<PAGE>
 
                                                                     EXHIBIT 4.8



                            Wainoco Oil Corporation




                         9-1/8% Senior Notes due 2006,
                             Series A and Series B






                                   INDENTURE

                         Dated as of February 9, 1998








                             CHASE BANK OF TEXAS,
                             NATIONAL ASSOCIATION

                                    Trustee
<PAGE>
 
                      CROSS-REFERENCE TABLE*

Trust Indenture
   Act Section                                Indenture Section  

310(a)(1). . . . . . . . . . . . . . . . . . . . . . . . . . 7.10
  (a)(2) . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10
  (a)(3) . . . . . . . . . . . . . . . . . . . . . . . . . .  N/A
  (a)(4) . . . . . . . . . . . . . . . . . . . . . . . . . .  N/A
  (a)(5) . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10
  (b). . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10
  (c). . . . . . . . . . . . . . . . . . . . . . . . . . . .  N/A
311(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11
  (b). . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11
  (c). . . . . . . . . . . . . . . . . . . . . . . . . . . .  N/A
312(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.05
  (b). . . . . . . . . . . . . . . . . . . . . . . . . . . .11.03
  (c). . . . . . . . . . . . . . . . . . . . . . . . . . . .11.03
313(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.06
  (b)(1) . . . . . . . . . . . . . . . . . . . . . . . . . . 7.06
  (b)(2) . . . . . . . . . . . . . . . . . . . . . . . 7.06, 7.07
  (c). . . . . . . . . . . . . . . . . . . . . . . . .7.06, 11.02
  (d). . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.06
314(a) . . . . . . . . . . . . . . . . . . . . . . . .4.03, 11.02
  (b). . . . . . . . . . . . . . . . . . . . . . . . . . . . .N/A
  (c)(1) . . . . . . . . . . . . . . . . . . . . . . . . . .11.04
  (c)(2) . . . . . . . . . . . . . . . . . . . . . . . . . .11.04
  (c)(3) . . . . . . . . . . . . . . . . . . . . . . . . . . .N/A
  (d). . . . . . . . . . . . . . . . . . . . . . . . . . . . .N/A
  (e). . . . . . . . . . . . . . . . . . . . . . . . . . . .11.05
  (f). . . . . . . . . . . . . . . . . . . . . . . . . . . . .N/A
315(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.01
  (b). . . . . . . . . . . . . . . . . . . . . . . . .7.05, 11.02
  (c)  . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.01
  (d). . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.01
  (e). . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.11
316(a)(last sentence). . . . . . . . . . . . . . . . . . . . 2.09
  (a)(1)(A). . . . . . . . . . . . . . . . . . . . . . . . . 6.05
  (a)(1)(B). . . . . . . . . . . . . . . . . . . . . . . . . 6.04
  (a)(2) . . . . . . . . . . . . . . . . . . . . . . . . . .  N/A
  (b). . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.07
  (c). . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.12
317(a)(1). . . . . . . . . . . . . . . . . . . . . . . . . . 6.08
  (a)(2) . . . . . . . . . . . . . . . . . . . . . . . . . . 6.09
  (b). . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.04
318(a) . . . . . . . . . . . . . . . . . . . . . . . . . . .11.01
  (b). . . . . . . . . . . . . . . . . . . . . . . . . . . . .N/A
  (c). . . . . . . . . . . . . . . . . . . . . . . . . . . .11.01

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

N/A means not applicable.
*This Cross-Reference Table is not part of the Indenture.   
<PAGE>
 
                               TABLE OF CONTENTS


                                                             Page

ARTICLE 1
         DEFINITIONS AND INCORPORATION BY REFERENCE

         Section 1.01.  Definitions. . . . . . . . . . . . . . .1
         Section 1.02.  Other Definitions. . . . . . . . . . . 18
         Section 1.03.  Incorporation by Reference of
                        Trust Indenture Act. . . . . . . . . . 19
         Section 1.04.  Rules of Construction. . . . . . . . . 19

ARTICLE 2
         THE NOTES

         Section 2.01.  Form and Dating. . . . . . . . . . . . 19
         Section 2.02.  Execution and Authentication . . . . . 21
         Section 2.03.  Registrar and Paying Agent . . . . . . 22
         Section 2.04.  Paying Agent to Hold Money in Trust. . 22
         Section 2.05.  Holder Lists . . . . . . . . . . . . . 22
         Section 2.06.  Transfer and Exchange. . . . . . . . . 23
         Section 2.07.  Replacement Notes. . . . . . . . . . . 30
         Section 2.08.  Outstanding Notes. . . . . . . . . . . 31
         Section 2.09.  Treasury Notes . . . . . . . . . . . . 31
         Section 2.10.  Temporary Notes. . . . . . . . . . . . 31
         Section 2.11.  Cancellation . . . . . . . . . . . . . 32
         Section 2.12.  Defaulted Interest . . . . . . . . . . 32

ARTICLE 3
         REDEMPTION AND PREPAYMENT

         Section 3.01.  Notices to Trustee . . . . . . . . . . 32
         Section 3.02.  Selection of Notes to Be Redeemed. . . 32
         Section 3.03.  Notice of Redemption . . . . . . . . . 33
         Section 3.04.  Effect of Notice of Redemption . . . . 34
         Section 3.05.  Deposit of Redemption Price. . . . . . 34
         Section 3.06.  Notes Redeemed in Part . . . . . . . . 34
         Section 3.07.  Optional Redemption. . . . . . . . . . 35
         Section 3.08.  Mandatory Redemption . . . . . . . . . 35
         Section 3.09.  Offer to Purchase by Application
                        of Excess Proceeds . . . . . . . . . . 35

ARTICLE 4
         COVENANTS

         Section 4.01.  Payment of Notes . . . . . . . . . . . 37
         Section 4.02.  Maintenance of Office or Agency. . . . 38

                                    - i -
<PAGE>
 
         Section 4.03.  Reports. . . . . . . . . . . . . . . . 38
         Section 4.04.  Compliance Certificate . . . . . . . . 38
         Section 4.05.  Taxes. . . . . . . . . . . . . . . . . 39
         Section 4.06.  Stay, Extension and Usury Laws . . . . 39
         Section 4.07.  Restricted Payments. . . . . . . . . . 40
         Section 4.08.  Dividend and Other Payment
                        Restrictions Affecting Subsidiaries. . 42
         Section 4.09.  Incurrence of Indebtedness and
                        Issuance of Disqualified Stock . . . . 43
         Section 4.10.  Asset Sales. . . . . . . . . . . . . . 43
         Section 4.11.  Transactions with Affiliates . . . . . 44
         Section 4.12.  Liens. . . . . . . . . . . . . . . . . 45
         Section 4.13.  Future Subsidiary Guarantees . . . . . 45
         Section 4.14.  Corporate Existence. . . . . . . . . . 45
         Section 4.15.  Offer to Repurchase Upon Change
                        of Control . . . . . . . . . . . . . . 46
         Section 4.16.  Issuances and Sales of Capital Stock
                        of Wholly Owned Restricted
                        Subsidiaries . . . . . . . . . . . . . 47
         Section 4.17.  Sale-and-leaseback Transactions. . . . 47
         Section 4.18.  No Inducements . . . . . . . . . . . . 47
         Section 4.19.  Line of Business . . . . . . . . . . . 48

ARTICLE 5
         SUCCESSORS

         Section 5.01.  Merger, Consolidation, or Sale
                        of Assets. . . . . . . . . . . . . . . 48
         Section 5.02.  Successor Corporation Substituted. . . 49

ARTICLE 6
         DEFAULTS AND REMEDIES

         Section 6.01.  Events of Default. . . . . . . . . . . 49
         Section 6.02.  Acceleration . . . . . . . . . . . . . 51
         Section 6.03.  Other Remedies . . . . . . . . . . . . 51
         Section 6.04.  Waiver of Past Defaults. . . . . . . . 51
         Section 6.05.  Control by Majority. . . . . . . . . . 52
         Section 6.06.  Limitation on Suits. . . . . . . . . . 52
         Section 6.07.  Rights of Holders of Notes to
                        Receive Payment. . . . . . . . . . . . 52
         Section 6.08.  Collection Suit by Trustee . . . . . . 52
         Section 6.09.  Trustee May File Proofs of Claim . . . 53
         Section 6.10.  Priorities . . . . . . . . . . . . . . 53
         Section 6.11.  Undertaking for Costs. . . . . . . . . 54

ARTICLE 7
         TRUSTEE

         Section 7.01.  Duties of Trustee. . . . . . . . . . . 54
         Section 7.02.  Rights of Trustee. . . . . . . . . . . 55
         Section 7.03.  Individual Rights of Trustee . . . . . 56

                                    - ii -
<PAGE>
 
         Section 7.04.  Trustee's Disclaimer . . . . . . . . . 56
         Section 7.05.  Notice of Defaults . . . . . . . . . . 56
         Section 7.06.  Reports by Trustee to Holders of
                        the Notes. . . . . . . . . . . . . . . 56
         Section 7.07.  Compensation and Indemnity . . . . . . 57
         Section 7.08.  Replacement of Trustee . . . . . . . . 57
         Section 7.09.  Successor Trustee by Merger, etc . . . 58
         Section 7.10.  Eligibility; Disqualification. . . . . 59
         Section 7.11.  Preferential Collection of Claims
                        Against Company. . . . . . . . . . . . 59

ARTICLE 8
         LEGAL DEFEASANCE AND COVENANT DEFEASANCE

         Section 8.01.  Option to Effect Legal Defeasance or
                        Covenant Defeasance. . . . . . . . . . 59
         Section 8.02.  Legal Defeasance and Discharge . . . . 59
         Section 8.03.  Covenant Defeasance. . . . . . . . . . 60
         Section 8.04.  Conditions to Legal or Covenant
                        Defeasance . . . . . . . . . . . . . . 60
         Section 8.05.  Deposited Money and Government
                        Securities to be Held in Trust;
                        Other Miscellaneous Provisions . . . . 61
         Section 8.06.  Repayment to Company . . . . . . . . . 62
         Section 8.07.  Reinstatement. . . . . . . . . . . . . 62

ARTICLE 9
         AMENDMENT, SUPPLEMENT AND WAIVER

         Section 9.01.  Without Consent of Holders of Notes. . 63
         Section 9.02.  With Consent of Holders of Notes . . . 63
         Section 9.03.  Compliance with Trust Indenture Act. . 65
         Section 9.04.  Revocation and Effect of Consents. . . 65
         Section 9.05.  Notation on or Exchange of Notes . . . 65
         Section 9.06.  Trustee to Sign Amendments, etc. . . . 65

ARTICLE 10
         GUARANTEES OF NOTES

         Section 10.01. Subsidiary Guarantees. . . . . . . . . 66
         Section 10.02. Execution and Delivery of Subsidiary
                        Guarantee. . . . . . . . . . . . . . . 67
         Section 10.03. Guarantors May Consolidate, etc.,
                        on Certain Terms . . . . . . . . . . . 67
         Section 10.04. Releases Following Sale of Assets. . . 68
         Section 10.05. Releases Following Designation as
                        an Unrestricted Subsidiary . . . . . . 69
         Section 10.06. Limitation on Guarantor Liability. . . 69
         Section 10.07. "Trustee" to Include Paying Agent. . . 69

ARTICLE 11
         MISCELLANEOUS

         Section 11.01. Trust Indenture Act Controls . . . . . 69

                                    - iii -
<PAGE>
 
         Section 11.02. Notices. . . . . . . . . . . . . . . . 69
         Section 11.03. Communication by Holders of Notes
                        with Other Holders of Notes. . . . . . 72
         Section 11.04. Certificate and Opinion as to
                        Conditions Precedent. . . . . . . . . .72
         Section 11.05. Statements Required in Certificate
                        or Opinion . . . . . . . . . . . . . . 72
         Section 11.06. Rules by Trustee and Agents. . . . . . 72
         Section 11.07. No Personal Liability of Directors,
                        Officers, Employees and Stockholders . 73
         Section 11.08. Governing Law. . . . . . . . . . . . . 73
         Section 11.09. No Adverse Interpretation of Other
                        Agreements . . . . . . . . . . . . . . 73
         Section 11.10. Successors . . . . . . . . . . . . . . 73
         Section 11.11. Severability . . . . . . . . . . . . . 73
         Section 11.12. Counterpart Originals. . . . . . . . . 73
         Section 11.13. Table of Contents, Headings, etc . . . 73


                             EXHIBITS

EXHIBIT A-1   Form of Note . . . . . . . . . . . . . . . .  A-1-1
EXHIBIT A-2   Form Regulation S Temporary Global Note. . .  A-2-1
EXHIBIT B-1   Certificate of Transferor from 144A Global
              Note to Regulation S Global Note . . . . . .  B-1-1
EXHIBIT B-2   Certificate of Transferor from Regulation S
              Global Note to 144A Global Note . . . . . .   B-2-1
EXHIBIT B-3   Certificate of Transferor of Definitive Notes B-3-1
EXHIBIT B-4   Certificate of Transferor from Global Note to
              Definitive  Note . . . . . . . . . . . . . .  B-4-1
EXHIBIT C Certificate of Institutional Accredited Investor    C-1
EXHIBIT D Form of Subsidiary Guarantee . . . . . . . . . .    D-1
EXHIBIT E Form of Supplemental Indenture . . . . . . . . .    E-1

                                    - iv -
<PAGE>
 
   This Indenture, dated as of February 9, 1998 is between Wainoco Oil
Corporation, a Wyoming corporation (the "Company"), and Chase Bank of Texas,
National Association, a national banking association, as trustee (the
"Trustee").

    The Company and the Trustee agree as follows for the benefit of each other
and for the equal and ratable benefit of the Holders of the 9-1/8% Senior Notes
due 2006, Series A (the "Series A Notes") and the 9-1/8% Senior Notes due 2006,
Series B (the "Series B Notes" and, together with the Series A Notes, the
"Notes"), without preference of one series of Notes over the other:

                                   ARTICLE 1
                         DEFINITIONS AND INCORPORATION
                                 BY REFERENCE

Section 1.01. Definitions.

    "144A Global Note" means a permanent global senior note that contains the
paragraph referred to in footnote 1 and the additional schedule referred to in
footnote 3 to the form of the Note attached hereto as Exhibit A-1, and that is
deposited with the Note Custodian and registered in the name of the Depository
or its nominee, representing a series of Notes sold in reliance on Rule 144A or
another exemption from the registration requirements of the Securities Act,
other than Regulation S.

    "Adjusted Net Assets" of a Guarantor at any date shall mean the amount by
which the fair value of the properties and assets of such Guarantor exceeds the
total amount of liabilities, including, without limitation, contingent
liabilities (after giving effect to all other fixed and contingent liabilities
incurred or assumed on such date), but excluding liabilities under its
Subsidiary Guarantee, of such Guarantor at such date.

    "Affiliate" of any specified Person means an "affiliate" of such Person, as
such term is defined for purposes of Rule 144 under the Securities Act.

    "Agent" means any Registrar, Paying Agent or co-registrar.

    "Applicable Procedures" means, with respect to any transfer or exchange of
beneficial interests in a Global Note, the rules and procedures of the
Depository that apply to such transfer and exchange.

    "Asset Sale" means (a) the sale, lease, conveyance or other disposition (a
"disposition") of any assets or rights (including, without limitation, by way of
a sale and leaseback), excluding dispositions in the ordinary course of business
(provided that the disposition of all or substantially all of the assets of the
Company and its Subsidiaries taken as a whole will be governed by Sections 4.15
and/or 5.01 of this Indenture and not by the provisions of Section 4.10 hereof),
(b) the issue or sale by the Company or any of its Restricted Subsidiaries of
Equity Interests of any of the Company's Subsidiaries, and (c) any Event of
Loss, whether in the case of clause (a), (b) or (c), in a single transaction or
a series of related transactions, provided that such transaction or series of
transactions (i) has a fair market value in excess of $1.0 million or (ii)
results in the payment of net proceeds in

                                    - 1 -
<PAGE>
 
excess of $1.0 million.  Notwithstanding the foregoing, the following
transactions will be deemed not to be Asset Sales:  (A) a disposition of
obsolete or excess equipment or other assets; (B) a disposition of assets by the
Company to a Wholly Owned Restricted Subsidiary or by a Wholly Owned Restricted
Subsidiary to the Company or to another Wholly Owned Restricted Subsidiary; (C)
a disposition of Equity Interests by a Wholly Owned Restricted Subsidiary to the
Company or to another Wholly Owned Restricted Subsidiary; (D) a Permitted
Investment or Restricted Payment that is permitted by this Indenture; (E)  any
lease of any equipment or other assets entered into in the ordinary course of
business and with respect to which the Company or any Restricted Subsidiary
thereof is the lessor, except any such lease that provides for the acquisition
of such assets by the lessee during or at the end of the term thereof  for an
amount that is less than the fair market value thereof at the time the right to
acquire such assets occurs; (F) a disposition of assets by the Company or any of
its Restricted Subsidiaries to a Person that is an Affiliate of the Company or
such Restricted Subsidiary and is engaged in the business of providing marine
support vessels and related services to the oil and gas industry (or a business
that is reasonably complementary or related thereto as determined in good faith
by the Board of Directors), which Person is an Affiliate solely because the
Company or such Restricted Subsidiary has an Investment in such Person, provided
that such transaction complies with Section 4.11 hereof; and (G) any trade or
exchange by the Company or any Restricted Subsidiary of any inventory or
hydrocarbon or other products (including crude oil and refined products) or
similar products owned or held by another Person, provided that the fair market
value of the properties traded or exchanged by the Company or such Restricted
Subsidiary is reasonably equivalent to the fair market value of the properties
to be received by the Company or such Restricted Subsidiary.  The fair market
value of any non-cash proceeds of a disposition of assets and of any assets
referred to in the foregoing clause (G) of this definition shall be determined
in the manner contemplated in the definition of the term "fair market value,"
and, in the event the fair market value so determined exceeds $2.0 million, the
results of such determination shall be set forth in an Officers' Certificate
delivered to the Trustee.

    "Attributable Indebtedness"  in respect of a sale-and-leaseback transaction
means, at the time of determination, the present value (discounted at the rate
of interest implicit in such transaction, determined in accordance with GAAP) of
the obligation of the lessee for net rental payments during the remaining term
of the lease included in such sale-and-lease-back transaction (including any
period for which such lease has been extended or may, at the option of the
lessor, be extended).  As used in the preceding sentence, the "net rental
payments" under any lease for any such period  shall mean the sum of rental and
other payments required to be paid with respect to such period by the lessee
thereunder, excluding any amounts required to be paid by such lessee on account
of maintenance and repairs, insurance, taxes, assessments, water rates or
similar charges.  In the case of any lease that is terminable by the lessee upon
payment of penalty, such net rental payment shall also include the amount of
such penalty, but no rent shall be considered as required to be paid under such
lease subsequent to the first date upon which it may be so terminated.

    "Bankruptcy Law" means Title 11, United States Code, or any similar federal
or state law for the relief of debtors.

    "Board of Directors" means the board of directors of the Company or any
committee thereof that is authorized to act on behalf of such board.

                                    - 2 -
<PAGE>
 
    "Business Day" means any day other than a Legal Holiday.

    "Capital Lease Obligation" means, at the time any determination thereof is
to be made, the amount of the liability in respect of a capital lease that would
at such time be required to be capitalized on a balance sheet in accordance with
GAAP.

    "Capital Stock" means (a) in the case of a corporation, corporate stock, (b)
in the case of an association or business entity, any and all shares, interests,
participations, rights or other equivalents (however designated) of corporate
stock, (c) in the case of a partnership or limited liability company,
partnership or membership interests (whether general or limited) and (d) any
other interest or participation that confers on a Person the right to receive a
share of the profits and losses of, or distributions of assets of, the issuing
Person.

    "Cash Equivalents" means (a) United States dollars or up to $2.0 million of
Canadian dollars, (b) securities issued or directly and fully guaranteed or
insured by the United States government or any agency or instrumentality thereof
having maturities of not more than six months from the date of acquisition, (c)
certificates of deposit and Eurodollar time deposits with maturities of six
months or less from the date of acquisition, bankers' acceptances with
maturities not exceeding six months and overnight bank deposits, in each case
with any commercial bank organized under the laws of any country that is a
member of the Organization for Economic Cooperation and Development having
capital and surplus in excess of $500 million, (d) repurchase obligations with a
term of not more than seven days for underlying securities of the types
described in clauses (b) and (c) above entered into with any financial
institution meeting the qualifications specified in clause (c) above, (e)
commercial paper having the highest rating obtainable from Moody's Investors
Service, Inc. or Standard  & Poor's Rating Service and in each case maturing
within 180 days after the date of acquisition, (f) deposits available for
withdrawal on demand with any commercial bank not meeting the qualifications
specified in clause (c) above, provided all such deposits do not exceed $2.0
million in the aggregate at any one time,  and (g) money market mutual funds
substantially all of the assets of which are of the type described in the
foregoing clauses (a) through (e).

    "Cedel" means Cedel bank, societe anonyme.

    "Change of Control" means the occurrence of any of the following:  (a) the
sale, lease, transfer, conveyance or other disposition (other than by way of
merger or consolidation), in one or a series of related transactions, of all or
substantially all of the assets of the Company and its Subsidiaries, taken as a
whole, (b) the adoption of a plan relating to the liquidation or dissolution of
the Company, (c) the consummation of any transaction (including, without
limitation, any merger or consolidation) the result of which is that any
"person" (as such term is used in Section 13(d)(3) of the Exchange Act) becomes
the "beneficial owner" (as such term is defined in Rule 13d-3 and Rule 13d-5
under the Exchange Act), directly or indirectly through one or more
intermediaries, of more than 50% of the voting power of the outstanding voting
stock of the Company or (d) the first day on which more than a majority of the
members of the Board of Directors are not Continuing Directors; provided,
however, that a transaction in which the Company becomes a Subsidiary of another
Person (other than a Person that is an individual) shall not constitute a Change
of Control if (i) the stockholders of the Company immediately prior to such
transaction "beneficially own" (as such term is defined in Rule 13d-3 and Rule
13d-5 under the Exchange Act), directly or indirectly

                                    - 3 -
<PAGE>
 
through one or more intermediaries, at least a majority of the voting power of
the outstanding voting stock of the Company immediately following the
consummation of such transaction and (ii) immediately following the consummation
of such transaction, no "person" (as such term is defined above), other than
such other Person (but including the holders of the Equity Interests of such
other Person), "beneficially owns" (as such term is defined above), directly or
indirectly through one or more intermediaries, more than 50% of the voting power
of the outstanding voting stock of the Company.

    "Common Stock" means the common stock of the Company, no par value per
    share.

    "Consolidated Cash Flow" means, with respect to any Person for any period,
the Consolidated Net Income of such Person for such period plus, to the extent
deducted or excluded in calculating Consolidated Net Income for such period, (a)
an amount equal to any extraordinary loss plus any net loss realized in
connection with an Asset Sale, (b) provision for taxes based on income or
profits of such Person and its Restricted Subsidiaries, (c) Consolidated
Interest Expense of such Person and its Restricted Subsidiaries, and (d)
depreciation and amortization (including amortization of goodwill and other
intangibles but excluding amortization of prepaid cash expenses that were paid
in a prior period) of such Person and its Restricted Subsidiaries, in each case,
on a consolidated basis and determined in accordance with GAAP.

    "Consolidated Interest Coverage Ratio" means with respect to any Person for
any period, the ratio of the Consolidated Cash Flow of such Person for such
period to the Consolidated Interest Expense of such Person for such period;
provided, however, that the Consolidated Interest Coverage Ratio shall be
calculated giving pro forma effect to each of the following transactions as if
each such transaction had occurred at the beginning of the applicable
four-quarter reference period:  (a) any incurrence, assumption, guarantee or
redemption by the Company or any of its Restricted Subsidiaries of any
Indebtedness (other than revolving credit borrowings) subsequent to the
commencement of the period for which the Consolidated Interest Coverage Ratio is
being calculated but prior to the date on which the event for which the
calculation of the Consolidated Interest Coverage Ratio is made (the
"Calculation Date"); (b) any acquisition that has been made by the Company or
any of its Restricted Subsidiaries, or approved and expected to be consummated
within 30 days of the Calculation Date, including, in each case, through a
merger or consolidation, and including any related financing transactions,
during the four-quarter reference period or subsequent to such reference period
and on or prior to the Calculation Date (in which case Consolidated Cash Flow
for such reference period shall be calculated without giving effect to clause
(c) of the proviso set forth in the definition of Consolidated Net Income); and
(c) any other transaction that may be given pro forma effect in accordance with
Article 11 of Regulation S-X as in effect from time to time; provided, further,
however, that (i) the Consolidated Cash Flow attributable to discontinued
operations, as determined in accordance with GAAP, and operations or businesses
disposed of prior to the Calculation Date, shall be excluded and (ii) the
Consolidated Interest Expense attributable to discontinued operations, as
determined in accordance with GAAP, and operations or businesses disposed of
prior to the Calculation Date, shall be excluded, but only to the extent that
the obligations giving rise to such Consolidated Interest Expense will not be
obligations of the referent Person or any of its Restricted Subsidiaries
following the Calculation Date.

                                    - 4 -
<PAGE>
 
    "Consolidated Interest Expense" means, with respect to any Person for any
period, the sum, without duplication, of (a) the consolidated interest expense
of such Person and its Restricted Subsidiaries for such period, whether paid or
accrued (including, without limitation, amortization of original issue discount,
non-cash interest payments, the interest component of any deferred payment
obligations, the interest component of all payments associated with Capital
Lease Obligations, commissions, discounts and other fees and charges incurred in
respect of letter of credit or bankers' acceptance financings, and net payments
(if any) pursuant to Hedging Obligations but excluding amortization of debt
issuance costs) and (b) the consolidated interest expense of such Person and its
Restricted Subsidiaries that was capitalized during such period, in each case
determined on a consolidated basis in accordance with GAAP.

    "Consolidated Net Income" means, with respect to any Person for any period,
the aggregate of the Net Income of such Person and its Restricted Subsidiaries
for such period, on a consolidated basis, determined in accordance with GAAP,
provided that (a) the Net Income (but not loss) of any Person that is not a
Restricted Subsidiary or that is accounted for by the equity method of
accounting shall be included only to the extent of the amount of dividends or
distributions paid in cash to the referent Person or a Restricted Subsidiary
thereof, (b) the Net Income of any Restricted Subsidiary shall be excluded to
the extent that the declaration or payment of dividends or similar distributions
by that Restricted Subsidiary of that Net Income is not at the date of
determination permitted without any prior governmental approval (that has not
been obtained) or, directly or indirectly, by operation of the terms of its
charter or any agreement, instrument, judgment, decree, order, statute, rule or
governmental regulation applicable to that Subsidiary or its stockholders, (c)
the Net Income of any Person acquired in a pooling of interests transaction for
any period prior to the date of such acquisition shall be excluded and (d) the
cumulative effect of a change in accounting principles shall be excluded.

    "Consolidated Net Tangible Assets" means, with respect to any Person as of
any date, the sum of the amounts that would appear on a consolidated balance
sheet of such Person and its consolidated Restricted Subsidiaries as the total
assets of such Person and its consolidated Restricted Subsidiaries, determined
on a consolidated basis in accordance with GAAP and after deducting therefrom,
(a) to the extent otherwise included, unamortized debt discount and expenses and
other unamortized deferred charges, goodwill, patents, trademarks, service
marks, trade names, copyrights, licenses, organization or development expenses
and other intangible items and (b) the aggregate amount of liabilities of the
Company and its Restricted Subsidiaries which may be properly classified as
current liabilities (including tax accrued as estimated), determined on a
consolidated basis in accordance with GAAP.

    "Consolidated Net Worth" means, with respect to any Person as of any date,
the sum of (a) the consolidated equity of the common stockholders of such Person
and its consolidated Restricted Subsidiaries as of such date plus (b) the
respective amounts reported on such Person's balance sheet as of such date with
respect to any series of preferred stock (other than Disqualified Stock) that by
its terms is not entitled to the payment of dividends unless such dividends may
be declared and paid only out of net earnings in respect of the year of such
declaration and payment, but only to the extent of any cash received by such
Person upon issuance of such preferred stock, less (i) all write-ups (other than
write-ups resulting from foreign currency translations and write-ups of tangible
assets of a going concern business made within 12 months after the acquisition
of such

                                    - 5 -
<PAGE>
 
business) subsequent to the Issue Date in the book value of any asset owned by
such Person or a consolidated Restricted Subsidiary of such Person, (ii) all
investments as of such date in unconsolidated Subsidiaries and in Persons that
are not Restricted Subsidiaries and (iii) all unamortized debt discount and
expense and unamortized deferred charges as of such date, in each case
determined in accordance with GAAP.

    "Continuing Directors" means, as of any date of determination, any member of
the Board of Directors who (a) was a member of the Board of Directors on the
Issue Date or (b) was nominated for election to the Board of Directors with the
approval of, or whose election to the Board of Directors was ratified by, at
least two-thirds of the Continuing Directors who were members of the Board of
Directors at the time of such nomination or election.

    "Corporate Trust Office of the Trustee" shall be at the address of the
Trustee specified in Section 11.02 hereof or such other address as to which the
Trustee may give notice to the Company.

    "Credit Facility" means that certain Amended and Restated Revolving Credit
and Letter of Credit Agreement dated June 30, 1997 among Frontier Oil and
Refining Company, certain banks and Union Bank of California, N.A., including
any related notes, guarantees, collateral documents, instruments and agreements
executed in connection therewith, in each case as amended, restated, modified,
supplemented, extended, renewed, replaced, refinanced or restructured from time
to time, whether by the same or any other agent or agents, lender or group of
lenders, whether represented by one or more agreements and whether one or more
Subsidiaries are added or removed as borrowers or guarantors thereunder or as
parties thereto.

    "Custodian" means any receiver, trustee, assignee, liquidator, sequestrator
or similar official under any Bankruptcy Law.

    "Default" means any event that is or with the passage of time or the giving
of notice or both would be an Event of Default.

    "Definitive Notes" means Notes that are in the form of Exhibit A-1 attached
hereto (but without including the text referred to in footnotes 1 and 3
thereto).

    "Depository" means, with respect to the Notes issuable or issued in whole or
in part in global form, the Person specified in Section 2.03 hereof as the
Depository with respect to the Notes, until a successor shall have been
appointed and become such pursuant to the applicable provision of this
Indenture, and, thereafter, "Depository" shall mean or include such successor.

    "Disqualified Stock" means any Capital Stock that, by its terms (or by the
terms of any security into which it is convertible or for which it is
exchangeable), or upon the happening of any event, matures (excluding any
maturity as a result of an optional redemption by the issuer thereof) or is
mandatorily redeemable, pursuant to a sinking fund obligation or otherwise, or
redeemable at the option of the holder thereof, in whole or in part, on or prior
to the date that is 91 days after the date on which the Notes mature or are
redeemed or retired in full; provided, however, that any Capital Stock that
would constitute Disqualified Stock solely because the holders thereof (or of
any security into which it is convertible or for which it is exchangeable) have
the right to require the

                                    - 6 -
<PAGE>
 
issuer to repurchase such Capital Stock (or such security into which it is
convertible or for which it is exchangeable) upon the occurrence of any of the
events constituting an Asset Sale or a Change of Control shall not constitute
Disqualified Stock if such Capital Stock (and all such securities into which it
is convertible or for which it is exchangeable) provides that the issuer thereof
will not repurchase or redeem any such Capital Stock (or any such security into
which it is convertible or for which it is exchangeable) pursuant to such
provisions prior to compliance by the Company with Section 4.10 or 4.15 of this
Indenture, as the case may be.

    "Equity Interests" means Capital Stock and all warrants, options or other
rights to acquire Capital Stock (but excluding any debt security that is
convertible into, or exchangeable for, Capital Stock).

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

    "Event of Loss" means, with respect to any property or asset of the Company
or any Restricted Subsidiary, (a) any damage to such property or asset that
results in an insurance settlement with respect thereto on the basis of a total
loss or a constructive or compromised total loss or (b) the confiscation,
condemnation or requisition of title to such property or asset by any government
or instrumentality or agency thereof.  An Event of Loss shall be deemed to occur
as of the date of the insurance settlement, confiscation, condemnation or
requisition of title, as applicable.

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

    "Exchange Offer" means the offer that may be made by the Company pursuant to
a Registration Rights Agreement to exchange Series B Notes for Series A Notes.

    "Existing Indebtedness" means Indebtedness of the Company and its Restricted
Subsidiaries (other than Indebtedness under the Credit Facility) in existence on
the Issue Date, until such amounts are repaid.

    The term "fair market value" means, with respect to any asset or Investment,
the fair market value of such asset or Investment at the time of the event
requiring such determination, as determined in good faith by the Board of
Directors of the Company, or, with respect to any asset or Investment in excess
of $10.0 million (other than cash or Cash Equivalents), as determined by a
reputable appraisal firm that is, in the judgment of such Board of Directors,
qualified to perform the task for which such firm has been engaged and
independent with respect to the Company.

    "GAAP" means generally accepted accounting principles set forth in the
opinions and pronouncements of the Accounting Principles Board of the American
Institute of Certified Public Accountants and statements and pronouncements of
the Financial Accounting Standards Board or in such other statements by such
other entity as have been approved by a significant segment of the accounting
profession, which are in effect from time to time.

    "Global Note" means, individually and collectively, the Regulation S
Temporary Global Note, the Regulation S Permanent Global Note and the 144A
Global Note.

                                    - 7 -
<PAGE>
 
    "Government Securities" means direct obligations of, or obligations
guaranteed by, the United States of America for the payment of which guarantee
or obligations the full faith and credit of the United States is pledged.

    "Guarantor" means any Restricted Subsidiary of the Company that executes a
Subsidiary Guarantee in accordance with Sections 4.13 and 10.02 hereof and (c)
the respective successors and assigns of such Restricted Subsidiaries, as
required under Article 10 hereof, in each case until such time as any such
Restricted Subsidiary shall be released and relieved of its obligations pursuant
to Section 10.04 or 10.05 hereof.

    "Hedging Obligations" means, with respect to any Person, the obligations of
such Person under (a) interest rate swap agreements, interest rate cap
agreements and interest rate collar agreements, but only to the extent that the
notional amounts of such agreements do not exceed 105% of the aggregate
principal amount of such Indebtedness to which such agreement relates, (b) other
agreements or arrangements designed to protect such Person against fluctuations
in interest rates, (c) any hedging agreement or other arrangement, in each case
that is designed to provide protection against fluctuations in the price of
crude oil and gasoline and other refined products (in the ordinary course of
business and not for speculative purposes) and (d) any foreign currency futures
contract, option or similar agreement or arrangement designed to protect such
Person against fluctuations in foreign currency rates, in each case to the
extent such obligations are incurred in the ordinary course of business of such
Person.

    "Holder" means a Person in whose name a Note is registered.

    "Indebtedness" means, with respect to any Person, any indebtedness of such
Person, whether or not contingent, in respect of borrowed money or evidenced by
bonds, debentures, notes or similar instruments or letters of credit (or
reimbursement agreements in respect thereof) or banker's acceptances or
representing Capital Lease Obligations or the balance deferred and unpaid of the
purchase price of any property or representing any Hedging Obligations, except
any such balance that constitutes an accrued expense or trade payable, if and to
the extent any of the foregoing indebtedness (other than letters of credit and
Hedging Obligations) would appear as a liability upon a balance sheet of such
Person prepared in accordance with GAAP. The amount of any Indebtedness
outstanding as of any date shall be (a) the accreted value thereof, in the case
of any Indebtedness that does not require current payments of interest, and (b)
the principal amount thereof, in the case of any other Indebtedness.

    "Indenture" means this Indenture, as amended or supplemented from time to
    time.

    "Indirect Participant" means a Person who holds an interest through a
    Participant.

    "Initial Purchaser" means Bear, Stearns & Co. Inc.

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

                                    - 8 -
<PAGE>
 
    "Investments" means, with respect to any Person, all investments by such
Person in other Persons (including Affiliates) in the forms of direct or
indirect loans (including guarantees by the referent Person of, and Liens on any
assets of the referent Person securing, Indebtedness or other obligations of
other Persons), advances or capital contributions (excluding commission, travel
and similar advances to officers and employees made in the ordinary course of
business), purchases or other acquisitions for consideration of Indebtedness,
Equity Interests or other securities, together with all items that are or would
be classified as investments on a balance sheet prepared in accordance with
GAAP; provided, however, that the following shall not constitute Investments:
(i) extensions of trade credit or other advances to customers on commercially
reasonable terms in accordance with normal trade practices or otherwise in the
ordinary course of business, (ii) Hedging Obligations and (iii) endorsements of
negotiable instruments and documents in the ordinary course of business.  If the
Company or any Restricted Subsidiary of the Company sells or otherwise disposes
of any Equity Interests of any direct or indirect Restricted Subsidiary of the
Company such that, after giving effect to any such sale or disposition, such
Person is no longer a Restricted Subsidiary of the Company, the Company shall be
deemed to have made an Investment on the date of any such sale or disposition
equal to the fair market value of the Equity Interests of such Restricted
Subsidiary not sold or disposed of in an amount determined as provided in the
final paragraph of the covenant described in Section 4.07 of this Indenture.

    "Issue Date" means the first date on which the Offered Notes are issued
    hereunder.

    "Legal Holiday" means a Saturday, a Sunday or a day on which banking
institutions in the City of Houston, Texas, the City of New York or at a place
of payment are authorized by law, regulation or executive order to remain
closed.  If a payment date is a Legal Holiday at a place of payment, payment may
be made at that place on the next succeeding day that is not a Legal Holiday,
and no interest shall accrue for the intervening period.

    "Lien" means, with respect to any asset, any mortgage, lien, pledge, charge,
security interest or encumbrance of any kind in respect of such asset, whether
or not filed, recorded or otherwise perfected under applicable law (including
any conditional sale or other title retention agreement, any lease in the nature
thereof, any option or other agreement to sell or give a security interest in
and any filing of or agreement to give any financing statement under the Uniform
Commercial Code (or equivalent statutes) of any jurisdiction other than a
precautionary financing statement respecting a lease not intended as a security
agreement).

    "Liquidated Damages" means all liquidated damages then owing pursuant to
Section 5 of the Registration Rights Agreement.

    "Make-Whole Amount" with respect to a Note means an amount equal to the
excess, if any, of (i) the present value of the remaining interest, premium and
principal payments due on such Note as if such Note were redeemed on February
15, 2002, computed using a discount rate equal to the Treasury Rate plus 50
basis points, over (ii) the outstanding principal amount of such Note. "Treasury
Rate" is defined as the yield to maturity at the time of the computation of
United States Treasury securities with a constant maturity (as compiled by and
published in the most recent Federal Reserve Statistical Release H.15(519),
which has become publicly available at least two Business Days prior to the date
of the redemption notice or, if such Statistical Release is no longer published,

                                    - 9 -
<PAGE>
 
any publicly available source of similar market date) most nearly equal to the
then remaining maturity of the Notes assuming redemption of the Notes on
February 15, 2002; provided, however, that if the Make-Whole Average Life of
such Note is not equal to the constant maturity of the United States Treasury
security for which a weekly average yield is given, the Treasury Rate shall be
obtained by linear interpolation (calculated to the nearest one-twelfth of a
year) from the weekly average yields of United States Treasury securities for
which such yields are given, except that if the Make-Whole Average Life of such
Notes is less than one year, the weekly average yield on actually traded United
States Treasury securities adjusted to a constant maturity of one year shall be
used.  "Make-Whole Average Life" means the number of years (calculated to the
nearest one-twelfth) between the date of redemption and February 15, 2002.

    "Make-Whole Price" with respect to a Note means the greater of (i) the sum
of the outstanding principal amount and Make-Whole Amount of such Note, and (ii)
the redemption price of such Note on February 15, 2002, determined pursuant to
the Indenture (104.563% of the principal amount).

    "Net Income" means, with respect to any Person, the net income (loss) of
such Person, determined in accordance with GAAP and before any reduction in
respect of preferred stock dividends, excluding, however, (a) any gain (but not
loss), together with any related provision for taxes on such gain (but not
loss), realized in connection with (i) any Asset Sale (including, without
limitation, dispositions pursuant to sale-and-leaseback transactions) or (ii)
the disposition of any securities by such Person or any of its Restricted
Subsidiaries or the extinguishment of any Indebtedness of such Person or any of
its Restricted Subsidiaries and (b) any extraordinary or nonrecurring gain (but
not loss), together with any related provision for taxes on such extraordinary
or nonrecurring gain (but not loss).

    "Net Proceeds" means the aggregate cash proceeds received by the Company or
any of its Restricted Subsidiaries in respect of any Asset Sale (including,
without limitation, any cash received upon the sale or other disposition of any
non-cash consideration received in any Asset Sale), net of (without duplication)
(a) the direct costs relating to such Asset Sale (including, without limitation,
legal, accounting and investment banking fees, sales commissions, recording
fees, title transfer fees, title insurance premiums, appraiser fees and costs
incurred in connection with preparing such asset for sale) and any relocation
expenses incurred as a result thereof, (b) taxes paid or estimated to be payable
as a result thereof (after taking into account any available tax credits or
deductions and any tax sharing arrangements), (c) amounts required to be applied
to the repayment of Indebtedness (other than under the Credit Facility) secured
by a Lien on the asset or assets that were the subject of such Asset Sale and
(d) any reserve established in accordance with GAAP or any amount placed in
escrow, in either case for adjustment in respect of the sale price of such asset
or assets, until such time as such reserve is reversed or such escrow
arrangement is terminated, in which case Net Proceeds shall include only the
amount of the reserve so reserved or the amount returned to the Company or its
Restricted Subsidiaries from such escrow arrangement, as the case may be.

    "Non-Recourse Debt" means Indebtedness (a) as to which neither the Company
nor any of its Restricted Subsidiaries (i) provides credit support of any kind
(including any undertaking, agreement or instrument that would constitute
Indebtedness) or is otherwise directly or indirectly liable (as a guarantor or
otherwise) or (ii) constitutes the lender, (b) no default with respect to which

                                    - 10 -
<PAGE>
 
(including any rights that the holders thereof may have to take enforcement
action against an Unrestricted Subsidiary) would permit (upon notice, lapse of
time or both) the holders of Indebtedness of the Company or any of its
Restricted Subsidiaries to declare a default on such Indebtedness or cause the
payment thereof to be accelerated or payable prior to its stated maturity and
(c) as to which the lenders have been notified in writing that they will not
have any recourse to the stock or assets of the Company or any of its Restricted
Subsidiaries, except to the extent of any Indebtedness incurred by the Company
or any of its Restricted Subsidiaries in accordance with clause (a)(i) above.

    "Note Custodian" means the Trustee, as custodian with respect to the Notes
in global form, or any successor entity thereto.

    "Obligations" means any principal, interest, penalties, fees,
indemnifications, reimbursements, damages and other liabilities payable under
the documentation governing any Indebtedness.

    "Offered Notes" has the meaning set forth in Section 2.02 hereof.

    "Officer" means, with respect to any Person, the Chairman of the Board, the
Chief Executive Officer, the President, the Chief Operating Officer, the Chief
Financial Officer, the Treasurer, any Assistant Treasurer, the Controller, the
Secretary or any Vice-President of such Person.

    "Officers' Certificate" means a certificate signed on behalf of the Company
by two Officers of the Company, one of whom must be the principal executive
officer, the principal financial officer, the treasurer or the principal
accounting officer of the Company, that meets the requirements of Section 11.05
hereof.

    "Opinion of Counsel" means an opinion from legal counsel who is reasonably
acceptable to the Trustee, that meets the requirements of Section 11.05 hereof.
The counsel may be an employee of or counsel to the Company, any Subsidiary of
the Company or the Trustee.

    "Original Notes" has the meaning set forth in Section 2.02 hereof.

    "Pari Passu Indebtedness" means, with respect to any Net Proceeds from Asset
Sales, Indebtedness of the Company and its Restricted Subsidiaries the terms of
which require the Company or such Restricted Subsidiary to apply such Net
Proceeds to offer to repurchase such Indebtedness.

    "Participant" means with respect to DTC, Euroclear or Cedel, a Person who
has an account with DTC, Euroclear or Cedel, respectively (and, with respect to
DTC, shall include Euroclear and Cedel).

                                    - 11 -
<PAGE>
 
    "Permitted Indebtedness" means:

         (a)  the incurrence by the Company or a Restricted Subsidiary of
    Indebtedness under any Working Capital Facility in an aggregate principal
    amount at any one time outstanding not to exceed the greater of (i) $50.0
    million and (ii) an amount equal to the sum of 85% of the book value of
    accounts receivable (less allowance for doubtful accounts) and 60% of the
    inventory (less applicable reserves) of the Company and its Restricted
    Subsidiaries, calculated on a consolidated basis and in accordance with
    GAAP, plus any fees, premiums, expenses (including costs of collection),
    indemnities and similar amounts payable in connection with such
    Indebtedness, and less any amounts repaid permanently in accordance with
    Section 4.10 hereof;

         (b)  the incurrence by the Company and its Restricted Subsidiaries of
    Existing Indebtedness;

         (c)  the incurrence by the Company and its Restricted Subsidiaries of
    Hedging Obligations;

         (d)  the incurrence by the Company of Indebtedness represented by the
    Offered Notes and Exchange Notes;

         (e)  the incurrence of intercompany Indebtedness between or among the
    Company and any of its Restricted Subsidiaries, provided that (i) if the
    Company or any Guarantor is the obligor on such Indebtedness, such
    Indebtedness is expressly subordinate to the payment in full of all
    obligations with respect to the Notes and (ii) (A) any subsequent issuance
    or transfer of Equity Interests that results in any such Indebtedness being
    held by a Person other than the Company or a Restricted Subsidiary of the
    Company, or (B) any sale or other transfer of any such Indebtedness to a
    Person that is neither the Company nor a Restricted Subsidiary of the
    Company, shall be deemed to constitute an incurrence of such Indebtedness by
    the Company or such Restricted Subsidiary, as the case may be;

         (f)  Indebtedness in respect of bid, performance or surety bonds issued
    for the account of the Company or any Restricted Subsidiary thereof in the
    ordinary course of business, including guarantees or obligations of the
    Company or any Restricted Subsidiary thereof with respect to letters of
    credit supporting such bid, performance or surety obligations (in each case
    other than for an obligation for money borrowed);

         (g)  the incurrence by the Company or any of its Restricted
    Subsidiaries of Permitted Refinancing Debt in exchange for, or the net
    proceeds of which are used to extend, refinance, renew, replace, defease or
    refund Indebtedness that was permitted by the Indenture to be incurred
    (other than pursuant to clause (a) or (e) of this definition);

         (h)  incurrence by any Subsidiary of the Company of a Subsidiary
     Guarantee;

         (i)  incurrence of Non-Recourse Debt; or

                                    - 12 -
<PAGE>
 
         (j)  incurrence by the Company or any Restricted Subsidiary of any
    additional Indebtedness not to exceed $5.0 million at any time outstanding.

    In the event that the incurrence of any Indebtedness would be permitted
under Section 4.09 hereof or one or more of the provisions of this definition,
the Company may designate (in the form of an Officers' Certificate delivered to
the Trustee) the particular provision of the Indenture pursuant to which it is
incurring such Indebtedness.

    "Permitted Investments" means (a) any Investment in the Company or in a
Restricted Subsidiary of the Company, (b) any Investment in Cash Equivalents,
(c) any Investment by the Company or any Restricted Subsidiary of the Company in
a Person if as a result of such Investment (i) such Person becomes a Restricted
Subsidiary of the Company or (ii) such Person is merged, consolidated or
amalgamated with or into, or transfers or conveys all or substantially all of
its assets to, or is liquidated into, the Company or a Restricted Subsidiary of
the Company, (d) any Investment made as a result of the receipt of non-cash
consideration from (i) an Asset Sale that was made pursuant to and in compliance
with Section 4.10 hereof or (ii) a disposition of assets that does not
constitute an Asset Sale, (e) acquisition of assets solely in exchange for the
issuance of Equity Interests (other than Disqualified Stock) of the Company and
(f) Investments in a Person engaged in the Principal Business, provided that the
aggregate amount of such Investments pursuant to this clause (f) in Persons that
are not Restricted Subsidiaries of the Company shall not exceed $20.0 million at
any one time.

    "Permitted Liens" means (a) Liens securing Indebtedness incurred pursuant to
clause (a) of the definition of "Permitted Indebtedness," (b) Liens in favor of
the Company or any of its Restricted Subsidiaries, (c) Liens on property of a
Person existing at the time such Person is merged into or consolidated with the
Company or any Restricted Subsidiary of the Company, provided that such Liens
were in existence prior to the contemplation of such merger or consolidation and
do not extend to any property other than those of the Person merged into or
consolidated with the Company or any of its Restricted Subsidiaries, (d) Liens
on property existing at the time of acquisition thereof by the Company or any
Restricted Subsidiary of the Company, provided that such Liens were in existence
prior to the contemplation of such acquisition and do not extend to any other
property, (e) Liens to secure the performance of statutory obligations, surety
or appeal bonds, bid or performance bonds, insurance obligations or other
obligations of a like nature incurred in the ordinary course of business, (f)
Liens securing Hedging Obligations, (g) Liens existing on the Issue Date, (h)
Liens securing Non-Recourse Debt, (i) any interest or title of a lessor under a
Capital Lease Obligation or an operating lease, (j) Liens arising by reason of
deposits necessary to obtain standby letters of credit in the ordinary course of
business (including deposits necessary to obtain standby letters of credit), (k)
Liens incurred or deposits made in the ordinary course of business in connection
with workers' compensation, unemployment insurance and other types of social
security and related benefits, (l) easements, rights of way restrictions and
other similar charges or encumbrances not interfering in any material respect
with the business of the Company or any Restricted Subsidiary, (m) any other
Liens imposed by operation of law which do not materially affect the Company's
or any Guarantor's ability to perform its obligations under the Notes or any
Subsidiary Guarantee, (n) any attachment or judgment Lien, unless the judgment
it secures shall not, within 60 days after the entry thereof, have been
discharged or execution thereof stayed pending appeal, or shall not have been
discharged within 60 days after the expiration of any such stay, (o) Liens to
secure Purchase Money

                                    - 13 -
<PAGE>
 
Indebtedness, which Liens shall not extend to any other property or assets of
the Company or a Restricted Subsidiary (other than any associated accounts,
contracts and insurance proceeds), (p) Liens securing Permitted Refinancing
Indebtedness with respect to any Indebtedness referred to in clause (o) above,
and (q) Liens incurred in the ordinary course of business of the Company or any
Restricted Subsidiary of the Company with respect to obligations that do not
exceed $5.0 million at any one time outstanding and that (i) are not incurred in
connection with the borrowing of money or the obtaining of advances or credit
(other than trade credit in the ordinary course of business) and (ii) do not in
the aggregate materially detract from the value of the property or materially
impair the use thereof in the operation of business by the Company or such
Restricted Subsidiary.

    "Permitted Refinancing Indebtedness" means any Indebtedness of the Company
or any of its Restricted Subsidiaries issued in exchange for, or the net
proceeds of which are used to extend, refinance, renew, replace, defease or
refund other Indebtedness of the Company or any of its Restricted Subsidiaries;
provided, however, that (a) the principal amount (or accreted value, if
applicable) of such Permitted Refinancing Indebtedness does not exceed the
principal amount of (or accreted value, if applicable), plus premium, if any,
and accrued interest on, the Indebtedness so extended, refinanced, renewed,
replaced, defeased or refunded (plus the amount of reasonable expenses incurred
in connection therewith), (b) such Permitted Refinancing Indebtedness has a
final maturity date no earlier than the final maturity date of, and has a
Weighted Average Life to Maturity equal to or greater than the Weighted Average
Life to Maturity of, the Indebtedness being extended, refinanced, renewed,
replaced, defeased or refunded, (c) if the Indebtedness being extended,
refinanced, renewed, replaced, defeased or refunded is subordinated in right of
payment to the Notes, such Permitted Refinancing Indebtedness is subordinated in
right of payment to the Notes on terms at least as favorable, taken as a whole,
to the Holders of Notes as those contained in the documentation governing the
Indebtedness being extended, refinanced, renewed, replaced, defeased or refunded
and (d) such Indebtedness is incurred either by the Company or by the Restricted
Subsidiary that is the obligor on the Indebtedness being extended, refinanced,
renewed, replaced, defeased or refunded; provided, however, that a Restricted
Subsidiary that is also a Guarantor may guarantee Permitted Refinancing
Indebtedness incurred by the Company, whether or not such Restricted Subsidiary
was an obligor or guarantor of the Indebtedness being extended, refinanced,
renewed, replaced, defeased or refunded; provided, further, however, that if
such Permitted Refinancing Indebtedness is subordinated to the Notes, such
guarantee shall be subordinated to such Restricted Subsidiary's Subsidiary
Guarantee to at least the same extent.

    "Person" means any individual, corporation, partnership, limited liability
company, joint venture, association, joint-stock company, trust, unincorporated
organization or government or agency or political subdivision thereof (including
any subdivision or ongoing business of any such entity or substantially all of
the assets of any such entity, subdivision or business).

    "Principal Business" means (a) the business of the exploration for, and
development, acquisition, production, processing, marketing, refining, storage
and transportation of, hydrocarbons, (b) any related energy and natural resource
business, (c) any business currently engaged in by the Company or its
Subsidiaries, (d) convenience stores, retails service stations, truck stops and
other public accommodations in connection therewith and (e) any activity or
business that is a reasonable extension, development or expansion of any of the
foregoing.

                                    - 14 -
<PAGE>
 
    "Purchase Money Indebtedness" means Indebtedness incurred for the purpose of
(a) financing all or any part of the purchase price of any real or personal
property or assets incurred prior to, at the time of, or within 120 days after,
the acquisition of such property or (ii) financing all or any part of the cost
of construction of any such property or assets, provided that the amount of any
such financing shall not exceed the amount expended in the acquisition of, or
the construction of, such property or assets.

    "QIB" means a "qualified institutional buyer" as defined in Rule 144A under
the Securities Act.

    "Qualified Equity Offering" means (a) any sale of Equity Interests (other
than Disqualified Stock) of the Company pursuant to an underwritten offering
registered under the Securities Act or (b) any sale of Equity Interests (other
than Disqualified Stock) of the Company so long as, at the time of consummation
of such sale, the Company has a class of common equity securities registered
pursuant to Section 12(b) or Section 12(g) under the Exchange Act.

    "Registration Rights Agreement" means (a) the Registration Rights Agreement,
dated as of February 9, 1998, by and between the Company and the Initial
Purchaser relating to the Original Notes and (b) any similar agreement that the
Company may enter into in relation to any other Series A Notes, in each case as
such agreement may be amended, modified or supplemented from time to time.

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

    "Regulation S Global Note" means a Regulation S Temporary Global Note or
Regulation S Permanent Global Note, as appropriate.

    "Regulation S Permanent Global Note" means a permanent global note that
contains the paragraph referred to in footnote 1 and the additional schedule
referred to in footnote 3 to the form of the Note attached hereto as Exhibit
A-1, and that is deposited with the Note Custodian and registered in the name of
the Depository, representing a series of Notes sold in reliance on Regulation S.

    "Regulation S Temporary Global Note" means a single temporary global senior
note in the form of the Note attached hereto as Exhibit A-2 that is deposited
with the Note Custodian and registered in the name of the Depository,
representing a series of Notes sold in reliance on Regulation S.

    "Responsible Officer," when used with respect to the Trustee, means any
officer within the Corporate Trust Department of the Trustee (or any successor
department of the Trustee) or any other officer of the Trustee customarily
performing functions similar to those performed by any of the above designated
officers and also means, with respect to a particular corporate trust matter,
any other officer to whom such matter is referred because of his knowledge of
and familiarity with the particular subject.

                                    - 15 -
<PAGE>
 
    "Restricted Beneficial Interest" means any beneficial interest of a
Participant or Indirect Participant in a Restricted Global Note.

    "Restricted Definitive Notes" means the Definitive Notes that are required
to bear the legend set forth in Section 2.06(f) hereof.

    "Restricted Global Notes" means the 144A Global Note and the Regulation S
Global Note, each of which is required to bear the legend set forth in Section
2.06(f) hereof.

    "Restricted Investment" means an Investment other than a Permitted
Investment.

    "Restricted Subsidiary" of a Person means any Subsidiary of such Person that
is not an Unrestricted Subsidiary.

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

    "SEC" means the Securities and Exchange Commission.

    "Securities Act" means the Securities Act of 1933, as amended.

    "Stated Maturity" means, with respect to any installment of interest or
principal on any series of Indebtedness, the date on which such payment of
interest or principal was scheduled to be paid in the original documentation
governing such Indebtedness, and shall not include any contingent obligations to
repay, redeem or repurchase any such interest or principal prior to the date
originally scheduled for the payment thereof.

    "Subsidiary" means, with respect to any Person, (a) any corporation,
association or other business entity of which more than 50% of the total voting
power of shares of Capital Stock entitled (without regard to the occurrence of
any contingency) to vote in the election of directors, managers or trustees
thereof is at the time owned or controlled, directly or indirectly, by such
Person or one or more of the other Subsidiaries of that Person (or a combination
thereof) and (b) any partnership (i) the sole general partner or the managing
general partner of which is such Person or a Subsidiary of such Person or (ii)
the only general partners of which are such Person or of one or more
Subsidiaries of such Person (or any combination thereof).

    "Subsidiary Guarantees" means the joint and several guarantees that may be
issued by all of the Guarantors pursuant to Article 10 hereof.

    "TIA" means the Trust Indenture Act of 1939 (15 U.S.C. (S)(S) 77aaa-77bbbb)
as in effect on the date on which this Indenture is qualified under the TIA.

    "Transfer Restricted Securities" means securities that bear or are required
to bear the legend set forth in Section 2.06(f) hereof.

                                    - 16 -
<PAGE>
 
    "Trustee" means the party named as such above until a successor replaces it
in accordance with the applicable provisions of this Indenture and thereafter
means the successor serving hereunder.

    "Unrestricted Global Notes" means one or more Global Notes that do not and
are not required to bear the legend set forth in Section 2.06(f) hereof.

    "Unrestricted Subsidiary" means any Subsidiary that is designated by the
Board of Directors as an Unrestricted Subsidiary pursuant to a resolution of the
Board of Directors, but only to the extent that such Subsidiary at the time of
such designation (a) has no Indebtedness other than Non-Recourse Debt, (b) is
not party to any agreement, contract, arrangement or understanding with the
Company or any Restricted Subsidiary of the Company unless such agreement,
contract, arrangement or understanding does not violate the terms of this
Indenture described in Section 4.11 hereof, and (c) is a Person with respect to
which neither the Company nor any of its Restricted Subsidiaries has any direct
or indirect obligation (i) to subscribe for additional Equity Interests or (ii)
to maintain or preserve such Person's financial condition or to cause such
Person to achieve any specified levels of operating results, in each case,
except to the extent otherwise permitted by this Indenture.  Any such
designation by the Board of Directors shall be evidenced to the Trustee by
filing with the Trustee a certified copy of the resolution of the Board of
Directors giving effect to such designation and an Officers' Certificate
certifying that such designation complied with the foregoing conditions and was
permitted by Section 4.07 hereof. If, at any time, any Unrestricted Subsidiary
would fail to meet the foregoing requirements as an Unrestricted Subsidiary, it
shall thereafter cease to be an Unrestricted Subsidiary for purposes of this
Indenture and any Indebtedness of such Subsidiary shall be deemed to be incurred
by a Restricted Subsidiary of the Company as of such date (and, if such
Indebtedness is not permitted to be incurred as of such date pursuant to Section
4.09 hereof, the Company shall be in default of such covenant).  The Board of
Directors of the Company may at any time designate any Unrestricted Subsidiary
to be a Restricted Subsidiary, provided that such designation shall be deemed to
be an incurrence of Indebtedness by a Restricted Subsidiary of the Company of
any outstanding Indebtedness of such Unrestricted Subsidiary and such
designation shall only be permitted if (A) such Indebtedness is permitted by
Section 4.09 hereof, calculated on a pro forma basis as if such designation had
occurred at the beginning of the four-quarter reference period, and (B) no
Default or Event of Default would be in existence following such designation.

    "Weighted Average Life to Maturity" means, when applied to any Indebtedness
at any date, the number of years obtained by dividing (a) the sum of the
products obtained by multiplying (i) the amount of each then remaining
installment, sinking fund, serial maturity or other required payments of
principal, including payment at final maturity, in respect thereof, by (ii) the
number of years (calculated to the nearest one-twelfth) that will elapse between
such date and the making of such payment, by (b) the then outstanding principal
amount of such Indebtedness.

    "Wholly Owned Restricted Subsidiary" of any Person means a Restricted
Subsidiary of such Person to the extent (a) all of the outstanding Capital Stock
or other ownership interests of which (other than directors' qualifying shares)
shall at the time be owned directly or indirectly by such Person or (b) such
Restricted Subsidiary is organized in a foreign jurisdiction and is required by
the applicable laws and regulations of such foreign jurisdiction to be partially
owned by the government

                                    - 17 -
<PAGE>
 
of such foreign jurisdiction or individual or corporate citizens of such foreign
jurisdiction in order for such Restricted Subsidiary to transact business in
such foreign jurisdiction, provided that such Person, directly or indirectly,
owns the remaining Capital Stock or ownership interests in such Restricted
Subsidiary and, by contract or otherwise, controls the management and business
of such Restricted Subsidiary and derives the economic benefits of ownership of
such Restricted Subsidiary to substantially the same extent as if such
Restricted Subsidiary were a wholly owned Restricted Subsidiary.

    "Working Capital Facility" includes the Credit Facility and any other
working capital facilities entered into by the Company or any of its Restricted
Subsidiaries, including any related notes, guarantees, collateral documents,
instruments and agreements executed in connection therewith, in each case as
amended, restated, modified, supplemented, extended, renewed, replaced,
refinanced or restructured from time to time, whether by the same or any other
agent or agents, lender or group of lenders, whether represented by one or more
agreements and whether one or more Subsidiaries are borrowers, or guarantors
thereunder or parties thereto.

Section 1.02. Other Definitions.

                                                             Defined in
   Term                                                        Section

  "Affiliate Transaction". . . . . . . . . . . . . .              4.11
  "Asset Sale Offer" . . . . . . . . . . . . . . . .              3.09
  "Change of Control Offer". . . . . . . . . . . . .              4.15
  "Change of Control Payment". . . . . . . . . . . .              4.15
  "Change of Control Payment Date" . . . . . . . . .              4.15
  "Covenant Defeasance". . . . . . . . . . . . . . .              8.03
  "DTC". . . . . . . . . . . . . . . . . . . . . . .              2.03
  "Event of Default" . . . . . . . . . . . . . . . .              6.01
  "Excess Proceeds". . . . . . . . . . . . . . . . .              4.10
  "incur" or "incurrence". . . . . . . . . . . . . .              4.09
  "Legal Defeasance" . . . . . . . . . . . . . . . .              8.02
  "Offer Amount" . . . . . . . . . . . . . . . . . .              3.09
  "Offer Period" . . . . . . . . . . . . . . . . . .              3.09
  "Paying Agent" . . . . . . . . . . . . . . . . . .              2.03
  "Payment Default". . . . . . . . . . . . . . . . .              6.01
  "Purchase Date". . . . . . . . . . . . . . . . . .              3.09
  "Registrar". . . . . . . . . . . . . . . . . . . .              2.03
  "Restricted Payments". . . . . . . . . . . . . . .              4.07

                                    - 18 -
<PAGE>
 
Section 1.03.  Incorporation by Reference of Trust Indenture Act.

     Whenever this Indenture refers to a provision of the TIA, the provision is
incorporated by reference in and made a part of this Indenture.  Any terms
incorporated in this Indenture that are defined by the TIA, defined by TIA
reference to another statute or defined by SEC rule under the TIA have the
meanings so assigned to them.

Section 1.04.  Rules of Construction.

     Unless the context otherwise requires: 

          (1)  a term has the meaning assigned to it;

          (2)  an accounting term not otherwise defined has the meaning assigned
     to it in accordance with GAAP;

          (3)  "or" is not exclusive;

          (4)  words in the singular include the plural, and in the plural
     include the singular;

          (5)  provisions apply to successive events and transactions; and

          (6)  references to sections of or rules under the Securities Act or
     the Exchange Act shall be deemed to include substitute, replacement or
     successor sections or rules adopted by the SEC from time to time.

                                   ARTICLE 2
                                   THE NOTES

Section 2.01.  Form and Dating.

     The Notes and the Trustee's certificate of authentication shall be
substantially in the form of Exhibit A-1 or Exhibit A-2 hereto.  The Notes may
have notations, legends or endorsements required by law, stock exchange rule or
usage.  Each Note shall be dated the date of its authentication.  The Notes
shall be issued in denominations of $1,000 and integral multiples thereof.

     The Series A Notes and the Series B Notes shall be considered collectively
to be a single class for all purposes of this Indenture, including, without
limitation, waivers, amendments, redemptions and offers to purchase.

     The terms and provisions contained in the Notes shall constitute, and are
hereby expressly made, a part of this Indenture and the Company, the Guarantors
and the Trustee, by their execution and delivery of this Indenture, expressly
agree to such terms and provisions and to be bound thereby.

     (a)  Global Notes.  Except as provided in Section 2.01(c), Series A Notes
offered and sold to QIBs in reliance on Rule 144A shall be issued initially in
the form of one or more 144A Global

                                    - 19 -
<PAGE>
 
Notes, which shall be deposited on behalf of the purchasers of the Series A
Notes represented thereby with the Note Custodian and registered in the name of
the Depository or a nominee of the Depository, duly executed by the Company and
authenticated by the Trustee as hereinafter provided. The aggregate principal
amount of the 144A Global Notes may from time to time be increased or decreased
by adjustments made on the records of the Trustee and the Depository or its
nominee, as the case may be, in connection with transfers of interests as
hereinafter provided.

     Series A Notes offered and sold in reliance on Regulation S, if any, shall
be issued initially in the form of the Regulation S Temporary Global Note, which
shall be deposited on behalf of the purchasers of the Series A Notes represented
thereby with the Note Custodian and registered in the name of the Depository or
the nominee of the Depository for the accounts of designated agents holding on
behalf of Euroclear or Cedel, duly executed by the Company and authenticated by
the Trustee as hereinafter provided.  The "40-day restricted period" (as defined
in Regulation S) shall be terminated upon the receipt by the Trustee of (i) a
written certificate from the Depository, together with copies of certificates
from Euroclear and Cedel certifying that they have received certification of
non-United States beneficial ownership of 100% of the aggregate principal amount
of the Regulation S Temporary Global Note (except to the extent of any
beneficial owners thereof who acquired an interest therein pursuant to another
exemption from registration under the Securities Act and who will take delivery
of a beneficial ownership interest in a 144A Global Note, all as contemplated by
Section 2.06(a)(ii) hereof), and (ii) an Officers' Certificate from the Company.
Following the termination of the 40-day restricted period, beneficial interests
in the Regulation S Temporary Global Note shall be exchanged for beneficial
interests in one or more Regulation S Permanent Global Notes pursuant to the
Applicable Procedures.  Simultaneously with the authentication of Regulation S
Permanent Global Notes, the Trustee shall cancel the Regulation S Temporary
Global Note.  The aggregate principal amount of the Regulation S Temporary
Global Note and the Regulation S Permanent Global Notes may from time to time be
increased or decreased by adjustments made on the records of the Trustee and the
Depository or its nominee, as the case may be, in connection with transfers of
interests as hereinafter provided.

     Each Global Note shall represent such of the outstanding Notes as shall be
specified therein and each shall provide that it shall represent the aggregate
amount of outstanding Notes from time to time endorsed thereon and that the
aggregate amount of outstanding Notes represented thereby may from time to time
be reduced or increased, as appropriate, to reflect exchanges, redemptions and
transfers of interests.  Any endorsement of a Global Note to reflect the amount
of any increase or decrease in the amount of outstanding Notes represented
thereby shall be made by the Trustee or the Note Custodian, at the direction of
the Trustee, in accordance with instructions given by the Holder thereof as
required by Section 2.06 hereof.

     The provisions of the "Operating Procedures of the Euroclear System" and
"Terms and Conditions Governing Use of Euroclear" and the "Management
Regulations" and "Instructions to Participants" of Cedel shall be applicable to
interests in the Regulation S Temporary Global Note and the Regulation S
Permanent Global Notes, if any, that are held by Participants through Euroclear
or Cedel.  The Trustee shall have no obligation to notify Holders of any such
procedures or to monitor or enforce compliance with the same.

                                    - 20 -
<PAGE>
 
     (b)  Book-Entry Provisions.  Participants shall have no rights either under
this Indenture with respect to any Global Note held on their behalf by the
Depository or by the Note Custodian as custodian for the Depository or under
such Global Note, and the Depository may be treated by the Company, the Trustee
and any Agent of the Company or the Trustee as the absolute owner of such Global
Note for all purposes whatsoever.  Notwithstanding the foregoing, nothing herein
shall prevent the Company, the Trustee or any Agent of the Company or the
Trustee from giving effect to any written certification, proxy or other
authorization furnished by the Depository or impair, as between the Depository
and its Participants, the operation of customary practices of such Depository
governing the exercise of the rights of an owner of a beneficial interest in any
Global Note.

     (c)  Definitive Notes.  Series A Notes offered and sold to Institutional
Accredited Investors who are not QIBs otherwise than in reliance on Regulation
S, if any, or to QIBs who elect to take their Series A Notes in definitive form
shall be issued initially in the form of Definitive Notes, duly executed by the
Company and authenticated by the Trustee as hereinafter provided.

Section 2.02.  Execution and Authentication.

     One Officer shall sign the Notes for the Company by manual or facsimile
signature.  The Company's seal shall be reproduced on the Notes and may be in
facsimile form.

     If an Officer whose signature is on a Note no longer holds that office at
the time a Note is authenticated, the Note shall nevertheless be valid.

     A Note shall not be valid until authenticated by the manual signature of an
authorized signatory of the Trustee.  Such signature shall be conclusive
evidence that the Note has been authenticated under this Indenture.  The form of
Trustee's certificate of authentication to be borne by the Notes shall be
substantially as set forth in Exhibit A-1 or Exhibit A-2 hereto.

     Each Note shall be dated the date of its authentication.

     The Trustee shall authenticate (i) the Series A Notes for original issue on
the Issue Date in the aggregate principal amount of $70,000,000 (the "Offered
Notes"), (ii) additional Series A Notes for original issue from time to time
after the Issue Date in such additional principal amounts not to exceed
$5,000,000 as may be set forth in a written order of the Company as described in
this sentence and (iii) the Series B Notes from time to time for issue only in
exchange for a like principal amount of Series A Notes, in each case upon a
written order of the Company signed by one Officer, which written order shall
specify (a) the amount of Notes to be authenticated and the date of original
issue thereof, (b) whether the Notes are Series A Notes or Series B Notes, and
(c) the amount of Notes to be issued in global form or definitive form.  The
aggregate principal amount of Notes outstanding at any time may not exceed
$70,000,000 plus any additional principal amounts as may be issued and
authenticated pursuant to clause (ii) of this paragraph, except as provided in
Section 2.07 hereof.

     The Trustee may appoint an authenticating agent acceptable to the Company
to authenticate Notes.  An authenticating agent may authenticate Notes whenever
the Trustee may do so.  Each reference in this Indenture to authentication by
the Trustee includes authentication by such agent.

                                    - 21 -
 
<PAGE>
 
An authenticating agent has the same rights as an Agent to deal with the
Company, any Guarantor or an Affiliate of the Company.

Section 2.03.  Registrar and Paying Agent.

     The Company shall maintain an office or agency where Notes may be presented
for registration of transfer or for exchange ("Registrar") and an office or
agency in the City of New York where Notes may be presented for payment ("Paying
Agent").  The Registrar shall keep a register of the Notes and of their transfer
and exchange.  The Company may appoint one or more co-registrars and one or more
additional paying agents.  The term "Registrar" includes any co-registrar and
the term "Paying Agent" includes any additional paying agent.  The Company may
change any Paying Agent or Registrar without notice to any Holder.  The Company
shall notify the Trustee in writing of the name and address of any Agent not a
party to this Indenture.  If the Company fails to appoint or maintain another
entity as Registrar or Paying Agent, the Trustee shall act as such.  The Company
shall enter into an appropriate agency agreement with any Agent not a party to
this Indenture, and such agreement shall incorporate the TIA's provisions of
this Indenture that relate to such Agent.  The Company or any of its
Subsidiaries may act as Paying Agent or Registrar.

     The Company initially appoints The Depository Trust Company ("DTC") to act
as Depository with respect to the Global Notes.

     The Company initially appoints the Trustee to act as the Registrar and
Paying Agent and to act as Note Custodian with respect to the Global Notes.

Section 2.04.  Paying Agent to Hold Money in Trust.

     The Company shall require each Paying Agent other than the Trustee to agree
in writing that the Paying Agent will hold in trust for the benefit of Holders
or the Trustee all money held by the Paying Agent for the payment of principal
of or premium, interest or Liquidated Damages, if any, on the Notes, and will
notify the Trustee of any default by the Company in making any such payment.
While any such default continues, the Trustee may require a Paying Agent to pay
all money held by it to the Trustee.  The Company at any time may require a
Paying Agent to pay all money held by it to the Trustee.  Upon payment over to
the Trustee, the Paying Agent (if other than the Company or a Subsidiary) shall
have no further liability for the money.  If the Company or a Subsidiary acts as
Paying Agent, it shall segregate and hold in a separate trust fund for the
benefit of the Holders all money held by it as Paying Agent.  Upon any
bankruptcy or reorganization proceedings relating to the Company, the Trustee
shall serve as Paying Agent for the Notes.

Section 2.05.  Holder Lists.

     The Trustee shall preserve in as current a form as is reasonably
practicable the most recent list available to it of the names and addresses of
all Holders and shall otherwise comply with TIA (S) 312(a). If the Trustee is
not the Registrar, the Company shall furnish to the Trustee at least seven
Business Days before each interest payment date and at such other times as the
Trustee may request

                                    - 22 -
<PAGE>
 
in writing, a list in such form and as of such date as the Trustee may
reasonably require of the names and addresses of the Holders of Notes and the
Company shall otherwise comply with TIA (S) 312(a).

Section 2.06.  Transfer and Exchange.

     (a)  Transfer and Exchange of Global Notes.  The transfer and exchange of
Global Notes or beneficial interests therein shall be effected through the
Depository, in accordance with this Indenture and the Applicable Procedures.
Beneficial interests in a Global Note may be transferred to Persons who take
delivery thereof in the form of a beneficial interest in the same Global Note in
accordance with the Applicable Procedures and, in the case of a Transfer
Restricted Security, transfer restrictions set forth in the legend in subsection
(f) of this Section 2.06. Transfers of beneficial interests in the Global Notes
to Persons required to take delivery thereof in the form of an interest in
another Global Note shall be permitted as follows:

          (i)  144A Global Note to Regulation S Global Note.  If, at any time,
     an owner of a beneficial interest in a 144A Global Note deposited with the
     Depository (or the Trustee as custodian for the Depository) wishes to
     transfer its beneficial interest in such 144A Global Note to a Person who
     is required or permitted to take delivery thereof in the form of an
     interest in a Regulation S Global Note, such owner shall, subject to the
     Applicable Procedures, exchange or cause the exchange of such interest for
     an equivalent beneficial interest in a Regulation S Global Note as provided
     in this Section 2.06(a)(i). Upon receipt by the Trustee of (A) instructions
     given in accordance with the Applicable Procedures from *a Participant
     directing the Trustee to credit or cause to be credited a beneficial
     interest in the Regulation S Global Note in an amount equal to the
     beneficial interest in the 144A Global Note to be transferred, (B) a
     written order given in accordance with the Applicable Procedures containing
     information regarding the Participant account of the Depository and the
     Euroclear or Cedel account to be credited with such increase and (C) in the
     case of Global Notes that are Transfer Restricted Securities, a certificate
     in the form of Exhibit B-1 hereto given by the owner of such beneficial
     interest stating that the transfer of such interest has been made in
     compliance with the transfer restrictions applicable to the Global Notes
     and pursuant to and in accordance with Rule 903 or Rule 904 of Regulation
     S, then the Trustee, as Registrar, shall instruct the Depository to reduce
     or cause to be reduced the aggregate principal amount of the applicable
     144A Global Note and to increase or cause to be increased the aggregate
     principal amount of the applicable Regulation S Global Note by the
     principal amount of the beneficial interest in the 144A Global Note to be
     transferred, to credit or cause to be credited to the account of the Person
     specified in such instructions, a beneficial interest in the Regulation S
     Global Note equal to the reduction in the aggregate principal amount of the
     144A Global Note, and to debit, or cause to be debited, from the account of
     the Person making such transfer the beneficial interest in the 144A Global
     Note that is being transferred.

          (ii) Regulation S Global Note to 144A Global Note.  If, at any time,
     after the expiration of the 40-day restricted period, an owner of a
     beneficial interest in a Regulation S Global Note deposited with the
     Depository (or with the Trustee as custodian for the Depository) wishes to
     transfer its beneficial interest in such Regulation S Global Note to a
     Person who is required or permitted to take delivery thereof in the form of
     an interest in a 144A Global Note, such owner shall, subject to the
     Applicable Procedures, exchange or

                                    - 23 -
<PAGE>
 
     cause the exchange of such interest for an equivalent beneficial interest
     in a 144A Global Note as provided in this Section 2.06(a)(ii). Upon receipt
     by the Trustee of (A) instructions from Euroclear or Cedel, if applicable,
     and the Depository, directing the Trustee, as Registrar, to credit or cause
     to be credited a beneficial interest in the 144A Global Note equal to the
     beneficial interest in the Regulation S Global Note to be transferred, such
     instructions to contain information regarding the Participant account with
     the Depository to be credited with such increase, (B) a written order given
     in accordance with the Applicable Procedures containing information
     regarding the participant account of the Depository and (C) in the case of
     Global Notes that are Transfer Restricted Securities, a certificate in the
     form of Exhibit B-2 attached hereto given by the owner of such beneficial
     interest stating (1) if the transfer is pursuant to Rule 144A, that the
     Person transferring such interest in a Regulation S Global Note reasonably
     believes that the Person acquiring such interest in a 144A Global Note is a
     QIB and is obtaining such beneficial interest in a transaction meeting the
     requirements of Rule 144A, (2) that the transfer complies with the
     requirements of Rule 144 under the Securities Act, (3) if the transfer is
     pursuant to any other exemption from the registration requirements of the
     Securities Act, that the transfer of such interest has been made in
     compliance with the transfer restrictions applicable to the Global Notes
     and pursuant to and in accordance with the requirements of the exemption
     claimed, such statement to be supported by an Opinion of Counsel from the
     transferee or the transferor in form reasonably acceptable to the Company
     and to the Registrar and in each case of clause (1), (2) or (3) above, in
     accordance with any applicable securities laws of any state of the United
     States or any other applicable jurisdiction or (4) such transfer is being
     effected pursuant to an effective registration statement under the
     Securities Act, then the Trustee, as Registrar, shall instruct the
     Depository to reduce or cause to be reduced the aggregate principal amount
     of such Regulation S Global Note and to increase or cause to be increased
     the aggregate principal amount of the applicable 144A Global Note by the
     principal amount of the beneficial interest in the Regulation S Global Note
     to be transferred, and the Trustee, as Registrar, shall instruct the
     Depository, concurrently with such reduction, to credit or cause to be
     credited to the account of the Person specified in such instructions a
     beneficial interest in the applicable 144A Global Note equal to the
     reduction in the aggregate principal amount of such Regulation S Global
     Note and to debit or cause to be debited from the account of the Person
     making such transfer the beneficial interest in the Regulation S Global
     Note that is being transferred.

     (b)  Transfer and Exchange of Definitive Notes.  When Definitive Notes are
presented by a Holder to the Registrar with a request to register the transfer
of the Definitive Notes or to exchange such Definitive Notes for an equal
principal amount of Definitive Notes of other authorized denominations, the
Registrar shall register the transfer or make the exchange as requested only if
the Definitive Notes are presented or surrendered for registration of transfer
or exchange, are endorsed or accompanied by a written instrument of transfer in
form satisfactory to the Registrar duly executed by such Holder or by his
attorney, duly authorized in writing and the Registrar receives the following
documentation (all of which may be submitted by facsimile):

          (i)  in the case of Definitive Notes that are Transfer Restricted
     Securities, such request shall be accompanied by the following additional
     information and documents, as applicable:

                                    - 24 -
<PAGE>
 
               (A)  if such Transfer Restricted Security is being delivered to
          the Registrar by a Holder for registration in the name of such Holder,
          without transfer, or such Transfer Restricted Security is being
          transferred (1) to the Company or any of its Subsidiaries or (2)
          pursuant to an effective registration statement under the Securities
          Act, a certification to that effect from such Holder (in substantially
          the form of Exhibit B-3 hereto);

               (B)  if such Transfer Restricted Security is being transferred to
          a QIB in accordance with Rule 144A under the Securities Act or
          pursuant to an exemption from registration in accordance with Rule 144
          under the Securities Act or pursuant to an effective registration
          statement under the Securities Act, a certification to that effect
          from such Holder (in substantially the form of Exhibit B-3 hereto);

               (C)  if such Transfer Restricted Security is being transferred to
          a Non-U.S. Person in an offshore transaction in accordance with Rule
          904 under the Securities Act, a certification to that effect from such
          Holder (in substantially the form of Exhibit B-3 hereto but containing
          the certification called for by clauses (1) through (4) of Exhibit B-1
          hereto); or

               (D)  if such Transfer Restricted Security is being transferred to
          an Institutional Accredited Investor in reliance on an exemption from
          the registration requirements of the Securities Act other than those
          listed in subparagraph (B) or (C) above, a certification to that
          effect from such Holder (in substantially the form of Exhibit B-3
          hereto), and a certification substantially in the form of Exhibit C
          hereto from the transferee, and, if such transfer is in respect of an
          aggregate principal amount of Notes of less than $100,000, an Opinion
          of Counsel acceptable to the Company that such transfer is in
          compliance with the Securities Act and any applicable blue sky laws of
          any state of the United States.

     (c)  Transfer of a Beneficial Interest in a 144A Global Note or Regulation
S Permanent Global Note for a Definitive Note.

          (i)  Any Person having a beneficial interest in a 144A Global Note or
     Regulation S Permanent Global Note may upon request, subject to the
     Applicable Procedures, exchange such beneficial interest for a Definitive
     Note, upon receipt by the Trustee of written instructions or such other
     form of instructions as is customary for the Depository (or Euroclear or
     Cedel, if applicable), from the Depository or its nominee on behalf of any
     Person having a beneficial interest in a 144A Global Note or Regulation S
     Permanent Global Note, and, in the case of a Transfer Restricted Security,
     the following additional information and documents (all of which may be
     submitted by facsimile):

               (A)  if such beneficial interest is being transferred to the
          Person designated by the Depository as being the beneficial owner or
          to the Company or any of its Subsidiaries, a certification to that
          effect from such Person (in substantially the form of Exhibit B-4
          hereto);

                                    - 25 -
<PAGE>
 
               (B)  if such beneficial interest is being transferred to a QIB in
          accordance with Rule 144A under the Securities Act or pursuant to an
          exemption from registration in accordance with Rule 144 under the
          Securities Act or pursuant to an effective registration statement
          under the Securities Act, a certification to that effect from the
          transferor (in substantially the form of Exhibit B-4 hereto);

               (C)  if such beneficial interest is being transferred to a
          Non-U.S. Person in an offshore transaction in accordance with Rule 904
          under the Securities Act, a certification to that effect from the
          transferor (in substantially the form of Exhibit B-4 hereto but
          containing the certification called for by clauses (1) through (4) of
          Exhibit B-1 hereto); or

               (D)  if such beneficial interest is being transferred to an
          Institutional Accredited Investor, pursuant to a private placement
          exemption from the registration requirements of the Securities Act
          other than those listed in subparagraph (B) or (C) above, a
          certification to that effect from such Holder (in substantially the
          form of Exhibit B-4 hereto), a certification from the applicable
          transferee (in substantially the form of Exhibit C hereto) and, if
          such transfer is in respect of an aggregate principal amount of less
          than $100,000, an Opinion of Counsel acceptable to the Company that
          such transfer is in compliance with the Securities Act and any
          applicable blue sky laws of any State of the United States;

     in which case the Trustee or the Note Custodian, at the direction of the
     Trustee, shall, in accordance with the standing instructions and procedures
     existing between the Depository and the Note Custodian, cause the aggregate
     principal amount of 144A Global Notes or Regulation S Permanent Global
     Notes, as applicable, to be reduced accordingly and, following such
     reduction, the Company shall execute and, the Trustee shall authenticate
     and deliver to the transferee a Definitive Note in the appropriate
     principal amount.

          (ii) Definitive Notes issued in exchange for a beneficial interest in
     a 144A Global Note or Regulation S Permanent Global Note, as applicable,
     pursuant to this Section 2.06(c) shall be registered in such names and in
     such authorized denominations as the Depository, pursuant to instructions
     from its direct or Indirect Participants or otherwise, shall instruct the
     Trustee.  The Trustee shall deliver such Definitive Notes to the Persons in
     whose names such Notes are so registered.  Following any such issuance of
     Definitive Notes, the Trustee, as Registrar, shall instruct the Depository
     to reduce or cause to be reduced the aggregate principal amount of the
     applicable Global Note to reflect the transfer.

     (d)  Restrictions on Transfer and Exchange of Global Notes.
Notwithstanding any other provision of this Indenture (other than the provisions
set forth in subsection (f) of this Section 2.06), a Global Note may not be
transferred as a whole except by the Depository to a nominee of the Depository
or by a nominee of the Depository to the Depository or another nominee of the
Depository or by the Depository or any such nominee to a successor Depository or
a nominee of such successor Depository.

                                    - 26 -
<PAGE>
 
     (e)  Authentication of Definitive Notes in Absence of Depository.  If at
     any time:

          (i)  the Depository for the Notes notifies the Company that the
     Depository is unwilling or unable to continue as Depository for the Global
     Notes and a successor Depository for the Global Notes is not appointed by
     the Company within 90 days after delivery of such notice; or

          (ii) the Company, at its sole discretion, notifies the Trustee in
     writing that it elects to cause the issuance of Definitive Notes under this
     Indenture,

then the Company shall execute, and the Trustee shall, upon receipt of an
authentication order in accordance with Section 2.02 hereof, authenticate and
deliver, Definitive Notes in an aggregate principal amount equal to the
principal amount of the Global Notes in exchange for such Global Notes.

     (f)  Legends.

          (i)  Except as permitted by the following paragraphs (ii), (iii) and
     (iv), each Note certificate evidencing a Global Note or a Definitive Note
     (and all Notes issued in exchange therefor or substitution thereof) shall
     bear a legend in substantially the following form:

               THE NOTE (OR ITS PREDECESSOR) EVIDENCED HEREBY HAS NOT BEEN
          REGISTERED UNDER THE U.S. SECURITIES ACT OF 1933, AS AMENDED (THE
          "SECURITIES ACT"), OR ANY STATE SECURITIES LAWS, AND, ACCORDINGLY, MAY
          NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED EXCEPT AS SET FORTH IN
          THE FOLLOWING SENTENCE.  EACH PURCHASER OF THE NOTE EVIDENCED HEREBY
          IS HEREBY NOTIFIED THAT THE SELLER MAY BE RELYING ON THE EXEMPTION
          FROM THE PROVISIONS OF SECTION 5 OF THE SECURITIES ACT PROVIDED BY
          RULE 144A THEREUNDER.  BY ITS ACQUISITION HEREOF, THE HOLDER:
          REPRESENTS THAT (1) IT IS (A) A "QUALIFIED INSTITUTIONAL BUYER" (AS
          DEFINED IN RULE 144A UNDER THE SECURITIES ACT) OR (B) AN INSTITUTIONAL
          "ACCREDITED INVESTOR" (AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7)
          UNDER THE SECURITIES ACT) ("INSTITUTIONAL ACCREDITED INVESTOR") OR (C)
          NOT A U.S. PERSON AND IS ACQUIRING THE NOTE EVIDENCED HEREBY IN AN
          OFFSHORE TRANSACTION; (2) AGREES THAT IT WILL NOT RESELL OR OTHERWISE
          TRANSFER THE NOTE EVIDENCED HEREBY EXCEPT (A) TO THE COMPANY OR ANY
          SUBSIDIARY THEREOF, (B) TO A QUALIFIED INSTITUTIONAL BUYER IN
          COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (C) TO AN
          INSTITUTIONAL ACCREDITED INVESTOR THAT, PRIOR TO SUCH TRANSFER,
          FURNISHES TO CHASE BANK OF TEXAS, NATIONAL ASSOCIATION, AS TRUSTEE (OR
          A SUCCESSOR TRUSTEE, AS APPLICABLE), A SIGNED LETTER CONTAINING
          CERTAIN REPRESENTATIONS AND AGREEMENTS RELATING TO THE RESTRICTIONS ON
          TRANSFER OF THE NOTE EVIDENCED HEREBY (THE FORM OF WHICH LETTER CAN BE
          OBTAINED FROM SUCH TRUSTEE OR A SUCCESSOR TRUSTEE, AS APPLICABLE), (D)
          OUTSIDE THE UNITED STATES IN COMPLIANCE WITH RULE 904 UNDER THE
          SECURITIES ACT, (E) PURSUANT TO THE EXEMPTION FROM REGISTRATION
          PROVIDED BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR IN
          ACCORDANCE WITH ANOTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS
          OF THE SECURITIES ACT, OR (F) PURSUANT TO AN EFFECTIVE REGISTRATION
          STATEMENT UNDER THE SECURITIES ACT, AND IN EACH CASE, IN ACCORDANCE
          WITH ANY APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES
          OR ANY OTHER APPLICABLE JURISDICTION; AND (3) AGREES THAT IT WILL
          DELIVER TO EACH PERSON TO WHOM THE NOTE

                                    - 27 -
<PAGE>
 
          EVIDENCED HEREBY IS TRANSFERRED A NOTICE SUBSTANTIALLY TO THE EFFECT
          OF THIS LEGEND.  IF THE PROPOSED TRANSFER IS PURSUANT TO CLAUSE (C),
          (D) OR (E) ABOVE, THE HOLDER MUST, PRIOR TO SUCH TRANSFER, FURNISH TO
          CHASE BANK OF TEXAS, NATIONAL ASSOCIATION, AS TRUSTEE (OR A SUCCESSOR
          TRUSTEE, AS APPLICABLE), SUCH CERTIFICATIONS, LEGAL OPINIONS OR OTHER
          INFORMATION AS IT MAY REASONABLY REQUIRE TO CONFIRM THAT SUCH TRANSFER
          IS BEING MADE PURSUANT TO AN EXEMPTION FROM, OR IN A TRANSACTION NOT
          SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT.  AS
          USED HEREIN, THE TERMS "OFFSHORE TRANSACTIONS," "UNITED STATES" AND
          "U.S. PERSON" HAVE THE MEANINGS GIVEN TO THEM BY REGULATION S UNDER
          THE SECURITIES ACT.

          (ii) Upon any sale or transfer of a Transfer Restricted Security
     (including any Transfer Restricted Security represented by a Global Note)
     pursuant to Rule 144 under the Securities Act or pursuant to an effective
     registration statement under the Securities Act:

               (A)  in the case of any Transfer Restricted Security that is a
          Definitive Note, the Registrar shall permit the Holder thereof to
          exchange such Transfer Restricted Security for a Definitive Note that
          does not bear the legend set forth in (i) above and rescind any
          restriction on the transfer of such Transfer Restricted Security upon
          certification from the transferring holder substantially in the form
          of Exhibit B-3 hereto; and

               (B)  in the case of any Transfer Restricted Security represented
          by a Global Note, such Transfer Restricted Security shall not be
          required to bear the legend set forth in (i) above, but shall continue
          to be subject to the provisions of Section 2.06(a) and (c) hereof;
          provided, however, that with respect to any request for an exchange of
          a Transfer Restricted Security that is represented by a Global Note
          for a Definitive Note that does not bear the legend set forth in (i)
          above, which request is made in reliance upon Rule 144 or pursuant to
          an effective registration statement, the Holder thereof shall certify
          in writing to the Registrar that such request is being made pursuant
          to Rule 144 or pursuant to an effective registration statement (such
          certification to be substantially in the form of Exhibit B-4 hereto).

          (iii)     Upon any sale or transfer of a Transfer Restricted Security
     (including any Transfer Restricted Security represented by a Global Note)
     in reliance on any exemption from the registration requirements of the
     Securities Act (other than exemptions pursuant to Rule 144 under the
     Securities Act) in which the Holder or the transferee provides an Opinion
     of Counsel to the Company and the Registrar in form and substance
     reasonably acceptable to the Company and the Registrar (which Opinion of
     Counsel shall also state that the transfer restrictions contained in the
     legend are no longer applicable):

               (A)  in the case of any Transfer Restricted Security that is a
          Definitive Note, the Registrar shall permit the Holder thereof to
          exchange such Transfer Restricted Security for a Definitive Note that
          does not bear the legend set forth in (i) above and rescind any
          restriction on the transfer of such Transfer Restricted Security; and

                                    - 28 -
<PAGE>
 
               (B)  in the case of any Transfer Restricted Security represented
          by a Global Note, such Transfer Restricted Security shall not be
          required to bear the legend set forth in (i) above, but shall continue
          to be subject to the provisions of Section 2.06(a) and (c) hereof.

          (iv) Notwithstanding the foregoing, upon consummation of an Exchange
     Offer, the Company shall issue and, upon receipt of an authentication order
     in accordance with Section 2.02 hereof, the Trustee shall authenticate one
     or more Unrestricted Global Notes in aggregate principal amount equal to
     the sum of (A) the principal amount of the Restricted Beneficial Interests
     tendered for acceptance by Persons that are not (1) broker-dealers, (2)
     Persons participating in the distribution of the Series F Notes or (3)
     Persons who are Affiliates of the Company and accepted for exchange in the
     Exchange Offer and (B) the principal amount of the Restricted Definitive
     Notes accepted for exchange in the Exchange Offer, unless the Holders of
     such Restricted Definitive Notes shall request the receipt of Definitive
     Notes, in which case the Company shall execute and the Trustee shall
     authenticate and deliver to the Persons designated by the Holders of such
     Restricted Definitive Notes one or more Definitive Notes without the legend
     set forth in Section 2.06(f) in the appropriate principal amount.
     Concurrently with the issuance of such Unrestricted Global Notes, the
     Trustee shall cause the aggregate principal amount of the applicable
     Restricted Global Note to be reduced accordingly.

     (g)  Cancellation and/or Adjustment of Global Notes.  At such time as all
beneficial interests in Global Notes have been exchanged for Definitive Notes,
redeemed, repurchased or canceled, all Global Notes shall be returned to or
retained and canceled by the Trustee in accordance with Section 2.11 hereof.  At
any time prior to such cancellation, if any beneficial interest in a Global Note
is exchanged for Definitive Notes, redeemed, repurchased or cancelled, the
principal amount of Notes represented by such Global Note shall be reduced
accordingly and an endorsement shall be made on such Global Note, by the Trustee
or the Note Custodian, at the direction of the Trustee, to reflect such
reduction.

     (h)  General Provisions Relating to Transfers and Exchanges.

          (i)  To permit registrations of transfers and exchanges, subject to
     this Section 2.06, the Company shall execute and, upon the written order of
     the Company signed by one Officer of the Company, the Trustee shall
     authenticate Definitive Notes and Global Notes at the Registrar's request.

          (ii) No service charge shall be made to a Holder for any registration
     of transfer or exchange, but the Company may require payment of a sum
     sufficient to cover any transfer tax or similar governmental charge payable
     in connection therewith (other than any such transfer taxes or similar
     governmental charge payable upon exchange or transfer pursuant to Sections
     3.07, 4.10, 4.15 and 9.05 hereof).

          (iii)     The Registrar shall not be required to register the transfer
     of or exchange any Note selected for redemption in whole or in part, except
     the unredeemed portion of any Note being redeemed in part.

                                    - 29 -
<PAGE>
 
          (iv) All Definitive Notes and Global Notes issued upon any
     registration of transfer or exchange of Definitive Notes or Global Notes
     shall be the valid obligations of the Company, evidencing the same debt,
     and entitled to the same benefits under this Indenture, as the Definitive
     Notes or Global Notes surrendered upon such registration of transfer or
     exchange.

          (v)  The Company and the Registrar shall not be required:

               (A)  to issue, to register the transfer of or to exchange Notes
          during a period beginning at the opening of business 15 days before
          the day of any selection of Notes for redemption under Section 3.02
          hereof and ending at the close of business on the day of selection;

               (B)  to register the transfer of or to exchange any Note so
          selected for redemption in whole or in part, except the unredeemed
          portion of any Note being redeemed in part;

               (C)  to register the transfer of or to exchange a Note between a
          record date and the next succeeding interest payment date; or

               (D)  to register the transfer of a Note other than in amounts of
          $1,000 or multiple integrals thereof.

          (vi) Prior to due presentment for the registration of a transfer of
     any Note, the Trustee, any Agent and the Company may deem and treat the
     Person in whose name any Note is registered as the absolute owner of such
     Note for the purpose of receiving payment of principal of and interest on
     such Notes, and neither the Trustee, any Agent nor the Company shall be
     affected by notice to the contrary.

          (vii)     The Trustee shall authenticate Definitive Notes and Global
     Notes in accordance with the provisions of Section 2.02 hereof.

Section 2.07.  Replacement Notes.

     If any mutilated Note is surrendered to the Trustee or the Company, or the
Trustee receives evidence to its satisfaction of the destruction, loss or theft
of any Note, the Company shall issue and the Trustee, upon the written order of
the Company signed by two Officers of the Company, shall authenticate a
replacement Note if the Trustee's requirements are met.  If required by the
Trustee or the Company, an indemnity bond must be supplied by the Holder that is
sufficient in the judgment of the Trustee and the Company to protect the
Company, the Trustee, any Agent and any authenticating agent from any loss that
any of them may suffer if a Note is replaced.  The Company may charge for its
expenses in replacing a Note.  If, after the delivery of such replacement Note,
a bona fide purchaser of the original Note in lieu of which such replacement
Note was issued presents for payment or registration such original Note, the
Trustee shall be entitled to recover such replacement Note from the Person to
whom it was delivered or any Person taking therefrom, except a bona fide
purchaser, and shall be entitled to recover upon the security or indemnity
provided

                                    - 30 -
<PAGE>
 
therefor to the extent of any loss, damage, cost or expense incurred by the
Company, the Trustee, any Agent and any authenticating agent in connection
therewith.

     Subject to the provisions of the final sentence of the preceding paragraph
of this Section 2.07, every replacement Note is an additional obligation of the
Company and shall be entitled to all of the benefits of this Indenture equally
and proportionately with all other Notes duly issued hereunder.

Section 2.08.  Outstanding Notes.

     The Notes outstanding at any time are all the Notes authenticated by the
Trustee except for those canceled by it, those delivered to it for cancellation,
those reductions in the interest in a Global Note effected by the Trustee in
accordance with the provisions hereof, and those described in this Section as
not outstanding.  Except as set forth in Section 2.09 hereof, a Note does not
cease to be outstanding because the Company, any Subsidiary of the Company or an
Affiliate of the Company or any Subsidiary of the Company holds the Note.

     If a Note is replaced pursuant to Section 2.07 hereof, it ceases to be
outstanding unless the Trustee receives proof satisfactory to it that the
replaced Note is held by a bona fide purchaser.

     If the entire principal of and premium, interest and Liquidated Damages, if
any, on any Note are considered paid under Section 4.01 hereof, it ceases to be
outstanding and interest and Liquidated Damages, if any, on it cease to accrue.

     If the Paying Agent (other than the Company, a Subsidiary of the Company or
an Affiliate of any thereof) holds, on a redemption date or maturity date, money
sufficient to pay Notes payable on that date, then on and after that date such
Notes shall be deemed to be no longer outstanding and shall cease to accrue
interest and Liquidated Damages, if any.

Section 2.09.  Treasury Notes.

     In determining whether the Holders of the required principal amount of
Notes have concurred in any direction, waiver or consent, Notes owned by the
Company, a Subsidiary of the Company or an Affiliate, shall be considered as
though not outstanding, except that for the purposes of determining whether the
Trustee shall be protected in relying on any such direction, waiver or consent,
only Notes that a Trustee knows are so owned shall be so disregarded.
Notwithstanding the foregoing, Notes that the Company, a Subsidiary of the
Company or an Affiliate offers to purchase or acquires pursuant to an offer,
exchange offer, tender offer or otherwise shall not be deemed to be owned by the
Company, a Subsidiary of the Company or an Affiliate until legal title to such
Notes passes to the Company, such Subsidiary or such Affiliate as the case may
be.

Section 2.10.  Temporary Notes.

     Until definitive Notes are ready for delivery, the Company may prepare and
the Trustee shall authenticate temporary Notes upon a written order of the
Company signed by two Officers of the Company. Temporary Notes shall be
substantially in the form of definitive Notes but may have variations that the
Company considers appropriate for temporary Notes and as shall be reasonably

                                    - 31 -
<PAGE>
 
acceptable to the Trustee.  Without unreasonable delay, the Company shall
prepare and the Trustee shall authenticate definitive Notes in exchange for
temporary Notes.  Until such exchange, Holders of temporary Notes shall be
entitled to all of the benefits of this Indenture.

Section 2.11.  Cancellation.

     The Company at any time may deliver Notes to the Trustee for cancellation.
The Registrar and Paying Agent shall forward to the Trustee any Notes
surrendered to them for registration of transfer, exchange or payment.  The
Trustee and no one else shall cancel all Notes surrendered for registration of
transfer, exchange, payment, replacement or cancellation and, at the request of
the Company, shall destroy canceled Notes (subject to the record retention
requirement of the Exchange Act).  Certification of the destruction of all
canceled Notes shall be delivered to the Company.  The Company may not issue new
Notes to replace Notes that it has paid or that have been delivered to the
Trustee for cancellation, other than as contemplated by the Exchange Offer.

Section 2.12.  Defaulted Interest.

     If the Company defaults in a payment of interest on the Notes, it shall pay
the defaulted interest in any lawful manner plus, to the extent lawful, interest
payable on the defaulted interest, to the Persons who are Holders on a
subsequent special record date, in each case at the rate provided in the Notes
and in Section 4.01 hereof.  The Company shall notify the Trustee in writing of
the amount of defaulted interest proposed to be paid on each Note and the date
of the proposed payment. The Company shall fix or cause to be fixed each such
special record date and payment date, provided, however, that no such special
record date shall be less than 10 days prior to the related payment date for
such defaulted interest.  At least 15 days before the special record date, the
Company (or, upon the written request of the Company, the Trustee in the name
and at the expense of the Company) shall mail or cause to be mailed to Holders a
notice that states the special record date, the related payment date and the
amount of such interest to be paid.

                                  ARTICLE 3 
                           REDEMPTION AND PREPAYMENT

Section 3.01.  Notices to Trustee.

     If the Company elects to redeem Notes pursuant to the optional redemption
provisions of Section 3.07 hereof, it shall furnish to the Trustee, at least 30
days but not more than 60 days before a redemption date, an Officers'
Certificate setting forth (i) the clause of this Indenture pursuant to which the
redemption shall occur, (ii) the redemption date, (iii) the principal amount of
Notes to be redeemed and (iv) the redemption price.

Section 3.02.  Selection of Notes to Be Redeemed.

     If less than all of the Notes are to be redeemed at any time, the Trustee
shall select the Notes to be redeemed among the Holders of the Notes, on a pro
rata basis, by lot or in accordance with any other method the Trustee considers
fair and appropriate.  In the event of partial redemption by lot, the particular
Notes to be redeemed shall be selected, unless otherwise provided herein, not
less than

                                    - 32 -
<PAGE>
 
30 days nor more than 60 days prior to the redemption date by the Trustee from
the outstanding Notes not previously called for redemption.

     The Trustee shall promptly notify the Company in writing of the Notes
selected for redemption and, in the case of any Note selected for partial
redemption, the principal amount thereof to be redeemed.  Notes and portions of
Notes selected shall be in amounts of $1,000 or whole multiples of $1,000.
Provisions of this Indenture that apply to Notes called for redemption also
apply to portions of Notes called for redemption.

     The provisions of the two preceding paragraphs of this Section 3.02 shall
not apply with respect to any redemption affecting only a Global Note, whether
such Global Note is to be redeemed in whole or in part.  In case of any such
redemption in part, the unredeemed portion of the principal amount of the Global
Note shall be in an authorized denomination.

Section 3.03.  Notice of Redemption.

     Subject to the provisions of Section 3.09 hereof, at least 30 days but not
more than 60 days before a redemption date, the Company shall mail or cause to
be mailed, by first class mail, a notice of redemption to each Holder whose
Notes are to be redeemed at its registered address.

     The notice shall identify the Notes to be redeemed and shall state:

          (a)  the redemption date;

          (b)  the redemption price;

          (c)  if any Note is being redeemed in part, the portion of the
     principal amount of such Note to be redeemed and that, after the redemption
     date upon surrender of such Note, a new Note or Notes in a principal amount
     equal to the unredeemed portion shall be issued upon cancellation of the
     original Note;

          (d)  the name and address of the Paying Agent;

          (e)  that Notes called for redemption must be surrendered to the
     Paying Agent to collect the redemption price;

          (f)  that, unless the Company defaults in making such redemption
     payment, interest and Liquidated Damages, if any, on Notes called for
     redemption cease to accrue on and after the redemption date;

          (g)  the paragraph of the Notes and/or Section of this Indenture
     pursuant to which the Notes called for redemption are being redeemed; and

          (h)  that no representation is made as to the correctness or accuracy
     of the CUSIP number, if any, listed in such notice or printed on the Notes.

                                    - 33 -
<PAGE>
 
     If any of the Notes to be redeemed is in the form of a Global Note, then
the Company shall modify such notice to the extent necessary to accord with the
procedures of the Depository applicable to redemption.

     At the Company's request, the Trustee shall give the notice of redemption
in the Company's name and at its expense; provided, however, that the Company
shall have delivered to the Trustee, at least 45 days (unless the Company and
the Trustee agree to a shorter period) prior to the redemption date, an
Officers' Certificate requesting that the Trustee give such notice and setting
forth the information to be stated in such notice as provided in the preceding
paragraph.

Section 3.04.  Effect of Notice of Redemption.

     Once notice of redemption is mailed in accordance with Section 3.03 hereof,
Notes called for redemption become irrevocably due and payable on the redemption
date at the redemption price. A notice of redemption may not be conditional.

Section 3.05.  Deposit of Redemption Price.

     At least one Business Day prior to the redemption date, the Company shall
deposit with the Paying Agent (or, if the Company is acting as its own Paying
Agent, segregate and hold in trust as provided in Section 2.04 hereof) money
sufficient to pay the redemption price of and accrued interest and Liquidated
Damages, if any, on all Notes to be redeemed on that date.  The Paying Agent
shall promptly return to the Company any money deposited with the Paying Agent
by the Company in excess of the amounts necessary to pay the redemption price of
and accrued interest and Liquidated Damages, if any, on all Notes to be
redeemed.

     If the Company complies with the provisions of the preceding paragraph, on
and after the redemption date, interest and Liquidated Damages, if any, shall
cease to accrue on the Notes or the portions of Notes called for redemption.  If
a Note is redeemed on or after an interest record date but on or prior to the
related interest payment date, then any accrued and unpaid interest and
Liquidated Damages, if any, shall be paid to the Person in whose name such Note
was registered at the close of business on such record date.  If any Note called
for redemption shall not be so paid upon surrender for redemption because of the
failure of the Company to comply with the preceding paragraph, interest shall be
paid on the unpaid principal, from the redemption date until such principal is
paid, and to the extent lawful on any interest and Liquidated Damages, if any,
not paid on such unpaid principal, in each case at the rate provided in the
Notes and in Section 4.01 hereof.

Section 3.06.  Notes Redeemed in Part.

     Upon surrender of a Note that is redeemed in part, the Company shall issue
and the Trustee shall authenticate for the Holder at the expense of the Company
a new Note equal in principal amount to the unredeemed portion of the Note
surrendered.

                                    - 34 -
<PAGE>
 
Section 3.07.  Optional Redemption.

     (a)  Except as set forth in clause (b) of this Section 3.07, the Company
shall not have the option to redeem the Notes pursuant to this Section 3.07
prior to February 15, 2002.  Thereafter, the Company shall have the option to
redeem the Notes, in whole or in part, at the redemption prices (expressed as
percentages of principal amount) set forth below plus accrued and unpaid
interest and Liquidated Damages, if any, thereon, to the applicable redemption
date, if redeemed during the twelve-month period beginning on February 15 of the
years indicated below:

              Year                                         Percentage

              2002. . . . . . . . . . . . . . . . . .       104.563%
              2003  . . . . . . . . . . . . . . . . .       103.042%
              2004  . . . . . . . . . . . . . . . . .       101.521%
              2005 and thereafter . . . . . . . . . .       100.000%

     (b)  Notwithstanding the provisions of clause (a) of this Section 3.07, the
Company may at any time prior to February 15, 2002, at its option, redeem the
Notes, in whole or in part, at the Make-Whole Price, plus accrued and unpaid
interest and Liquidated Damages, if any, thereon to the redemption date.  In
addition, at any time prior to February 9, 2001, the Company may redeem up to
35% of the aggregate principal amount of Notes originally issued at a redemption
price of 109% of the principal amount thereof, plus accrued and unpaid interest
and Liquidated Damages, if any, thereon to the redemption date, with the net
cash proceeds of one or more Qualified Equity Offerings, provided that (i) at
least 65% of the aggregate principal amount of Notes originally issued remains
outstanding immediately after the occurrence of each such redemption and (ii)
each such redemption shall occur within 60 days of the date of the closing of
each such Qualified Equity Offering.

     (c)  Any redemption pursuant to this Section 3.07 shall be made pursuant to
the provisions of Section 3.01 through Section 3.06 hereof.

Section 3.08.  Mandatory Redemption.

     Except as set forth under Sections 4.10 and 4.15 hereof, the Company shall
not be required to make mandatory redemption or sinking fund payments with
respect to the Notes.

Section 3.09.  Offer to Purchase by Application of Excess Proceeds.

     In the event that, pursuant to Section 4.10 hereof, the Company shall be
required to commence an offer to all Holders to purchase Notes (an "Asset Sale
Offer"), it shall follow the procedures specified below.

     The Asset Sale Offer shall remain open for a period of 20 Business Days
following its commencement and no longer, except to the extent that a longer
period is required by applicable law (the "Offer Period").  No later than five
Business Days after the termination of the Offer Period (the "Purchase Date"),
the Company shall purchase the principal amount of Notes required to be

                                    - 35 -
<PAGE>
 
purchased pursuant to Section 4.10 hereof (the "Offer Amount") or, if less than
the Offer Amount has been tendered, all Notes validly tendered in response to
the Asset Sale Offer.  Payment for any Notes so purchased shall be made in the
same manner as interest payments are made.

     If the Purchase Date is on or after an interest record date and on or
before the related interest payment date, any accrued and unpaid interest and
Liquidated Damages, if any, shall be paid to the Person in whose name a Note is
registered at the close of business on such record date, and no additional
interest or Liquidated Damages, if any, shall be payable to Holders who tender
Notes pursuant to the Asset Sale Offer.

     Upon the commencement of an Asset Sale Offer, the Company shall send, by
first class mail, a notice to each of the Holders, with a copy to the Trustee.
The notice shall contain all instructions and materials necessary to enable such
Holders to tender Notes pursuant to the Asset Sale Offer. The Asset Sale Offer
shall be made to all Holders.  The notice, which shall govern the terms of the
Asset Sale Offer, shall state:

          (a)  that the Asset Sale Offer is being made pursuant to this Section
     3.09 and Section 4.10 hereof and the length of time the Asset Sale Offer
     shall remain open;

          (b)  the Offer Amount, the purchase price and the Purchase Date;

          (c)  that any Note not tendered or accepted for payment shall continue
     to accrue interest and Liquidated Damages, if any;

          (d)  that, unless the Company defaults in making such payment, any
     Note accepted for payment pursuant to the Asset Sale Offer shall cease to
     accrue interest and Liquidated Damages, if any after the Purchase Date;

          (e)  that Holders electing to have a Note purchased pursuant to an
     Asset Sale Offer may only elect to have all of such Note purchased and may
     not elect to have only a portion of such Note purchased;

          (f)  that Holders electing to have a Note purchased pursuant to any
     Asset Sale Offer shall be required to surrender the Note, with the form
     entitled "Option of Holder to Elect Purchase" on the reverse of the Note
     completed, to the Company or a Paying Agent at the address specified in the
     notice at least three days before the Purchase Date;

          (g)  that Holders shall be entitled to withdraw their election if the
     Company or the Paying Agent, as the case may be, receives, not later than
     the expiration of the Offer Period, a telegram, telex, facsimile
     transmission or letter setting forth the name of the Holder, the principal
     amount of the Note the Holder delivered for purchase and a statement that
     such Holder is withdrawing his election to have such Note purchased;

          (h)  that, if the aggregate principal amount of Notes surrendered by
     Holders exceeds the Offer Amount, the Trustee shall select the Notes to be
     purchased on a pro rata

                                    - 36 -
<PAGE>
 
     basis (with such adjustments as may be deemed appropriate by the Trustee so
     that only Notes in denominations of $1,000, or integral multiples thereof,
     shall be purchased); and

          (i)  that Holders whose Notes were purchased only in part shall be
     issued new Notes equal in principal amount to the unpurchased portion of
     the Notes surrendered (or transferred by book-entry transfer).

     If any of the Notes subject to an Asset Sale Offer is in the form of a
Global Note, then the Company shall modify such notice to the extent necessary
to accord with the procedures of the Depository applicable to repurchases.

     On or before the Purchase Date, the Company shall, to the extent lawful,
accept for payment, on a pro rata basis to the extent necessary, the Offer
Amount of Notes or portions thereof tendered pursuant to the Asset Sale Offer,
or if less than the Offer Amount has been tendered, all Notes tendered, and
shall deliver to the Trustee an Officers' Certificate stating that such Notes or
portions thereof were accepted for payment by the Company in accordance with the
terms of this Section 3.09.  The Company or the Paying Agent, as the case may
be, shall promptly (but in any case not later than five days after the Purchase
Date) mail or deliver to each tendering Holder an amount equal to the purchase
price of the Notes tendered by such Holder and accepted by the Company for
purchase, and the Company shall promptly issue a new Note, and the Trustee shall
authenticate and mail or deliver such new Note to such Holder, in a principal
amount equal to any unpurchased portion of the Note surrendered.  Any Note not
so accepted shall be promptly mailed or delivered by the Company to the Holder
thereof.  The Company shall publicly announce the results of the Asset Sale
Offer on the Purchase Date.

     Other than as specifically provided in this Section 3.09, any purchase
pursuant to this Section 3.09 shall be made pursuant to the provisions of
Section 3.01 through Section 3.06 hereof.

                                   ARTICLE 4
                                   COVENANTS

Section 4.01.  Payment of Notes.

     The Company shall pay or cause to be paid the principal of and premium,
interest and Liquidated Damages, if any, on the Notes on the dates and in the
manner provided in the Notes. Principal, premium, interest and Liquidated
Damages, if any, shall be considered paid on the date due if the Paying Agent,
if other than the Company or a Subsidiary thereof, holds as of 10:00 a.m. New
York time on the due date money deposited by the Company in immediately
available funds and designated for and sufficient to pay all principal, premium,
interest and Liquidated Damages, if any, then due.

     The Company shall pay interest (including post-petition interest in any
proceeding under any Bankruptcy Law) on overdue principal at the rate equal to
the interest rate on the Notes to the extent lawful; it shall pay interest
(including post-petition interest in any proceeding under any Bankruptcy Law) on
overdue installments of interest and Liquidated Damages, if any (without regard
to any applicable grace period), at the same rate to the extent lawful.

                                    - 37 -
<PAGE>
 
Section 4.02.  Maintenance of Office or Agency.

     The Company shall maintain an office or agency (which may be an office of
the Trustee or an affiliate of the Trustee, Registrar or co-registrar) where
Notes may be presented or surrendered for payment, where Notes may be
surrendered for registration of transfer or for exchange and where notices and
demands to or upon the Company in respect of the Notes and this Indenture may be
served.  The Company shall 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.

     The Company may also from time to time designate one or more other offices
or agencies where the Notes may be presented or surrendered for any or all such
purposes and may from time to time rescind such designations.  Further, if at
any time there shall be no such office or agency in the City of New York where
the Notes may be presented or surrendered for payment, the Company shall
forthwith designate and maintain such an office or agency in the City of New
York, in order that the Notes shall at all times be payable in the City of New
York.  The Company shall 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.

     The Company hereby designates the Corporate Trust Office of the Trustee as
one such office or agency of the Company in accordance with Section 2.03.

Section 4.03.  Reports.

     (a)  Whether or not the Company is required to do so by the rules and
regulations of the SEC, the Company will file with the SEC (unless the SEC will
not accept such a filing) and, within 15 days of filing, or attempting to file,
the same with the SEC, furnish to the holders of the Notes (i) all quarterly and
annual financial and other information with respect to the Company and its
Subsidiaries that would be required to be contained in a filing with the SEC on
Forms 10-Q and 10-K if the Company were required to file such forms, including a
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" and, with respect to the annual information only, a report thereon
by the Company's certified independent accountants, and (ii) all current reports
that would be required to be filed with the SEC on Form 8-K if the Company were
required to file such reports.  The Company shall at all times comply with 
TIA (S) 314(a).

     (b)  The Company and the Guarantors shall furnish to the holders of the
Notes, prospective purchasers of the Notes and securities analysts, upon their
request, the information, if any, required to be delivered pursuant to Rule
144A(d)(4) under the Securities Act.

Section 4.04.  Compliance Certificate.

     (a)  The Company shall deliver to the Trustee, within 90 days after the end
of each fiscal year, an Officers' Certificate stating that a review of the
activities of the Company and its Restricted Subsidiaries during the preceding
fiscal year has been made under the supervision of the signing

                                    - 38 -
<PAGE>
 
Officers with a view to determining whether the Company has kept, observed,
performed and fulfilled its obligations under this Indenture, and further
stating, as to each such Officer signing such certificate, that to the best of
his or her knowledge the Company has kept, observed, performed and fulfilled
each and every covenant contained in this Indenture and is not in default in the
performance or observance of any of the terms, provisions and conditions of this
Indenture (or, if a Default or Event of Default shall have occurred, describing
all such Defaults or Events of Default of which he or she may have knowledge and
what action the Company is taking or proposes to take with respect thereto) and
that to the best of his or her knowledge no event has occurred and remains in
existence by reason of which payments on account of the principal of or
interest, if any, on the Notes is prohibited or if such event has occurred, a
description of the event and what action the Company is taking or proposes to
take with respect thereto.

     (b)  So long as not contrary to the then current recommendations of the
American Institute of Certified Public Accountants, the year-end financial
statements delivered pursuant to Section 4.03(a) above shall be accompanied by a
written statement of the Company's independent public accountants (who shall be
a firm of established national reputation) that in making the examination
necessary for certification of such financial statements, nothing has come to
their attention that would lead them to believe that the Company has violated
any provisions of Article 4 or Article 5 hereof or, if any such violation has
occurred, specifying the nature and period of existence thereof, it being
understood that such accountants shall not be liable directly or indirectly to
any Person for any failure to obtain knowledge of any such violation.

     (c)  The Company shall, so long as any of the Notes are outstanding,
deliver to the Trustee, forthwith upon any Officer becoming aware of any Default
or Event of Default, an Officers' Certificate specifying such Default or Event
of Default and what action the Company is taking or proposes to take with
respect thereto.

Section 4.05.  Taxes.

     The Company shall pay, and shall cause each of its Subsidiaries to pay,
prior to delinquency, all material taxes, assessments, and governmental levies
except such as are contested in good faith and by appropriate proceedings or
where the failure to effect such payment is not adverse in any material respect
to the Holders of the Notes.

Section 4.06.  Stay, Extension and Usury Laws.

     The Company covenants (to the extent that it may lawfully do so) that it
shall not at any time insist upon, plead, or in any manner whatsoever claim or
take the benefit or advantage of, any stay, extension or usury law wherever
enacted, now or at any time hereafter in force, that 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 shall not, by resort to any such law, hinder, delay
or impede the execution of any power herein granted to the Trustee, but shall
suffer and permit the execution of every such power as though no such law has
been enacted.

                                    - 39 -
<PAGE>
 
Section 4.07.  Restricted Payments.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, directly or indirectly, (i) declare or pay any dividend or make
any other payment or distribution on account of the Company's or any of its
Restricted Subsidiaries' Equity Interests (including, without limitation, any
such payment in connection with any merger or consolidation involving the
Company) or to the direct or indirect holders of the Company's Equity Interests
in their capacity as such (other than dividends or distributions payable in
Equity Interests (other than Disqualified Stock) of the Company); (ii) purchase,
redeem or otherwise acquire or retire for value (including without limitation,
in connection with any merger or consolidation involving the Company) any Equity
Interests of the Company (other than any such Equity Interests owned by the
Company or any Restricted Subsidiary of the Company); (iii) make any payment on
or with respect to, or purchase, redeem, defease or otherwise acquire or retire
for value, any Indebtedness that is subordinated to the Notes, except a payment
of interest or principal at Stated Maturity (or within one year thereof); or
(iv) make any Restricted Investment (all such payments and other actions set
forth in clauses (i) through (iv) above being collectively referred to as
"Restricted Payments"), unless, at the time of and after giving effect to such
Restricted Payment:

          (a)  no Default or Event of Default shall have occurred and be
     continuing or would occur as a consequence thereof;

          (b)  the Company would, at the time of such Restricted Payment and
     after giving pro forma effect thereto as if such Restricted Payment had
     been made at the beginning of the applicable four-quarter period, have been
     permitted to incur at least $1.00 of additional Indebtedness pursuant to
     the Consolidated Interest Coverage Ratio test set forth in Section 4.09
     hereof; and

          (c)  such Restricted Payment, together with the aggregate amount of
     all other Restricted Payments made by the Company and its Restricted
     Subsidiaries after the Issue Date (excluding Restricted Payments permitted
     by clauses (b), (c), (d) and (f), but including, without duplication,
     Restricted Payments permitted by clauses (a) and (e), of the next
     succeeding paragraph), is less than the sum of (A) 50% of the Consolidated
     Net Income of the Company for the period (taken as one accounting period)
     from January 1, 1998 to the end of the Company's most recently ended fiscal
     quarter for which internal financial statements are available at the time
     of such Restricted Payment (or, if such Consolidated Net Income for such
     period is a deficit, less 100% of such deficit), plus (B) 100% of the
     aggregate net cash proceeds received by the Company from the issue or sale
     since the Issue Date of Equity Interests of the Company (other than
     Disqualified Stock) or of Disqualified Stock or debt securities of the
     Company that have been converted into such Equity Interests (other than any
     such Equity Interests, Disqualified Stock or convertible debt securities
     sold to a Restricted Subsidiary of the Company and other than Disqualified
     Stock or convertible debt securities that have been converted into
     Disqualified Stock), plus (C) the aggregate principal amount of any
     Convertible Debentures converted into Equity Interests since the Issue
     Date, plus (D) to the extent that any Restricted Investment that was made
     after the Issue Date is or was sold for cash or otherwise liquidated or
     repaid for cash, the cash return of capital with respect to such Restricted
     Investment (less the cost of disposition, if any), plus (E) in the event
     that

                                    - 40 -
<PAGE>
 
     any Unrestricted Subsidiary is redesignated as a Restricted Subsidiary, the
     lesser of (1) an amount equal to the fair value of the Company's
     Investments in such Restricted Subsidiary and (2) the amount of Restricted
     Investments previously made by the Company and its Restricted Subsidiaries
     in such Unrestricted Subsidiary, plus (F) $10.0 million.

     The foregoing provisions will not prohibit any of the following:  (a) the
payment of any dividend within 60 days after the date of declaration thereof, if
at said date of declaration such payment would have complied with the provisions
of this Indenture; (b) the redemption, repurchase, retirement, defeasance or
other acquisition of any subordinated Indebtedness or Equity Interests of the
Company in exchange for, or out of the net cash proceeds of the substantially
concurrent sale (other than to a Subsidiary of the Company) of, other Equity
Interests of the Company (other than any Disqualified Stock), provided that the
amount of any such net cash proceeds that are utilized for any such redemption,
repurchase, retirement, defeasance or other acquisition shall be excluded from
clause (iii)(B) of the preceding paragraph; (c) the defeasance, redemption,
repurchase, retirement or other acquisition of subordinated Indebtedness with
the net cash proceeds from an incurrence of, or in exchange for, Permitted
Refinancing Indebtedness; (d) the payment of any dividend or distribution by a
Restricted Subsidiary of the Company to the holders of its common Equity
Interests on a pro rata basis; (e) so long as no Default or Event of Default
shall have occurred and be continuing, the repurchase, redemption or other
acquisition or retirement for value of any Equity Interests of the Company held
by any employee of the Company's or any of its Restricted Subsidiaries, provided
that the aggregate price paid for all such repurchased, redeemed, acquired or
retired Equity Interests shall not exceed $1.0 million in any calendar year; and
(f) the acquisition of Equity Interests of the Company in connection with the
exercise of stock options or stock appreciation rights by way of cashless
exercise or in connection with the satisfaction of withholding tax obligations.

     The Board of Directors may designate any Restricted Subsidiary to be an
Unrestricted Subsidiary if such designation would not cause a Default.  For
purposes of making such determination, all outstanding Investments by the
Company and its Restricted Subsidiaries (except to the extent repaid in cash) in
the Subsidiary so designated shall be deemed to be Restricted Payments at the
time of such designation. All such outstanding Investments will be deemed to
constitute Investments in an amount equal to the greater of (a) the net book
value of such Investments at the time of such designation and (b) the fair
market value of such Investments at the time of such designation. Such
designation shall only be permitted if such Restricted Payment would be
permitted at such time and if such Restricted Subsidiary otherwise meets the
definition of an Unrestricted Subsidiary.

     The Board of Directors of the Company may at any time designate any
Unrestricted Subsidiary to be a Restricted Subsidiary, provided that such
designation shall be deemed to be an incurrence of Indebtedness by a Restricted
Subsidiary of the Company of any outstanding Indebtedness of such Unrestricted
Subsidiary and such designation shall only be permitted if (a) such Indebtedness
is permitted under Section 4.09 hereof, calculated on a pro forma basis as if
such designation had occurred at the beginning of the four-quarter reference
period, and (b) no Default or Event of Default would be in existence following
such designation.

     Any designation of a Subsidiary as an Unrestricted Subsidiary shall be
evidenced to the Trustee by filing with the Trustee a certified copy of a
resolution of the Board of Directors giving

                                    - 41 -
<PAGE>
 
effect to such designation and an Officers' Certificate certifying that such
designation complied with the terms of the definition of Unrestricted Subsidiary
set forth in this Indenture and with this Section 4.07.

     The amount of all Restricted Payments (other than cash) shall be the fair
market value on the date of the Restricted Payment of the asset(s) or securities
proposed to be transferred or issued by the Company or such Restricted
Subsidiary, as the case may be, pursuant to the Restricted Payment. The fair
market value of any non-cash Restricted Payment shall be determined in the
manner contemplated by the definition of the term "fair market value," and the
results of such determination shall be evidenced by an Officers' Certificate
delivered to the Trustee.  Not later than the date of making any Restricted
Payment, the Company shall deliver to the Trustee an Officers' Certificate
stating that such Restricted Payment is permitted and setting forth the basis
upon which the calculations required by this Section 4.07 were computed;
provided, however, with respect to any planned purchase or redemption by the
Company of its Equity Interests, the Company may, in advance of any such
purchase or redemption, deliver to the Trustee a single Officers' Certificate
that otherwise complies with requirements set forth above stating (i) the
maximum aggregate amount of Equity Interests to be purchased or redeemed and
(ii) the period over which such purchases or redemptions will occur.

Section 4.08.  Dividend and Other Payment Restrictions Affecting Subsidiaries.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, directly or indirectly, create or otherwise cause or suffer to
exist or become effective any encumbrance or restriction on the ability of any
Restricted Subsidiary to (a)(i) pay dividends or make any other distributions to
the Company or any of its Restricted Subsidiaries on its Capital Stock or with
respect to any other interest or participation in, or measured by, its profits,
or (ii) pay any Indebtedness owed to the Company or any of its Restricted
Subsidiaries, (b) make loans or advances to the Company or any of its Restricted
Subsidiaries or (c) transfer any of its properties or assets to the Company or
any of its Restricted Subsidiaries, except for such encumbrances or restrictions
existing under or by reason of (1) the Credit Facility or Existing Indebtedness,
each as in effect on the Issue Date, (2) this Indenture, the Notes and the
Subsidiary Guarantees, if any, (3) applicable law, (4) any instrument governing
Indebtedness or Capital Stock of a Person acquired by the Company or any of its
Restricted Subsidiaries as in effect at the time of such acquisition (except to
the extent such Indebtedness was incurred in connection with or in contemplation
of such acquisition), which encumbrance or restriction is not applicable to any
Person, or the properties or assets of any Person, other than the Person, or the
property or assets of the Person, so acquired, provided that, in the case of
Indebtedness, such Indebtedness was permitted by the terms of this Indenture to
be incurred, (5) by reason of customary non-assignment provisions in leases
entered into in the ordinary course of business and consistent with past
practices, (6) purchase money obligations for property acquired in the ordinary
course of business that impose restrictions of the nature described in clause
(c) above on the property so acquired, (7) customary provisions in bona fide
contracts for the sale of property or assets or (8) Permitted Refinancing
Indebtedness with respect to any Indebtedness referred to in clauses (1) and (2)
above, provided that the restrictions contained in the agreements governing such
Permitted Refinancing Indebtedness are not materially more restrictive, taken as
a whole, than those contained in the agreements governing the Indebtedness being
refinanced.

                                    - 42 -
<PAGE>
 
Section 4.09.  Incurrence of Indebtedness and Issuance of Disqualified Stock.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, directly or indirectly, create, incur, issue, assume, guarantee
or otherwise become directly or indirectly liable, contingently or otherwise,
with respect to (collectively, "incur" or an "incurrence") any Indebtedness
other than Permitted Indebtedness and that the Company will not issue any
Disqualified Stock and will not permit any of its Restricted Subsidiaries to
issue any shares of Disqualified  Stock; provided, however, that the Company or
a Guarantor may incur Indebtedness, and the Company may issue Disqualified
Stock, if the Consolidated Interest Coverage Ratio for the Company's most
recently ended four full fiscal quarters for which internal financial statements
are available immediately preceding the date on which such additional
Indebtedness is incurred or such Disqualified Stock is issued would have been at
least 2.0 to 1, determined on a pro forma basis (including a pro forma
application of the net proceeds therefrom), as if the additional Indebtedness or
Disqualified Stock had been issued or incurred at the beginning of such
four-quarter period.

Section 4.10.  Asset Sales.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, consummate an Asset Sale unless (a) the Company or such
Restricted Subsidiary, as the case may be, receives consideration at the time of
such Asset Sale at least equal to the fair market value (as determined in
accordance with the definition of such term, the results of which determination
shall be set forth in an Officers' Certificate delivered to the Trustee) of the
assets or Equity Interests issued or sold or otherwise disposed of and (b) at
least 75% of the consideration therefor received by the Company or such
Restricted Subsidiary is in the form of cash or Cash Equivalents; provided,
however, that the amount of (i) any liabilities (as shown on the Company's or
such Restricted Subsidiary's most recent balance sheet) of the Company or such
Restricted Subsidiary (other than contingent liabilities and liabilities that
are by their terms subordinated to the Notes or any guarantee thereof) that are
assumed by the transferee of any such assets pursuant to a customary novation
agreement that releases the Company or such Restricted Subsidiary from further
liability and (ii) any securities, notes or other obligations received by the
Company or such Restricted Subsidiary from such transferee that are immediately
converted by the Company or such Restricted Subsidiary into cash (to the extent
of the cash received) shall be deemed to be cash for purposes of this Section
4.10.

     Within 365 days after the receipt of any Net Proceeds from an Asset Sale,
the Company or any such Restricted Subsidiary may apply such Net Proceeds to (a)
permanently repay the principal of any secured Indebtedness (to the extent of
the fair value of the assets securing such Indebtedness, as determined by the
Board of Directors) or (b) to acquire (including by way of a purchase of assets
or stock, merger, consolidation or otherwise) assets used in the Principal
Business.  (Any such Net Proceeds that are applied to the acquisition of assets
used in the Principal Business pursuant to any binding agreement shall be deemed
to have been applied for such purpose within such 365-day period so long as they
are so applied within two years after the date of receipt of such Net Proceeds.)
Pending the final application of any such Net Proceeds, the Company or any such
Restricted Subsidiary may temporarily reduce outstanding revolving credit
borrowings, or otherwise invest such Net Proceeds in any manner that is not
prohibited by this Indenture. Any Net Proceeds from Asset Sales that are not
applied or invested as provided in the first sentence of this paragraph shall be
deemed to constitute "Excess Proceeds."  Within 30 days of each date on which
the aggregate

                                    - 43 -
<PAGE>
 
amount of Excess Proceeds exceeds $10.0 million, the Company shall commence a
Asset Sale Offer pursuant to Section 3.09 hereof to purchase the maximum
principal amount of Notes that may be purchased out of Excess Proceeds at an
offer price in cash in an amount equal to 100% of the principal amount thereof,
plus accrued and unpaid interest and Liquidated Damages, if any, thereon, to the
date of purchase, in accordance with the procedures set forth in Section 3.09
hereof; provided, however, that, if the Company is required to apply such Excess
Proceeds to repurchase, or to offer to repurchase, any Pari Passu Indebtedness,
the Company shall only be required to offer to repurchase the maximum principal
amount of Notes that may be purchased out of the amount of such Excess Proceeds
multiplied by a fraction, the numerator of which is the aggregate principal
amount of Notes outstanding and the denominator of which is the aggregate
principal amount of Notes outstanding plus the aggregate principal amount of
Pari Passu Indebtedness outstanding. To the extent that the aggregate principal
amount of Notes tendered pursuant to an Asset Sale Offer is less than the amount
that the Company is required to repurchase, the Company may use any remaining
Excess Proceeds for general corporate purposes. If the aggregate principal
amount of Notes surrendered by holders thereof exceeds the amount that the
Company is required to repurchase, the Trustee shall select the Notes to be
purchased on a pro rata basis (with such adjustments as may be deemed
appropriate by the Trustee so that only Notes in denominations of $1,000, or
integral multiples thereof, shall be purchased).  Upon completion of such offer
to purchase, the amount of Excess Proceeds shall be reset at zero.

Section 4.11.  Transactions with Affiliates.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, make any payment to, or sell, lease, transfer or otherwise
dispose of any of its properties or assets to, or purchase any property or
assets from, or enter into or make or amend any transaction, contract,
agreement, understanding, loan, advance or guarantee with, or for the benefit
of, any Affiliate (each of the foregoing, an "Affiliate Transaction"), unless
(a) such Affiliate Transaction is on terms that are no less favorable to the
Company or the relevant Restricted Subsidiary than those that would have been
obtained in a comparable transaction by the Company or such Restricted
Subsidiary with an unrelated Person or, if there is no such comparable
transaction, on terms that are fair and reasonable to the Company or such
Restricted Subsidiary, and (b) the Company delivers to the Trustee (i) with
respect to any Affiliate Transaction or series of related Affiliate Transactions
involving aggregate consideration in excess of $5.0 million, a resolution of the
Board of Directors set forth in an Officers' Certificate certifying that such
Affiliate Transaction complies with clause (a) above and that such Affiliate
Transaction has been approved by a majority of the disinterested members of the
Board of Directors and (ii) with respect to any Affiliate Transaction or series
of related Affiliate Transactions involving aggregate consideration in excess of
$10.0 million, an opinion as to the fairness to the Company or the relevant
Subsidiary of such Affiliate Transaction from a financial point of view issued
by an accounting, appraisal or investment banking firm that is, in the judgment
of the Board of Directors, qualified to render such opinion and is independent
with respect to the Company; provided, however, that the following shall be
deemed not to be Affiliate Transactions:  (A) any employment agreement or other
employee compensation plan or arrangement entered into by the Company or any of
its Restricted Subsidiaries in the ordinary course of business of the Company or
such Restricted Subsidiary; (B) transactions between or among the Company and
its Restricted Subsidiaries; (C) Permitted Investments and Restricted Payments
that are permitted by the provisions of this Indenture; (D) loans or advances to
officers, directors and employees of the

                                    - 44 -
<PAGE>
 
Company or any Restricted Subsidiary made in the ordinary course of business and
consistent with past practices of the Company and its Restricted Subsidiaries in
an aggregate amount not to exceed $500,000 outstanding at any one time; (E)
indemnities of officers, directors and employees of the Company or any
Restricted Subsidiary permitted by bylaw or statutory provisions; and (F) the
payment of reasonable and customary regular fees to directors of the Company or
any of its Restricted Subsidiaries.

Section 4.12.  Liens.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, directly or indirectly, create, incur, assume or suffer to
exist any Lien on any asset now owned or hereafter acquired, or any income or
profits therefrom or assign or convey any right to receive income therefrom,
except Permitted Liens, to secure (a) any Indebtedness of the Company or such
Restricted Subsidiary (if it is not also a Guarantor), unless prior to, or
contemporaneously therewith, the Notes are equally and ratably secured, or (b)
any Indebtedness of any Guarantor, unless prior to, or contemporaneously
therewith, the Subsidiary Guarantees are equally and ratably secured; provided,
however, that if such Indebtedness is expressly subordinated to the Notes or the
Subsidiary Guarantees, the Lien securing such Indebtedness will be subordinated
and junior to the Lien securing the Notes or the Subsidiary Guarantees, as the
case may be, with the same relative priority as such Indebtedness has with
respect to the Notes or the Subsidiary Guarantees.

Section 4.13.  Future Subsidiary Guarantees.

1.        The Company shall cause each Restricted Subsidiary that (i) incurs
     Indebtedness (other than Permitted Indebtedness and Purchase Money
     Indebtedness) following the Issue Date or (ii) has Indebtedness (other than
     Permitted Indebtedness and Purchase Money Indebtedness) or Disqualified
     Stock outstanding on the date on which such Restricted Subsidiary becomes a
     Restricted Subsidiary, to execute a Subsidiary Guarantee at the time such
     Restricted Subsidiary incurs such Indebtedness or becomes a Restricted
     Subsidiary and deliver an Opinion of Counsel and an Officers' Certificate
     in accordance with the terms of Section 10.02 of this Indenture.

Section 4.14.  Corporate Existence.

     Subject to Article 5 hereof, the Company shall do or cause to be done all
things necessary to preserve and keep in full force and effect its corporate
existence, and, subject to Article 10 hereof, the corporate, partnership or
other existence of each of its Restricted Subsidiaries, in accordance with the
respective organizational documents (as the same may be amended from time to
time) of the Company or any such Restricted Subsidiary; provided, however, that
the Company shall not be required to preserve the existence of any of its
Restricted Subsidiaries, 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 its Restricted Subsidiaries, taken as a whole.

                                    - 45 -
<PAGE>
 
Section 4.15.  Offer to Repurchase Upon Change of Control.

     (a)  Upon the occurrence of a Change of Control, the Company shall make an
offer (a "Change of Control Offer") to repurchase all or any part (equal to
$1,000 or an integral multiple thereof) of each Holder's Notes at an offer price
in cash equal to 101% of the aggregate principal amount thereof, plus accrued
and unpaid interest and Liquidated Damages, if any, thereon to the date of
repurchase (the "Change of Control Payment").  Within 30 days following a Change
of Control, the Company shall mail a notice to each Holder and the Trustee
stating: (1) that the Change of Control Offer is being made pursuant to this
Section 4.15 and that all Notes validly tendered and not withdrawn will be
accepted for payment; (2) the purchase price and the purchase date, which shall
be no earlier than 30 days but no later than 60 days from the date such notice
is mailed (the "Change of Control Payment Date"); (3) that any Note not tendered
will continue to accrue interest and Liquidated Damages, if any; (4) that,
unless the Company defaults in the payment of the Change of Control Payment, all
Notes accepted for payment pursuant to the Change of Control Offer shall cease
to accrue interest and Liquidated Damages, if any, after the Change of Control
Payment Date; (5) that Holders electing to have any Notes purchased pursuant to
a Change of Control Offer will be required to surrender the Notes, properly
endorsed for transfer, together with the form entitled "Option of Holder to
Elect Purchase" on the reverse of the Notes completed and such customary
documents as the Company may reasonably request, to the Paying Agent at the
address specified in the notice prior to the close of business on the third
Business Day preceding the Change of Control Payment Date; (6) that Holders will
be entitled to withdraw their election if the Paying Agent receives, not later
than the close of business on the second Business Day preceding the Change of
Control Payment Date, a telegram, telex, facsimile transmission or letter
setting forth the name of the Holder, the principal amount of Notes delivered
for purchase, and a statement that such Holder is withdrawing his election to
have the Notes purchased; and (7) that Holders whose Notes are being purchased
only in part will be issued new Notes equal in principal amount to the
unpurchased portion of the Notes surrendered, which unpurchased portion must be
equal to $1,000 in principal amount or an integral multiple thereof.  If any of
the Notes subject to a Change of Control Offer is in the form of a Global Note,
then the Company shall modify such notice to the extent necessary to accord with
the procedures of the Depository applicable to repurchases.  Further, the
Company shall comply with the requirements of Rule 14e-1 under the Exchange Act
and any other securities laws and regulations thereunder to the extent such laws
and regulations are applicable in connection with the repurchase of Notes as a
result of a Change of Control.

     (b)  On or before 10:00 a.m. New York time on the Change of Control Payment
Date, the Company shall, to the extent lawful, (a) accept for payment all Notes
or portions thereof properly tendered pursuant to the Change of Control Offer,
(b) deposit with the Paying Agent an amount equal to the Change of Control
Payment in respect of all Notes or portions thereof so tendered and (c) deliver
or cause to be delivered to the Trustee the Notes so accepted together with an
Officers' Certificate stating the aggregate principal amount of Notes or
portions thereof being purchased by the Company. The Paying Agent shall promptly
mail to each holder of Notes so tendered the Change of Control Payment for such
Notes, and the Trustee shall promptly authenticate and mail (or cause to be
transferred by book entry) to each Holder a new Note equal in principal amount
to any unpurchased portion of the Notes surrendered, if any; provided, however,
that each such new Note will be in a principal amount of $1,000 or an integral
multiple thereof. The Company shall publicly

                                    - 46 -
<PAGE>
 
announce the results of the Change of Control Offer on or as soon as practicable
after the Change of Control Payment Date.

     (c)  The Change of Control provisions described above shall be applicable
whether or nor any other provisions of this Indenture are applicable.

     (d)  The Company shall not be required to make a Change of Control Offer
following a Change of Control if a third party makes the Change of Control
Offer in the manner, at the time and otherwise in compliance with the
requirements set forth in this Indenture applicable to a Change of Control Offer
made by the Company and purchases all Notes validly tendered and not withdrawn
under such Change of Control Offer.

Section 4.16.  Issuances and Sales of Capital Stock of Wholly Owned Restricted
               Subsidiaries.

     The Company (i) shall not, and shall not permit any Wholly Owned Restricted
Subsidiary of the Company to, transfer, convey, sell, or otherwise dispose of
any Capital Stock of any Wholly Owned Restricted Subsidiary of the Company to
any Person (other than the Company or a Wholly Owned Restricted Subsidiary of
the Company), unless (a) such transfer, conveyance, sale, or other disposition
is of all the Capital Stock of such Wholly Owned Restricted Subsidiary and (b)
the Net Proceeds from such transfer, conveyance, sale, or other disposition are
applied in accordance with Section 4.10 hereof, and (ii) shall not permit any
Wholly Owned Restricted Subsidiary of the Company to issue any of its Equity
Interests to any Person other than to the Company or a Wholly Owned Restricted
Subsidiary of the Company; except, in the case of both clauses (i) and (ii)
above, with respect to dispositions or issuances by a Wholly Owned Restricted
Subsidiary of the Company as contemplated in clauses (a) and (b) of the
definition of "Wholly Owned Restricted Subsidiary."

Section 4.17.  Sale-and-leaseback Transactions.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, enter into any sale-and-leaseback transaction; provided,
however, that the Company or any Restricted Subsidiary, as applicable, may enter
into a sale-and-leaseback transaction if (i) the Company or such Restricted
Subsidiary could have (a) incurred Indebtedness in an amount equal to the
Attributable Indebtedness relating to such sale-and-leaseback transaction
pursuant to the Consolidated Interest Coverage Ratio test set forth in the first
paragraph of Section 4.09 hereof and (b) incurred a Lien to secure such
Indebtedness pursuant to Section 4.12 hereof, (ii) the gross cash proceeds of
such sale-and-leaseback transaction are at least equal to the fair market value
(as determined in accordance with the definition of such term, the results of
which determination shall be set forth in an Officers' Certificate delivered to
the Trustee) of the property that is the subject of such sale-and-leaseback
transaction and (iii) the transfer of assets in such sale-and-leaseback
transaction is permitted by, and the Company applies the proceeds of such
transaction in compliance with, Section 4.10 hereof.

Section 4.18.  No Inducements.

     The Company shall not, and the Company shall not permit any of its
Subsidiaries, either directly or indirectly, to pay (or cause to be paid) any
consideration, whether by way of interest, fee

                                    - 47 -
<PAGE>
 
or otherwise, to any Holder for or as an inducement to any consent, waiver,
amendment or supplement of any terms or provisions of this Indenture or the
Notes, unless such consideration is offered to be paid (or agreed to be paid) to
all Holders which so consent, waive or agree to amend or supplement in the time
frame set forth on solicitation documents relating to such consent, waiver or
agreement.

Section 4.19.  Line of Business.

     The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, engage in any business or activity other than the Principal
Business.

                                   ARTICLE 5
                                  SUCCESSORS

Section 5.01.  Merger, Consolidation, or Sale of Assets.

     The Company shall not consolidate or merge with or into (whether or not the
Company is the surviving corporation), or sell, assign, transfer, lease, convey
or otherwise dispose of all or substantially all of its properties or assets in
one or more related transactions, to another Person unless (a) the Company is
the surviving corporation or the Person formed by or surviving any such
consolidation or merger (if other than the Company) or to which such sale,
assignment, transfer, lease, conveyance or other disposition shall have been
made is a corporation organized or existing under the laws of the United States,
any state thereof or the District of Columbia, (b) the Person formed by or
surviving any such consolidation or merger (if other than the Company) or the
Person to which such sale, assignment, transfer, lease, conveyance or other
disposition shall have been made assumes all the obligations of the Company
under the Notes and this Indenture pursuant to a supplemental indenture in a
form reasonably satisfactory to the Trustee, (c) immediately after such
transaction no Default or Event of Default exists and (d) except in the case of
a merger of the Company with or into a Wholly Owned Restricted Subsidiary of the
Company, the Company or the Person formed by or surviving any such consolidation
or merger (if other than the Company), or to which such sale, assignment,
transfer, lease, conveyance or other disposition shall have been made (A) will
have Consolidated Net Worth immediately after the transaction equal to or
greater than the Consolidated Net Worth of the Company immediately preceding the
transaction and (B) will, at the time of such transaction and after giving pro
forma effect thereto as if such transaction had occurred at the beginning of the
applicable four-quarter period, be permitted to incur at least $1.00 of
additional Indebtedness pursuant to the Consolidated Interest Coverage Ratio
test set forth in Section 4.09 hereof.

     In connection with any consolidation, merger or disposition contemplated by
this provision, the Company shall deliver, or cause to be delivered, to the
Trustee, in form and substance reasonably satisfactory to the Trustee, (i) an
Officers' Certificate stating that such consolidation, merger or disposition and
any supplemental indenture in respect thereto comply with this provision and
that all conditions precedent in the Indenture provided for relating to such
transaction or transactions have been complied with and (ii) an Opinion of
Counsel stating that the requirements of Section 5.01(a) and (b) have been
satisfied.

                                    - 48 -
<PAGE>
 
Section 5.02.  Successor Corporation Substituted.

     Upon any consolidation or merger, or any sale, assignment, transfer, lease,
conveyance or other disposition of all or substantially all of the properties or
assets of the Company in accordance with Section 5.01 hereof, the successor
corporation formed by such consolidation or into or with which the Company is
merged or to which such sale, assignment, transfer, lease, conveyance or other
disposition is made shall succeed to, and be substituted for (so that from and
after the date of such consolidation, merger, sale, assignment, transfer, lease,
conveyance or other disposition, the provisions of this Indenture referring to
the "Company" shall refer instead to the successor corporation and not to the
Company), and may exercise every right and power of the Company under this
Indenture with the same effect as if such successor corporation had been named
as the Company herein; provided, however, that the predecessor Company shall not
be relieved from its obligations under this Indenture or the Notes in the case
of any such lease.

                                  ARTICLE 6 
                             DEFAULTS AND REMEDIES

Section 6.01.  Events of Default.

     An "Event of Default" occurs if: 

          (a)  the Company defaults in the payment when due of interest on, or
     Liquidated Damages, if any, with respect to, the Notes, and such default
     continues for a period of 30 days;

          (b)  the Company defaults in the payment when due of principal of or
     premium, if any, on the Notes;

          (c)  the Company fails to comply with any of the provisions of Section
     4.10, 4.15 or 5.01 hereof;

          (d)  the Company fails to observe or perform any other covenant or
     other agreement in this Indenture or the Notes for 60 days after notice to
     the Company by the Trustee or the Holders of at least 25% in principal
     amount of the Notes then outstanding of such failure;

          (e)  a default occurs under any mortgage, indenture or instrument
     under which there may be issued or by which there may be secured or
     evidenced any Indebtedness for money borrowed by the Company or any of its
     Restricted Subsidiaries (or the payment of which is guaranteed by the
     Company or any of its Restricted Subsidiaries), whether such Indebtedness
     or guarantee now exists, or is created after the Issue Date, which default
     (i) is caused by a failure to pay principal of or premium or interest on
     such Indebtedness prior to the expiration of any grace period provided in
     such Indebtedness (a "Payment Default") or (ii) results in the acceleration
     of such Indebtedness prior to its express maturity and, in each case, the
     principal amount of any such Indebtedness, together with the principal
     amount of any other such Indebtedness under which there has been a Payment
     Default or the maturity

                                    - 49 -
<PAGE>
 
     of which has been so accelerated, aggregates $5.0 million or more; and
     provided, further, that if such default is cured or waived or any such
     acceleration rescinded, or such Indebtedness is repaid, within a period of
     10 days from the continuation of such default beyond the applicable grace
     period or the occurrence of such acceleration, as the case may be, an Event
     of Default and any consequential acceleration of the Notes shall be
     automatically rescinded, so long as such rescission does not conflict with
     any judgment or decree;

          (f)  a final judgment or final judgments for the payment of money are
     entered by a court or courts of competent jurisdiction against the Company
     or any of its Restricted Subsidiaries  and such judgment or judgments are
     not paid or discharged for a period (during which execution shall not be
     effectively stayed) of 60 days, provided that the aggregate of all such
     undischarged judgments exceeds $5.0 million;

          (g)  the failure of any Guarantor to perform any covenant set forth in
     its Subsidiary Guarantee or the repudiation by any Guarantor of its
     obligations under its Subsidiary Guarantee or the unenforceability of any
     Subsidiary Guarantee for any reason;

          (h)  the Company or any Guarantor pursuant to or within the meaning of
     Bankruptcy Law:

               (i)  commences a voluntary case,

               (ii) consents to the entry of an order for relief against it in
          an involuntary case,

               (iii)     consents to the appointment of a Custodian of it or for
          all or substantially all of its property,

               (iv) makes a general assignment for the benefit of its creditors,
     or

               (v)  generally is not paying its debts as they become due; or

          (i)  a court of competent jurisdiction enters an order or decree under
     any Bankruptcy Law that:

               (i)  is for relief against the Company or any Guarantor in an
          involuntary case,

               (ii) appoints a Custodian of the Company or any Guarantor or for
          all or substantially all of the property of the Company or any
          Guarantor, or

               (iii)     orders the liquidation of the Company or any Guarantor,

     and the order or decree remains unstayed and in effect for 60 consecutive
     days.

                                    - 50 -
<PAGE>
 
Section 6.02.  Acceleration.

     If any Event of Default occurs and is continuing, the Trustee or the
Holders of at least 25% in principal amount of the then outstanding Notes may
declare all the Notes to be due and payable immediately.  Upon any such
declaration, the Notes shall become due and payable immediately. Notwithstanding
the foregoing, if an Event of Default specified in clause (h) or (i) of Section
6.01 hereof occurs with respect to the Company or any Guarantor, all outstanding
Notes shall be due and payable immediately without further action or notice.
The Holders of a majority in principal amount of the then outstanding Notes by
written notice to the Trustee may on behalf of all of the Holders rescind an
acceleration and its consequences if the rescission would not conflict with any
judgment or decree and if all existing Events of Default (except nonpayment of
principal, interest, premium or Liquidated Damages, if any, that have become due
solely because of the acceleration) have been cured or waived.

     If an Event of Default occurs by reason of any willful action (or inaction)
taken (or not taken) by or on behalf of the Company with the intention of
avoiding payment of the premium that the Company would have had to pay if the
Company then had elected to redeem the Notes pursuant to Section 3.07 hereof,
then, upon acceleration of the Notes, an equivalent premium shall also become
and be immediately due and payable, to the extent permitted by law, anything in
this Indenture or in the Notes to the contrary notwithstanding.

Section 6.03.  Other Remedies.

     If an Event of Default occurs and is continuing, the Trustee may pursue any
available remedy to collect the payment of principal of and premium, interest
and Liquidated Damages, if any, on the Notes or to enforce the performance of
any provision of the Notes or this Indenture.

     The Trustee may maintain a proceeding even if it does not possess any of
the Notes or does not produce any of them in the proceeding.  A delay or
omission by the Trustee or any Holder of a Note in exercising any right or
remedy accruing upon an Event of Default shall not impair the right or remedy or
constitute a waiver of or acquiescence in the Event of Default.  All remedies
are cumulative to the extent permitted by law.

Section 6.04.  Waiver of Past Defaults.

     Holders of a majority in principal amount of the then outstanding Notes by
notice to the Trustee may on behalf of the Holders of all of the Notes waive any
existing Default or Event of Default and its consequences hereunder, except a
continuing Default or Event of Default in the payment of the principal of or
premium, interest or Liquidated Damages, if any, on the Notes (including in
connection with an offer to purchase).  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.

                                    - 51 -
<PAGE>
 
Section 6.05.  Control by Majority.

     Holders of a majority in principal amount of the then outstanding Notes may
direct the time, method and place of conducting any proceeding for exercising
any remedy available to the Trustee or exercising any trust or power conferred
on it.  However, the Trustee may refuse to follow any direction that conflicts
with law or this Indenture or that the Trustee determines may be unduly
prejudicial to the rights of other Holders of Notes or that may involve the
Trustee in personal liability.

Section 6.06.  Limitation on Suits.

     A Holder of a Note may pursue a remedy with respect to this Indenture or
     the Notes only if:

          (a)  the Holder of a Note gives to the Trustee written notice of a
     continuing Event of Default;

          (b)  the Holders of at least 25% in principal amount of the then
     outstanding Notes make a written request to the Trustee to pursue the
     remedy;

          (c)  such Holder of a Note or Holders of Notes offer and, if
     requested, provide to the Trustee indemnity satisfactory to the Trustee
     against any loss, liability or expense;

          (d)  the Trustee does not comply with the request within 60 days after
     receipt of the request and the offer and, if requested, the provision of
     indemnity; and

          (e)  during such 60-day period the Holders of a majority in principal
     amount of the then outstanding Notes do not give the Trustee a direction
     inconsistent with the request.

A Holder of a Note may not use this Indenture to prejudice the rights of another
Holder of a Note or to obtain a preference or priority over another Holder of a
Note.

Section 6.07.  Rights of Holders of Notes to Receive Payment.

     Notwithstanding any other provision of this Indenture, the right of any
Holder of a Note to receive payment of principal of and premium, interest and
Liquidated Damages, if any, on the Note, on or after the respective due dates
expressed in the Note (including in connection with an offer to purchase), or to
bring suit for the enforcement of any such payment on or after such respective
dates, shall not be impaired or affected without the consent of such Holder.

Section 6.08.  Collection Suit by Trustee.

     If an Event of Default specified in Section 6.01(a) or (b) occurs and is
continuing, the Trustee is authorized to recover judgment in its own name and as
trustee of an express trust against the Company for the whole amount of
principal of, premium, interest and Liquidated Damages, if any, remaining unpaid
on the Notes and interest on overdue principal and, to the extent lawful,
interest and Liquidated Damages, if any, and such further amount as shall be
sufficient to cover the costs and

                                    - 52 -
<PAGE>
 
expenses of collection, including the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel.

Section 6.09.  Trustee May File Proofs of Claim.

     The Trustee is authorized to file such proofs of claim and other papers or
documents as may be necessary or advisable in order to have the claims of the
Trustee (including any claim for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel) and the
Holders of the Notes allowed in any judicial proceedings relative to the Company
(or any other obligor upon the Notes), its creditors or its property and shall
be entitled and empowered to collect, receive and distribute any money or other
property payable or deliverable on any such claims and any custodian in any such
judicial proceeding is hereby authorized by each Holder to make such payments to
the Trustee, and in the event that the Trustee shall consent to the making of
such payments directly to the Holders, to pay to the Trustee any amount due to
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 7.07 hereof.  To the extent that the payment of any such compensation,
expenses, disbursements and advances of the Trustee, its agents and counsel, and
any other amounts due the Trustee under Section 7.07 hereof out of the estate in
any such proceeding, shall be denied for any reason, payment of the same shall
be secured by a Lien on, and shall be paid out of, any and all distributions,
dividends, money, securities and other properties that the Holders may be
entitled to receive in such proceeding whether in liquidation or under any plan
of reorganization or arrangement or otherwise.  Nothing herein contained shall
be deemed to authorize the Trustee to authorize or consent to or accept or adopt
on behalf of any Holder any plan of reorganization, arrangement, adjustment or
composition affecting the Notes or the rights of any Holder, or to authorize the
Trustee to vote in respect of the claim of any Holder in any such proceeding.

Section 6.10.  Priorities.

     If the Trustee collects any money pursuant to this Article, it shall pay
out the money in the following order:

          First:  to the Trustee, its agents and attorneys for amounts due under
     Section 7.07 hereof, including payment of all compensation, expense and
     liabilities incurred, and all advances made, by the Trustee and the
     Trustee's costs and expenses of collection;

          Second:  to Holders of Notes for amounts due and unpaid on the Notes
     for principal, premium, interest and Liquidated Damages, if any, ratably,
     without preference or priority of any kind, according to the amounts due
     and payable on the Notes for principal, premium, interest and Liquidated
     Damages, if any, respectively; and

          Third:  to the Company or to such party as a court of competent
     jurisdiction shall direct.

     The Trustee may fix a record date and payment date for any payment to
Holders of Notes pursuant to this Section 6.10.

                                    - 53 -
<PAGE>
 
Section 6.11.  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 a
Trustee, a court in its discretion may require the filing by any party litigant
in the suit of an undertaking to pay the costs of the suit, and the court in its
discretion may assess reasonable costs, including reasonable attorneys' fees,
against any party litigant in the suit, having due regard to the merits and good
faith of the claims or defenses made by the party litigant.  This Section does
not apply to a suit by the Trustee, a suit by a Holder of a Note pursuant to
Section 6.07 hereof, or a suit by Holders of more than 10% in principal amount
of the then outstanding Notes.

                                   ARTICLE 7
                                    TRUSTEE

Section 7.01.  Duties of Trustee.

     (a)  If an Event of Default has occurred and is continuing, the Trustee
shall exercise such of the rights and powers vested in it by this Indenture, and
use the same degree of care and skill in its exercise, as a prudent man would
exercise or use under the circumstances in the conduct of his own affairs.

     (b)  Except during the continuance of an Event of Default: 

          (i)  the duties of the Trustee shall be determined solely by the
     express provisions of this Indenture and the Trustee need perform only
     those duties that are specifically set forth in this Indenture and no
     others, and no implied covenants or obligations shall be read into this
     Indenture against the Trustee; and

          (ii) in the absence of bad faith on its part, the Trustee may
     conclusively rely, as to the truth of the statements and the correctness of
     the opinions expressed therein, upon certificates or opinions furnished to
     the Trustee and conforming to the requirements of this Indenture.  However,
     the Trustee shall examine the certificates and opinions to determine
     whether or not they conform to the requirements of this Indenture.

     (c)  The Trustee may not be relieved from liabilities for its own negligent
action, its own negligent failure to act, or its own willful misconduct, except
that:

          (i)  this paragraph does not limit the effect of paragraph (b) of this
          Section 7.01;

          (ii) the Trustee shall not be liable for any error of judgment made in
     good faith by a Responsible Officer, unless it is proved that the Trustee
     was negligent in ascertaining the pertinent facts; and

          (iii)     the Trustee shall not be liable with respect to any action
     it takes or omits to take in good faith in accordance with a direction
     received by it pursuant to Section 6.05 hereof.

                                    - 54 -
<PAGE>
 
     (d)  Whether or not therein expressly so provided, every provision of this
Indenture that in any way relates to the Trustee is subject to paragraphs (a),
(b) and (c) of this Section 7.01.

     (e)  No provision of this Indenture shall require the Trustee to expend or
risk its own funds or incur any liability.  The Trustee shall be under no
obligation to exercise any of its rights and powers under this Indenture at the
request of any Holders, unless such Holder shall have offered to the Trustee
security and indemnity satisfactory to it against any loss, liability or
expense.

     (f)  The Trustee shall not be liable for interest on any money received by
it except as the Trustee may agree in writing with the Company.  Money held in
trust by the Trustee need not be segregated from other funds except to the
extent required by law.

Section 7.02.  Rights of Trustee.

     (a)  The Trustee may conclusively rely upon any document believed by it to
be genuine and to have been signed or presented by the proper Person.  The
Trustee need not investigate any fact or matter stated in the document.

     (b)  Before the Trustee acts or refrains from acting, it may require an
Officers' Certificate or an Opinion of Counsel or both.  The Trustee shall not
be liable for any action it takes or omits to take in good faith in reliance on
such Officers' Certificate or Opinion of Counsel.  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 from liability in respect of
any action taken, suffered or omitted by it hereunder in good faith and in
reliance thereon.

     (c)  The Trustee may act through its attorneys and agents and shall not be
responsible for the misconduct or negligence of any agent appointed with due
care.

     (d)  The Trustee shall not be liable for any action it takes or omits to
take in good faith that it believes to be authorized or within the rights or
powers conferred upon it by this Indenture.

     (e)  Unless otherwise specifically provided in this Indenture, any demand,
request, direction or notice from the Company shall be sufficient if signed by
an Officer of the Company.

     (f)  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 unless such Holders shall have offered to the Trustee reasonable
security or indemnity against the costs, expenses and liabilities that might be
incurred by it in compliance with such request or direction.

     (g)  The Trustee shall have no duty to inquire as to the performance of the
Company's covenants in Article 4 hereof.  In addition, the Trustee shall not be
deemed to have knowledge of any Default or Event of Default except: (1) any
Event of Default occurring pursuant to Section 6.01(a) or 6.01(b) hereof; or (2)
any Default or Event of Default of which is Responsible Officer shall have
received written notification or obtained actual knowledge.

                                    - 55 -
<PAGE>
 
Section 7.03.  Individual Rights of Trustee.

     The Trustee in its individual or any other capacity may become the owner or
pledgee of Notes and may otherwise deal with the Company, any Guarantor or any
Affiliate of the Company with the same rights it would have if it were not
Trustee.  However, in the event that the Trustee acquires any conflicting
interest it must eliminate such conflict within 90 days, apply to the SEC for
permission to continue as trustee or resign.  Any Agent may do the same with
like rights and duties. The Trustee is also subject to Sections 7.10 and 7.11
hereof.

Section 7.04.  Trustee's Disclaimer.

     The Trustee shall not be responsible for and makes no representation as to
the validity or adequacy of this Indenture or the Notes, it shall not be
accountable for the Company's use of the proceeds from the Notes or any money
paid to the Company or upon the Company's direction under any provision of this
Indenture, it shall not be responsible for the use or application of any money
received by any Paying Agent other than the Trustee, and it shall not be
responsible for any statement or recital herein or any statement in the Notes or
any other document in connection with the sale of the Notes or pursuant to this
Indenture other than its certificate of authentication.

Section 7.05.  Notice of Defaults.

     If a Default or Event of Default occurs and is continuing and if it is
known to the Trustee, the Trustee shall mail to Holders of Notes a notice of the
Default or Event of Default within 90 days after it occurs.  Except in the case
of a Default or Event of Default in payment of principal of, premium, if any, or
interest on any Note, the Trustee may withhold the notice if and so long as a
committee of its Responsible Officers in good faith determines that withholding
the notice is in the interests of the Holders of the Notes.

Section 7.06.  Reports by Trustee to Holders of the Notes.

     Within 60 days after each May 15 beginning with the May 15 following the
Issue Date, and for so long as Notes remain outstanding, the Trustee shall mail
to the Holders of the Notes a brief report dated as of such reporting date that
complies with TIA (S)313(a) (but if no event described in TIA (S) 313(a) has
occurred within the twelve months preceding the reporting date, no report need
be transmitted). The Trustee also shall comply with TIA (S) 313(b)(2) and (S)
313(b)(1).  The Trustee shall also transmit by mail all reports as required by
TIA (S) 313(c).

     A copy of each report at the time of its mailing to the Holders of Notes
shall be mailed to the Company and filed with the SEC and each stock exchange on
which the Notes are listed in accordance with TIA(S) 313(d).  The Company shall
promptly notify the Trustee when the Notes are listed on any stock exchange.

                                    - 56 -
<PAGE>
 
Section 7.07.  Compensation and Indemnity.

     The Company shall pay to the Trustee from time to time reasonable
compensation for its acceptance of this Indenture and services hereunder.  The
Trustee's compensation shall not be limited by any law on compensation of a
trustee of an express trust.  The Company shall reimburse the Trustee promptly
upon request for all reasonable disbursements, advances and expenses incurred or
made by it in addition to the compensation for its services.  Such expenses
shall include the reasonable compensation, disbursements and expenses of the
Trustee's agents and counsel.

     The Company and the Guarantors shall indemnify the Trustee against any and
all losses, liabilities or expenses incurred by it arising out of or in
connection with the acceptance or administration of its duties under this
Indenture, including the costs and expenses of enforcing this Indenture against
the Company (including this Section 7.07) and defending itself against any claim
(whether asserted by the Company, any Guarantor or any Holder or any other
person) or liability in connection with the exercise or performance of any of
its powers or duties hereunder, except to the extent any such loss, liability or
expense may be attributable to its negligence, bad faith or willful misconduct.
The Trustee shall notify the Company promptly of any claim for which it may seek
indemnity.  Failure by the Trustee to so notify the Company shall not relieve
the Company or the Guarantors of their obligations hereunder.  The Company shall
defend the claim and the Trustee shall cooperate in the defense.  The Trustee
may have separate counsel and the Company shall pay the reasonable fees and
expenses of such counsel.  The Company need not pay for any settlement made
without its consent, which consent shall not be unreasonably withheld.

     The obligations of the Company and the Guarantors under this Section 7.07
shall survive the satisfaction and discharge of this Indenture.

     To secure the Company's payment obligations in this Section 7.07, the
Trustee shall have a Lien prior to the Notes on all money or property held or
collected by the Trustee, except that held in trust to pay principal and
interest on particular Notes.  Such Lien shall survive the satisfaction and
discharge of this Indenture.

     When the Trustee incurs expenses or renders services after an Event of
Default specified in Section 6.01(h) or (i) hereof occurs, the expenses and the
compensation for the services (including the fees and expenses of its agents and
counsel) are intended to constitute expenses of administration under any
Bankruptcy Law.

     The Trustee shall comply with the provisions of TIA (S) 313(b)(2) to the
     extent applicable.

Section 7.08.  Replacement of Trustee.

     A resignation or removal of the Trustee and appointment of a successor
Trustee shall become effective only upon the successor Trustee's acceptance of
appointment as provided in this Section.

     The Trustee may resign in writing at any time and be discharged from the
trust hereby created by so notifying the Company.  The Holders of Notes of a
majority in principal amount of the then

                                    - 57 -
<PAGE>
 
outstanding Notes may remove the Trustee by so notifying the Trustee and the
Company in writing.  The Company may remove the Trustee if:

          (a)  the Trustee fails to comply with Section 7.10 hereof; 

          (b)  the Trustee is adjudged a bankrupt or an insolvent or an order
     for relief is entered with respect to the Trustee under any Bankruptcy Law;

          (c)  a Custodian or public officer takes charge of the Trustee or its
     property; or

          (d)  the Trustee becomes incapable of acting.

     If the Trustee resigns or is removed or if a vacancy exists in the office
of Trustee for any reason, the Company shall promptly appoint a successor
Trustee.  Within one year after the successor Trustee takes office, the Holders
of a majority in principal amount of the then outstanding Notes may appoint a
successor Trustee to replace the successor Trustee appointed by the Company.

     If a successor Trustee does not take office within 60 days after the
retiring Trustee resigns or is removed, the retiring Trustee, the Company, or
the Holders of Notes of at least 10% in principal amount of the then outstanding
Notes may petition any court of competent jurisdiction for the appointment of a
successor Trustee.

     If the Trustee, after written request by any Holder of a Note who has been
a Holder of a Note for at least six months, fails to comply with Section 7.10
hereof, such Holder of a Note may petition any court of competent jurisdiction
for the removal of the Trustee and the appointment of a successor Trustee.

     A successor Trustee shall deliver a written acceptance of its appointment
to the retiring Trustee and to the Company.  Thereupon, the resignation or
removal of the retiring Trustee shall become effective, and the successor
Trustee shall have all the rights, powers and duties of the Trustee under this
Indenture.  The successor Trustee shall mail a notice of its succession to
Holders of the Notes.  The retiring Trustee shall promptly transfer all property
held by it as Trustee to the successor Trustee, provided all sums owing to the
Trustee hereunder have been paid and subject to the Lien provided for in Section
7.07 hereof.  Notwithstanding replacement of the Trustee pursuant to this
Section 7.08, the Company's obligations under Section 7.07 hereof shall continue
for the benefit of the retiring Trustee.

Section 7.09.  Successor Trustee by Merger, etc.

     If the Trustee consolidates, merges or converts into, or transfers all or
substantially all of its corporate trust business to, another corporation, the
successor corporation without any further act shall be the successor Trustee.
As soon as practicable, the successor Trustee shall mail a notice of its
succession to the Company and the Holders of the Notes.

                                    - 58 -
<PAGE>
 
Section 7.10.  Eligibility; Disqualification.

     There shall at all times be a Trustee hereunder that is a corporation
organized and doing business under the laws of the United States of America or
of any state thereof that is authorized under such laws to exercise corporate
trustee power, that is subject to supervision or examination by federal or state
authorities and that has a combined capital and surplus of at least $100 million
as set forth in its most recent published annual report of condition.

     This Indenture shall always have a Trustee who satisfies the requirements
of TIA (S) 310(a)(1), (2) and (5).  The Trustee is subject to TIA (S) 310(b).

Section 7.11.  Preferential Collection of Claims Against Company.

     The Trustee is subject to TIA (S) 311(a), excluding any creditor
relationship listed in TIA (S) 311(b). A Trustee who has resigned or been
removed shall be subject to TIA (S) 311(a) to the extent indicated therein.

                                   ARTICLE 8
                   LEGAL DEFEASANCE AND COVENANT DEFEASANCE

Section 8.01.  Option to Effect Legal Defeasance or Covenant Defeasance.

     The Company may, at the option of its Board of Directors evidenced by a
resolution set forth in an Officers' Certificate, at any time, exercise its
rights under either Section 8.02 or 8.03 hereof with respect to all outstanding
Notes upon compliance with the conditions set forth below in this Article 8.

Section 8.02.  Legal Defeasance and Discharge.

     Upon the Company's exercise under Section 8.01 hereof of the option
applicable to this Section 8.02, the Company shall, subject to the satisfaction
of the conditions set forth in Section 8.04 hereof, be deemed to have discharged
its obligations with respect to all outstanding Notes, and each Guarantor shall
be deemed to have discharged its obligations with respect to its Subsidiary
Guarantee, on the date the conditions set forth in Section 8.04 below are
satisfied (hereinafter, "Legal Defeasance").  For this purpose, Legal Defeasance
means that the Company shall be deemed to have paid and discharged the entire
Indebtedness represented by the outstanding Notes, and each Guarantor shall be
deemed to have paid and discharged its Subsidiary Guarantee (which in each case
shall thereafter be deemed to be "outstanding" only for the purposes of Section
8.05 hereof and the other Sections of this Indenture referred to in (a) and (b)
below) and to have satisfied all its other obligations under such Notes or
Subsidiary Guarantee and this Indenture (and the Trustee, on demand of and at
the expense of the Company, shall execute proper instruments acknowledging the
same), except for the following provisions which shall survive until otherwise
terminated or discharged hereunder:  (a) the rights of Holders of outstanding
Notes to receive solely from the trust fund described in Section 8.04 hereof,
and as more fully set forth in such Section, payments in respect of the
principal of and premium, if any, interest and Liquidated Damages, if any, on
such Notes when such payments are due, (b) the Company's obligations with
respect to such Notes under

                                    - 59 -
<PAGE>
 
Sections 2.03, 2.04, 2.07, 2.10 and 4.02 hereof, (c) the rights, powers, trusts,
duties and immunities of the Trustee hereunder and the Company's obligations in
connection therewith and (d) this Article 8. Subject to compliance with this
Article 8, the Company may exercise its option under this Section 8.02
notwithstanding the prior exercise of its option under Section 8.03 hereof.

Section 8.03.  Covenant Defeasance.

     Upon the Company's exercise under Section 8.01 hereof of the option
applicable to this Section 8.03, the Company and each Guarantor shall, subject
to the satisfaction of the conditions set forth in Section 8.04 hereof, be
released from its obligations under the covenants contained in Article 4 (other
than those in Sections 4.01, 4.02, 4.06 and 4.14) and in clauses (c) and (d) of
Section 5.01 hereof on and after the date the conditions set forth below are
satisfied (hereinafter, "Covenant Defeasance"), and the Notes shall thereafter
be deemed not "outstanding" for the purposes of any direction, waiver, consent
or declaration or act of Holders (and the consequences of any thereof) in
connection with such covenants, but shall continue to be deemed "outstanding"
for all other purposes hereunder (it being understood that such Notes shall not
be deemed outstanding for accounting purposes).  For this purpose, Covenant
Defeasance means that, with respect to the outstanding Notes, the Company and
any Guarantor may omit to comply with and shall have no liability in respect of
any term, condition or limitation set forth in any such covenant, whether
directly or indirectly, by reason of any reference elsewhere herein to any such
covenant or by reason of any reference in any such covenant to any other
provision herein or in any other document and such omission to comply shall not
constitute a Default or an Event of Default under Section 6.01 hereof, but,
except as specified above, the remainder of this Indenture and such Notes shall
be unaffected thereby.  In addition, upon the Company's exercise under Section
8.01 hereof of the option applicable to this Section 8.03 hereof, subject to the
satisfaction of the conditions set forth in Section 8.04 hereof, Sections
6.01(e) through 6.01(g) hereof shall not constitute Events of Default.

Section 8.04.  Conditions to Legal or Covenant Defeasance.

     In order to exercise either Legal Defeasance or Covenant Defeasance:

          (a)  the Company must irrevocably deposit with the Trustee, in trust,
     for the benefit of the Holders, cash in United States dollars, non-callable
     Government Securities, or a combination thereof, in such amounts as will be
     sufficient, in the opinion of a nationally recognized firm of independent
     public accountants, to pay the principal of and premium, interest and
     Liquidated Damages, if any, on the outstanding Notes on the stated maturity
     thereof or on the applicable redemption date, as the case may be, and the
     Company must specify whether the Notes are being defeased to maturity or to
     a particular redemption date;

          (b)  in the case of an election under Section 8.02 hereof, the Company
     shall have delivered to the Trustee an Opinion of Counsel in the United
     States reasonably acceptable to the Trustee confirming that (A) the Company
     has received from, or there has been published by, the Internal Revenue
     Service a ruling or (B) since the Issue Date, there has been a change in
     the applicable federal income tax law, in either case to the effect that,
     and based thereon such Opinion of Counsel shall confirm that, the Holders
     of the outstanding Notes will not recognize income, gain or loss for
     federal income tax purposes as a result of

                                    - 60 -
<PAGE>
 
     such Legal 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 Legal Defeasance had not occurred;

          (c)  in the case of an election under Section 8.03 hereof, the Company
     shall have delivered to the Trustee an Opinion of Counsel in the United
     States reasonably acceptable to the Trustee confirming that the Holders of
     the outstanding Notes will not recognize income, gain or loss for federal
     income tax purposes as a result of such Covenant Defeasance and will be
     subject to federal income tax 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;

          (d)  no Default or Event of Default shall have occurred and be
     continuing on the date of such deposit (other than a Default or Event of
     Default resulting from the incurrence of Indebtedness, all or a portion of
     the proceeds of which will be used to defease the Notes pursuant to this
     Article 8 concurrently with such incurrence or within 30 days thereof);

          (e)  such Legal Defeasance or Covenant Defeasance shall not result in
     a breach or violation of, or constitute a default under, any material
     agreement or instrument (other than this Indenture) to which the Company or
     any of its Restricted Subsidiaries is a party or by which the Company or
     any of its Restricted Subsidiaries is bound;

          (f)  the Company shall have delivered to the Trustee an Opinion of
     Counsel (which may be based on such solvency certificates or solvency
     opinions as counsel deems necessary or appropriate) to the effect that the
     trust funds will not be subject to the effect of any applicable bankruptcy,
     insolvency, reorganization or similar laws affecting creditors' rights
     generally;

          (g)  the Company shall have delivered to the Trustee an Officers'
     Certificate stating that the deposit was not made by the Company with the
     intent of preferring the Holders over any other creditors of the Company or
     with the intent of defeating, hindering, delaying or defrauding creditors
     of the Company or others; and

          (h)  the Company shall have delivered to the Trustee an Officers'
     Certificate and an Opinion of Counsel, each stating that all conditions
     precedent provided for or relating to the Legal Defeasance or the Covenant
     Defeasance have been complied with.

Section 8.05.  Deposited Money and Government Securities to be Held in Trust;
               Other Miscellaneous Provisions.

     Subject to Section 8.06 hereof, all money and non-callable Government
Securities (including the proceeds thereof) deposited with the Trustee pursuant
to Section 8.04 hereof in respect of the outstanding Notes shall be held in
trust and applied by the Trustee, in accordance with the provisions of such
Notes and this Indenture, to the payment, either directly or through any Paying
Agent (including the Company acting as Paying Agent) as the Trustee may
determine, to the Holders of such Notes of all sums due and to become due
thereon in respect of principal, premium, if any, and

                                    - 61 -
<PAGE>
 
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 cash or non-callable Government
Securities deposited pursuant to Section 8.04 hereof 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 Notes.

     Anything in this Article 8 to the contrary notwithstanding, the Trustee
shall deliver or pay to the Company from time to time upon the request of the
Company any money or non-callable Government Securities held by it as provided
in Section 8.04 hereof which, in the opinion of a nationally recognized firm of
independent public accountants expressed in a written certification thereof
delivered to the Trustee (which may be the opinion delivered under Section
8.04(a) hereof), are in excess of the amount thereof that would then be required
to be deposited to effect an equivalent Legal Defeasance or Covenant Defeasance.

Section 8.06.  Repayment to Company.

     Subject to applicable escheat and abandoned property laws, 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 or Liquidated Damages, if
any, or interest on any Note and remaining unclaimed for two years after such
principal, and premium or Liquidated Damages, if any, or interest has become due
and payable shall be paid to the Company on its request or (if then held by the
Company) shall be discharged from such trust; and the Holder of such Note shall
thereafter, as a secured 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 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.

Section 8.07.  Reinstatement.

     If the Trustee or Paying Agent is unable to apply any United States dollars
or non-callable Government Securities in accordance with Section 8.05 hereof, 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 Notes shall be revived and
reinstated as though no deposit had occurred pursuant to Section 8.02 or 8.03
hereof until such time as the Trustee or Paying Agent is permitted to apply all
such money in accordance with Section 8.05 hereof; provided, however, that, if
the Company makes any payment of principal of, premium, if any, or interest on
any Note following the reinstatement of its obligations, the Company shall be
subrogated to the rights of the Holders of such Notes to receive such payment
from the money held by the Trustee or Paying Agent.

                                    - 62 -
<PAGE>
 
                                   ARTICLE 9
                       AMENDMENT, SUPPLEMENT AND WAIVER

Section 9.01.  Without Consent of Holders of Notes.

     Notwithstanding Section 9.02 of this Indenture, the Company, the Guarantors
and the Trustee may amend or supplement this Indenture or the Notes without the
consent of any Holder of a Note:

          (a)  to cure any ambiguity, defect or inconsistency;

          (b)  to provide for uncertificated Notes in addition to or in place of
     certificated Notes;

          (c)  to provide for the assumption of the Company's obligations to the
     Holders of the Notes pursuant to Article 5 hereof;

          (d)  to secure the Notes pursuant to the requirements of Section 4.12
     or otherwise;

          (e)  to make any change that would provide any additional rights or
     benefits to the Holders of the Notes or that does not adversely affect the
     legal rights hereunder of any Holder of the Note;

          (f)  to comply with Article 10 hereof;

          (g)  to add any Guarantor or to release any Guarantor from its
     Subsidiary Guarantee, in each as provided in this Indenture; or

          (h)  to comply with requirements of the SEC in order to effect or
     maintain the qualification of this Indenture under the TIA.

     Upon the request of the Company accompanied by a resolution of its Board of
Directors authorizing the execution of any such amended or supplemental
indenture, and upon receipt by the Trustee of the documents described in Section
7.02 hereof, the Trustee shall join with the Company and the Guarantors in the
execution of any amended or supplemental indenture authorized or permitted by
the terms of this Indenture and to make any further appropriate agreements and
stipulations that may be therein contained, but the Trustee shall not be
obligated to enter into such amended or supplemental Indenture that affects its
own rights, duties or immunities under this Indenture or otherwise.

Section 9.02.  With Consent of Holders of Notes.

     Except as provided below in this Section 9.02, the Company, the Guarantors
and the Trustee may amend or supplement this Indenture and the Notes may be
amended or supplemented with the consent of the Holders of at least a majority
in principal amount of the Notes then outstanding (including, without
limitation, consents obtained in connection with a purchase of, or tender offer
or exchange offer for the Notes), and, subject to Sections 6.04 and 6.07 hereof,
any existing Default

                                    - 63 -
<PAGE>
 
or Event of Default or compliance with any provision of this Indenture or the
Notes may be waived with the consent of the Holders of a majority in principal
amount of the then outstanding Notes (including consents obtained in connection
with a tender offer or exchange offer for the Notes).

     Upon the request of the Company accompanied by a resolution of its Board of
Directors authorizing the execution of any such amended or supplemental
indenture, and upon the filing with the Trustee of evidence satisfactory to the
Trustee of the consent of the Holders of Notes as aforesaid, and upon receipt by
the Trustee of the documents described in Section 9.06 hereof, the Trustee shall
join with the Company and the Guarantors in the execution of such amended or
supplemental indenture unless such amended or supplemental indenture affects the
Trustee's own rights, duties or immunities under this Indenture or otherwise, in
which case the Trustee may in its discretion, but shall not be obligated to,
enter into such amended or supplemental indenture.

     It shall not be necessary for the consent of the Holders of Notes under
this Section 9.02 to approve the particular form of any proposed amendment,
supplement or waiver, but it shall be sufficient if such consent approves the
substance thereof.

     After an amendment, supplement or waiver under this Section becomes
effective, the Company shall mail to the Holders of Notes affected thereby a
notice briefly describing the amendment, supplement or waiver.  Any failure of
the Company to mail such notice, or any defect therein, shall not, however, in
any way impair or affect the validity of any such amended or supplemental
Indenture or waiver.  Subject to Sections 6.04 and 6.07 hereof, the Holders of a
majority in principal amount of the Notes then outstanding may waive compliance
in a particular instance by the Company with any provision of this Indenture or
the Notes.  However, without the consent of each Holder affected, an amendment,
supplement or waiver may not (with respect to any Notes held by a non-consenting
Holder):

          (a)  reduce the principal amount of Notes whose Holders must consent
     to an amendment, supplement or waiver;

          (b)  reduce the principal of or change the fixed maturity of any Note
     or alter any of the provisions with respect to the redemption of the Notes
     (except as provided in Sections 3.09, 4.10 and 4.15 hereof);

          (c)  reduce the rate of or change the time for payment of interest on
     any Note;

          (d)  waive a Default or Event of Default in the payment of principal
     of or premium, interest or Liquidated Damages, if any, on the Notes (except
     a rescission of acceleration of the Notes by the Holders of at least a
     majority in principal amount of the Notes and a waiver of the payment
     default that resulted from such acceleration);

          (e)  make any Note payable in money other than that stated in the
     Notes;

          (f)  make any change in the provisions of this Indenture relating to
     waivers of past Defaults or Events of Default or the rights of Holders of
     Notes to receive payments of

                                    - 64 -
<PAGE>
 
     principal of or premium, interest or Liquidated Damages, if any, on the
     Notes (except as permitted in clause (g) below);

          (g)  waive a redemption payment with respect to any Note (other than a
     payment required by Sections 4.10 and 4.15 hereof);

          (h)  make any change in the ranking of the Notes relative to other
     Indebtedness of the Company or in the Subsidiary Guarantees, in either case
     in a manner adverse to the Holders of Notes; or

          (i)  make any change in the foregoing amendment, supplement and waiver
     provisions.

Section 9.03.  Compliance with Trust Indenture Act.

     Every amendment or supplement to this Indenture or the Notes shall be set
forth in a amended or supplemental Indenture that complies with the TIA as then
in effect.

Section 9.04.  Revocation and Effect of Consents.

     Until an amendment, supplement or waiver becomes effective, a consent to it
by a Holder of a Note is a continuing consent by the Holder of a Note and every
subsequent Holder of a Note or portion of a Note that evidences the same debt as
the consenting Holder's Note, even if notation of the consent is not made on any
Note.  However, any such Holder of a Note or subsequent Holder of a Note may
revoke the consent as to its Note if the Trustee receives written notice of
revocation before the date the waiver, supplement or amendment becomes
effective.  An amendment, supplement or waiver becomes effective in accordance
with its terms and thereafter binds every Holder.

Section 9.05.  Notation on or Exchange of Notes.

     The Trustee may place an appropriate notation about an amendment,
supplement or waiver on any Note thereafter authenticated.  The Company in
exchange for all Notes may issue and the Trustee shall authenticate new Notes
that reflect the amendment, supplement or waiver.

     Failure to make the appropriate notation or issue a new Note shall not
affect the validity and effect of such amendment, supplement or waiver.

Section 9.06.  Trustee to Sign Amendments, etc.

     The Trustee shall sign any amended or supplemental indenture authorized
pursuant to this Article 9 if the amendment or supplement does not adversely
affect the rights, duties, liabilities or immunities of the Trustee.  The
Company may not sign an amendment or supplemental indenture until the Board of
Directors approves it.  In executing any amended or supplemental indenture, the
Trustee shall be entitled to receive and (subject to Section 7.01) shall be
fully protected in relying

                                    - 65 -
<PAGE>
 
upon, an Officers' Certificate and an Opinion of Counsel stating that the
execution of such amended or supplemental indenture is authorized or permitted
by this Indenture.

                                  ARTICLE 10
                              GUARANTEES OF NOTES

Section 10.01. Subsidiary Guarantees.

     Subject to Section 10.06 hereof, the Guarantors hereby, jointly and
severally, unconditionally guarantee to each Holder of a Note authenticated and
delivered by the Trustee and to the Trustee and its successors and assigns,
irrespective of the validity and enforceability of this Indenture, the Notes
held thereby and the Obligations of the Company hereunder and thereunder, that:
(a) the principal of and premium, interest and Liquidated Damages, if any, on
the Notes will be promptly paid in full when due, subject to any applicable
grace period, whether at maturity, by acceleration, redemption or otherwise, and
interest on the overdue principal, premium, (to the extent permitted by law)
interest and Liquidated Damages, if any, on the Notes, and all other payment
Obligations of the Company to the Holders or the Trustee hereunder or thereunder
will be promptly paid in full and performed, all in accordance with the terms
hereof and thereof; and (b) in case of any extension of time of payment or
renewal of any Notes or any of such other Obligations, the same will be promptly
paid in full when due or performed in accordance with the terms of the extension
or renewal, subject to any applicable grace period, whether at stated maturity,
by acceleration, redemption or otherwise.  Failing payment when so due of any
amount so guaranteed or any performance so guaranteed for whatever reason the
Guarantors will be jointly and severally obligated to pay the same immediately.
An Event of Default under this Indenture or the Notes shall constitute an event
of default under the Subsidiary Guarantees, and shall entitle the Holders to
accelerate the obligations of the Guarantors hereunder in the same manner and to
the same extent as the Obligations of the Company.  The Guarantors hereby agree
that their obligations hereunder shall be unconditional, irrespective of the
validity, regularity or enforceability of the Notes or this Indenture, the
absence of any action to enforce the same, any waiver or consent by any Holder
with respect to any provisions hereof or thereof, the recovery of any judgment
against the Company, any action to enforce the same or any other circumstance
(other than complete performance) which might otherwise constitute a legal or
equitable discharge or defense of a Guarantor.  Each Guarantor further, to the
extent permitted by law, hereby waives diligence, presentment, demand of
payment, filing of claims with a court in the event of insolvency or bankruptcy
of the Company, any right to require a proceeding first against the Company,
protest, notice and all demands whatsoever and covenants that this Subsidiary
Guarantee will not be discharged except by complete performance of the
Obligations contained in the Notes and this Indenture.  If any Holder or the
Trustee is required by any court or otherwise to return to the Company, the
Guarantors, or any Custodian, Trustee or other similar official acting in
relation to either the Company or the Guarantors, any amount paid by the Company
or any Guarantor to the Trustee or such Holder, the Subsidiary Guarantees, to
the extent theretofore discharged, shall be reinstated in full force and effect.
Each Guarantor agrees that it shall not be entitled to, and hereby waives, any
right of subrogation in relation to the Holders in respect of any Obligations
guaranteed hereby.  Each Guarantor further agrees that, as between the
Guarantors, on the one hand, and the Holders and the Trustee, on the other hand,
(a) the maturity of the Obligations guaranteed hereby may be accelerated as
provided in Article 6 hereof for the purposes of its Subsidiary Guarantee,
notwithstanding any stay, injunction or other prohibition preventing such
acceleration in respect of

                                    - 66 -
<PAGE>
 
the Obligations guaranteed thereby, and (b) in the event of any declaration of
acceleration of such Obligations as provided in Article 6 hereof, such
Obligations (whether or not due and payable) shall forthwith become due and
payable by the Guarantor for the purpose of its Subsidiary Guarantee.  The
Guarantors shall have the right to seek contribution from any non-paying
Guarantor so long as the exercise of such right does not impair the rights of
the Holders under the Subsidiary Guarantees.

Section 10.02. Execution and Delivery of Subsidiary Guarantee.

     To evidence its Subsidiary Guarantee set forth in Section 10.01 hereof,
each Guarantor hereby agrees that a notation of such Subsidiary Guarantee
substantially in the form of Exhibit D hereto shall be endorsed by manual or
facsimile signature by an Officer of such Guarantor on each Note authenticated
and delivered by the Trustee and that this Indenture shall be executed on behalf
of such Guarantor by an Officer of such Guarantor.

     To the extent required by the provisions of Section 4.13 hereof, the
Company shall cause each of its Restricted Subsidiaries to execute a Subsidiary
Guarantee substantially in the form of Exhibit D.  Such Subsidiary Guarantee
shall be accompanied by a supplemental indenture substantially in the form of
Exhibit E, along with the Opinion of Counsel and Officers' Certificate required
under Section 9.06 of this Indenture; provided, however, that any Subsidiary
that has been properly designated as an Unrestricted Subsidiary in accordance
with this Indenture need not execute a Subsidiary Guarantee for so long as it
continues to constitute an Unrestricted Subsidiary.

     Each Guarantor hereby agrees that its Subsidiary Guarantee shall remain in
full force and effect notwithstanding any failure to endorse on each Note a
notation of such Subsidiary Guarantee.

     If an Officer whose signature is on the Subsidiary Guarantee no longer
holds that office at the time the Trustee authenticates the Note on which a
Subsidiary Guarantee is endorsed, the Subsidiary Guarantee shall be valid
nevertheless.

     The delivery of any Note by the Trustee, after the authentication thereof
hereunder, shall constitute due delivery of the Subsidiary Guarantees on behalf
of the Guarantors.

Section 10.03. Guarantors May Consolidate, etc., on Certain Terms.

     (a)  Except as set forth in Articles 4 and 5 hereof, nothing contained in
this Indenture shall prohibit a merger between a Guarantor and another Guarantor
or a merger between a Guarantor and the Company.

     (b)  No Guarantor shall consolidate with or merge with or into (whether or
not such Guarantor is the surviving Person), another Person (other than the
Company or another Guarantor), whether or not affiliated with such Guarantor,
unless, (i) subject to the provisions of Section 10.04 hereof, the Person formed
by or surviving any such consolidation or merger (if other than such Guarantor)
assumes all the obligations of such Guarantor pursuant to a supplemental
indenture, substantially in the form of Exhibit E hereto, under the Notes and
this Indenture; (ii) immediately after giving effect to such transaction, no
Default or Event of Default exists; (iii) such Guarantor, or any Person formed
by or surviving any such consolidation or merger, would have Consolidated

                                    - 67 -
<PAGE>
 
Net Worth (immediately after giving effect to such transaction), equal to or
greater than the Consolidated Net Worth of such Guarantor immediately preceding
the transaction; and (iv) the Company, at the time of such transaction and after
giving pro forma effect thereto as if such transaction had occurred at the
beginning of the applicable four-quarter period, would be permitted to incur at
least $1.00 of additional Indebtedness pursuant to the Consolidated Interest
Coverage Ratio test set forth in Section 4.09 hereof.

     (c)  In the case of any such consolidation or merger and upon the
assumption by the successor Person, by supplemental indenture, executed and
delivered to the Trustee and substantially in the form of Exhibit E hereto, of
the Subsidiary Guarantee and the due and punctual performance of all of the
covenants of this Indenture to be performed by the Guarantor, such successor
Person shall succeed to and be substituted for the Guarantor with the same
effect as if it had been named herein as a Guarantor; provided, however, that,
solely for purposes of computing Consolidated Net Income for purposes of clause
(c) of the first paragraph of Section 4.07 hereof, the Consolidated Net Income
of any Person other than the Company and its Restricted Subsidiaries shall only
be included for periods subsequent to the effective time of such merger or
consolidation.  Such successor Person thereupon may cause to be signed any or
all of the notations of Subsidiary Guarantees to be endorsed upon all of the
Notes issuable hereunder which theretofore shall not have been signed by the
Company and delivered to the Trustee.  All of the Subsidiary Guarantees so
issued shall in all respects have the same legal rank and benefit under this
Indenture as the Subsidiary Guarantees theretofore and thereafter issued in
accordance with the terms of this Indenture as though all of such Subsidiary
Guarantees had been issued at the Issue Date.

Section 10.04. Releases Following Sale of Assets.

     In the event of a sale or other disposition of all of the assets or Capital
Stock of any Guarantor, by way of merger, consolidation or otherwise, then such
Guarantor (in the event of a sale or other disposition, by way of such a merger,
consolidation or otherwise, of all of the Capital Stock of such Guarantor) or
the Person acquiring the assets (in the event of a sale or other disposition of
all of the assets of such Guarantor) shall be released and relieved of any
obligations under its Subsidiary Guarantee; provided, however, that (i) in the
event such transaction constitutes an Asset Sale, the Net Proceeds from such
sale or other disposition are treated in accordance with the provisions of
Section 4.10 hereof and (ii) the Company is in compliance with all other
provisions of this Indenture applicable to such disposition; provided, further,
that upon such release, the obligations of such Guarantor in respect of any and
all other guarantees of Indebtedness of the Company or a Guarantor are similarly
released.  Upon delivery by the Company to the Trustee of an Officers'
Certificate to the effect of the foregoing, the Trustee shall execute any
documents reasonably required in order to evidence the release of any Guarantor
from its obligations under its Subsidiary Guarantee.  Any Guarantor not released
from its obligations under its Subsidiary Guarantee shall remain liable for the
full amount of principal of and premium, interest and Liquidated Damages, if
any, on the Notes and for the other Obligations of such Guarantor under this
Indenture as provided in this Article 10.

                                    - 68 -
<PAGE>
 
Section 10.05. Releases Following Designation as an Unrestricted Subsidiary.

     In the event that the Company designates a Guarantor to be an Unrestricted
Subsidiary, then such Guarantor shall be released and relieved of any
obligations under its Subsidiary Guarantee; provided that such designation is
conducted in accordance with this Indenture.

Section 10.06. Limitation on Guarantor Liability.

     For purposes hereof, each Guarantor's liability under its Subsidiary
Guarantee shall be limited to the lesser of (a) the aggregate amount of the
Obligations of the Company under the Notes and this Indenture and (b) the
amount, if any, which would not have (i) rendered such Guarantor "insolvent" (as
such term is defined in the Bankruptcy Law and in the Debtor and Creditor Law of
the State of New York) or (ii) left such Guarantor with unreasonably small
capital at the time its Subsidiary Guarantee of the Notes was entered into;
provided, however, that, it will be a presumption in any lawsuit or other
proceeding in which a Guarantor is a party that the amount guaranteed pursuant
to the Subsidiary Guarantee is the amount set forth in clause (a) above unless
any creditor, or representative of creditors of such Guarantor, or debtor in
possession or trustee in bankruptcy of the Guarantor, otherwise proves in such a
lawsuit that the aggregate liability of the Guarantor is the amount set forth in
clause (b) above.  In making any determination as to solvency or sufficiency of
capital of a Guarantor in accordance with the previous sentence, the right of
such Guarantor to contribution from other Guarantors, and any other rights such
Guarantor may have, contractual or otherwise, shall be taken into account.

Section 10.07. "Trustee" to Include Paying Agent.

     In case at any time any Paying Agent other than the Trustee shall have been
appointed by the Company and be then acting hereunder, the term "Trustee" as
used in this Article 10 shall in each case (unless the context shall otherwise
require) be construed as extending to and including such Paying Agent within its
meaning as fully and for all intents and purposes as if such Paying Agent were
named in this Article 10 in place of the Trustee.

                                  ARTICLE 11
                                 MISCELLANEOUS

Section 11.01. Trust Indenture Act Controls.

     If any provision of this Indenture limits, qualifies or conflicts with the
duties imposed by TIA (S) 318(c), the imposed duties shall control.

Section 11.02. Notices.

     Any notice or communication by the Company, any Guarantor or the Trustee to
the others is duly given if in writing (in the English language) and delivered
in person or mailed by first class mail (registered or certified, return receipt
requested), telecopier or overnight air courier guaranteeing next day delivery,
to the others' address:

                                    - 69 -
<PAGE>
 
     If to the Company or the Guarantors:

               Wainoco Oil Corporation
               10000 Memorial Drive, Suite 600
               Houston, Texas   77024-3411
               Attention:  Julie H. Edwards
               Telecopier No.:  (713) 688-0616

     With a copy to:

               Andrews & Kurth L.L.P.
               4200 Chase Tower
               600 Travis Street
               Houston, Texas   77002
               Attention:  Christopher Collins
               Telecopier No.:  (713) 220-4285

     If to the Trustee:

          (1)  For payment, registration, transfer and exchange of the Notes:

               By Hand:
               Chase Bank of Texas, National Association
               One Main Place
               1201 Main Street, 18th Floor
               Dallas, Texas   75202
               Attention:  Registered Bond Events
               Telephone No.:  (214) 672-5125 or (800) 275-2048
               Telecopier No.:  (214) 672-5746

               By Mail:

               Chase Bank of Texas, National Association         
               P. O. Box 2320
               Dallas, Texas   75221-2320
               Attention:  Registered Bond Events
               Telephone No.:  (214) 672-5125 or (800) 275-2048
               Telecopier No.:  (214) 672-5746

                                    - 70 -
<PAGE>
 
          (2)  For all other communications relating to the Notes:

               Chase Bank of Texas, National Association
               Global Trust Services
               600 Travis Street, Suite 1150
               Houston, Texas   77002
               Attention:  Mauri J. Cowen
               Telephone No.:  (713) 216-5811
               Telecopier No.:  (713) 216-5476

     If to the Paying Agent:

               Chase Bank of Texas, National Association
               c/o Texas Commerce Trust Company of New York
               55 Water Street, North Building
               Room 234, Windows 20 and 21
               New York, New York   10041
               Telephone No.:  (212) 638-4020 or (212) 738-4021
               Telecopier No.:  (212) 638-7267

     The Company, any of the Guarantors or the Trustee, by notice to the others
may designate additional or different addresses for subsequent notices or
communications.

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

     Any notice or communication to a Holder shall be mailed by first class
mail, certified or registered, return receipt requested, or by overnight air
courier guaranteeing next day delivery to its address shown on the register kept
by the Registrar. Any notice or communication shall also be so mailed to any
Person described in TIA(S) 313(c), to the extent required by the TIA. Failure to
mail a notice or communication to a Holder or any defect in it shall not affect
its sufficiency with respect to other Holders.

     If a notice or communication is mailed in the manner provided above within
the time prescribed, it is duly given, whether or not the addressee receives it.

     If the Company mails a notice or communication to Holders, it shall mail a
copy to the Trustee and each Agent at the same time.

                                    - 71 -
<PAGE>
 
Section 11.03. Communication by Holders of Notes with Other Holders of Notes.

     Holders may communicate pursuant to TIA (S) 312(b) with other Holders with
respect to their rights under this Indenture or the Notes.  The Company, the
Trustee, the Registrar and anyone else shall have the protection of TIA (S)
312(c).

Section 11.04. Certificate and Opinion as to Conditions Precedent.

     Upon any request or application by the Company to the Trustee to take any
action under this Indenture, the Company shall furnish to the Trustee:

          (a)  an Officers' Certificate in form and substance reasonably
     satisfactory to the Trustee (which shall include the statements set forth
     in Section 11.05 hereof) stating that, in the opinion of the signers, all
     conditions precedent and covenants, if any, provided for in this Indenture
     relating to the proposed action have been satisfied; and

          (b)  an Opinion of Counsel in form and substance reasonably
     satisfactory to the Trustee (which shall include the statements set forth
     in Section 11.05 hereof) stating that, in the opinion of such counsel, all
     such conditions precedent and covenants have been satisfied.

Section 11.05. Statements Required in Certificate or Opinion.

     Each certificate or opinion with respect to compliance with a condition or
covenant provided for in this Indenture (other than a certificate provided
pursuant to TIA (S) 314(a)(4)) shall comply with the provisions of TIA (S)
314(e) and shall include:

          (a)  a statement that the Person making such certificate or opinion
     has read such covenant or condition;

          (b)  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;

          (c)  a statement that, in the opinion of such Person, he or she 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 satisfied; and

          (d)  a statement as to whether or not, in the opinion of such Person,
     such condition or covenant has been satisfied.

Section 11.06. Rules by Trustee and Agents.

     The Trustee may make reasonable rules for action by or at a meeting of
Holders.  The Registrar or Paying Agent may make reasonable rules and set
reasonable requirements for its functions.

                                    - 72 -
<PAGE>
 
Section 11.07. No Personal Liability of Directors, Officers, Employees and
               Stockholders.

     No past, present or future director, officer, employee, incorporator or
stockholder of the Company or any Guarantor, as such, shall have any liability
for any obligations of the Company or any Guarantor under the Notes, the
Subsidiary Guarantees, this Indenture or for any claim based on, in respect of,
or by reason of, such obligations or their creation.  Each Holder by accepting a
Note waives and releases all such liability.  The waiver and release are part of
the consideration for issuance of the Notes.

Section 11.08. Governing Law.

     THE LAW OF THE STATE OF NEW YORK SHALL GOVERN AND BE USED TO CONSTRUE AND
ENFORCE THIS INDENTURE, THE NOTES AND THE SUBSIDIARY GUARANTEES.

Section 11.09. No Adverse Interpretation of Other Agreements.

     This Indenture may not be used to interpret any other indenture, loan or
debt agreement of the Company or its Restricted Subsidiaries or of any other
Person.  Any such indenture, loan or debt agreement may not be used to interpret
this Indenture.

Section 11.10. Successors.

     All agreements of the Company and the Guarantors in this Indenture and the
Notes shall bind their successors.  All agreements of the Trustee in this
Indenture shall bind its successors.

Section 11.11. Severability.

     In case any provision in this Indenture or in the Notes 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 11.12. Counterpart Originals.

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

Section 11.13. Table of Contents, Headings, etc.

     The Table of Contents, Cross-Reference Table and Headings of the Articles
and Sections of this Indenture have been inserted for convenience of reference
only, are not to be considered a part of this Indenture and shall in no way
modify or restrict any of the terms or provisions hereof.

                        [Signatures on following page]

                                    - 73 -
<PAGE>
 
                                  SIGNATURES


                             WAINOCO OIL CORPORATION



                             By: /s/ Julie H. Edwards
                                 -------------------------------------
                                 Name:  Julie H. Edwards
                                 Title:  Senior Vice President Finance
                                          and Chief Financial Officer


                             CHASE BANK OF TEXAS,
                             NATIONAL ASSOCIATION, as Trustee



                             By: /s/ Mauri J. Cowen
                                 -------------------------------------
                                 Mauri J. Cowen
                                 Vice President and Trust Officer