notes not theretofore delivered to the Trustee for cancellation, for
    the principal of, premium, if any, and interest to the date of such
    deposit;
<PAGE>   117
                                     -109-

         (ii)    the Company has paid or caused to be paid all other sums
    payable hereunder by the Company; and

         (iii)   the Company has delivered to the Trustee (i) irrevocable
    instructions to apply the deposited money toward payment of the Notes at
    the Stated Maturities and the Redemption Dates thereof, and (ii) an
    Officers' Certificate and an Opinion of Counsel each stating that all
    conditions precedent herein provided for relating to the satisfaction and
    discharge of this Indenture have been complied with; provided, that such
    Opinion of Counsel may rely, as to matters of fact, upon an Officers'
    Certificate.

Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Company to the Trustee under Section 6.07 and, if money
shall have been deposited with the Trustee pursuant to subclause (a)(ii) of
this Section 11.01, the obligations of the Trustee under Section 11.02 and the
last paragraph of Section 10.03 shall survive.

         Section 11.02.   Application of Trust Money.

         Subject to the provisions of the last paragraph of Section 10.03, all
money deposited with the Trustee pursuant to Section 11.01 shall be held in
trust and applied by it, in accordance with the provisions of the Notes and
this Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the persons entitled thereto, of the principal of, premium, if
any, and interest on the Notes for whose payment such money has been deposited
with the Trustee.

                                 ARTICLE TWELVE

                                   REDEMPTION

         Section 12.01.   Notices to the Trustee.

         If the Company elects to redeem Notes pursuant to Paragraph 3 of the
Initial Notes or Paragraph 2 of the Exchange Notes, it shall notify the Trustee
of the Redemption Date and principal amount of Notes to be redeemed.

         The Company shall notify the Trustee of any redemption at least 45
days before the Redemption Date by an Officers'
<PAGE>   118
                                     -110-

Certificate, stating that such redemption will comply with the provisions
hereof and of the Notes.

         Section 12.02.   Selection of Notes To Be Redeemed.

         In the event that less than all of the Notes are to be redeemed at any
time, selection of such Notes for redemption will be made by the Trustee in
compliance with any applicable requirements of the principal national
securities exchange, if any, on which the Notes are listed or, if the Notes are
not then listed on a national securities exchange (or if the Notes are so
listed but the exchange does not impose requirements with respect to the
selection of debt securities for redemption), on a pro rata basis, by lot or by
such method as the Trustee in its sole discretion shall deem fair and
appropriate; provided, however, that no Notes of a principal amount of $1,000
or less shall be redeemed in part.

         The Trustee shall promptly notify the Company and the Registrar in
writing of the Notes selected for redemption and, in the case of any Notes
selected for partial redemption, the principal amount thereof to be redeemed.

         For all purposes of this Indenture, unless the context otherwise
requires, all provisions relating to redemption of Notes shall relate, in the
case of any Note redeemed or to be redeemed only in part, to the portion of the
principal amount of such Note which has been or is to be redeemed.

         Section 12.03.   Notice of Redemption.

         Notice of redemption shall be given by first-class mail, postage
prepaid, mailed not less than 30 nor more than 60 days prior to the Redemption
Date, to each Holder of Notes to be redeemed, at the address of such Holder
appearing in the Note register maintained by the Registrar.

         All notices of redemption shall identify the Notes to be redeemed and
shall state:

         (a)  the Redemption Date;

         (b)  the Redemption Price and the amount of accrued interest, if any,
    to be paid;

         (c)  that, unless the Company defaults in making the redemption
    payment, interest on Notes called for redemption ceases to accrue on and
    after the Redemption Date,
<PAGE>   119
                                     -111-

    and the only remaining right of the Holders of such Notes is to receive
    payment of the Redemption Price plus unpaid interest on the Notes through
    the Redemption Date, upon surrender to the Paying Agent of the Notes
    redeemed;

         (d)  if any Note is to be redeemed in part, the portion of the
    principal amount (equal to $1,000 or any integral multiple thereof) of such
    Note to be redeemed and that on and after the Redemption Date, upon
    surrender for cancellation of such Note to the Paying Agent, a new Note or
    Notes in the aggregate principal amount equal to the unredeemed portion
    thereof will be issued without charge to the Noteholder;

         (e)  that Notes called for redemption must be surrendered to the
    Paying Agent to collect the Redemption Price and the name and address of
    the Paying Agent; and

         (f)  the CUSIP number, if any, relating to such Notes.

         Notice of redemption of Notes to be redeemed at the election of the
Company shall be given by the Company or, at the Company's written request, by
the Trustee in the name and at the expense of the Company.

         Section 12.04.   Effect of Notice of Redemption.

         Once notice of redemption is mailed, Notes called for redemption
become due and payable on the Redemption Date and at the Redemption Price.
Upon surrender to the Paying Agent, such Notes called for redemption shall be
paid at the Redemption Price plus accrued interest, if any, to the Redemption
Date, but interest installments whose maturity is on or prior to such
Redemption Date will be payable on the relevant Interest Payment Dates to the
Holders of record at the close of business on the relevant record dates
referred to in the Notes.

         Section 12.05.   Deposit of Redemption Price.

         On or prior to any Redemption Date, the Company shall deposit with the
Paying Agent an amount of money in same day funds sufficient to pay the
Redemption Price of, and any accrued interest on, all the Notes or portions
thereof which are to be redeemed on that date, other than Notes or portions
thereof called for redemption on that date which have been delivered by the
Company to the Trustee for cancellation.
<PAGE>   120
                                     -112-

         If the Company complies with the preceding paragraph, then, unless the
Company defaults in the payment of such Redemption Price, interest on the Notes
to be redeemed will cease to accrue on and after the applicable Redemption
Date, whether or not such Notes are presented for payment, and the Holders of
such Notes shall have no further rights with respect to such Notes except for
the right to receive the Redemption Price plus unpaid interest on the Notes
through the Redemption Date, upon surrender of such Notes.  If any Note called
for redemption shall not be so paid upon surrender thereof for redemption, the
principal, premium, if any, and, to the extent lawful, accrued interest thereon
shall, until paid, bear interest from the Redemption Date at the rate provided
in the Notes.

         Section 12.06.   Notes Redeemed or Purchased in Part.

         Upon surrender to the Paying Agent of a Note which is to be redeemed
in part, the Company shall execute and the Trustee shall authenticate and
deliver to the Holder of such Note without service charge, a new Note or Notes,
of any authorized denomination as requested by such Holder in aggregate
principal amount equal to, and in exchange for, the unredeemed portion of the
principal of the Note so surrendered that is not redeemed.
<PAGE>   121
                                     -113-

         IN WITNESS WHEREOF, the parties hereto have caused this Indenture to
be duly executed as of the day and year first above written.


                                        VERIO INC.

                                        By: /s/ CARLA HAMRE DONELSON
                                            ------------------------
                                            Name: Carla Hamre Donelson
                                            Title: Vice President & General 
                                                   Counsel
                  
                                        FIRST TRUST NATIONAL ASSOCIATION, as
                                            Trustee

                                        By: /s/ RICHARD H. PROKOSCH         
                                            -----------------------
                                            Name: Richard H. Prokosch
                                            Title: Assistant Vice President
<PAGE>   122

                                                                     EXHIBIT A-1


                                 [FORM OF NOTE]


         THE SECURITIES EVIDENCED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY STATE OR OTHER
SECURITIES LAWS. NEITHER THIS SECURITY NOR ANY INTEREST OR PARTICIPATION HEREIN
MAY BE REOFFERED, SOLD, ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE
DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR UNLESS THE TRANSACTION IS
EXEMPT FROM, OR NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES
ACT. THE HOLDER OF THIS SECURITY BY ITS ACCEPTANCE HEREOF (1) REPRESENTS THAT
(A) IT IS A "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
SECURITIES ACT) OR (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS DEFINED
IN RULE 501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT) (AN "ACCREDITED
INVESTOR") OR (C) IT IS NOT A U.S. PERSON AND IS ACQUIRING THIS SECURITY IN AN
"OFFSHORE TRANSACTION" PURSUANT TO RULE 903 OR 904 OF REGULATION S, (2) AGREES
THAT IT WILL NOT PRIOR TO (X) THE DATE WHICH IS TWO YEARS (OR SUCH SHORTER
PERIOD OF TIME AS PERMITTED BY RULE 144 UNDER THE SECURITIES ACT OR ANY
SUCCESSOR PROVISION THEREUNDER) AFTER THE LATER OF THE ORIGINAL ISSUE DATE
HEREOF (OR OF ANY PREDECESSOR OF THIS SECURITY) OR THE LAST DATE ON WHICH THE
COMPANY OR ANY AFFILIATE OF THE COMPANY WAS THE OWNER OF THIS SECURITY OR ANY
PREDECESSOR OF THIS SECURITY AND (Y) SUCH LATER DATE, IF ANY, AS MAY BE REQUIRED
BY APPLICABLE LAWS (THE "RESALE RESTRICTION TERMINATION DATE"), OFFER, SELL OR
OTHERWISE TRANSFER THIS SECURITY EXCEPT (A) TO THE COMPANY OR ANY SUBSIDIARY
THEREOF, (B) PURSUANT TO A REGISTRATION STATEMENT WHICH HAS BEEN DECLARED
EFFECTIVE UNDER THE SECURITIES ACT, (C) FOR SO LONG AS THE SECURITIES ARE
ELIGIBLE FOR RESALE PURSUANT TO RULE 144A, TO A PERSON IT REASONABLY BELIEVES IS
A "QUALIFIED INSTITUTIONAL BUYER" AS DEFINED IN RULE 144A UNDER THE SECURITIES
ACT THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED
INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN
RELIANCE ON RULE 144A, (D) PURSUANT TO OFFERS AND SALES TO NON-U.S. PERSONS THAT
OCCUR OUTSIDE THE UNITED STATES WITHIN THE MEANING OF REGULATION S UNDER THE
SECURITIES ACT, PURSUANT TO RULE 904 OF REGULATION S, (E) TO AN ACCREDITED
INVESTOR THAT IS ACQUIRING THE SECURITIES FOR ITS OWN ACCOUNT, OR FOR THE
ACCOUNT OF SUCH AN ACCREDITED INVESTOR, FOR INVESTMENT PURPOSES AND NOT WITH A
VIEW TO, OR FOR OFFER OR SALE IN CONNECTION WITH, ANY DISTRIBUTION IN VIOLATION
OF THE SECURITIES ACT (AND IF ACQUIRING THE 


                                     A-1-1
<PAGE>   123


SECURITIES FROM SUCH AN ACCREDITED INVESTOR, IS ACQUIRING SECURITIES HAVING AN
AGGREGATE PRINCIPAL AMOUNT OF NOT LESS THAN $250,000), OR (F) PURSUANT TO
ANOTHER AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES
ACT AND (3) AGREES THAT IT WILL GIVE TO EACH PERSON TO WHOM THIS SECURITY IS
TRANSFERRED A NOTICE SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND; PROVIDED THAT
THE COMPANY, THE TRUSTEE, THE TRANSFER AGENT AND THE REGISTRAR SHALL HAVE THE
RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER (I) PURSUANT TO CLAUSE (D), (E)
OR (F) TO REQUIRE THE DELIVERY OF AN OPINION OF COUNSEL, CERTIFICATION AND/OR
OTHER INFORMATION SATISFACTORY TO EACH OF THEM, AND (II) IN EACH OF THE
FOREGOING CASES, TO REQUIRE THAT A CERTIFICATION OF TRANSFER IN THE FORM
APPEARING ON THE OTHER SIDE OF THIS SECURITY IS COMPLETED AND DELIVERED BY THE
TRANSFEROR TO THE TRUSTEE. THIS LEGEND WILL BE REMOVED UPON THE REQUEST OF THE
HOLDER AFTER THE RESALE RESTRICTION TERMINATION DATE. AS USED HEREIN, THE TERMS
"OFFSHORE TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE RESPECTIVE
MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE SECURITIES ACT.


                                     A-1-2
<PAGE>   124

                                        
                                   VERIO INC.
                                        
                               -----------------
                                        
                                        
                    10-3/8% SENIOR NOTES DUE 2005, SERIES A


CUSIP No. __________
No. ___________                                                    $175,000,000


         VERIO INC., a corporation incorporated under the laws of the State of
Delaware (herein called the "Company," which term includes any successor
corporation under this Indenture hereinafter referred to), for value received,
hereby promises to pay to _______________ or registered assigns, the principal
sum of _______________ Dollars on April 1, 2005, at the office or agency of the
Company referred to below, and to pay interest thereon on April 1 and October 1
(each, an "Interest Payment Date"), of each year, commencing on October 1, 1998,
accruing from the Issue Date or from the most recent Interest Payment Date to
which interest has been paid or duly provided for, at the rate of 10-3/8% per
annum, until the principal hereof is paid or duly provided for. Interest shall
be computed on the basis of a 360-day year of twelve 30-day months.

         The interest so payable, and punctually paid or duly provided for, on
any Interest Payment Date will, as provided in the Indenture referred to on the
reverse hereof, be paid to the person in whose name this Note (or one or more
Predecessor Notes) is registered at the close of business on the March 15 and
September 15 (each, a "Regular Record Date"), whether or not a Business Day, as
the case may be, next preceding such Interest Payment Date. Any such interest
not so punctually paid, or duly provided for, and interest on such defaulted
interest at the then applicable interest rate borne by the Notes, to the extent
lawful, shall forthwith cease to be payable to the Holder on such Regular Record
Date, and may be paid to the person in whose name this Note (or one or more
Predecessor Notes) is registered at the close of business on a Special Record
Date for the payment of such defaulted interest to be fixed by the Trustee,
notice of which shall be given to Holders of Notes not less than 10 days prior
to such Special Record Date, or may be paid at any time in any other lawful
manner not inconsistent with the requirements of any securities exchange on
which the Notes may be listed, and upon such notice as may be required by such
exchange, all as more fully provided in such Indenture.


                                     A-1-3
<PAGE>   125


         Payment of the principal of, premium, if any, and interest on this Note
will be made at the office or agency of the Company maintained for that purpose
in the Borough of Manhattan in The City of New York, State of New York, or at
such other office or agency of the Company as may be maintained for such
purpose, in such coin or currency of the United States of America as at the time
of payment is legal tender for payment of public and private debts; provided,
however, that payment of interest may be made at the option of the Company by
check mailed to the address of the person entitled thereto as such address shall
appear on the Note Register.

         Reference is hereby made to the further provisions of this Note set
forth on the reverse hereof.

         Unless the certificate of authentication hereon has been duly executed
by the Trustee referred to on the reverse hereof by manual signature, this Note
shall not be entitled to any benefit under the Indenture, or be valid or
obligatory for any purpose.



                  [Remainder of Page Intentionally Left Blank]




                                     A-1-4
<PAGE>   126


         IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed.

Dated:                                   VERIO INC.


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

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


                     TRUSTEE'S CERTIFICATE OF AUTHENTICATION


         This is one of the 10-3/8% Senior Notes Due 2005, Series A, referred to
in the within-mentioned Indenture.

                                         FIRST TRUST NATIONAL ASSOCIATION, as 
                                            Trustee


                                         By: 
                                            -----------------------------------
                                               Authorized Signatory



                                     A-1-5
<PAGE>   127


                                [REVERSE OF NOTE]


         1. Indenture. This Note is one of a duly authorized issue of Notes of
the Company designated as its 10-3/8% Senior Notes Due 2005, Series A (herein
called the "Initial Notes"). The Notes are limited (except as otherwise provided
in the Indenture referred to below) in aggregate principal amount to
$175,000,000, which may be issued under an indenture (herein called the
"Indenture") dated as of March 25, 1998, by and between the Company and First
Trust National Association, as trustee (herein called the "Trustee," which term
includes any successor Trustee under the Indenture), to which Indenture and all
indentures supplemental thereto reference is hereby made for a statement of the
respective rights, limitations of rights, duties, obligations and immunities
thereunder of the Company, the Trustee and the Holders of the Notes, and of the
terms upon which the Notes are, and are to be, authenticated and delivered. The
Notes include the Initial Notes, the Private Exchange Notes and the Unrestricted
Notes (including the Exchange Notes referred to below), issued in exchange for
the Initial Notes pursuant to the Registration Rights Agreement. The Initial
Notes and the Unrestricted Notes are treated as a single class of securities
under the Indenture.

         All capitalized terms used in this Note which are defined in the
Indenture and not otherwise defined herein shall have the meanings assigned to
them in the Indenture.

                  The terms of the Notes include those stated in the Indenture
and those made part of the Indenture by reference to the Trust Indenture Act of
1939 (15 U.S.C. ss.ss. 77aaa-77bbbb) (the "TIA"), as in effect on the date of
the Indenture. Notwithstanding anything to the contrary herein, the Notes are
subject to all such terms, and Holders of Notes are referred to the Indenture
and the TIA for a statement of such terms.

         No reference herein to the Indenture and no provisions of this Note or
of the Indenture shall alter or impair the obligation of the Company, which is
absolute and unconditional, to pay the principal of, premium, if any, and
interest on this Note at the times, place, and rate, and in the coin or
currency, herein prescribed.

         2. Registration Rights. Pursuant to the Registration Rights Agreement
by and among the Company and the Initial Purchasers, the Company will be
obligated to consummate an exchange offer pursuant to which the Holder of this
Note shall 

                                     A-1-6
<PAGE>   128

have the right to exchange this Note for 10-3/8% Senior Notes Due 2005, Series
B, of the Company (herein called the "Exchange Notes"), which have been
registered under the Securities Act, in like principal amount and having
identical terms as the Notes (other than as set forth in this paragraph). The
Holders of Notes shall be entitled to receive certain additional interest
payments in the event such exchange offer is not consummated and upon certain
other conditions, all pursuant to and in accordance with the terms of the
Registration Rights Agreement.

                  3. Redemption. The Notes will be redeemable, at the option of
the Company, in whole or in part, on or after April 1, 2002 upon not less than
30 nor more than 60 days' written notice at the redemption prices (expressed as
percentages of principal amount) set forth below, plus accrued and unpaid
interest thereon, if any, to the applicable redemption date, if redeemed during
the twelve-month period beginning on April 1 of each of the years indicated
below:

<TABLE>
<CAPTION>
                               Year                      Percentage
                               ----                      ----------
<S>        <C>                                           <C>     
           2002....................................      105.188%
           2003....................................      102.594%
           2004....................................      100.000%
</TABLE>


         Notwithstanding the foregoing, in the event that after the Issue Date
and prior to April 1, 2001 the Company issues, in one or more transactions,
Capital Stock (other than Disqualified Stock) of the Company to WorldCom or one
or more Strategic Equity Investors or in any Public Equity Offering for
aggregate gross cash proceeds of $50.0 million or more (an "Equity Sale"), the
Company may redeem, at its option, up to a maximum of 35% of the initially
Outstanding aggregate principal amount of Notes from the net proceeds thereof at
a redemption price equal to 110.375% of the principal amount of the Notes,
together with accrued and unpaid interest to the date of redemption; provided
that not less than $113.75 million aggregate principal amount of Notes is
Outstanding following such redemption. Any such redemption may only be effected
once and must be effected upon not less than 30 nor more than 60 days' notice
given within 180 days after such Equity Sale.

         4. Offers to Purchase. Sections 10.10 and 10.15 of the Indenture
provide that upon the occurrence of a Change of Control and following certain
Asset Sales, and subject to certain conditions and limitations contained
therein, the Company 


                                      A-1-7
<PAGE>   129

shall make an offer to purchase all or a portion of the Notes in accordance with
the procedures set forth in the Indenture.

         5. Defaults and Remedies. If an Event of Default occurs and is
continuing, the principal of all of the Outstanding Notes, plus all accrued and
unpaid interest, if any, to and including the date the Notes are paid, may be
declared due and payable in the manner and with the effect provided in this
Indenture.

         6. Defeasance. This Indenture contains provisions (which provisions
apply to this Note) for defeasance at any time of (a) the entire indebtedness of
the Company on this Note and (b) certain restrictive covenants and related
Defaults and Events of Default, in each case upon compliance by the Company with
certain conditions set forth therein.

         7. Amendments and Waivers. This Indenture permits, with certain
exceptions as provided therein, the amendment thereof and the modification of
the rights and obligations of the Company and the rights of the Holders under
this Indenture at any time by the Company and the Trustee with the consent of
the Holders of not less than a majority in aggregate principal amount of the
Notes at the time Outstanding. This Indenture also contains provisions
permitting the Holders of specified percentages in aggregate principal amount of
the Notes at the time Outstanding, on behalf of the Holders of all the Notes, to
waive compliance by the Company with certain provisions of this Indenture and
certain past Defaults under this Indenture and this Note and their consequences.
Any such consent or waiver by or on behalf of the Holder of this Note shall be
conclusive and binding upon such Holder and upon all future Holders of this Note
and of any Note issued upon the registration of transfer hereof or in exchange
herefor or in lieu hereof whether or not notation of such consent or waiver is
made upon this Note.

         8. Denominations, Transfer and Exchange. The Notes are issuable only in
registered form without coupons in denominations of $1,000 and any integral
multiple thereof. As provided in this Indenture and subject to certain
limitations therein set forth, the Notes are exchangeable for a like aggregate
principal amount of Notes of a different authorized denomination, as requested
by the Holder surrendering the same.

         As provided in the Indenture and subject to certain limitations therein
set forth, the transfer of this Note is registrable on the Note Register of the
Company, upon surrender 




                                     A-1-8
<PAGE>   130

of this Note for registration of transfer at the office or agency of the Company
maintained for such purpose in the Borough of Manhattan in The City of New York,
State of New York, or at such other office or agency of the Company as may be
maintained for such purpose, duly endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Registrar
duly executed by, the Holder hereof or his attorney duly authorized in writing,
and thereupon one or more new Notes, of authorized denominations and for the
same aggregate principal amount, will be issued to the designated transferee or
transferees.

         No service charge shall be made for any registration of transfer or
exchange or redemption of Notes, but the Company may require payment of a sum
sufficient to cover any tax or other governmental charge payable in connection
therewith.

         9. Persons Deemed Owners. Prior to and at the time of due presentment
of this Note for registration of transfer, the Company, the Trustee and any
agent of the Company or the Trustee may treat the person in whose name this Note
is registered as the owner hereof for all purposes, whether or not this Note
shall be overdue, and neither the Company, the Trustee nor any agent shall be
affected by notice to the contrary.

         10. GOVERNING LAW. THIS INDENTURE, THIS NOTE AND ANY GUARANTEE SET
FORTH BELOW SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF
THE STATE OF NEW YORK WITHOUT GIVING EFFECT TO PRINCIPLES OF CONFLICTS OF LAW.

         The Company will furnish to any Holder of a Note upon written request
and without charge a copy of this Indenture. Requests may be made to: Verio
Inc., 8005 South Chester Street, Suite 200, Englewood, Colorado 80112.




                                     A-1-9
<PAGE>   131

                                 ASSIGNMENT FORM


If you the holder want to assign this Note, fill in the form below and have your
signature guaranteed:

I or we assign and transfer this Note to

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

(Insert assignee's social security or tax ID number)
                                                     ---------------------------

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

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

--------------------------------------------------------------------------------
(Print or type assignee's name, address and zip code) and irrevocably appoint

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

agent to transfer this Note on the books of the Company. The agent may
substitute another to act for such agent.

         In connection with any transfer of this Note occurring prior to the
date which is the earlier of (i) the date of the declaration by the SEC of the
effectiveness of a registration statement under the Securities Act of 1933, as
amended (the "Securities Act"), covering resales of this Note (which
effectiveness shall not have been suspended or terminated at the date of the
transfer) and (ii) the date two years (or such shorter period of time as
permitted by Rule 144 under the Securities Act or any successor provision
thereunder) after the later of the original issuance date appearing on the face
of this Note (or any Predecessor Note) or the last date on which the Company or
any Affiliate of the Company was the owner of this Note (or any Predecessor
Note), the undersigned confirms that it has not utilized any general
solicitation or general advertising in connection with the transfer and that:

                                   [Check One]

[   ] (a)     this Note is being transferred in compliance with the exemption 
              from registration under the Securities Act provided by Rule 144A 
              thereunder.



                                     A-1-10
<PAGE>   132

                                       or

[   ] (b)     this Note is being transferred other than in accordance with (a) 
              above and documents, including (i) a transferee certificate
              substantially in the form of Exhibit C to this Indenture in the
              case of a transfer to non-QIB Accredited Investors or (ii) a
              transferor certificate substantially in the form of Exhibit D to
              this Indenture in the case of a transfer pursuant to Regulation S,
              are being furnished which comply with the conditions of transfer
              set forth in this Note and this Indenture.

If none of the foregoing boxes is checked and, in the case of (b) above, if the
appropriate document is not attached or otherwise furnished to the Trustee, the
Trustee or Registrar shall not be obligated to register this Note in the name of
any person other than the Holder hereof unless and until the conditions to any
such transfer of registration set forth herein and in Section 3.17 of this
Indenture shall have been satisfied.



Date:                     Your signature:
     -----------------                   ----------------------------------
                                         (Sign exactly as your name appears
                                         on the other side of this Note)

                                     By:
                                         ----------------------------------
                                          NOTICE:  To be executed by an 
                                          executive officer


Signature Guarantee:
                     -----------------------------------

              TO BE COMPLETED BY PURCHASER IF (a) ABOVE IS CHECKED

         The undersigned represents and warrants that it is purchasing this Note
for its own account or an account with respect to which it exercises sole
investment discretion and that it and any such account is a "qualified
institutional buyer" within the meaning of Rule 144A under the Securities Act
and is aware that the sale to it is being made in reliance on Rule 144A and
acknowledges that it has received such information regarding the Company as the
undersigned has requested pursuant to Rule 144A (including the information
specified in Rule 144A(d)(4)) or has determined not to request such information
and that it is aware that the transferor is relying upon 


                                     A-1-11
<PAGE>   133

the undersigned's foregoing representations in order to claim the exemption from
registration provided by Rule 144A.

Dated:
     -----------------                   ----------------------------------
                                         NOTICE:  To be executed by an 
                                                  executive officer



                                     A-1-12
<PAGE>   134

                       OPTION OF HOLDER TO ELECT PURCHASE


         If you wish to have this Note purchased by the Company pursuant to
Section 10.10 or 10.15 of the Indenture, check the appropriate box:

         Section 10.10 [  ]                Section 10.15 [  ]

         If you wish to have a portion of this Note purchased by the Company
pursuant to Section 10.10 or 10.15 of the Indenture, state the amount:

                                 $ _____________


Date:                     Your signature:
     -----------------                   ----------------------------------
                                         (Sign exactly as your name appears
                                         on the other side of this Note)

                                     By:
                                         ----------------------------------
                                          NOTICE:  To be executed by an 
                                          executive officer


Signature Guarantee:
                     -----------------------------------



                                     A-1-13
<PAGE>   135

                                                                     EXHIBIT A-2


                                   VERIO INC.

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


                     10-3/8% SENIOR NOTES DUE 2005, SERIES B


CUSIP No. __________
No. ___________                                                       $


         VERIO INC., a corporation incorporated under the laws of the State of
Delaware (herein called the "Company," which term includes any successor
corporation under this Indenture hereinafter referred to), for value received,
hereby promises to pay to _______________ or registered assigns, the principal
sum of _______________ Dollars on April 1, 2005, at the office or agency of the
Company referred to below, and to pay interest thereon on April 1 and October 1
(each, an "Interest Payment Date"), of each year, commencing on October 1, 1998,
accruing from the Issue Date or from the most recent Interest Payment Date to
which interest has been paid or duly provided for, at the rate of 10-3/8% per
annum, until the principal hereof is paid or duly provided for. Interest shall
be computed on the basis of a 360-day year of twelve 30-day months.

         The interest so payable, and punctually paid or duly provided for, on
any Interest Payment Date will, as provided in the Indenture referred to on the
reverse hereof, be paid to the person in whose name this Note (or one or more
Predecessor Notes) is registered at the close of business on the March 15 and
September 15 (each, a "Regular Record Date"), whether or not a Business Day, as
the case may be, next preceding such Interest Payment Date. Any such interest
not so punctually paid, or duly provided for, and interest on such defaulted
interest at the then applicable interest rate borne by the Notes, to the extent
lawful, shall forthwith cease to be payable to the Holder on such Regular Record
Date, and may be paid to the person in whose name this Note (or one or more
Predecessor Notes) is registered at the close of business on a Special Record
Date for the payment of such defaulted interest to be fixed by the Trustee,
notice of which shall be given to Holders of Notes not less than 10 days prior
to such Special Record Date, or may be paid at any time in any other lawful
manner not inconsistent with the requirements of any securities exchange on
which the Notes may be listed, and upon such notice as may be required by such
exchange, all as more fully provided in such Indenture.



                                     A-2-1
<PAGE>   136
         Payment of the principal of, premium, if any, and interest on this Note
will be made at the office or agency of the Company maintained for that purpose
in the Borough of Manhattan in The City of New York, State of New York, or at
such other office or agency of the Company as may be maintained for such
purpose, in such coin or currency of the United States of America as at the time
of payment is legal tender for payment of public and private debts; provided,
however, that payment of interest may be made at the option of the Company by
check mailed to the address of the person entitled thereto as such address shall
appear on the Note Register.

         Reference is hereby made to the further provisions of this Note set
forth on the reverse hereof.

         Unless the certificate of authentication hereon has been duly executed
by the Trustee referred to on the reverse hereof by manual signature, this Note
shall not be entitled to any benefit under the Indenture, or be valid or
obligatory for any purpose.

                  [Remainder of Page Intentionally Left Blank]



                                     A-2-2
<PAGE>   137


         IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed.

Dated:                                   VERIO INC.


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

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


                  TRUSTEE'S CERTIFICATE OF AUTHENTICATION


                  This is one of the 10-3/8% Senior Notes Due 2005, Series B,
referred to in the within-mentioned Indenture.

                                         FIRST TRUST NATIONAL ASSOCIATION, 
                                            as Trustee


                                         By:
                                            ------------------------------ 
                                                 Authorized Signatory



                                     A-2-3
<PAGE>   138

                                [REVERSE OF NOTE]


         1. Indenture. This Note is one of a duly authorized issue of Notes of
the Company designated as its 10-3/8% Senior Notes Due 2005, Series B (herein
called the "Initial Notes"). The Notes are limited (except as otherwise provided
in the Indenture referred to below) in aggregate principal amount to
$175,000,000, which may be issued under an indenture (herein called the
"Indenture") dated as of March 25, 1998, by and between the Company and First
Trust National Association, as trustee (herein called the "Trustee," which term
includes any successor Trustee under the Indenture), to which Indenture and all
indentures supplemental thereto reference is hereby made for a statement of the
respective rights, limitations of rights, duties, obligations and immunities
thereunder of the Company, the Trustee and the Holders of the Notes, and of the
terms upon which the Notes are, and are to be, authenticated and delivered. The
Notes include the Initial Notes, the Private Exchange Notes and the Unrestricted
Notes (including the Exchange Notes referred to below), issued in exchange for
the Initial Notes pursuant to the Registration Rights Agreement. The Initial
Notes and the Unrestricted Notes are treated as a single class of securities
under the Indenture.

         All capitalized terms used in this Note which are defined in the
Indenture and not otherwise defined herein shall have the meanings assigned to
them in the Indenture.

         The terms of the Notes include those stated in the Indenture and those
made part of the Indenture by reference to the Trust Indenture Act of 1939 (15
U.S.C. Sections 77aaa-77bbbb) (the "TIA"), as in effect on the date of the
Indenture. Notwithstanding anything to the contrary herein, the Notes are
subject to all such terms, and Holders of Notes are referred to the Indenture
and the TIA for a statement of such terms.

         No reference herein to the Indenture and no provisions of this Note or
of the Indenture shall alter or impair the obligation of the Company, which is
absolute and unconditional, to pay the principal of, premium, if any, and
interest on this Note at the times, place, and rate, and in the coin or
currency, herein prescribed.

         2. Redemption. The Notes will be redeemable, at the option of the
Company, in whole or in part, on or after April 1, 2002 upon not less than 30
nor more than 60 days' written notice at the redemption prices (expressed as
percentages of principal amount) set forth below, plus accrued and unpaid
interest thereon, if any, to the applicable redemption 



                                     A-2-4
<PAGE>   139

date, if redeemed during the twelve-month period beginning on April 1 of each of
the years indicated below:

<TABLE>
<CAPTION>
                               Year                     Percentage
                               ----                     ----------
<S>        <C>                                           <C>     
           2002....................................      105.188%
           2003....................................      102.594%
           2004....................................      100.000%
</TABLE>

         Notwithstanding the foregoing, in the event that after the Issue Date
and prior to April 1, 2001 the Company issues, in one or more transactions,
Capital Stock (other than Disqualified Stock) of the Company to WorldCom or one
or more Strategic Equity Investors or in any Public Equity Offering for
aggregate gross cash proceeds of $50.0 million or more (an "Equity Sale"), the
Company may redeem, at its option, up to a maximum of 35% of the initially
Outstanding aggregate principal amount of Notes from the net proceeds thereof at
a redemption price equal to 110.375% of the principal amount of the Notes,
together with accrued and unpaid interest to the date of redemption; provided
that not less than $113.75 million aggregate principal amount of Notes is
Outstanding following such redemption. Any such redemption may only be effected
once and must be effected upon not less than 30 nor more than 60 days' notice
given within 180 days after such Equity Sale.

         3. Offers to Purchase. Sections 10.10 and 10.15 of the Indenture
provide that upon the occurrence of a Change of Control and following certain
Asset Sales, and subject to certain conditions and limitations contained
therein, the Company shall make an offer to purchase all or a portion of the
Notes in accordance with the procedures set forth in the Indenture.

         4. Defaults and Remedies. If an Event of Default occurs and is
continuing, the principal of all of the Outstanding Notes, plus all accrued and
unpaid interest, if any, to and including the date the Notes are paid, may be
declared due and payable in the manner and with the effect provided in this
Indenture.

         5. Defeasance. This Indenture contains provisions (which provisions
apply to this Note) for defeasance at any time of (a) the entire indebtedness of
the Company on this Note and (b) certain restrictive covenants and related
Defaults and Events of Default, in each case upon compliance by the Company with
certain conditions set forth therein.

         6. Amendments and Waivers. This Indenture permits, with certain
exceptions as provided therein, the amendment thereof and the modification of
the rights and obligations of 




                                     A-2-5
<PAGE>   140

the Company and the rights of the Holders under this Indenture at any time by
the Company and the Trustee with the consent of the Holders of not less than a
majority in aggregate principal amount of the Notes at the time Outstanding.
This Indenture also contains provisions permitting the Holders of specified
percentages in aggregate principal amount of the Notes at the time Outstanding,
on behalf of the Holders of all the Notes, to waive compliance by the Company
with certain provisions of this Indenture and certain past Defaults under this
Indenture and this Note and their consequences. Any such consent or waiver by or
on behalf of the Holder of this Note shall be conclusive and binding upon such
Holder and upon all future Holders of this Note and of any Note issued upon the
registration of transfer hereof or in exchange herefor or in lieu hereof whether
or not notation of such consent or waiver is made upon this Note.

         7. Denominations, Transfer and Exchange. The Notes are issuable only in
registered form without coupons in denominations of $1,000 and any integral
multiple thereof. As provided in this Indenture and subject to certain
limitations therein set forth, the Notes are exchangeable for a like aggregate
principal amount of Notes of a different authorized denomination, as requested
by the Holder surrendering the same.

         As provided in the Indenture and subject to certain limitations therein
set forth, the transfer of this Note is registrable on the Note Register of the
Company, upon surrender of this Note for registration of transfer at the office
or agency of the Company maintained for such purpose in the Borough of Manhattan
in The City of New York, State of New York, or at such other office or agency of
the Company as may be maintained for such purpose, duly endorsed by, or
accompanied by a written instrument of transfer in form satisfactory to the
Company and the Registrar duly executed by, the Holder hereof or his attorney
duly authorized in writing, and thereupon one or more new Notes, of authorized
denominations and for the same aggregate principal amount, will be issued to the
designated transferee or transferees.

         No service charge shall be made for any registration of transfer or
exchange or redemption of Notes, but the Company may require payment of a sum
sufficient to cover any tax or other governmental charge payable in connection
therewith.

         8. Persons Deemed Owners. Prior to and at the time of due presentment
of this Note for registration of transfer, the Company, the Trustee and any
agent of the Company or the Trustee may treat the person in whose name this Note
is registered as the owner hereof for all purposes, whether or not this 




                                     A-2-6
<PAGE>   141

Note shall be overdue, and neither the Company, the Trustee nor any agent shall
be affected by notice to the contrary.

         9. GOVERNING LAW. THIS INDENTURE, THIS NOTE AND ANY GUARANTEE SET FORTH
BELOW SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE
STATE OF NEW YORK WITHOUT GIVING EFFECT TO PRINCIPLES OF CONFLICTS OF LAW.

         The Company will furnish to any Holder of a Note upon written request
and without charge a copy of this Indenture. Requests may be made to: Verio
Inc., 8005 South Chester Street, Suite 200, Englewood, Colorado 80112.




                                     A-2-7
<PAGE>   142

                                 ASSIGNMENT FORM


If you the holder want to assign this Note, fill in the form below and have your
signature guaranteed:

I or we assign and transfer this Note to

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

(Insert assignee's social security or tax ID number)

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

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

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

(Print or type assignee's name, address and zip code) and irrevocably appoint

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

agent to transfer this Note on the books of the Company. The agent may
substitute another to act for such agent.

Date:                     Your signature:
     -----------------                   ----------------------------------
                                         (Sign exactly as your name appears
                                         on the other side of this Note)

                                     By:
                                         ----------------------------------
                                          NOTICE:  To be executed by an 
                                          executive officer


Signature Guarantee:
                     -----------------------------------


                                     A-2-8
<PAGE>   143


                       OPTION OF HOLDER TO ELECT PURCHASE


         If you wish to have this Note purchased by the Company pursuant to
Section 10.10 or 10.15 of this Indenture, check the appropriate box:

         Section 10.10 [   ]                Section 10.15 [   ]

         If you wish to have a portion of this Note purchased by the Company
pursuant to Section 10.10 or 10.15 of this Indenture, state the amount:

                                  $ __________

Date:                     Your signature:
     -----------------                   ----------------------------------
                                         (Sign exactly as your name appears
                                         on the other side of this Note)

                                     By:
                                         ----------------------------------
                                          NOTICE:  To be executed by an 
                                          executive officer


Signature Guarantee:
                     -----------------------------------



                                     A-2-9
<PAGE>   144



                                                                       EXHIBIT B

                    FORM OF LEGEND FOR BOOK-ENTRY SECURITIES


                  Any Global Note authenticated and delivered hereunder shall 
bear a legend (which would be in addition to any other legends required in the
case of a Restricted Note) in substantially the following form:

                  THIS NOTE IS A GLOBAL NOTE WITHIN THE MEANING OF THIS
         INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A
         DEPOSITORY OR A NOMINEE OF A DEPOSITORY OR A SUCCESSOR DEPOSITORY. THIS
         NOTE IS NOT EXCHANGEABLE FOR SECURITIES REGISTERED IN THE NAME OF A
         PERSON OTHER THAN THE DEPOSITORY OR ITS NOMINEE EXCEPT IN THE LIMITED
         CIRCUMSTANCES DESCRIBED IN THIS INDENTURE, AND NO TRANSFER OF THIS NOTE
         (OTHER THAN A TRANSFER OF THIS NOTE AS A WHOLE BY THE DEPOSITORY TO A
         NOMINEE OF THE DEPOSITORY OR BY A NOMINEE OF THE DEPOSITORY TO THE
         DEPOSITORY OR ANOTHER NOMINEE OF THE DEPOSITORY) MAY BE REGISTERED
         EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THIS INDENTURE.

                  UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED
         REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION
         ("DTC"), TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER,
         EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE
         NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN
         AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO.
         OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE
         OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
         OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED
         OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.




                                      B-1
<PAGE>   145


                                                                       EXHIBIT C



                            Form of Certificate To Be
                          Delivered in Connection with
                    Transfers to Non-QIB Accredited Investors


Verio Inc.
9250 East Costilla Avenue
Suite 400
Englewood, Colorado  80112

Ladies and Gentlemen:

           In connection with our proposed purchase of $ aggregate principal 
amount of the 10-3/8% Senior Notes Due 2005 (the "Notes" of Verio Inc. (the
"Company"), we confirm that:

               1. We understand that the Notes have not been registered under
     the Securities Act of 1933, as amended (the "Securities Act"), and, unless
     so registered, may not be sold except as permitted in the following
     sentence. We agree on our own behalf and on behalf of any investor account
     for which we are purchasing Notes to offer, sell or otherwise transfer such
     Notes prior to (x) the date which is two years (or such shorter period of
     time as permitted by Rule 144 under the Securities Act) after the later of
     the date of original issue of the Notes and (y) such later date, if any, as
     may be required by any subsequent change in applicable law (the "Resale
     Restriction Termination Date") only (a) to the Company, (b) pursuant to a
     registration statement which has been declared effective under the
     Securities Act, (c) so long as the Notes are eligible for resale pursuant
     to Rule 144A under the Securities Act, to a person we reasonably believe is
     a "qualified institutional buyer" under Rule 144A (a "QIB") that purchases
     for its own account or for the account of a QIB and to whom notice is given
     that the transfer is being made in reliance on Rule 144A, (d) pursuant to
     offers and sales that occur outside the United States to "foreign
     purchasers" (as defined below) in offshore transactions meeting the
     requirements of Rule 904 of Regulation S under the Securities Act, (e) to
     an institutional "accredited investor" within the meaning of subparagraph
     (a)(1), (2), (3) or (7) of Rule 501 under the Securities Act (an
     "Accredited Investor") that is purchasing for its own account or for the



                                      C-1
<PAGE>   146

     account of such an institutional "accredited investor," or (f) pursuant to
     any other available exemption from the registration requirements of the
     Securities Act, subject, in each of the foregoing cases, to any requirement
     of law that the disposition of our property or the property of such
     investor account or accounts be at all times within our or their control
     and to compliance with any applicable state securities laws. The foregoing
     restrictions on resale will not apply subsequent to the Resale Restriction
     Termination Date. If any resale or other transfer of the Notes is proposed
     to be made pursuant to clause (c) above prior to the Resale Restriction
     Termination Date, the transferor shall deliver a letter from the transferee
     substantially in the form of this letter to the Trustee, which shall
     provide, among other things, that the transferee is an Accredited Investor
     within the meaning of subparagraph (a)(1), (2), (3) or (7) of Rule 501
     under the Securities Act and that it is acquiring such Notes for investment
     purposes and not for distribution in violation of the Securities Act. Each
     purchaser acknowledges that the Company, the Trustee and the Transfer Agent
     and Registrar reserve the right prior to any offer, sale or other transfer
     prior to the Resale Restriction Termination Date of the Notes pursuant to
     clause (d), (e) or (f) above to require the delivery of an opinion of
     counsel, certification and/or other information satisfactory to the Company
     and the Trustee.

               2. We are an Accredited Investor or a QIB purchasing Notes for
     our own account or for the account of one or more Accredited Investors, and
     we are acquiring the Notes for investment purposes and not with a view to,
     or for offer or sale in connection with, any distribution in violation of
     the Securities Act or the securities laws of any state of the United States
     and we have such knowledge and experience in financial and business matters
     as to be capable of evaluating the merits and risks of our investment in
     the Notes, and we and any accounts for which we are acting are each able to
     bear the economic risk of our or its investment in the Notes for an
     indefinite period.

               3. We are acquiring the Notes purchased by us for our own account
     or for one or more accounts as to each of which we exercise sole investment
     discretion and we and any such account are (a) a QIB, aware that the sale
     is being made in reliance on Rule 144A under the Securities Act, (b) an
     Accredited Investor, or (c) a person other than a U.S. person ("foreign
     purchasers"), which term 


                                      C-2
<PAGE>   147

     shall include dealers or other professional fiduciaries in the United
     States acting on a discretionary basis for foreign beneficial owners (other
     than an estate or trust) in offshore transactions meeting the requirements
     of Rules 903 and 904 of Regulation S under the Securities Act.

               4. We have received a copy of the Offering Memorandum and
     acknowledge that we have had access to such financial and other
     information, and have been afforded the opportunity to ask such questions
     of representatives of the Company and receive answers thereto, as we deem
     necessary in order to verify the information contained in the Offering
     Memorandum.

               5. We are not purchasing the Notes for or on behalf of, and will
     not transfer the Notes to, any pension or welfare plan (as defined in
     Section 3 of ERISA, except as may be permitted under ERISA and as described
     under "Notice to Investors" in the Offering Memorandum.

               6. In the event that we purchase any Notes, we will acquire Notes
     having an outstanding principal amount of at least $250,000 for our own
     account and $250,000 for each account for which we are acting.

           We understand that the Trustee and the Transfer Agent will not be 
required to accept for registration of transfer any Notes acquired by us, except
upon presentation of evidence satisfactory to the Company and the Trustee that
the foregoing restrictions on transfer have been complied with. We further
understand that the Notes purchased by us will be in the form of definitive
physical certificates and that such certificates will bear a legend reflecting
the substance of this paragraph. We further agree to provide to any person
acquiring any of the Notes from us a notice advising such person that transfers
of such Notes are restricted as stated herein and that certificates representing
such Notes will bear a legend to that effect.

           We represent that you, the Company, the Trustee and others are 
entitled to rely upon the truth and accuracy of our acknowledgements,
representations and agreements set forth herein, and we agree to notify you
promptly in writing if any of our acknowledgements, representations or
agreements herein cease to be accurate and complete. You are also irrevocably
authorized to produce this letter or a copy hereof to any interested party in
any administrative or legal proceeding or official inquiry with respect to the
matters covered hereby.



                                      C-3
<PAGE>   148

           We represent to you that we have full power to make the foregoing 
acknowledgements, representations and agreements on our own behalf and on behalf
of any investor account for which we are acting as fiduciary agent.

           As used herein, the terms "offshore transaction," "United States" 
and "U.S. person" have the respective meanings given to them in Regulation S
under the Securities Act.

           THIS LETTER SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, 
THE LAWS OF THE STATE OF NEW YORK.

                                                    Very truly yours,


                                                    (Name of Purchaser)



By:
   ----------------------------------

Date:
     --------------------------------


           Upon transfer, the Notes would be registered in the name of the new
beneficial owner as follows:



Name:
     --------------------------------

Address:
        -----------------------------



                                      C-4
<PAGE>   149



                                                                       EXHIBIT D


                       Form of Certificate To Be Delivered
                          in Connection with Transfers
                            Pursuant to Regulation S


                                                         ________________ , ____


First Trust National Association
180 East 5th Street
St. Paul, Minnesota  55101
Attention:  Corporate Trust Department


                  Re:      Verio Inc.
                           (the "Company") 10-3/8% Senior Notes Due 2005
                           (the "Securities")

Ladies and Gentlemen:

                  In connection with our proposed sale of $ aggregate principal
amount of the Securities, we confirm that such sale has been effected pursuant
to and in accordance with Regulation S under the U.S. Securities Act of 1933, as
amended (the "Securities Act"), and, accordingly, we represent that:

                  (1) the offer of the Securities was not made to a person in 
         the United States;

                  (2) either (a) at the time the buy offer was originated, the
         transferee was outside the United States or we and any person acting on
         our behalf reasonably believed that the transferee was outside the
         United States, or (b) the transaction was executed in, on or through
         the facilities of a designated off-shore securities market and neither
         we nor any person acting on our behalf knows that the transaction has
         been pre-arranged with a buyer in the United States;

                  (3) no directed selling efforts have been made in the United
         States in contravention of the requirements of Rule 903(b) or Rule
         904(b) of Regulation S, as applicable;



                                      D-1
<PAGE>   150

                  (4) the transaction is not part of a plan or scheme to evade
         the registration requirements of the Securities Act;

                  (5) we have advised the transferee of the transfer 
         restrictions applicable to the Securities;

                  (6) if the circumstances set forth in Rule 904(c) under the
         Securities Act are applicable, we have complied with the additional
         conditions therein, including (if applicable) sending a confirmation or
         other notice stating that the Securities may be offered and sold during
         the restricted period specified in Rule 903(c)(2) or (3), as
         applicable, in accordance with the provisions of Regulation S; pursuant
         to registration of the Securities under the Securities Act; or pursuant
         to an available exemption from the registration requirements under the
         Securities Act; and

                  (7) if the sale is made during a restricted period and the
         provisions of Rule 903(c)(3) are applicable thereto, we confirm that
         such sale has been made in accordance with such provisions.

                  You and the Company are entitled to rely upon this letter and
are irrevocably authorized to produce this letter or a copy hereof to any
interested party in any administrative or legal proceedings or official inquiry
with respect to the matters covered hereby. Terms used in this certificate have
the meanings set forth in Regulation S.

                                                     Very truly yours,

                                                     [Name of Transferor]


                                                     By:
                                                        -----------------------
                                                        Authorized Signature




                                      D-2