Document:

<PAGE>   1
                                                                     Exhibit 4.2

                             XO COMMUNICATIONS, INC.

                                       TO

                    U.S. TRUST COMPANY, NATIONAL ASSOCIATION

                                     Trustee
                                     -------

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

                                    Indenture

                          Dated as of ___________, 20__

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

                                $_______________

                       ____% Subordinated Notes Due 20___

<PAGE>   2
                               Table of Contents

                             XO COMMUNICATIONS, INC.
                 Certain Sections of this Indenture relating to
                         Sections 310 through 318 of the
                          Trust Indenture Act of 1939:

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Trust Indenture                                                                                  Indenture
Act Section                                                                                       Section
<S>                                                                                             <C>
Section 310(a)(1).............................................................................      609
        (a)(2)................................................................................      609
        (a)(3)................................................................................      Not Applicable
        (a)(4)................................................................................      Not Applicable
        (b)...................................................................................      608, 610
Section 311(a)................................................................................      613
        (b)...................................................................................      613
Section 312(a)................................................................................      701, 702
        (b)...................................................................................      702
        (c)...................................................................................      702
Section 313(a)................................................................................      703
        (b)...................................................................................      703
        (c)...................................................................................      703
        (d)...................................................................................      703
Section 314(a)................................................................................      704, 1008
        (b)...................................................................................      Not Applicable
        (c)(1)................................................................................      102, 401, 1104
        (c)(2)................................................................................      102, 401, 1104
        (c)(3)................................................................................      Not Applicable
        (d)...................................................................................      Not Applicable
        (e)...................................................................................      102
Section 315(a)................................................................................      601
        (b)...................................................................................      602
        (c)...................................................................................      601, 603
        (d)...................................................................................      601
        (e)...................................................................................      514
Section 316(a)(1)(A)..........................................................................      512
        (a)(1)(B).............................................................................      513
        (a)(2)................................................................................      Not Applicable
        (b)...................................................................................      508
        (c)...................................................................................      104
Section 317(a)(1).............................................................................      503
        (a)(2)................................................................................      504
        (b)...................................................................................      1003
Section 318(a)................................................................................      107
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                                TABLE OF CONTENTS
                                  (continued)

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RECITALS OF THE COMPANY .........................................................................................1

                                                       ARTICLE ONE
                              DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

SECTION 101.               Definitions...........................................................................1
Act                        ......................................................................................2
Affiliate                  ......................................................................................2
Authenticating Agent       ......................................................................................2
Board of Directors         ......................................................................................2
Board Resolution           ......................................................................................2
Business Day               ......................................................................................2
Capital Stock              ......................................................................................2
Change of Control          ......................................................................................2
Commission                 ......................................................................................3
Company                    ......................................................................................3
Company Request or Company Order.................................................................................3
Corporate Trust Office     ......................................................................................3
Corporation                ......................................................................................3
Default                    ......................................................................................3
Defaulted Interest         ......................................................................................3
Depositary                 ......................................................................................3
Designated Senior Indebtedness...................................................................................3
DTC                        ......................................................................................4
Eagle River                ......................................................................................4
Event of Default           ......................................................................................4
Exchange Act               ......................................................................................4
Global Security            ......................................................................................4
Guarantee                  ......................................................................................4
Holder                     ......................................................................................4
Incur                      ......................................................................................4
Indebtedness               ......................................................................................4
Indenture                  ......................................................................................5
Interest Payment Date      ......................................................................................5
Junior Securities          ......................................................................................5
Material Subsidiary        ......................................................................................5
Maturity                   ......................................................................................5
Obligations                ......................................................................................6
Officers' Certificate      ......................................................................................6
Opinion of Counsel         ......................................................................................6
Outstanding                ......................................................................................6
Paying Agent               ......................................................................................6
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                                TABLE OF CONTENTS
                                  (continued)

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Payment Blockage Notice    ......................................................................................7
Person                     ......................................................................................7
Predecessor Security       ......................................................................................7
Redemption Date            ......................................................................................7
Redemption Price           ......................................................................................7
Regular Record Date        ......................................................................................7
SEC Reports                ......................................................................................7
Securities                 ......................................................................................7
Securities Act             ......................................................................................7
Security Register          ......................................................................................7
Senior Indebtedness        ......................................................................................7
Special Record Date        ......................................................................................8
Stated Maturity            ......................................................................................8
Subsidiary                 ......................................................................................8
Trust Indenture Act        ......................................................................................8
Trustee                    ......................................................................................8
U.S. Government Obligation ......................................................................................8
Vice President             ......................................................................................8
Voting Stock               ......................................................................................8
SECTION 102.               Compliance Certificates and Opinions..................................................8
SECTION 103.               Form of Documents Delivered to Trustee................................................9
SECTION 104.               Acts of Holders; Record Dates........................................................10
SECTION 105.               Notices, Etc., to Trustee and Company................................................12
SECTION 106.               Notice to Holders; Waiver............................................................12
SECTION 107.               Application of Trust Indenture Act...................................................13
SECTION 108.               Effect of Headings and Table of Contents.............................................13
SECTION 109.               Successors and Assigns...............................................................13
SECTION 110.               Separability Clause..................................................................13
SECTION 111.               Benefits of Indenture................................................................13
SECTION 112.               Governing Law........................................................................13
SECTION 113.               Legal Holidays.......................................................................13

                                                   ARTICLE TWO
                                                 SECURITIES FORMS

SECTION 201.               Forms Generally......................................................................14
SECTION 202.               [Intentionally omitted]..............................................................14
SECTION 203.               [Intentionally omitted]..............................................................14
SECTION 204.               Additional Provisions Required in Global Security....................................14
SECTION 205.               Form of Trustee's Certificate of Authentication......................................15
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                                TABLE OF CONTENTS
                                  (continued)

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                                                   ARTICLE THREE
                                                  THE SECURITIES

SECTION 301.               Amount Unlimited; Issuable in Series.................................................15
SECTION 302.               Denominations........................................................................18
SECTION 303.               Execution, Authentication, Delivery and Dating.......................................18
SECTION 304.               Temporary Securities.................................................................19
SECTION 305.               Registration, Registration of Transfer and Exchange..................................19
SECTION 306.               Mutilated, Destroyed, Lost and Stolen Securities.....................................21
SECTION 307.               Payment of Interest; Interest Rights Preserved.......................................22
SECTION 308.               Persons Deemed Owners................................................................23
SECTION 309.               Cancellation.........................................................................23
SECTION 310.               Computation of Interest..............................................................23

                                                   ARTICLE FOUR
                                           SATISFACTION AND DISCHARGE

SECTION 401.               Satisfaction and Discharge of Indenture..............................................23
SECTION 402.               Application of Trust Money...........................................................25

                                                   ARTICLE FIVE
                                                     REMEDIES

SECTION 501.               Events of Default....................................................................25
SECTION 502.               Acceleration of Maturity; Rescission and Annulment...................................27
SECTION 503.               Collection of Indebtedness and Suits for Enforcement by Trustee......................28
SECTION 504.               Trustee May File Proofs of Claim.....................................................28
SECTION 505.               Trustee May Enforce Claims Without Possession of Securities..........................29
SECTION 506.               Application of Money Collected.......................................................29
SECTION 507.               Limitation on Suits..................................................................29
SECTION 508.               Unconditional Right of Holders to Receive Principal, Premium and Interest............30
SECTION 509.               Restoration of Rights and Remedies...................................................30
SECTION 510.               Rights and Remedies Cumulative.......................................................30
SECTION 511.               Delay or Omission Not Waiver.........................................................31
SECTION 512.               Control by Holders...................................................................31
SECTION 513.               Waiver of Past Defaults..............................................................31
SECTION 514.               Undertaking for Costs................................................................32
SECTION 515.               Waiver of Stay or Extension Laws.....................................................32

                                                   ARTICLE SIX
                                                   THE TRUSTEE

SECTION 601.               Certain Duties and Responsibilities..................................................32
SECTION 602.               Notice of Defaults...................................................................32
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                                TABLE OF CONTENTS
                                  (continued)

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SECTION 603.               Certain Rights of Trustee............................................................33
SECTION 604.               Not Responsible for Recitals or Issuance of Securities...............................34
SECTION 605.               May Hold Securities..................................................................34
SECTION 606.               Money Held in Trust..................................................................34
SECTION 607.               Compensation and Reimbursement.......................................................34
SECTION 608.               Disqualification; Conflicting Interests..............................................35
SECTION 609.               Corporate Trustee Required; Eligibility..............................................35
SECTION 610.               Resignation and Removal; Appointment of Successor....................................35
SECTION 611.               Acceptance of Appointment by Successor...............................................37
SECTION 612.               Merger, Conversion, Consolidation or Succession to Business..........................38
SECTION 613.               Preferential Collection of Claims Against the Company................................38
SECTION 614.               Appointment of Authenticating Agent..................................................38

                                                   ARTICLE SEVEN
                                   HOLDERS' LISTS AND REPORTS BY TRUSTEE AND THE COMPANY

SECTION 701.               Company to Furnish Trustee Names and Addresses of Holders............................40
SECTION 702.               Preservation of Information; Communications to Holders...............................40
SECTION 703.               Reports by Trustee...................................................................41
SECTION 704.               Reports by Company...................................................................41

                                                   ARTICLE EIGHT
                                            MERGER, CONSOLIDATION, ETC

SECTION 801.               Mergers, Consolidations and Certain Sales of Assets..................................41
SECTION 802.               Successor Substituted................................................................42

                                                   ARTICLE NINE
                                              SUPPLEMENTAL INDENTURES

SECTION 901.               Supplemental Indentures Without Consent of Holders...................................42
SECTION 902.               Supplemental Indentures with Consent of Holders......................................43
SECTION 903.               Execution of Supplemental Indentures.................................................44
SECTION 904.               Effect of Supplemental Indentures....................................................45
SECTION 905.               Conformity with Trust Indenture Act..................................................45
SECTION 906.               Reference in Securities to Supplemental Indentures...................................45

                                                   ARTICLE TEN
                                                    COVENANTS

SECTION 1001.              Payment of Principal, Premium and Interest...........................................45
SECTION 1002.              Maintenance of Office or Agency......................................................45
SECTION 1003.              Money for Security Payments to be Held in Trust......................................46
SECTION 1004.              Existence............................................................................47
SECTION 1005.              Maintenance of Properties............................................................47
SECTION 1006.              Provision of Financial Information...................................................48
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                                TABLE OF CONTENTS
                                  (continued)

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SECTION 1007.              [Intentionally deleted]..............................................................48
SECTION 1008.              Statement by Officers as to Default..................................................48
SECTION 1009.              Waiver of Certain Covenants and Obligations..........................................48

                                                   ARTICLE ELEVEN
                                        DEFEASANCE AND COVENANT DEFEASANCE

SECTION 1101.              Company's Option to Effect Defeasance or Covenant Defeasance.........................48
SECTION 1102.              Defeasance and Discharge.............................................................49
SECTION 1103.              Covenant Defeasance..................................................................49
SECTION 1104.              Conditions to Defeasance or Covenant Defeasance......................................50
SECTION 1105.              Deposited Money and U.S. Government Obligations to Be Held in Trust;
                           Other Miscellaneous Provisions ......................................................52
SECTION 1106.              Reinstatement........................................................................52
SECTION 1107.              Repayment to Company.................................................................52

                                                   ARTICLE TWELVE
                                              [INTENTIONALLY DELETED]

                                                   ARTICLE THIRTEEN
                                              [INTENTIONALLY DELETED]

                                                   ARTICLE FOURTEEN
                                             [INTENTIONALLY DELETED]

                                                   ARTICLE FIFTEEN
                                           SUBORDINATION OF SECURITIES

SECTION 1501.              Securities Subordinated to Senior Indebtedness.......................................53
SECTION 1502.              No Payment on Securities in Certain Circumstances....................................54
SECTION 1503.              Securities Subordinated to Prior Payment of All Senior Indebtedness
                           on Dissolution, Liquidation or Reorganization........................................55
SECTION 1504.              Securityholders to Be Subrogated to Rights of Holders of Senior Indebtedness.........56
SECTION 1505.              Obligations of the Company Unconditional.............................................56
SECTION 1506.              Trustee Entitled To Assume Payments Not Prohibited in Absence of Notice..............57
SECTION 1507.              Application by Trustee of Assets Deposited with It...................................57
SECTION 1508.              Subordination Rights Not Impaired by Acts or Omissions of the Company
                           or Holders of Senior Indebtedness....................................................57
SECTION 1509.              Securityholders Authorize Trustee to Effectuate Subordination of Securities..........58
SECTION 1510.              Right of Trustee to Hold Senior Indebtedness.........................................58
SECTION 1511.              Article Fifteen Not to Prevent Events of Default.....................................58
SECTION 1512.              No Fiduciary Duty of Trustee to Holders of Senior Indebtedness.......................58
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                                TABLE OF CONTENTS
                                  (continued)

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                                                   ARTICLE SIXTEEN
                                               REDEMPTION OF SECURITIES

SECTION 1601.              Applicability of Article.............................................................59
SECTION 1602.              Election to Redeem; Notice to Trustee................................................59
SECTION 1603.              Selection by Trustee of Securities to Be Redeemed....................................59
SECTION 1604.              Notice of Redemption.................................................................60
SECTION 1605.              Deposit of Redemption Price..........................................................60
SECTION 1606.              Securities Payable on Redemption Date................................................61
SECTION 1607.              Securities Redeemed in Part..........................................................61
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<PAGE>   9

       INDENTURE, dated as of _____________, 200__, between XO COMMUNICATIONS,
INC., a Delaware corporation (hereinafter called the "Company"), having its
principal office at 11111 Sunset Hills Drive, Reston, VA 20190 and U.S. Trust
Company, National Association, a corporation duly authorized and existing under
the laws of the United States, as Trustee hereunder (hereinafter called the
"Trustee").

                             RECITALS OF THE COMPANY

       The Company has duly authorized the execution and delivery of this
Indenture to provide for the issuance from time to time of its unsecured
debentures, notes or other evidences of indebtedness (herein called the
"Securities"), to be issued in one or more series as provided in this Indenture.
The Securities shall be subordinate in right of payment to the existing and
future Senior Indebtedness (as hereinafter defined) of the Company to the extent
provided in Article Fifteen of this Indenture.

       This Indenture is subject to the provisions of the Trust Indenture Act of
1939, as amended, that are deemed to be incorporated into this Indenture and
shall, to the extent applicable, be governed by such provisions.

       All things necessary to make this Indenture a valid agreement of the
Company, in accordance with its terms, have been done.

       NOW, THEREFORE, THIS INDENTURE WITNESSETH:

       For and in consideration of the premises and the purchase of the
Securities by the Holders thereof, it is mutually agreed, for the equal and
proportionate benefit of all Holders of the Securities or of series thereof, as
follows:

                                  ARTICLE ONE

             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

       SECTION 101 Definitions.

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

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

              (2) 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;

              (3) all accounting terms not otherwise defined herein have the
       meanings assigned to them in accordance with generally accepted
       accounting principles (whether or not such is indicated herein) and,
       except as otherwise herein expressly provided, the term "GAAP" or
       "generally accepted accounting principles" with respect to any
       computation required

<PAGE>   10

       or permitted hereunder shall mean such accounting principles as are
       generally accepted as consistently applied by the Company at the date of
       such computation; and

              (4) 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.

       Certain terms, used principally in Article Six, are defined in that
Article.

       "Act", when used with respect to any Holder, has the meaning specified in
Section 104.

       "Affiliate" of any specified Person means any other Person directly or
indirectly controlling or controlled by or under direct or indirect common
control with such specified Person. For the purposes of this definition,
"control" when used with respect to any specified 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 "controlling" and "controlled" have meanings correlative to the
foregoing.

       "Authenticating Agent" has the meaning set forth in Section 614 hereof.

       "Board of Directors" means either the board of directors of the Company
or any duly authorized committee of that Board.

       "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 of Directors 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 Borough of Manhattan,
The City of New York, New York are authorized or obligated by law or executive
order to close.

       "Capital Stock" of any Person means any and all shares, interests,
participations or other equivalents (however designated) of corporate stock or
other equity participations, including partnership interests, whether general or
limited, of such Person.

       A "Change of Control" will be deemed to have occurred at such time as
either:

              (1)    any Person or any Persons acting together that would
constitute a "group" for purposes of Section 13(d) of the Exchange Act, or any
successor provision thereto (other than Eagle River, Mr. Craig O. McCaw and
their respective Affiliates or an underwriter engaged in a firm commitment
underwriting on behalf of the Company), shall beneficially own (within the
meaning of Rule 13d-3 under the Exchange Act, or any successor provision
thereto) more than 50% of the aggregate voting power of all classes of Voting
Stock of the Company; or

              (2)    neither Mr. Craig O. McCaw nor any person designated by him
to the Company as acting on his behalf shall be a director of the Company; or

                                       2
<PAGE>   11

              (3)    during any period of two consecutive years, individuals who
at the beginning of such period constituted the Board of Directors (together
with any new directors whose election by the Board of Directors or whose
nomination for election by the shareholders of the Company was proposed by a
vote of a majority of the directors of the Company 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 to constitute a
majority of the Board of Directors then in office.

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

       "Company" means the Person named as the "Company" in the first paragraph
of this instrument 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 (i) the Chief Executive Officer, the
President, an Executive Vice President or a Vice President of the Company, and
(ii) the Treasurer, Assistant Treasurer, Secretary or an Assistant Secretary of
the Company, and delivered to the Trustee.

       "Corporate Trust Office" means the principal office of U.S. Trust
Company, National Association in the Borough of Manhattan, The City of New York,
New York, at which at any particular time its corporate trust business shall be
administered, which on the date hereof is located at 114 West 47th Street, New
York, New York 10036.

       "Corporation" means a corporation, association, company, limited
liability company, joint-stock company or business trust.

       "Default" means an event that with the passing of time or the giving of
notice or both shall constitute an Event of Default.

       "Defaulted Interest" has the meaning set forth in Section 307 hereof.

       "Depositary" means, with respect to the Securities of any series issuable
or issued in whole or in part in the form of one or more Global Securities, DTC
for so long as it shall be a clearing agency registered under the Exchange Act,
or such successor (which shall be a clearing agency registered under the
Exchange Act) as the Company shall designate from time to time in an Officers'
Certificate delivered to the Trustee.

       "Designated Senior Indebtedness" means obligations of the Company under
any particular Senior Indebtedness in respect of which the instrument creating
or evidencing the same or the assumption or guarantee thereof, or related
agreements or documents to which the Company is a party, expressly provides that
such indebtedness shall be Designated Senior Indebtedness for purposes of the
Indenture. The instrument, agreement or other document evidencing any Designated
Senior Indebtedness may place limitations and conditions on the right of such
Senior Indebtedness to exercise the rights of Designated Senior Indebtedness.

                                       3
<PAGE>   12

       "DTC" means The Depository Trust Company.

       "Eagle River" means Eagle River Investments, L.L.C., a limited liability
company formed under the laws of the State of Washington.

       "Event of Default" has the meaning specified in Section 501.

       "Exchange Act" means the Securities Exchange Act of 1934, as amended (or
any successor act) and the rules and regulations thereunder.

       "Global Security" means a Security of any series in the form prescribed
in Section 204 and as contemplated by Section 301 evidencing all or part of the
Securities of any series, issued to the Depositary or its nominee, and
registered in the name of such Depositary or its nominee.

       "Guarantee" by any Person means any obligation, contingent or otherwise,
of such Person guaranteeing, or having the economic effect of guaranteeing, any
Indebtedness of any other Person (the "primary obligor") in any manner, whether
directly or indirectly, and including, without limitation, any obligation of
such Person,

       (i) to purchase or pay (or advance or supply funds for the purchase or
payment of) such Indebtedness or to purchase (or to advance or supply funds for
the purchase of) any security for the payment of such Indebtedness,

       (ii) to purchase property, securities or services for the purpose of
assuring the holder of such Indebtedness of the payment of such Indebtedness, or

       (iii) to maintain working capital, equity capital or other financial
statement condition or liquidity of the primary obligor so as to enable the
primary obligor to pay such Indebtedness (and "Guaranteed", "Guaranteeing" and
"Guarantor" shall have meanings correlative to the foregoing); provided,
however, that the Guarantee by any Person shall not include endorsements by such
Person for collection or deposit, in either case, in the ordinary course of
business.

       "Holder" means a Person in whose name a Security is registered in the
Security 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 generally accepted accounting principles 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).

       "Indebtedness" means, with respect to any Person, all Obligations,
whether or not contingent, of such Person (i)(a) for borrowed money (including,
but not limited to, any indebtedness secured by a security interest, mortgage or
other lien on the assets of the Company that is (1) given to secure all or part
of the purchase price of property subject thereto, whether given to the vendor
of such property or to another, or (2) existing on property at the time of
acquisition thereof), (b) evidenced by a note, debenture, bond or other written
instrument,

                                       4
<PAGE>   13

(c) under a lease required to be capitalized on the balance sheet of the lessee
under GAAP or under any lease or related document (including a purchase
agreement) that provides that the Company is contractually obligated to purchase
or cause a third party to purchase and thereby guarantee a minimum residual
value of the lease property to the lessor and the Company's obligations under
such lease or related document to purchase or to cause a third party to purchase
such leased property, (d) in respect of letters of credit, bank guarantees or
bankers' acceptances (including reimbursement obligations with respect to any of
the foregoing), (e) with respect to indebtedness secured by a mortgage, pledge,
lien, encumbrance, charge or adverse claim affecting title or resulting in an
encumbrance to which the property or assets of such Person are subject, whether
or not the obligation secured thereby shall have been assumed by or shall
otherwise be such Person's legal liability, (f) in respect of the balance of
deferred and unpaid purchase price of any property or assets, (g) under interest
rate or currency swap agreements, cap, floor and collar agreements, spot and
forward contracts and similar agreements and arrangements; (ii) with respect to
any obligation of others of the type described in the preceding clause (i) or
under clause (iii) below assumed by or guaranteed in any manner by such person
or in effect guaranteed by such person through an agreement to purchase
(including, without limitation, "take or pay" and similar arrangements),
contingent or otherwise (and the obligations of such person under any such
assumptions, guarantees or other such arrangements); and (iii) any and all
deferrals, renewals, extensions, refinancings and refundings of, or amendments,
modifications or supplements to, any of the foregoing.

       "Indenture" means this instrument as originally executed 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,
including, for all purposes of this instrument and any such supplemental
indenture, the provisions of the Trust Indenture Act that are deemed to be a
part of and govern this instrument and any such supplemental indenture,
respectively. The term "Indenture" shall also include the terms of particular
series of Securities established as contemplated by Section 301.

       "Interest Payment Date" when used with respect to any installment of
interest on a Security of any series means the date specified in such Security
on which such installment of interest is due and payable.

       "Junior Securities" means any Indebtedness of the Company that is at
least as subordinated in right of payment to Senior Indebtedness as the
Securities and has no scheduled installment of principal due, by redemption,
sinking fund payment or otherwise, on or prior to the Stated Maturity of the
Securities.

       "Material Subsidiary" means, as of any date of determination, a
Subsidiary that is a "significant subsidiary" as defined in Rule 1-02(w) of
Regulation S-X under the Securities Act and the Exchange Act.

       "Maturity", when used with respect to any Security, means the date on
which the principal of such Security or an installment of principal becomes due
and payable as therein or herein provided, whether at the Stated Maturity, by
declaration of acceleration, upon required repurchase or call for redemption or
otherwise.

                                       5
<PAGE>   14

       "Obligations" means, with respect to any Indebtedness, any principal,
interest, penalties, fees, indemnifications, reimbursements, damages or other
liabilities payable under the documentation governing such Indebtedness.

       "Officers' Certificate" means a certificate signed by (i) the Chief
Executive Officer, President, an Executive Vice President or a Vice President,
and (ii) the Treasurer, Assistant Treasurer, Secretary or an Assistant
Secretary, of the Company, and delivered to the Trustee and containing the
statements provided for in Section 102. One of the officers signing an Officers'
Certificate given pursuant to Section 1008 shall be the principal executive,
financial or accounting officer of the Company.

       "Opinion of Counsel" means a written opinion of legal counsel, who may be
counsel for the Company, and who shall be acceptable to the Trustee, and
containing the statements provided for in Section 102.

       "Outstanding", when used with respect to Securities of any series, means,
as of the date of determination, all Securities of that series theretofore
authenticated and delivered under this Indenture, except:

       (i) Securities theretofore cancelled by the Trustee or delivered to the
Trustee for cancellation;

       (ii) Securities for whose payment or redemption money in the necessary
amount has been theretofore deposited with the Trustee or any Paying Agent
(other than the Company) in trust or set aside and segregated in trust by the
Company (if the Company shall act as its own Paying Agent) for the Holders of
such Securities; provided that, if such Securities 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; and

       (iii) Securities which have been paid pursuant to Section 306 or in
exchange for or in lieu of which other Securities have been authenticated and
delivered pursuant to this Indenture, other than any such Securities of that
series in respect of which there shall have been presented to the Trustee proof
satisfactory to it that such Securities are held by a bona fide purchaser in
whose hands such Securities are valid obligations of the Company;

provided, however, that in determining whether the Holders of the requisite
principal amount of Outstanding Securities have given any request, demand,
authorization, direction, notice, consent or waiver hereunder, Securities owned
by the Company or any other obligor upon the Securities or any Affiliate of the
Company or of 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 Securities which the Trustee knows to be so owned shall
be so disregarded. Securities 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 Securities and that
the pledgee is not the Company or any other obligor upon the Securities or any
Affiliate of the Company or of such other obligor.

       "Paying Agent" means any Person authorized by the Company to pay the
principal of (and premium, if any) or interest on any Securities on behalf of
the Company. The Trustee is

                                       6
<PAGE>   15

hereby authorized by the Company to act as a "Paying Agent" for the purposes of
this Indenture, until such time as the Company notifies the Trustee in writing
that such authorization is revoked.

       "Payment Blockage Notice" has the meaning set forth in Section 1502
hereof.

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

       "Predecessor Security" of any particular Security means every previous
Security issued before, and evidencing all or a portion of the same debt as that
evidenced by, such particular Security; and, for the purposes of this
definition, any Security authenticated and delivered under Section 306 in
exchange for or in lieu of a mutilated, destroyed, lost or stolen Security shall
be deemed to evidence the same debt as the mutilated, destroyed, lost or stolen
Security.

       "Redemption Date", when used with respect to any Security to be redeemed,
means the date fixed for such redemption by or pursuant to this Indenture.

       "Redemption Price", when used with respect to any Security to be
redeemed, means the price at which it is to be redeemed pursuant to this
Indenture.

       "Regular Record Date" for the interest payable on any Interest Payment
Date on the Securities of any series means the date specified for that purpose
as contemplated by Section 301.

       "Required Consent" means, except as otherwise expressly provided in this
Indenture with respect to matters requiring the consent of each Holder of
Securities affected thereby: (i) the consent of Holders of not less than a
majority in aggregate principal amount at Stated Maturity of Securities of any
series for any action relating to that series to (x) direct the time, method and
place of conducting any proceeding for any remedy available to the Trustee, or
exercising any power conferred upon such Trustee, or (y) consent to or waive, on
behalf of the Holders of all the Securities of that series, any past default and
its consequences, and (ii) with respect to all other actions requiring the
consent of Holders of Securities of any series, the consent of either (x) the
Holders of a majority in aggregate principal amount at Stated Maturity of the
Securities of that series or, (y) voting together as a single class, the Holders
of a majority in aggregate principal amount at Stated Maturity of (I) the
Securities of that series, (II) the Securities of each other series whose
Holders are being requested to consent to such action with respect to the terms
of that series or this Indenture, (III) the securities of each series issued
under the Indenture filed as Exhibit 4.1 to the Company's Registration Statement
on Form S-3 (Reg. No. 333-_____), filed with the Commission on February 1, 2001,
if the holders of such securities are being requested to consent to such action
with respect to the terms of such series or that Indenture, and (IV) any other
class of debt securities issued by the Company, if such debt securities or the
indenture pursuant to which such debt securities were issued both (A) require
the consent of the holders of such debt securities to such action and (B)
provide that the holders thereof will vote with the Holders of Securities of any
series with respect to such action.

       "SEC Reports" has the meaning specified in Section 704.

       "Securities" has the meaning set forth in the recitals.

       "Securities Act" means the Securities Act of 1933 and any statute
successor thereto, in each case as amended from time to time.

                                       7
<PAGE>   16

       "Security Register" and "Security Registrar" have the respective meanings
specified in Section 305.

       "Senior Indebtedness" means the principal of, and interest on, rent
under, and any other amounts payable on or in or in respect of any Indebtedness
of the Company (including, without limitation, any Obligations in respect of
such Indebtedness and, in the case of Designated Senior Indebtedness, any
interest accruing after the filing of a petition by or against the Company under
any bankruptcy law, whether or not allowed as a claim after such filing in any
proceeding under such bankruptcy law), whether outstanding on the date hereof or
hereafter created, Incurred, assumed, Guaranteed or in effect Guaranteed by the
Company (including all deferrals, renewals, extensions or refundings of, or
amendments, modifications or supplements to the foregoing); provided, however,
that Senior Indebtedness does not include (v) Indebtedness evidenced by the
Securities, (w) any liability for federal, state, local or other taxes owed or
owing by the Company, (x) Indebtedness of the Company to any Subsidiary except
to the extent such Indebtedness is of a type described in clause (ii) of the
definition of Indebtedness, (y) trade payables of the Company for goods,
services or materials purchased in the ordinary course of business (other than,
to the extent they may otherwise constitute such trade payables, any obligations
of the type described in clause (viii) of the definition of Indebtedness), and
(z) any particular Indebtedness in which the instrument creating or evidencing
the same expressly provides that such Indebtedness shall not be senior in right
of payment to, or is pari passu with, or is subordinated or junior to, the
Securities.

       "Special Record Date" for the payment of any Defaulted Interest means a
date fixed by the Trustee pursuant to Section 307.

       "Stated Maturity", when used with respect to any Security or any
installment of principal thereon, means the date specified in such Security as
the fixed date on which the principal of such Security or such installment of
principal is due and payable.

       "Subsidiary" of any Person means

       (i) a corporation more than 50% of the combined voting power of the
outstanding Voting Stock of which is owned, directly or indirectly, by such
Person or by one or more other Subsidiaries of such Person or by such Person and
one or more Subsidiaries thereof or

       (ii) any other Person (other than a corporation) in which such Person, or
one or more other Subsidiaries of such Person or such Person and one or more
other Subsidiaries thereof, directly or indirectly, has at least a majority
ownership and power to direct the policies, management and affairs thereof.

       "Trust Indenture Act" means the Trust Indenture Act of 1939 as in force
at the date as of which this instrument was executed; provided, however, that in
the event the Trust Indenture Act of 1939 is amended after such date, "Trust
Indenture Act" means, to the extent required by any such amendment, the Trust
Indenture Act of 1939 as so amended.

       "Trustee" means the Person named as the "Trustee" in the first paragraph
of this instrument until one or more successor Trustees shall have become such
pursuant to the applicable provisions of this Indenture, and thereafter
"Trustee" shall mean such successor Trustee or Trustees.

                                       8
<PAGE>   17

       "U.S. Government Obligation" has the meaning specified in Section 1104.

       "Vice President", when used with respect to the Company or the Trustee,
means any vice president, whether or not designated by a number or a word or
words added before or after the title "vice president".

       "Voting Stock" of any Person means Capital Stock of such Person which
ordinarily has voting power for the election of directors (or persons performing
similar functions) of such Person, whether at all times or only so long as no
senior class of securities has such voting power by reason of any contingency.

       SECTION 102. 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 shall furnish to the
Trustee such certificates and opinions as may be required under the Trust
Indenture Act and under this Indenture. Each such certificate or opinion shall
be given in the form of an Officers' Certificate, if to be given by an officer
of the Company, or an Opinion of Counsel, if to be given by counsel, and shall
comply with the requirements of the Trust Indenture Act and any other
requirement set forth in this Indenture.

       Every certificate or opinion with respect to compliance with a condition
or covenant provided for in this Indenture (except for certificates provided for
in Section 1008 shall include

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

              (2) 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;

              (3) 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 or not such covenant or
       condition has been complied with; and

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

       SECTION 103. 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 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 such Persons as to other matters, and any such Person may certify
or give an opinion as to such matters in one or several documents.

                                       9
<PAGE>   18

       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 of counsel 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 and
form one instrument.

       SECTION 104. Acts of Holders; Record Dates.

       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 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 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 601) conclusive in favor of the Trustee and the Company,
if made in the manner provided in this Section.

       The fact and date of the execution by any Person of any such instrument
or writing pursuant to this Section 104 may be proved by the affidavit of a
witness of such execution or by a certificate of a notary public or other
officer authorized by law to take acknowledgments of deeds, certifying that the
individual signing such instrument or writing acknowledged to him the execution
thereof. Where such execution is by a signer acting in a capacity other than his
individual capacity, such certificate or affidavit shall also constitute
sufficient proof of his authority. The fact and date of the execution of any
such instrument or writing, or the authority of the Person executing the same,
may also be proved in any other manner which the Trustee deems sufficient.

       The ownership of Securities shall be proved by the Security Register.

                                       10
<PAGE>   19

       Any request, demand, authorization, direction, notice, consent, waiver or
other Act of the Holder of any Security shall bind every future Holder of the
same Security and the Holder of every Security issued upon the registration of
transfer thereof or in exchange therefor or in lieu thereof in respect of
anything done, omitted or suffered to be done by the Trustee or the Company in
reliance thereon, whether or not notation of such action is made upon such
Security.

       The Company may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities of any series entitled to
give, make or take any request, demand, authorization, direction, notice,
consent, waiver or other action provided or permitted by this Indenture to be
given, made or taken by Holders of Securities of such series, provided that the
Company may not set a record date for, and the provisions of this paragraph
shall not apply with respect to, the giving or making of any notice,
declaration, request or direction referred to in the next paragraph. If not set
by the Company prior to the first solicitation of a Holder made by any Person in
respect of any such matter referred to in the foregoing sentence, the record
date for any such matter shall be the 30th day (or, if later, the date of the
most recent list of Holders required to be provided pursuant to Section 701)
prior to such first solicitation. If any record date is set pursuant to this
paragraph, the Holders of Outstanding Securities of the relevant series on such
record date, and no other Holders, shall be entitled to take the relevant
action, whether or not such Holders remain Holders after such record date;
provided that no such action shall be effective hereunder unless taken on or
prior to the applicable expiration date by Holders of the requisite principal
amount of Outstanding Securities of the relevant series on such record date.
Nothing in this paragraph shall be construed to prevent the Company from setting
a new record date for any action for which a record date has previously been set
pursuant to this paragraph (whereupon the record date previously set shall
automatically and with no action by any Person be cancelled and of no effect),
and nothing in this paragraph shall be construed to render ineffective any
action taken by Holders of the requisite principal amount of Outstanding
Securities of the relevant series on the date such action is taken. Promptly
after any record date is set pursuant to this paragraph, the Company, at its own
expense, shall cause notice of such record date, the proposed action by Holders
and the applicable expiration date to be given to the Trustee in writing and to
each Holder of Securities of the relevant series in the manner set forth in
Section 106.

       The Trustee may set any day as a record date for the purpose of
determining the Holders of Outstanding Securities of any series entitled to join
in the giving or making of (i) any Notice of Default, (ii) any declaration of
acceleration referred to in Section 502, (iii) any request to institute
proceedings referred to in Section 507(2), (iv) any direction referred to in
Section 512 in each case with respect to Securities of such series or (v) the
Required Consent. If any record date is set pursuant to this paragraph, the
Holders of Outstanding Securities of such series on such record date, and no
other Holders, shall be entitled to join in such notice, declaration, request or
direction, whether or not such Holders remain Holders after such record date;
provided that no such action shall be effective hereunder unless taken on or
prior to the applicable expiration date by Holders of the requisite principal
amount of Outstanding Securities of such series on such record date. Nothing in
this paragraph shall be construed to prevent the Trustee from setting a new
record date for any action for which a record date has previously been set
pursuant to this paragraph (whereupon the record date previously set shall
automatically and with no action by any Person be cancelled and of no effect),
and nothing in this paragraph shall be construed to render ineffective any
action taken by Holders of the requisite principal amount

                                       11
<PAGE>   20

of Outstanding Securities of the relevant series on the date such action is
taken. Promptly after any record date is set pursuant to this paragraph, the
Trustee, at the Company's expense, shall cause notice of such record date, the
proposed action by Holders and the applicable expiration date to be given to the
Company in writing and to each Holder of Securities of the relevant series in
the manner set forth in Section 106.

       With respect to any record date set pursuant to this Section, the party
hereto which sets such record dates may designate any day as the "expiration
date" and from time to time may change the expiration date to any earlier or
later day; provided that no such change shall be effective unless notice of the
proposed new expiration date is given to the other party hereto in writing, and
to each Holder of Securities of the relevant series in the manner set forth in
Section 106, on or prior to the existing expiration date. If an expiration date
is not designated with respect to any record date set pursuant to this Section,
the party hereto which set such record date shall be deemed to have initially
designated the 180th day after such record date as the expiration date with
respect thereto, subject to its right to change the expiration date as provided
in this paragraph. Notwithstanding the foregoing, no expiration date shall be
later than the 180th day after the applicable record date.

       Without limiting the foregoing, a Holder entitled hereunder to take any
action hereunder with regard to any particular Security may do so with regard to
all or any part of the principal amount of such Security or by one or more duly
appointed agents each of which may do so pursuant to such appointment with
regard to all or any part of such principal amount.

       SECTION 105. Notices, Etc., to Trustee and 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,

              (1) the Trustee by any Holder or by the Company shall be
       sufficient for every purpose hereunder if delivered in writing to the
       Trustee at its Corporate Trust Office, Attention: Corporate Trust
       Administration, or

              (2) the Company by the Trustee or by any Holder shall be
       sufficient for every purpose hereunder (unless otherwise herein expressly
       provided) if in writing and mailed, first-class postage prepaid, to the
       Company addressed to the Company at the address of its principal office
       specified in the first paragraph of this instrument or at any other
       address previously furnished in writing to the Trustee by the Company.

       SECTION 106. Notice to Holders; Waiver.

       Where this Indenture provides for notice to Holders of any event, such
notice shall be sufficiently given (unless otherwise herein expressly provided)
if (i) in the case of a Global Security, in writing by facsimile and/or by
overnight mail to the Depositary, and (ii) in the case of Securities other than
Global Securities, in writing and mailed, first-class postage prepaid, to each
Holder affected by such event, at his address as it appears in the Security
Register, not later than the latest date (if any), and not earlier than the
earliest date (if any), prescribed for the giving of such notice. In any case
where notice to Holders is given by mail, neither the failure to

                                       12
<PAGE>   21

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. 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 give such notice by mail, then
such notification as shall be made with the approval of the Trustee shall
constitute a sufficient notification for every purpose hereunder.

       SECTION 107. Application of Trust Indenture Act.

       The Trust Indenture Act shall apply as a matter of contract to this
Indenture for purposes of interpretation, construction and defining the rights
and obligations hereunder. If any provision hereof limits, qualifies or
conflicts with a provision of the Trust Indenture Act that is required under
such Act to be a part of and govern this Indenture, the latter provision 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 to be
excluded, as the case may be.

       SECTION 108. 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.

       SECTION 109. 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 110. Separability Clause.

       In case any provision in this Indenture or in the Securities 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 111. Benefits of Indenture.

       Nothing in this Indenture or in the Securities, express or implied, shall
give to any Person, other than the parties hereto and their successors
hereunder, the Holders of Securities and, as to Article Fifteen hereof, the
holders of Senior Indebtedness, any benefit or any legal or equitable right,
remedy or claim under this Indenture.

                                       13
<PAGE>   22

       SECTION 112. Governing Law.

       This Indenture and the Securities shall be governed by and construed in
accordance with the laws of the State of New York.

       SECTION 113. Legal Holidays.

       In any case where any Interest Payment Date, Redemption Date or Stated
Maturity of any Security shall not be a Business Day, then (notwithstanding any
other provision of this Indenture or of the Securities) payment of interest or
principal (and premium, if any) 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 or at the Stated Maturity, provided that no interest
shall accrue for the period from and after such Interest Payment Date or Stated
Maturity, as the case may be.

                                  ARTICLE TWO

                                SECURITIES FORMS

       SECTION 201. Forms Generally.

       The Securities of each series and the Trustee's certificates of
authentication thereof shall be in substantially the forms set forth in this
Article, or in such other forms as shall be established by or pursuant to a
Board Resolution or in one or more indentures supplemental hereto, in each case
with such appropriate legends, 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 the rules of any
securities exchange or as may, consistently herewith, be determined by the
officers executing such Securities, as evidenced by their execution thereof. If
the form of Securities of any series is established by action taken pursuant to
a Board Resolution, a copy of an appropriate record of such action shall be
certified by the Secretary or an Assistant Secretary of the Company and
delivered to the Trustee at or prior to the delivery of the Company Order
contemplated by Section 303 for the authentication and delivery of such
Securities.

       The definitive Securities shall be printed, lithographed or engraved or
produced by any combination of these methods on steel engraved borders or may be
produced in any other manner, all as determined by the officers executing such
Securities, as evidenced by their execution of such Securities.

       SECTION 202. [Intentionally omitted]

       SECTION 203. [Intentionally omitted]

       SECTION 204. Additional Provisions Required in Global Security.

       Unless otherwise specified as contemplated by Section 301 for the
Securities evidenced thereby, every Global Security issued hereunder shall bear
a legend in substantially the following form:

                                       14
<PAGE>   23

       [If a Global Security, insert -- THIS SECURITY IS A GLOBAL SECURITY
WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN
THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE
EXCHANGED IN WHOLE OR IN PART FOR A SECURITY REGISTERED, AND NO TRANSFER OF THIS
SECURITY IN WHOLE OR IN PART MAY BE REGISTERED, IN THE NAME OF ANY PERSON OTHER
THAN SUCH DEPOSITARY OR A NOMINEE THEREOF, EXCEPT IN THE LIMITED CIRCUMSTANCES
DESCRIBED IN THE INDENTURE.]

       [If a Global Security to be held by The Depository Trust Company, insert
-- UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE ISSUER OR ITS
AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY SECURITY
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 A PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE
& CO., HAS AN INTEREST HEREIN.]

       SECTION 205. Form of Trustee's Certificate of Authentication.

       The Trustee's certificate of authorization shall be in substantially the
following form:

       This is one of the Securities of the series designated therein referred
to in the within-mentioned Indenture.

                            U.S. Trust Company, National Association,
                                  as Trustee

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

                                 ARTICLE THREE

                                 THE SECURITIES

       SECTION 301. Amount Unlimited; Issuable in Series.

       The aggregate principal amount of Securities which may be authenticated
and delivered under this Indenture is unlimited.

       The Securities may be issued in one or more series. There shall be
established in or pursuant to a Board Resolution and, subject to Section 303,
set forth, or determined in the manner provided, in an Officers' Certificate, or
established in one or more indentures supplemental hereto, prior to the issuance
of Securities of any series,

                                       15
<PAGE>   24

              (1) the title of the Securities of the series (which shall
       distinguish the Securities of the series from Securities of any other
       series);

              (2) any limit upon the aggregate principal amount of the
       Securities of the series which may be authenticated and delivered under
       this Indenture (except for Securities authenticated and delivered upon
       registration of transfer of, or in exchange for, or in lieu of, other
       Securities of the series pursuant to Section 304, 305, 306, 906 or 1107
       and except for any Securities which, pursuant to Section 303, are deemed
       never to have been authenticated and delivered hereunder);

              (3) the Person to whom any interest on a Security of the series
       shall be payable, if other than the Person in whose name that Security
       (or one or more Predecessor Securities) is registered at the close of
       business on the Regular Record Date for such interest;

              (4) the date or dates on which the principal of any Securities of
       the series is payable;

              (5) the rate or rates at which any Securities of the series shall
       bear interest, if any, the date or dates from which any such interest
       shall accrue, the Interest Payment Dates on which any such interest shall
       be payable and the Regular Record Date for any such interest payable on
       any Interest Payment Date;

              (6) the place or places where the principal of and any premium and
       interest on any Securities of the series shall be payable;

              (7) the period or periods within which, the price or prices at
       which and the terms and conditions upon which any Securities of the
       series may be redeemed, in whole or in part, at the option of the Company
       and, if other than by a Board Resolution, the manner in which any
       election by the Company to redeem the Securities shall be evidenced;

              (8) the obligation, if any, of the Company to redeem or purchase
       any Securities of the series pursuant to any sinking fund or analogous
       provisions or at the option of the Holder thereof and the period or
       periods within which, the price or prices at which and the terms and
       conditions upon which any Securities of the series shall be redeemed or
       purchased, in whole or in part, pursuant to such obligation;

              (9) if other than denominations of $1,000 and any integral
       multiple thereof, the denominations in which any Securities of the series
       shall be issuable;

              (10) if the amount of principal of or any premium or interest on
       any Securities of the series may be determined with reference to an index
       or pursuant to a formula, the manner in which such amounts shall be
       determined;

              (11) if other than the currency of the United States of America,
       the currency, currencies or currency units in which the principal of or
       any premium or interest on any Securities of the series shall be payable
       and the manner of determining the equivalent

                                       16
<PAGE>   25

       thereof in the currency of the United States of America for any purpose,
       including for purposes of the definition of "Outstanding" in Section 101;

              (12) if the principal of or any premium or interest on any
       Securities of the series is to be payable, at the election of the Company
       or the Holder thereof, in one or more currencies or currency units other
       than that or those in which such Securities are stated to be payable, the
       currency, currencies or currency units in which the principal of or any
       premium or interest on such Securities as to which such election is made
       shall be payable, the periods within which and the terms and conditions
       upon which such election is to be made and the amount so payable (or the
       manner in which such amount shall be determined);

              (13) if other than the entire principal amount thereof, the
       portion of the principal amount of any Securities of the series which
       shall be payable upon declaration of acceleration of the Maturity thereof
       pursuant to Section 502;

              (14) if the principal amount payable at the Stated Maturity of any
       Securities of the series will not be determinable as of any one or more
       dates prior to the Stated Maturity, the amount which shall be deemed to
       be the principal amount of such Securities as of any such date for any
       purpose thereunder or hereunder, including the principal amount thereof
       which shall be due and payable upon any Maturity other than the Stated
       Maturity or which shall be deemed to be Outstanding as of any date prior
       to the Stated Maturity (or, in any such case, the manner in which such
       amount deemed to be the principal amount shall be determined);

              (15) if applicable, that the Securities of the series, in whole or
       any specified part, shall be defeasible pursuant to Section 1102 or
       Section 1103 or both such Sections and, if other than by a Board
       Resolution, the manner in which any election by the Company to defease
       such Securities shall be evidenced;

              (16) if applicable, that any Securities of the series shall be
       issuable in whole or in part in the form of one or more Global Securities
       and, in such case, the respective Depositaries for such Global
       Securities, the form of any legend or legends which shall be borne by any
       such Global Security in addition to or in lieu of that set forth in
       Section 204 and any circumstances in addition to or in lieu of those set
       forth in Clause (2) of the last paragraph of Section 305 in which any
       such Global Security may be exchanged in whole or in part for Securities
       registered, and any transfer of such Global Security in whole or in part
       may be registered, in the name or names of Persons other than the
       Depositary for such Global Security or a nominee thereof;

              (17) any addition to or change in the Events of Default which
       applies to any Securities of the series and any change in the right of
       the Trustee or the requisite Holders of such Securities to declare the
       principal amount thereof due and payable pursuant to Section 502;

              (18) any addition to or change in the covenants set forth in
       Article Ten which applies to Securities of the series;

                                       17
<PAGE>   26

              (19) if the Securities of the series will be issued with original
       issue discount, the amount of original issue discount, the method by
       which the accreted value of the securities will be determined, the dates
       from and to which original issue discount will accrue and other terms
       relating to original issue discount; and

              (20) any other terms of the series (which terms shall not be
       inconsistent with the provisions of this Indenture, except as permitted
       by Section 901).

       All Securities of any one series shall be substantially identical except
as to denomination and except as may otherwise be provided in or pursuant to the
Board Resolution referred to above and (subject to Section 303) set forth, or
determined in the manner provided, in the Officers' Certificate referred to
above or in any such indenture supplemental hereto.

       If any of the terms of the series are established by action taken
pursuant to a Board Resolution, a copy of an appropriate record of such action
shall be certified by the Secretary or an Assistant Secretary of the Company and
delivered to the Trustee at or prior to the delivery of the Officers'
Certificate setting forth the terms of the series.

       The Securities shall be subordinated in right of payment to Senior
Indebtedness as provided in Article Fifteen. The Securities shall not be
superior in right of payment to, and shall rank pari passu with Securities
issued as contemplated by Section 301.

       SECTION 302. Denominations.

       The Securities of each series shall be issuable only in registered form
without coupons and only in denominations as shall be specified as contemplated
by Section 301. In the absence of any such specified denomination with respect
to the Securities of any series, the Securities of such series shall be issuable
in denominations of $1,000, and any integral multiple thereof.

       SECTION 303. Execution, Authentication, Delivery and Dating.

       The Securities shall be executed on behalf of the Company by its Chief
Executive Officer, its President, its Executive Vice President or one of its
Vice Presidents and attested by its Secretary or an Assistant Secretary. The
signature of any of these officers on the Securities may be manual or facsimile.

       Securities bearing the manual or facsimile signatures of individuals who
were at any time the proper officers of the Company shall bind the Company,
notwithstanding that such individuals or any of them have ceased to hold such
offices prior to the authentication and delivery of such Securities or did not
hold such offices at the date of such Securities.

       At any time and from time to time after the execution and delivery of
this Indenture, the Company may deliver Securities of any series executed by the
Company to the Trustee for authentication, together with a Company Order for the
authentication and delivery of such Securities; and the Trustee in accordance
with such Company Order shall authenticate and deliver such Securities.

       Each Security shall be dated the date of its authentication.

                                       18

<PAGE>   27

       No Security shall be entitled to any benefit under this Indenture or be
valid or obligatory for any purpose unless there appears on such Security a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by manual signature, and such certificate upon any
Security shall be conclusive evidence, and the only evidence, that such Security
has been duly authenticated and delivered hereunder. Notwithstanding the
foregoing, if any Security shall have been authenticated and delivered hereunder
but never issued and sold by the Company, and the Company shall deliver such
Security to the Trustee for cancellation as provided in Section 309, for all
purposes of this Indenture such Security shall be deemed never to have been
authenticated and delivered hereunder and shall never be entitled to the
benefits of this Indenture.

       SECTION 304. Temporary Securities.

       Pending the preparation of definitive Securities of any series, the
Company may execute, and upon a Company Order the Trustee shall authenticate and
deliver, temporary Securities which are printed, lithographed, typewritten,
mimeographed or otherwise produced, in any authorized denomination,
substantially of the tenor of the definitive Securities in lieu of which they
are issued and with such appropriate insertions, omissions, substitutions and
other variations as the officers executing such Securities may determine, as
evidenced by their execution of such Securities.

       If temporary Securities of any series are issued, the Company will cause
definitive Securities of that series to be prepared without unreasonable delay.
After the preparation of definitive Securities of that series, the temporary
Securities of that series shall be exchangeable for definitive Securities of
that series upon surrender of the temporary Securities of that series at any
office or agency of the Company designated pursuant to Section 1002, without
charge to the Holder. Upon surrender for cancellation of any one or more
temporary Securities of that series, the Company shall execute and the Trustee
shall authenticate and deliver in exchange therefor one or more definitive
Securities of the same series, of any authorized denominations and of like tenor
and aggregate principal amount. Until so exchanged, the temporary Securities
shall in all respects be entitled to the same benefits under this Indenture as
definitive Securities of such series and tenor.

       SECTION 305. Registration, Registration of Transfer and Exchange.

       (a) 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 1002 being herein sometimes
collectively referred to as the "Security Register") in which, subject to such
reasonable regulations as they may prescribe, the Company shall provide for the
registration of Securities and of transfers and exchanges of Securities. The
Trustee is hereby appointed "Security Registrar" for the purpose of registering
Securities and transfers and exchanges of Securities as herein provided.

       Subject to the other provisions of this Indenture regarding restrictions
on transfer, upon surrender for registration of transfer of any Security of a
series at an office or agency of the Company designated pursuant to Section 1002
for such purpose in accordance with the terms hereof, the Company shall execute,
and the Trustee shall authenticate and deliver, in the name of

                                       19
<PAGE>   28

the designated transferee or transferees, one or more new Securities of the same
series, of any authorized denominations and of a like tenor and aggregate
principal amount and bearing any applicable legends provided as contemplated by
this Indenture.

       At the option of the Holder and subject to the other provisions of this
Section 305, Securities of any series may be exchanged for other Securities of
the same series, of any authorized denominations and of a like tenor and
aggregate principal amount, upon surrender of the Securities to be exchanged at
such office or agency. Whenever any Securities are so surrendered for exchange,
the Company shall execute, and the Trustee shall authenticate and deliver, the
Securities which the Holder making the exchange is entitled to receive.

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

       Every Security presented or surrendered for registration of transfer or
for exchange shall (if so required by the Company or the Trustee) be duly
endorsed, or be accompanied by a written instrument of transfer in form
satisfactory to the Company and the Security Registrar duly executed, by the
Holder thereof or his attorney duly authorized in writing.

       No service charge shall be made to the Holder for any registration of
transfer or exchange of Securities, but the Company may require payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
connection with any registration of transfer or exchange of Securities, other
than exchanges pursuant to Section 304, 305, 906 or 1607 not involving any
transfer.

       If the Securities of any series (or of any series and specified tenor)
are to be redeemed in part, the Company shall not be required (A) to issue,
register the transfer of or exchange any Securities of that series (or of that
series and specified tenor, as the case may be) during a period beginning at the
opening of business 15 days before the day of the mailing of a notice of
redemption of any such Securities selected for redemption under Section 1603 and
ending at the close of business on the day of such mailing, or (B) to register
the transfer of or exchange any Security so selected for redemption in whole or
in part, except the unredeemed portion of any Security being redeemed in part.

       The provisions of Clauses (1), (2), (3) and (4) below shall apply only to
Global Securities:

              (1) Each Global Security authenticated under this Indenture shall
       be registered in the name of the Depositary designated for such Global
       Security or a nominee thereof and delivered to such Depositary or a
       nominee thereof or custodian therefor, and each such Global Security
       shall constitute a single Security for all purposes of this Indenture.

              (2) Notwithstanding any other provision of this Indenture or the
       Securities, exchanges of book-entry Securities for certificated
       Securities shall be made only in accordance with this Clause (2). A
       beneficial interest in a Global Security may not be exchanged for a
       Security in certificated form unless (i) DTC (x) notifies the Company
       that it is unwilling or unable to continue as Depositary for the Global
       Security or (y) has

                                       20
<PAGE>   29

       ceased to be a clearing agency registered under the Exchange Act and in
       either case the Company thereupon fails to appoint a successor
       Depositary, (ii) the Company, at its option, notifies the Trustee in
       writing that it elects to cause the issuance of the Securities in
       certificated form or (iii) there shall have occurred and be continuing an
       Event of Default or any event which after notice or lapse of time or both
       would be an Event of Default with respect to the Securities. In all
       cases, certificated Securities delivered in exchange for any Global
       Security or beneficial interests therein will be registered in the names,
       and issued in any approved denominations, requested by or on behalf of
       the Depositary (in accordance with its customary procedures). Any
       certificated Security issued in exchange for an interest in a Global
       Security will bear the legend restricting transfers, if any, that is
       borne by such Global Security. Any such exchange will be effected through
       the DWAC System and an appropriate adjustment will be made in the records
       of the Security Registrar to reflect a decrease in the principal amount
       of the relevant Global Security.

              (3) Subject to Clause (2) above, any exchange of a Global Security
       for other Securities may be made in whole or in part, and all Securities
       issued in exchange for a Global Security or any portion thereof shall be
       registered in such names as the Depositary for such Global Security shall
       direct.

              (4) Every Security authenticated and delivered upon registration
       of transfer of, or in exchange for or in lieu of, a Global Security or
       any portion thereof, whether pursuant to this Section, Section 304, 306,
       906 or 1107 or otherwise, shall be authenticated and delivered in the
       form of, and shall be, a Global Security, unless such Security is
       registered in the name of a Person other than the Depositary for such
       Global Security or a nominee thereof.

       SECTION 306. Mutilated, Destroyed, Lost and Stolen Securities.

       If any mutilated Security is surrendered to the Trustee, the Company
shall execute and the Trustee shall authenticate and deliver in exchange
therefor a new Security of the same series and of like tenor and principal
amount and bearing a number not contemporaneously outstanding.

       If there shall be delivered to the Company and the Trustee (i) evidence
to their satisfaction of the destruction, loss or theft of any Security and (ii)
such security or indemnity as may be required by them to save each of them and
any agent of either of them harmless, then, in the absence of notice to the
Company or the Trustee that such Security has been acquired by a bona fide
purchaser, the Company shall execute and the Trustee shall authenticate and
deliver, in lieu of any such destroyed, lost or stolen Security, a new Security
of the same series and of like tenor and principal amount and bearing a number
not contemporaneously outstanding.

       In case any such mutilated, destroyed, lost or stolen Security has become
or is about to become due and payable, the Company in the discretion of the
Company may, instead of issuing a new Security, pay such Security.

                                       21
<PAGE>   30

       Upon the issuance of any new Security under this Section, the Company may
require the payment of a sum sufficient to cover any tax or other governmental
charge that may be imposed in relation thereto and any other expenses (including
the fees and expenses of the Trustee) connected therewith.

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

       SECTION 307. Payment of Interest; Interest Rights Preserved.

       Except as otherwise provided as contemplated by Section 301 with respect
to any series of Securities, interest on any Security 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 Security (or one or more Predecessor
Securities) is registered at the close of business on the Regular Record Date
for such interest.

       Any interest on any Security of any series which is payable, but is not
punctually paid or duly provided for, on any Interest Payment Date (herein
called "Defaulted Interest") shall (a) bear interest at the rate per annum
stated in the form of Security provided as contemplated by Section 301 with
respect to any series of Securities (to the extent that the payment of such
interest shall be legally enforceable), and (b) forthwith cease to be payable to
the Holder on the relevant Regular Record Date by virtue of having been such
Holder, and such Defaulted Interest may be paid by the Company, at its election
in each case, as provided in Clause (1) or (2) below:

              (1) The Company may elect to make payment of any Defaulted
       Interest to the Persons in whose names the Securities of such series (or
       their respective Predecessor Securities) 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 Security of such series 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 in this
       Clause provided. 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 of such Special Record Date and, in the name and at the expense
       of the Company, shall cause notice of

                                       22
<PAGE>   31

       the proposed payment of such Defaulted Interest and the Special Record
       Date therefor to be mailed, first-class postage prepaid, to each Holder
       of Securities of such series at his address as it appears in the Security
       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 whose names the Securities of such series (or
       their respective Predecessor Securities) are registered at the close of
       business on such Special Record Date and shall no longer be payable
       pursuant to the following Clause (2).

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

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

       SECTION 308. Persons Deemed Owners.

       Prior to due presentment of a Security for registration of transfer, the
Company, the Trustee and any agent of the Company or the Trustee may treat the
Person in whose name such Security is registered as the owner of such Security
for the purpose of receiving payment of principal of and premium, if any, and
(subject to Section 307) interest on such Security and for all other purposes
whatsoever, whether or not such Security be overdue, and none of the Company,
the Trustee or any agent of the Company or the Trustee shall be affected by
notice to the contrary.

       SECTION 309. Cancellation.

       All Securities surrendered for payment, redemption, registration of
transfer, exchange, or for credit against any sinking fund payment shall, if
surrendered to any Person other than the Trustee, be delivered to the Trustee
and shall be promptly cancelled by it. The Company may at any time deliver to
the Trustee for cancellation any Securities previously authenticated and
delivered hereunder which the Company may have acquired in any manner
whatsoever, and all Securities so delivered shall be promptly cancelled by the
Trustee. No Securities shall be authenticated in lieu of or in exchange for any
Securities cancelled as provided in this Section, except as expressly permitted
by this Indenture. All cancelled Securities held by the Trustee shall be
disposed of in accordance with its standard procedures or as directed by a
Company Order.

                                       23
<PAGE>   32

       SECTION 310. Computation of Interest.

       Except as otherwise specified as contemplated by Section 301 for
Securities of any series, interest on the Securities of each series shall be
computed on the basis of a 360-day year of twelve 30-day months.

       SECTION 311. CUSIP Numbers.

       The Company shall in issuing the Securities of any series use CUSIP
numbers, and the Trustee shall use the applicable CUSIP number in notices of
redemption or exchange as a convenience to the Holders of the Securities of the
relevant series; provided, that any such notice may state that no
representation is made as to the accuracy or correctness of the CUSIP number or
numbers printed in the notice or on the certificates representing the
Securities of the relevant series and that reliance may be placed only on the
other identification numbers printed on the certificates representing the
Securities of such series.

                                  ARTICLE FOUR

                           SATISFACTION AND DISCHARGE

       SECTION 401. Satisfaction and Discharge of Indenture.

       This Indenture shall cease to be of further effect as to all Outstanding
Securities (except as to (i) rights of registration of transfer and exchange and
the Company's right of optional redemption, (ii) substitution of apparently
mutilated, defaced, destroyed, lost or stolen Securities, (iii) rights of
holders of Securities to receive payment of principal of and premium, if any,
and interest on the Securities, (iv) rights, obligations and immunities of the
Trustee under the Indenture and (v) rights of the holders of the Securities as
beneficiaries of the Indenture with respect to any property deposited with the
Trustee payable to all or any of them), and the Trustee, on demand of and at the
expense of the Company, shall execute proper instruments acknowledging
satisfaction and discharge of this Indenture, when

              (1) either

                     (A) the Company will have paid or caused to be paid the
              principal of, premium, if any, and interest on the Securities as
              and when the same will have become due and payable; or

                     (B) all Outstanding Securities (except lost, stolen or
              destroyed Securities which have been replaced or paid) have been
              delivered to the Trustee for cancellation;

       and the Company, in the case of (A) above, has deposited or caused to be
       deposited with the Trustee as trust funds in trust for the purpose an
       amount sufficient to pay and discharge the entire indebtedness on such
       Securities not theretofore delivered to the Trustee for cancellation, for
       principal of and premium, if any, and interest to the date of such
       deposit (in the case of Securities which have become due and payable) or
       to the Stated Maturity or Redemption Date, as the case may be;

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

              (3) the Company has delivered to the Trustee 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; and

                                       24
<PAGE>   33

              (4) the Trustee shall have received such other documents and
       assurances as the Trustee shall have reasonably requested.

Notwithstanding the satisfaction and discharge of this Indenture, (i) the
obligations of the Company to the Trustee under Section 607, (ii) rights of
substitution of apparently mutilated, defaced, destroyed, lost or stolen
Securities, (iii) rights of holders of Securities to receive payment of
principal of and premium, if any, and interest on the Securities, (iv) rights,
obligations and immunities of the Trustee under this Indenture (including, if
money shall have been deposited with the Trustee pursuant to subclause (B) of
Clause (1) of this Section, the obligations of the Trustee under Section 402 and
the last paragraph of Section 1003), and (v) rights of holders of the Securities
as beneficiaries of this Indenture with respect to any property deposited with
the Trustee payable to all or any of them, shall survive.

       SECTION 402. Application of Trust Money.

       Subject to the provisions of the last paragraph of Section 1003, all
money deposited with the Trustee pursuant to Section 401 shall be held in trust
and applied by it, in accordance with the provisions of the Securities 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 (and premium, if
any) and interest for whose payment such money has been deposited with the
Trustee.

                                  ARTICLE FIVE

                                    REMEDIES

       SECTION 501. Events of Default.

       "Event of Default", wherever used herein with respect to Securities of
any series, 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) or
caused by Article Fifteen:

              (1) default in the payment of the principal of any Security of
       that series when due, whether or not such payment is prohibited by the
       subordination provisions of this Indenture; or

              (2) continuance of the default in the payment of any interest upon
       any Security of that series for a period of 30 days after the date on
       which such interest becomes due and payable, whether or not such payment
       is prohibited by the subordination provisions of this Indenture; or

              (3) [intentionally deleted]

              (4) [intentionally deleted]

                                       25
<PAGE>   34

              (5) default in the performance, or breach, of any covenant or
       warranty of the Company in this Indenture (other than a covenant or
       warranty a default in whose performance or whose breach is elsewhere in
       this Section specifically dealt with or which has expressly been included
       in this Indenture solely for the benefit of series of Securities other
       than that series), and continuance of such default or breach for a period
       of 60 days after there has been given, by registered or certified mail,
       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
       Securities of that series a written notice specifying such default or
       breach and requiring it to be remedied and stating that such notice is a
       "Notice of Default" hereunder; or

              (6) a default or defaults under any bond(s), debenture(s), note(s)
       or other evidence(s) of Indebtedness by the Company or any Material
       Subsidiary of the Company or under any mortgage(s), indenture(s) or
       instrument(s) under which there may be issued or by which there may be
       secured or evidenced any Indebtedness of such type by the Company or any
       such Material Subsidiary with a principal amount then outstanding,
       individually or in the aggregate, in excess of an amount specified as
       contemplated by Section 301 for Securities of that series, whether such
       Indebtedness now exists or shall hereafter be created, which default or
       defaults shall constitute a failure to pay such Indebtedness when due at
       the final maturity thereof, or shall have resulted in such Indebtedness
       becoming or being declared due and payable prior to the date on which it
       would otherwise have become due and payable; or

              (7) a final judgment or final judgments (not subject to appeal)
       for the payment of money are entered against the Company or any Material
       Subsidiary in an aggregate amount specified as contemplated by Section
       301 for Securities of that series by a court or courts of competent
       jurisdiction, which judgments remain undischarged or unstayed for a
       period (during which execution shall not be effectively stayed) of 45
       days after the right to appeal all such judgments has expired; or

              (8) the entry by a court having jurisdiction in the premises of
       (A) a decree or order for relief in respect of the Company or any
       Material Subsidiary in an involuntary case or proceeding under any
       applicable Federal or State bankruptcy, insolvency, reorganization or
       other similar law or (B) a decree or order adjudging the Company or any
       Material Subsidiary a bankrupt or insolvent, or approving as properly
       filed a petition seeking reorganization, arrangement, adjustment or
       composition of or in respect of the Company or any Material Subsidiary
       under any applicable Federal or State law, or appointing a custodian,
       receiver, liquidator, assignee, trustee, sequestrator or other similar
       official of the Company or any Material Subsidiary or of any substantial
       part of its property, or ordering the winding up or liquidation of its
       affairs, and the continuance of any such decree or order for relief or
       any such other decree or order unstayed and in effect for a period of 60
       consecutive days; or

              (9) the commencement by the Company or any Material Subsidiary of
       a voluntary case or proceeding under any applicable Federal or State
       bankruptcy, insolvency, reorganization or other similar law or of any
       other case or proceeding to be adjudicated a bankrupt or insolvent, or
       the consent by it to the entry of a decree or order

                                       26
<PAGE>   35

       for relief in respect of the Company or any Material Subsidiary in an
       involuntary case or proceeding under any applicable Federal or State
       bankruptcy, insolvency, reorganization or other similar law or to the
       commencement of any bankruptcy or insolvency case or proceeding against
       it, or the filing by it of a petition or answer or consent seeking
       reorganization or relief under any applicable Federal or State law, or
       the consent by it to the filing of such petition or to the appointment of
       or taking possession by a custodian, receiver, liquidator, assignee,
       trustee, sequestrator or other similar official of the Company or any
       Material Subsidiary or of any substantial part of its property, or the
       making by it of an assignment for the benefit of creditors, or the
       admission by it in writing of its inability to pay its debts generally as
       they become due, or the taking of corporate action by the Company or any
       Material Subsidiary in furtherance of any such action; or

              (10) any other Event of Default provided as contemplated by
       Section 301 with respect to Securities of that series.

       SECTION 502. Acceleration of Maturity; Rescission and Annulment.

       Subject to Article Fifteen hereof, if an Event of Default (other than an
Event of Default specified in Section 501(8) or (9) with respect to the Company)
with respect to Securities of any series at the time Outstanding occurs and is
continuing, then and in every such case the Trustee or the Holders of not less
than 25% in aggregate principal amount of the Outstanding Securities of that
series may declare the principal of all the Securities of that series to be due
and payable immediately, by a notice in writing to the Company (and to the
Trustee if given by Holders), and upon any such declaration such principal and
any accrued interest, together with all other amounts due under this Indenture,
shall become immediately due and payable. If an Event of Default specified in
Section 501(8) or (9) with respect to Securities of any series at the time
Outstanding occurs, the principal of, any accrued interest on and other amounts
due under this Indenture with respect to the Securities of that series then
Outstanding, shall ipso facto become immediately due and payable without any
declaration or other Act on the part of the Trustee or any Holder; provided that
the provisions of Article Fifteen hereof shall have been complied with.

       At any time after such a declaration of acceleration with respect to
Securities of any series has been made and before a judgment or decree for
payment of the money due based on acceleration has been obtained by the Trustee
as hereinafter in this Article provided, the Holders of a majority in aggregate
principal amount of the Outstanding Securities of that series, by written notice
to the Company and the Trustee, may rescind and annul such declaration and its
consequences if:

              (1) the Company has paid or deposited with the Trustee a sum
       sufficient to pay

                     (A) all overdue interest on all Securities of that series,

                     (B) the principal of (and premium, if any, on) any
              Securities of that series which have become due otherwise than by
              such declaration of acceleration and interest thereon at the rate
              or rates prescribed therefor in such Securities,

                                       27
<PAGE>   36

                     (C) to the extent that payment of such interest is lawful,
              interest upon overdue interest at the rate or rates prescribed
              therefor in such Securities of that series, and

                     (D) all sums paid or advanced by the Trustee hereunder and
              the reasonable compensation, expenses, disbursements and advances
              of the Trustee, its agents and counsel;

       and

              (2) all Events of Default with respect to Securities of that
       series, other than the non-payment of the principal of Securities of that
       series which have become due solely by such declaration of acceleration,
       have been cured or waived as provided in Section 513.

No such rescission shall affect any subsequent default or impair any right
consequent thereon.

       SECTION 503. Collection of Indebtedness and Suits for Enforcement by
                    Trustee.

       The Company covenants that if

              (1) default is made in the payment of any interest on any Security
       of any series when such interest becomes due and payable and such default
       continues for a period of 30 days, or

              (2) default is made in the payment of the principal of (or
       premium, if any, on) any Security of any series at the Maturity thereof,

the Company will, upon demand of the Trustee, pay to it, for the benefit of the
Holders of Securities of such series, the whole amount then due and payable on
such Securities for principal (and premium, if any) and interest, and, to the
extent that payment of such interest shall be legally enforceable, interest on
any overdue principal (and premium, if any) and on any overdue interest, at the
rate or rates prescribed therefor in such Securities, and, in addition thereto,
such further amount as shall be sufficient to cover the costs and expenses of
collection incurred by the Trustee under this Indenture, 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 institute a
judicial proceeding for the collection of the sums so due and unpaid, may
prosecute such proceeding to judgment or final decree, and may enforce the same
against the Company or any other obligor upon the Securities of the relevant
series 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
such Securities, wherever situated.

       If an Event of Default with respect to Securities of any series occurs
and is continuing, the Trustee may in its discretion proceed to protect and
enforce its rights and the rights of the Holders of Securities of such series by
such appropriate judicial proceedings as the Trustee shall deem most effective
to protect and enforce any such rights, whether for the specific enforcement

                                       28
<PAGE>   37

of any covenant or agreement in this Indenture or in aid of the exercise of any
power granted herein, or to enforce any other proper remedy.

       SECTION 504. Trustee May File Proofs of Claim.

       In case of any judicial proceeding relative to the Company (or any other
obligor upon the Securities), its property or its creditors, the Trustee shall
be entitled and empowered, by intervention in such proceeding or otherwise, to
take any and all actions authorized under the Trust Indenture Act in order to
have claims of the Holders and the Trustee allowed in any such proceeding. In
particular, the Trustee shall be authorized to collect and receive any moneys,
securities or other property payable or deliverable upon the exchange of the
Securities or upon any such claims and, subject to the provisions of Article
Fifteen hereof, to distribute the same; and any custodian, receiver, assignee,
trustee, liquidator, sequestrator or other similar official 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 to 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 607.

       No provision of this Indenture 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
Securities 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; provided,
however, that the Trustee may, on behalf of the Holders, vote for the election
of a trustee in bankruptcy or similar official and be a member of a creditors or
other similar committee.

       SECTION 505. Trustee May Enforce Claims Without Possession of Securities.

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

       SECTION 506. Application of Money Collected.

       Subject to the provisions of Article Fifteen hereof, 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 (or premium, if any) or interest, upon
presentation of the Securities and the notation thereon of the payment if only
partially paid and upon surrender thereof if fully paid:

              FIRST: To the payment of all amounts due the Trustee under Section
       607; and

                                       29
<PAGE>   38

              SECOND: To the payment of the amounts then due and unpaid for
       principal of (and premium, if any) and interest on the Securities in
       respect of which or for the benefit of which such money has been
       collected, ratably, without preference or priority of any kind, according
       to the amounts due and payable on such Securities for principal (and
       premium, if any) and interest, respectively.

       The Trustee, upon prior written notice to the Company, may fix a record
date and payment date for any payment to the Holders of Securities of any series
pursuant to this Section 506.

       SECTION 507. Limitation on Suits.

       No Holder of any Security of any series 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

              (1) such Holder has previously given written notice to the Trustee
       of a continuing Event of Default with respect to Securities of that
       series;

              (2) the Holders of at least 25% in aggregate principal amount of
       the Outstanding Securities of that series 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;

              (3) such Holder or Holders have offered and, if requested,
       provided to the Trustee reasonable indemnity against the costs, expenses
       and liabilities to be incurred in compliance with such request;

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

              (5) 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 principal amount of the Outstanding Securities of that
       series;

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

       SECTION 508. Unconditional Right of Holders to Receive Principal, Premium
                    and Interest.

       Notwithstanding any other provision in this Indenture, the Holder of any
Security shall have the right, which is absolute and unconditional, to receive
payment of the principal of (and premium, if any) and (subject to Section 307)
interest on such Security on the respective Stated Maturities expressed in such
Security (or in the case of redemption, on the Redemption Date)

                                       30
<PAGE>   39

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 509. Restoration of Rights and Remedies.

       If the Trustee or any Holder has instituted any proceeding to enforce any
right or remedy under this Indenture 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, subject to any determination in
such proceeding, the Company, the Trustee and the Holders shall 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.

       SECTION 510. Rights and Remedies Cumulative.

       Except as otherwise provided with respect to the replacement or payment
of mutilated, destroyed, lost or stolen Securities in the last paragraph of
Section 306, 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 511. Delay or Omission Not Waiver.

       No delay or omission of the Trustee or of any Holder of any Securities 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 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 512. Control by Holders.

       By giving the Required Consent, those Persons giving the Required Consent
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, with respect to the Securities of relevant
series, provided that:

              (1) such direction shall not be in conflict with any rule of law
       or with this Indenture or expose the Trustee to personal liability (as
       determined in the sole discretion of the Trustee), and

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

                                       31
<PAGE>   40

       SECTION 513. Waiver of Past Defaults.

       By giving the Required Consent, those Persons giving the Required Consent
may, on behalf of the Holders of all Securities of the relevant series, waive
any past default hereunder with respect to such series and its consequences,
except a default:

              (1) in the payment of the principal of or interest on any Security
       of such series, or

              (2) 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 Security of such series affected.

       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 impair any right consequent thereon.

       SECTION 514. Undertaking for Costs.

       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 or omitted by
it as Trustee, a court may require any party litigant in such suit to file an
undertaking to pay the costs of such suit, and may assess costs against any such
party litigant, in the manner and to the extent provided in the Trust Indenture
Act; provided that neither this Section nor the Trust Indenture Act shall be
deemed to authorize any court to require such an undertaking or to make such an
assessment in any suit instituted by the Company.

       SECTION 515. Waiver of Stay or Extension 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 wherever enacted,
now or at any time hereafter in force, which may 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.

                                   ARTICLE SIX

                                   THE TRUSTEE

       SECTION 601. Certain Duties and Responsibilities.

       The duties and responsibilities of the Trustee shall be as provided by
the Trust Indenture Act. Notwithstanding the foregoing, 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

                                       32
<PAGE>   41

grounds for believing that repayment of such funds or adequate indemnity against
such risk or liability is not reasonably assured to it. 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.

       SECTION 602. Notice of Defaults.

       If a Default occurs hereunder with respect to Securities of any series,
the Trustee shall give the Holders of Securities of such series notice of such
Default as and to the extent provided by the Trust Indenture Act, unless such
Default has been cured or waived; provided, however, that in the case of any
Default of the character specified in Section 501(5) with respect to Securities
of such series, no such notice to Holders shall be given until at least 30 days
after the occurrence thereof.

       SECTION 603. Certain Rights of Trustee.

       Subject to the provisions of Section 601:

       (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 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 a Company Order and any
resolution of the Board of Directors may be sufficiently evidenced by a Board
Resolution;

       (c) whenever in the administration of this Indenture the Trustee shall
deem it desirable that a matter be proved or established prior to taking,
suffering or omitting any action hereunder, the Trustee may, in the absence of
bad faith on its part, rely upon an Officers' Certificate or an Opinion of
Counsel;

       (d) the Trustee may consult with counsel and the 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;

       (e) 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 it in compliance with such
request or direction reasonably satisfactory to the Trustee;

       (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, bond, debenture,
note, other evidence of indebtedness or other paper or document, but the
Trustee, in its discretion, may make such further inquiry or investigation into
such facts or matters as it may see fit, and, if the Trustee shall determine to
make such further

                                       33
<PAGE>   42

inquiry or investigation, it shall be entitled to examine the books, records and
premises of the Company, personally or by agent or attorney;

       (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; and

       (h) the Trustee shall not be liable for any action taken, suffered or
omitted by it in good faith which the Trustee reasonably believed to have been
authorized or within its rights or powers.

       SECTION 604. Not Responsible for Recitals or Issuance of Securities.

       The recitals contained herein and in the Securities of any series, except
the Trustee's certificates of authentication, shall be taken as the statements
of the Company, and the Trustee and any Authenticating Agent assumes no
responsibility for their correctness. The Trustee makes no representations as to
the validity or sufficiency of this Indenture or the Securities of any series.
The Trustee and any Authenticating Agent shall not be accountable for the use or
application by the Company of Securities of any series or the proceeds thereof.

       SECTION 605. May Hold Securities.

       The Trustee, any Authenticating Agent, any Paying Agent, any Security
Registrar (if other than the Trustee) or any other agent of the Company, in its
individual or any other capacity, may become the owner or pledgee of Securities
and, subject to Sections 608 and 613, may otherwise deal with the Company with
the same rights it would have if it were not Trustee, Authenticating Agent,
Paying Agent, Security Registrar or such other agent.

       SECTION 606. Money Held in Trust.

       Money held by the Trustee in trust hereunder need not be segregated from
other funds except to the extent required by law. The Trustee shall be under no
liability for interest on any money received by it hereunder except as otherwise
agreed with the Company.

       SECTION 607. Compensation and Reimbursement.

       The Company agrees:

              (1) to pay to the Trustee from time to time reasonable
       compensation for all services rendered by it hereunder (which
       compensation shall not be limited by any provision of law in regard to
       the compensation of a trustee of an express trust);

              (2) except as otherwise expressly provided herein, to reimburse
       the Trustee upon its request for all reasonable expenses, disbursements
       and advances incurred or made by the Trustee in accordance with any
       provision of this Indenture (including the reasonable compensation and
       the expenses and disbursements of its agents and counsel), except any

                                       34
<PAGE>   43

       such expense, disbursement or advance as may be attributable to its
       negligence or bad faith; and

              (3) to indemnify the Trustee for, and to hold it harmless against,
       any loss, liability or expense (including the reasonable compensation,
       expenses and disbursements of its agents, accountants, experts and
       counsel) incurred without negligence or bad faith on its part, arising
       out of or in connection with the acceptance or administration of this
       trust, including the costs and expenses of enforcing this Indenture
       against the Company (including, without limitation, this Section 607) and
       of defending itself against any claim (whether asserted by any Holder or
       the Company) or liability in connection with the exercise or performance
       of any of its powers or duties hereunder.

       The provisions of this Section 607 shall survive any termination of this
Indenture and the resignation or removal of the Trustee.

       As security for the performance of the obligations of the Company under
this Section 607, the Trustee shall have a lien prior to the Securities of every
series upon all property and funds held or collected by the Trustee, except
funds held in trust for the payment of principal of (and premium, if any) or
interest on particular series of Securities. The Trustee's right to receive
payment of any amounts due under this Section 607 shall not be subordinate to
any other liability or indebtedness of the Company (even though the Securities
may be so subordinated).

       When the Trustee incurs expenses or renders services after an Event of
Default specified in Section 501(8) or (9) occurs, the expenses and the
compensation for such services are intended to constitute expenses of
administration under Title 11, U.S. Code, or any similar Federal state or
foreign law for the relief of debtors.

       SECTION 608. Disqualification; Conflicting Interests.

       If the Trustee has or shall acquire a conflicting interest within the
meaning of the Trust Indenture Act, the Trustee shall either eliminate such
interest or resign, to the extent and in the manner provided by, and subject to
the provisions of, the Trust Indenture Act and this Indenture. To the extent
permitted by the Trust Indenture Act, the Trustee shall not be deemed to have a
conflicting interest by virtue of being a trustee under this Indenture with
respect to Securities of more than one series of a trustee under other
indentures relating to securities issued or to be issued by the Company.

       SECTION 609. Corporate Trustee Required; Eligibility.

       There shall at all times be a Trustee hereunder with respect to the
Securities of each series, which may be Trustee hereunder for Securities of one
or more other series. Each Trustee must be a Person that is eligible pursuant to
the Trust Indenture Act to act as such and has a combined capital and surplus of
at least $50,000,000 and has its Corporate Trust Office in the Borough of
Manhattan, The City of New York, New York. If any such Person publishes reports
of condition at least annually, pursuant to law or to the requirements of a
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 Person 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

                                       35
<PAGE>   44

the Trustee with respect to the Securities of any series shall cease to be
eligible in accordance with the provisions of this Section, it shall resign
immediately in the manner and with the effect hereinafter specified in this
Article.

       SECTION 610. Resignation and Removal; Appointment of Successor.

       (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 611, at which
time the retiring Trustee shall be fully discharged from its obligations
hereunder.

       (b) A Trustee may resign at any time with respect to the Securities of
one or more series by giving written notice thereof to the Company. If an
instrument of acceptance by a successor Trustee shall not have been delivered to
the Trustee within 30 days after the giving of such notice of resignation, the
resigning Trustee may petition any court of competent jurisdiction for the
appointment of a successor Trustee with respect to the Securities of such
series.

       (c) A Trustee may be removed at any time with respect to the Securities
of any series by Act of the Holders of a majority in principal amount of the
Outstanding Securities of such series, delivered to the Trustee and to the
Company.

       (d) If at any time:

              (1) the Trustee shall fail to comply with Section 608 after
       written request therefor by the Company or by any Holder who has been a
       bona fide Holder of a Security for at least six months, or

              (2) the Trustee shall cease to be eligible under Section 609 and
       shall fail to resign after written request therefor by the Company or by
       any such Holder, 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 of
       rehabilitation, conservation or liquidation,

then, in any such case, (i) the Company, by Board Resolution, may remove the
Trustee with respect to all Securities, or (ii) subject to Section 514, any
Holder who has been a bona fide Holder of a Security 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 with respect to all
Securities and the appointment of a successor Trustee or Trustees.

       (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, with
respect to the Securities of one or more series, the Company, by a Board
Resolution, shall promptly appoint a successor Trustee or Trustees with respect
to the Securities of that or those series (it being understood that any such
successor Trustee may be appointed with respect to the Securities of one or more
or all of such series and that at any time there shall be only one Trustee with
respect to the Securities of any particular series) and shall comply with the
applicable requirements of Section 611. If, within

                                       36
<PAGE>   45

one year after such resignation, removal or incapability, or the occurrence of
such vacancy, a successor Trustee with respect to the Securities of any series
shall be appointed by Act of the Holders of a majority in principal amount of
the Outstanding Securities of such series delivered to the Company and the
retiring Trustee, the successor Trustee so appointed shall, forthwith upon its
acceptance of such appointment in accordance with the applicable requirements of
Section 611, become the successor Trustee with respect to the Securities of such
series and to that extent supersede the successor Trustee appointed by the
Company. If no successor Trustee with respect to the Securities of any series
shall have been so appointed by the Company or the Holders and accepted
appointment in the manner required by Section 611, any Holder who has been a
bona fide Holder of a Security of such series 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 with respect
to the Securities of such series.

       (f) The Company shall give notice of each resignation and each removal of
the Trustee with respect to the Securities of any series and each appointment of
a successor Trustee with respect to the Securities of any series to all Holders
of Securities of such series in the manner provided in Section 106. Each notice
shall include the name of the successor Trustee with respect to the Securities
of such series and the address of its Corporate Trust Office.

       SECTION 611. Acceptance of Appointment by Successor.

       In case of the appointment hereunder of a successor Trustee with respect
to all Securities, every such successor Trustee so appointed 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; but, on request of the
Company or successor Trustee, such retiring Trustee shall, upon payment of its
charges execute and deliver an instrument transferring to such successor Trustee
all the rights, powers and trusts of the retiring Trustee and shall duly assign,
transfer and deliver to such successor Trustee all property and money held by
such retiring Trustee hereunder.

       In case of the appointment hereunder of a successor Trustee with respect
to the Securities of one or more (but not all) series, the Company, the retiring
Trustee and each successor Trustee with respect to the Securities of one or more
series shall execute and deliver an indenture supplemental hereto wherein each
successor Trustee shall accept such appointment and which (1) shall contain such
provisions as shall be necessary or desirable to transfer and confirm to, and to
vest in, each successor Trustee all the rights, powers, trusts and duties of the
retiring Trustee with respect to the Securities of that or those series to which
the appointment of such successor Trustee relates, (2) if the retiring Trustee
is not retiring with respect to all Securities, shall contain such provisions as
shall be deemed necessary or desirable to confirm that all the rights, powers,
trusts and duties of the retiring Trustee with respect to the Securities of that
or those series as to which the retiring Trustee is not retiring shall continue
to be vested in the retiring Trustee, and (3) shall add to or change any of the
provisions of this Indenture as shall be necessary to provide for or facilitate
the administration of the trusts hereunder by more than one

                                       37
<PAGE>   46

Trustee, it being understood that nothing herein or in such supplemental
indenture shall constitute such Trustees co-trustees of the same trust and that
each such Trustee shall be trustee of a trust or trusts hereunder separate and
apart from any trust or trusts hereunder administered by any other such Trustee;
and upon the execution and delivery of such supplemental indenture the
resignation or removal of the retiring Trustee shall become effective to the
extent provided therein and each 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 with respect to the Securities of that or
those series to which the appointment of such successor Trustee relates; but, on
request of the Company or any successor Trustee, such retiring Trustee shall
duly assign, transfer and deliver to such successor Trustee all property and
money held by such retiring Trustee hereunder with respect to the Securities of
that or those series to which the appointment of such successor Trustee relates.

       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, powers and trusts referred to in the
first or second preceding paragraph, as the case may be.

       No successor Trustee shall accept its appointment unless at the time of
such acceptance such successor Trustee shall be qualified and eligible under
this Article.

       SECTION 612. Merger, Conversion, Consolidation or Succession to Business.

       Any corporation into which the Trustee may be merged or converted or with
which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all the corporate trust business
of the Trustee, shall be the successor of the Trustee hereunder, provided that
such corporation shall be otherwise qualified and eligible under this Article,
without the execution or filing of any paper or any further act on the part of
any of the parties hereto. In case any Securities shall have been authenticated,
but not delivered, by the Trustee then in office, any successor by merger,
conversion or consolidation to such authenticating Trustee may adopt such
authentication and deliver the Securities so authenticated with the same effect
as if such successor Trustee had itself authenticated such Securities.

       SECTION 613. Preferential Collection of Claims Against the Company.

       If and when the Trustee shall be or become a creditor of the Company (or
any other obligor upon the Securities), the Trustee shall be subject to the
provisions of the Trust Indenture Act regarding the collection of claims against
the Company (or any such other obligor).

       SECTION 614. Appointment of Authenticating Agent.

       The Trustee may appoint an authenticating agent or agents (an
"Authenticating Agent") with respect to one or more series of Securities which
shall be authorized to act on behalf of the Trustee to authenticate Securities
of such series issued upon original issue and upon exchange, registration of
transfer or partial repurchase or redemption thereof or pursuant to Section 306,
and Securities so authenticated shall be entitled to the benefits of this
Indenture and shall be valid and obligatory for all purposes as if authenticated
by the Trustee hereunder. Wherever reference

                                       38
<PAGE>   47

is made in this Indenture to the authentication and delivery of Securities by
the Trustee or the Trustee's certificate of authentication, such reference shall
be deemed to include authentication and delivery on behalf of the Trustee by an
Authenticating Agent and a certificate of authentication executed on behalf of
the Trustee by an Authenticating Agent. Each Authenticating Agent shall be
acceptable to the Company and shall at all times be a corporation organized and
doing business under the laws of the United States of America, any State thereof
or the District of Columbia, authorized under such laws to act as Authenticating
Agent, having a combined capital and surplus of not less than $50,000,000 and
subject to supervision or examination by Federal or State authority. If such
Authenticating Agent publishes reports of condition at least annually, pursuant
to law or to the requirements of said supervising or examining authority, then
for the purposes of this Section, the combined capital and surplus of such
Authenticating Agent 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 an
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, such Authenticating Agent shall resign immediately
in the manner and with the effect specified in this Section.

       Any corporation into which an Authenticating Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, conversion or consolidation to which such Authenticating Agent
shall be a party, or any corporation succeeding to the corporate agency or
corporate trust business of an Authenticating Agent, shall continue to be an
Authenticating Agent, provided such corporation shall be otherwise eligible
under this Section, without the execution or filing of any paper or any further
act on the part of the Trustee or the Authenticating Agent.

       An Authenticating Agent may resign at any time by giving written notice
thereof to the Trustee and to the Company. The Trustee may at any time terminate
the agency of an Authenticating Agent by giving written notice thereof to such
Authenticating Agent and to the Company. Upon receiving such a notice of
resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent which shall be acceptable to the Company and shall give notice of such
appointment in the manner provided in Section 106 to all Holders of Securities
of the series with respect to which such Authenticating Agent will serve. Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, with like effect as if originally named as an Authenticating Agent.
No successor Authenticating Agent shall be appointed unless eligible under the
provisions of this Section.

       The Trustee agrees to pay to each Authenticating Agent from time to time
reasonable compensation for its services under this Section, and the Trustee
shall be entitled to be reimbursed for such payments, subject to the provisions
of Section 607.

       If an appointment with respect to one or more series is made pursuant to
this Section, the Securities of such series may have endorsed thereon, in lieu
of the Trustee's certificate of authentication, an alternative certificate of
authentication in the following form:

                                       39
<PAGE>   48
      This is one of the Securities of the series designated therein referred to
in the within-mentioned Indenture.

                                 U.S. Trust Company, National Association,
                                        As Trustee

                                 By:
                                        ----------------------------------------
                                        As Authenticating Agent

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

                                 ARTICLE SEVEN

              HOLDERS' LISTS AND REPORTS BY TRUSTEE AND THE COMPANY

      SECTION 701. Company to Furnish Trustee Names and Addresses of Holders.

      The Company will furnish or cause to be furnished to the Trustee

      (a) 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 of Securities of each Series as of such Regular Record
Date, and

      (b) at such other times as the Trustee may request in writing, within 30
days after the 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;

excluding from any such list names and addresses received by the Trustee in its
capacity as Security Registrar.

      SECTION 702. Preservation of Information; Communications to Holders.

      (a) The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in Section 701 and the names and
addresses of Holders received by the Trustee in its capacity as Security
Registrar. The Trustee may destroy any list furnished to it as provided in
Section 701 upon receipt of a new list so furnished.

      (b) The rights of Holders to communicate with other Holders with respect
to their rights under this Indenture or under the Securities, and the
corresponding rights and duties of the Trustee, shall be as provided by the
Trust Indenture Act.

                                       40
<PAGE>   49

      (c) Every Holder of Securities, by receiving and holding the same, agrees
with the Company and the Trustee that none of the Company, the Trustee or any
agent of any of them shall be held accountable by reason of any disclosure of
information as to names and addresses of Holders made pursuant to the Trust
Indenture Act.

      SECTION 703. Reports by Trustee.

      (a) The Trustee shall transmit to Holders such reports concerning the
Trustee and its actions under this Indenture as may be required pursuant to the
Trust Indenture Act at the times and in the manner provided pursuant thereto.

      (b) A copy of each such report shall, at the time of such transmission to
Holders, be filed by the Trustee with each stock exchange upon which any
Securities are listed, with the Commission and with the Company.  The Company
will notify the Trustee when any Securities are listed on any stock exchange.

      SECTION 704. Reports by Company.

      The Company shall file with the Trustee and the Commission, and transmit
to Holders, such information, documents and other reports, and such summaries
thereof, as may be required pursuant to the Trust Indenture Act at the times and
in the manner provided pursuant to such Act and in the manner set forth in
Section 1006; provided that any such information, documents or reports required
to be filed with the Commission pursuant to Section 13 or 15(d) of the Exchange
Act ("SEC Reports") shall be filed with the Trustee within 15 days after the
same is so required to be filed with the Commission. In the event the Company
shall cease to be required to file SEC Reports pursuant to the Exchange Act, the
Company will nonetheless continue to file such reports with the Commission
(unless the Commission will not accept such a filing) and the Trustee and to
furnish copies of such SEC Reports to the Holders of Securities at the time the
Company is required to file such reports with the Trustee and will make such
information available to investors who request it in writing.

                                 ARTICLE EIGHT

                           MERGER, CONSOLIDATION, ETC.

      SECTION 801. Mergers, Consolidations and Certain Sales of Assets.

      The Company may not, in a single transaction or a series of related
transactions, (i) consolidate with or merge into any other Person or permit any
other Person to consolidate with or merge into the Company (other than a
consolidation or merger into the Company of a wholly owned Subsidiary organized
under the laws of the United States of America, a state of the United States of
America or the District of Columbia), or (ii) directly or indirectly, transfer,
sell, lease or otherwise dispose of (other than (A) any transfer, sale, lease or
disposition from any Restricted Subsidiary to another Restricted Subsidiary, or
(B) a transfer of any ownership or membership interest in any Restricted
Subsidiary from the Company to any Restricted Subsidiary) all or
substantially all of its assets (determined on a consolidated basis for the
Company and its subsidiaries taken as a whole and provided that the creation of
a lien on or in

                                       41
<PAGE>   50

any of its assets shall not in and of itself constitute the transfer, sale,
lease or disposition of the assets subject to the lien), unless: (1) in a
transaction in which the Company does not survive or in which the Company sells,
leases or otherwise disposes of all or substantially all of its assets to any
other Person, the successor entity to the Company shall be a corporation,
limited liability company, partnership or trust organized under the laws of the
United States of America or any State thereof or the District of Columbia and
shall expressly assume, by a supplemental indenture executed and delivered to
the Trustee in form satisfactory to the Trustee, all of the Company's
obligations under this Indenture; (2) immediately after giving effect to such
transaction, no Default or Event of Default shall have occurred and be
continuing; and (3) the Company has delivered to the Trustee an Officers'
Certificate and an Opinion of Counsel, each in form and substance satisfactory
to the Trustee stating that such consolidation, merger, conveyance, transfer,
lease or acquisition and, if a supplemental indenture is required in connection
with such transaction, such supplemental indenture, complies with this Article
and that all conditions precedent herein provided for relating to such
transaction have been complied with.

      SECTION 802. Successor Substituted.

      Upon any consolidation of the Company with, or merger of the Company with
or into, any other Person or any conveyance, transfer or lease of the properties
and assets of the Company substantially as an entirety in accordance with
Section 801, the successor Person formed by such consolidation or into which the
Company is merged or to which such conveyance, transfer or lease is made shall
succeed to, and be substituted for, and may exercise every right and power of,
the Company under this Indenture with the same effect as if such successor
Person had been named as the Company herein, and thereafter, except in the case
of a lease, the predecessor Person shall be relieved of all obligations and
covenants under this Indenture and the Securities.

                                  ARTICLE NINE

                             SUPPLEMENTAL INDENTURES

      SECTION 901. Supplemental Indentures Without Consent of Holders.

      Without the consent of any Holders, the Company, when authorized by Board
Resolution, and the Trustee, at any time and from time to time, may enter into
one or more indentures supplemental hereto, in form satisfactory to the Trustee,
for any of the following purposes:

            (1) to cure any ambiguity, defect or inconsistency, to correct or
      supplement any provision in this Indenture that may be defective or
      inconsistent with any other provision in this Indenture;

            (2) to provide for or facilitate the issuance of Securities in
      bearer form registrable or not registrable and with or without interest
      coupons, or to provide for or facilitate the issuance of uncertificated
      Securities in addition to or in place of certificated Securities;

                                       42
<PAGE>   51

            (3) to evidence the succession of another Person to the Company and
      the assumption by any such successor of the covenants of the Company in
      this Indenture and in the Securities;

            (4) [intentionally deleted]

            (5) [intentionally deleted]

            (6) make any change (including, but not limited to, adding to the
      covenants of the Company or adding additional Events of Default) that
      would provide any additional rights or benefits to Holders of all or any
      series of Securities (and if such additional rights or benefits are to be
      for the benefit of less than all series of Securities, stating that such
      additional Events of Default are expressly being included solely for the
      benefit of such series) or that does not adversely affect the legal rights
      under the Indenture of any such Holder in any material respect, or to
      surrender any right or power herein conferred upon the Company;

            (7) comply with requirements of the Commission in order to maintain
      the qualification of the Indenture under the Trust Indenture Act of 1939,
      as amended;

            (8) to add to, change or eliminate any of the provisions of this
      Indenture in respect of one or more series of Securities, provided that
      any such addition, change or elimination (A) shall neither (i) apply to
      any Security of any series created prior to the execution of such
      supplemental indenture and entitled to the benefit of such provision nor
      (ii) modify the rights of the Holder of any such Security with respect to
      such provision or (B) shall become effective only when there is no such
      Security Outstanding;

            (9) to secure all or any series of Securities as provided as
      contemplated by Section 301 or otherwise;

            (10) to establish the form or terms of Securities of any series as
      permitted by Sections 201 or 301;

            (11) to evidence and provide for the acceptance of appointment
      hereunder by a successor Trustee with respect to the Securities of one or
      more series and to add to or change any of the provisions of this
      Indenture as may be necessary to provide for or facilitate the
      administration of the trusts hereunder by more than one Trustee, subject
      to the requirements of Section 611.

      SECTION 902. Supplemental Indentures with Consent of Holders.

      After receipt of the Required Consent, given by Act of those Persons
giving the Required Consent delivered to the Company and the Trustee, and
consistent with Section 513, the Company, when authorized by Board Resolution,
and the Trustee may enter into an indenture or indentures supplemental hereto
for the purpose of adding any provisions to or changing in any manner or
eliminating any of the provisions of this Indenture or of modifying in any
manner the rights of the Holders of Securities of such series under this
Indenture; provided, however, that no

                                       43
<PAGE>   52

such supplemental indenture shall, without the consent of the Holder of each
Outstanding Security affected thereby,

            (1) change the due date of the principal of, or any installment of
      interest on, any Security;

            (2) reduce the principal amount of, or interest on, Securities;

            (3) change the place or currency of payment of principal of, or
      interest on, any Security;

            (4) impair the right to institute suit for the enforcement of any
      payment on or with respect to any Security;

            (5) reduce the above stated percentage of outstanding Securities
      necessary to modify or amend the Indenture;

            (6) reduce the percentage of aggregate principal amount of
      outstanding Securities necessary for waiver of compliance with certain
      provisions of the Indenture or for waiver of certain defaults; or

            (7) modify any provisions of the Indenture relating to the
      modification and amendment of the Indenture or the waiver of past defaults
      or covenants, except as otherwise specified.

      A supplemental indenture which changes or eliminates any covenant or other
provision of this Indenture that has expressly been included solely for the
benefit of one or more particular series of Securities, or which modifies the
rights of the Holders of Securities of such series with respect to such covenant
or other provision, shall be deemed not to affect the rights under this
Indenture of the Holders of Securities of any other series.

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

      Notwithstanding anything to the contrary in this Section 902, no consent
of Holders of Securities shall be required for the Company to enter into a
supplemental indenture pursuant to Section 901.

      SECTION 903. Execution of Supplemental Indentures.

      In executing, or accepting the additional trusts created by, any
supplemental indenture permitted by this Article or the modifications thereby of
the trusts created by this Indenture, the Trustee shall be entitled to receive,
and (subject to Section 601) shall be fully protected in relying upon, an
Opinion of Counsel stating that the execution of such supplemental indenture is
authorized or permitted by this Indenture. The Trustee may, but shall not be
obligated to, enter into any such supplemental indenture which affects the
Trustee's own rights, duties or immunities under this Indenture or otherwise.

                                       44
<PAGE>   53

      SECTION 904. Effect of Supplemental Indentures.

      Upon the execution of any supplemental indenture under this Article, this
Indenture shall be modified in accordance therewith, and such supplemental
indenture shall form a part of this Indenture for all purposes; and every Holder
of Securities theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby.

      SECTION 905. Conformity with Trust Indenture Act.

      Every supplemental indenture executed pursuant to this Article shall
conform to the requirements of the Trust Indenture Act.

      SECTION 906. Reference in Securities to Supplemental Indentures.

      Securities of any series 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 Securities of any series so modified as to conform, in the
opinion of the Trustee and the Company, to any such supplemental indenture may
be prepared and executed by the Company and authenticated and delivered by the
Trustee in exchange for Outstanding Securities of such series.

                                  ARTICLE TEN

                                    COVENANTS

      SECTION 1001. Payment of Principal, Premium and Interest.

      The Company agrees for the benefit of each series of Securities that it
will duly and punctually pay the principal of and premium, if any, and interest,
on the Securities of that series in accordance with the terms of the Securities
and this Indenture.

      SECTION 1002. Maintenance of Office or Agency.

      The Company will maintain in the Borough of Manhattan, The City of New
York, New York, an office or agency where Securities of any series may be
presented or surrendered for payment, where Securities of that series may be
surrendered for registration of transfer or exchange and where notices and
demands to or upon the Company in respect of the Securities of that series and
this Indenture may be served. The Company will give prompt written notice to the
Trustee of the location, and any change in the location, of 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 the Borough of Manhattan, The City of New York, New
York) where the

                                       45
<PAGE>   54

Securities of one or more series may be presented or surrendered for any or all
such purposes and may from time to time rescind such designations; 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 Borough of
Manhattan, The City of New York, New York for such purposes. The Company will
give prompt written notice to the Trustee of any such designation or rescission
and of any change in the location of any such other office or agency.

      SECTION 1003. Money for Security Payments to be Held in Trust.

      If the Company shall at any time act as its own Paying Agent with respect
to any series of Securities, it will, on or before each due date of the
principal of (and premium, if any) or interest on any Securities of that series,
segregate and hold in trust for the benefit of the Persons entitled thereto a
sum sufficient to pay the principal (and 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 in writing of its
action or failure so to act. As provided in Section 504, upon any bankruptcy or
reorganization proceeding relative to the Company, the Trustee shall serve as
the Paying Agent for the Securities.

      Whenever the Company shall have one or more Paying Agents for any series
of Securities, it will, prior to each due date of the principal of (and premium,
if any) or interest on any Securities of that series, deposit with a Paying
Agent a sum sufficient to pay the principal (and premium, if any) or interest so
becoming due, such sum to be held in trust for the benefit of the Persons
entitled to such principal, premium or interest, and (unless such Paying Agent
is the Trustee) the Company will promptly notify the Trustee in writing of its
action or failure so to act. As provided in Section 504, upon any bankruptcy or
reorganization proceeding relative to the Company the Trustee shall serve as the
Paying Agent for the Securities.

      The Company will cause each Paying Agent for any series of Securities
other than the Trustee to execute and deliver to the Trustee an instrument in
which such Paying Agent shall agree with the Trustee, subject to the provisions
of this Section, that such Paying Agent will:

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

            (2) give the Trustee notice of any default by the Company (or any
      other obligor upon the Securities of that series) in the making of any
      payment in respect of the Securities of that series of principal (and
      premium, if any) or interest;

            (3) 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 for payment in respect of the
      Securities of that series; and

            (4) acknowledge, accept and agree to comply in all respects with the
      provisions of this Indenture relating to the duties, rights and
      obligations 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

                                       46
<PAGE>   55

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 shall 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 (and premium, if any)
or interest on any Security of any series and remaining unclaimed for two years
after such principal (and premium, if any) or interest has become due and
payable shall be paid to the Company on the Company Request, or (if then held by
the Company) shall be discharged from such trust; and the Holder of such
Security shall 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, shall 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, in a newspaper published in
the English language, customarily published on each Business Day and of general
circulation in the Borough of Manhattan, The City of New York, New York, 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 will be repaid to the Company.

      SECTION 1004. 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 its existence,
rights (charter and statutory) and franchises; provided, however, that the
Company shall not be required to preserve any such right or franchise if the
Board of Directors shall determine that the preservation thereof is no longer
desirable in the conduct of the business of the Company and that the loss
thereof is not disadvantageous in any material respect to the Holders.

      SECTION 1005. Maintenance of Properties.

      The Company will cause all properties used or useful in the conduct of its
business or the business of any Subsidiary, 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 1005 shall prevent the Company from discontinuing
operation or maintenance of any of such properties if such discontinuance is, as
determined in the good faith judgment of the Company, desirable in the conduct
of its business or, in the case of the Company, the business of any subsidiary,
and not disadvantageous in any material respect to the Holders of Securities.

                                       47
<PAGE>   56

      SECTION 1006. Provision of Financial Information.

      The Company has agreed to file with the Trustee, within 15 days after it
files them with the Commission, copies of the SEC Reports. In the event the
Company shall cease to be required to file SEC Reports pursuant to the Exchange
Act, the Company will nevertheless continue to file such reports with the
Commission (unless the Commission will not accept such a filing) and the
Trustee. The Company will furnish copies of the SEC Reports to the Holders of
Securities at the time the Company is required to file the same with the Trustee
and will make such information available to investors who request it in writing.

      SECTION 1007. [Intentionally deleted]

      SECTION 1008. Statement by Officers as to Default.

      (a) The Company will deliver to the Trustee within 120 days after the end
of each quarter of each fiscal year of the Company ending after the date hereof,
an Officers' Certificate, stating whether or not to the best knowledge of the
signers thereof the Company is in default in the performance and observance of
any of the terms, provisions and conditions of this Indenture and if the Company
shall be in default, specifying all such defaults and the nature and status
thereof of which they may have knowledge.

      (b) The Company shall deliver to the Trustee, as soon as possible and in
any event within 10 days after the Company becomes aware of the occurrence of a
Default or an Event of Default, an Officers' Certificate setting forth the
details of such Default or Event of Default and the action which the Company
proposes to take with respect thereto.

      SECTION 1009. Waiver of Certain Covenants and Obligations.

      Except as otherwise specified as contemplated by Section 301 for
Securities of any series, the Company may, with respect to the Securities of any
series, omit in any particular instance to comply with any covenant or condition
set forth in Sections 1004 through 1008, inclusive, if by giving the Required
Consent before or after the time for such compliance, those Persons giving the
Required Consent shall, by Act of such Persons, either waive such compliance in
such instance or generally waive compliance with such covenant or condition, but
no such waiver shall extend to or affect such covenant or condition except to
the extent so expressly waived, and, until such waiver shall become effective,
the obligations of the Company and the duties of the Trustee in respect of any
such covenant or condition shall remain in full force and effect.

                                 ARTICLE ELEVEN

                       DEFEASANCE AND COVENANT DEFEASANCE

      SECTION 1101. Company's Option to Effect Defeasance or Covenant
Defeasance.

      Except as otherwise specified as contemplated by Section 301 for such
Securities, the Company may, at its option by Board Resolution at any time
(subject to 10-day prior written notification to the Trustee), elect to have
either Section 1102 or Section 1103 applied to the

                                       48
<PAGE>   57

Outstanding Securities of any series upon compliance with the conditions set
forth below in this Article Eleven.

      SECTION 1102. Defeasance and Discharge.

      Upon the Company's exercise of the option provided in Section 1101
applicable to this Section, the Company shall be deemed to have been discharged
from its obligations with respect to the Outstanding Securities of the relevant
series 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
Outstanding Securities of the relevant series and to have satisfied all its
other obligations under such Securities and this Indenture insofar as such
Securities are concerned (and the Trustee, at the expense of the Company, 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 Outstanding Securities of the
            relevant series to receive, solely from the trust fund described in
            Section 1104 and as more fully set forth in such Section, payments
            in respect of the principal of (and premium, if any) and interest on
            such Securities of such series when such payments are due,

                  (B) the Company's obligations with respect to such Securities
            of such series under Sections 304, 305, 306, 1002 and 1003,

                  (C) the rights, powers, trusts, duties and immunities of the
            Trustee with respect to Securities of such series hereunder, and

                  (D) this Article Eleven.

      Subject to compliance with this Article Eleven, the Company may exercise
its option under this Section 1102 with respect to such Securities
notwithstanding the prior exercise of its option under Section 1103 with respect
to such Securities.

      SECTION 1103. Covenant Defeasance.

      Upon the Company's exercise of the option provided in Section 1101
applicable to this Section

                  (i) the Company shall be released from its obligations under
      Sections 1005 through 1008, inclusive, and 1201 with respect to the
      relevant series of Securities,

                  (ii) the occurrence of an event specified in Sections 501(5),
      and 501(6) shall not be deemed to be an Event of Default with respect to
      the relevant series of Securities, on and after the date the conditions
      set forth below are satisfied (hereinafter, "covenant defeasance"). For
      this purpose, such covenant defeasance means that 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

                                       49
<PAGE>   58

      in any other document, but the remainder of this Indenture and such
      Securities shall be unaffected thereby.

      SECTION 1104. Conditions to Defeasance or Covenant Defeasance.

      The following shall be the conditions to application of either Section
1102 or Section 1103 to such Outstanding Securities or any series of Securities,
as the case may be:

            (1) The Company shall irrevocably have deposited or caused to be
      deposited with the Trustee 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 series of
      Securities,

                  (A) money in an amount, or

                  (B) U.S. Government Obligations which through the scheduled
            payment of principal 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, sufficient, in the opinion of a
            nationally recognized firm of independent certified public
            accountants expressed in a written certification thereof delivered
            to the Trustee, to pay and discharge, and which shall be applied by
            the Trustee to pay and discharge, the principal of, premium, if any,
            and each installment of interest on the Securities of such series on
            the Stated Maturity of such principal or installment of interest on
            the day on which such payments are due and payable in accordance
            with the terms of this Indenture and of such Securities. For this
            purpose, "U.S. Government Obligations" means securities that are

                        (x) direct obligations of the United States of America
                  for the payment of which its full faith and credit is pledged
                  or

                        (y) obligations of a Person controlled or supervised by
                  and acting as an agency or instrumentality of the United
                  States of America the payment of which is unconditionally
                  guaranteed as a full faith and credit obligation by the United
                  States of America, which, in either case, are not callable or
                  redeemable at the option of the issuer thereof, and shall also
                  include a depositary receipt issued by a bank (as defined in
                  Section 3(a)(2) of the Securities Act) as custodian with
                  respect to any such U.S. Government Obligation or a specific
                  payment of principal of or interest on any such U.S.
                  Government Obligation held by such custodian for the account
                  of the holder of such depositary receipt, provided that
                  (except as required by law) -------- such custodian is not
                  authorized to make any deduction from the amount payable to
                  the holder of such depositary receipt from any amount received
                  by the custodian in respect of the U.S. Government Obligation
                  or the specific payment of principal of or interest on the
                  U.S. Government Obligation evidenced by such depositary
                  receipt.

                                       50
<PAGE>   59

            (2) No Default or Event of Default with respect to Securities of
      relevant series shall have occurred and be continuing on the date of such
      deposit and after giving effect thereto or, in connection with an election
      under Section 1102 insofar as Sections 501(8) and (9) are concerned, at
      any time during the period ending on the 91st 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) Such defeasance or covenant defeasance shall not cause the
      Trustee to have a conflicting interest as defined in Section 608 and for
      purposes of the Trust Indenture Act with respect to any securities of the
      Company.

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

            (5) The Company shall have delivered to the Trustee an Officers'
      Certificate and an Opinion of Counsel, each stating that all conditions
      precedent provided for relating to either the defeasance under Section
      1102 or the covenant defeasance under Section 1103 (as the case may be)
      have been complied with.

            (6) In the case of an election under Section 1102, 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 of this Indenture there has been a change
                  in the applicable Federal income tax law, in either case to
                  the effect that, and based thereon such opinion or the
                  Outstanding Securities of the relevant series, as the case may
                  be, shall confirm that, the Holders of the Outstanding
                  Securities will not recognize income, gain or loss for Federal
                  income tax purposes as a result of such deposit, defeasance
                  and discharge 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 deposit, defeasance and
                  discharge had not occurred.

            (7) In the case of an election under Section 1103, the Company shall
      have delivered to the Trustee an Opinion of Counsel to the effect that the
      Holders of the Securities of the relevant series will not recognize
      income, gain or loss for Federal income tax purposes as a result of such
      deposit and covenant 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 covenant defeasance had not occurred.

            (8) The Company shall have delivered to the Trustee an Opinion of
      Counsel to the effect that such deposit and defeasance or covenant
      defeasance shall not result in the trust arising from such deposit
      constituting an investment company as defined in the Investment Company
      Act of 1940, as amended, or such trust shall be qualified under such act
      or exempt from regulation thereunder.

                                       51
<PAGE>   60

      SECTION 1105. Deposited Money and U.S. Government Obligations to Be Held
                    in Trust; Other Miscellaneous Provisions.

      Subject to the provisions of the last paragraph of Section 1003, 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 1105, the "Trustee") pursuant to Section 1104 in respect of any series
of Securities shall be held in trust and applied by the Trustee, in accordance
with the provisions of such Securities 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 Holders of such
Securities of such series, of all sums due and to become due thereon in respect
of principal (and 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 against any tax, fee or
other charge imposed on or assessed against the U.S. Government Obligations
deposited pursuant to Section 1104 or the principal 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 Outstanding Securities of such series.

      Anything in this Article Eleven 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 1104 which, in the opinion of a nationally recognized accounting firm
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 1106. Reinstatement.

      If the Trustee or the Paying Agent is unable to apply any money in
accordance with Section 1102 or 1103 by reason of any order or judgment of any
court or governmental authority enjoining, restraining or otherwise prohibiting
such application, then the Company's obligations under this Indenture and the
Securities of the relevant series shall be revived and reinstated as though no
deposit had occurred pursuant to this Article Eleven until such time as the
Trustee or Paying Agent is permitted to apply all such money in accordance with
Section 1102 and 1103; provided, however, that if the Company makes any payment
of principal of (and premium, if any) any Security following the reinstatement
of its obligations, the Company shall be subrogated to the rights of the Holders
of such Securities of such series to receive such payment from the money held by
the Trustee or the Paying Agent.

      SECTION 1107. Repayment to Company.

      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 Securities and remaining unclaimed for two years after such
principal, and premium, if any, or interest has become due and payable shall be
paid to the Company on its written request or (if then held by the Company)
shall be discharged from such trust; and the Holder of such Securities shall
thereafter, as a creditor, look only to the Company for payment thereof, and all
liability of

                                       52
<PAGE>   61

the Trustee or such Paying Agent with respect to such trust money with respect
to such Securities, and all liability of the Company as trustee thereof with
respect to such Securities, shall 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, in the New York
Times and 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 notification or publication, any
unclaimed balance of such money then remaining will be repaid to the Company.

                                 ARTICLE TWELVE

                             [Intentionally deleted]

                                ARTICLE THIRTEEN

                             [Intentionally deleted]

                                ARTICLE FOURTEEN

                             [Intentionally deleted]

                                ARTICLE FIFTEEN

                           SUBORDINATION OF SECURITIES

      SECTION 1501. Securities Subordinated to Senior Indebtedness.

      The Company and each Holder, by its acceptance of Securities, agree that
(a) the payment of the principal of, or interest on, the Securities and (b) any
other payment in respect of the Securities, including on account of the
acquisition or purchase of the Securities by the Company are subordinated, to
the extent and in the manner provided in this Article Fifteen, to the prior
payment in full of all Senior Indebtedness of the Company, whether outstanding
at the date of this Indenture or thereafter created, incurred, assumed or
guaranteed, and that these subordination provisions are for the benefit of the
holders of Senior Indebtedness.

      This Article Fifteen shall constitute a continuing offer to all Persons
who, in reliance upon such provisions, become holders of, or continue to hold,
Senior Indebtedness, and such provisions are made for the benefit of the holders
of Senior Indebtedness, and such holders are made obligees hereunder and any one
or more of them may enforce such provisions.

      SECTION 1502. No Payment on Securities in Certain Circumstances.

      (a) No payment may be made by the Company on account of the principal of
or interest on the Securities, or to acquire any of the Securities for cash or
property, or on account of the

                                       53
<PAGE>   62

redemption provisions of the Securities, in the event of default in the payment
of any principal of, premium, if any, or interest on any Senior Indebtedness of
the Company when it becomes due and payable, whether at maturity or at a date
fixed for prepayment or by declaration or otherwise (a "Payment Default"),
unless and until such Payment Default has been cured or waived or otherwise has
ceased to exist.

      (b) Upon (i) the happening of an event of default (other than a Payment
Default) that permits, or would permit, with (w) the passage of time, (x) the
giving of notice, (y) the making of any payment in respect of the Securities
then required to be made, or (z) any combination thereof (collectively, a
"Non-Payment Default"), the holders of Designated Senior Indebtedness or their
representative immediately to accelerate the maturity of any Designated Senior
Indebtedness and (ii) written notice of such Non-Payment Default is given to the
Trustee by the holders of Designated Senior Indebtedness or their representative
or by the Company or its Representative (a "Payment Blockage Notice"), then,
unless and until such Non-Payment Default has been cured or waived or otherwise
has ceased to exist, no payment (by setoff or otherwise) may be made by or on
behalf of the Company on account of the principal of, or interest on, the
Securities, or to acquire or repurchase any of the Securities for cash or
property, or on account of the redemption provisions of the Securities, in any
such case other than payments made with Junior Securities.

      Notwithstanding the foregoing, unless (i) the Designated Senior
Indebtedness in respect of which such Non-Payment Default exists has been
declared due and payable in its entirety within 179 days after the Payment
Blockage Notice is delivered as set forth above (the "Payment Blockage Period"),
and (ii) such declaration has not been rescinded or waived, at the end of the
Payment Blockage Period, the Company shall be required to pay all sums not paid
to the Holders of the Securities during the Payment Blockage Period due to the
foregoing prohibitions and to resume all other payments as and when due on the
Securities. Not more than one Payment Blockage Notice may be given in any
365-day period, irrespective of the number of defaults with respect to
Designated Senior Indebtedness during such period. In no event, however, may the
total number of days during which any Payment Blockage Period or Payment
Blockage Periods are in effect exceed 179 days in the aggregate during any
consecutive 365-day period.

      (c) In furtherance of the provisions of Section 1501, in the event that,
notwithstanding the foregoing provisions of this Section 1502, any payment or
distribution of assets of the Company shall be received by the Trustee or the
Holders at a time when such payment or distribution is prohibited by the
provisions of this Section 1502, then such payment or distribution (subject to
the provisions of Section 1507) shall be received and held in trust by the
Trustee or such Holder for the benefit of the holders of Senior Indebtedness of
the Company, and shall be paid or delivered by the Trustee or such Holders, as
the case may be, to the holders of Senior Indebtedness of the Company remaining
unpaid or unprovided for or their representative or representatives, or to the
trustee or trustees under any indenture pursuant to which any instruments
evidencing any of such Senior Indebtedness of the Company may have been issued,
ratably according to the aggregate amounts remaining unpaid on account of the
Senior Indebtedness of the Company held or represented by each, for application
to the payment of all Senior Indebtedness of the Company remaining unpaid, to
the extent necessary to pay or provide for the payment of all such Senior
Indebtedness in full after giving effect to any concurrent payment or
distribution of, or provision therefor, to the holders of such Senior
Indebtedness.

                                       54

<PAGE>   63

      SECTION 1503. Securities Subordinated to Prior Payment of All Senior
                    Indebtedness on Dissolution, Liquidation or Reorganization.

      Upon any distribution of assets of the Company upon any dissolution,
winding up, total or partial liquidation or reorganization of the Company,
whether voluntary or involuntary, in bankruptcy, insolvency, receivership or a
similar proceeding or upon assignment for the benefit of creditors or any
marshalling of assets or liabilities:

      (a) the holders of all Senior Indebtedness of the Company shall first be
entitled to receive payments in full in cash or other payment satisfactory to
the holders of Senior Indebtedness (or have such payment duly provided for)
before the Holders are entitled to receive any payment on account of the
principal of, premium, if any, or interest, the Securities (other than payments
made in the form of Junior Securities);

      (b) any payment or distribution of assets of the Company of any kind or
character, whether in cash, property or securities (other than payments or
distributions in the form of Junior Securities) to which the Holders or the
Trustee on behalf of the Holders would be entitled (by setoff or otherwise),
except for the provisions of this Article Fifteen, shall be paid by the
liquidating trustee or agent or other Person making such a payment or
distribution directly to the holders of Senior Indebtedness of the Company or
their representative to the extent necessary to make payment in full in cash or
other payment satisfactory to the holders of Senior Debt of all such Senior
Indebtedness remaining unpaid, after giving effect to any concurrent payment or
distribution to the holders of such Senior Indebtedness; and

      (c) in the event that, notwithstanding the foregoing, any payment or
distribution of assets of the Company of any kind or character, whether in cash,
property or securities (other than payments or distributions in the form of
Junior Securities), shall be received by the Trustee or the Holders or any
Paying Agent (or, if the Company or an Affiliate of the Company is acting as its
own Paying Agent, money for any such payment or distribution shall be segregated
or held in trust) on account of the Securities before all Senior Indebtedness of
the Company is paid in full, such payment or distribution (subject to the
provisions of Section 1507) shall be received and held in trust by the Trustee
or such Holder or Paying Agent for the benefit of the holders of such Senior
Indebtedness, or their respective representative, ratably according to the
respective amounts of such Senior Indebtedness held or represented by each, to
the extent necessary to make payments as provided herein of all such Senior
Indebtedness remaining unpaid after giving effect to all concurrent payments and
distributions and all provisions therefor to or for the holders of such Senior
Indebtedness, but only to the extent that as to any holder of such Senior
Indebtedness, as promptly as practical following notice from the Trustee to the
holders of such Senior Indebtedness that such prohibited payment has been
received by the Trustee, Holder(s) or Paying Agent (or has been segregated as
provided above), such holder (or a representative therefor) notifies the Trustee
of the amounts then due and owing on such Senior Indebtedness, if any, held by
such holder and only the amounts specified in such notices to the Trustee shall
be paid to the holders of such Senior Indebtedness.

                                       55
<PAGE>   64

      SECTION 1504. Securityholders to Be Subrogated to Rights of Holders of
                    Senior Indebtedness.

      Subject to the payment in full of all Senior Indebtedness of the Company
as provided herein, the Holders of Securities shall be subrogated to the rights
of the holders of such Senior Indebtedness to receive payments or distributions
of assets of the Company applicable to the Senior Indebtedness until all amounts
owing on the Securities shall be paid in full, and for the purpose of such
subrogation no such payments or distributions to the holders of such Senior
Indebtedness by the Company, or by or on behalf of the Holders by virtue of this
Article Fifteen, which otherwise would have been made to the Holders shall, as
between the Company and the Holders, be deemed to be payment by the Company or
on account of such Senior Indebtedness, it being understood that the provisions
of this Article Fifteen are and are intended solely for the purpose of defining
the relative rights of the Holders, on the one hand, and the holders of such
Senior Indebtedness, on the other hand.

      If any payment or distribution to which the Holders would otherwise have
been entitled but for the provisions of this Article Fifteen shall have been
applied, pursuant to the provisions of this Article Fifteen, to the payment of
amounts payable under Senior Indebtedness of the Company, then the Holders shall
be entitled to receive from the holders of such Senior Indebtedness any payments
or distributions received by such holders of Senior Indebtedness in excess of
the amount sufficient to pay all amounts payable under or in respect of such
Senior Indebtedness in full.

      SECTION 1505. Obligations of the Company Unconditional.

      Nothing contained in this Article Fifteen or elsewhere in this Indenture
or in the Securities is intended to or shall impair as between the Company and
the Holders, the obligation of the Company, which is absolute and unconditional,
to pay to the Holders the principal and Redemption Price of, and interest on,
the Securities as and when the same shall become due and payable in accordance
with their terms, or is intended to or shall affect the relative rights of the
Holders and creditors of the Company other than the holders of the Senior
Indebtedness, nor shall anything herein or therein prevent the Trustee or any
Holder from exercising all remedies otherwise permitted by applicable law upon
default under this Indenture, subject to the rights, if any, under this Article
Fifteen, of the holders of Senior Indebtedness in respect of cash, property or
securities of the Company received upon the exercise of any such remedy.

      Notwithstanding anything to the contrary in this Article Fifteen or
elsewhere in this Indenture or in the Securities, upon any distribution of
assets of the Company referred to in this Article Fifteen, the Trustee, subject
to the provisions of Sections 601 and 603, and the Holders shall be entitled to
rely upon any order or decree made by any court of competent jurisdiction in
which such dissolution, winding up, liquidation or reorganization proceedings
are pending, or a certificate of the liquidating trustee or agent or other
Person making any distribution to the Trustee or to the Holders for the purpose
of ascertaining the Persons entitled to participate in such distribution, the
holders of the Senior Indebtedness and other Indebtedness of the Company, the
amount thereof or payable thereon, the amount or amounts paid or distributed
thereon and all other facts pertinent thereto or to this Article Fifteen so long
as such court has been apprised of

                                       56
<PAGE>   65

the provisions of, or the order, decree or certificate makes reference to, the
provisions of this Article Fifteen. Nothing in this Article Fifteen shall apply
to the claims of, or payments to, the Trustee under or pursuant to Sections 506
and 607.

      SECTION 1506. Trustee Entitled To Assume Payments Not Prohibited in
                    Absence of Notice.

      The Trustee or any Paying Agent shall not at any time be charged with
knowledge of the existence of any facts which would prohibit the making of any
payment to or by the Trustee or any Paying Agent unless and until a Trust
Officer of the Trustee or any Paying Agent shall have received, no later than
one Business Day prior to such payment, written notice thereof from the Company
or from one or more holders of Senior Indebtedness or from any representative
therefor and, prior to the receipt of any such written notice, the Trustee,
subject to the provisions of Sections 601 and 603, shall be entitled in all
respects conclusively to assume that no such fact exists.

      SECTION 1507. Application by Trustee of Assets Deposited with It.

      Amounts deposited in trust with the Trustee pursuant to and in accordance
with this Indenture shall be for the sole benefit of Holders of Securities and,
to the extent allocated for the payment of Securities, shall not be subject to
the subordination provisions of this Article Fifteen. Otherwise, any deposit of
assets with the Trustee or the Agent (whether or not in trust) for the payment
of any Securities shall be subject to the provisions of Sections 1501, 1502,
1503 and 1504; provided that, if prior to one Business Day preceding the date on
which by the terms of this Indenture any such assets may become distributable
for any purpose (including, without limitation, the payment of any amount due on
any Security) and the Trustee or such Paying Agent shall not have received with
respect to such assets the written notice provided for in Section 1506, then the
Trustee or such Paying Agent shall have full power and authority to receive such
assets and to apply the same to the purpose for which they were received, and
shall not be affected by any notice to the contrary which may be received by it
on or after such date.

      SECTION 1508. Subordination Rights Not Impaired by Acts or Omissions of
                    the Company or Holders of Senior Indebtedness.

      No right of any present or future holders of any Senior Indebtedness to
enforce subordination provisions contained in this Article Fifteen shall at any
time in any way be prejudiced or impaired by any act or failure to act on the
part of the Company or by any act or failure to act, in good faith, by any such
holder, or by any noncompliance by the Company with the terms of this Indenture,
regardless of any knowledge thereof which any such holder may have or be
otherwise charged with. The holders of Senior Indebtedness may extend, renew,
modify or amend the terms of the Senior Indebtedness or any security therefor
and release, sell or exchange such security and otherwise deal freely with the
Company, all without affecting the liabilities and obligations of the parties to
this Indenture or the Holders.

                                       57
<PAGE>   66

      SECTION 1509. Securityholders Authorize Trustee to Effectuate
                    Subordination of Securities.

      Each Holder of the Securities by his acceptance thereof authorizes and
expressly directs the Trustee on his behalf to take such action as may be
necessary or appropriate to effectuate the subordination provisions contained in
this Article Fifteen and to protect the rights of the Holders pursuant to this
Indenture, and appoints the Trustee his attorney-in-fact for such purpose,
including, in the event of any dissolution, winding up, liquidation or
reorganization of the Company (whether in bankruptcy, insolvency or receivership
proceedings or upon an assignment for the benefit of creditors of the Company),
the immediate filing of a claim for the unpaid balance of his Securities in the
form required in said proceedings and cause said claim to be approved. If the
Trustee does not file a proper claim or proof of debt in the form required in
such proceeding prior to 30 days before the expiration of the time to file such
claim or claims, then the holders of the Senior Indebtedness or their
representative are or is hereby authorized to have the right to file and are or
is hereby authorized to file an appropriate claim for and on behalf of the
Holders of said Securities. Nothing herein contained shall be deemed to
authorize the Trustee or the holders of Senior Indebtedness or their
representative to authorize or consent to or accept or adopt on behalf of any
Securityholder any plan of reorganization, arrangement, adjustment or
composition affecting the Securities or the rights of any Holder thereof, or to
authorize the Trustee or the holders of Senior Indebtedness or their
representative to vote in respect of the claim of any Securityholder in any such
proceeding.

      SECTION 1510. Right of Trustee to Hold Senior Indebtedness.

      The Trustee shall be entitled to all of the rights set forth in this
Article Fifteen in respect of any Senior Indebtedness at any time held by it to
the same extent as any other holder of Senior Indebtedness, and nothing in this
Indenture shall be construed to deprive the Trustee of any of its rights as such
holder.

      SECTION 1511. Article Fifteen Not to Prevent Events of Default.

      The failure to make any payment due on the Securities by reason of any
provision of this Article Fifteen shall not be construed as preventing the
occurrence of a Default or an Event of Default under Section 501 or in any way
prevent the Holders from exercising any right hereunder other than the right to
receive payment on the Securities.

      SECTION 1512. No Fiduciary Duty of Trustee to Holders of Senior
                    Indebtedness.

      The Trustee shall not be deemed to owe any fiduciary duty to the holders
of Senior Indebtedness, and shall not be liable to any such holders (other than
for its willful misconduct or negligence) if it shall in good faith mistakenly
pay over or distribute to the Holders of Securities or the Company or any other
Person, cash, property or securities to which any holders of Senior Indebtedness
shall be entitled by virtue of this Article Fifteen or otherwise. With respect
to the holders of Senior Indebtedness, the Trustee undertakes to perform or
observe only such of its covenants or obligations as are specifically set forth
in this Article and no implied covenants or obligations with respect to the
holders of Senior Indebtedness shall be read into this Indenture against the
Trustee. Nothing in this Section 1512 shall affect the obligation of any other
such Person to

                                       58
<PAGE>   67

hold such payment for the benefit of, and to pay such payment over to, the
holders of Senior Indebtedness or their representative.

                                ARTICLE SIXTEEN

                            REDEMPTION OF SECURITIES

      SECTION 1601. Applicability of Article.

      Securities of any series which are redeemable before their Stated Maturity
shall be redeemable in accordance with their terms and (except as otherwise
specified as contemplated by Section 301 for such Securities) in accordance with
this Article.

      SECTION 1602. Election to Redeem; Notice to Trustee.

      The election of the Company to redeem any Securities of any series shall
be evidenced by a Board Resolution or in another manner specified as
contemplated by Section 301 for such Securities. In case of any redemption at
the election of the Company of less than all the Securities of any series
(including any such redemption affecting only a single Security), the Company
shall, at least 60 days prior to the Redemption Date fixed by the Company
(unless a shorter notice shall be satisfactory to the Trustee), notify the
Trustee of such Redemption Date, of the principal amount of Securities of such
series to be redeemed and, if applicable, of the tenor of the Securities to be
redeemed. In the case of any redemption of Securities prior to the expiration of
any restriction on such redemption provided in the terms of such Securities or
elsewhere in this Indenture, the Company shall furnish the Trustee with an
Officers' Certificate evidencing compliance with such restriction.

      SECTION 1603. Selection by Trustee of Securities to Be Redeemed.

      If less than all the Securities of any series are to be redeemed (unless
all the Securities of such series and of a specified tenor are to be redeemed or
unless such redemption affects only a single Security), the particular
Securities to be redeemed shall be selected not more than 60 days prior to the
Redemption Date by the Trustee, from the Outstanding Securities of such series
not previously called for redemption, by such method as the Trustee shall deem
fair and appropriate and which may provide for the selection for redemption of a
portion of the principal amount of any Security of such series, provided that
the unredeemed portion of the principal amount of any Security of such series
shall be in an authorized denomination (which shall not be less than the minimum
authorized denomination) for such Security. If less than all the Securities of
such series and of a specified tenor are to be redeemed (unless such redemption
affects only a single Security), the particular Securities to be redeemed shall
be selected not more than 60 days prior to the Redemption Date by the Trustee,
from the Outstanding Securities of such series and specified tenor not
previously called for redemption in accordance with the preceding sentence.

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

                                       59
<PAGE>   68

      The provisions of the two preceding paragraphs shall not apply with
respect to any redemption affecting only a single Security, whether such
Security is to be redeemed in whole or in part. In the case of any such
redemption in part, the unredeemed portion of the principal amount of the
Security shall be in an authorized denomination (which shall not be less than
the minimum authorized denomination) for such Security.

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

      SECTION 1604. 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 Securities to be redeemed, at his address appearing in the
Security Register.

      All notices of redemption shall state:

            (1) the Redemption Date,

            (2) the Redemption Price,

            (3) if less than all the Outstanding Securities of any series
      consisting of more than a single Security are to be redeemed, the
      identification (and, in the case of partial redemption of any such
      Securities, the principal amounts) of the particular Securities to be
      redeemed and, if less than all the Outstanding Securities of any series
      consisting of a single Security are to be redeemed, the principal amount
      of the particular Security to be redeemed,

            (4) that on the Redemption Date the Redemption Price will become due
      and payable upon each such Security to be redeemed and, if applicable,
      that interest thereon will cease to accrue on and after said date,

            (5) the place or places where each such Security is to be
      surrendered for payment of the Redemption Price, and

            (6) that the redemption is for a sinking fund, if such is the case.

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

      SECTION 1605. Deposit of Redemption Price.

      Prior to any Redemption Date, the Company shall deposit with the Trustee
or with a Paying Agent (or, if the Company is acting as its own Paying Agent,
segregate and hold in trust as provided in Section 1003) an amount of money
sufficient to pay the Redemption Price of, and

                                       60
<PAGE>   69

(except if the Redemption Date shall be an Interest Payment Date) accrued
interest on, all the Securities which are to be redeemed on that date.

      SECTION 1606. Securities Payable on Redemption Date.

      Notice of redemption having been given as aforesaid, the Securities so to
be redeemed shall, on the Redemption Date, become due and payable at the
Redemption Price therein specified, and from and after such date (unless the
Company shall default in the payment of the Redemption Price and accrued
interest) such Securities shall cease to bear interest. Upon surrender of any
such Security for redemption in accordance with said notice, such Security shall
be paid by the Company at the Redemption Price, together with accrued interest
to the Redemption Date; provided, however, that, unless otherwise specified as
contemplated by Section 301, installments of interest whose Stated Maturity is
on or prior to the Redemption Date will be payable to the Holders of such
Securities, or one or more Predecessor Securities, registered as such at the
close of business on the relevant Record Dates according to their terms and the
provisions of Section 307.

      If any Security called for redemption shall not be so paid upon surrender
thereof for redemption, the principal and any premium shall, until paid, bear
interest from the Redemption Date at the rate prescribed therefor in the
Security.

      SECTION 1607. Securities Redeemed in Part.

      Any Security which is to be redeemed only in part shall be surrendered at
an office or agency of the Company designated for that purpose pursuant to
Section 1002 (with, if the Company or the Trustee so requires, due endorsement
by, or a written instrument of transfer in form satisfactory to the Company and
the Trustee duly executed by, the Holder thereof or his attorney duly authorized
in writing), and the Company shall execute, and the Trustee shall authenticate
and deliver to the Holder of such Security without service charge, a new
Security or Securities of the same series and of like tenor, 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 Security so
surrendered.

                                    * * * * *

      This Indenture may be executed in any number of counterparts, each of
which so executed shall be deemed to be an original, but all such counterparts
shall together constitute but one and the same Indenture.

                                       61
<PAGE>   70

      IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed.

                                    XO COMMUNICATIONS, INC.

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

                                    U.S TRUST COMPANY, NATIONAL
                                         ASSOCIATION, as Trustee

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

<PAGE>   71

STATE OF                  )
                          ) ss:
COUNTY OF [     ]         )

      On the ____ day of _________, ____, before me personally came
_________________________, to me known, who, being by me duly sworn, did depose
and say that he resides at ___________________, ________________________, that
he is ________________________ of XO Communications, Inc., one of the
corporations described in and which executed the foregoing instrument, and that
he signed his name thereto by like authority.

[Notarial Seal]

                                           -------------------------------------
                                           Notary Public

                                           COMMISSION EXPIRES

<PAGE>   72
STATE OF NEW YORK     )
                      )ss:
COUNTY OF NEW YORK    )

    On the _____ day of _______, _____, before me personally came
________________________, to me known, who, being by me duly sworn, did depose
and say that [s]he resides at ____________________, ______________________, that
[s]he is a ____________________ of U.S. Trust Company, National Association, one
of the corporations described in and which executed the foregoing instrument,
and that [s]he signed his or her name thereto by like authority.

[Notarial Seal]

                                       -----------------------------------------
                                       Notary Public

                                       COMMISSION EXPIRES<PAGE>   1

                                                                     Exhibit 4.3

                                WARRANT AGREEMENT

                         dated as of [________ __, ____]

                                     between

                             XO COMMUNICATIONS, INC.

                                       and

                    [NAME OF WARRANT AGENT], as Warrant Agent

                              Warrants to Purchase
                          [TITLE OF WARRANT SECURITIES]

<PAGE>   2

                                TABLE OF CONTENTS

<TABLE>
<S>                                                                                                                        <C>
ARTICLE I       ISSUANCE OF WARRANTS AND FORM, EXECUTION, DELIVERY AND REGISTRATION OF WARRANT CERTIFICATES..................1

        Section 1.1     Issuance of Warrants.................................................................................2

        Section 1.2     Form, Execution and Delivery of Warrant Certificates.................................................2

        Section 1.3     Transfer of Warrants.................................................................................3

        Section 1.4     Lost, Stolen, Mutilated or Destroyed Warrant Certificates............................................5

        Section 1.5     Cancellation of Warrant Certificates.................................................................5

        Section 1.6     Treatment of Holders.................................................................................6

ARTICLE II      EXERCISE PRICE, DURATION AND EXERCISE OF WARRANTS............................................................6

        Section 2.1     Exercise Price.......................................................................................6

        Section 2.2     Duration of Warrants.................................................................................6

        Section 2.3     Exercise of Warrants.................................................................................7

        Section 2.4     Cancellation.........................................................................................9

ARTICLE III     OTHER PROVISIONS RELATING TO RIGHTS OF HOLDERS...............................................................9

ARTICLE III [If Warrants are to be issued in Book-Entry Form: AND BENEFICIAL OWNERS] OF WARRANTS.............................9

        Section 3.1     No Rights as Holders of Warrant Securities Conferred by Warrants or Warrant Certificates.............9

        Section 3.2     Holder [If Warrants are to be issued in Book-Entry form: and Beneficial Owner] of Warrant
                        May Enforce Rights..................................................................................10

ARTICLE IV      CONCERNING THE WARRANT AGENT................................................................................10

        Section 4.1     Warrant Agent.......................................................................................10

        Section 4.2     Limitations on Warrant Agent's Obligations..........................................................10

        Section 4.3     Compliance With Applicable Laws.....................................................................12

        Section 4.4     Resignation and Appointment of Successor............................................................12

ARTICLE V       MISCELLANEOUS...............................................................................................13

        Section 5.1     Amendments..........................................................................................13

        Section 5.2     Merger, Consolidation, Sale, Transfer or Conveyance.................................................14

        Section 5.3     Notices and Demands to the Company and Warrant Agent................................................15

        Section 5.4     Addresses...........................................................................................15

        Section 5.5     Governing Law.......................................................................................15
</TABLE>

                                       -i-
<PAGE>   3

                                TABLE OF CONTENTS
                                  (continued)

<TABLE>
<CAPTION>
                                                                                                                          PAGE
        <S>             <C>                                                                                                <C>
        Section 5.6     Delivery of Prospectus..............................................................................15

        Section 5.7     Obtaining of Governmental Approvals.................................................................15

        Section 5.8     Payment of Taxes....................................................................................15

        Section 5.9     Benefits of Warrant Agreement.......................................................................16

        Section 5.10    Headings............................................................................................16

        Section 5.11    Severability........................................................................................16

        Section 5.12    Counterparts........................................................................................16

        Section 5.13    Inspection of Agreement.............................................................................16
</TABLE>

                                      -ii-
<PAGE>   4

                                WARRANT AGREEMENT

                WARRANT AGREEMENT, dated as of [________ __, ____] (as modified,
amended or supplemented, this "Agreement"), between XO COMMUNICATIONS, INC., a
Delaware corporation (the "Company") and [NAME OF WARRANT AGENT], a
[____________], as Warrant Agent (the "Warrant Agent").

                              W I T N E S S E T H:

                [If offer consists of Debt Securities with Warrants AND/OR
Warrants to Purchase Debt Securities: WHEREAS, the Company has entered into an
Indenture (the "[Senior] [Subordinated] Indenture"), dated as of [____________],
between the Company and [NAME OF TRUSTEE] as trustee (the "[Senior]
[Subordinated] Trustee"), providing for the issuance from time to time of its
unsecured [senior] [subordinated] [convertible] debentures, notes or other
evidences of indebtedness (the "[Senior] [Subordinated] Debt Securities"), to be
issued in one or more series as provided in the [Senior] [Subordinated]
Indenture [if Warrant Securities are not under same Indenture as Debt Securities
to which they are attached; and an Indenture (the "[Senior] [Subordinated]
Indenture," the Senior and Subordinated Indentures being referred to
collectively as the "Indentures") dated as of _______________ between the
Company and ______________, as trustee (the "[Senior] [Subordinated] Trustee,"
(the Senior and Subordinated Trustees being referred to collectively, as the
"Trustees"), providing for the issuance from time to time of its [senior]
[subordinated] debentures, notes or other evidences of indebtedness (the
"[Senior] [Subordinated] Debt Securities," the Senior and Subordinated Debt
Securities being referred to collectively as the "Debt Securities"), to be
issued in one or more series as provided in the [Senior] [Subordinated]
Indenture]; and]

                [If Securities and Warrants are to be offered together: WHEREAS,
the Company proposes to sell [title of Securities being offered] (the "Offered
Securities") together with warrants (each, a "Warrant") representing the right
to purchase [title of Securities purchasable upon exercise of Warrants] [If
Warrants for Depositary Shares are to be offered: , each representing a [1/__th]
interest in a share of [title of securities represented by Depositary Shares]]
(the "Warrant Securities" [If Warrants for Depositary Shares are to be offered:
, which term shall also refer, as appropriate, to such [title of securities
represented by Depositary Shares]), such warrant certificates and other warrant
certificates issued pursuant to this Agreement being herein called the "Warrant
Certificates"; and]

                [If offer consists of Warrants alone: WHEREAS, the Company
proposes to sell warrant certificates evidencing one or more warrants (each, a
"Warrant") representing the right to purchase [title of Securities purchasable
upon exercise of Warrants] [If Warrants for Depositary Shares are to be offered:
, each representing a [1/__th] interest in a share of [title of securities
represented by the Depositary Shares]] (the "Warrant Securities" [If Warrants
for Depositary Shares are to be offered: , which term shall also refer, as
appropriate, to such [title of securities represented by the Depositary
Shares]), such warrant certificates and other warrant certificates issued
pursuant to this Agreement being herein called the "Warrant Certificates"; and]

                WHEREAS, the Company desires the Warrant Agent to act on behalf
of the Company, and the Warrant Agent is willing so to act, in connection with
the issuance, transfer, exchange, exercise and cancellation of the Warrants, and
the Company wishes to set forth in this Agreement, among other things, the
provisions of the Warrants, the form of the Warrant

                                       1
<PAGE>   5

Certificates evidencing the Warrants and the terms and conditions upon which the
Warrants may be issued, transferred, exchanged, exercised and canceled;

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

               ARTICLE I ISSUANCE OF WARRANTS AND FORM, EXECUTION,
                DELIVERY AND REGISTRATION OF WARRANT CERTIFICATES

        Section 1.1     Issuance of Warrants. Each Warrant shall represent the
right, subject to the provisions contained herein and therein, to purchase
[________] Warrant Securities [in the aggregate principal amount of $_____] at
the Exercise Price set forth in Section 2.1. [If Securities and Warrants are to
be offered together: Warrants shall be issued in units with the Offered
Securities [If Warrants are not immediately detachable: and shall not be
separately transferable [Unless Warrants are not detachable: before [________
__, ____] (the "Detachment Date")]].] [If Warrants are to be offered separately:
Warrants shall be issued as a separate security and shall be transferable from
and after the date of issuance.] [If Warrants are to be offered in Book-Entry
form: [All] [A portion] of the Warrants shall initially be represented by one or
more global certificates (each, a "Global Warrant Certificate").] [If Securities
and Warrants are to be offered together and in definitive form: Each Warrant
Certificate included in such a unit shall evidence [_______] Warrants for each
[$_____ principal amount of] [_______] Offered Securities included in such
unit.] [If Warrants are to be offered separately and in definitive form: Each
Warrant Certificate shall evidence [_______] Warrants.]

        Section 1.2     Form, Execution and Delivery of Warrant Certificates.

                (a)     One or more Warrant Certificates evidencing Warrants to
                        purchase not more than [____] [$_______ in aggregate
                        principal amount of] Warrant Securities (except as
                        provided in Sections 1.3, 1.4 and 2.3(e)) may be
                        executed by the Company and delivered to the Warrant
                        Agent upon the execution of this Warrant Agreement or
                        from time to time thereafter [, including upon the
                        Detachment Date].

                (b)     Each Warrant Certificate, whenever issued, shall be in
                        registered form substantially in the form set forth in
                        Exhibit A hereto, with such appropriate insertions,
                        omissions, substitutions and other variations as are
                        required or permitted by this Agreement. [If Warrants
                        are issued in Book-Entry form: Each Global Warrant
                        Certificate shall bear such legend or legends as may be
                        required by the Depositary in order for it to accept the
                        Warrants for its book-entry settlement system.] Each
                        Warrant Certificate shall be printed, lithographed,
                        typewritten, mimeographed or engraved on steel engraved
                        borders or otherwise reproduced in any other manner as
                        may be approved by the officers executing the same (such
                        execution to be conclusive evidence of such approval)
                        and may have such letters, numbers or other marks of
                        identification or designation and such legends or
                        endorsements printed, lithographed or engraved thereon
                        as the officers of the Company executing the same may
                        approve (such execution to be conclusive evidence of
                        such approval) and as are not inconsistent with the
                        provisions of this Agreement, or as may be required to
                        comply with any law or with any rule or regulation made
                        pursuant thereto, or with

                                       2
<PAGE>   6

                        any regulation of any stock exchange on which the
                        Warrants [If Securities and Warrants are to be offered
                        together: , the Offered Securities] or the Warrant
                        Securities may be listed, or to conform to usage. Each
                        Warrant Certificate shall be signed on behalf of the
                        Company by its Chairman of the Board, President or any
                        Senior Vice President. The signature of any such officer
                        on any Warrant Certificate may be manual or facsimile.
                        Each Warrant Certificate, when so signed on behalf of
                        the Company, shall be delivered to the Warrant Agent
                        together with an order for the countersignature and
                        delivery of such Warrants.

                (c)     The Warrant Agent shall, upon receipt of any Warrant
                        Certificate duly executed on behalf of the Company,
                        countersign such Warrant Certificate and deliver such
                        Warrant Certificate to or upon the order of the Company.
                        Each Warrant Certificate shall be dated the date of its
                        countersignature.

                (d)     No Warrant Certificate shall be entitled to any benefit
                        under this Agreement or be valid or obligatory for any
                        purpose, and no Warrant evidenced thereby may be
                        exercised, unless such Warrant Certificate has been
                        countersigned by the manual signature of the Warrant
                        Agent. Such signature by the Warrant Agent upon any
                        Warrant Certificate executed by the Company shall be
                        conclusive evidence that such Warrant Certificate has
                        been duly issued under the terms of this Agreement.

                (e)     If any officer of the Company who has signed any Warrant
                        Certificate either manually or by facsimile signature
                        shall cease to be such officer before such Warrant
                        Certificate shall have been countersigned and delivered
                        by the Warrant Agent, such Warrant Certificate
                        nevertheless may be countersigned and delivered as
                        though the person who signed such Warrant Certificate
                        had not ceased to be such officer of the Company; and
                        any Warrant Certificate may be signed on behalf of the
                        Company by such persons as, at the actual date of the
                        execution of such Warrant Certificate, shall be the
                        proper officers of the Company as specified in this
                        Section 1.2, regardless of whether at the date of the
                        execution of this Agreement any such person was such
                        officer.

                (f)     The Holders shall [If Warrants are to be issued in
                        Book-Entry form: , except as stated below with respect
                        to Warrants evidenced by a Global Warrant Certificate,]
                        be entitled to receive Warrants in physical,
                        certificated form.

                        [If Warrants are to be issued in Book-Entry form: (g) A
                        Global Warrant Certificate may be exchanged for a new
                        Global Warrant Certificate, or one or more new Global
                        Warrant Certificates may be issued, to reflect the
                        issuance by the Company of additional Warrants. To
                        effect such an exchange, the Company shall deliver to
                        the Warrant Agent one or more new Global Warrant
                        Certificates duly executed on behalf of the Company as
                        provided in Section 1.2. The Warrant Agent shall
                        authenticate each new Global Warrant Certificate as
                        provided in Section 1.2 and shall deliver each new
                        Global Warrant Certificate to the Depositary. The
                        Warrant Agent shall cancel each Global Warrant
                        Certificate delivered to it by the Depositary in
                        exchange therefor, if any.]

                                       3
<PAGE>   7

        Section 1.3     Transfer of Warrants.

                ( )     [If Warrants are to be issued in Book-Entry form: (a)
                        [All] [A portion] of the Warrants shall initially be
                        represented by one or more Global Warrant Certificates
                        deposited with [the Depositary Trust Company] (the
                        "Depositary") and registered in the name of [Cede &
                        Co.], a nominee of the Depositary. The Depositary, or
                        such other entity as is agreed to by the Depositary, may
                        hold each Global Warrant Certificate as custodian for
                        Depositary. Except as provided for in Section 1.3(b)
                        hereof, no person acquiring Warrants traded on any
                        securities exchange with book-entry settlement through
                        the Depositary shall receive or be entitled to receive
                        physical delivery of definitive Warrant Certificates
                        evidencing such Warrants. Ownership of beneficial
                        interests in the Warrants shall be shown on, and the
                        transfer of such ownership shall be effected through,
                        records maintained by (i) the Depositary or its nominee
                        for each Global Warrant Certificate, or (ii)
                        institutions that have accounts with the Depositary
                        (such institution, with respect to a Warrant in its
                        account, a "Participant").]

                ( )     [If Warrants are to be issued in Book-Entry form: (b)
                        If the Depositary subsequently ceases to make its
                        book-entry settlement system available for the Warrants,
                        the Company may instruct the Warrant Agent regarding
                        making other arrangements for book-entry settlement. In
                        the event that the receipts are not eligible for, or it
                        is no longer necessary to have the Warrants available
                        in, book-entry form, the Warrant Agent shall provide
                        written instructions to the Depositary to deliver to the
                        Warrant Agent for cancellation each Global Warrant
                        Certificate, and the Company shall instruct the Warrant
                        Agent to deliver to the Depositary definitive Warrant
                        Certificates in physical form evidencing such Warrants.
                        Such definitive Warrant Certificates shall be in the
                        form annexed hereto as Exhibit A with appropriate
                        insertions, modifications and omissions, as provided
                        above.]

                ( )     [If Securities and Warrants are to be offered
                        together: (c) [If Warrants are not immediately
                        detachable: Prior to the Detachment Date,] Warrants may
                        be transferred or exchanged only together with the
                        Offered Security to which such Warrant is attached, and
                        only for the purpose of effecting, or in conjunction
                        with, a transfer or exchange of such Offered Security.
                        Furthermore, [If Warrants are not immediately
                        detachable: on or prior to the Detachment Date,] each
                        transfer of an Offered Security on the register relating
                        to such Offered Securities shall operate also to
                        transfer the Warrants to which such Offered Security was
                        initially attached. [If Warrants are not immediately
                        detachable: From and after the Detachment Date, the
                        above provisions shall be of no further force and
                        effect.]

                ( )     A Warrant Certificate may be transferred at the option
                        of the Holder thereof upon surrender of such Warrant
                        Certificate at the corporate trust office of the Warrant
                        Agent, properly endorsed or accompanied by appropriate
                        instruments of transfer and written instructions for
                        transfer, all in form satisfactory to the Company and
                        the Warrant Agent [If Warrants

                                       4
<PAGE>   8

                        are to be issued in Book-Entry form: ; provided,
                        however, that except as otherwise provided herein or in
                        any Global Warrant Certificate, each Global Warrant
                        Certificate may be transferred only in whole and only to
                        the Depositary, to another nominee of the Depositary, to
                        a successor depository, or to a nominee of a successor
                        depository]. Upon any such registration of transfer, the
                        Company shall execute, and the Warrant Agent shall
                        countersign and deliver, as provided in Section 1.2, in
                        the name of the designated transferee a new Warrant
                        Certificate or Warrant Certificates of any authorized
                        denomination evidencing in the aggregate a like number
                        of unexercised Warrants.

                ( )     [If Warrants are not immediately detachable: After the
                        Detachment Date,] Upon surrender at the corporate office
                        of the Warrant Agent, properly endorsed or accompanied
                        by appropriate instruments of transfer and written
                        instructions for such exchange, all in form satisfactory
                        to the Company and the Warrant Agent, one or more
                        Warrant Certificates may be exchanged for one or more
                        Warrant Certificates in any other authorized
                        denominations; provided that such new Warrant
                        Certificate(s) evidence the same aggregate number of
                        Warrants as the Warrant Certificate(s) so surrendered.
                        Upon any such surrender for exchange, the Company shall
                        execute, and the Warrant Agent shall countersign and
                        deliver, as provided in Section 1.2, in the name of the
                        Holder of such Warrant Certificates, the new Warrant
                        Certificates.

                ( )     The Warrant Agent shall keep, at its corporate trust
                        office, books in which, subject to such reasonable
                        regulations as it may prescribe, it shall register
                        Warrant Certificates in accordance with Section 1.2 and
                        transfers, exchanges, exercises and cancellations of
                        outstanding Warrant Certificates. Whenever any Warrant
                        Certificates are surrendered for transfer or exchange in
                        accordance with this Section 1.3, an authorized officer
                        of the Warrant Agent shall manually countersign and
                        deliver the Warrant Certificates which the Holder making
                        the transfer or exchange is entitled to receive.

                ( )     No service charge shall be made for any transfer or
                        exchange of Warrant Certificates, but the Company may
                        require payment of a sum sufficient to cover any stamp
                        or other tax or other governmental charge that may be
                        imposed in connection with any such transfer or
                        exchange.

        Section 1.4     Lost, Stolen, Mutilated or Destroyed Warrant
Certificates. Upon receipt by the Company and the Warrant Agent of evidence
satisfactory to them of the ownership of and the loss, theft, destruction or
mutilation of any Warrant Certificate and of indemnity satisfactory to them and,
in the case of mutilation, upon surrender of such Warrant Certificate to the
Warrant Agent for cancellation, then, in the absence of notice to the Company or
the Warrant Agent that such Warrant Certificate has been acquired by a bona fide
purchaser, the Company shall execute, and an authorized officer of the Warrant
Agent shall manually countersign and deliver, in exchange for or in lieu of the
lost, stolen, destroyed or mutilated Warrant Certificate, a new Warrant
Certificate of the same tenor and for a like number of Warrants. No service
charge shall be made for any replacement of Warrant Certificates, but the
Company may require the payment of a sum sufficient to cover any stamp or other
tax or other governmental charge that may be

                                       5
<PAGE>   9

imposed in connection with any such exchange. To the extent permitted under
applicable law, the provisions of this Section 1.4 are exclusive with respect to
the replacement of mutilated, lost, stolen or destroyed Warrant Certificates and
shall preclude any and all other rights or remedies.

        Section 1.5     Cancellation of Warrant Certificates. Any Warrant
Certificate surrendered to the Warrant Agent for transfer, exchange or exercise
of the Warrants evidenced thereby shall be promptly canceled by the Warrant
Agent and shall not be reissued and, except as expressly permitted by this
Agreement, no Warrant Certificate shall be issued hereunder in lieu thereof. The
Warrant Agent shall deliver to the Company from time to time or otherwise
dispose of canceled Warrant Certificates in a manner satisfactory to the
Company. Any Warrant Certificate surrendered to the Company for transfer,
exchange or exercise of the Warrants evidenced thereby shall be promptly
delivered to the Warrant Agent and such transfer, exchange or exercise shall not
be effective until such Warrant Certificate has been received by the Warrant
Agent.

        Section 1.6     Treatment of Holders [If Warrants are to be issued in
Book-Entry Form and Beneficial Owners:] of Warrant Certificates. (a) The term
"Holder", as used herein, shall mean any person in whose name at the time any
Warrant Certificate shall be registered upon the books to be maintained by the
Warrant Agent for that purpose [If Warrants are not immediately detachable are
offered: or, prior to the Detachment Date, the person in whose name the Offered
Security to which such Warrant Certificate was initially attached is registered
upon the register relating to such Offered Securities. At all times prior to the
Detachment Date, the Company will, or will cause the registrar of the Offered
Securities to, make available to the Warrant Agent such information as to
holders of the Offered Securities as may be necessary to keep the Warrant
Agent's records current]. [If Warrants are to be issued in Book-Entry form: The
Holder of each Global Warrant Certificate shall initially be [Cede & Co.], a
nominee of the Depositary.]

                ( )     [If Warrants are to be issued in Book-Entry Form: (b)
                        The term "Beneficial Owner" as used herein shall mean
                        any person in whose name ownership of beneficial
                        interests in Warrants evidenced by a Global Warrant
                        Certificate is recorded in the records maintained by the
                        Depositary or its nominee, or by a Participant [If
                        Securities and Warrants that are not immediately
                        detachable are offered:, or, prior to the Detachment
                        Date, the person in whose name the Offered Security to
                        which such Warrant Certificate was initially attached is
                        registered upon the register relating to such Offered
                        Securities].]

                ( )     Every Holder [If Warrants are to be issued in
                        Book-Entry form: and every Beneficial Owner] consents
                        and agrees with the Company, the Warrant Agent and with
                        every subsequent Holder [If Warrants are to be issued in
                        Book-Entry form: and Beneficial Owner] that until the
                        Warrant Certificate is transferred on the books of the
                        Warrant Agent, the Company and the Warrant Agent may
                        treat the registered Holder of such Warrant Certificate
                        as the absolute owner of the Warrants evidenced thereby
                        for any purpose and as the person entitled to exercise
                        the rights attaching to the Warrants evidenced thereby,
                        any notice to the contrary notwithstanding.

                                       6
<PAGE>   10

                                   ARTICLE II
                EXERCISE PRICE, DURATION AND EXERCISE OF WARRANTS

        Section 2.1     Exercise Price. The exercise price of each Warrant shall
be [$________] (the "Exercise Price") [modify as appropriate to reflect terms of
offered Warrants].

        Section 2.2     Duration of Warrants. [Subject to the limitations set
forth herein,] Each Warrant may be exercised in whole but not in part [Unless
Warrants may be exercised on only one date:] on any Business Day (as defined
below) occurring during the period (the "Exercise Period") commencing on [its
date of issuance] [_________ __, ____] and ending at 5:00 P.M., New York time,]
on [__________ __, ____] (the "Expiration Date"). Each Warrant remaining
unexercised after 5:00 P.M., New York time, on the Expiration Date shall become
void, and all rights of the Holder under this Agreement shall cease.

                As used herein, the term "Business Day" means any day which is
not a Saturday or Sunday and is not a legal holiday or a day on which banking
institutions generally are authorized or obligated by law or regulation to close
in New York.

        Section 2.3     Exercise of Warrants.

                (a)     A Holder may exercise a Warrant by delivering, not later
                        than 5:00 P.M., New York time, on [Unless Warrants may
                        be exercised on only one date: any Business Day during
                        the Exercise Period (the "Exercise Date")] [If Warrants
                        may be exercised on only one date: the Expiration Date]
                        to the Warrant Agent at its corporate trust department
                        (i) the Warrant Certificate evidencing the Warrants to
                        be exercised, [If Warrants are to be issued in
                        Book-Entry form: and, in the case of a Global Warrant
                        Certificate, the Warrants to be exercised (the
                        "Book-Entry Warrants") free on the records of the
                        Depositary to an account of the Warrant Agent at the
                        Depositary designated for such purpose in writing by the
                        Warrant Agent to the Depositary from time to time,] (ii)
                        an election to purchase the Warrant Securities
                        ("Election to Purchase"), [For definitive Warrant
                        Certificates: properly completed and executed by the
                        Holder on the reverse of the Warrant Certificate] [If
                        Warrants are to be issued in Book-Entry form: or, in the
                        case of a Global Warrant Certificate, properly executed
                        by the Participant and substantially in the form
                        included on the reverse of each Warrant Certificate,]
                        and (iii) the Exercise Price for each Warrant to be
                        exercised in lawful money of the United States of
                        America by certified or official bank check or by bank
                        wire transfer in immediately available funds. If any of
                        (a) the Warrant Certificate [If Warrants are to be
                        issued in Book-Entry form: or the Book-Entry Warrants,]
                        (b) the Election to Purchase, or (c) the Exercise Price
                        therefor, is received by the Warrant Agent after 5:00
                        P.M., New York time, on [Unless Warrants may be
                        exercised on only one date: the specified Exercise Date,
                        the Warrants will be deemed to be received and exercised
                        on the Business Day next succeeding the Exercise Date.
                        If the date specified as the Exercise Date is not a
                        Business Day, the Warrants will be deemed to be received
                        and exercised on the next succeeding day which is a
                        Business Day. If the Warrants are received or deemed to
                        be received after] the Expiration Date, the exercise
                        thereof will be null and void and any funds delivered to
                        the Warrant Agent will be returned to the Holder [If
                        Warrants are to be issued in Book-Entry form: or
                        Participant, as the case may be,] as soon as

                                       7
<PAGE>   11

                        practicable. In no event will interest accrue on funds
                        deposited with the Warrant Agent in respect of an
                        exercise or attempted exercise of Warrants. The validity
                        of any exercise of Warrants will be determined by the
                        Warrant Agent in its sole discretion and such
                        determination will be final and binding upon the Holder
                        and the Company. Neither the Company nor the Warrant
                        Agent shall have any obligation to inform a Holder of
                        the invalidity of any exercise of Warrants. The Warrant
                        Agent shall deposit all funds received by it in payment
                        of the Exercise Price in the account of the Company
                        maintained with the Warrant Agent for such purpose and
                        shall advise the Company by telephone at the end of each
                        day on which funds for the exercise of the Warrants are
                        received of the amount so deposited to its account. The
                        Warrant Agent shall promptly confirm such telephonic
                        advice to the Company in writing.

                (b)     The Warrant Agent shall, by 11:00 A.M. on the Business
                        Day following the [Unless Warrants may be exercised on
                        only one date: Exercise Date of any Warrant] [If
                        Warrants may be exercised on only one date: Expiration
                        Date], advise the Company and the [Trustee under the
                        Indenture applicable to] [the transfer agent and
                        registrar in respect of] the Warrant Securities issuable
                        upon such exercise as to the number of Warrants
                        exercised in accordance with the terms and conditions of
                        this Agreement, the instructions of each Holder [If
                        Warrants are to be issued in Book-entry Form: or
                        Participant, as the case may be,] with respect to
                        delivery of the Warrant Securities issuable upon such
                        exercise, and the delivery of definitive Warrant
                        Certificates [If Warrants are to be issued in Book-Entry
                        form: or one or more Global Warrant Certificates, as
                        appropriate,] evidencing the balance, if any, of the
                        Warrants remaining after such exercise, and such other
                        information as the Company or such [Trustee] [transfer
                        agent and registrar] shall reasonably require.

                (c)     Subject to satisfaction of the conditions set forth in
                        Sections 2.3(a) and 2.3(b) above, the Company shall, by
                        5:00 P.M., New York time, on the third Business Day next
                        succeeding the [Unless Warrants may be exercised on only
                        one date: Exercise Date of any Warrant] [If Warrants may
                        be exercised on only one date: Expiration Date],
                        execute, issue and deliver to the Warrant Agent,
                        [pursuant to the Indenture applicable to the Warrant
                        Securities, the Warrant Securities, duly authenticated
                        by the Trustee of such Indenture and in authorized
                        denominations] [the Warrant Securities] to which such
                        Holder is entitled, in fully registered form, registered
                        in such name or names as may be directed by such Holder
                        [If Warrants are to be issued in Book-Entry form: or the
                        Participant, as the case may be]. Upon receipt of such
                        Warrant Securities, the Warrant Agent shall, by 5:00
                        P.M., New York time, on the fifth Business Day next
                        succeeding [Unless Warrants may be exercised on only one
                        date: such Exercise Date] [If Warrants may be exercised
                        on only one date: the Expiration Date], transmit such
                        Warrant Securities, to or upon the order of the Holder
                        [If Warrants are to be issued in Book-Entry form: or
                        Participant, as the case may be,] together with, or
                        preceded by the prospectus referred to in Section 5.6
                        hereof. The Company agrees that it

                                       8
<PAGE>   12

                        will provide such information and documents to the
                        Warrant Agent as may be necessary for the Warrant Agent
                        to fulfill its obligations hereunder.

                (d)     The accrual of [interest] [dividends], if any, on the
                        Warrant Securities issued upon the valid exercise of any
                        Warrant will be governed by the terms of the applicable
                        [Indenture] [certificate of designations and the Amended
                        and Restated Certificate of Incorporation of the Company
                        (the "Certificate of Incorporation")] and such Warrant
                        Securities. From and after the issuance of such Warrant
                        Securities, the former Holder of the Warrants exercised
                        will be entitled to the benefits of the [Indenture]
                        [certificate of designations and the Certificate of
                        Incorporation] under which such Warrant Securities are
                        issued and such former Holder's right to receive
                        payments of [principal of (and premium, if any) and
                        interest, if any, on] [dividends and any other amounts
                        payable in respect of] the Warrant Securities shall be
                        governed by, and shall be subject to, the terms and
                        provisions of such [Indenture] [certificate of
                        designations and Certificate of Incorporation] and the
                        Warrant Securities.

                (e)     Warrants may be exercised only in whole numbers of
                        Warrants. [Unless Warrants may be exercised on only one
                        date: If fewer than all of the Warrants evidenced by a
                        Warrant Certificate are exercised, a new Warrant
                        Certificate for the number of Warrants remaining
                        unexercised shall be executed by the Company and
                        countersigned by the Warrant Agent as provided in
                        Section 1.2 hereof, and delivered to the Holder at the
                        address specified on the books of the Warrant Agent or
                        as otherwise specified by such Holder.]

                (f)     The Company shall not be required to pay any stamp or
                        other tax or other governmental charge required to be
                        paid in connection with any transfer involved in the
                        issue of the Warrant Securities; and in the event that
                        any such transfer is involved, the Company shall not be
                        required to issue or deliver any Warrant Securities
                        until such tax or other charge shall have been paid or
                        it has been established to the Company's satisfaction
                        that no such tax or other charge is due.

        Section 2.4     Cancellation. The Warrant Agent and no one else shall
cancel all Warrant Certificates surrendered for registration of transfer,
exchange, exercise, replacement or cancellation and shall destroy cancelled
Warrant Certificates (subject to the record retention requirement of the
Exchange Act of 1934). Certification of the destruction of all cancelled Warrant
Certificates shall be delivered to the Company.

        [If Warrants for Class A Common Stock are offered: Section 2.5.
Adjustment Under Certain Circumstances. The Exercise Price and the number of
Warrant Securities purchasable upon the exercise of each Warrant shall be
subject to adjustment upon (i) the issuance of a stock dividend to the holders
of the outstanding shares of Warrant Securities or a combination, subdivision or
reclassification of the Warrant Securities; (ii) the issuance of rights,
warrants or options to all holders of the Warrant Securities entitling the
holders thereof to purchase Warrant Securities for an aggregate consideration
per share less than the current market price per share of the Warrant
Securities; or (iii) any distribution by the Company to the holders of the
Warrant

                                       9
<PAGE>   13

Securities of evidences of indebtedness of the Company or of assets (excluding
cash dividends or distributions payable out of consolidated earnings and earned
surplus and dividends or distributions referred to in (i) above); provided that
no such adjustment in the number of Warrant Securities purchasable upon exercise
of the Warrants will be required until cumulative adjustments require an
adjustment of at least 1% of such number. No fractional shares will be issued
upon exercise of Warrants, but the Company will pay the cash value of any
fractional shares otherwise issuable. The adjustments to be made under this
Section 2.5 shall be determined by the Warrant Agent and such determination
shall be final and binding upon the Holders and the Company.]

                                  ARTICLE III
                 OTHER PROVISIONS RELATING TO RIGHTS OF HOLDERS
                [IF WARRANTS ARE TO BE ISSUED IN BOOK-ENTRY FORM:
                       AND BENEFICIAL OWNERS] OF WARRANTS

        Section 3.1     No Rights as Holders of Warrant Securities Conferred by
Warrants or Warrant Certificates. No Warrant Certificate or Warrant evidenced
thereby shall entitle the Holder thereof to any of the rights of a holder of any
Warrant Securities, including, without limitation, [the right to receive the
payments of principal of (and premium, if any) and interest, if any, on Debt
Securities purchasable upon such exercise or to enforce any of the covenants in
the Indenture] [the right to receive dividends, if any, or payments upon the
liquidation, dissolution or winding up of the Company or to exercise voting
rights, if any].

        Section 3.2     Holder [If Warrants are to be issued in Book-Entry form:
and Beneficial Owner] of Warrant May Enforce Rights. Notwithstanding any of the
provisions of this Agreement, any Holder [If Warrants are to be issued in
Book-Entry form: and any Beneficial Owner] of any Warrant, without the consent
of the Warrant Agent or the Holder of any Warrant, may, on such Holder's [If
Warrants are to be issued in Book-Entry form: or Beneficial Owner's] own behalf
and for his own benefit, enforce, and may institute and maintain any suit,
action or proceeding against the Company to enforce, or otherwise in respect of,
such Holder's [If Warrants are to be issued in Book-Entry form: or Beneficial
Owner's] right to exercise the Warrants evidenced by any Warrant Certificate in
the manner provided in this Agreement and such Warrant Certificate.

                                   ARTICLE IV
                          CONCERNING THE WARRANT AGENT

        Section 4.1     Warrant Agent. The Company hereby appoints
[______________] as Warrant Agent of the Company in respect of the Warrants upon
the terms and subject to the conditions herein set forth, and [____________]
hereby accepts such appointment. The Warrant Agent shall have the powers and
authority granted to and conferred upon it hereby and such further powers and
authority to act on behalf of the Company as the Company may hereafter grant to
or confer upon it.

        Section 4.2     Limitations on Warrant Agent's Obligations. The Warrant
Agent accepts its obligations herein set forth upon the terms and conditions
hereof, including the following, to all of which the Company agrees and to all
of which the rights hereunder of the Holders from time to time shall be subject:

                                       10
<PAGE>   14

                (a)     Compensation and Indemnification. The Company agrees to
                        pay the Warrant Agent compensation to be agreed upon
                        with the Company for all services rendered by the
                        Warrant Agent and to reimburse the Warrant Agent for all
                        reasonable out-of-pocket expenses (including reasonable
                        counsel fees) incurred by the Warrant Agent in
                        connection with the services rendered by it hereunder.
                        The Company also agrees to indemnify the Warrant Agent
                        for, and to hold it harmless against, any loss,
                        liability or expense incurred without negligence, bad
                        faith or breach of this Agreement on the part of the
                        Warrant Agent, arising out of or in connection with its
                        acting as Warrant Agent hereunder.

                (b)     Agent for the Company. In acting in the capacity of
                        Warrant Agent under this Agreement, the Warrant Agent is
                        acting solely as agent of the Company and does not
                        assume any obligation or relationship of agency or trust
                        with any of the owners or holders of the Warrants except
                        as expressly set forth herein.

                (c)     Counsel. The Warrant Agent may consult with counsel
                        satisfactory to it (which may be counsel to the
                        Company), and the advice of such 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 accordance with the advice of such
                        counsel.

                (d)     Documents. The Warrant Agent shall be protected and
                        shall incur no liability for or in respect of any action
                        taken or thing suffered by it in reliance upon any
                        notice, direction, consent, certificate, affidavit,
                        statement or other paper or document reasonably believed
                        by it to be genuine and to have been presented or signed
                        by the proper parties.

                (e)     Certain Transactions. The Warrant Agent, and its
                        officers, directors and employees, may become the owner
                        of, or acquire any interest in, any Warrant, with the
                        same rights that it or they would have were it not the
                        Warrant Agent hereunder, and, to the extent permitted by
                        applicable law, it or they may engage or be interested
                        in any financial or other transaction with the Company
                        and may act on, or as a depositary, trustee or agent
                        for, any committee or body of holders of Warrants [If
                        Securities and Warrants are being offered together:,
                        Offered Securities] or Warrant Securities, or other
                        securities or obligations of the Company as freely as if
                        it were not the Warrant Agent hereunder. Nothing in this
                        Agreement shall be deemed to prevent the Warrant Agent
                        from acting as trustee under either Indenture.

                (f)     No Liability for Interest. The Warrant Agent shall not
                        be under any liability for interest on any monies at any
                        time received by it pursuant to any of the provisions of
                        this Agreement.

                (g)     No Liability for Invalidity. The Warrant Agent shall not
                        be under any responsibility with respect to the validity
                        or sufficiency of this Agreement or the execution and
                        delivery hereof (except the due execution and

                                       11
<PAGE>   15

                        delivery hereof by the Warrant Agent) or with respect to
                        the validity or execution of the Warrant Certificates
                        (except its countersignature thereon).

                (h)     No Responsibility for Recitals. The recitals contained
                        herein and in the Warrant Certificates (except as to the
                        Warrant Agent's countersignature thereon) shall be taken
                        as the statements of the Company and the Warrant Agent
                        assumes no responsibility hereby for the correctness of
                        the same.

                (i)     No Implied Obligations. The Warrant Agent shall be
                        obligated to perform such duties as are specifically set
                        forth herein and no implied duties or obligations shall
                        be read into this Agreement against the Warrant Agent.
                        The Warrant Agent shall not be under any obligation to
                        take any action hereunder which may tend to involve it
                        in any expense or liability, the payment of which within
                        a reasonable time is not, in its opinion, assured to it.
                        The Warrant Agent shall not be accountable or under any
                        duty or responsibility for the use by the Company of any
                        Warrant Certificate authenticated by the Warrant Agent
                        and delivered by it to the Company pursuant to this
                        Agreement or for the application by the Company of the
                        proceeds of the issue and sale, or exercise, of the
                        Warrants. The Warrant Agent shall have no duty or
                        responsibility in case of any default by the Company in
                        the performance of its covenants or agreements contained
                        herein or in any Warrant Certificate or in the case of
                        the receipt of any written demand from a Holder with
                        respect to such default, including, without limiting the
                        generality of the foregoing, any duty or responsibility
                        to initiate or attempt to initiate any proceedings at
                        law or otherwise or, except as provided in Section 5.3
                        hereof, to make any demand upon the Company.

        Section 4.3     Compliance With Applicable Laws. The Warrant Agent
agrees to comply with all applicable federal and state laws imposing obligations
on it in respect of the services rendered by it under this Agreement and in
connection with the Warrants, including (but not limited to) the provisions of
United States federal income tax laws regarding information reporting and backup
withholding. The Warrant Agent expressly assumes all liability for its failure
to comply with any such laws imposing obligations on it, including (but not
limited to) any liability for its failure to comply with any applicable
provisions of United States federal income tax laws regarding information
reporting and backup withholding.

        Section 4.4     Resignation and Appointment of Successor.

                (a)     The Company agrees, for the benefit of the Holders from
                        time to time, that there shall at all times be a Warrant
                        Agent hereunder until all the Warrants issued hereunder
                        have been exercised or have expired in accordance with
                        their terms, which Warrant Agent shall be a bank or
                        trust company organized under the laws of the United
                        States of America or one of the states thereof, which is
                        authorized under the laws of the jurisdiction of its
                        organization to exercise corporate trust powers, has a
                        combined capital and surplus of at least $50,000,000 and
                        has an office or an agent's office in the United States
                        of America.

                                       12
<PAGE>   16

                (b)     The Warrant Agent may at any time resign as such agent
                        by giving written notice to the Company of such
                        intention on its part, specifying the date on which it
                        desires such resignation to become effective; provided
                        that such date shall not be less than three months after
                        the date on which such notice is given, unless the
                        Company agrees to accept such notice less than three
                        months prior to such date of effectiveness. The Company
                        may remove the Warrant Agent at any time by giving
                        written notice to the Warrant Agent of such removal,
                        specifying the date on which it desires such removal to
                        become effective. Such resignation or removal shall take
                        effect upon the appointment by the Company, as
                        hereinafter provided, of a successor Warrant Agent
                        (which shall be a bank or trust company qualified as set
                        forth in Section 4.4(a)) and the acceptance of such
                        appointment by such successor Warrant Agent. The
                        obligation of the Company under Section 4.2(a) shall
                        continue to the extent set forth therein notwithstanding
                        the resignation or removal of the Warrant Agent.

                (c)     If at any time the Warrant Agent shall resign, or shall
                        cease to be qualified as set forth in Section 4.4(a), or
                        shall be removed, or shall become incapable of acting,
                        or shall be adjudged a bankrupt or insolvent, or shall
                        file a petition seeking relief under any applicable
                        Federal or State bankruptcy or insolvency law or similar
                        law, or make an assignment for the benefit of its
                        creditors or consent to the appointment of a receiver,
                        conservator or custodian of all or any substantial part
                        of its property, or shall admit in writing its inability
                        to pay or to meet its debts as they mature, or if a
                        receiver or custodian of it or of all or any substantial
                        part of its property shall be appointed, or if an order
                        of any court shall be entered for relief against it
                        under the provisions of any applicable Federal or State
                        bankruptcy or similar law, or if any public officer
                        shall have taken charge or control of the Warrant Agent
                        or of its property or affairs, for the purpose of
                        rehabilitation, conservation or liquidation, a successor
                        Warrant Agent, qualified as set forth in Section 4.4(a),
                        shall be appointed by the Company by an instrument in
                        writing, filed with the successor Warrant Agent. Upon
                        the appointment as herein provided of a successor
                        Warrant Agent and acceptance by the latter of such
                        appointment, the Warrant Agent so superseded shall cease
                        to be Warrant Agent under this Agreement.

                (d)     Any successor Warrant Agent appointed under this
                        Agreement shall execute, acknowledge and deliver to its
                        predecessor and to the Company an instrument accepting
                        such appointment, and thereupon such successor Warrant
                        Agent, without any further act, deed or conveyance,
                        shall become vested with all the authority, rights,
                        powers, trusts, immunities, duties and obligations of
                        such predecessor with like effect as if originally named
                        as Warrant Agent under this Agreement, and such
                        predecessor, upon payment of its charges and
                        disbursements then unpaid, shall thereupon become
                        obligated to transfer, deliver and pay over, and such
                        successor Warrant Agent shall be entitled to receive,
                        all monies, securities and other property on deposit
                        with or held by such predecessor, as Warrant Agent under
                        this Agreement.

                                       13
<PAGE>   17

                (e)     Any corporation into which the Warrant Agent may be
                        merged or converted or any corporation with which the
                        Warrant Agent may be consolidated, or any corporation
                        resulting from any merger, conversion or consolidation
                        to which the Warrant Agent shall be a party, or any
                        corporation to which the Warrant Agent shall sell or
                        otherwise transfer all or substantially all the assets
                        and business of the Warrant Agent, in each case provided
                        that it shall be qualified as set forth in Section
                        4.4(a), shall be the successor Warrant Agent under this
                        Agreement without the execution or filing of any paper
                        or any further act on the part of any of the parties to
                        this Agreement, including, without limitation, any
                        successor to the Warrant Agent first named above.

                                    ARTICLE V
                                  MISCELLANEOUS

        Section 5.1     Amendments.

                (a)     This Agreement and any Warrant Certificate may be
                        amended by the parties hereto by executing a
                        supplemental warrant agreement (a "Supplemental
                        Agreement"), without the consent of the Holder of any
                        Warrant, for the purpose of (i) curing any ambiguity, or
                        curing, correcting or supplementing any defective
                        provision contained herein, or making any other
                        provisions with respect to matters or questions arising
                        under this Agreement that is not inconsistent with the
                        provisions of this Agreement or the Warrant
                        Certificates, (ii) evidencing the succession of another
                        corporation to the Company and the assumption by any
                        such successor of the covenants of the Company contained
                        in this Warrant Agreement and the Warrants, (iii)
                        evidencing and providing for the acceptance of
                        appointment by a successor Warrant Agent with respect to
                        the Warrants, [If Warrants are to be issued in
                        Book-Entry form: (iv) evidencing and providing for the
                        acceptance of appointment by a successor Depositary with
                        respect to each Global Warrant Certificate, (v) issuing
                        definitive Warrant Certificates in accordance with
                        paragraph (b) of Section 1.3,] (vi) adding to the
                        covenants of the Company for the benefit of the Holders
                        or surrendering any right or power conferred upon the
                        Company under this Agreement, or (vii) amending this
                        Agreement and the Warrants in any manner that the
                        Company may deem to be necessary or desirable and that
                        will not adversely affect the interests of the Holders
                        in any material respect.

                (b)     The Company and the Warrant Agent may amend this
                        Agreement and the Warrants by executing a Supplemental
                        Agreement with the consent of the Holders of not fewer
                        than a majority of the unexercised Warrants affected by
                        such amendment, for the purpose of adding any provisions
                        to or changing in any manner or eliminating any of the
                        provisions of this Agreement or of modifying in any
                        manner the rights of the Holders under this Agreement;
                        provided, however, that, without the consent of each
                        Holder of Warrants affected thereby, no such amendment
                        may be made that (i) changes the Warrants so as to
                        reduce the [principal amount]

                                       14
<PAGE>   18

                        [number] of Warrant Securities purchasable upon exercise
                        of the Warrants or so as to increase the exercise price
                        [If Warrants for Class A Common Stock are offered:
                        (other than as provided by Section 2.3)], (ii) shortens
                        the period of time during which the Warrants may be
                        exercised, (iii) otherwise adversely affects the
                        exercise rights of the Holders in any material respect,
                        or (iv) reduces the number of unexercised Warrants the
                        consent of the Holders of which is required for
                        amendment of this Agreement or the Warrants.

        Section 5.2     Merger, Consolidation, Sale, Lease, Transfer or
Conveyance. The Company may consolidate or merge with or into any other
corporation or sell, lease, transfer or convey all or substantially all of its
assets to any other corporation, provided that (i) either (x) the Company is the
continuing corporation or (y) the corporation (if other than the Company) that
is formed by or results from any such consolidation or merger or that receives
such assets is a corporation organized and existing under the laws of the United
States of America or a state thereof and such corporation assumes the
obligations of the Company with respect to the performance and observance of all
of the covenants and conditions of this Agreement to be performed or observed by
the Company and (ii) the Company or such successor corporation, as the case may
be, must not immediately be in default under this Agreement. If at any time
there shall be any consolidation or merger or any sale, lease, transfer,
conveyance or other disposition of all or substantially all of the assets of the
Company, then the Company or such successor or assuming corporation, as the case
may be, shall make appropriate provision by amendment of this Agreement or
otherwise so that the holders of the Warrants then outstanding shall have the
right at any time thereafter, upon exercise of such Warrants, to receive the
kind and amount of shares of stock and other securities and property or assets
receivable upon such consolidation or merger or any sale, lease, transfer,
conveyance or other disposition as would be received by a holder of the number
of Warrant Securities issuable upon exercise of such Warrant immediately prior
to such consolidation or merger or sale, lease, transfer, conveyance or other
disposition, and in any such event the successor or assuming corporation shall
succeed to and be substituted for the Company, with the same effect as if it had
been named herein and in the Warrant Certificates as the Company; the Company
shall thereupon be relieved of any further obligation hereunder or under the
Warrants, and, in the event of any such sale, lease, transfer, conveyance (other
than by way of lease) or other disposition, the Company as the predecessor
corporation may thereupon or at any time thereafter be dissolved, wound up or
liquidated. Such successor or assuming corporation thereupon may cause to be
signed, and may issue either in its own name or in the name of the Company,
Warrant Certificates evidencing the Warrants not theretofore exercised, in
exchange and substitution for the Warrant Certificates theretofore issued. Such
Warrant Certificates shall in all respects have the same legal rank and benefit
under this Agreement as the Warrant Certificates evidencing the Warrants
theretofore issued in accordance with the terms of this Agreement as though such
new Warrant Certificates had been issued at the date of the execution hereof. In
any case of any such merger or consolidation or sale, lease, transfer,
conveyance or other disposition of all or substantially all of the assets of the
Company, such changes in phraseology and form (but not in substance) may be made
in the new Warrant Certificates, as may be appropriate.

        Section 5.3     Notices and Demands to the Company and Warrant Agent.
If the Warrant Agent shall receive any notice or demand addressed to the Company
by the Holder [If Warrants are to be issued in Book-Entry form: or a
Participant, as the case may be], the Warrant Agent shall promptly forward such
notice or demand to the Company.

                                       15
<PAGE>   19

        Section 5.4     Addresses. Any communications from the Company to the
Warrant Agent with respect to this Agreement shall be addressed to
[____________________, Attention: ________________________], and any
communications from the Warrant Agent to the Company with respect to this
Agreement shall be addressed to XO Communications, Inc., 11111 Sunset Hills
Drive, Reston, Virginia 20190, Attention: Corporate Secretary (or such other
address as shall be specified in writing by the Warrant Agent or by the Company,
as the case may be). The Company or the Warrant Agent shall give notice to the
Holders of Warrants by mailing written notice by first class mail, postage
prepaid, to such Holders as their names and addresses appear in the books and
records of the Warrant Agent [or, prior to the Detachment Date, on the register
of the Offered Securities].

        Section 5.5     GOVERNING LAW. THIS AGREEMENT AND EACH WARRANT
CERTIFICATE AND ALL RIGHTS HEREUNDER AND THEREUNDER AND PROVISIONS HEREOF AND
THEREOF SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE
STATE OF NEW YORK (WITHOUT REFERENCE TO APPLICABLE CONFLICTS OF LAW PROVISIONS).

        Section 5.6     Delivery of Prospectus. The Company shall furnish to the
Warrant Agent sufficient copies of a prospectus relating to the Warrant
Securities deliverable upon exercise of Warrants and complying in all material
respects with the Securities Act of 1933, as amended (the "Prospectus"), and the
Warrant Agent agrees that upon the exercise of any Warrant, the Warrant Agent
shall deliver a Prospectus to the Holder of such Warrant, prior to or
concurrently with the delivery of the Warrant Securities issued upon such
exercise.

        Section 5.7     Obtaining of Governmental Approvals. The Company shall
from time to time take all action which may be necessary to obtain and keep
effective any and all permits, consents and approvals of governmental agencies
and authorities and securities acts filings under United States Federal and
state laws, which the Company may deem necessary or appropriate in connection
with the issuance, sale, transfer and delivery of the Warrants, the exercise of
the Warrants, the issuance, sale, transfer and delivery of the Warrant
Securities to be issued upon exercise of Warrants or upon the expiration of the
period during which the Warrants are exercisable.

        Section 5.8     Payment of Taxes. The Company will pay all stamp and
other duties, if any, to which, under the laws of the United States of America,
this Agreement or the original issuance of the Warrants may be subject.

        Section 5.9     Benefits of Warrant Agreement. Nothing in this Agreement
or any Warrant Certificate expressed or implied and nothing that may be inferred
from any of the provisions hereof or thereof is intended, or shall be construed,
to confer upon, or give to, any person or corporation other than the Company,
the Warrant Agent and their respective successors and assigns, [If Warrants are
to be issued in Book-Entry form: the Beneficial Owners] and the Holders any
right, remedy or claim under or by reason of this Agreement or any Warrant
Certificate or of any covenant, condition, stipulation, promise or agreement
hereof or thereof; and all covenants, conditions, stipulations, promises and
agreements contained in this Agreement or any Warrant Certificate shall be for
the sole and exclusive benefit of the Company and the Warrant Agent and their
respective successors and assigns and of the [If Warrants are to be issued in
Book-Entry form: Beneficial Owners and] Holders.

                                       16
<PAGE>   20

        Section 5.10    Headings. The descriptive headings of the several
Articles and Sections of this Agreement are inserted for convenience only and
shall not control or affect the meaning or construction of any of the provisions
hereof.

        Section 5.11    Severability. If any provision in this Agreement or in
any Warrant Certificate shall be invalid, illegal or unenforceable in any
jurisdiction, the validity, legality and enforceability of the remaining
provisions, or of such provisions in any other jurisdiction, shall not in any
way be affected or impaired thereby.

        Section 5.12    Counterparts. This Agreement may be executed in any
number of counterparts, each of which so executed shall be deemed to be an
original; but such counterparts shall together constitute but one and the same
instrument.

        Section 5.13    Inspection of Agreement. A copy of this Agreement shall
be available at all reasonable times at the principal corporate trust office of
the Warrant Agent and at the office of the Company for inspection by any Holder.
The Warrant Agent may require any such Holder to submit satisfactory proof of
ownership for inspection by it.

                                       17
<PAGE>   21

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

                                             XO COMMUNICATIONS, INC.

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

                                             [WARRANT AGENT]

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

                                       18
<PAGE>   22

                                    EXHIBIT A

                          [FORM OF WARRANT CERTIFICATE]

                [Form of legend if Securities with Warrants that are not
immediately detachable or Warrants that are not immediately exercisable are
offered: [PRIOR TO _______________,] THIS WARRANT CERTIFICATE [(i) CANNOT BE
TRANSFERRED OR EXCHANGED UNLESS ATTACHED TO A [TITLE OF OFFERED SECURITY] AND
(II)] CANNOT BE EXERCISED IN WHOLE OR IN PART.]

                EXERCISABLE ONLY IF COUNTERSIGNED BY THE WARRANT
                            AGENT AS PROVIDED HEREIN.

                         Warrant Certificate evidencing

                              Warrants to Purchase

                          [Title of Warrant Securities]

                              as described herein.

                             XO COMMUNICATIONS, INC.

No. ___________                                         CUSIP No. _____________

           VOID AFTER [5:00 P.M.], NEW YORK TIME, ON [_______ __, ___]

                This certifies that [________________________] or registered
assigns is the registered holder of [Insert number initially issued] warrants to
purchase certain securities (the "Warrants"). Each Warrant entitles the holder
thereof, subject to the provisions contained herein and in the Warrant Agreement
referred to below, to purchase from XO Communications, Inc., a Delaware
corporation (the "Company"), [$_________ principal amount] [______] of the
Company's [title of Securities purchasable upon exercise of Warrants] [If
Warrants for Depositary Shares are to be offered:, each representing a [1/__th]
interest in a share of [title of securities represented by the Depositary
Shares]] (the "Warrant Securities" [If Warrants for Depositary Shares are to be
offered: , which term shall also refer, as appropriate, to such [title of
securities represented by the Depositary Shares]), [issued or to be issued under
the Indenture (as hereinafter defined)], at the Exercise Price set forth below.
The exercise price of each Warrant (the "Exercise Price") shall be [modify as
appropriate to reflect the terms of the offered Warrants].

                Subject to the terms of the Warrant Agreement, each Warrant
evidenced hereby may be exercised in whole but not in part at any time, as
specified herein, [Unless Warrants may be exercised on only one date: on any
Business Day (as defined below) occurring during the period (the "Exercise
Period") commencing on [the date of issuance thereof] [_______________ __, ____]
and ending at 5:00 P.M., New York time,] on [____________ __, ____] (the
"Expiration Date"). Each Warrant remaining unexercised after 5:00 P.M., New York
time, on

                                       19
<PAGE>   23

the Expiration Date shall become void, and all rights of the holder of this
Warrant Certificate evidencing such Warrant shall cease.

                The holder of the Warrants represented by this Warrant
Certificate may exercise any Warrant evidenced hereby by delivering, not later
than 5:00 P.M., New York time, on [Unless Warrants may be exercised on only one
date: any Business Day during the Exercise Period (the "Exercise Date")] [If
Warrants may be exercised on only one date: the Expiration Date] to [name of
Warrant Agent] (the "Warrant Agent", which term includes any successor warrant
agent under the Warrant Agreement described below) at its corporate trust
department at [___________________], (i) this Warrant Certificate [For Global
Warrant Certificate: and the Warrants to be exercised (the "Book-Entry
Warrants") free on the records of [The Depositary Trust Company] (the
"Depositary") to an account of the Warrant Agent at the Depositary designated
for such purpose in writing by the Warrant Agent to the Depositary], (ii) an
election to purchase ("Election to Purchase"), [For definitive Warrant
Certificates: properly executed by the holder hereof on the reverse of this
Warrant Certificate] [For Global Warrant Certificates: properly executed by the
institution in whose account the Warrant is recorded on the records of the
Depositary (the "Participant"), and substantially in the form included on the
reverse of hereof] and (iii) the Exercise Price for each Warrant to be exercised
in lawful money of the United States of America by certified or official bank
check or by bank wire transfer in immediately available funds. If any of (a)
this Warrant Certificate [For Global Warrant Certificates: or the Book-Entry
Warrants], (b) the Election to Purchase, or (c) the Exercise Price therefor, is
received by the Warrant Agent after 5:00 P.M., New York time, on [Unless
Warrants may be exercised on only one date: the specified Exercise Date, the
Warrants will be deemed to be received and exercised on the Business Day next
succeeding the Exercise Date. If the date specified as the Exercise Date is not
a Business Day, the Warrants will be deemed to be received and exercised on the
next succeeding day which is a Business Day. If the Warrants to be exercised are
received or deemed to be received after] the Expiration Date, the exercise
thereof will be null and void and any funds delivered to the Warrant Agent will
be returned to the holder as soon as practicable. In no event will interest
accrue on funds deposited with the Warrant Agent in respect of an exercise or
attempted exercise of Warrants. The validity of any exercise of Warrants will be
determined by the Warrant Agent in its sole discretion and such determination
will be final and binding upon the holder of the Warrants and the Company.
Neither the Warrant Agent nor the Company shall have any obligation to inform a
holder of Warrants of the invalidity of any exercise of Warrants. As used
herein, the term "Business Day" means any day which is not a Saturday or Sunday
and is not a legal holiday or a day on which banking institutions generally are
authorized or obligated by law or regulation to close in [__________].

                Warrants may be exercised only in whole numbers of Warrants.
[Unless Warrants may be exercised on only one date: If fewer than all of the
Warrants evidenced by this Warrant Certificate are exercised, a new Warrant
Certificate for the number of Warrants remaining unexercised shall be executed
by the Company and countersigned by the Warrant Agent as provided in Section 1.2
of the Warrant Agreement, and delivered to the holder of this Warrant
Certificate at the address specified on the books of the Warrant Agent or as
otherwise specified by such registered holder.]

                This Warrant Certificate is issued under and in accordance with
the Warrant Agreement, dated as of [___________ __, ____] (the "Warrant
Agreement"), between the Company and the Warrant Agent and is subject to the
terms and provisions contained in the Warrant Agreement, to all of which terms
and provisions the holder of this Warrant Certificate

                                       20
<PAGE>   24

[For Global Warrant Certificate: and the beneficial owners of the Warrants
represented by this Warrant Certificate] consent[s] by acceptance hereof. Copies
of the Warrant Agreement are on file and can be inspected at the above-mentioned
office of the Warrant Agent and at the office of the Company.

                [If the Warrant Securities are Debt Securities: The Warrant
Securities to be issued and delivered upon the exercise of the Warrants
evidenced by this Warrant Certificate will be issued under and in accordance
with the Indenture, dated as of [_________ __, ____] (the "Indenture"), between
the Company and [name of trustee], as trustee (together with any successor or
successors as such trustee, the "Trustee"), and will be subject to the terms and
provisions contained in the Warrant Securities and in the Indenture.] [If the
Warrant Securities are Preferred Stock: The Warrant Securities to be issued and
delivered upon the exercise of the Warrants evidenced by this Warrant
Certificate will be issued in accordance with the certificate of designations
and the Amended and Restated Certificate of Incorporation of the Company (the
"Certificate of Incorporation") and will be subject to the terms and provisions
contained in the certificate of designations and the Certificate of
Incorporation.] The accrual of [interest] [dividends], if any, on the Warrant
Securities issued upon the valid exercise of any Warrant will be governed by the
terms of the applicable [Indenture] [certificate of designations and the
Certificate of Incorporation] and such Warrant Securities. From and after the
issuance of such Warrant Securities, the former holder of the Warrants exercised
will be entitled to the benefits of the [Indenture] [certificate of designations
and the Certificate of Incorporation] under which such Warrant Securities are
issued and such former holder's right to receive payments of [principal of (and
premium, if any) and interest, if any, on] [dividends and any other amounts
payable in respect of] the Warrant Securities shall be governed by, and shall be
subject to, the terms and provisions of such [Indenture] [certificate of
designations and Certificate of Incorporation] and the Warrant Securities.
Copies of the [Indenture, including the form of the Warrant Securities, are on
file at the corporate trust office of the Trustee] [certificate of designations
and Certificate of Incorporation are available from the Company].

                [If the Warrant Securities are Class A Common Stock: The
Exercise Price and the number of Warrant Securities purchasable upon the
exercise of each Warrant shall be subject to adjustment upon (i) the issuance of
a stock dividend to the holders of the outstanding shares of Warrant Securities
or a combination, subdivision or reclassification of the Warrant Securities;
(ii) the issuance of rights, warrants or options to all holders of the Warrant
Securities entitling the holders thereof to purchase Warrant Securities for an
aggregate consideration per share less than the current market price per share
of the Warrant Securities; or (iii) any distribution by the Company to the
holders of the Warrant Securities of evidences of indebtedness of the Company or
of assets (excluding cash dividends or distributions payable out of consolidated
earnings and earned surplus and dividends or distributions referred to in (i)
above); provided that no such adjustment in the number of Warrant Securities
purchasable upon exercise of the Warrants will be required until cumulative
adjustments require an adjustment of at least 1% of such number. No fractional
shares will be issued upon exercise of Warrants, but the Company will pay the
cash value of any fractional shares otherwise issuable. The adjustments to be
made under this Section 2.3 shall be determined by the Warrant Agent and such
determination shall be final and binding upon the holders of the Warrants and
the Company.]

                [If Securities and Warrants are to be offered together: [If
Warrants are not immediately detachable: Prior to the Detachment Date,] The
Warrants represented by this Warrant Certificate may be exchanged or transferred
only together with the [title of Offered Security] (the "Offered Security") to
which the Warrants are attached, and only for the purpose

                                       21
<PAGE>   25

of effecting, or in conjunction with, an exchange or transfer of such Offered
Security. Additionally, [If Warrants are not immediately detachable: on or prior
to the Detachment Date,] each transfer of such Offered Security on the register
of the Offered Securities shall operate also to transfer the Warrants to which
such Offered Securities was initially attached. [If Warrants are not immediately
detachable: From and after the Detachment Date, the above provisions shall be of
no further force and effect.]] Upon due presentment for registration of transfer
or exchange of this Warrant Certificate at the corporate trust office of the
Warrant Agent, the Company shall execute, and the Warrant Agent shall
countersign and deliver, as provided in Section 1.2 of the Warrant Agreement, in
the name of the designated transferee one or more new Warrant Certificates of
any authorized denomination evidencing in the aggregate a like number of
unexercised Warrants, subject to the limitations provided in the Warrant
Agreement.

                Neither this Warrant Certificate nor the Warrants evidenced
hereby shall entitle the holder hereof or thereof to any of the rights of a
holder of the Warrant Securities, including, without limitation, [the right to
receive the payments of principal of (and premium, if any), and interest, if
any, on Debt Securities purchasable upon such exercise or to enforce any of the
covenants in the applicable Indenture] [the right to receive dividends, if any,
or payments upon the liquidation, dissolution or winding up of the Company or to
exercise voting rights, if any].

                The Warrant Agreement and this Warrant Certificate may be
amended as provided in the Warrant Agreement including, under certain
circumstances described therein, without the consent of the holder of this
Warrant Certificate or the Warrants evidenced thereby.

                THIS WARRANT CERTIFICATE AND ALL RIGHTS HEREUNDER AND UNDER THE
WARRANT AGREEMENT AND PROVISIONS HEREOF AND THEREOF SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK (WITHOUT
REFERENCE TO APPLICABLE CONFLICTS OF LAW PROVISIONS).

                This Warrant Certificate shall not be entitled to any benefit
under the Warrant Agreement or be valid or obligatory for any purpose, and no
Warrant evidenced hereby may be exercised, unless this Warrant Certificate has
been countersigned by the manual signature of the Warrant Agent.

                                       22
<PAGE>   26

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

Dated as of ________ __, ____

                                             XO COMMUNICATIONS, INC.

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

                                             [NAME OF WARRANT AGENT],
                                             as Warrant Agent

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

<PAGE>   27

                                    [REVERSE]

                      INSTRUCTIONS FOR EXERCISE OF WARRANT

                To exercise the Warrants evidenced hereby, the holder [For
Global Warrant Certificate: or Participant] must, by 5:00 P.M., New York time,
on the specified Exercise Date, deliver to the Warrant Agent at its corporate
trust department, a certified or official bank check or a wire transfer in
immediately available funds, in each case payable to the Warrant Agent at
Account No. ____, in an amount equal to the Exercise Price in full for the
Warrants exercised. In addition, the Warrant holder [For Global Warrant
Certificates: or Participant] must provide the information required below and
deliver this Warrant Certificate to the Warrant Agent at the address set forth
below [For Global Warrant Certificates: and the Book-Entry Warrants to the
Warrant Agent in its account with the Depositary designated for such purpose].
This Warrant Certificate and the Election to Purchase must be received by the
Warrant Agent by 5:00 P.M., New York time, on the specified Exercise Date.

                              ELECTION TO PURCHASE
                    TO BE EXECUTED IF WARRANT HOLDER DESIRES
                    TO EXERCISE THE WARRANTS EVIDENCED HEREBY

                The undersigned hereby irrevocably elects to exercise, on
[__________, ____] (the "Exercise Date"), [_____________] Warrants, evidenced by
this Warrant Certificate, to purchase, [$_____________ principal amount]
[_________________] of the [title of Securities purchasable upon exercise of
Warrants] [If Warrants for Depositary Shares are to be offered: , each
representing a [1/__th] interest in a share of [title of securities represented
by the Depositary Shares]] (the "Warrant Securities") of XO Communications,
Inc., a Delaware corporation (the "Company"), and represents that on or before
the Exercise Date such holder has tendered payment for such Warrant Securities
by certified or official bank check or bank wire transfer in immediately
available funds to the order of the Company c/o [Name and address of Warrant
Agent], in the amount of [$_____________] in accordance with the terms hereof.
The undersigned requests that said [principal amount of] [number of] Warrant
Securities be in fully registered form, in the authorized denominations,
registered in such names and delivered, all as specified in accordance with the
instructions set forth below.

<PAGE>   28

                [Unless Warrants may be exercised on only one date: If said
[principal amount] [number] of Warrant Securities is less than all of the
Warrant Securities purchasable hereunder, the undersigned requests that a new
Warrant Certificate evidencing the remaining balance of the Warrants evidenced
hereby be issued and delivered to the holder of the Warrant Certificate unless
otherwise specified in the instructions below.]

Dated:  ______________ __, ____

                             Name
                                 -----------------------------------------------
                                 (Please Print)

                            / / / /- / / /- / / / / /

                             (Insert Social Security or Other Identifying Number
                             of Holder)
                                        ----------------------------------------

                             Address
                                           -------------------------------------

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

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

                             Signature
                                           -------------------------------------

                This Warrant may only be exercised by presentation to the
Warrant Agent at one of the following locations:

        By hand at

        By mail at

                The method of delivery of this Warrant Certificate is at the
option and risk of the exercising holder and the delivery of this Warrant
Certificate will be deemed to be made only when actually received by the Warrant
Agent. If delivery is by mail, registered mail with return receipt requested,
properly insured, is recommended. In all cases, sufficient time should be
allowed to assure timely delivery.

                (Instructions as to form and delivery of Warrant Securities
and/or Warrant Certificates)

        Name in which Warrant Securities are to be registered if other than in
the name of the registered holder of this Warrant Certificate:
                                                              ------------------

<PAGE>   29

                Address to which Warrant Securities are to be mailed if other
than to the address of the registered holder of this Warrant Certificate as
shown on the books of the Warrant Agent:

                                           -------------------------------------
                                           (Street Address)

                                           -------------------------------------
                                           (City and State) (Zip Code)

                [Except for Global Warrant Certificate: Name in which Warrant
Certificate evidencing unexercised Warrants, if any, are to be registered if
other than in the name of the registered holder of this Warrant Certificate:

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

                Address to which certificate representing unexercised Warrants,
if any, are to be mailed if other than to the address of the registered holder
of this Warrant Certificate as shown on the books of the Warrant Agent:

                                                --------------------------------
                                                (Street Address)

                                                --------------------------------
                                                (City and State) (Zip Code)

Dated:
      ---------------------------

                                                --------------------------------
                                                Signature

<PAGE>   30

        ([Except for Global Warrant Certificate: Signature must conform in all
respects to the name of the holder as specified on the face of this Warrant
Certificate.] If Warrant Securities, or a Warrant Certificate evidencing
unexercised Warrants, are to be issued in a name other than that of the
registered holder hereof or are to be delivered to an address other than the
address of such holder as shown on the books of the Warrant Agent, the above
signature must be guaranteed by a member firm of a registered national stock
exchange, a member of the National Association of Securities Dealers, Inc., a
participant in the Security Transfer Agents Medallion Program or the Stock
Exchange Medallion Program, or by a commercial bank or trust company having an
office or correspondent in the United States.)

                                       SIGNATURE GUARANTEE

                                       Name of Firm
                                                   -----------------------------
                                       Address
                                              ----------------------------------
                                       Area Code and Number
                                                           ---------------------

                                       Authorized Signature
                                                           ---------------------

                                       Name
                                           -------------------------------------

                                       Title
                                            ------------------------------------

Dated:                  ,
        ----------------  ----

<PAGE>   31

                                   ASSIGNMENT

              (FORM OF ASSIGNMENT TO BE EXECUTED IF WARRANT HOLDER
                 DESIRES TO TRANSFER WARRANTS EVIDENCED HEREBY)
               FOR VALUE RECEIVED _________________ HEREBY SELLS,
          ASSIGNS AND TRANSFERS UNTO ________________________________

(Please print name and address
                                          --------------------------------------

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

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

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

(Please insert social)
security or other identifying number)     --------------------------------------

                The rights represented by the within Warrant Certificate and
does hereby irrevocably constitute and appoint ____________ Attorney, to
transfer said Warrant Certificate on the books of the Warrant Agent with full
power of substitution in the premises.

Dated:
       ---------------------------------

                                               ---------------------------------
                                               Signature

(Signature must conform in all respects to the name of the holder as specified
on the face of this Warrant Certificate and must bear a signature guarantee by a
member firm of a registered national securities exchange, a member of the
National Association of Securities Dealers, Inc., a participant in the Security
Transfer Agents Medallion Program or the Stock Exchange Medallion Program, or by
a commercial bank or trust company having an office or correspondent in the
United States)

                                          SIGNATURE GUARANTEE

                                          Name of Firm
                                                      --------------------------

                                          Address
                                                      --------------------------

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

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

                                          Area Code and Number
                                                              ------------------

                                          Authorized Signature
                                                              ------------------

                                          Name
                                                --------------------------------
                                          Title
                                                --------------------------------

Dated:
      ---------------------------

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