<PAGE>
 
                                                                     EXHIBIT 4.2

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


                             NUEVO ENERGY COMPANY

                                      TO

                       [SUBORDINATED INDENTURE TRUSTEE]
                                    Trustee



                               ________________


                            SUBORDINATED INDENTURE

                               ________________



                          Dated as of [ ]___, 199[ ]

--------------------------------------------------------------------------------
<PAGE>
 
                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                  Page
                                                                                  ----
<S>                                                                                <C>
ARTICLE ONE....................................................................     1
 Section 101.  Definitions.....................................................     1
 Section 102.  Compliance Certificates and Opinions............................     9
 Section 103.  Form of Documents Delivered to Trustee..........................    10
 Section 104.  Acts of Holders; Record Dates...................................    10
 Section 105.  Notices, Etc., to Trustee and Company...........................    12
 Section 106.  Notice to Holders; Waiver.......................................    13
 Section 107.  Conflict with Trust Indenture Act...............................    13
 Section 108.  Effect of Headings and Table of Contents........................    13
 Section 109.  Successors and Assigns..........................................    13
 Section 110.  Separability Clause.............................................    13
 Section 111.  Benefits of Indenture...........................................    13
 Section 112.  Governing Law...................................................    14
 Section 113.  Legal Holidays..................................................    14

ARTICLE TWO....................................................................    14
 Section 201.  Forms Generally.................................................    14
 Section 202.  Form of Trustee's Certificate of Authentication.................    14
 Section 203.  Form of Legend for Global Securities............................    15
 Section 204.  Form of Conversion Notice.......................................    15
 Section 205.  Securities in Global Form.......................................    15

ARTICLE THREE..................................................................    16
 Section 301.  Amount Unlimited; Issuable in Series............................    16
 Section 302.  Denominations...................................................    19
 Section 303.  Execution, Authentication, Delivery and Dating..................    19
 Section 304.  Temporary Securities............................................    20
 Section 305.  Registration, Registration of Transfer and Exchange.............    21
 Section 306.  Mutilated, Destroyed, Lost and Stolen Securities................    22
 Section 307.  Payment of Interest; Interest Rights Preserved..................    23
 Section 308.  Persons Deemed Owners...........................................    24
 Section 309.  Cancellation....................................................    24
 Section 310.  Computation of Interest.........................................    25

ARTICLE FOUR...................................................................    25
 Section 401.  Satisfaction and Discharge of Indenture.........................    25
 Section 402.  Application of Trust Money......................................    26

ARTICLE FIVE...................................................................    26
 Section 501.  Events of Default...............................................    26
 Section 502.  Acceleration of Maturity; Rescission and Annulment..............    28
 Section 503.  Collection of Indebtedness and Suits for Enforcement by Trustee.    29
 Section 504.  Trustee May File Proof of Claim.................................    29
 Section 505.  Trustee May Enforce Claims Without Possession of Securities.....    30
 Section 506.  Application of Money Collected..................................    30
 Section 507.  Limitation on Suits.............................................    30
</TABLE> 

                                      (i)
<PAGE>
 
<TABLE> 
<S>                                                                                <C>
 Section 508.  Unconditional Right of Holders to Receive Principal, Premium and
                    Interest...................................................    31
 Section 509.  Restoration of Rights and Remedies..............................    31
 Section 510.  Rights and Remedies Cumulative..................................    31
 Section 511.  Delay or Omission Not Waiver....................................    32
 Section 512.  Control by Holders..............................................    32
 Section 513.  Waiver of Past Defaults.........................................    32
 Section 514.  Undertaking for Costs...........................................    33
 Section 515.  Waiver of Usury, Stay or Extension Laws.........................    33

ARTICLE SIX....................................................................    33
 Section 601.  Certain Duties and Responsibilities.............................    33
 Section 602.  Notice of Defaults..............................................    33
 Section 603.  Certain Rights of Trustee.......................................    34
 Section 604.  Not Responsible for Recitals or Issuance of Securities..........    34
 Section 605.  May Hold Securities.............................................    35
 Section 606.  Money Held in Trust.............................................    35
 Section 607.  Compensation and Reimbursement..................................    35
 Section 608.  Conflicting Interests...........................................    35
 Section 609.  Corporate Trustee Required; Eligibility.........................    36
 Section 610.  Resignation and Removal, Appointment of Successor...............    36
 Section 611.  Acceptance of Appointment by Successor..........................    37
 Section 612.  Merger, Conversion, Consolidation or Succession to Business.....    38
 Section 613.  Preferential Collection of Claims Against Company...............    38
 Section 614.  Appointment of Authenticating Agent.............................    39

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

ARTICLE EIGHT..................................................................    41
 Section 801.  Company May Consolidate, Etc., Only on Certain Terms............    41
 Section 802.  Successor Substituted...........................................    42

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

ARTICLE TEN....................................................................    45
 Section 1001.  Payment of Principal, Premium and Interest.....................    45
 Section 1002.  Maintenance of Office or Agency................................    46
 Section 1003.  Money for Securities Payments to be Held in Trust..............    46
 Section 1004.  Statement by Officers as to Default............................    47
 Section 1005.  Existence......................................................    47
 Section 1006.  Maintenance of Properties......................................    47
</TABLE> 

                                     (ii)
<PAGE>
 
<TABLE> 
<S>                                                                                <C>
 Section 1007.  Payment of Taxes and Other Claims..............................    48
 Section 1008.  Waiver of Certain Covenants....................................    48
 Section 1009.  Covenants as to Nuevo Trusts...................................    48

ARTICLE ELEVEN.................................................................    49
 Section 1101.  Applicability of Article.......................................    49
 Section 1102.  Election to Redeem; Notice to Trustee..........................    49
 Section 1103.  Selection by Trustee of Securities to be Redeemed..............    49
 Section 1104.  Notice of Redemption...........................................    50
 Section 1105.  Deposit of Redemption Price....................................    51
 Section 1106.  Securities Payable on Redemption Date..........................    51
 Section 1107.  Securities Redeemed in Part....................................    51

ARTICLE TWELVE.................................................................    52
 Section 1201.  Applicability of Article.......................................    52
 Section 1202.  Satisfaction of Sinking Fund Payments with Securities..........    52
 Section 1203.  Redemption of Securities for Sinking Fund......................    52

ARTICLE THIRTEEN...............................................................    53
 Section 1301.  Company's Option to Effect Defeasance or Covenant Defeasance...    53
 Section 1302.  Defeasance and Discharge.......................................    53
 Section 1303.  Covenant Defeasance............................................    53
 Section 1304.  Conditions to Defeasance or Covenant Defeasance................    54
 Section 1305.  Deposited Money and U.S. Government Obligations to be Held in
                     Trust; Miscellaneous Provisions...........................    56
 Section 1306.  Reinstatement..................................................    56

ARTICLE FOURTEEN...............................................................    57
 Section 1401.  Conditions to Defeasance or Covenant Defeasance................    57
 Section 1402.  Exercise of Conversion Privilege...............................    57
 Section 1403.  No Fractional Shares...........................................    58
 Section 1404.  Adjustment of Conversion Price.................................    58
 Section 1405.  Notice of Certain Corporate Actions............................    59
 Section 1406.  Reservation of Shares of Common Stock..........................    60
 Section 1407.  Payment of Certain Taxes upon Conversion.......................    60
 Section 1408.  Nonassessability...............................................    60
 Section 1409.  Effect of Consolidation or Merger on Conversion Privilege......    60
 Section 1410.  Duties of Trustee Regarding Conversion.........................    61
 Section 1411.  Repayment of Certain funds upon Conversion.....................    61

ARTICLE FIFTEEN................................................................    62
 Section 1501.  Securities Subordinate to Senior Indebtedness..................    62
 Section 1502.  Payment Over of Proceeds Upon Dissolution......................    62
 Section 1503.  Prior Payment to Senior Indebtedness Upon Acceleration of
                     Securities................................................    63
 Section 1504.  No Payment When Senior Indebtedness in Default.................    64
 Section 1505.  Payment Permitted in Certain Situations........................    64
 Section 1506.  Subrogation to Rights of Holders of Senior Indebtedness........    64
 Section 1507.  Provisions Solely to Define Relative Rights....................    65
 Section 1508.  Trustee to Effectuate Subordination............................    65
 Section 1509.  No Waiver of Subordination Provisions..........................    65
 Section 1510.  Notice to Trustee..............................................    66
</TABLE> 

                                     (iii)
<PAGE>
 
<TABLE> 
<S>                                                                                <C>
 Section 1511.  Reliance on Judicial Order or Certificate of Liquidating.......    66
 Section 1512.  Trustee Not Fiduciary for Holders of Senior Indebtedness.......    67
 Section 1513.  Rights of Trustee as Holder of Senior Indebtedness.............    67
 Section 1514.  Article Applicable to Paying Agents............................    67
 Section 1515.  Certain Conversions Deemed Payment.............................    67
</TABLE>

                                     (iv)
<PAGE>
 
                             NUEVO ENERGY COMPANY


RECONCILIATION OF CERTAIN SECTIONS OF THIS INDENTURE RELATING TO SECTIONS 310
THROUGH 318, INCLUSIVE, OF THE TRUST INDENTURE ACT OF 1939:

<TABLE>
<CAPTION>
Trust Indenture
Act Section
-----------                                                            ---------
<S>           <C>            <C> 
sec. 310      (a) (1)        ...................................... 
              (a) (2)        ...................................... 
              (2) (3)        ...................................... 
              (a) (4)        ...................................... 
              (b)            ...................................... 
                             ...................................... 
sec. 311      (a)            ...................................... 
              (b)            ...................................... 
sec. 312      (a)            ...................................... 
              (b)            ...................................... 
              (c)            ......................................
sec. 313      (a)            ......................................
              (b)            ......................................
              (c)            ......................................
              (d)            ......................................
sec. 314      (a)            ......................................
              (a) (4)        ......................................
              (b)            ......................................
              (c) (1)        ......................................
              (c) (2)        ...................................... 
              (c) (3)        ......................................
              (d)            ......................................
              (e)            ......................................
sec. 315      (a)            ......................................
              (b)            ......................................
              (c)            ......................................
              (d)            ......................................
              (e)            ...................................... 
sec. 316      (a)            ......................................
              (a) (1) (A)    ......................................  
              (a) (2)        ......................................  
              (b)            ......................................  
</TABLE>
<PAGE>
 
<TABLE>
<S>           <C>            
              (c)            ......................................
sec. 317      (a) (1)        ...................................... 
              (a) (2)        ...................................... 
sec. 317      (a)            ......................................
</TABLE>

NOTE: This reconciliation and tie shall not, for any purpose, be deemed to be a
part of the Indenture.
<PAGE>
 
     INDENTURE, dated as of [               ] ___, 199[ ], between Nuevo Energy
Company, a corporation duly organized and existing under the laws of the State
of Delaware (herein called the "Company"), having its principal office at 1331
Lamar, Suite 1600, Houston, Texas 77010, and [Name of Subordinated Indenture
Trustee], a banking corporation duly organized and existing under the laws of 
[                             ], as Trustee (herein called the "Trustee").

                            RECITALS OF THE COMPANY

     The Company has duly authorized the execution and delivery of this
Indenture to provide for the issuance from time to time of its unsecured
subordinated debentures, notes or other evidences of indebtedness (herein called
the "Securities"), to be issued in one or more series as in this Indenture
provided.

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

     NOW, THEREFORE, THIS INDENTURE WITNESSETH:

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

                                  ARTICLE ONE

            DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

     SECTION 101. DEFINITIONS.

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

          (1) the terms defined in this Article have the meanings assigned to
     them in this Article and include the plural as well as the singular;
     
          (2) all other terms used herein which are defined in the Trust
     Indenture Act, either directly or by reference therein, have the meanings
     assigned to them therein;
     
          (3) all accounting terms not otherwise defined herein have the
     meanings assigned to them in accordance with generally accepted accounting
     principles, and, except as otherwise herein expressly provided, the term
     "generally accepted accounting principles" with respect to any computation
     required or permitted hereunder shall mean such accounting principles as
     are generally accepted at the date of such computation;
                            -------------------------------
     
          (4) unless the context otherwise requires, any reference to an
     "Article" or a "Section" refers to an Article or a Section, as the case may
     be, of this Indenture; and
<PAGE>
 
          (5) the words "herein", "hereof" and "hereunder" and other words of
     similar import refer to this Indenture as a whole and not to any particular
     Article, Section or other subdivision.
     
     "Act", when used with respect to any Holder, has the meaning specified in
Section 104.

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

     "Authenticating Agent" means any Person authorized by the Trustee pursuant
to Section 614 to act on behalf of the Trustee to authenticate Securities of one
or more series.

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

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

     "Business Day", when used with respect to any Place of Payment, means each
Monday, Tuesday, Wednesday, Thursday and Friday which is not a day on which
banking institutions in that Place of Payment are authorized or obligated by law
or executive order to close.

     "Capital Stock" means, with respect to any Person, any and all shares,
interests, participations, rights in or other equivalents in the equity
interests (however designated) in such Person, and any rights (other than debt
securities convertible into an equity interest), warrants or options exercisable
for, exchangeable for or convertible into such an equity interest in such
Person.

     "Capitalized Lease Obligation" means any obligation to pay rent or other
amounts under a lease of (or other agreement conveying the right to use) any
property (whether real, person or mixed) that is required to be classified and
accounted for as a capital lease obligation under generally accepted accounting
principles.

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

     "Common Securities" means undivided beneficial interests in the assets of
the Nuevo Trust which rank pari passu with Preferred Securities issued by the
Nuevo Trust; provided, however, that upon the occurrence of an Event of Default,
             --------  -------
the rights of holders of Common Securities to payment in respect to
distributions and payments upon 

                                      -2-
<PAGE>
 
liquidation, redemption and otherwise are subordinated to the rights of holders
of Preferred Securities.

     "Common Securities Guarantee" means any Guarantee that the Company enters
into with [Guaranty Trustee] or other Persons that operates directly or
indirectly for the benefit of holders of Common Securities of the Nuevo Trust.

     "Common Stock" includes any shares or stock of any class of the Company
which has no preference in respect of dividends or of amounts payable in the
event of any voluntary or involuntary liquidation, dissolution or winding up of
the Company and which is not subject to redemption by the Company. Subject to
the anti-dilution provisions of any convertible Security, however, shares of
Common Stock of the Company issuable on conversion of a Security shall include
only shares of the class designated as Common Stock of the Company at the date
of any supplemental indenture, Board Resolution or other instrument authorizing
such Security or shares of any class of classes resulting from any
reclassification or reclassifications thereof and which have no preference in
respect of the payment of dividends or the distribution of assets upon any
voluntary or involuntary liquidation, dissolution or winding-up of the Company
and which are not subject to redemption by the Company, provided that if at any
time there shall be more than one such resulting class, the shares of each such
class then so issuable shall be substantially in the proportion which the total
number of shares of such class resulting from all such reclassifications bears
to the total number of shares of such classes resulting from all such
reclassifications.

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

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

     "Corporate Trust Office" means the designated office of the Trustee in
[                ], [               ] at which at any particular time its
corporate trust business shall be administered.

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

     "Covenant Defeasance" has the meaning specified in Section 1303.

     "Debt" means, with respect to any Person, without duplication, (a) all
liabilities of such Person for borrowed money or for the deferred purchase price
of property or services (excluding any trade accounts payable and other accrued
current liabilities incurred in the ordinary course of business), and all
liabilities of such Person incurred in connection with any letters of credit,
bankers' acceptances or other similar credit transactions or any agreement to
purchase, redeem, exchange, convert or otherwise acquire for value any Capital
Stock of such Person, or any warrants, rights or options to acquire such Capital
Stock outstanding on the date of this Indenture or thereafter, (b) all
obligations of such Person evidenced by bonds, notes, debentures or other
similar instruments, (c) all Debt of

                                      -3-
<PAGE>
 
such Person created or arising under any conditional sale or other title
retention agreement with respect to property acquired by such Person (even if
the rights and remedies of the seller or lender under such agreement in the
event of default are limited to repossession or sale of such property), but
excluding trade accounts payable arising in the ordinary course of business, (d)
all Capitalized Lease Obligations of such Person, (e) all Debt referred to in
the preceding clauses of other Persons and all dividends of other Persons, the
payment of which is secured by (or for which the holder of such Debt has an
existing right to be secured by) any lien upon property (including, without
limitation, accounts and contract rights) owned by such Person, even though such
Person has not assumed or become liable for the payment of such Debt (the amount
of such obligation being deemed to be the lesser of the value of such property
or asset or the amount of the obligation so secured), (f) all guarantees by such
Person of Debt referred to in this definition (including, with respect to any
Production Payments and Reserve Sales, any warranties or guaranties of
production or payment by such Person with respect to such Production Payments
and Reserve Sales but excluding other contractual obligations of such Person
with respect to such Production Payments and Reserve Sales ), (g) all Redeemable
Capital Stock of such Person valued at the greater of its voluntary or
involuntary maximum fixed repurchase price plus accrued dividends and (h) all
obligations of such Person under or in respect of currency exchange contracts,
oil or natural gas price hedging arrangements and Interest Rate Protection
Obligations. For purposes hereof, the "maximum fixed repurchase price" of any
Redeemable Capital Stock which does not have a fixed repurchase price shall be
calculated in accordance with the terms of such Redeemable Capital Stock as if
such Redeemable Capital Stock were purchased on any date on which Debt shall be
required to be determined pursuant to the Indenture, and if such price is based
upon, or measured by, the fair market value of such Redeemable Capital Stock,
such fair market value shall be determined in good faith by the board of
directors of the issuer of such Redeemable Capital Stock; provided, however,
                                                          --------  -------
that if such Redeemable Capital Stock is not at the date of determination
permitted or required to be repurchased, the "maximum fixed repurchase price"
shall be the book value of such Redeemable Capital Stock. Subject to clause (f)
of the first sentence of this definition, Production Payments and Reserve Sales
shall not be deemed "Debt."

     "Declaration", with respect to the Nuevo Trust, means the Amended and
Restated Declaration of Trust of the Nuevo Trust.

     "Defaulted Interest" has the meaning specified in Section 307.

     "Defeasance" has the meaning specified in Section 1302.

     "Depositary" means, with respect to Securities of any series issuable in
whole or in part in the form of one or more Global Securities, a clearing agency
registered under the Exchange Act that is designated to act as Depositary for
such Securities as contemplated by Section 301.

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

     "Exchange Act" means the Securities Exchange Act of 1934 and any statute
successor thereto, in each case as amended from time to time.

     "Expiration Date" has the meaning specified in Section 104.

                                      -4-
<PAGE>
 
     "Global Security" means a Security that evidences all or part of the
Securities of any series and bears the legend set forth in Section 203 (or such
legend as may be specified as contemplated by Section 301 for such Securities).

     "Guarantor" means Nuevo Energy Company, a Delaware corporation, in its
capacity as guarantor under any Trust Securities Guarantees.

     "Holder" means a Person in whose name a Security is registered in the
Security Register.

     "Indenture" means this instrument as originally executed and as it may from
time to time be supplemented or amended by one or more indentures supplemental
hereto entered into pursuant to the applicable provisions hereof, including, for
all purposes of this instrument and any such supplemental indenture, the
provisions of the Trust Indenture Act that are deemed to be a part of and govern
this instrument and any such supplemental indenture, respectively.  The term
"Indenture" shall also include the terms of particular series of Securities
established as contemplated by Section 301.

     "Institutional Trustee" has the meaning set forth in the Declaration of the
Nuevo Trust.

     "Interest", when used with respect to an Original Issue Discount Security
which by its terms bears interest only after Maturity, means interest payable
after Maturity.

     "Interest Payment Date", when used with respect to any Security, means the
Stated Maturity of an installment of interest on such Security.

     "Interest Rate Protection Obligations" means the obligations of any Person
pursuant to any arrangement with any other Person whereby,  directly or
indirectly, such Person is entitled to receive from time to time periodic
payments calculated by applying either a floating or a fixed rate of interest on
a stated notional amount in exchange for periodic payments made by such Person
calculated by applying a fixed or a floating rate of interest on the same
notional amount and shall include, without limitation, interest rate swaps,
caps, floors, collars and similar agreements or arrangements designed to protect
against or manage such Person's and any of its Subsidiaries' exposure to
fluctuations in interest rates.

     "Investment Company Act" means the Investment Company Act of 1940 and any
statute successor thereto, in each case as amended from time to time.

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

     "Notice of Default" means a written notice of the kind specified in Section
501(5).

     "Nuevo Trust" means Nuevo Financing I, a Delaware statutory business trust.

     "Officers' Certificate" means a certificate signed by the Chairman of the
Board, a Vice Chairman of the Board, the President or a Vice President, and by
the Treasurer, an 

                                      -5-
<PAGE>
 
Assistant Treasurer, the Secretary or an Assistant Secretary, of the Company,
and delivered to the Trustee. One of the officers signing an Officers'
Certificate given pursuant to Section 1004 shall be the principal executive,
financial or accounting officer of the Company.

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

     "Original Issue Discount Security" means any Security which provides for an
amount less than the principal amount thereof to be due and payable upon a
declaration of acceleration of the Maturity thereof pursuant to Section 502.

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

          (1) Securities theretofore canceled by the Trustee or delivered to the
     Trustee for cancellation;

          (2) Securities for whose payment or redemption money in the necessary
     amount has been theretofore deposited with the Trustee or any Paying Agent
     (other than the Company) in trust or set aside and segregated in trust by
     the Company (if the Company shall act as its own Paying Agent) for the
     Holders of such Securities; provided that, if such Securities are to be
     redeemed, notice of such redemption has been duly given pursuant to this
     Indenture or provision therefor satisfactory to the Trustee has been made;

          (3) Securities as to which Defeasance has been effected pursuant to
     Section 1302; and

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

provided, however, that in determining whether the Holders of the requisite
--------  -------
principal amount of the Outstanding Securities have given, made or taken any
request, demand, authorization, direction, notice, consent, waiver or other
action hereunder as of any date, (A) the principal amount of an Original Issue
Discount Security which shall be deemed to be Outstanding shall be the amount of
the principal thereof which would be due and payable as of such date upon
acceleration of the Maturity thereof to such date pursuant to Section 502, (B)
if, as of such date, the principal amount payable at the Stated Maturity of a
Security is not determinable, the principal amount of such Security which shall
be deemed to be Outstanding shall be the amount as specified or determined as
contemplated by Section 301, (C) the principal amount of a Security denominated
in one or more foreign currencies or currency units which shall be deemed to be
Outstanding shall be the U.S. dollar equivalent, determined as of such date in
the manner provided as contemplated by Section 301, of the principal amount of
such Security (or, in the case of a Security described in Clause (A) or (B)
above, of the amount determined as provided in such 

                                      -6-
<PAGE>
 
Clause), and (D) Securities owned by the Company or any other obligor upon the
Securities or any Affiliate of the Company or of such other obligor shall be
disregarded and deemed not to be Outstanding, except that, in determining
whether the Trustee shall be protected in relying upon any such request, demand,
authorization, direction, notice, consent, waiver or other action, only
Securities which the Trustee actually knows to be so owned shall be so
disregarded. Securities so owned which have been pledged in good faith may be
regarded as Outstanding if the pledgee establishes to the satisfaction of the
Trustee the pledgee's right so to act with respect to such Securities and that
the pledgee is not the Company or any other obligor upon the Securities or any
Affiliate of the Company or of such other obligor.

     "Paying Agent" means any Person authorized by the Company to pay the
principal of or any premium or interest on any Securities on behalf of the
Company.

     "Person" means any individual, corporation, bank, partnership, joint
venture, trust, unincorporated organization or government or any agency or
political subdivision thereof.

     "Place of Payment", when used with respect to the Securities of any series,
means the place or places where the principal of and any premium and interest on
the Securities of that series are payable as specified as contemplated by
Section 301.

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

     "Preferred Securities" means undivided beneficial interests in the assets
of the Nuevo Trust which rank pari passu with Common Securities issued by the
Nuevo Trust; provided, however, that upon the occurrence of an Event of Default,
             --------  -------
the rights of holders of Common Securities to payment in respect to
distributions and payments upon liquidation, redemption and otherwise are
subordinated to the rights of holders of Preferred Securities.

     "Preferred Securities Guarantee" means any Guarantee that the Guarantor may
enter into with [Guaranty Trustee] or other Persons that operates directly or
indirectly for the benefit of holders of Preferred Securities of the Nuevo
Trust.

     "Production Payments and Reserve Sales" means the grant or transfer to any
Person of a royalty, overriding royalty, net profits interest, production
payment (whether volumetric or dollar denominated), master limited partnership
interest or other interest in oil and gas properties, reserves or the right to
receive all or a portion of the production or the proceeds from the sale of
production attributable to such properties where the holder of such interest has
recourse solely to such production or proceeds of production, subject to the
obligation of the grantor or transferor to operate and maintain, or cause the
subject interest to be operated and maintained, in a reasonably prudent manner
or other customary standard or subject to the obligation of the grantor or
transferor to indemnify for environmental matters.

                                      -7-
<PAGE>
 
     "Redeemable Capital Stock" means any Capital Stock that, either by its
terms, by the terms of any security into which it is convertible or exchangeable
or by contract or otherwise, is, or upon the happening of an event or passage of
time would be, required to be redeemed prior to the final date specified in the
Securities as the Stated Maturity or is redeemable at the option of the holder
thereof at any time prior to such final Stated Maturity, or is convertible into
or exchangeable for debt securities at any time prior to such final Stated
Maturity.

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

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

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

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

     "Securities" has the meaning stated in the first recital of this Indenture
and more particularly means any Securities authenticated and delivered under
this Indenture.

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

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

     "Senior Indebtedness" means the principal of (and premium, if any) and
interest, if any (including interest accruing on or after the filing of any
petition in bankruptcy or for reorganization relating to the Company to the
extent that such claim for post-petition interest is allowed in such
proceeding), on any Debt of the Company, whether incurred on or prior to the
date of this Indenture or thereafter incurred, unless in the instrument creating
or evidencing the same or pursuant to which the same is outstanding, it is
provided that such obligations are not superior in right or payment to the
Securities, or to other Debt of the Company which is pari passu with, or
subordinated to the Securities; provided, however, that Senior Indebtedness
                                --------  -------
shall not be deemed to include the Securities or any Debt of the Company to any
Subsidiary of the Company.

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

                                      -8-
<PAGE>
 
     "Stated Maturity", when used with respect to any Security or any
installment of principal thereof or interest thereon, means the date specified
in such Security as the fixed date on which the principal of such Security or
such installment of principal or interest is due and payable.

     "Subsidiary" of any Person means (i) a corporation more than 50% of the
combined voting power of the outstanding voting stock of which is owned,
directly or indirectly, by such Person or by one or more other Subsidiaries of
such Person or by such Person and one or more Subsidiaries thereof or (ii) any
other Person (other than a corporation) in which such Person, or one or more
other Subsidiaries of such Person or such Person and one or more other
Subsidiaries thereof, directly or indirectly, have at least a majority ownership
and power to direct the policies, management and affairs thereof.  For the
purposes of this definition, "voting stock" means stock which ordinarily has
voting power for the election of directors, whether at all times or only so long
as no senior class of stock has such voting power by reason of any contingency.

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

     "Trust Securities" means Common Securities and Preferred Securities of the
Nuevo Trust.

     "Trust Securities Guarantees" means the Common Securities Guarantee and the
Preferred Securities Guarantee.

     "Trustee" means the Person named as the "Trustee" in the first paragraph of
this instrument until a successor Trustee shall have become such pursuant to the
applicable provisions of this Indenture, and thereafter "Trustee" shall mean or
include each Person who is then a Trustee hereunder, and if at any time there is
more than one such Person, "Trustee" as used with respect to the Securities of
any series shall mean the Trustee with respect to Securities of that series.

     "U.S. Government Obligation" has the meaning specified in Section 1304.

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

     SECTION 102.  COMPLIANCE CERTIFICATES AND OPINIONS.

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

                                      -9-
<PAGE>
 
     Every certificate or opinion with respect to compliance with a condition or
covenant provided for in this Indenture (except for certificates provided for in
Section 1004) shall include:

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

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

          (3) a statement that, in the opinion of each such individual, he has
     made such examination or investigation as is necessary to enable him to
     express an informed opinion as to whether or not such covenant or condition
     has been complied with; and

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

     SECTION 103.  FORM OF DOCUMENTS DELIVERED TO TRUSTEE.

     In any case where several matters are required to be certified by, or
covered by an opinion of, any specified Person, it is not necessary that all
such matters be certified by, or covered by the opinion of, only one such
Person, or that they be so certified or covered by only one document, but one
such Person may certify or give an opinion with respect to some matters and one
or more other such Persons as to other matters, and any such Person may certify
or give an opinion as to such matters in one or several documents.

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

     Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Indenture, they may, but need not, be consolidated and
form one instrument.

     SECTION 104.  ACTS OF HOLDERS; RECORD DATES.

     Any request, demand, authorization, direction, notice, consent, waiver or
other action provided or permitted by this Indenture to be given, made or taken
by Holders may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Holders in person or by agent duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly 

                                      -10-
<PAGE>
 
required, to the Company. Such instrument or instruments (and the action
embodied therein and evidenced thereby) are herein sometimes referred to as the
"Act" of the Holders signing such instrument or instruments. Proof of execution
of any such instrument or of a writing appointing any such agent shall be
sufficient for any purpose of this Indenture and (subject to Section 601)
conclusive in favor of the Trustee and the Company, if made in the manner
provided in this Section.

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

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

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

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

     The Trustee may set any day as a record date for the purpose of determining
the Holders of Outstanding Securities of any series entitled to join in the
giving or making of 

                                      -11-
<PAGE>
 
(1) any Notice of Default, (2) any declaration of acceleration referred to in
Section 502, (3) any request to institute proceedings referred to in Section
507(2) or (4) any direction referred to in Section 512, in each case with
respect to Securities of such series. If any record date is set pursuant to this
paragraph, the Holders of Outstanding Securities of such series on such record
date, and no other Holders, shall be entitled to join in such notice,
declaration, request or direction, whether or not such Holders remain Holders
after such record date; provided that no such action shall be effective
hereunder unless taken on or prior to the applicable Expiration Date by Holders
of the requisite principal amount of Outstanding Securities of such series on
such record date. Nothing in this paragraph shall be construed to prevent the
Trustee from setting a new record date for any action for which a record date
has previously been set pursuant to this paragraph (whereupon the record date
previously set shall automatically and with no action by any Person be canceled
and of no effect), and nothing in this paragraph shall be construed to render
ineffective any action taken by Holders of the requisite principal amount of
Outstanding Securities of the relevant series on the date such action is taken.
Promptly after any record date is set pursuant to this paragraph, the Trustee,
at the Company's expense, shall cause notice of such record date, the proposed
action by Holders and the applicable Expiration Date to be given to the Company
in writing and to each Holder of Securities of the relevant series in the manner
set forth in Section 106.

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

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

     SECTION 105.  NOTICES, ETC., TO TRUSTEE AND COMPANY.

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

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

          (2) the Company by the Trustee or by any Holder shall be sufficient
     for every purpose hereunder (unless otherwise herein expressly provided) if
     in writing 

                                      -12-
<PAGE>
 
     and mailed, first-class postage prepaid, to the Company addressed to it at
     the address of its principal office specified in the first paragraph of
     this instrument or at any other address previously furnished in writing to
     the Trustee by the Company.

     SECTION 106.  NOTICE TO HOLDERS; WAIVER.

     Where this Indenture provides for notice to Holders of any event, such
notice shall be sufficiently given (unless otherwise herein expressly provided)
if in writing and mailed, first-class postage prepaid, to each Holder affected
by such event, at his address as it appears in the Security Register, not later
than the latest date (if any), and not earlier than the earliest date (if any),
prescribed for the giving of such notice.  In any case where notice to Holders
is given by mail, neither the failure to mail such notice, nor any defect in any
notice so mailed, to any particular Holder shall affect the sufficiency of such
notice with respect to other Holders. Where this Indenture provides for notice
in any manner, such notice may be waived in writing by the Person entitled to
receive such notice, either before or after the event, and such waiver shall be
the equivalent of such notice.  Waivers of notice by Holders shall be filed with
the Trustee, but such filing shall not be a condition precedent to the validity
of any action taken in reliance upon such waiver.

     In case by reason of the suspension of regular mail service or by reason of
any other cause it shall be impracticable to give such notice by mail, then such
notification as shall be made with the approval of the Trustee shall constitute
a sufficient notification for every purpose hereunder.

     SECTION 107.  CONFLICT WITH TRUST INDENTURE ACT.

     If any provision hereof limits, qualifies or conflicts with a provision of
the Trust Indenture Act which is required under such Act to be a part of and
govern this Indenture, the latter provision shall control.  If any provision of
this Indenture modifies or excludes any provision of the Trust Indenture Act
which may be so modified or excluded, the latter provision shall be deemed to
apply to this Indenture as so modified or to be excluded, as the case may be.

     SECTION 108.  EFFECT OF HEADINGS AND TABLE OF CONTENTS.

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

     SECTION 109.  SUCCESSORS AND ASSIGNS.

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

     SECTION 110.  SEPARABILITY CLAUSE.

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

     SECTION 111.  BENEFITS OF INDENTURE.

                                      -13-
<PAGE>
 
     Nothing in this Indenture or in the Securities, express or implied, shall
give to any Person, other than the parties hereto and their successors hereunder
and the Holders, any benefit or any legal or equitable right, remedy or claim
under this Indenture.

     SECTION 112.  GOVERNING LAW.

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

     SECTION 113.  LEGAL HOLIDAYS.

     In any case where any Interest Payment Date, Redemption Date or Stated
Maturity of any Security shall not be a Business Day at any Place of Payment,
then (notwithstanding any other provision of this Indenture or of the Securities
(other than a provision of any Security which specifically states that such
provision shall apply in lieu of this Section)) payment of interest or principal
(and premium, if any) need not be made at such Place of Payment on such date,
but may be made on the next succeeding Business Day at such Place of Payment
with the same force and effect as if made on the Interest Payment Date or
Redemption Date, or at the Stated Maturity.

                                  ARTICLE TWO

                                 SECURITY FORMS

     SECTION 201.  FORMS GENERALLY.

     The Securities of each series shall be in such form as shall be established
by or pursuant to a Board Resolution or in one or more indentures supplemental
hereto, in each case with such appropriate insertions, omissions, substitutions
and other variations as are required or permitted by this indenture, and may
have such letters, numbers or other marks of identification and such legends or
endorsements placed thereon as may be required to comply with the rules of any
securities exchange or Depositary therefor or as may, consistently herewith, be
determined by the officers executing such Securities, as evidenced by their
execution thereof. If the form of Securities of any series is established by
action taken pursuant to a Board Resolution, a copy of an appropriate record of
such action shall be certified by the Secretary or an Assistant Secretary of the
Company and delivered to the Trustee at or prior to the delivery of the Company
Order contemplated by Section 303 for the authentication and delivery of such
Securities.

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

     SECTION 202.  FORM OF TRUSTEE'S CERTIFICATE OF AUTHENTICATION.

     The Trustee's certificates of authentication shall be in substantially the
following form:

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

                                      -14-
<PAGE>
 
                              [Name of Trustee], as Trustee



                              By:__________________________________
                                    Authorized Officer

     SECTION 203.  FORM OF LEGEND FOR GLOBAL SECURITIES.

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

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

     SECTION 204.  FORM OF CONVERSION NOTICE.

     The form of conversion notice for the conversion of Securities into shares
of Common Stock or other securities of the Company shall be in substantially the
form included with the applicable form of Securities as shall be established
pursuant to Section 201 hereinabove.

     SECTION 205.  SECURITIES IN GLOBAL FORM.

     If Securities of any series are issuable as Global Securities, as specified
as contemplated by Section 301, then, notwithstanding the provisions of Section
301, any such Security shall represent such of the Outstanding Securities of
such series as shall be specified therein and may provide that it shall
represent the aggregate amount of Outstanding Securities of such series from
time to time endorsed thereon and that the aggregate amount of Outstanding
Securities of such series represented thereby may from time to time be reduced
to reflect exchanges.  Any endorsement of a Global Security to reflect the
amount, or any increase or decrease in the amount, of Outstanding Securities of
such series represented thereby shall be made by the Trustee in such manner and
upon instructions given by such Person or Persons as shall be specified therein
or in the Company Order to be delivered to the Trustee pursuant to Section 303
or Section 304.  Subject to the provisions of Section 303 and, if applicable,
Section 304, the Trustee shall deliver and redeliver any Global Security in the
manner and upon instructions given by the Person or Persons specified therein or
in the applicable Company Order.  If a Company Order pursuant to Section 303 or
304 has been, or simultaneously is, delivered, any instructions by the Company
with respect to endorsement or delivery or redelivery of a Global Security shall
be in writing but need not comply with Section 102 and need not be accompanied
by an Opinion of Counsel.

                                      -15-
<PAGE>
 
     The provisions of the last sentence of Section 303 shall apply to any
Security represented by a Global Security if such Security was never issued and
sold by the Company and the Company delivers to the Trustee the Global Security
with written instructions (which need not comply with Section 102 and need not
be accompanied by an Opinion of Counsel) with regard to the reduction in the
principal amount of Securities represented thereby, together with the written
statement contemplated by the last sentence of Section 303.

     Notwithstanding the provisions of Sections 201 and 307, unless otherwise
specified as contemplated by Section 301, payment of principal of and any
premium and interest on any Global Security shall be made to the Person or
Persons specified therein.

     Notwithstanding the provisions of Section 308 and except as provided in the
preceding paragraph, the Company, the Trustee and any agent of the Company and
the Trustee shall treat a Person as the Holder of such principal amount of
Outstanding Securities represented by a Global Security as shall be specified in
a written statement of the Holder of such Global Security.

                                 ARTICLE THREE

                                 THE SECURITIES

     SECTION 301.  AMOUNT UNLIMITED; ISSUABLE IN SERIES.

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

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

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

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

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

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

                                      -16-
<PAGE>
 
          (5) the rate or rates at which any Securities of the series shall bear
     interest, if any, the date or dates from which any such interest shall
     accrue, the Interest Payment Dates on which any such interest shall be
     payable and the Regular Record Date for any such interest payable on any
     Interest Payment Date;

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

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

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

          (9) the right, if any, to extend the interest payment periods in
     respect of the Securities of the series and the duration of such extension;

          (10) the terms of any right to convert or exchange Securities of the
     series, either at the election of the Holder thereof or the Company, into
     or for shares of Common Stock of the Company or other securities or
     property, including, without limitation, the period or periods within which
     and the price or prices (including adjustments thereto) at which any
     Securities of the series shall be converted or exchanged, in whole or in
     part and any other provision in addition to or in lieu of those set forth
     in this Indenture;

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

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

          (13) if other than the currency of the United States of America, the
     currency, currencies or currency units in which the principal of or any
     premium or interest on any Securities of the series shall be payable and
     the manner of determining the equivalent thereof in the currency of the
     United States of America for any purpose, including for purposes of the
     definition of "Outstanding" in Section 101;

          (14) if the principal of or any premium or interest on any Securities
     of the series is to be payable, at the election of the Company or the
     Holder thereof, in one or more currencies or currency units other than that
     or those in which such Securities are stated to be payable, the currency,
     currencies or currency units in 

                                      -17-
<PAGE>
 
     which the principal of or any premium or interest on such Securities as to
     which such election is made shall be payable, the periods within which and
     the terms and conditions upon which such election is to be made and the
     amount so payable (or the manner in which such amount shall be determined);

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

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

          (17) if applicable, that the Securities of the series, in whole or any
     specified part, shall be defeasible pursuant to Section 1302 or Section
     1303 or both such Sections and, if other than by a Board Resolution, the
     manner in which any election by the Company to defease such Securities
     shall be evidenced;

          (18) if applicable, that any Securities of the series shall be
     issuable in whole or in part in the form of one or more Global Securities
     and, in such case, the respective Depositaries for such Global Securities,
     the form of any legend or legends which shall be borne by any such Global
     Security in addition to or in lieu of that set forth in Section 203 and any
     circumstances in addition to or in lieu of those set forth in Clause (2) of
     the last paragraph of Section 305 in which any such Global Security may be
     exchanged in whole or in part for Securities registered, and any transfer
     of such Global Security in whole or in part may be registered, in the name
     or names of Persons other than the Depositary for such Global Security or a
     nominee thereof;

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

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

          (21) any restriction or condition on the transferability of the
     Securities;

          (22) the subordination terms of the Securities of the series; and

          (23) any other terms of the series (which terms shall not be
     inconsistent with the provisions of this Indenture, except as permitted by
     Section 901(5)).

                                      -18-
<PAGE>
 
     All Securities of any one series shall be substantially identical except as
to denomination and except as may otherwise be provided in or pursuant to the
Board Resolution referred to above and (subject to Section 303) set forth, or
determined in the manner provided, in the Officers' Certificate referred to
above or in any such indenture supplemental hereto.

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

     SECTION 302.  DENOMINATIONS.

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

     SECTION 303.  EXECUTION, AUTHENTICATION, DELIVERY AND DATING.

     The Securities shall be executed on behalf of the Company by its Chairman
of the Board, its Vice Chairman of the Board, its President or one of its Vice
Presidents, under its corporate seal reproduced thereon attested by its
Secretary or one of its Assistant Secretaries.  The signature of any of these
officers on the Securities may be manual or facsimile.

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

     At any time and from time to time after the execution and delivery of this
Indenture, the Company may deliver Securities of any series executed by the
Company to the Trustee for authentication, together with a Company Order for the
authentication and delivery of such Securities, and the Trustee in accordance
with the Company Order shall authenticate and deliver such Securities.  If the
form or terms of the Securities of the series have been established by or
pursuant to one or more Board Resolutions as permitted by Sections 201 and 301,
prior to authenticating such Securities, and accepting the additional
responsibilities under this Indenture in relation to such Securities, the
Trustee shall be entitled to receive, and (subject to Section 601) shall be
fully protected in relying upon, an Opinion of Counsel stating,

          (1) if the form of such Securities has been established by or pursuant
     to Board Resolution as permitted by Section 201, that such form has been
     established in conformity with the provisions of this Indenture;

          (2) if the terms of such Securities have been established by or
     pursuant to Board Resolution as permitted by Section 301, that such terms
     have been established in conformity with the provisions of this Indenture;
     and

                                      -19-
<PAGE>
 
          (3) that such Securities, when authenticated and delivered by the
     Trustee and issued by the Company in the manner and subject to any
     conditions specified in such Opinion of Counsel, will constitute valid and
     legally binding obligations of the Company enforceable in accordance with
     their terms, subject to bankruptcy, insolvency, fraudulent transfer,
     reorganization, moratorium and similar laws of general applicability
     relating to or affecting creditors' rights and to general equity
     principles.

If such form or terms have been so established, the Trustee shall not be
required to authenticate such Securities if the issue of such Securities
pursuant to this Indenture will affect the Trustee's own rights, duties or
immunities under the Securities and this Indenture or otherwise in a manner
which is not reasonably acceptable to the Trustee.

     Notwithstanding the provisions of Section 301 and of the preceding
paragraph, if all Securities of a series are not to be originally issued at one
time, it shall not be necessary to deliver the Officers' Certificate otherwise
required pursuant to Section 301 or the Company Order and Opinion of Counsel
otherwise required pursuant to such preceding paragraph at or prior to the
authentication of each Security of such series if such documents are delivered
at or prior to the authentication upon original issuance of the first Security
of such series to be issued.

     Each Security shall be dated the date of its authentication.

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

     SECTION 304.  TEMPORARY SECURITIES.

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

     If temporary Securities of any series are issued, the Company will cause
definitive Securities of that series to be prepared without unreasonable delay.
After the preparation of definitive Securities of such series, the temporary
Securities of such series shall be exchangeable for definitive Securities of
such series upon surrender of the temporary Securities of such series at the
office or agency of the Company in a Place of Payment for that series, without
charge to the Holder.  Upon surrender for cancellation of any one or 

                                      -20-
<PAGE>
 
more temporary Securities of any series, the Company shall execute and the
Trustee shall authenticate and deliver in exchange therefor one or more
definitive Securities of the same series, of any authorized denominations and of
like tenor and aggregate principal amount. Until so exchanged, the temporary
Securities of any series shall in all respects be entitled to the same benefits
under this Indenture as definitive Securities of such series and tenor.

     SECTION 305.  REGISTRATION, REGISTRATION OF TRANSFER AND EXCHANGE.

     The Company shall cause to be kept at the Corporate Trust Office of the
Trustee a register (the register maintained in such office and in any other
office or agency of the Company in a Place of Payment being herein sometimes
collectively referred to as the "Security Register") in which, subject to such
reasonable regulations as it may prescribe, the Company shall provide for the
registration of Securities and of transfers of Securities.  The Trustee is
hereby appointed "Security Registrar" for the purpose of registering Securities
and transfers of Securities as herein provided.  The Security Registrar shall be
entitled to the rights and protections extended to the Trustee hereunder.

     Upon surrender for registration of transfer of any Security of a series at
the office or agency of the Company in a Place of Payment for that series, the
Company shall execute, and the Trustee shall authenticate and deliver, in the
name of the designated transferee or transferees, one or more new Securities of
the same series, of any authorized denominations and of like tenor and aggregate
principal amount.

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

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

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

     No service charge shall be made for any registration of transfer or
exchange of Securities, but the Company may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection
with any registration of transfer or exchange of Securities, other than
exchanges pursuant to Section 304, 906 or 1107 not involving any transfer.

     If the Securities of any series (or of any series and specified tenor) are
to be redeemed in part, the Company shall not be required (A) to issue, register
the transfer of or exchange any Securities of that series (or of that series and
specified tenor, as the case may be) during a period beginning at the opening of
business 15 days before the day of the mailing of a notice of redemption of any
such Securities selected for redemption under 

                                      -21-
<PAGE>
 
Section 1103 and ending at the close of business on the day of such mailing, or
(B) to register the transfer of or exchange any Security so selected for
redemption in whole or in part, except the unredeemed portion of any Security
being redeemed in part.

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

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

          (2) Notwithstanding any other provision in this Indenture, no Global
     Security may be exchanged in whole or in part for Securities registered,
     and no transfer of a Global Security in whole or in part may be registered,
     in the name of any Person other than the Depositary for such Global
     Security or a nominee thereof unless (A) such Depositary (i) has notified
     the Company that it is unwilling or unable to continue as Depositary for
     such Global Security or (ii) has ceased to be a clearing agency registered
     under the Exchange Act, (B) there shall have occurred and be continuing an
     Event of Default with respect to such Global Security or (C) there shall
     exist such circumstances, if any, in addition to or in lieu of the
     foregoing as have been specified for this purpose as contemplated by
     Section 301.

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

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

     SECTION 306.  MUTILATED, DESTROYED, LOST AND STOLEN SECURITIES.

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

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

                                      -22-
<PAGE>
 
     In case any such mutilated, destroyed, lost or stolen Security has become
or is about to become due and payable, the Company in its discretion may,
instead of issuing a new Security, pay such Security.

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

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

     The provisions of this Section are exclusive and shall preclude (to the
extent lawful) all other rights and remedies with respect to the replacement or
payment of mutilated, destroyed, lost or stolen Securities.

     SECTION 307.  PAYMENT OF INTEREST; INTEREST RIGHTS PRESERVED.

     Except as otherwise provided as contemplated by Section 301 with respect to
any series of Securities, interest on any Security which is payable, and is
punctually paid or duly provided for, on any Interest Payment Date shall be paid
to the Person in whose name that Security (or one or more Predecessor
Securities) is registered at the close of business on the Regular Record Date
for such interest.

     Any interest on any Security of any series which is payable, but is not
punctually paid or duly provided for, on any Interest Payment Date (herein
called "Defaulted Interest") shall forthwith cease to be payable to the Holder
on the relevant Regular Record Date by virtue of having been such Holder, and
such Defaulted Interest may be paid by the Company, at its election in each
case, as provided in Clause (1) or (2) below:

          (1) The Company may elect to make payment of any Defaulted Interest to
     the Persons in whose names the Securities of such series (or their
     respective Predecessor Securities) are registered at the close of business
     on a Special Record Date for the payment of such Defaulted Interest, which
     shall be fixed in the following manner.  The Company shall notify the
     Trustee in writing of the amount of Defaulted Interest proposed to be paid
     on each Security of such series and the date of the proposed payment, and
     at the same time the Company shall deposit with the Trustee an amount of
     money equal to the aggregate amount proposed to be paid in respect of such
     Defaulted Interest or shall make arrangements satisfactory to the Trustee
     for such deposit prior to the date of the proposed payment, such money when
     deposited to be held in trust for the benefit of the Persons entitled to
     such Defaulted Interest as in this Clause provided.  Thereupon the Trustee
     shall fix a Special Record Date for the payment of such Defaulted Interest
     which shall be not more than 15 days and not less than 10 days prior to the
     date of the proposed payment and not less than 10 days after the receipt by
     the Trustee of the notice of the proposed payment.  The Trustee shall
     promptly notify the Company of such 

                                      -23-
<PAGE>
 
     Special Record Date and, in the name and at the expense of the Company,
     shall cause notice of the proposed payment of such Defaulted Interest and
     the Special Record Date therefor to be given to each Holder of Securities
     of such series in the manner set forth in Section 106, not less than 10
     days prior to such Special Record Date. Notice of the proposed payment of
     such Defaulted Interest and the Special Record Date therefor having been so
     mailed, such Defaulted Interest shall be paid to the Persons in whose names
     the Securities of such series (or their respective Predecessor Securities)
     are registered at the close of business on such Special Record Date and
     shall no longer be payable pursuant to the following Clause (2).

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

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

     In the case of any Security which is converted into Common Stock of the
Company after any Regular Record Date and on or prior to the next succeeding
Interest Payment Date (other than any Security whose Maturity is prior to such
Interest Payment Date), interest whose Stated Maturity is on such Interest
Payment Date shall be payable on such Interest Payment Date notwithstanding such
conversion, and such interest (whether or not punctually paid or duly provided
for) shall be paid to the Person in whose name that Security (or one or more
Predecessor Securities) is registered at the close of business on such Regular
Record Date. Except as otherwise expressly provided in the immediately preceding
sentence, in the case of any Security which is converted, interest whose Stated
Maturity is after the date of conversion of such Security shall not be payable.

     SECTION 308.  PERSONS DEEMED OWNERS.

     Prior to due presentment of a Security for registration of transfer, the
Company, the Trustee and any agent of the Company or the Trustee may treat the
Person in whose name such Security is registered as the owner of such Security
for the purpose of receiving payment of principal of and any premium and
(subject to Section 307) any interest on such Security and for all other
purposes whatsoever, whether or not such Security be overdue, and neither the
Company, the Trustee nor any agent of the Company or the Trustee shall be
affected by notice to the contrary.

     SECTION 309.  CANCELLATION.

     All Securities surrendered for payment, redemption, registration of
transfer or exchange or for credit against any sinking fund payment shall, if
surrendered to any Person other than the Trustee, be delivered to the Trustee
and shall be promptly canceled by it.  The Company may at any time deliver to
the Trustee for cancellation any Securities previously authenticated and
delivered hereunder which the Company may have acquired in any manner
whatsoever, and may deliver to the Trustee (or to any other Person for 

                                      -24-
<PAGE>
 
delivery to the Trustee) for cancellation any Securities previously
authenticated hereunder which the Company has not issued and sold, and all
Securities so delivered shall be promptly canceled by the Trustee. No Securities
shall be authenticated in lieu of or in exchange for any Securities canceled as
provided in this Section, except as expressly permitted by this Indenture. All
canceled Securities held by the Trustee shall be disposed of as directed by a
Company Order.

     SECTION 310.  COMPUTATION OF INTEREST.

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

                                  ARTICLE FOUR

                           SATISFACTION AND DISCHARGE

     SECTION 401.  SATISFACTION AND DISCHARGE OF INDENTURE.

     This Indenture shall upon Company Request cease to be of further effect
(except as to any surviving rights of registration of transfer or exchange of
Securities herein expressly provided for), and the Trustee, at the expense of
the Company, shall execute proper instruments acknowledging satisfaction and
discharge of this Indenture, when either (A) all Securities theretofore
authenticated and delivered (other than (i) Securities which have been
destroyed, lost or stolen and which have been replaced or paid as provided in
Section 306 and (ii) Securities for whose payment money has theretofore been
deposited in trust or segregated and held in trust by the Company and thereafter
repaid to the Company or discharged from such trust, as provided in Section
1003) have been delivered to the Trustee for cancellation; or (B) all such
Securities not theretofore delivered to the Trustee for cancellation (i) have
become due and payable, or (ii) will become due and payable at their Stated
Maturity within one year, or (iii) are to be called for redemption within one
year under arrangements satisfactory to the Trustee for the giving of notice of
redemption by the Trustee in the name, and at the expense, of the Company, and
the Company, in the case of (i), (ii) or (iii) above, has deposited or caused to
be deposited with the Trustee as trust funds in trust for the purpose money in
an amount sufficient to pay and discharge the entire indebtedness on such
Securities not theretofore delivered to the Trustee for cancellation, for
principal and any premium and interest to the date of such deposit (in the case
of Securities which have become due and payable) or to the Stated Maturity or
Redemption Date, as the case may be;

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

          (3) the Company has delivered to the Trustee an Officers' Certificate
     and an Opinion of Counsel, each stating that all conditions precedent
     herein provided for relating to the satisfaction and discharge of this
     Indenture have been complied with.

     Notwithstanding the satisfaction and discharge of this Indenture, the
rights of the Trustee under Sections 507(3), 601 and 603, the obligations of the
Company to the Trustee under Section 607, the obligations of the Trustee to any
Authenticating Agent 

                                      -25-
<PAGE>
 
under Section 614 and, if money shall have been deposited with the Trustee
pursuant to subclause (B) of Clause (l) of this Section, the obligations of the
Trustee under Section 402 and the last paragraph of Section 1003 shall survive.

     SECTION 402.  APPLICATION OF TRUST MONEY.

     Subject to the provisions of the last paragraph of Section 1003, all money
deposited with the Trustee pursuant to Section 401 shall be held in trust and
applied by it, in accordance with the provisions of the Securities and this
Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the Persons entitled thereto, of the principal and any premium and
interest for whose payment such money has been deposited with the Trustee.
Money deposited pursuant to this Section not in violation of this Indenture
shall not be subject to claims of the holders of Senior Indebtedness under
Article Fifteen hereof.

                                  ARTICLE FIVE

                                   REMEDIES

     SECTION 501.  EVENTS OF DEFAULT.

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

          (1) default in the payment of any interest upon any Security of that
     series when it becomes due and payable, and continuance of such default for
     a period of 30 days (whether or not such payment is prohibited by the
     subordination provisions set forth in Article Fifteen hereof); provided,
     however, that a valid extension of an interest payment period by the
     Company in accordance with the terms of any indenture supplemental hereto
     shall not constitute a default in the payment of interest for this purpose;
     or

          (2) default in the payment of the principal of or any premium on any
     Security of that series at its Maturity (whether or not such payment is
     prohibited by the subordination provisions set forth in Article Fifteen
     hereof); or

          (3) default in the deposit of any sinking fund payment, when and as
     due by the terms of a Security of that series; or

          (4) if the Securities of that series are convertible or exchangeable
     into or for shares of Common Stock of the Company or other securities, cash
     or other property pursuant to any supplemental indenture, Board Resolution
     or other instrument authorizing Securities of that series, failure by the
     Company to convert such Securities (whether or not such conversion or
     exchange is prohibited by the subordination provisions set forth in Article
     Fifteen hereof); or

          (5) default in the performance, or breach, of any covenant or warranty
     of the Company in this Indenture (other than a covenant or warranty a
     default in 

                                      -26-
<PAGE>
 
     whose performance or whose breach is elsewhere in this Section specifically
     dealt with or which has expressly been included in this Indenture solely
     for the benefit of series of Securities other than that series), and
     continuance of such default or breach for a period of 60 days after there
     has been given, by registered or certified mail, to the Company by the
     Trustee or to the Company and the Trustee by the Holders of at least 25% in
     principal amount of the Outstanding Securities of that series a written
     notice specifying such default or breach and requiring it to be remedied
     and stating that such notice is a "Notice of Default" hereunder; or

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

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

          (8) in the event Securities of that series are issued to the Nuevo
     Trust or a trustee of such trust in connection with the issuance of Trust
     Securities by the Nuevo Trust, the Nuevo Trust shall have voluntarily or
     involuntarily dissolved, wound-up its business or otherwise terminated its
     existence except in connection with (A) the distribution of Securities of
     that series to holders of Trust Securities in liquidation of their interest
     in the Nuevo Trust, (B) the redemption of all of the outstanding Trust
     Securities of the Nuevo Trust or (C) certain mergers, consolidations or
     amalgamations, each as permitted by the Declaration of the Nuevo Trust; or

          (9) any other Event of Default provided with respect to Securities of
     that series.

                                      -27-
<PAGE>
 
     SECTION 502.  ACCELERATION OF MATURITY; RESCISSION AND ANNULMENT.

     If an Event of Default (other than an Event of Default specified in Section
501(6) or 501(7)) with respect to Securities of any series at the time
Outstanding occurs and is continuing, then in every such case the Trustee or the
Holders of not less than 25% in principal amount of the Outstanding Securities
of that series may declare the principal amount of all the Securities of that
series (or, if any Securities of that series are Original Issue Discount
Securities, such portion of the principal amount of such Securities as may be
specified by the terms thereof) to be due and payable immediately, by a notice
in writing to the Company (and to the Trustee if given by Holders), and upon any
such declaration such principal amount (or specified amount) shall become
immediately due and payable; provided, however, that the Holders of a majority
in aggregate principal amount of Securities of such series then Outstanding may
rescind or annul such declaration and its consequences by objecting in writing
within 30 days of such declaration.  If an Event of Default specified in Section
501(6) or 501(7) with respect to Securities of any series at the time
Outstanding occurs, the principal amount of all the Securities of that series
(or, if any Securities of that series are Original Issue Discount Securities,
such portion of the principal amount of such Securities as may be specified by
the terms thereof) shall automatically, and without any declaration or other
action on the part of the Trustee or any Holder, become immediately due and
payable.

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

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

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

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

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

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

     and

          (2)  all Events of Default with respect to Securities of that series,
     other than the non-payment of the principal of Securities of that series
     which have 

                                      -28-
<PAGE>
 
     become due solely by such declaration of acceleration, have been cured or
     waived as provided in Section 513.

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

     SECTION 503.  COLLECTION OF INDEBTEDNESS AND SUITS FOR ENFORCEMENT BY
TRUSTEE.

     The Company covenants that if:

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

          (2) default is made in the payment of the principal of (or premium, if
     any, on) any Security at the Maturity thereof, the Company will, upon
     demand of the Trustee, pay to it, for the benefit of the Holders of such
     Securities, the whole amount then due and payable on such Securities for
     principal and any premium and interest and, to the extent that payment of
     such interest shall be legally enforceable, interest on any overdue
     principal and premium and on any overdue interest, at the rate or rates
     prescribed therefor in such Securities and if such Securities are held by a
     Nuevo Trust or a trustee of such trust, without duplication of any other
     amounts paid by such Nuevo Trust or trustee in respect thereof, upon
     overdue installments of interest at the rate per annum expressed in such
     Securities; and, in addition thereto, such further amount as shall be
     sufficient to cover the costs and expenses of collection, including the
     reasonable compensation, expenses, disbursements and advances of the
     Trustee, its agents and counsel.

     If an Event of Default with respect to Securities of any series occurs and
is continuing, the Trustee may in its discretion proceed to protect and enforce
its rights and the rights of the Holders of Securities of such series by such
appropriate judicial proceedings as the Trustee shall deem most effectual to
protect and enforce any such rights, whether for the specific enforcement of any
covenant or agreement in this Indenture or in aid of the exercise of any power
granted herein, or to enforce any other proper remedy.

     SECTION 504.  TRUSTEE MAY FILE PROOF OF CLAIM.

     In case of any judicial proceeding relative to the Company (or any other
obligor upon the Securities), its property or its creditors, the Trustee shall
be entitled and empowered, by intervention in such proceeding or otherwise, to
take any and all actions authorized under the Trust Indenture Act in order to
have claims of the Holders and the Trustee allowed in any such proceeding.  In
particular, the Trustee shall be authorized to collect and receive any moneys or
other property payable or deliverable on any such claims and to distribute the
same; and any custodian, receiver, assignee, trustee, liquidator, sequestrator
or other similar official in any such judicial proceeding is hereby authorized
by each Holder to make such payments to the Trustee and, in the event that the
Trustee shall consent to the making of such payments directly to the Holders, to
pay to the Trustee any amount due it for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, and any other
amounts due the Trustee under Section 607.

                                      -29-
<PAGE>
 
     No provision of this Indenture shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder any plan of
reorganization, arrangement, adjustment or composition affecting the Securities
or the rights of any Holder thereof or to authorize the Trustee to vote in
respect of the claim of any Holder in any such proceeding; provided, however,
that the Trustee may, on behalf of the Holders, vote for the election of a
trustee in bankruptcy or similar official and be a member of a creditors' or
other similar committee.

     SECTION 505.  TRUSTEE MAY ENFORCE CLAIMS WITHOUT POSSESSION OF SECURITIES.

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

     SECTION 506.  APPLICATION OF MONEY COLLECTED.

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

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

     SECOND: To the payment of all Senior Indebtedness of the Company to the
required by Article Fifteen hereof;

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

     FOURTH: To the payment of the remainder, if any, to the Company.

     SECTION 507.  LIMITATION ON SUITS.

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

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

                                      -30-
<PAGE>
 
          (2) the Holders of not less than 25% in principal amount of the
     Outstanding Securities of that series shall have made written request to
     the Trustee to institute proceedings in respect of such Event of Default in
     its own name as Trustee hereunder;

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

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

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

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

     SECTION 508.  UNCONDITIONAL RIGHT OF HOLDERS TO RECEIVE PRINCIPAL, PREMIUM
AND INTEREST.

     Notwithstanding any other provision in this Indenture, but subject to
Article Fifteen of this Indenture, the Holder of any Security shall have the
right, which is absolute and unconditional, to receive payment of the principal
of and any premium and (subject to Section 307) interest on such Security on the
respective Stated Maturities expressed in such Security (or, in the case of
redemption, on the Redemption Date) and to institute suit for the enforcement of
any such payment, and such rights shall not be impaired without the consent of
such Holder.

     SECTION 509.  RESTORATION OF RIGHTS AND REMEDIES.

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

     SECTION 510.  RIGHTS AND REMEDIES CUMULATIVE.

     Except as otherwise provided with respect to the replacement or payment of
mutilated, destroyed, lost or stolen Securities in the last paragraph of Section
306, no right or remedy herein conferred upon or reserved to the Trustee or to
the Holders is intended to be exclusive of any other right or remedy, and every
right and remedy shall, to the extent permitted by law, be cumulative and in
addition to every other right and remedy given 

                                      -31-
<PAGE>
 
hereunder or now or hereafter existing at law or in equity or otherwise. The
assertion or employment of any right or remedy hereunder, or otherwise, shall
not prevent the concurrent assertion or employment of any other appropriate
right or remedy.

     SECTION 511.  DELAY OR OMISSION NOT WAIVER.

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

     SECTION 512.  CONTROL BY HOLDERS. 

     The holders of a majority in principal amount of the Outstanding Securities
of any series shall have the right to direct the time, method and place of
conducting any proceeding for any remedy available to the Trustee, or exercising
any trust or power conferred on the Trustee, with respect to the Securities of
such series, provided that

          (1) such direction shall not be in conflict with any rule of law or
     with this Indenture,

          (2) such Holder or Holders have offered to the Trustee reasonable
     indemnity against the costs, expenses and liabilities to be incurred in
     connection therewith, and

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

     SECTION 513.  WAIVER OF PAST DEFAULTS.

     The Holders of not less than a majority in principal amount of the
Outstanding Securities of any series may on behalf of the Holders of all the
Securities of such series waive any past default hereunder with respect to such
series and its consequences, except a default:

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

          (2) in respect of a covenant or provision hereof under Article Nine
     cannot be modified or amended without the consent of the Holder of each
     Outstanding Security of such series affected;

provided, however, that if the Securities of such series are held by the Nuevo
Trust or a trustee of such trust, such waiver or modification to such waiver
shall not be effective until the holders of a majority in liquidation preference
of Trust Securities of the Nuevo Trust shall have consented to such waiver or
modification to such waiver; provided, further, that if the consent of the
Holder of each Outstanding Security of such series is required, such waiver
shall not be effective until each holder of the Trust Securities of the Nuevo
Trust shall have consented to such waiver.

                                      -32-
<PAGE>
 
     Upon any such waiver, such default shall cease to exist, and any Event of
Default arising therefrom shall be deemed to have been cured, for every purpose
of this Indenture; but no such waiver shall extend to any subsequent or other
default or impair any right consequent thereon.

     SECTION 514.  UNDERTAKING FOR COSTS. 

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

     SECTION 515.  WAIVER OF USURY, STAY OR EXTENSION LAWS.

     The Company covenants (to the extent that it may lawfully do so) that it
will not at any time insist upon, or plead, or in any manner whatsoever claim or
take the benefit or advantage of, any usury, stay or extension law wherever
enacted, now or at any time hereafter in force, which may affect the covenants
or the performance of this Indenture; and the Company (to the extent that it may
lawfully do so) hereby expressly waives all benefit or advantage of any such law
and covenants that it will not hinder, delay or impede the execution of any
power herein granted to the Trustee, but will suffer and permit the execution of
every such power as though no such law had been enacted.

                                  ARTICLE SIX

                                  THE TRUSTEE

     SECTION 601.  CERTAIN DUTIES AND RESPONSIBILITIES.

     The duties and responsibilities of the Trustee shall be as provided by the
Trust Indenture Act.  Notwithstanding the foregoing, no provision of this
Indenture shall require the Trustee to expend or risk its own funds or otherwise
incur any financial liability in the performance of any of its duties hereunder,
or in the exercise of any of its rights or powers, if it shall have reasonable
grounds for believing that repayment of such funds or adequate indemnity against
such risk or liability is not reasonably assured to it.  Whether or not therein
expressly so provided, every provision of this Indenture relating to the conduct
or affecting the liability of or affording protection to the Trustee shall be
subject to the provisions of this Section.

     SECTION 602.  NOTICE OF DEFAULTS. 

     If a default occurs hereunder with respect to Securities of any series, the
Trustee shall give the Holders of Securities of such series notice of such
default as and to the extent provided by the Trust Indenture Act; provided,
however, that in the case of any default of the character specified in Section
501(5) with respect to Securities of such series, no such notice to Holders
shall be given until at least 60 days after the occurrence thereof. For the
purpose of this Section, the term "default" means any event which is, or 

                                      -33-
<PAGE>
 
after notice or lapse of time or both would become, an event of default with
respect to securities of such series.

     SECTION 603.  CERTAIN RIGHTS OF TRUSTEE.

     Subject to the provisions of Section 601:

          (1) the Trustee may rely and shall be protected in acting or
     refraining from acting upon any resolution, certificate, statement,
     instrument, opinion, report, notice, request, direction, consent, order,
     bond, debenture, note, other evidence of indebtedness or other paper or
     document believed by it to be genuine and to have been signed or presented
     by the proper party or parties;

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

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

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

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

          (6) the Trustee shall not be bound to make any investigation into the
     facts or matters stated in any resolution, certificate, statement,
     instrument, opinion, report, notice, request, direction, consent, order,
     bond, debenture, note, other evidence of indebtedness or other paper or
     document, but the Trustee, in its discretion, may make such further inquiry
     or investigation into such facts or matters as it may see fit, and, if the
     Trustee shall determine to make such further inquiry or investigation, it
     shall be entitled to examine the books, records and premises of the
     Company, personally or by agent or attorney; and

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

     SECTION 604.  NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OF SECURITIES.

                                      -34-
<PAGE>
 
     The recitals contained herein and in the Securities, except the Trustee's
certificates of authentication, shall be taken as the statements of the Company,
and neither the Trustee nor any Authenticating Agent assumes any responsibility
for their correctness.  The Trustee makes no representations as to the validity
or sufficiency of this Indenture or of the Securities.  Neither the Trustee nor
any Authenticating Agent shall be accountable for the use or application by the
Company of Securities or the proceeds thereof.

     SECTION 605.  MAY HOLD SECURITIES.

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

     SECTION 606.  MONEY HELD IN TRUST.

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

     SECTION 607.  COMPENSATION AND REIMBURSEMENT.

     The Company agrees:

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

          (2) except as otherwise expressly provided herein, to reimburse the
     Trustee upon its request for all reasonable expenses, disbursements and
     advances incurred or made by the Trustee in accordance with any provision
     of this Indenture (including the reasonable compensation and the expenses
     and disbursements of its agents and counsel), except any such expense,
     disbursement or advance as may be attributable to its negligence or bad
     faith; and

          (3) to indemnify the Trustee for, and to hold it harmless against, any
     loss, liability or expense incurred without negligence or bad faith on its
     part, arising out of or in connection with the acceptance or administration
     of the trust or trusts hereunder, including the costs and expenses of
     defending itself against any claim or liability in connection with the
     exercise or performance of any of its powers or duties hereunder.

     SECTION 608.  CONFLICTING INTERESTS.

     If the Trustee has or shall acquire a conflicting interest within the
meaning of the Trust Indenture Act, the Trustee shall either eliminate such
interest or resign, to the extent and in the manner provided by, and subject to
the provisions of, the Trust Indenture Act and this Indenture.  To the extent
permitted by such Act, the Trustee shall not be deemed 

                                      -35-
<PAGE>
 
to have a conflicting interest by virtue of being a trustee under this Indenture
with respect to Securities of more than one series.

     SECTION 609.  CORPORATE TRUSTEE REQUIRED; ELIGIBILITY.

     There shall at all times be one (and only one) Trustee hereunder with
respect to the Securities of each series, which may be Trustee hereunder for
Securities of one or more other series.  Each Trustee shall be a Person that is
eligible pursuant to the Trust Indenture Act to act as such, has a combined
capital and surplus of at least $50,000,000.  If any such Person publishes
reports of condition at least annually, pursuant to law or to the requirements
of its supervising or examining authority, then for the purposes of this Section
and to the extent permitted by the Trust Indenture Act, the combined capital and
surplus of such Person shall be deemed to be its combined capital and surplus as
set forth in its most recent report of condition so published.  If at any time
the Trustee with respect to the Securities of any series shall cease to be
eligible in accordance with the provisions of this Section, it shall resign
immediately in the manner and with the effect hereinafter specified in this
Article.

     SECTION 610.  RESIGNATION AND REMOVAL, APPOINTMENT OF SUCCESSOR.

     No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee in accordance with the applicable
requirements of Section 611.

     The Trustee may resign at any time with respect to the Securities of one or
more series by giving written notice thereof to the Company.  If the instrument
of acceptance by a successor Trustee required by Section 611 shall not have been
delivered to the Trustee within 30 days after the giving of such notice of
resignation, the resigning Trustee may petition any court of competent
jurisdiction for the appointment of a successor Trustee with respect to the
Securities of such series.

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

     If at any time:

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

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

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

then, in any such case, (A) the Company by a Board Resolution may remove the
Trustee with respect to all Securities, or (B) subject to Section 514, any
Holder who has been a 

                                      -36-
<PAGE>
 
bona fide Holder of a Security for at least six months may, on behalf of himself
and all others similarly situated, petition any court of competent jurisdiction
for the removal of the Trustee with respect to all Securities and the
appointment of a successor Trustee or Trustees.

     If the Trustee shall resign, be removed or become incapable of acting, or
if a vacancy shall occur in the office of Trustee for any cause, with respect to
the Securities of one or more series, the Company, by a Board Resolution, shall
promptly appoint a successor Trustee or Trustees with respect to the Securities
of that or those series (it being understood that any such successor Trustee may
be appointed with respect to the Securities of one or more or all of such series
and that at any time there shall be only one Trustee with respect to the
Securities of any particular series) and shall comply with the applicable
requirements of Section 611.  If, within one year after such resignation,
removal or incapability, or the occurrence of such vacancy, a successor Trustee
with respect to the Securities of any series shall be appointed by Act of the
Holders of a majority in principal amount of the Outstanding Securities of such
series delivered to the Company and the retiring Trustee, the successor Trustee
so appointed shall, forthwith upon its acceptance of such appointment in
accordance with the applicable requirements of Section 611, become the successor
Trustee with respect to the Securities of such series and to that extent
supersede the successor Trustee appointed by the Company.  If no successor
Trustee with respect to the Securities of any series shall have been so
appointed by the Company or the Holders and accepted appointment in the manner
required by Section 611, any Holder who has been a bona fide Holder of a
Security of such series for at least six months may, on behalf of himself and
all others similarly situated, petition any court of competent jurisdiction for
the appointment of a successor Trustee with respect to the Securities of such
series.

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

     SECTION 611.  ACCEPTANCE OF APPOINTMENT BY SUCCESSOR.

     In case of the appointment hereunder of a successor Trustee with respect to
all Securities, every such successor Trustee so appointed shall execute,
acknowledge and deliver to the Company and to the retiring Trustee an instrument
accepting such appointment, and thereupon the resignation or removal of the
retiring Trustee shall become effective and such successor Trustee, without any
further act, deed or conveyance, shall become vested with all the rights,
powers, trusts and duties of the retiring Trustee; but, on the request of the
Company or the successor Trustee, such retiring Trustee shall, upon payment of
its charges, execute and deliver an instrument transferring to such successor
Trustee all the rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all property and money
held by such retiring Trustee hereunder.

     In case of the appointment hereunder of a successor Trustee with respect to
the Securities of one or more (but not all) series, the Company, the retiring
Trustee and each successor Trustee with respect to the Securities of one or more
series shall execute and 

                                      -37-
<PAGE>
 
deliver an indenture supplemental hereto wherein each successor Trustee shall
accept such appointment and which (1) shall contain such provisions as shall be
necessary or desirable to transfer and confirm to, and to vest in, each
successor Trustee all the rights, powers, trusts and duties of the retiring
Trustee with respect to the Securities of that or those series to which the
appointment of such successor Trustee relates, (2) if the retiring Trustee is
not retiring with respect to all Securities, shall contain such provisions as
shall be deemed necessary or desirable to confirm that all the rights, powers,
trusts and duties of the retiring Trustee with respect to the Securities of that
or those series as to which the retiring Trustee is not retiring shall continue
to be vested in the retiring Trustee, and (3) shall add to or change any of the
provisions of this Indenture as shall be necessary to provide for or facilitate
the administration of the trusts hereunder by more than one Trustee, it being
understood that nothing herein or in such supplemental indenture shall
constitute such Trustees co-trustees of the same trust and that each such
Trustee shall be trustee of a trust or trusts hereunder separate and apart from
any trust or trusts hereunder administered by any other such Trustee; and upon
the execution and delivery of such supplemental indenture the resignation or
removal of the retiring Trustee shall become effective to the extent provided
therein and each such successor Trustee, without any further act, deed or
conveyance, shall become vested with all the rights, powers, trusts and duties
of the retiring Trustee with respect to the Securities of that or those series
to which the appointment of such successor Trustee relates; but, on request of
the Company or any successor Trustee, such retiring Trustee shall duly assign,
transfer and deliver to such successor Trustee all property and money held by
such retiring Trustee hereunder with respect to the Securities of that or those
series to which the appointment of such successor Trustee relates.

     Upon request of any such successor Trustee, the Company shall execute any
and all instruments for more fully and certainly vesting in and confirming to
such successor Trustee all such rights, powers and trusts referred to in the
first or second preceding paragraph, as the case may be.

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

     SECTION 612.  MERGER, CONVERSION, CONSOLIDATION OR SUCCESSION TO BUSINESS.

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

     SECTION 613.  PREFERENTIAL COLLECTION OF CLAIMS AGAINST COMPANY. 

     If and when the Trustee shall be or become a creditor of the Company (or 
any other obligor upon the Securities), the Trustee shall be subject to the
provisions of the trust 

                                      -38-
<PAGE>
 
indenture act regarding the collection of claims against the company (or any
such other obligor).

     SECTION 614.  APPOINTMENT OF AUTHENTICATING AGENT.

     The Trustee may appoint an Authenticating Agent or Agents with respect to
one or more series of Securities which shall be authorized to act on behalf of
the Trustee to authenticate Securities of such series issued upon original issue
and upon exchange, registration of transfer or partial redemption thereof or
pursuant to Section 306, and Securities so authenticated shall be entitled to
the benefits of this Indenture and shall be valid and obligatory for all
purposes as if authenticated by the Trustee hereunder.  Wherever reference is
made in this Indenture to the authentication and delivery of Securities by the
Trustee or the Trustee's certificate of authentication, such reference shall be
deemed to include authentication and delivery on behalf of the Trustee by an
Authenticating Agent and a certificate of authentication executed on behalf of
the Trustee by an Authenticating Agent.  Each Authenticating Agent shall be
acceptable to the Company and shall at all times be a Person organized and doing
business under the laws of the United States of America, any State thereof or
the District of Columbia, authorized under such laws to act as Authenticating
Agent, having a combined capital and surplus of not less than $50,000,000 and
subject to supervision or examination by Federal or State authority.  If such
Authenticating Agent publishes reports of condition at least annually, pursuant
to law or to the requirements of said supervising or examining authority, then
for the purposes of this Section, the combined capital and surplus of such
Authenticating Agent shall be deemed to be its combined capital and surplus as
set forth in its most recent report of condition so published.  If at any time
an Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, such Authenticating Agent shall resign immediately
in the manner and with the effect specified in this Section.

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

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

                                      -39-
<PAGE>
 
     The Trustee agrees to pay to each Authenticating Agent from time to time
reasonable compensation for its services under this Section, and the Trustee
shall be entitled to be reimbursed for such payments, subject to the provisions
of Section 607.

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

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


                                  [Trustee], as Trustee



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

                                  By:  Authorized Officer


                                 ARTICLE SEVEN

     HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

     SECTION 701.  COMPANY TO FURNISH TRUSTEE NAMES AND ADDRESSES  OF HOLDERS.

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

          (1)  semi-annually, not later than [January 31] and [July 31] in each
     year, a list, in such form as the Trustee may reasonably require, of the
     names and addresses of the Holders of Securities of each series as of the
     preceding [January 15] or [July 15], as the case may be, and

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

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

     SECTION 702.  PRESERVATION OF INFORMATION; COMMUNICATIONS TO HOLDERS.

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

                                      -40-
<PAGE>
 
     The rights of Holders to communicate with other Holders with respect to
their rights under this Indenture or under the Securities, and the corresponding
rights and privileges of the Trustee, shall be as provided by the Trust
Indenture Act.

     Every Holder of Securities, by receiving and holding the same, agrees with
the Company and the Trustee that neither the Company nor the Trustee nor any
agent of either of them shall be held accountable by reason of any disclosure of
information as to names and addresses of Holders made pursuant to the Trust
Indenture Act.

     SECTION 703.  REPORTS BY TRUSTEE.

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

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

     SECTION 704.  REPORTS BY COMPANY. 

     The Company shall file with the Trustee and the Commission, and transmit to
Holders, such information, documents and other reports, and such summaries
thereof, as may be required pursuant to the Trust Indenture Act at the times and
in the manner provided pursuant to such act; provided that any such information,
documents or reports required to be filed with the Commission pursuant to
Section 13 or 15(d) of the Exchange Act shall be filed with the Trustee within
15 days after the same is so required to be filed with the Commission.

                                 ARTICLE EIGHT

             CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

     SECTION 801.  COMPANY MAY CONSOLIDATE, ETC., ONLY ON CERTAIN TERMS.

     The Company shall not consolidate with or merge into any other Person or
convey, transfer or lease its properties and assets substantially as an entirety
to any Person, and the Company shall not permit any Person to consolidate with
or merge into the Company or convey, transfer or lease its properties and assets
substantially as an entirety to the Company, unless:

          (1)  in case the Company shall consolidate with or merge into another
     Person or convey, transfer or lease its properties and assets substantially
     as an entirety to any Person, the Person formed by such consolidation or
     into which the Company is merged or the Person which acquires by conveyance
     or transfer, or which leases, the properties and assets of the Company
     substantially as an entirety shall be a corporation, partnership or trust,
     shall be organized and validly existing under the laws of the United States
     of America, any State thereof or the District of Columbia and shall
     expressly assume, by an indenture supplemental hereto, 

                                      -41-
<PAGE>
 
     executed and delivered to the Trustee, in form satisfactory to the Trustee,
     the due and punctual payment of the principal of and any premium and
     interest on all the Securities and the performance or observance of every
     covenant of this Indenture on the part of the Company to be performed or
     observed;

          (2)  immediately after giving effect to such transaction and treating
     any indebtedness which becomes an obligation of the Company or any
     Subsidiary as a result of such transaction as having been incurred by the
     Company or such Subsidiary at the time of such transaction, no Event of
     Default, and no event which, after notice or lapse of time or both, would
     become an Event of Default, shall have happened and be continuing; and

          (3)  the Company has delivered to the Trustee an Officers' Certificate
     and an Opinion of Counsel, each stating that such consolidation, merger,
     conveyance, transfer or lease and, if a supplemental indenture is required
     in connection with much transaction, such supplemental indenture comply
     with this Article and that all conditions precedent herein provided for
     relating to such transaction have been complied with.

     SECTION 802.  SUCCESSOR SUBSTITUTED. 

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

                                 ARTICLE NINE

                            SUPPLEMENTAL INDENTURES

     SECTION 901.  SUPPLEMENTAL INDENTURES WITHOUT CONSENT OF HOLDERS

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

          (1)  to evidence the succession of another Person to the Company and
     the assumption by any such successor of the covenants of the Company herein
     and in the Securities; or

          (2)  to add to the covenants of the Company for the benefit of the
     Holders of all or any series of Securities (and if such covenants are to be
     for the benefit of less than all series of Securities, stating that such
     covenants are expressly being included solely for the benefit of such
     series) or to surrender any right or power herein conferred upon the
     Company; or

                                      -42-
<PAGE>
 
          (3)  to add any additional Events of Default for the benefit of the
     Holders of all or any series of Securities (and if such additional Events
     of Default are to be for the benefit of less than all series of Securities,
     stating that such additional Events of Default are expressly being included
     solely for the benefit of such series); or

          (4)  to add to or change any of the provisions of this Indenture to
     such extent as shall be necessary to permit or facilitate the issuance of
     Securities in bearer form, registrable or not registrable as to principal,
     and with or without interest coupons, or to permit or facilitate the
     issuance of Securities in uncertificated form; or

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

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

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

          (8)  to make provision with respect to the conversion rights of
     Holders pursuant to the requirements of Article Fourteen hereof, including
     providing for the conversion of the Securities into any security or
     property (other than the Common Stock of the Company); or

          (9)  to cure any ambiguity, to correct or supplement any provision
     herein which may be defective or inconsistent with any other provision
     herein, or to make any other provisions with respect to matters or
     questions arising under this Indenture, provided that such action pursuant
     to this Clause (9) shall not adversely affect the interests of the Holders
     of Securities of any series in any material respect.

     SECTION 902.  SUPPLEMENTAL INDENTURES WITH CONSENT OF HOLDERS

     With the consent of the Holders of not less than a majority in principal
amount of the Outstanding Securities of each series affected by such
supplemental indenture, by Act of said Holders delivered to the Company and the
Trustee, the Company, when authorized by a Board Resolution, and the Trustee may
enter into an indenture or indentures supplemental hereto for the purpose of
adding any provisions to or changing in any manner or eliminating any of the
provisions of this Indenture or of modifying in any manner the rights of the
Holders of Securities of such series under this Indenture; 

                                      -43-
<PAGE>
 
provided, however, that no such supplemental indenture shall, without the
consent of the Holder of each Outstanding Security affected thereby:

          (1)  change the Stated Maturity of the principal of, or any
     installment of principal of or interest on, any Security, or reduce the
     principal amount thereof or the rate of interest thereon or any premium
     payable upon the redemption thereof, or reduce the amount of the principal
     of an Original Issue Discount Security or any other Security which would be
     due and payable upon a declaration of acceleration of the Maturity thereof
     pursuant to Section 502, or adversely affect any right of repayment at the
     option of a Holder of any Security, or reduce the amount of, or postpone
     the date fixed for, the payment of any sinking fund or analogous
     obligation, or change any Place of Payment where, or the coin or currency
     in which, any Security or any premium or interest thereon is payable, or
     impair the right to institute suit for the enforcement of any such payment
     on or after the Stated Maturity thereof (or, in the case of redemption, on
     or after the Redemption Date), or

          (2)  reduce the percentage in principal amount of the Outstanding
     Securities of any series, the consent of whose Holders is required for any
     such supplemental indenture, or the consent of whose Holders is required
     for any waiver (of compliance with certain provisions of this Indenture or
     certain defaults hereunder and their consequences) provided for in this
     Indenture, or

          (3)  modify any of the provisions of this Section, Section 513 or
     Section 1008, except to increase any such percentage or to provide that
     certain other provisions of this Indenture cannot be modified or waived
     without the consent of the Holder of each Outstanding Security affected
     thereby; provided, however, that this clause shall not be deemed to require
     the consent of any Holder with respect to changes in the references to "the
     Trustee" and concomitant changes in this Section and Section 1008, or the
     deletion of this proviso, in accordance with the requirements of Sections
     611 and 901(7), or

          (4)  make any change that adversely affects the right to convert any
     Security of any series as provided in Article Fourteen hereof or pursuant
     to Section 301 (except as permitted by Section 901) or decrease the
     conversion rate or increase the conversion price of any such Security of
     such series, or

          (5)  make any change in Article Fifteen hereof that adversely affects
     the rights of any Holders of Outstanding Securities of such series.

If the Securities of such series are held by a Nuevo Trust or a trustee of such
trust, such supplemental indenture shall not be effective until the holders of a
majority in liquidation preference of Trust Securities of the applicable Trust
shall have consented to such supplemental indenture; provided, that if the
consent of the Holder of each Outstanding Security of such series is required,
such supplemental indenture shall not be effective until each holder of the
Trust Securities of the applicable Nuevo Trust shall have consented to such
supplemental indenture.

     A supplemental indenture which changes or eliminates any covenant or other
provision of this Indenture which has expressly been included solely for the
benefit of one or more particular series of Securities, or which modifies the
rights of the Holders of 

                                      -44-
<PAGE>
 
Securities of such series with respect to such covenant or other provision,
shall be deemed not to affect the rights under this Indenture of the Holders of
Securities of any other series.

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

     SECTION 903.  EXECUTION OF SUPPLEMENTAL INDENTURES.

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

     SECTION 904.  EFFECT OF SUPPLEMENTAL INDENTURES

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

     SECTION 905.  CONFORMITY WITH TRUST INDENTURE ACT

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

     SECTION 906.  REFERENCE IN SECURITIES TO SUPPLEMENTAL INDENTURES.

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

                                  ARTICLE TEN

                                   COVENANTS

     SECTION 1001.  PAYMENT OF PRINCIPAL, PREMIUM AND INTEREST.

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

                                      -45-
<PAGE>
 
     SECTION 1002.  MAINTENANCE OF OFFICE OR AGENC

     The Company will maintain in each Place of Payment for any series of
Securities an office or agency where Securities of that series may be presented
or surrendered for payment, where Securities of that series may be surrendered
for registration of transfer, exchange or conversion and where notices and
demands to or upon the Company in respect of the Securities of that series and
this Indenture may be served.  The Company will give prompt written notice to
the Trustee of the location, and any change in the location, of such office or
agency.  If at any time the Company shall fail to maintain any such required
office or agency or shall fail to furnish the Trustee with the address thereof,
such presentations, surrenders, notices and demands may be made or served at the
Corporate Trust Office of the Trustee, and the Company hereby appoints the
Trustee as its agent to receive all such presentations, surrenders, notices and
demands.

     The Company may also from time to time designate one or more other offices
or agencies where the Securities of one or more series may be presented or
surrendered for any or all such purposes and may from time to time rescind such
designations; provided, however, that no such designation or rescission shall in
any manner relieve the Company of its obligation to maintain an office or agency
in each Place of Payment for Securities of any series for such purposes.  The
Company will give prompt written notice to the Trustee of any such designation
or rescission and of any change in the location of any such other office or
agency.

     SECTION 1003.  MONEY FOR SECURITIES PAYMENTS TO BE HELD IN TRUST.

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

     Whenever the Company shall have one or more Paying Agents for any series of
Securities, it will, prior to each due date of the principal of or any premium
or interest on any Securities of that series, deposit with a Paying Agent a sum
sufficient to pay such amount, such sum to be held as provided by the Trust
Indenture Act, and (unless such Paying Agent is the Trustee) the Company will
promptly notify the Trustee of its action or failure so to act.

     The Company will cause each Paying Agent for any series of Securities other
than the Trustee to execute and deliver to the Trustee an instrument in which
such Paying Agent shall agree with the Trustee, subject to the provisions of
this Section, that such Paying Agent will (1) comply with the provisions of the
Trust Indenture Act applicable to it as a Paying Agent and (2) during the
continuance of any default by the Company (or any other obligor upon the
Securities of that series) in the making of any payment in respect of the
Securities of that series, upon the written request of the Trustee, forthwith
pay to the Trustee all sums held in trust by such Paying Agent for payment in
respect of the Securities of that series.

                                      -46-
<PAGE>
 
     The Company may at any time, for the purpose of obtaining the satisfaction
and discharge of this Indenture or for any other purpose, pay, or by Company
Order direct any Paying Agent to pay, to the Trustee all sums held in trust by
the Company or such Paying Agent, such sums to be held by the Trustee upon the
same trusts as those upon which such sums were held by the Company or such
Paying Agent; and, upon such payment by any Paying Agent to the Trustee, such
Paying Agent shall be released from all further liability with respect to such
money.

     Any money deposited with the Trustee or any Paying Agent, or then held by
the Company, in trust for the payment of the principal of or any premium or
interest on any Security of any series and remaining unclaimed for two years
after such principal, premium or interest has become due and payable shall be
paid to the Company on Company Request, or (if then held by the Company) shall
be discharged from such trust; and the Holder of such Security shall thereafter,
as an unsecured general creditor, look only to the Company for payment thereof,
and all liability of the Trustee or such Paying Agent with respect to such trust
money, and all liability of the Company as trustee thereof, shall thereupon
cease; provided, however, that the Trustee or such Paying Agent, before being
required to make any such repayment, may at the expense of the Company cause to
be published once, in a newspaper published in the English language, customarily
published on each Business Day and of general circulation in the Borough of
Manhattan, The City of New York, notice that such money remains unclaimed and
that, after a date specified therein, which shall not be less than 30 days from
the date of such publication, any unclaimed balance of such money then remaining
will be repaid to the Company.  The Paying Agent shall be entitled to the rights
and protections extended to the Trustee hereunder.

     SECTION 1004.  STATEMENT BY OFFICERS AS TO DEFAULT.

     The Company will deliver to the Trustee, within 120 days after the end of
each fiscal year of the Company ending after the date hereof, an Officers'
Certificate, stating whether or not to the best knowledge of the signers thereof
the Company is in default in the performance and observance of any of the terms,
provisions and conditions of this Indenture (without regard to any period of
grace or requirement of notice provided hereunder) and, if the Company shall be
in default, specifying all such defaults and the nature and status thereof of
which they may have knowledge.

     SECTION 1005.  EXISTENCE.

     Subject to Article Eight, the Company will do or cause to be done all
things necessary to preserve and keep in full force and effect its existence,
rights (charter and statutory) and franchises; provided, however, that the
Company shall not be required to preserve any such right or franchise if the
Board of Directors shall determine that the preservation thereof is no longer
desirable in the conduct of the business of the Company and that the loss
thereof is not disadvantageous in any material respect to the Holders.

     SECTION 1006.  MAINTENANCE OF PROPERTIES. 

    The Company will cause all properties used or useful in the conduct of its
business or the business of any Subsidiary to be maintained and kept in good
condition, repair and working order and supplied with all necessary equipment
and will cause to be made all necessary repairs, renewals, replacements,
betterments and improvements thereof, all as in 

                                      -47-
<PAGE>
 
the judgment of the Company may be necessary so that the business carried on in
connection therewith may be properly and advantageously conducted at all times;
provided, however, that nothing in this Section shall prevent the Company from
discontinuing the operation or maintenance of any of such properties if such
discontinuance is, in the judgment of the Company, desirable in the conduct of
its business or the business of any Subsidiary and not disadvantageous in any
material respect to the Holders.

     SECTION 1007.  PAYMENT OF TAXES AND OTHER CLAIMS.

     The Company will pay or discharge or cause to be paid or discharged, before
the same shall become delinquent, (1) all taxes, assessments and governmental
charges levied or imposed upon the Company or any Subsidiary or upon the income,
profits or property of the Company or any Subsidiary, and (2) all lawful claims
for labor, materials and supplies which, if unpaid, might by law become a lien
upon the property of the Company or any Subsidiary; provided, however, that the
Company shall not be required to pay or discharge or cause to be paid or
discharged any such tax, assessment, charge or claim whose amount, applicability
or validity is being contested in good faith by appropriate proceedings.

     SECTION 1008.  WAIVER OF CERTAIN COVENANTS.

     Except as otherwise specified as contemplated by Section 301 for Securities
of such series, the Company may, with respect to the Securities of any series,
omit in any particular instance to comply with any term, provision or condition
set forth in any covenant provided pursuant to Section 301(20), 901(2) or 901(6)
for the benefit of the Holders of such series or in any of Sections 1006, 1007
and 1009, if before the time for such compliance the Holders of at least a
majority in principal amount of the Outstanding Securities of such series shall,
by Act of such Holders, either waive such compliance in such instance or
generally waive compliance with such term, provision or condition, but no such
waiver shall extend to or affect such term, provision or condition except to the
extent so expressly waived, and, until such waiver shall become effective, the
obligations of the Company and the duties of the Trustee in respect of any such
term, provision or condition shall remain in full force and effect.

     SECTION 1009.  COVENANTS AS TO NUEVO TRUST.

     In the event Securities are issued to the Nuevo Trust or a trustee of such
trust in connection with the issuance of Trust Securities by the Nuevo Trust,
for so long as such Trust Securities remain outstanding, the Company will (1)
maintain 100% direct or indirect ownership of the Common Securities of the Nuevo
Trust; provided, however, that any permitted successor of the Company under the
Indenture may succeed to the Company's ownership of the Common Securities, (2)
use its reasonable efforts to cause the Nuevo Trust (A) to remain a statutory
business trust, except in connection with a distribution of Securities of such
series to the holders of Trust Securities in liquidation of the Nuevo Trust, the
redemption of all of the Trust Securities of the Nuevo Trust, or certain
mergers, consolidations or amalgamations, each as permitted by the Declaration
of the Nuevo Trust, and (B) to continue to be classified as a grantor trust for
United States federal income tax purposes and (3) to use its reasonable efforts
to cause each holder of Trust Securities to be treated as owning an undivided
beneficial interest in the Securities of such series.

                                      -48-
<PAGE>
 
                                ARTICLE ELEVEN

                           REDEMPTION OF SECURITIES

     SECTION 1101.  APPLICABILITY OF ARTICLE.

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

     SECTION 1102.  ELECTION TO REDEEM; NOTICE TO TRUSTEE

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

     SECTION 1103.  SELECTION BY TRUSTEE OF SECURITIES TO BE REDEEMED.

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

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

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

                                      -49-
<PAGE>
 
     If Securities of any series selected for partial redemption are converted
in part before termination of the conversion right with respect to the portion
of the Securities of such series so selected, the converted portion of the
Securities of such series shall be deemed (so far as may be) to be the portion
selected for redemption.  Securities (or portions thereof) which have been
converted during a selection of Securities of such series to be redeemed shall
be treated by the Trustee as Outstanding for the purpose of such selection.  In
any case where more than one Security of such series is registered in the same
name, the Trustee in its discretion may treat the aggregate principal amount so
registered as if it were represented by one Security of such series.

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

     SECTION 1104.  NOTICE OF REDEMPTION.

     Notice of redemption shall be given by first-class mail, postage prepaid,
mailed not less than 30 nor more than 60 days prior to the Redemption Date, to
each Holder of Securities to be redeemed, at his address appearing in the
Security Register.

     All notices of redemption shall state:

          (1)  the Redemption Date,

          (2)  the Redemption Price,

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

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

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

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

          (7)  if applicable, the conversion rate or price, the date on which
     the right to convert the Securities of such series to be redeemed will
     terminate and the place or places where such Securities may be surrendered
     for conversion.

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

                                      -50-
<PAGE>
 
     SECTION 1105.  DEPOSIT OF REDEMPTION PRICE.

     Prior to any Redemption Date, the Company shall deposit with the Trustee or
with a Paying Agent (or, if the Company is acting as its own Paying Agent,
segregate and hold in trust as provided in Section 1003) an amount of money
sufficient to pay the Redemption Price of, and (except if the Redemption Date
shall be an interest Payment Date) accrued interest on, all the Securities which
are to be redeemed on that date.

     If any Security called for redemption is converted into Common Stock of the
Company, any money deposited with the Trustee or with any Paying Agent or so
segregated and held in trust for the redemption of such Security shall (subject
to any right of the Holder of such Security or any Predecessor Security to
receive interest as provided in the last paragraph of Section 307) be paid to
the Company upon Company Request or, if then held by the Company, shall be
discharged from such trust.

     SECTION 1106.  SECURITIES PAYABLE ON REDEMPTION DATE.

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

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

     SECTION 1107.  SECURITIES REDEEMED IN PART

     Any Security which is to be redeemed only in part shall be surrendered at a
Place of Payment therefor (with, if the Company or the Trustee so requires, due
endorsement by, or a written instrument of transfer in form satisfactory to the
Company and the Trustee duly executed by, the Holder thereof or his attorney
duly authorized in writing), and the Company shall execute, and the Trustee
shall authenticate and deliver to the Holder of such Security without service
charge, a new Security or Securities of the same series and of like tenor, of
any authorized denomination as requested by such Holder, in aggregate principal
amount equal to and in exchange for the unredeemed portion of the principal of
the Security so surrendered.

                                      -51-
<PAGE>
 
                                ARTICLE TWELVE

                                 SINKING FUNDS

     SECTION 1201.  APPLICABILITY OF ARTICLE.

     The provisions of this Article shall be applicable to any sinking fund for
the retirement of Securities of any series except as otherwise specified as
contemplated by Section 301 for such Securities.

     The minimum amount of any sinking fund payment provided for by the terms of
any Securities is herein referred to as a "mandatory sinking fund payment", and
any payment in excess of such minimum amount provided for by the terms of such
Securities is herein referred to as an "optional sinking fund payment".  If
provided for by the terms of any Securities, the cash amount of any sinking fund
payment may be subject to reduction as provided in Section 1202.  Each sinking
fund payment shall be applied to the redemption of Securities as provided for by
the terms of such Securities.

     SECTION 1202.  SATISFACTION OF SINKING FUND PAYMENTS WITH SECURITIES.

     The Company (1) may deliver Outstanding Securities of a series (other than
any previously called for redemption) and (2) may apply as a credit Securities
of a series which have been redeemed either at the election of the Company
pursuant to the terms of such Securities or through the application of permitted
optional sinking fund payments pursuant to the terms of such Securities, in each
case in satisfaction of all or any part of any sinking fund payment with respect
to any Securities of such series required to be made pursuant to the terms of
such Securities as and to the extent provided for by the terms of such
Securities; provided that the Securities to be so credited have not been
previously so credited.  The Securities to be so credited shall be received and
credited for such purpose by the Trustee at the Redemption Price, as specified
in the Securities so to be redeemed, for redemption through operation of the
sinking fund and the amount of such sinking fund payment shall be reduced
accordingly.

     SECTION 1203.  REDEMPTION OF SECURITIES FOR SINKING FUND.

     Not less than 45 days prior to each sinking fund payment date for any
Securities, the Company will deliver to the Trustee an Officers' Certificate
specifying the amount of the next ensuing sinking fund payment for such
Securities pursuant to the terms of such Securities, the portion thereof, if
any, which is to be satisfied by payment of cash and the portion thereof, if
any, which is to be satisfied by delivering and crediting Securities pursuant to
Section 1202 and will also deliver to the Trustee any Securities to be so
delivered.  Not less than 30 days prior to each such sinking fund payment date,
the Trustee shall select the Securities to be redeemed upon such sinking fund
payment date in the manner specified in Section 1103 and cause notice of the
redemption thereof to be given in the name of and at the expense of the Company
in the manner provided in Section 1104.  Such notice having been duly given, the
redemption of such Securities shall be made upon the terms and in the manner
stated in Sections 1106 and 1107.

                                      -52-
<PAGE>
 
                               ARTICLE THIRTEEN

                      DEFEASANCE AND COVENANT DEFEASANCE

     SECTION 1301.  COMPANY'S OPTION TO EFFECT DEFEASANCE OR COVENANT
DEFEASANCE.

     The Company may elect, at its option at any time, to have Section 1302 or
Section 1303 applied to any Securities or any series of Securities, as the case
may be, designated pursuant to Section 301 as being defeasible pursuant to such
Section 1302 or 1303, in accordance with any applicable requirements provided
pursuant to Section 301 and upon compliance with the conditions set forth below
in this Article.  Any such election shall be evidenced by a Board Resolution or
in another manner specified as contemplated by Section 301 for such Securities.

     SECTION 1302.  DEFEASANCE AND DISCHARGE

     Upon the Company's exercise of its option (if any) to have this Section
applied to any Securities or any series of Securities, as the case may be, the
Company shall be deemed to have been discharged from its obligations with
respect to such Securities as provided in this Section on and after the date the
conditions set forth in Section 1304 are satisfied (hereinafter called
"Defeasance").  For this purpose, such Defeasance means that the Company shall
be deemed to have paid and discharged the entire indebtedness represented by
such Securities and to have satisfied all its other obligations under such
Securities and this Indenture insofar as such Securities are concerned (and the
Trustee, at the expense of the Company, shall execute proper instruments
acknowledging the same), subject to the following which shall survive until
otherwise terminated or discharged hereunder: (1) the rights of Holders of such
Securities to receive, solely from the trust fund described in Section 1304 and
as more fully set forth in such Section, payments in respect of the principal of
and any premium and interest on such Securities when payments are due, (2) the
Company's obligations with respect to such Securities under Sections 304, 305,
306, 1002 and 1003, (3) the rights, powers, trusts, duties and immunities of the
Trustee hereunder and (4) this Article.  Subject to compliance with this
Article, the Company may exercise its option (if any) to have this Section
applied to any Securities notwithstanding the prior exercise of its option (if
any) to have Section 1303 applied to such Securities.

     SECTION 1303.  COVENANT DEFEASANCE.

Upon the Company's exercise of its option (if any) to have this Section applied
to any Securities or any series of Securities, as the case may be, (1) the
Company shall be released from its obligations under Sections 1006, 1007 and
1009, and any covenants provided pursuant to Section 301(20), 901(2) or 901(6)
for the benefit of the Holders of such Securities and (2) the occurrence of any
event specified in Sections 501(5) (with respect to any of Sections 1006, 1007
and 1009, and any such covenants provided pursuant to Section 301(20), 901(2) or
901(6)) and 501(9) shall be deemed not to be or result in an Event of Default,
in each case with respect to such Securities as provided in this Section on and
after the date the conditions set forth in Section 1304 are satisfied
(hereinafter called "Covenant Defeasance").  For this purpose, such Covenant
Defeasance means that, with respect to such Securities, the Company may omit to
comply with and shall have no liability in respect of any term, condition or
limitation set forth in any such specified Section (to the extent so specified
in the case of Section 501(5) and 501(8)), 

                                      -53-
<PAGE>
 
whether directly or indirectly by reason of any reference elsewhere herein to
any such Section or by reason of any reference in any such Section to any other
provision herein or in any other document, but the remainder of this Indenture
and such Securities shall be unaffected thereby.

     SECTION 1304.  CONDITIONS TO DEFEASANCE OR COVENANT DEFEASANCE.

     The following shall be the conditions to the application of Section 1302 or
Section 1303 to any Securities or any series of Securities, as the case may be:

          (1)  The Company shall irrevocably have deposited or caused to be
     deposited with the Trustee (or another trustee which satisfies the
     requirements contemplated by Section 609 and agrees to comply with the
     provisions of this Article applicable to it) as trust funds in trust for
     the purpose of making the following payments, specifically pledged as
     security for, and dedicated solely to, the benefits of the Holders of such
     Securities, (A) money in an amount, or (B) U.S. Government Obligations
     which through the scheduled payment of principal and interest in respect
     thereof in accordance with their terms will provide, not later than one day
     before the due date of any payment, money in an amount, or (C) a
     combination thereof, in each case sufficient, in the opinion of a
     nationally recognized firm of independent public accountants expressed in a
     written certification thereof delivered to the Trustee, to pay and
     discharge, and which shall be applied by the Trustee (or any such other
     qualifying trustee) to pay and discharge, the principal of and any premium
     and interest on such Securities on the respective Stated Maturities, in
     accordance with the terms of this Indenture and such Securities.  As used
     herein, "U.S. Government Obligation" means (x) any security which is (i) a
     direct obligation of the United States of America for the payment of which
     the full faith and credit of the United States of America is pledged or
     (ii) an obligation of a Person controlled or supervised by and acting as an
     agency or instrumentality of the United States of America the payment of
     which is unconditionally guaranteed as a full faith and credit obligation
     by the United States of America, which, in either case (i) or (ii), is not
     callable or redeemable at the option of the issuer thereof, and (y) any
     depository receipt issued by a bank (as defined in Section 3(a)(2) of the
     Securities Act) as custodian with respect to any U.S. Government Obligation
     which is specified in Clause (x) above and held by such bank for the
     account of the holder of such depository receipt, or with respect to any
     specific payment of principal of or interest on any U.S. Government
     Obligation which is so specified and held, provided that (except as
     required by law) such custodian is not authorized to make any deduction
     from the amount payable to the holder of such depository receipt from any
     amount received by the custodian in respect of the U.S. Government
     Obligation or the specific payment of interest evidenced by such depository
     receipt.

          (2)  In the event of an election to have Section 1302 apply to any
     Securities or any series of Securities, as the case may be, the Company
     shall have delivered to the Trustee an Opinion of Counsel stating that (A)
     the Company has received from, or there has been published by, the Internal
     Revenue Service a ruling or (B) since the date of this instrument, there
     has been a change in the applicable Federal income tax law, in either case
     (A) or (B) to the effect that, and based thereon such opinion shall confirm
     that, the Holders of such Securities will not recognize gain or loss for
     Federal income tax purposes as a result of the 

                                      -54-
<PAGE>
 
     deposit, Defeasance and discharge to be effected with respect to such
     Securities and will be subject to Federal income tax on the same amounts,
     in the same manner and at the same times as would be the case if such
     deposit, Defeasance and discharge were not to occur.

          (3)  In the event of an election to have Section 1303 apply to any
     Securities or any series of Securities, as the case may be, the Company
     shall have delivered to the Trustee an Opinion of Counsel to the effect
     that the Holders of such Securities will not recognize gain or loss for
     Federal income tax purposes as a result of the deposit and Covenant
     Defeasance to be effected with respect to such Securities and will be
     subject to Federal income tax on the same amounts, in the same manner and
     at the same times as would be the case if such deposit and Covenant
     Defeasance were not to occur.

          (4)  The Company shall have delivered to the Trustee an Officer's
     Certificate to the effect that neither such Securities nor any other
     Securities of the same series, if then listed on any securities exchange,
     will be delisted as a result of such deposit.

          (5)  No event which is, or after notice or lapse of time or both would
     become, an Event of Default with respect to such Securities or any other
     Securities shall have occurred and be continuing at the time of such
     deposit or, with regard to any such event specified in Sections 501(6) and
     (7), at any time on or prior to the 90th day after the date of such deposit
     (it being understood that this condition shall not be deemed satisfied
     until after such 90th day).

          (6)  Such Defeasance or Covenant Defeasance shall not cause the
     Trustee to have a conflicting interest within the meaning of the Trust
     Indenture Act (assuming all Securities are in default within the meaning of
     such Act).

          (7)  Such Defeasance or Covenant Defeasance shall not result in a
     breach or violation of, or constitute a default under, any other agreement
     or instrument to which the Company is a party or by which it is bound.

          (8)  Such Defeasance or Covenant Defeasance shall not result in the
     trust arising from such deposit constituting an investment company within
     the meaning of the Investment Company Act unless such trust shall be
     registered under such Act or exempt from registration thereunder.

          (9)  The Company shall have delivered to the Trustee an Officer's
     Certificate and an Opinion of Counsel, each stating that all conditions
     precedent with respect to such Defeasance or Covenant Defeasance have been
     complied with.

          (10) No default in the payment of the principal of and any premium and
     interest on any Senior Indebtedness beyond any applicable grace period
     shall have occurred and be continuing.

          (11) No other default with respect to any Senior Indebtedness shall
     have occurred and be continuing and shall have resulted in the acceleration
     of such Senior Indebtedness.

                                      -55-
<PAGE>
 
     SECTION 1305.  DEPOSITED MONEY AND U.S. GOVERNMENT OBLIGATIONS TO BE HELD
IN TRUST; MISCELLANEOUS PROVISIONS.

     Subject to the provisions of the last paragraph of Section 1003, all money
and U.S. Government Obligations (including the proceeds thereof) deposited with
the Trustee or other qualifying trustee (solely for purposes of this Section and
Section 1306, the Trustee and any such other trustee are referred to
collectively as the "Trustee") pursuant to Section 1304 in respect of any
Securities shall be held in trust and applied by the Trustee, in accordance with
the provisions of such Securities and this Indenture, to the payment, either
directly or through any such Paying Agent (including the Company acting as its
own Paying Agent) as the Trustee may determine, to the Holders of such
Securities, of all sums due and to become due thereon in respect of principal
and any premium and interest, but money so held in trust need not be segregated
from other funds except to the extent required by law.

     The Company shall pay and indemnify the Trustee against any tax, fee or
other charge imposed on or assessed against the U.S. Government Obligations
deposited pursuant to Section 1304 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 Outstanding Securities.

     Anything in this Article to the contrary notwithstanding, the Trustee shall
deliver or pay to the Company from time to time upon Company Request any money
or U.S. Government Obligations held by it as provided in Section 1304 with
respect to any Securities which, in the opinion of a nationally recognized firm
of independent public accountants expressed in a written certification thereof
delivered to the Trustee, are in excess of the amount thereof which would then
be required to be deposited to effect the Defeasance or Covenant Defeasance, as
the case may be, with respect to such Securities.

     SECTION 1306.  REINSTATEMENT.

     If the Trustee or the Paying Agent is unable to apply any money in
accordance with this Article with respect to any Securities by reason of any
order or judgment of any court or governmental authority enjoining, restraining
or otherwise prohibiting such application, then the obligations under this
Indenture and such Securities from which the Company has been discharged or
released pursuant to Section 1302 or 1303 shall be revived and reinstated as
though no deposit had occurred pursuant to this Article with respect to such
Securities, until such time as the Trustee or Paying Agent is permitted to apply
all money held in trust pursuant to Section 1305 with respect to such Securities
in accordance with this Article; provided, however, that if the Company makes
any payment of principal of or any premium or interest on any such Security
following such reinstatement of its obligations, the Company shall be subrogated
to the rights (if any) of the Holders of such Securities to receive such payment
from the money so held in trust.

                                      -56-
<PAGE>
 
                                ARTICLE FOURTEEN

                           CONVERSION OF SECURITIES

     SECTION 1401.  APPLICABILITY OF ARTICLE.

     The provisions of this Article shall be applicable to the Securities of any
series which are convertible into shares of Common Stock of the Company, and the
issuance of such shares of Common Stock upon the conversion of Securities of
such series, except as otherwise specified as contemplated by Section 301 for
the Securities of such series.  The terms and provisions applicable to the
conversion of Securities of any series into securities of the Company (other
than Common Stock) shall, if applicable, be set forth in an Officers'
Certificate or established in one or more indentures supplemental hereto, prior
to the issuance of Securities of such series in accordance with Section 301.

     SECTION 1402.  EXERCISE OF CONVERSION PRIVILEGE

     In order to exercise a conversion privilege, the Holder of a Security of
any series with such a privilege shall surrender such Security to the Company at
the office or agency maintained for that purpose pursuant to Section 1002,
accompanied by written notice to the Company that the Holder elects to convert
such Security or a specified portion thereof.  Such notice shall also state, if
different from the name and address of such Holder, the name or names (with
address) in which the certificate or certificates for shares of Common Stock
which shall be issuable on such conversion shall be issued.  Securities of such
series surrendered for conversion shall (if so required by the Company or the
Trustee) be duly endorsed by or accompanied by instruments of transfer in forms
satisfactory to the Company and the Trustee duly executed by the Holder or its
attorney duly authorized in writing; and, if expressly specified, as
contemplated by Section 301, to be applicable to any series of Securities,
Securities of such series so surrendered for conversion during the period from
the close of business on any Regular Record Date to the opening of business on
the next succeeding Interest Payment Date (excluding Securities or portions
thereof called for redemption during such period) shall also be accompanied by
payment in funds acceptable to the Company of an amount equal to the interest
payable on such Interest Payment Date on the principal amount of such Security
then being converted, and such interest shall be payable to such Holder
notwithstanding the conversion of such Security, subject to the provisions of
Section 307 relating to the payment of Defaulted Interest by the Company.  As
promptly as practicable after the receipt of such notice and of any payment
required pursuant to a Board Resolution and, subject to Section 301, set forth,
or determined in the manner provided, in an Officers' Certificate, or
established in one or more indentures supplemental hereto setting forth the
terms of the Securities and the surrender of such Securities in accordance with
such reasonable regulations as the Company may prescribe, the Company shall
issue and shall deliver, at the office or agency at which such Security is
surrendered, to such Holder or on its written order, a certificate or
certificates for the number of full shares of Common Stock issuable upon the
conversion of such Security (or specified portion thereof), in accordance with
the provisions of such Board Resolution, Officers' Certificate or supplemental
indenture, and cash as provided therein in respect of any fractional share of
such Common Stock otherwise issuable upon such conversion.  Such conversion
shall be deemed to have been effected immediately prior to the close of business
on the date on which such notice and such payment, if required, shall have been
received in proper order for conversion by the Company and such Security shall
have been surrendered as aforesaid (unless such Holder 

                                      -57-
<PAGE>
 
shall have so surrendered such Security and shall have instructed the Company to
effect the conversion on a particular date following such surrender and such
Holder shall be entitled to convert such Security on such date, in which case
such conversion shall be deemed to be effected immediately prior to the close of
business on such date) and at such time the rights of the Holder of such
Security as such Security Holder shall cease and the person or persons in whose
name or names any certificate or certificates for shares of Common Stock of the
Company shall be issuable upon such conversion shall be deemed to have become
the holder or holders of record of the shares represented thereby. Except as set
forth above and subject to the final paragraph of Section 3.7, no payment or
adjustment shall be made upon any conversion on account of any interest accrued
on the Securities of such series surrendered for conversion or on account of any
dividends on the Common Stock of the Company issued upon such conversion.

     In the case of any Security of any series which is converted in part only,
upon such conversion the Company shall execute and the Trustee shall
authenticate and make available for delivery to or on the order of the Holder
thereof, at the expense of the Company, a new Security or Securities of such
series, of authorized denominations, in aggregate principal amount equal to the
unconverted portion of such Security.

     SECTION 1403.  NO FRACTIONAL SHARES. 

     No fractional share of Common Stock of the Company shall be issued upon
conversions of securities of any series. If more than one security of such
series shall be surrendered for conversion at one time by the same Holder, the
number of full shares which shall be issuable upon conversion shall be computed
on the basis of the aggregate principal amount of the securities of such series
(or specified portions thereof to the extent permitted hereby) so surrendered.
If, except for the provisions of this Section 1403, any Holder of a Security or
Securities of such series would be entitled to a fractional share of Common
Stock of the Company upon the conversion of such Security or Securities, or
specified portions thereof, the Company shall pay to such Holder an amount in
cash equal to the current market value of such fractional share computed, (1) if
such Common Stock is listed or admitted to unlisted trading privileges on a
National securities exchange, on the basis of the last reported sale price
regular way on such exchange on the last trading day prior to the date of
conversion upon which such a sale shall have been effected, or (2) if such
Common Stock is not at the time so listed or admitted to unlisted trading
privileges on a national securities exchange, on the basis of the average of the
bid and asked prices of such Common Stock in the over-the-counter market, on the
last trading day prior to the date of conversion, as reported by the National
Quotation Bureau, incorporated or similar organization if the National Quotation
Bureau, Incorporated is no longer reporting such information, or if not so
available, the fair market price as determined by the Board of Directors. For
purposes of this Section, "trading day" shall mean each Monday, Tuesday,
Wednesday, Thursday and Friday other than any day on which the Common Stock is
not traded on the New York Stock Exchange, or if the Common Stock is not traded
on the New York Stock Exchange, on the principal exchange or market on which the
Common Stock is traded or quoted.

     SECTION 1404.  ADJUSTMENT OF CONVERSION PRICE

     The conversion price of Securities of any series that is convertible into
Common Stock of the Company shall be adjusted for any stock dividends, stock
splits, reclassification, combinations or similar transactions in accordance
with the terms of the supple-

                                      -58-
<PAGE>
 
mental indenture or Board Resolutions setting forth the terms of the Securities
of such series.

     Whenever the conversion price is adjusted, the Company shall compute the
adjusted conversion price in accordance with terms of the applicable Board
Resolution or supplemental indenture and shall prepare an Officers' Certificate
setting forth the adjusted conversion price and showing in reasonable detail the
facts upon which such adjustment is based, and such certificate shall forthwith
be filed at each office or agency maintained for the purpose of conversion of
Securities of such series pursuant to Section 1002 and, if different, with the
Trustee.  The Company shall forthwith cause a notice setting forth the adjusted
conversion price to be mailed, first class postage prepaid, to each Holder of
Securities of such series at its address appearing on the Security Register and
to any conversion agent other than the Trustee.

     SECTION 1405.  NOTICE OF CERTAIN CORPORATE ACTIONS

     In case:

          (1)  the Company shall declare a dividend (or any other distribution)
     on its Common Stock payable otherwise than in cash out of its retained
     earnings (other than a dividend for which approval of any shareholders of
     the Company is required); or

          (2)  the Company shall authorize the granting to the holders of its
     Common Stock of rights, options or warrants to subscribe for or purchase
     any shares of capital stock of any class or of any other rights (other than
     any such grant for which approval of any shareholders of the Company is
     required); or

          (3)  of any reclassification of the Common Stock of the Company (other
     than a subdivision or combination of its outstanding shares of Common
     Stock) or of any consolidation, merger or share exchange to which the
     Company is a party and for which approval of any shareholders of the
     Company is required, or of the sale of all or substantially all of the
     assets of the Company; or

          (4)  of the voluntary or involuntary dissolution, liquidation or
     winding up of the Company;

then the Company shall cause to be filed with the Trustee, and shall cause to be
mailed to all Holders at their last addresses as they shall appear in the
Security Register, at least 20 days (or 10 days in any case specified in clause
(1) or (2) above) prior to the applicable record date hereinafter specified, a
notice stating (A) the date on which a record is to be taken for the purpose of
such dividend, distribution, rights, options or warrants, or, if a record is not
to be taken, the date as of which the holders of Common Stock of record to be
entitled to such dividend, distribution, rights, options or warrants are to be
determined, or (B) the date on which such reclassification, consolidation,
merger, share exchange, sale, dissolution, liquidation or winding up is expected
to become effective, and the date as of which it is expected that holders of
Common Stock of record shall be entitled to exchange their shares of Common
Stock for securities, cash or other property deliverable upon such
reclassification, consolidation, merger, share exchange, sale, dissolution,
liquidation or winding up.  If at any time the Trustee shall not be the
conversion agent, a copy of such notice shall also forthwith be filed by the
Company with the Trustee.

                                      -59-
<PAGE>
 
     SECTION 1406.  RESERVATION OF SHARES OF COMMON STOCK.

     The Company shall at all times reserve and keep available, free from
preemptive rights, out of its authorized but unissued Common Stock or treasury
shares, for the purpose of effecting the conversion of Securities, the full
number of shares of Common Stock of the Company then issuable upon the
conversion of all outstanding Securities of any series that has conversion
rights.

     SECTION 1407.  PAYMENT OF CERTAIN TAXES UPON CONVERSION.

     The Company will pay any and all taxes that may be payable in respect of
the issue or delivery of shares of its Common Stock on conversion of Securities
pursuant hereto.  The Company shall not, however, be required to pay any tax
which may be payable in respect of any transfer involved in the issue and
delivery of shares of its Common Stock in a name other than that of the Holder
of the Security or Securities to be converted, and no such issue or delivery
shall be made unless and until the person requesting such issue has paid to the
Company the amount of any such tax, or has established, to the satisfaction of
the Company, that such tax has been paid.

     SECTION 1408.  NONASSESSABILITY. 

     The Company covenants that all shares of Common Stock which may be issued
upon conversion of securities will upon issue in accordance with the terms
hereof be duly and validly issued and fully paid and nonassessable.

     SECTION 1409.  EFFECT OF CONSOLIDATION OR MERGER ON CONVERSION PRIVILEGE

Unless otherwise provided as contemplated by Section 301 with respect to
Securities of any series, in case of any consolidation of the Company with, or
merger of the Company into or with any other Person, or in case of any sale of
all or substantially all of the assets of the Company, the Company or the Person
formed by such consolidation or the Person into which the Company shall have
been merged or the Person which shall have acquired such assets, as the case may
be, shall execute and deliver to the Trustee a supplemental indenture providing
that the Holder of each Security then outstanding of any series that is
convertible into Common Stock shall have the right, which right shall be the
exclusive conversion right thereafter available to said Holder (until the
expiration of the conversion right of such Security), to convert such Security
into the kind and amount of shares of stock or other securities or property
(including cash) receivable upon such consolidation, merger or sale by a holder
of the number of shares of Common Stock into which such Security might have been
converted immediately prior to such consolidation, merger or sale, subject to
compliance with the other provisions of this Indenture, such Security and such
supplemental indenture.  Such supplemental indenture shall provide for
adjustments which shall be as nearly equivalent as may be practicable to the
adjustments provided for in such Security.  The above provisions of this Section
shall similarly apply to successive consolidations, mergers or sales.  Unless
otherwise provided as contemplated by Section 301 with respect to Securities of
any series, it is expressly agreed and understood that anything in this
Indenture to the contrary notwithstanding, if, pursuant to such merger,
consolidation or sale, holders of outstanding shares of Common Stock do not
receive shares of common stock of the surviving corporation but receive other
securities, cash or other property or any combination thereof, Holders of
Securities shall not have the right to 

                                      -60-
<PAGE>
 
thereafter convert their Securities into common stock of the surviving
corporation or the corporation which shall have acquired such assets, but
rather, shall have the right upon such conversion to receive the other
securities, cash or other property receivable by a holder of the number of
shares of Common Stock into which the Securities held by such Holder might have
been converted immediately prior to such consolidation, merger or sale, all as
more fully provided in the first sentence of this Section 1409. Anything in this
Section 1409 to the contrary notwithstanding, the provisions of this Section
1409 shall not apply to a merger or consolidation of another corporation with or
into the Company pursuant to which both of the following conditions are
applicable: (1) the Company is the surviving corporation and (2) the outstanding
shares of Common Stock are not changed or converted into any other securities or
property (including cash) or changed in number or character or reclassified
pursuant to the terms of such merger or consolidation.

     As evidence of the kind and amount of shares of stock or other securities
or property (including cash) into which Securities may properly be convertible
after any such consolidation, merger or sale, or as to the appropriate
adjustments of the conversion prices applicable with respect thereto, the
Trustee shall be furnished with and may accept the certificate or opinion of an
independent certified public accountant with respect thereto; and, in the
absence of bad faith on the part of the Trustee, the Trustee may conclusively
rely thereon, and shall not be responsible or accountable to any Holder of
Securities for any provision in conformity therewith or approved by such
independent certified public accountant which may be contained in said
supplemental indenture.

     SECTION 1410.  DUTIES OF TRUSTEE REGARDING CONVERSION.

     Neither the Trustee nor any conversion agent shall at any time be under any
duty or responsibility to any Holder of Securities of any series that is
convertible into Common Stock to determine whether any facts exist which may
require any adjustment of the conversion price, or with respect to the nature or
extent of any such adjustment when made, or with respect to the method employed,
whether herein or in any supplemental indenture (or whether a supplemental
indenture need be entered into), any resolutions of the Board of Directors or
written instrument executed by one or more officers of the Company provided to
be employed in making the same.  Neither the Trustee nor any conversion agent
shall be accountable with respect to the validity or value (or the kind or
amount) of any shares of Common Stock, or of any securities or property, which
may at any time be issued or delivered upon the conversion of any Securities and
neither the Trustee nor any conversion agent makes any representation with
respect thereto.  Neither the Trustee nor any conversion agent shall be
responsible for any failure of the Company to issue, transfer or deliver any
shares of Common Stock or stock certificates or other securities or property
upon the surrender of any Security for the purpose of conversion or to comply
with any of the covenants of the Company contained in this Article Fourteen or
in the applicable supplemental indenture, resolutions of the Board of Directors
or written instrument executed by one or more duly authorized officers of the
Company.  All Securities delivered for conversion shall be delivered to the
Trustee to be canceled by or at the direction of the Trustee, which shall
dispose of the same as provided in Section 309.

     SECTION 1411.  REPAYMENT OF CERTAIN FUNDS UPON CONVERSION.

     Any funds which at any time shall have been deposited by the Company or on
its behalf with the Trustee or any other paying agent for the purpose of paying
the principal of, and premium, if any, and interest, if any, on any of the
Securities (including funds 

                                      -61-
<PAGE>
 
deposited for the sinking fund referred to in Article Three hereof) and which
shall not be required for such purposes because of the conversion of such
Securities as provided in this Article Fourteen shall after such conversion be
repaid to the Company by the Trustee upon the Company's written request.

                                ARTICLE FIFTEEN

                          SUBORDINATION OF SECURITIES

     SECTION 1501.  SECURITIES SUBORDINATE TO SENIOR INDEBTEDNESS.

     The Company covenants and agrees, and each Holder, by the Holder's
acceptance thereof, likewise covenants and agrees, that, to the extent and in
the manner hereinafter set forth in this Article, the indebtedness represented
by the Security and the payment of the principal of and premium and interest on
each and all of the Securities are hereby expressly made subordinate and junior
in right of payment to the prior payment in full of all Senior Indebtedness of
the Company, whether outstanding at the date of this Indenture or thereafter
incurred.  No provision of this Article shall prevent the occurrence of any
default or Event of Default hereunder.

     SECTION 1502.  PAYMENT OVER OF PROCEEDS UPON DISSOLUTION, ETC.

     Upon any payment by the Company or distribution of assets of the Company of
any kind or character, whether in cash, property or securities, to creditors
upon any dissolution or winding-up or liquidation or reorganization of the
Company, whether voluntary or involuntary or in bankruptcy, insolvency,
receivership or other proceedings, all amounts due upon all Senior Indebtedness
of the Company shall first be paid in full, or payment thereof provided for in
money in accordance with its terms, before any payment is made by the Company on
account of the principal or of any premium or interest on the Securities; and
upon any such dissolution or winding-up or liquidation or reorganization, any
payment by the Company, or distribution of assets of the Company of any kind or
character, whether in cash, property or securities, to which the Holders of the
Securities or the Trustee would be entitled to receive from the Company, except
for the provisions of this Article, shall be paid by the Company or by any
receiver, trustee in bankruptcy, liquidating trustee, agent or other Person
making such payment or distribution, or by the Holders of the Securities or by
the Trustee under this Indenture if received by them or it, directly to the
holders of Senior Indebtedness of the Company (pro rata to such holders on the
basis of the respective amounts of Senior Indebtedness held by such holders, as
calculated by the Company) or their representative or representatives, or to the
trustee or trustees under any indenture pursuant to which any instruments
evidencing such Senior Indebtedness may have been issued, as their respective
interests may appear, to the extent necessary to pay such Senior Indebtedness in
full, in money or money's worth, after giving effect to any concurrent payment
or distribution to or for the holders of such Senior Indebtedness, before any
payment or distribution is made to the Holders of the Securities or to the
Trustee.

     In the event that, notwithstanding the foregoing, any payment or
distribution of assets of the Company of any kind or character, whether in cash,
property or securities, prohibited by the foregoing, shall be received by the
Trustee before all Senior Indebtedness of the Company is paid in full, or
provision is made for such payment in money in accordance with its terms, such
payment or distribution shall be held in trust for 

                                      -62-
<PAGE>
 
the benefit of and shall be paid over or delivered to the holders of such Senior
Indebtedness or their representative or representatives, or to the trustee or
trustees under any indenture pursuant to which any instruments evidencing such
Senior Indebtedness may have been issued, and their respective interests may
appear, as calculated by the Company, for application to the payment of all
Senior Indebtedness of the Company, as the case may be, remaining unpaid to the
extent necessary to pay such Senior Indebtedness in full in money in accordance
with its terms, after giving effect to any concurrent payment or distribution to
or for the benefit of the holders of such Senior Indebtedness.

     For purposes of this Article only, the words "cash, property or securities"
shall not be deemed to include shares of stock of the Company as reorganized or
readjusted, or securities of the Company or any other corporation provided for
by a plan of reorganization or readjustment which are subordinated in right of
payment to all Senior Indebtedness which may at the time be outstanding to
substantially the same extent as, or to a greater extent than, the Securities
are so subordinated as provided in this Article.  The consolidation of the
Company with, or the merger of the Company into, another Person or the
liquidation or dissolution of the Company following the conveyance or transfer
of its properties and assets substantially as an entirety to another Person upon
the terms and conditions set forth in Article Eight shall not be deemed a
dissolution, winding-up, liquidation, reorganization, assignment for the benefit
of creditors or marshaling of assets and liabilities of the Company for the
purposes of this Section if the Person formed by such consolidation or into
which the Company is merged or the Person which acquires by conveyance or
transfer such properties and assets substantially as an entirety, as the case
may be, shall, as a part of such consolidation, merger, conveyance or transfer,
comply with the conditions set forth in Article Eight.

     SECTION 1503.  PRIOR PAYMENT TO SENIOR INDEBTEDNESS UPON ACCELERATION OF
SECURITIES.

     In the event that any Securities are declared due and payable before their
Stated Maturity, then and in such event the holders of Senior Indebtedness shall
be entitled to receive payment in full of all amounts due or to become due on or
in respect of all Senior Indebtedness or provision shall be made for such
payment in cash, before the Holders of the Securities are entitled to receive
any payment (including any payment which may be payable by reason of the payment
of any other indebtedness of the Company being subordinated to the payment of
the Securities) by the Company on account of the principal of or any premium or
interest on the Securities or on account of the purchase or other acquisition of
Securities; provided, however, that nothing in this Section shall prevent the
satisfaction of any sinking fund payment in accordance with Article Twelve by
delivering and crediting pursuant to Section 1202 Securities which have been
acquired (upon redemption or otherwise) prior to such declaration of
acceleration or which have been converted pursuant to Article Fourteen.

     In the event that, notwithstanding the foregoing, the Company shall make
any payment to the Trustee or the Holder of any Security prohibited by the
foregoing provisions of this Section, and if such fact shall, at or prior to the
time of such payment, have been made known to the Trustee or, as the case may
be, such Holder, then and in such event such payment shall be paid over and
delivered forthwith to the Company.

     The provisions of this Section shall not apply to any payment with respect
to which Section 1402 would be applicable.

                                      -63-
<PAGE>
 
     SECTION 1504.  NO PAYMENT WHEN SENIOR INDEBTEDNESS IN DEFAULT.

     In the event and during the continuation of any default by the Company in
the payment of principal, premium, interest or any other payment due on any
Senior Indebtedness of the Company, as the case may be, beyond any applicable
grace period with respect thereto, or in the event that the maturity of any
Senior Indebtedness of the Company, as the case may be, has been accelerated
because of a default, or in the event that any other event has occurred and is
continuing on the basis of which the holders of any Senior Indebtedness may
accelerate the maturity thereof or demand payment in full, then, in any such
case, no payment shall be made by the Company with respect to the principal
(including redemption and sinking fund payments) of, or premium, if any, or
interest on the Securities until such default is cured or waived or ceases to
exist or any such acceleration or demand for payment has been rescinded.

     In the event that, notwithstanding the foregoing, any payment shall be
received by the Trustee when such payment is prohibited by the preceding
paragraph of this Section 1504, such payment shall be [paid over or delivered to
the Company] [held in trust for the benefit of, and shall be paid over or
delivered to, the holders of Senior Indebtedness or their respective
representatives, or to the trustee or trustees under any indenture pursuant to
which any of such Senior Indebtedness may have been issued, as their respective
interests may appear, but only to the extent that the holders of the Senior
Indebtedness (or their representative or representatives or a trustee) notify
the Trustee in writing within 90 days of such payment of the amounts then due
and owing on the Senior Indebtedness and only the amounts specified in such
notice to the Trustee shall be paid to the holders of Senior Indebtedness].

     SECTION 1505.  PAYMENT PERMITTED IN CERTAIN SITUATIONS.

     Nothing contained in this Article or elsewhere in this Indenture or in any
of the Securities shall prevent (1) the Company, at any time except during the
pendency of any dissolution, winding-up, liquidation or reorganization of the
Company, whether voluntary or involuntary or any bankruptcy, insolvency,
receivership or other proceedings of the Company referred to in Section 1502 or
under the conditions described in Section 1503 or 1504, from making payments at
any time of principal of, or premium, if any, or interest on the Securities, or
(2) the application by the Trustee of any money deposited with it hereunder to
the payment of or on account of the principal of, or premium, if any, or
interest on the Securities or the retention of such payment by the Holders, if,
at the time of such application by the Trustee, it did not have actual knowledge
that such payment would have been prohibited by the provisions of this Article.

     SECTION 1506.  SUBROGATION TO RIGHTS OF HOLDERS OF SENIOR INDEBTEDNESS.

     Subject to the payment in full of all Senior Indebtedness or the provision
for such payment in cash or cash equivalents or otherwise in a manner
satisfactory to the holders of Senior Indebtedness, the rights of the Holders of
Securities shall be subrogated to the extent of the payments or distributions
made to the holders of such Senior Indebtedness pursuant to the provisions of
this Article (equally and ratably with the holders of indebtedness of the
Company which by its express terms is subordinated to indebtedness of the
Company to substantially the same extent as the Securities are subordinated to
the Senior Indebtedness and is entitled to like rights of subrogation) to the
rights of the holders of 

                                      -64-
<PAGE>
 
such Senior Indebtedness to receive payments and distributions of cash, property
and securities applicable to the Senior Indebtedness until the principal of and
any premium and interest on the Securities shall be paid in full. For purposes
of such subrogation, no payments or distributions to the holders of the Senior
Indebtedness of any cash, property or securities to which the Holders of
Securities or the Trustee would be entitled except for the provisions of this
Article, and no payments over pursuant to the provisions of this Article to or
for the benefit of the holders of Senior Indebtedness by Holders of Securities
or the Trustee, shall, as among the Company, its creditors other than holders of
Senior Indebtedness and the Holders of Securities, be deemed to be a payment or
distribution by the Company to or on account of the Senior Indebtedness.

     SECTION 1507.  PROVISIONS SOLELY TO DEFINE RELATIVE RIGHTS.

     The provisions of this Article are and are intended solely for the purpose
of defining the relative rights of the Holders of Securities on the one hand and
the holders of Senior Indebtedness on the other hand.  Nothing contained in this
Article or elsewhere in this Indenture or in the Securities is intended to or
shall (1) impair, as among the Company, its creditors other than holders of
Senior Indebtedness and the Holders of Securities, the obligation of the
Company, which is absolute and unconditional (and which, subject to the rights
under this Article of the holders of Senior Indebtedness, is intended to rank
equally with all other general obligations of the Company), to pay to the
Holders of Securities the principal of and any premium and interest on the
Securities as and when the same shall become due and payable in accordance with
their terms; or (2) affect the relative rights against the Company of the
Holders of Securities and creditors of the Company, as the case may be, other
than the holders of Senior Indebtedness; or (3) prevent the Trustee or the
Holder of any Security from exercising all remedies otherwise permitted by
applicable law upon default under this Indenture, subject to the rights, if any,
under this Article of the holders of Senior Indebtedness to receive cash,
property and securities otherwise payable or deliverable to the Trustee or such
Holder.

     [SECTION 1508.  TRUSTEE TO EFFECTUATE SUBORDINATION.

     Each Holder of a Security by such Holder's acceptance thereof authorizes
and directs the Trustee on such Holder's behalf to take such action as may be
necessary or appropriate to effectuate the subordination provided in this
Article and appoints the Trustee such Holder's attorney-in-fact for any and all
such purposes.]

     SECTION 1509.  NO WAIVER OF SUBORDINATION PROVISIONS

     No right of any present or future holder of any Senior Indebtedness to
enforce subordination as herein provided shall at any time in any way be
prejudiced or impaired by any act or failure to act on the part of the Company
or by any act or failure to act, in good faith, by any such holder, or by any
noncompliance by the Company with the terms, provisions and covenants of this
Indenture, regardless of any knowledge thereof any such holder may have or be
otherwise charged with.

     Without in any way limiting the generality of the foregoing paragraph, the
holders of Senior Indebtedness may, at any time and from time to time, without
the consent of or notice to the Trustee or the Holders of Securities, without
incurring responsibility to the Holders of Securities and without impairing or
releasing the subordination provided in this Article or the obligations
hereunder of the Holders of Securities to the holders of Senior 

                                      -65-
<PAGE>
 
Indebtedness do any one or more of the following: (1) change the manner, place
or terms of payment or extend the time of payment of, or renew or alter, Senior
Indebtedness or otherwise amend or supplement in any manner Senior Indebtedness
or any instrument evidencing the same or any agreement under which Senior
Indebtedness is outstanding; (2) sell, exchange, release or otherwise deal with
any property pledged, mortgaged or otherwise securing Senior Indebtedness; (3)
release any Person liable in any manner for the collection of Senior
Indebtedness; and (4) exercise or refrain from exercising any rights against the
Company and any other Person.

     SECTION 1510.  NOTICE TO TRUSTEE. 

     The Company shall give prompt written notice to a Responsible Officer of
the Trustee of any fact known to the Company which would prohibit the making of
any payment to or by the Trustee in respect of any Securities pursuant to the
provisions of this Article. Notwithstanding the provisions of this Article or
any other provision of this Indenture, the Trustee shall not be charged with
knowledge of the existence of any facts which would prohibit the making of any
payment to or by the Trustee in respect of any Securities pursuant to the
provisions of this Article, unless and until a Responsible Officer of the
Trustee shall have received written notice thereof from the Company or a holder
or holders of Senior Indebtedness or from any trustee therefor; and, prior to
the receipt of any such written notice, the Trustee, subject to the provisions
of Section 602, shall be entitled in all respects to assume that no such facts
exist; provided, however, that if the Trustee shall have not received the notice
provided for in this Section at least two business days prior to the date upon
which by the terms hereof any money may become payable for any purpose
(including, without limitation, the payment of the principal of or any premium
or interest on any Securities), then, anything herein contained to the contrary
notwithstanding, the Trustee shall have full power and authority to receive such
money and to apply the same to the purposes for which they were received, and
shall not be affected by any notice to the contrary that may be received by it
within two Business Days prior to such date.

     Subject to the provisions of Section 602, the Trustee shall be entitled to
rely on the delivery to it of a written notice by a Person representing himself
to be a holder of Senior Indebtedness (or a trustee therefor) to establish that
such notice has been given by a holder of Senior Indebtedness (or a trustee
therefor).  In the event that the Trustee determines in good faith that further
evidence is required with respect to the right of any Person as a holder of
Senior Indebtedness to participate in any payment or distribution pursuant to
this Article, the Trustee may request such Person to furnish evidence to the
reasonable satisfaction of the Trustee as to the amount of Senior Indebtedness
held by such Person, the extent to which such Person is entitled to participate
in such payment or distribution and any other facts pertinent to the rights of
such Person under this Article, and if such evidence is not furnished, the
Trustee may defer any payment to such Person pending judicial determination as
to the right of such Person to receive such payment.

     SECTION 1511.  RELIANCE ON JUDICIAL ORDER OR CERTIFICATE OF LIQUIDATING
AGENT.

     Upon any payment or distribution of assets of the Company referred to in
this Article, the Trustee, subject to the provisions of Section 603, and the
Holders of Securities shall be entitled to conclusively rely upon any order or
decree entered by any court of competent jurisdiction in which such insolvency,
bankruptcy, receivership, liquidation, reorganization, dissolution, winding up
or similar case or proceeding is pending, or a 

                                      -66-
<PAGE>
 
certificate of the trustee in bankruptcy, receiver, liquidating trustee,
custodian, assignee for the benefit of creditors, agent or other Person making
such payment or distribution, delivered to the Trustee or to the Holders of
Securities, for the purpose of ascertaining the Persons entitled to participate
in such payment or distribution, the holders of Senior Indebtedness and other
indebtedness of the Company, as the case may be, the amount thereof or payable
thereon, the amount or amounts paid or distributed thereon and all other facts
pertinent thereto or to this Article.

     SECTION 1512.  TRUSTEE NOT FIDUCIARY FOR HOLDERS OF SENIOR INDEBTEDNESS

     With respect to the holders of Senior Indebtedness, the Trustee undertakes
to perform or to observe only such of its covenants and obligations as are
specifically set forth in this Article, and no implied covenants or obligations
with respect to the holders of such Senior Indebtedness shall be read into this
Indenture against the Trustee.  The Trustee shall not be deemed to owe any
fiduciary duty to the holders of Senior Indebtedness and shall not be liable to
any such holders or creditors if it shall in good faith pay over or distribute
to Holders of Securities or to the Company or to any other Person cash, property
or securities to which any holders of Senior Indebtedness shall be entitled by
virtue of this Article or otherwise.

     SECTION 1513.  RIGHTS OF TRUSTEE AS HOLDER OF SENIOR INDEBTEDNESS,
PRESERVATION OF TRUSTEE'S RIGHTS.

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

     Nothing in this Article shall apply to claims of, or payments to, the
Trustee under or pursuant to Section 607.

     SECTION 1514.  ARTICLE APPLICABLE TO PAYING AGENTS.

     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 shall in such case (unless the context otherwise requires)
be construed as extending to and including such Paying Agent within its meaning
as fully for all intents and purposes as if such Paying Agent were named in this
Article in addition to or in place of the Trustee; provided, however, that
Section 1413 shall not apply to the Company or any Affiliate of the Company if
it or such Affiliate acts as Paying Agent.

     SECTION 1515.  CERTAIN CONVERSIONS DEEMED PAYMENT.

     For the purposes of this Article only, (1) the issuance and delivery of
junior securities (or cash paid in lieu of fractional shares) upon conversion of
Securities in accordance with Article Fourteen, or pursuant to the terms set
forth in an Officers' Certificate or established in one or more indentures
supplemental hereto in accordance with Section 301, shall not be deemed to
constitute a payment or distribution on account of the principal of or premium
or interest on Securities or on account of the purchase or other acquisition of
Securities, and (2) the payment, issuance or delivery of cash, property or
securities (other than junior securities and cash paid in lieu of fractional
shares) upon 

                                      -67-
<PAGE>
 
conversion of a Security shall be deemed to constitute payment on account of the
principal of such Security. For the purposes of this Section, the term "junior
securities" means (A) shares of any stock of any class of the Company and (B)
securities of the Company which are subordinated in right of payment to all
Senior Indebtedness which may be outstanding at the time of issuance or delivery
of such securities to substantially the same extent as, or to a greater extent
than, the Securities are so subordinated as provided in this Article. Nothing
contained in this Article or elsewhere in this Indenture or in the Securities is
intended to or shall impair, as among the Company, its creditors other than
holders of Senior Indebtedness and the Holders of Securities, the right, which
is absolute and unconditional, of the Holder of any Security to convert such
Security in accordance with Article Fourteen.

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

     IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed, and their respective corporate seals to be hereunto affixed and
attested, all as of the day and year first above written.

                                  NUEVO ENERGY COMPANY



                                  By__________________________________________
                                  

                                  [TRUSTEE]



                                  By___________________________________________

                                      -68-
<PAGE>
 
STATE OF TEXAS      )
                    )  ss:
COUNTY OF HARRIS    )

     On the ____ day of September, 1996, before me personally came
_______________, to me known, who, being by me duly sworn, did depose and say
that he/she is _______________ of Nuevo Energy Company, one of the corporations
described in and which executed the foregoing instrument; that he/she knows the
seal of said corporation; that the seal affixed to said instrument is such
corporate seal; that it was so affixed by authority of the Board of Directors of
said corporation; and that he/she signed his/her name thereto by like authority.



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



STATE OF ____________    )
                         )  ss:
COUNTY OF ___________    )

     On the ____ day of September, 1996, before me personally came
_______________, to me known, who, being by me duly sworn, did depose and say
that he/she is a Trust Officer of [Trustee], one of the corporations described
in and which executed the foregoing instrument; that he/she knows the seal of
said corporation; that the seal affixed to said instrument is such corporate
seal; that it was so affixed by authority of the Board of Directors of said
corporation; and that he/she signed his/her name thereto by like authority.


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

                                      -69-