<PAGE>

                                                                    EXHIBIT 4(J)

________________________________________________________________________________

                                  ALCOA INC.


                                      TO


              CHASE MANHATTAN TRUST COMPANY, National Association


                                  AS TRUSTEE

                              ___________________


                                   INDENTURE

                          DATED AS OF _____ __, 20__



                                $______________


              [(SUBJECT TO AN INCREASE OF UP TO $_____________ IF
                    AN OVER-ALLOTMENT OPTION IS EXERCISED)]


                   __% [CONVERTIBLE] SUBORDINATED DEBENTURES
                             DUE __________, 20__

________________________________________________________________________________
<PAGE>

          Reconciliation and tie between the Trust Indenture Act of 1939
(including cross-references to provisions of Sections 310 to and including 317
which, pursuant to Section 318(c) of the Trust Indenture Act of 1939, as amended
by the Trust Reform Act of 1990, are a part of and govern the Indenture whether
or not physically contained therein) and the Indenture, dated as of _____ __,
20__.

<TABLE>
<CAPTION>
Trust Indenture                                                                     Indenture Section
Act Section
<S>                                                                                 <C>
(S) 310 (a)(1), (2) and (5).......................................................................6.9
        (a)(3).........................................................................Not Applicable
        (a)(4).........................................................................Not Applicable
        (b).......................................................................................6.8
        .........................................................................................6.10
        (c)............................................................................Not Applicable
(S) 311 (a)......................................................................................6.13
        (b)......................................................................................6.13
        (b)(2).................................................................................7.3(a)
        .......................................................................................7.3(a)
(S) 312 (a)...................................................................................... 7.1
        .......................................................................................7.2(a)
        (b)....................................................................................7.2(b)
        (c)....................................................................................7.2(c)
(S) 313 (a)............................................................................7.3(a), 7.3(b)
        (b)....................................................................................7.3(a)
        (c)....................................................................................7.3(a)
        (d)....................................................................................7.3(c)
(S) 314 (a)(1), (2), (3) and (4)..................................................................7.4
        (b)............................................................................Not Applicable
        (c)(1)....................................................................................1.2
        (c)(2)....................................................................................1.2
        (c)(3).........................................................................Not Applicable
        (d)............................................................................Not Applicable
        (e).......................................................................................1.2
        (f)............................................................................Not Applicable
(S) 315 (a)....................................................................................6.1(a)
        (b).......................................................................................6.2
        (c)....................................................................................6.1(b)
        (d)....................................................................................6.1(c)
</TABLE>
<PAGE>

<TABLE>
<S>                                                                                   <C>
        (d)(1).............................................................................6.1(a)(1)
        (d)(2).............................................................................6.1(c)(2)
        (d)(3).............................................................................6.1(c)(3)
        (e).....................................................................................5.14
(S) 316 (a).....................................................................................5.12
        (a)(1)(B)...............................................................................5.13
        (a)(2)........................................................................Not Applicable
        (b)......................................................................................5.8
        (c)...................................................................................1.4(f)
(S) 317 (a)(1)...................................................................................5.3
        (a)(2)...................................................................................5.4
        (b).....................................................................................10.3
(S) 318 (a)......................................................................................1.7
</TABLE>

Note:  This  reconciliation and tie shall not, for any purpose, be deemed to
be a part of the [Convertible] Subordinated Indenture.
<PAGE>

                               TABLE OF CONTENTS
                               -----------------

<TABLE>
<CAPTION>
                                                                                                 PAGE
                                                                                                 ----
                                                             ARTICLE I

                                      DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION
<S>                                                                                                <C>
Section 1.1       Definitions.......................................................................3
Section 1.2       Compliance Certificate and Opinions..............................................16
Section 1.3       Forms of Documents Delivered to Trustee..........................................17
Section 1.4       Acts of Holders..................................................................17
Section 1.5       Notices, Etc. to Trustee and Company.............................................19
Section 1.6       Notice to Holders; Waiver........................................................19
Section 1.7       Conflict with Trust Indenture Act................................................20
Section 1.8       Effect of Headings and Table of Contents.........................................20
Section 1.9       Successors and Assigns...........................................................20
Section 1.10      Separability Clause..............................................................20
Section 1.11      Benefits of Indenture............................................................20
Section 1.12      Governing Law....................................................................21
Section 1.13      Non-Business Days................................................................21

                                                            ARTICLE II

                                                          DEBENTURE FORM

Section 2.1       Forms Generally..................................................................21
Section 2.2       Form of Face of Debenture........................................................22
Section 2.3       Form of Reverse of Debenture.....................................................23
Section 2.4       Additional Provisions Required in Global Security................................31
Section 2.5       Form of Trustee's Certificate of Authentication..................................31
[Section 2.6      Initial Issuance to Property Trustee.............................................32]

                                                            ARTICLE III

                                                          THE DEBENTURES

Section 3.1       Amount of Debentures............................................................ 32
Section 3.2       Denominations................................................................... 32
</TABLE>

                                       i

<PAGE>

<TABLE>
<CAPTION>
                                                                            PAGE
                                                                            ----
<S>                                                                         <C>
Section 3.3   Execution, Authentication, Delivery and Dating................ 32
Section 3.4   Temporary Debentures.......................................... 33
Section 3.5   Registration, Transfer and Exchange........................... 33
Section 3.6   Mutilated, Destroyed, Lost and Stolen Debentures.............. 35
Section 3.7   Payment of Interest; Interest Rights Preserved................ 36
Section 3.8   Persons Deemed Owners......................................... 37
Section 3.9   Cancellation.................................................. 37
Section 3.10  Computation of Interest....................................... 38
Section 3.11  Deferrals of Interest Payment Dates........................... 38
Section 3.12  Right of Set-off.............................................. 39
Section 3.13  Agreed Tax Treatment.......................................... 39
Section 3.14  CUSIP Numbers................................................. 39
Section 3.15  Global Security............................................... 40

                                  ARTICLE IV

                   SATISFACTION AND DISCHARGE OF INDENTURE;
                               UNCLAIMED MONEYS

Section 4.1   Satisfaction and Discharge of Indenture....................... 42
Section 4.2   Application by Trustee of Funds Deposited for Payment of
              Debentures.................................................... 44
Section 4.3   Repayment of Moneys Held by Paying Agent...................... 45
Section 4.4   Return of Moneys Held by Trustee and Paying Agent Unclaimed
              for Three Years............................................... 45
Section 4.5   Indemnity for Government Obligations.......................... 45

                                   ARTICLE V

                                   REMEDIES

Section 5.1   Events of Default............................................. 46
Section 5.2   Acceleration of Maturity; Rescission and Annulment............ 47
Section 5.3   Collection of Indebtedness and Suits for Enforcement by
              Trustee....................................................... 48
Section 5.4   Trustee May File Proofs of Claim.............................. 49
</TABLE>

                                      ii
<PAGE>

<TABLE>
<CAPTION>
                                                                                              PAGE
                                                                                              ----

<S>                                                                                           <C>
Section 5.5       Trustee May Enforce Claim Without Possession of
                  Debentures...................................................................50
Section 5.6       Application of Money Collected...............................................51
Section 5.7       Limitation on Suits..........................................................51
Section 5.8       Unconditional Right of Holders to Receive Principal,
                  Premium and Interest.........................................................52
Section 5.9       Restoration of Rights and Remedies...........................................53
Section 5.10      Rights and Remedies Cumulative...............................................53
Section 5.11      Delay or Omission Not Waiver.................................................53
Section 5.12      Control by Holders...........................................................53
Section 5.13      Waiver of Past Defaults......................................................54
Section 5.14      Undertaking for Costs........................................................55
Section 5.15      Waiver of Usury, Stay, or Extension Laws.....................................55

                                               ARTICLE VI

                                              THE TRUSTEE

Section 6.1       Certain Duties and Responsibilities..........................................56
Section 6.2       Notice of Defaults...........................................................57
Section 6.3       Certain Rights of Trustee....................................................58
Section 6.4       Not Responsible for Recitals or Issuance of Debentures.......................59
Section 6.5       May Hold Debentures..........................................................59
Section 6.6       Money Held in Trust..........................................................59
Section 6.7       Compensation and Reimbursement...............................................59
Section 6.8       Disqualification; Conflicting Interests......................................60
Section 6.9       Corporate Trustee Required; Eligibility......................................61
Section 6.10      Resignation and Removal; Appointment of Successor............................61
Section 6.11      Acceptance of Appointment by Successor.......................................63
Section 6.12      Merger, Conversion, Consolidation or Succession to
                  Business.....................................................................64
Section 6.13      Preferential Collection of Claims Against Company............................64
Section 6.14      Appointment of Authenticating Agent..........................................64
</TABLE>

                                      iii
<PAGE>

<TABLE>
<CAPTION>
                                                                           PAGE
                                                                           ----

                                  ARTICLE VII

               HOLDERS LISTS AND REPORTS BY TRUSTEE AND COMPANY
<S>                                                                        <C>
Section 7.1   Company to Furnish Names and Addresses of Holders............ 67
Section 7.2   Preservation of Information; Communications to Holders....... 67
Section 7.3   Reports by Trustee........................................... 67
Section 7.4   Reports by Company........................................... 68

                                 ARTICLE VIII

             CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

Section 8.1   Company May Consolidate, Etc., Only on Certain Terms......... 68
Section 8.2   Successor Corporation Substituted............................ 69

                                  ARTICLE IX

                            SUPPLEMENTAL INDENTURES

Section 9.1   Supplemental Indentures Without Consent of Holders........... 70
Section 9.2   Supplemental Indentures with Consent of Holders.............. 72
Section 9.3   Execution of Supplemental Indentures......................... 73
Section 9.4   Effect of Supplemental Indentures............................ 73
Section 9.5   Conformity with Trust Indenture Act.......................... 73
Section 9.6   Reference in Debentures to Supplemental Indentures........... 73
</TABLE>

                                   ARTICLE X

                                   COVENANTS

Section 10.1  Payment of Principal, Premium and Interest................... 74
Section 10.2  Maintenance of Office or Agency.............................. 74
Section 10.3  Money for Debenture Payments to Be Held in Trust............. 75
Section 10.4  Payment of Taxes and Other Claims............................ 76
Section 10.5  Statement as to Compliance................................... 77
Section 10.6  Waiver of Certain Covenants.................................. 77
Section 10.7  Additional Sums.............................................. 77
Section 10.8  Additional Covenants......................................... 78
Section 10.9  Payment of Expenses of the Trust............................. 79

                                      iv
<PAGE>

<TABLE>
<CAPTION>
                                                                            PAGE
                                                                            ----

                                  ARTICLE XI

                     REDEMPTION OR EXCHANGE OF DEBENTURES
<S>                                                                         <C>
Section 11.1      Election to Redeem; Notice to Trustee..................... 79
Section 11.2      Selection of Debentures to Be Redeemed.................... 79
Section 11.3      Notice of Redemption...................................... 80
Section 11.4      Deposit of Redemption Price............................... 81
Section 11.5      Debentures Payable on Redemption Date..................... 81
Section 11.6      Debentures Redeemed in Part............................... 82
Section 11.7      Mandatory Redemption...................................... 82
Section 11.8      Optional Redemption....................................... 82
[Section 11.9     Exchange of Trust Securities for Debentures............... 83]
Section 11.10     Purchases of Debentures................................... 84

                                  ARTICLE XII

                          SUBORDINATION OF DEBENTURES

Section 12.1      Debentures Subordinate to Senior Debt..................... 85
Section 12.2      Payment Over of Proceeds Upon Dissolution, Etc............ 85
Section 12.3      No Payment When Senior Debt in Default.................... 86
Section 12.4      Payment Permitted If No Default........................... 87
Section 12.5      Subrogation to Rights of Holders of Senior Debt........... 87
Section 12.6      Provisions Solely to Define Relative Rights............... 88
Section 12.7      Trustee to Effectuate Subordination....................... 88
Section 12.8      No Waiver of Subordination Provisions..................... 89
Section 12.9      Notice to Trustee......................................... 89
Section 12.10     Reliance on Judicial Order or Certificate of Liquidating
                  Agent..................................................... 89
Section 12.11     Trustee Not Fiduciary for Holders of Senior Debt.......... 89
Section 12.12     Rights of Trustee as Holder of Senior Debt;
                  Preservation of Trustee's Rights.......................... 90
Section 12.13     Article Applicable to Paying Agents....................... 90
Section 12.14     Certain Conversions or Exchanges Deemed Payment........... 90
Section 12.15     Trust Moneys Not Subordinated............................. 90
</TABLE>

                                        v
<PAGE>

<TABLE>
<CAPTION>
                                                                            PAGE
                                                                            ----
                                 ARTICLE XIII

                          [CONVERSION OF DEBENTURES
<S>                                                                         <C>
Section 13.1      Conversion Rights......................................    91
Section 13.2      Conversion Procedures..................................    91
Section 13.3      Conversion Price Adjustments...........................    94
Section 13.4      Fundamental Change.....................................   100
Section 13.5      Notice of Adjustments of Conversion Price..............   101
Section 13.6      Prior Notice of Certain Events.........................   102
Section 13.7      Dividend or Interest Reinvestment Plans................   103
Section 13.8      Certain Additional Rights..............................   103
Section 13.9      Trustee Not Responsible for Determining
                  Conversion Price or Adjustments........................   104]


[Annex A          Declaration of Trust
Annex B           Amended and Restated Trust Agreement
Annex C           Guarantee Agreement]
</TABLE>

                                      vi
<PAGE>

               [CONVERTIBLE] SUBORDINATED INDENTURE (the "Indenture"), dated as
     of _____ __, 20__ between Alcoa Inc., A Pennsylvania corporation
     (hereinafter called the "Company") having its principal office at 201
     Isabella Street, Pittsburgh, Pennsylvania, 15212-5858, and Chase Manhattan
     Trust Company, National Association, a national banking association
     existing under the laws of the United States of America, as Trustee
     (hereinafter called the "Trustee").

                            RECITALS OF THE COMPANY

               WHEREAS, for its lawful corporate purposes, the Company has duly
     authorized the execution and delivery of this Indenture to provide for the
     issuance of its __% [Convertible] Debentures Due _______, 20__(the
     "Debentures"), of substantially the tenor and amount hereinafter set forth;

               WHEREAS, to provide the terms and conditions upon which the
     Debentures are to be authenticated, issued and delivered, the Company has
     duly authorized the execution of this Indenture; and,

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

               NOW, THEREFORE, in consideration of the premises and the
     purchase of the Debentures by the holders thereof, it is mutually
     covenanted and agreed as follows for the equal and ratable benefit of the
     holders of Debentures:

















<PAGE>

                                   ARTICLE I

          DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

          Section 1.1  Definitions. For all purposes of this Indenture, except
                       -----------
as otherwise expressly provided or unless the context otherwise requires:

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

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

               (c)  all accounting terms not otherwise defined herein have the
meanings assigned to them in accordance with generally accepted accounting
principles, and the term "generally accepted accounting principles" with respect
to any computation required or permitted hereunder shall mean such accounting
principles which are generally accepted at the date or time of such computation;
and

               (d)  the words "herein" 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 1.4.

          ["Additional Amount" means, [with respect to the Trust Securities],
the amount of Additional Interest paid by the Company on the Debentures.]

          "Additional Interest" means the interest, if any, that shall accrue on
any interest on the Debentures that is in arrears for more than one interest
payment period or not paid during any Extension Period, which in either case
shall accrue at the stated rate per annum specified or determined as specified
in such Debenture and compounded quarterly.

          ["Additional Sums" has the meaning specified in Section 10.5.

                                       3
<PAGE>

               ["Additional Taxes" means the sum of any additional taxes, duties
          and other governmental charges to which the Trust has become subject
          from time to time as a result of a Tax Event.]

               "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; provided, however,
          that an Affiliate of the Company shall not be deemed to include the
          Trust. 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.

               ["Applicable Price" means (i) in the case of a Non-Stock
          Fundamental Change in which the holders of the Common Stock receive
          only cash, the amount of cash received by the holder of one share of
          Common Stock and (ii) in the event of any other Non-Stock Fundamental
          Change or any Common Stock Fundamental Change, the average of the
          Closing Prices for the Common Stock during the ten trading days prior
          to and including the record date for the determination of the

                                       4
<PAGE>

          holders of Common Stock entitled to receive such securities, cash, or
          other property in connection with such Non-Stock Fundamental Change or
          Common Stock Fundamental Change or, if there is no such record date,
          the date upon which the holders of the Common Stock shall have the
          right to receive such securities, cash, or other property, in each
          case as adjusted in good faith by the Company to appropriately reflect
          any of the events referred to in Section 13.4.]

               "Authenticating Agent" means any Person authorized by the Trustee
          pursuant to Section 6.14 to act on behalf of the Trustee to
          authenticate Debentures .

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

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

               "Business Day" means any day other than a Saturday or Sunday or a
          day on which banking institutions in the City of New York are
          authorized or required by law or executive order to remain closed or a
          day on which the corporate trust office of the Property Trustee, or
          the Corporate Trust Office of the Trustee, is closed for business.

               ["Closing Price" means on any day the reported last sale price on
          such day or, in case no sale takes place on such day, the average of
          the reported closing bid and asked prices in each case on the NYSE
          Consolidated Transactions Tape or, if the stock is not listed or
          admitted to trading on the NYSE, on the principal national securities
          exchange on which such stock is listed or admitted to trading or, if
          not listed or admitted to trading on any national securities exchange,
          or the Nasdaq National Market, or, if the stock is not quoted or
          admitted to trading on such quotation system, on the principal
          quotation system on which the stock may be listed or admitted to
          trading or quoted, or, if not listed or admitted to trading or quoted
          on any national securities exchange or quotation system, the average
          of the closing bid and asked prices as furnished by any NYSE member
          firm, selected by the Trustee in good faith for that purpose.]

                                       5
<PAGE>

               "Commission" means the Securities and Exchange Commission, as
          from time to time constituted, created under the Securities Exchange
          Act of 1934, 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 on such date.

               "Common Securities" has the meaning specified in the first
          recital of this Indenture.

               ["Common Stock" means common stock, par value $1.00, of the
          Company.]

               ["Common Stock Fundamental Change" means any Fundamental Change
          in which more than 50% of the value (as determined in good faith by
          the Board of Directors) of the consideration received by holders of
          Common Stock consists of common stock that for each of the ten
          consecutive trading days prior to the record date for the
          determination of the holders of Common Stock entitled to receive such
          common stock or, if there is no such record date, the date on which
          the holders of the Common Stock shall have the right to receive such
          Common Stock, has been admitted for listing or admitted for listing
          subject to notice of issuance on a national securities exchange or
          quoted on the Nasdaq National Market; provided, however, that a
          Fundamental Change shall not be a Common Stock Fundamental Change
          unless either (i) the Company continues to exist after the occurrence
          of such Fundamental Change and the outstanding Preferred Securities
          continue to exist as outstanding Preferred Securities or (ii) not
          later than the occurrence of such Fundamental Change, the outstanding
          Preferred Securities are converted into or exchanged for shares of
          convertible preferred stock of an entity succeeding to the business of
          the Company or a Subsidiary thereof, which convertible preferred stock
          has powers, preferences, and relative, participating, optional, or
          other rights, and qualifications, limitations, and restrictions,
          substantially similar to those of the Preferred Securities.]

               "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 Office" means the office or agency to be maintained by
          the Company pursuant to Section 10.2.

                                       6
<PAGE>

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

              ["Conversion Agent" has the meaning specified in Section 13.2.

               "Conversion Date" has the meaning specified in Section 13.2.

               "Conversion Price" has the meaning specified in Section 13.1.]

               "Corporate Trust Office" means the principal office of Chase
          Manhattan Trust Company, National Association located at One Oxford
          Centre, Suite 1100, 301 Grant Street, Pittsburgh, Pennsylvania, or
          such other location at which at any particular time corporate trust
          business of the Trustee shall be administered.

               ["Current Market Price," with respect to Common Stock, means for
          any day the last reported sale price, regular way, on such day, or, if
          no sale takes place on such day, the average of the reported closing
          bid and asked prices on such day, regular way, in either case as
          reported on the NYSE Composite Transactions Tape, or, if Common Stock
          is not listed or admitted to trading on the NYSE on such day, on the
          principal national securities exchange on which Common Stock is listed
          or admitted to trading, if Common Stock is listed on a national
          securities exchange, or the Nasdaq National Market, or, if Common
          Stock is not quoted or admitted to trading on such quotation system,
          on the principal quotation system on which the Common Stock may be
          listed or admitted to trading or quoted, or, if not listed or admitted
          to trading or quoted on any national securities exchange or quotation
          system, the average of the closing bid and asked prices of Common
          Stock in the over-the-counter market on the day in question as
          reported by the National Quotation Bureau Incorporated, or a similar
          generally accepted reporting service, or, if not so

                                       7
<PAGE>

          available in such manner, as furnished by any NYSE member firm
          selected from time to time by the Board of Directors for that purpose
          or, if not so available in such manner, as otherwise determined in
          good faith by the Board of Directors.]

               "Debentures" or "Debenture" means any debt securities or debt
          security, as the case may be, authenticated and delivered under this
          Indenture.

               "Debt" means, with respect to any Person, whether recourse is to
          all or a portion of the assets of such Person and whether or not
          contingent, (i) every obligation of such Person for money borrowed;
          (ii) every obligation of such Person evidenced by bonds, debentures,
          notes or other similar instruments, including obligations incurred in
          connection with the acquisition of property, assets or businesses;
          (iii) every reimbursement obligation of such Person with respect to
          letters of credit, bankers' acceptances or similar facilities issued
          for the account of such Person; (iv) every obligation of such Person
          issued or assumed as the deferred purchase price of property or
          services (but excluding trade accounts payable or accrued liabilities
          arising in the ordinary course of business); (v) every capital lease
          obligation of such Person; and (vi) every obligation of the type
          referred to in clauses (i) through (v) of another Person and all
          dividends of another Person the payment of which, in either case, such
          Person has guaranteed or for which such Person is responsible or
          liable, directly or indirectly, as obligor or otherwise.

               "Defaulted Interest" has the meaning specified in Section 3.7.

               ["Delaware Trustee" means Chase Manhattan Bank Delaware.]

               "Depositary" means, with respect to the Debentures issuable or
          issued in whole or in part in the form of one or more Global
          Securities, the Person designated as Depositary by the Company (or
          any successor thereto).

               "Dollar" means the currency of the United States of America as at
          the time of payment is legal tender for the payment of public and
          private debts.

                                       8
<PAGE>

               "Events of Default" has the meaning specified in Article 5.

              ["Expiration Time" has the meaning specified in Section 13.3(e).]

               "Extension Period" has the meaning specified in Section 3.11.

               ["Fundamental Change" means the occurrence of any Transaction or
          event in connection with a plan pursuant to which all or substantially
          all of the Common Stock shall be exchanged for, converted into,
          acquired for, or constitute solely the right to receive securities,
          cash, or other property (whether by means of an exchange offer,
          liquidation, tender offer, consolidation, merger, combination,
          reclassification, recapitalization, or otherwise), provided, that, in
          the case of a plan involving more than one such Transaction or event,
          for purposes of adjustment of the conversion price, such Fundamental
          Change shall be deemed to have occurred when substantially all of the
          Common Stock shall be exchanged for, converted into, or acquired for
          or constitute solely the right to receive securities, cash, or other
          property, but the adjustment shall be based upon consideration that a
          holder of Common Stock received in such Transaction or event as a
          result of which more than 50% of the Common Stock shall have been
          exchanged for, converted into, or acquired for or constitute solely
          the right to receive securities, cash, or other property.]

               "Global Security" means a Debenture in the form prescribed in
          Section 2.4 evidencing all or part of the Debentures, issued to the
          Depositary or its nominee, and registered in the name of such
          Depositary or its nominee.

               "Government Obligations" means securities which are (i) direct
          obligations of the United States of America for the payment of which
          its full faith and credit is pledged or (ii) obligations of any Person
          controlled or supervised by and acting as an agency or instrumentality
          of the United States of America the payment of which is
          unconditionally guaranteed as a full faith and credit obligation by
          the United States of America, which, in either case are not callable
          or redeemable at the option of the issuer thereof. Government
          Obligations shall include a depositary receipt issued by a bank or
          trust company as custodian with respect to any such Government
          Obligation or a specific payment of interest on or principal of any
          such Government Obligation held by such custodian for the account of
          the holder of a depositary receipt; provided, however, that (except as
          required by law) such custodian is not authorized to make any
          deduction from the amount payable to the holder of such depositary
          receipt from any amount received by the custodian in respect of

                                       9
<PAGE>

          the Government Obligation or the specific payment of interest on or
          principal of the Government Obligation evidenced by such depositary
          receipt.

              ["Guarantee" means the guarantee by the Company of distributions
          on the Preferred Securities of the Trust to the extent provided in the
          Guarantee Agreement, substantially in the form attached hereto as
          Annex C, as amended from time to time.]

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

               "Indenture" means this instrument as originally executed or as it
          may from time to time be supplemented or amended by one or more
          indentures supple mental hereto entered into pursuant to the
          applicable provisions hereof.

               "Interest Payment Date" means as to the Debentures the Stated
          Maturity of an installment of interest on such Debentures.

               "Interest Rate" means the rate of interest specified or
          determined as specified in each Debenture as being the rate of
          interest payable on such Debenture.

               ["Investment Company Event" means, the receipt by the Property
          Trustee, on behalf of the Trust, of an Opinion of Counsel, rendered by
          a law firm having a recognized national tax and securities practice
          (which opinion shall not have been rescinded by such law firm), to the
          effect that, as a result of the occurrence of a change in law or
          regulation or a change in interpretation or application of law or
          regulation by any legislative body, court, governmental agency or
          regulatory authority (a "Change in 1940 Act Law"), there is more than
          an insubstantial risk that the Trust is or will be considered an
          "investment company" that is required to be registered under the 1940
          Act, which Change in 1940 Act Law becomes effective on or after the
          date of original issuance of the Preferred Securities of the Trust.]

               "Maturity" when used with respect to the Debentures, means the
          date on which the principal of the Debentures become due and payable
          as herein pro vided, whether at the Stated Maturity or by declaration
          of acceleration, call or redemption or otherwise.

                                      10
<PAGE>

               "1940 Act" means the Investment Company Act of 1940, as amended.

              ["Non Book-Entry Preferred Securities" has the meaning specified
          in Section 3.1 5.]

              ["Non-Stock Fundamental Change" means any Fundamental Change other
          than a Common Stock Fundamental Change.

               "Notice of Conversion" means the notice given by a holder of Pre-
          ferred Securities to the Conversion Agent directing the Conversion
          Agent to exchange such Preferred Securities for Debentures and to
          convert such Debentures into Common Stock on behalf of such holder.
          Such notice is substantially in the form set forth in Exhibit E to the
          Trust Agreement.]

               "Notice of Default" has the meaning specified in Section 5.1(c).

               [NYSE" means The New York Stock Exchange Inc..]

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

               "Opinion of Counsel" means a written opinion of counsel, who may
          be counsel for the Company, [the Trust,] or the Trustee, but who may
          be an employee thereof, and who shall be reasonably acceptable to the
          Trustee.

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

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

                    (ii)  Debentures for the payment of which money in the
               necessary amount has been theretofore irrevocably deposited with
               the Trustee or any Paying Agent in trust for the Holders of such
               Debentures; and

                    (iii) Debentures in substitution for or in lieu of which
               other Debentures have been authenticated and delivered or which
               have been

                                      11
<PAGE>

     paid pursuant to Section 3.6, or which have been converted into Common
     Stock pursuant to Section 13.1, unless proof satisfactory to the Trustee is
     presented that any Debentures are held by Holders in whose hands such
     Debentures are valid, binding and legal obligations of the Company;

provided, however, that in determining whether the Holders of the requisite
principal amount of Outstanding Debentures have given any request, demand,
authorization, direction, notice, consent or waiver hereunder, Debentures owned
by the Company or any other obligor upon the Debentures or any Affiliate of the
Company or such other obligor shall be disregarded and deemed not to be
outstanding, except that, in determining whether the Trustee shall be protected
in relying upon any such request, demand, authorization, direction, notice,
consent or waiver, only Debentures which the Trustee actually knows to be so
owned shall be so disregarded.  Debentures 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
Debentures and that the pledgee is not the Company or any other obligor upon the
Debentures or any Affiliate of the Company or such other obligor. Upon request
of the Trustee, the Company shall furnish to the Trustee promptly an Officers'
Certificate listing and identifying all Debentures, if any, known by the Company
to be owned or held by or for the account of the Company, or any other obligor
on the Debentures or any Affiliate of the Company or such obligor, and, subject
to the provisions of Section 6.1, the Trustee shall be entitled to accept such
Officers' Certificate as conclusive evidence of the facts therein set forth and
of the fact that all Debentures not listed therein are Outstanding for the
purpose of any such determination.

          "Paying Agent" means the Trustee or any Person or Persons designated
by the Company at any time to pay the principal of or interest on any Debentures
on behalf of the Company. The Company may, at any time, rescind the designation
of any Paying Agent.

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

          "Predecessor Debenture" of any particular Debenture means every
previous Debenture evidencing all or a portion of the same debt as that
evidenced by such particular Debenture, and, for the purposes of this
definition, any Debenture authenticated and delivered under Section 3.6 in lieu
of a lost, destroyed or stolen

                                      12
<PAGE>

Debenture shall be deemed to evidence the same debt as the lost, destroyed or
stolen Debenture.

          ["Preferred Securities" means __ % [Convertible] Preferred Securities
with a liquidation amount of $50 per Preferred Security having an aggregate
liquidation amount with respect to the assets of the Trust of $ _______ [ or
$ _______ if the over-allotment option is exercised).]

          "Proceeding" has the meaning specified in Section 12.2.

          ["Property Trustee" means, in respect of the Trust, the commercial
bank or trust company identified as the "Property Trustee" in the Trust
Agreement, solely in its capacity as Property Trustee of the Trust under the
Trust Agreement and not in its individual capacity, or its successor in interest
in such capacity, or any successor property trustee appointed as therein
provided.]

          ["Purchased Shares" has the meaning specified in Section 13.4(e).]

          ["Purchaser Stock Price" means, with respect to any Common Stock
Fundamental Change, the average of the Closing Prices for the common stock
received in such Common Stock Fundamental Change for the ten consecutive trading
days prior to and including the record date for the determination of the holders
of Common Stock entitled to receive such common stock or if there is no such
record date, the date on which the holders of Common Stock shall have the right
to receive such common stock, as adjusted in good faith by the Company to
appropriately reflect any of the events referred to in Section 13.4.]

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

           "Redemption Price" has the meaning specified in Section 11.3.

          ["Reference Date" has the meaning specified in Section 13.4(c).]

          ["Reference Market Price" initially means $______ (which is an amount
equal to 66 2/3% of the reported last sale price for the Common Stock on the
NYSE Consolidated Transactions Tape on ___________, 20__), and in the event of
any adjustment of the Conversion Price other than as a result of a Non-Stock
Fundamental Change, the Reference Market Price shall also be adjusted by the
Company so that the ratio of the Reference Market Price to the Conversion Price

                                      13
<PAGE>

after giving effect to any such adjustment shall always be the same as the ratio
of the initial Reference Market Price to the initial Conversion Price of the
Debentures.]

          "Regular Record Date" means for the interest payable on any Interest
Payment Date the fifteenth day (whether or not a Business Day) next preceding
such Interest Payment Date.

          "Responsible Officer" when used with respect to the Trustee means any
officer of the Trustee assigned by the Trustee from time to time to administer
this Indenture, or any other officer to whom such matters may be
referred.

          ["Rights" has the meaning specified in Section 13.2(f).]

          "Securities Register" and "Securities Registrar" have the respective
meanings specified in Section 3.5.

          "Senior Debt" 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 whether or
not such claim for post-petition interest is allowed in such proceeding), on
Debt of the Company, whether incurred on or prior to the date of the 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 of payment to the Debentures.

          ["Special Event" means a Tax Event or an Investment Company Event.]

          "Special Record Date" for the payment of any Defaulted Interest means
a date fixed by the Trustee pursuant to Section 3.7.

          "Stated Maturity" when used with respect to the Debentures or any
installment of principal thereof or interest thereon means the date specified in
the

                                      14
<PAGE>

Debentures as the fixed date on which the principal of the Debentures or such
installment of interest is due and payable.

          "Subsidiary" means any corporation of which at the time of
determination the Company and/or one or more Subsidiaries owns or controls
directly or indirectly more than 50% of the outstanding shares of voting stock.
For purposes of this definition, "voting stock" means stock which 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.

          ["Tax Event" means the receipt by the Property Trustee, on behalf of
the Trust, of an Opinion of Counsel, rendered by a law firm having a national
tax and securities practice (which opinion shall not have been rescinded by such
law firm), to the effect that, as a result of any amendment to, or change
(including any announced prospective change) in, the laws (or any regulations
thereunder) of the United States or any political subdivision or taxing
authority thereof or therein affecting taxation, or as a result of any official
administrative pronouncement or judicial decision interpreting or applying such
laws or regulations, which amendment or change is effective or such
pronouncement or decision is announced on or after the date of issuance of the
Preferred Securities under the Trust Agreement, there is more than an
insubstantial risk in each case after the date hereof that (i) the Trust is, or
will be within 90 days of the date thereof, subject to United States Federal
income tax with respect to income received or accrued on the Debentures, (ii)
interest payable by the Company on the Debentures is not, or will not be, within
90 days after the date thereof,  deductible, in whole or in part, for United
States Federal income tax purposes or (iii) the Trust is, or will be within 90
days after the date thereof, subject to more than a de minimis amount of other
taxes, duties, assessments or other governmental charges.]

          ["Transaction" has the meaning specified in Section 13.4(a).]

          ["Trust" means Alcoa Trust I, a Delaware business trust formed under
the Trust Agreement.]

          ["Trust Agreement" means the Declaration of Trust substantially in the
form attached hereto as Annex A, as amended by the Amended and Restated Trust
Agreement substantially in the form attached hereto as Annex B, as amended from
time to time.]

                                      15
<PAGE>

          "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 if
at any time there is more than one such Person.

          "Trust Indenture Act" means the Trust Indenture Act of 1939 (15 U.S.C.
(S)(S) 77aaa-77bbb), as amended and as in effect on the date as of this
Indenture.

          ["Trust Securities" means the Common Securities and Preferred
Securities.]

          "Vice President" when used with respect to the Company, 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 1.2    Compliance Certificate 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 an
Officers' Certificate stating that all conditions precedent (including
covenants, compliance with which constitutes a condition precedent), if any,
provided for in this Indenture relating to the proposed action have been
complied with and an Opinion of Counsel stating that in the opinion of such
counsel all such conditions precedent (including covenants compliance with which
constitutes a condition precedent), if any, have been complied with, except that
in the case of any such application or request as to which the furnishing of
such documents is specifically required by any provision of this Indenture
relating to such particular application or request, no additional certificate or
opinion need be furnished.

          Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture (other than certificates
provided pursuant to Section 10.5) shall include:

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

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

                                      16
<PAGE>

               (c) 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

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

          Section 1.3    Forms 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 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 1.4 Acts of Holders. (a) Any request, demand, authorization,
                      ---------------
direction, notice, consent, waiver or other action provided by this Indenture to
be given to or taken by Holders may be embodied in and evidenced by one or more
instruments of substantially similar tenor signed by such Holders in person or
by an
                                      17
<PAGE>

agent duly appointed in writing; and, except as herein otherwise expressly
provided, such action shall become effective when such instrument or instruments
is or are delivered to the Trustee, and, where it is hereby expressly required,
to the Company. Such instrument or instruments (and the action embodied therein
and evidenced thereby) are herein sometimes referred to as the "Act" of the
Holders signing such instrument or instruments. Proof of execution of any such
instrument or of a writing appointing any such agent shall be sufficient for any
purpose of this Indenture and (subject to Section 6.1) conclusive in favor of
the Trustee and the Company and any agent of the Trustee or the Company, if made
in the manner provided in this Section.

               (b) 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 the certificate of any 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 Person acting in other than his individual capacity, such
certificate or affidavit shall also constitute sufficient proof of his
authority.

               (c) The fact and date of the execution by any Person 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 and in
accordance with such reasonable rules as the Trustee may determine.

               (d) The ownership of Debentures shall be proved by the Securities
Register.

               (e) Any request, demand, authorization, direction, notice,
consent, waiver or other action by the Holder of any Debenture shall bind every
future Holder of the same Debenture and the Holder of every Debenture issued
upon the transfer thereof or in exchange therefor or in lieu thereof in respect
of anything done 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
Debenture.

               (f) The Company may, but shall not be obligated to, fix a record
date for the purpose of determining the Holders entitled to take any action
under this Indenture by vote or consent. If a record date is fixed, those
Persons who

                                      18
<PAGE>

were Holders at such record date (or their duly designated proxies), and only
those Persons, shall be entitled to take such action by vote or consent or to
revoke any vote or consent previously given, whether or not such Persons
continue to be Holders after such record date.

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

          Section 1.5    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

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

               (b) the Company by the Trustee or by any Holder shall be
sufficient for every purpose (except as otherwise provided in Section 5.1
hereof) hereunder if in writing 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 1.6    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 the
address of such Holder as it appears in the Securities Register on the date such
notice is mailed, which shall be not later than the latest date, and not earlier
than the earliest date, prescribed for the giving of such notice.  In any case
where notice to Holders is given by mail, neither the failure to mail such
notice, nor any defect in any notice so mailed, to any particular Holder shall
affect the sufficiency of such notice with respect to other Holders.  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

                                      19
<PAGE>

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 1.7    Conflict with Trust Indenture Act.  If any provision of
                         ---------------------------------
this Indenture limits, qualifies or conflicts with a provision of the Trust
Indenture Act that is required under such act to be a part of and govern this
Indenture, the latter provision shall control.  If any provision of this
Indenture modifies or excludes any provision of the Trust Indenture Act that may
be so modified or excluded, the former provision shall be deemed to apply.

          Section 1.8    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 1.9    Successors and Assigns.  All covenants and agreements
                         ----------------------
in this Indenture by the Company shall bind its successors and assigns, whether
so expressed or not.

          Section 1.10   Separability Clause.  In case any provision in this
                         -------------------
Indenture or in the Debentures shall be invalid, illegal or unenforceable, the
validity, legality and enforceability of the remaining provisions shall not in
any way be affected or impaired thereby.

          Section 1.11   Benefits of Indenture. [The Company's obligations under
                         ---------------------
this Indenture and the Debentures will also be for the benefit of the holders
from time to time of the Preferred Securities.] Nothing in this Indenture or in
the Debentures, express or implied, shall give to any Person, other than the
parties thereto, any Paying Agent and their successors and assigns, [the holders
of the Preferred Securities] and the Holders of the Debentures, any benefit or
any legal or equitable right, remedy or claim under this Indenture.

                                      20
<PAGE>

          Section 1.12   Governing Law.  This Indenture and the Debentures shall
                         -------------
be governed by and construed in accordance with the laws of the State of New
York without regard to its principles of conflicts of laws.

          Section 1.13   Non-Business Days.  In any case where any Interest
                         -----------------
Payment Date, Redemption Date, or Stated Maturity of any Debenture shall not be
a Business Day, then (notwithstanding any other provision of this Indenture or
the Debentures) payment of interest or principal payable on such date will be
made on the next succeeding day that is a Business Day (and without any interest
or other payment in respect of any such delay) with the same force and effect as
if made on the Interest Payment Date or Redemption Date or at the Stated
Maturity.


                                  ARTICLE II

                                DEBENTURE FORM

          Section 2.1    Forms Generally.  The Debentures and the Trustee's
                         ---------------
certificate of authentication shall be in substantially the forms set forth in
this Article 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 applicable tax laws or the rules of any securities exchange or as may,
consistently herewith, be determined by the officers executing such Debentures,
as evidenced by their execution of the Debentures.

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

                                      21
<PAGE>

          Section 2.2    Form of Face of Debenture.
                         -------------------------

          __% [Convertible] Subordinated Debenture due __________, 20__.
No.                                  $

          Alcoa Inc., a corporation organized and existing under the laws of
Pennsylvania (hereinafter called the "Company", which term includes any
successor corporation under the Indenture hereinafter referred to), for value
received, hereby promises to pay to ______________________, or registered
assigns, the principal sum of ______________________________________ on ______,
20__ and to pay interest on said principal sum from __________, 20__ or from the
most recent interest payment date (each such date, an "Interest Payment Date")
to which interest has been paid or duly provided for, at the rate of _% per
annum, subject to deferral as set forth herein, on __________, ________, _______
and __________ of each year, commencing __________, 20__ until the principal
hereof is paid or duly provided for or made available for payment.

          Reference is hereby made to the further provisions of this Debenture
set forth on the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

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

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

Dated:

                                        ALCOA INC.

                                        BY:________________________________

ATTEST

____________________________
Name:
Title:

                                      22
<PAGE>

          Section 2.3    Form of Reverse of Debenture.  This Debenture is one of
                         ----------------------------
a duly authorized issue of Debentures of the Company (herein called the
"Debentures") limited to the aggregate principal amount of $______________,
issued under an Indenture, dated as of _____ __, 20__ (herein called the
"Indenture"), between the Company and Chase Manhattan Trust Company, National
Association, as Trustee (herein called the "Trustee", which term includes any
successor trustee under the Indenture), to which Indenture and all indentures
supplemental thereto reference is hereby made for a statement of the respective
rights, limitations of rights, duties and immunities thereunder of the Trustee,
the Company and the Holders of the Debentures, and of the terms upon which the
Debentures are, and are to be, authenticated and delivered. All terms used in
this Debenture that are defined in the Indenture shall have the meanings
assigned to them in the Indenture.

          The amount of interest payable for any period will be computed on the
basis of a 360-day year of twelve 30-day months.  For periods less than a full
month, interest shall be computed on the actual number of elapsed days based on
a 360-day year.  In the event that any date on which interest is payable on this
Debenture is not a Business Day, then a payment of the interest on such date
will be made on the next succeeding day which is a Business Day (and without any
interest or other payment in respect of any such delay) with the same force and
effect as if made on the date the payment was originally payable.  A "Business
Day" shall mean any day other than a Saturday or a Sunday or a day on which
banking institutions in the

                                      23
<PAGE>

City of New York are authorized or required by law or executive order to remain
closed or a day on which the Corporate Trust Office of the Trustee[, or the
principal office of the Property Trustee under the Trust Agreement] is closed
for business. The interest installment so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in the Indenture,
be paid to the Person in whose name this Debenture (or one or more Predecessor
Debentures, as defined in the Indenture) is registered at the close of business
on the Regular Record Date, for such interest installment which shall be the
date which is the fifteenth day (whether or not a Business Day) next preceding
such Interest Payment Date. Any such interest installment not so punctually paid
or duly provided for shall forthwith cease to be payable to the Holder on such
Regular Record Date and may either be paid to the Person in whose name this
Debenture (or one or more Predecessor Debentures) is registered at the close of
business on a Special Record Date for the payment of such Defaulted Interest to
be fixed by the Trustee, notice whereof shall be given to Holders of Debentures
not less than 10 days prior to such Special Record Date, or be paid at any time
in any other lawful manner not inconsistent with the requirements of any
securities exchange on which the Debentures may be listed, and upon such notice
as may be required by such exchange, all as more fully provided in the
Indenture.

          The Company shall have the right at any time during the term of this
Debenture, from time to time, to extend the interest payment period of such
Debenture for up to [20 consecutive quarters] with respect to each deferral
period (each such deferral period an "Extension Period"), during which periods
the Company shall have the right not to make payments of interest on any
Interest Payment Date, and at the end of which the Company shall pay all
interest then accrued and unpaid (together with Additional Interest, if any,
thereon to the extent permitted by applicable law); provided that during any
such Extension Period, the Company shall not (a) declare or pay any dividend on,
make distributions with respect to, or redeem, purchase or make a liquidation
payment with respect to, any of its Common Stock (other than (i) purchases or
acquisitions of shares of Common Stock in connection with the satisfaction by
the Company of its obligations under any employee benefit plan, (ii) as a result
of a reclassification of the Company's Common Stock or the exchange or
conversion of one class or series of the Company's Common Stock for another
class or series of the Company's Common Stock, (iii) the purchase of fractional
interests in shares of the Company's Common Stock pursuant to the conversion or
exchange provisions of such Common Stock of the Company or the security being
converted or exchanged or (iv) purchases or acquisitions of shares of Common
Stock to be used in connection with acquisitions of Common Stock by

                                      24
<PAGE>

shareholders pursuant to the Company's dividend reinvestment plan) or make any
guarantee payments with respect to the foregoing and (b) the Company shall not
make any payment of principal or premium, if any, on or repurchase any debt
securities (including guarantees) other than at stated maturity issued by the
Company which rank pari passu with or junior to the Debentures. Prior to the
termination of any such Extension Period, the Company may further extend the
interest payment period, provided that no Extension Period shall exceed [20
consecutive quarters] or extend beyond the Stated Maturity of the Debenture.
Upon the termination of any such Extension Period and upon the payment of all
accrued and unpaid interest and any Additional Interest then due, the Company
may elect to begin a new Extension Period, subject to the above requirements. No
interest shall be due and payable during an Extension Period except at the end
thereof. The Company shall give the Trustee, [the Property Trustee and the
Administrative Trustees (as defined in the Trust Agreement)] notice of its
selection of an Extension Period at least one Business Day prior to [the earlier
of (i) the record date for the date the distributions on the Preferred
Securities (or if no Preferred Securities are outstanding, for] the date
interest on the Debentures) would have been payable except for the election to
begin such Extension Period and (ii) the date [the Property Trustee (or if no
Preferred Securities are outstanding,] the Debenture Trustee) is required to
give notice to the NYSE or other applicable self-regulatory organizations [or to
holders of [such Preferred Securities (or, if no Preferred Securities are
outstanding, to the holders of] such Debentures) of the record date.

          Payment of the principal of (and premium, if any) and interest on this
Debenture will be made [if a Global Security is issued - to The Depository
Trust Company or its nominee] [if securities in definitive form are issued - at
the office or agency of the Paying Agent maintained for that purpose in the
United States], in such coin or currency of the United States of America as at
the time of payment is legal tender for payment of public and private debts
provided, however, that at the option of the Company payment of interest may be
made (i) by check mailed to the address of the Person entitled thereto as such
address shall appear in the Securities Register or (ii) by wire transfer in
immediately available funds at such place and to such account as may be
designated by the Person entitled thereto as specified in the Securities
Register.

          The indebtedness evidenced by this Debenture is, to the extent
provided in the Indenture, subordinate and subject in right of payments to the
prior payment in full of all Senior Debt (as defined in the Indenture), and this
Debenture is issued subject to the provisions of the Indenture with respect
thereto.  Each Holder of this Debenture, by accepting the same, (a) agrees to
and shall be bound by such provisions, (b) authorizes and directs the Trustee on
his behalf to take such actions as

                                      25
<PAGE>

may be necessary or appropriate to effectuate the subordination so provided and
(c) appoints the Trustee his attorney-in-fact for any and all such purposes.
Each Holder hereof, by his acceptance hereof, waives all notice of the
acceptance of the subordination provisions contained herein and in the Indenture
by each holder of Senior Debt, whether now outstanding or hereafter incurred,
and waives reliance by each such holder upon said provisions.

          At any time on or after _________, 20__, the Company may, at its
option, subject to the terms and conditions of Article 11 of the Indenture,
redeem this Debenture in whole at any time or in part from time to time, at the
Redemption Prices set forth in Section 11.8 of the Indenture.

          In the event of redemption of this Debenture in part only, a new
Debenture or Debentures for the unredeemed portion hereof will be issued in the
name of the Holder hereof upon the cancellation hereof.

          [If a Special Event shall occur and be continuing, this Debenture
shall be exchangeable for Preferred Securities in accordance with Section 11.9
of the Indenture or, in certain circumstances, redeemable by the Company in
accordance with Section 11.8 of the Indenture.]

         [Subject to the terms and conditions set forth in Article 13 of the
Indenture, this Debenture is convertible, at the option of the Holder hereof,
into shares of Common Stock.]

          If an Event of Default shall occur and be continuing, the principal of
the Debentures may be declared due and payable in the manner, with the effect
and subject to the conditions provided in the Indenture.

          The Indenture contains provisions for satisfaction, discharge and
defeasance of the entire indebtedness of this Debenture upon compliance by the
Company with certain conditions set forth in the Indenture.

          The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Debentures to be affected under the
Indenture at any time by the Company and the Trustee with the consent of the
Holders of a majority in principal amount of the Debentures.  The Indenture also
contains provisions permitting Holders of specified percentages in principal
amount

                                      26
<PAGE>

of the Debentures at the time Outstanding, on behalf of the Holders of all
Debentures, to waive compliance by the Company with certain provisions of the
Indenture and certain past defaults under the Indenture and their consequences.
Any such consent or waiver shall be conclusive and binding upon the Holder of
this Debenture and upon all future Holders of this Debenture and of any
Debenture issued upon the registration of transfer hereof or in exchange
therefor or in lieu hereof, whether or not notation of such consent or waiver is
made upon this Debenture.

          As provided in and subject to the provisions of the Indenture, if an
Event of Default occurs and is continuing, then and in every such case the
Trustee or the Holders of not less than 25% in principal amount of the
Outstanding Debentures may declare the principal amount of all the Debentures to
be due and payable immediately, by a notice in writing to the Company (and to
the Trustee if given by Holders); [provided that, if upon an Event of Default,
the Trustee or the Holders of not less than 25% in principal amount of the
Outstanding Debentures fail to declare the principal of all the Debentures to be
immediately due and payable, the holders of at least 25% in aggregate
liquidation amount of the Preferred Securities then out standing shall have such
right by a notice in writing to the Company and the Trustee,] and upon any such
declaration such principal amount (or specified amount) of and the accrued
interest (including any Additional Interest) on all the Debentures shall become
immediately due and payable, provided that the payment of principal and interest
(including any Additional Interest) on such Debentures shall remain subordinated
to the extent provided in Article 12 of the Indenture.

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

          As provided in the Indenture and subject to certain limitations
therein set forth, the transfer of this Debenture is registrable in the
Securities Register, upon surrender of this Debenture for registration of
transfer at the Company Office duly endorsed by, or accompanied by a written
instrument of transfer in form satisfactory to the Company and the Securities
Registrar duly executed by, the Holder hereof or his attorney duly authorized in
writing, and thereupon one or more new Debentures, of authorized denominations
and for the same aggregate principal amount, will be issued to the designated
transferee or transferees.  No service charge shall be made for any such
registration of transfer or exchange, but the Company may require

                                      27
<PAGE>

payment of a sum sufficient to cover any tax or other governmental charge
payable in connection therewith.

          Prior to due presentment of this Debenture for registration of
transfer, the Company, the Trustee and any agent of the Company or the Trustee
may treat the Person in whose name this Debenture is registered as the owner
hereof for all purposes, whether or not this Debenture be overdue, and neither
the Company, the Trustee nor any such agent shall be affected by notice to the
contrary.

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

          The Company and, by its acceptance of this Debenture or a beneficial
interest therein, the Holder of, and any Person that acquires a beneficial
interest in, this Debenture agree that for United States Federal, state and
local tax purposes it is intended that this Debenture constitute indebtedness.

          THE INDENTURE AND THIS DEBENTURE SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO CONFLICTS OF
LAW PRINCIPLES THEREOF.

                                      28
<PAGE>

                                ASSIGNMENT FORM

               To assign this Debenture, fill in the form below:

               (I) or (we) assign and transfer this Security to______________

_____________________________________________________________________________
              (Insert assignee's social security or tax I.D. no.)

_____________________________________________________________________________

_____________________________________________________________________________

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

and irrevocably appoint______________________________________________________
agent to transfer this Debenture on the books of the Company.  The agent may
substitute another to act for him.


                        Your Signature:______________________________________
                                       (Sign exactly as your name appears on
                                       the other side of this Security)

Date:___________________


                        Signature Guarantee:/1/______________________________



_______________________

/1/  Signature must be guaranteed by an institution which is a member of one of
     the following recognized Signature Guaranty Programs: (i) The Securities
     Transfer Agent Medallion Program (STAMP); (ii) The New York Stock Exchange
     Medallion Program (MSP); (iii) The Stock Exchange Medallion Program (SEMP);
     or (iv) in such other guarantee programs acceptable to the Trustee.

                                      29
<PAGE>

                            [NOTICE OF CONVERSION

To:  Alcoa Inc.
     201 Isabella Street
     Pittsburgh, Pennsylvania 15212-5858

          The undersigned owner of this Debenture hereby irrevocably exercises
the option to convert this Debenture, or the portion below designated, into
Common Stock of Alcoa Inc. in accordance with the terms of the Indenture
referred to in this Debenture, and directs that the shares issuable and
deliverable upon conversion, together with any check in payment for fractional
shares, be issued in the name of and delivered to the undersigned, unless a
different name has been indicated in the assignment below. If shares are to be
issued in the name of a person other than the undersigned, the undersigned will
pay all transfer taxes payable with respect thereto.


Date: ____________, ____

       in whole  __
                             Portions of Debenture to be converted
       in part   __          ($50 or integral multiples thereof):
                             $_________________

                           ____________________________________________
                           Signature (for conversion only)

                             Please Print or Typewrite Name and Address,
                             Including Zip Code, and Social Security or
                             Other Identifying Number


     Signature Guarantee:/1/___________________________________________]

______________________

/1/  Signature must be guaranteed by an institution which is a member of one of
     the following recognized Signature Guaranty Programs: (i) The Securities
                                                                  (continued...)

                                      30
<PAGE>

          Section 2.4  Additional Provisions Required in Global Security.  Any
                       -------------------------------------------------
Global Security issued hereunder shall, in addition to the provisions contained
in Sections 2.2 and 2.3 bear a legend in substantially the following form:

     "This Debenture 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 of a Depositary. This Debenture is
     exchangeable for Debentures registered in the name of a person
     other than the Depositary or its nominee only in the limited
     circumstances described in the Indenture and may not be
     transferred except as a whole by the Depositary to a nominee of
     the Depositary or by a nominee of the Depositary to the
     Depositary or another nominee of the Depositary."

          Section 2.5  Form of Trustee's Certificate of Authentication.  The
                       -----------------------------------------------
form of Trustee's Certificate of Authentication shall be as follows:/1/

     "This is one of the Debentures designated therein referred to in the within
     mentioned Indenture.

     Chase Manhattan Trust Company, National Association
     as Trustee

     By:_______________________
     Authorized Officer

______________________

(...continued)
     Transfer Agent Medallion Program (STAMP); (ii) The New York Stock Exchange
     Medallion Program (MSP); (iii) The Stock Exchange Medallion Program (SEMP);
     or (iv) in such other guarantee programs acceptable to the Trustee.

/1/  Or in the form provided in Section 6.14 in the event that a separate
     Authenticating Agent is appointed pursuant thereto.

                                      31
<PAGE>

          [Section 2.6  Initial Issuance to Property Trustee.  The Debentures
                        ------------------------------------
initially issued to the Property Trustee of the Trust shall be in the form of
one or more individual certificates in definitive, fully registered form without
coupons.]

                                  ARTICLE III

                                THE DEBENTURES

          Section 3.1  Amount of Debentures.  The aggregate principal amount of
                       --------------------
Debentures which may be authenticated and delivered under this Indenture is
limited to the sum of (a) $______________ [and (b) such aggregate principal
amount (which may not exceed $________ aggregate principal amount) of
Debentures, if any, issued as a result of the exercise of the over-allotment
option] described in the Underwriting Agreement, dated ________, 20__, among the
Company[, the Trust] and the underwriters named therein, and the Related Pricing
Agreement, except for Debentures authenticated and delivered upon registration
of, transfer of, or in exchange for, or in lieu of other Debentures pursuant to
Sections 3.4, 3.5 or 3.6.

          Section 3.2  Denominations.  The Debentures shall be in registered
                       -------------
form without coupons and shall be issuable in denominations of [$1,000] and any
integral multiple thereof.

          Section 3.3  Execution, Authentication, Delivery and Dating.  The
                       ----------------------------------------------
Debentures shall be executed on behalf of the Company by a duly authorized
officer on behalf of the Company, whose signature shall be certified by the
Company's Secretary or one of its Assistant Secretaries.  The signature of any
of these officers on the Debentures may be manual or facsimile.

          Debentures 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 Debentures or did not
hold such offices at the date of such Debentures.  Upon the execution and
delivery of this Indenture, or from time to time thereafter, Debentures may be
executed by the Company and delivered to the Trustee for authentication, and the
Trustee shall thereupon authenticate and make available for delivery said
Debentures upon Company Order without any further action by the Company.
Debentures may be

                                      32
<PAGE>

authenticated on original issuance from time to time and delivered pursuant to
such procedures acceptable to the Trustee ("Procedures") as may be specified
from time to time by Company Order. Procedures may authorize authentication and
delivery pursuant to oral instructions of the Company or a duly authorized
agent, which instructions shall be promptly confirmed in writing.

          Each Debenture shall be dated the date of its authentication.

          No Debenture shall be entitled to any benefit under this Indenture or
be valid or obligatory for any purpose, unless there appears on such Debenture a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by the manual signature of one of its authorized
officers, and such certificate upon any Debenture shall be conclusive evidence,
and the only evidence, that such Debenture has been duly authenticated and
delivered hereunder.

          Section 3.4  Temporary Debentures.  Pending the preparation of
                       --------------------
definitive Debentures, the Company may execute, and upon Company Order the
Trustee shall authenticate and deliver, temporary Debentures which are printed,
lithographed, typewritten, mimeographed or otherwise produced, in any authorized
denomination, substantially of the tenor of the definitive Debentures in lieu
of which they are issued and with such appropriate insertions, omissions,
substitutions and other variations as the officers executing such Debentures may
determine, as evidenced by their execution of such Debentures.

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

          Section 3.5  Registration, Transfer and Exchange.  The Company shall
                       -----------------------------------
cause to be kept at the Corporate Trust Office of the Trustee a register in
which, subject to such reasonable regulations as it may prescribe, the Company
shall provide for the registration of Debentures and of transfers of Debentures.
Such register is

                                      33
<PAGE>

herein sometimes referred to as the "Securities Register." The Trustee is hereby
appointed "Securities Registrar" for the purpose of registering Debentures and
transfers of Debentures as herein provided.

          Upon surrender for registration of transfer of any Debenture at the
office or agency of the Company designated for that purpose the Company shall
execute, and the Trustee shall authenticate and deliver, in the name of the
designated transferee or transferees, one or more new Debentures of any
authorized denominations, of a like aggregate principal amount.

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

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

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

          No service charge shall be made to a Holder for any transfer or
exchange of Debentures, 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 transfer or exchange of Debentures.

          Notwithstanding any of the foregoing, any Global Security shall be
exchangeable pursuant to this Section 3.5 for Debentures registered in the names
of Persons other than the Depositary for such Debenture or its nominee only if
(a) such Depositary notifies the Company that it is unwilling or unable to
continue as Depositary for any Global Security and the Company shall not have
appointed a successor depositary within 90 days after such notice, or if at any
time such Depositary ceases

                                      34
<PAGE>

to be a clearing agency registered under the Securities Exchange Act of 1934, as
amended, (b) the Company executes and delivers to the Trustee a Company Order
that any Global Security shall be so exchangeable or (c) there shall have
occurred and be continuing an Event of Default. Any Global Security shall be
exchangeable for Debentures registered in such names as such Depositary shall
direct.

          Notwithstanding any other provisions in this Indenture, a Global
Security may not be transferred except as a whole by the Depositary with respect
to a Global Security to a nominee of such Depositary or by a nominee of such
Depositary to such Depositary or another nominee of such Depositary.

          Neither the Company nor the Trustee shall be required, pursuant to the
provisions of this Section, (a) to issue, register the transfer of or exchange
any Debenture during a period beginning at the opening of business 15 days
before the day of selection for redemption of Debentures pursuant to Article 11
and ending at the close of business on the day of mailing of notice of
redemption or (b) to register the transfer of or exchange any Debenture so
selected for redemption in whole or in part, except, in the case of any
Debenture to be redeemed in part, any portion thereof not to be redeemed.

          Section 3.6  Mutilated, Destroyed, Lost and Stolen Debentures.  If any
                       ------------------------------------------------
mutilated Debenture is surrendered to the Trustee together with such security or
indemnity as may be required by the Company or the Trustee to save each of them
harmless, the Company shall execute and the Trustee shall authenticate and
deliver in exchange therefor a new Debenture and bearing a number not
contemporaneously outstanding.

          If there shall be delivered to the Company and to the Trustee (a)
evidence to their satisfaction of the destruction, loss or theft of any
Debenture, and (b) such security or indemnity as may be required by them to save
each of them harmless, then, in the absence of actual notice to the Company or
the Trustee that such Debenture has been acquired by a bona fide purchaser, the
Company shall execute and upon a Company Order the Trustee shall authenticate
and deliver, in lieu of any such destroyed, lost or stolen Debenture, a new
Debenture bearing a number not contemporaneously outstanding.

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

                                      35
<PAGE>

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

          Every new Debenture issued pursuant to this Section in lieu of any
destroyed, lost or stolen Debenture shall constitute an original additional
contractual obligation of the Company, whether or not the destroyed, lost or
stolen Debenture 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 Debentures 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 Debentures.

          Section 3.7  Payment of Interest; Interest Rights Preserved.  Interest
                       ----------------------------------------------
on any Debenture 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
Debenture (or one or more Predecessor Debentures) is registered at the close of
business on the Regular Record Date, except that interest payable on the Stated
Maturity of the Debentures shall be paid to the Person to whom principal is
paid.

          Any interest on the Debentures which is payable, but is not timely
paid or duly provided for, on an Interest Payment Date (herein called "Defaulted
Interest"), shall forthwith cease to be payable to the registered Holder on the
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 (a) or (b) below:

                (a) The Company may elect to make payment of any Defaulted
Interest to the Persons in whose names the Debentures (or their respective
Predecessor Debentures) 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 the Debentures 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

                                      36
<PAGE>

such deposit prior to the date of the proposed payment, such money when
deposited to be held in trust for the benefit of the Persons entitled to such
Defaulted Interest as in this Clause provided. Thereupon the Trustee shall fix a
Special Record Date for the payment of such Defaulted Interest which shall be
not more than 15 days and not less than 10 days prior to the date of the
proposed payment and not less than 10 days after the receipt by the Trustee of
the notice of the proposed payment. The Trustee shall promptly notify the
Company of such Special Record Date and, in the name and at the expense of the
Company, shall cause notice of the proposed payment of such Defaulted Interest
and the Special Record Date therefor to be mailed, first class, postage prepaid,
to each Holder of the Debentures at the address of such Holder as it appears in
the Securities Register not less than 10 days prior to such Special Record Date.
Notice of the proposed payment of such Defaulted Interest and the Special Record
Date therefor having been mailed as aforesaid, such Defaulted Interest shall be
paid to the Persons in whose names the Debentures (or their respective
Predecessor Debentures) are registered on such Special Record Date and shall no
longer be payable pursuant to the following clause (b).

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

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

          Section 3.8  Persons Deemed Owners.  The Company, the Trustee, the
                       ---------------------
Paying Agent and any agent of the Company or the Trustee or the Paying Agent may
treat the Person in whose name any Debenture is registered as the owner of such
Debenture for the purpose of receiving payment of principal of and (subject to
Section 3.7) interest on such Debenture and for all other purposes whatsoever,
whether or not such Debenture be overdue, and neither the Company, the Trustee
nor any agent of the Company or the Trustee shall be affected by notice to the
contrary.

          Section 3.9  Cancellation.  All Debentures surrendered for payment,
                       ------------
redemption, conversion, registration of transfer or exchange shall, if
surrendered to any Person other

                                      37
<PAGE>

than the Trustee, be delivered to the Trustee, and any such Debentures and
Debentures surrendered directly to the Trustee for any such purpose shall be
promptly canceled by it. The Company may at any time deliver or cause to be
delivered to the Trustee for cancellation any Debentures previously
authenticated and delivered hereunder which the Company may have acquired in any
manner whatsoever, and all Debentures so delivered shall be promptly canceled by
the Trustee. No Debentures shall be authenticated in lieu of or in exchange for
any Debentures canceled as provided in this Section, except as expressly
permitted by this Indenture. All canceled Debentures shall be destroyed by the
Trustee and upon request, the Trustee shall deliver to the Company a certificate
of such destruction.

          Section 3.10  Computation of Interest.  Interest on the Debentures
                        -----------------------
shall be computed on the basis of a 360-day year of twelve 30-day months.

          Section 3.11  Deferrals of Interest Payment Dates.  The Company shall
                        -----------------------------------
have the right, at any time during the term of the Debentures, from time to time
to extend the interest payment period for the Debentures for up to [20
consecutive quarters] with respect to each deferral period (each, an "Extension
Period") during which periods the Company shall have the right to not make
payments of interest on any Interest Payment Date, and at the end of such
Extension Period the Company shall pay all interest then accrued and unpaid
thereon (together with Additional Interest thereon, if any, at the rate
specified for the Debentures to the extent permitted by applicable law),
provided, however, that during any such Extension Period, the Company shall not
(a) declare or pay any dividend on, make distributions with respect to, or
redeem, purchase or make a liquidation payment with respect to, any of its
Common Stock (other than (i) purchases or acquisitions of shares of Common Stock
in connection with the satisfaction by the Company of its obligations under any
employee benefit plan, (ii) as a result of a reclassification of the Company's
Common Stock or the exchange or conversion of one class or series of the
Company's Common Stock for another class or series of the Company's Common
Stock, (iii) the purchase of fractional interests in shares of the Company's
Common Stock pursuant to the conversion or exchange provisions of such Common
Stock of the Company or the security being converted or exchanged or (iv)
purchases or acquisitions of shares of Common Stock to be used in connection
with acquisitions of Common Stock by shareholders pursuant to the Company's
dividend reinvestment plan) or make any guarantee payments with respect to the
foregoing and (b) the Company shall not make any payment of principal or
premium, if any, on or repurchase any debt securities (including guarantees)
other than at stated maturity issued by the Company which rank pari passu with

                                      38
<PAGE>

or junior to the Debentures. Prior to the termination of any such Extension
Period, the Company may further extend the interest payment period, provided
that no Extension Period shall exceed [20 consecutive quarters] or extend beyond
the Stated Maturity of the Debentures. Upon the termination of any such
Extension Period and upon the payment of all accrued and unpaid interest and any
Additional Interest then due, the Company may elect to begin a new Extension
Period, subject to the above requirements. No interest shall be due and payable
during an Extension Period except at the end thereof. The Company shall give the
Trustee[, the Property Trustee and the Administrative Trustees (as defined in
the Trust Agreement)] notice of its selection of an Extension Period at least
one Business Day prior to the earlier of (i) the record date for the date [the
distributions on the Preferred Securities (or if no Preferred Securities are
outstanding, for the date] interest on the Debentures[)] would have been payable
except for the election to begin such Extension Period and (ii) the date the
[Property Trustee (or if no Preferred Securities are outstanding, the Debenture]
Trustee[)] is required to give notice to the NYSE or other applicable self-
regulatory organizations or[ to holders of such Preferred Securities (or, if no
Preferred Securities are outstanding,] to the holders of such Debentures[)] of
the record date. Such notice shall specify the period selected.

          The Company, or the Trustee at the request of the Company, shall
promptly give notice of the Company's selection of such Extension Period to the
Holders of the outstanding Debentures.

          Section 3.12  Right of Set-off.  Notwithstanding anything to the
                        ----------------
contrary in the Indenture, the Company shall have the right to set-off any
payment it is otherwise required to make thereunder in respect of the Debentures
to the extent the Company has theretofore made, or is concurrently on the date
of such payment making, a payment relating to the Debentures under the
Guarantee.

          Section 3.13  Agreed Tax Treatment.  Each Debenture issued hereunder
                        --------------------
shall provide that the Company and, by its acceptance of a Debenture or a
beneficial interest therein, the Holder of, and any Person that acquires a
beneficial interest in, such Debenture agree that for United States Federal,
state and local tax purposes it is intended that such Debenture constitute
indebtedness.

          Section 3.14  CUSIP Numbers.  The Company in issuing the Debentures
                        -------------
may use "CUSIP" numbers (if then generally in use), and, if so, the Trustee
shall use such "CUSIP" number in notices of redemption as a convenience to
Holders; provided that any such notice may state that no representation is made
as to the correctness of such number either as printed on the Debentures or as
contained in

                                      39
<PAGE>

any notice of a redemption and that reliance may be placed only on the other
identification numbers printed on the Debentures, and any such redemption shall
not be affected by any defect in or omission of such numbers.

          Section 3.15  Global Security.  [(a)  In connection with any
                        ---------------
distribution of Debentures to holders of the Preferred Securities in connection
with the involuntary or voluntary dissolution, winding up or liquidation of the
Trust,

                        (i)  the Debentures in certificated form may be
     presented to the Trustee by the Property Trustee in exchange for one or
     more global certificates in an aggregate principal amount equal to the
     aggregate principal amount of all outstanding Debentures (each a "Global
     Security"), to be registered in the name of the Depositary, or its nominee,
     and delivered by the Trustee to the Depositary, or its custodian, for
     crediting to the accounts of its participants pursuant to the procedures of
     the Depositary. The Company upon any such presentation shall execute a
     Global Security in such aggregate principal amount and deliver the same to
     the Trustee for authentication and delivery in accordance with this
     Indenture; and

                        (ii) if any Preferred Securities are held in non book-
     entry certificated form, the Debentures in certificated form may be
     presented to the Trustee by the Property Trustee and any Preferred Security
     certificate which represents Preferred Securities other than Preferred
     Securities held by the Depositary or its nominee ("Non Book-Entry Preferred
     Securities") will be deemed to represent beneficial interests in Debentures
     presented to the Trustee by the Property Trustee having an aggregate
     principal amount equal to the aggregate liquidation amount of the Non Book-
     Entry Preferred Securities until such Preferred Security certificates are
     presented to the Securities Registrar for registration of transfer or
     reissuance at which time such Non-Book Entry Preferred Security
     certificates will be canceled and a Debenture, registered in the name of
     the holder of the Preferred Security certificate or the transferee of the
     holder of such Preferred Security certificate, as the case may be, with an
     aggregate principal amount equal to the aggregate liquidation amount of the
     Preferred Security certificate canceled, will be executed by the Company
     and delivered to the Trustee for authentication and delivery in accordance
     with this Indenture. On issue of such Debentures, Debentures with an
     equivalent aggregate principal amount that were presented by the Property
     Trustee to the Trustee will be deemed to have been canceled.]

                                      40
<PAGE>

               (b) A Global Security may be transferred, in whole but not in
part, only to another nominee of the Depositary, or to a nominee of such
successor Depositary.

               (c) If (i) the Depositary notifies the Company that it is
unwilling or unable to continue as a depositary for such Global Security and no
successor depositary shall have been appointed within 90 days by the Company,
(ii) the Depositary, at any time, ceases to be a clearing agency registered
under the Exchange Act at which time the Depositary is required to be so
registered to act as such depositary and no successor depositary shall have been
appointed within 90 days by the Company, (iii) the Company, in its sole
discretion, determines that such Global Security shall be so exchangeable or
(iv) there shall have occurred an Event of Default with respect to such
Debentures, as the case may be, the Company will execute, and, subject to
Article 3 of this Indenture, the Trustee, upon written notice from the Company
and receipt of a Company Order, will authenticate and deliver the Debentures in
definitive registered form without coupons, in authorized denominations, and in
an aggregate principal amount equal to the principal amount of the Global
Security in exchange for such Global Security. In addition, upon an Event of
Default or if the Company may at any time determine that the Debenture shall no
longer be represented by a Global Security, in such event the Company will
execute, and subject to Section 3.5 of this Indenture, the Trustee, upon receipt
of an Officers' Certificate evidencing such determination by the Company and a
Company Order, will authenticate and make available for delivery the Debentures
in definitive registered form without coupons, in authorized denominations, and
in an aggregate principal amount equal to the principal amount of the Global
Security in exchange for such Global Security. Upon the exchange of the Global
Security for such Debentures in definitive registered form without coupons, in
authorized denominations, the Global Security shall be canceled by the Trustee.
Such Debentures in definitive registered form issued in exchange for the Global
Security shall be registered in such names and in such authorized denominations
as the Depositary, pursuant to instructions from its direct or indirect
participants or otherwise, shall instruct the Trustee. The Trustee shall deliver
such Debentures to the Depositary for delivery to the Persons in whose names
such Debentures are so registered.

                                      41
<PAGE>

                                  ARTICLE IV

                   SATISFACTION AND DISCHARGE OF INDENTURE;
                               UNCLAIMED MONEYS

          Section 4.1  Satisfaction and Discharge of Indenture.  (A) If at any
                       ---------------------------------------
time (a) the Company shall have paid or caused to be paid the principal of, and
interest, if any, on, all the Debentures theretofore authenticated (other than
Debentures which have been destroyed, lost or stolen and which have been
replaced or paid as provided in Section 3.6), in accordance with the terms of
this Indenture and such Debentures or (b) as to Debentures not so paid, the
Company shall have delivered to the Trustee for cancellation all Debentures
theretofore authenticated (other than any Debentures which shall have been
destroyed, lost or stolen and which shall have been replaced or paid as provided
in Section 3.6) or (c) as to Debentures not so paid or delivered for
cancellation, (i) all the Debentures shall have become due and payable, or are
by their terms to become due and payable within one year or are to be called for
redemption within one year under arrangements satisfactory to the Trustee for
the giving of notice of redemption, and (ii) the Company shall have irrevocably
deposited or caused to be deposited with the Trustee as trust funds money in an
amount (other than moneys repaid by the Trustee or any paying agent to the
Company in accordance with Section 4.4) or Government Obligations, maturing as
to principal and interest at such times and in such amounts as will ensure the
availability of money, or a combination thereof, 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 (A) the principal
and interest, if any, on all Debentures on each date that such principal or
interest, if any, is due and payable and (B) any mandatory sinking fund or
analogous payments on the dates on which such payments are due and payable in
accordance with the terms of this Indenture and the Debentures; and if, in any
such case, the Company shall also pay or cause to be paid all other sums payable
hereunder by the Company then this Indenture shall cease to be of further effect
(except as to (i) rights of registration of transfer and exchange of Debentures
and the Company's right of optional redemption, if any, (ii) substitution of
mutilated, defaced, destroyed, lost or stolen Debentures, (iii) the rights of
Holders to receive Debentures, payments of principal thereof, and interest, if
any, thereon, upon the original stated due dates therefor or any date of
redemption (but not upon acceleration), and remaining rights of such Holders to
receive mandatory sinking fund or analogous payments, if any, (iv) the rights,
obligations, duties and immunities of the Trustee hereunder, (v) the rights of
Holders as beneficiaries

                                      42
<PAGE>

hereof with respect to the property so deposited with the Trustee and payable to
all or any of them, (vi) conversion of the Debentures under Article 13, [(vii)
maintenance of the Trust for United States Federal income tax purposes as a
grantor trust under Section 10.8] and (viii) the maintenance of the Company
Office and the Trustee, on demand of the Company accompanied by an Officers'
Certificate and an Opinion of Counsel, each stating that all conditions
precedent herein provided for relating to the satisfaction and discharge of this
Indenture have been complied with, and at the cost and expense of the Company,
shall execute proper instruments acknowledging such satisfaction and discharge
of this Indenture. The Company agrees to reimburse the Trustee for any costs or
expenses thereafter reasonably and properly incurred and to compensate the
Trustee for any services thereafter reasonably and properly rendered by the
Trustee in connection with this Indenture or the Debentures.

          (B)  In addition to discharge of this Indenture pursuant to the next
preceding paragraph (A) the Company shall be deemed to have paid and discharged
the entire indebtedness on all the Debentures on the 123rd day after the date of
making the deposit referred to in clause (a), and the provisions of this
Indenture with respect to the Debentures shall no longer be in effect (except as
to (i) rights of registration of transfer and exchange of Debentures and the
Company's right of optional redemption, if any, (ii) substitution of mutilated,
defaced, destroyed, lost or stolen Debentures, (iii) the rights of Holders of
Debentures to receive payments of principal thereof and interest, if any,
thereon upon the original stated due dates therefor or any date of redemption
(but not upon acceleration), and remaining rights of such Holders to receive
mandatory sinking fund or analogous payments, if any, solely from the trust fund
referred to in subparagraph (a) below, (iv) the rights, obligations, duties and
immunities of the Trustee hereunder, (v) the rights of Holders as beneficiaries
hereof with respect to the property so deposited with the Trustee and payable to
all or any of them, [(vi) conversion of the Debentures under Article 13,] [(vii)
maintenance of the Trust for United States Federal income tax purposes as a
grantor trust under Section 10.8, (viii) the payment of any Additional Sums due
under Section 10.7, (ix) the payment of Trust expenses under Section 10.09,] and
(x) the maintenance of the Company Office and the Trustee, at the cost and
expense of the Company, shall, at the Company's written request, execute proper
instruments acknowledging the same, if:

               (a) the Company shall have irrevocably deposited or caused to be
irrevocably deposited with the Trustee as a trust fund specifically pledged as
security for, and dedicated solely to, the benefit of the Holders of the
Debentures (i) money in an amount, or (ii) Government Obligations, maturing as
to principal and interest at such times and in such amounts as will ensure the
availability of money, or

                                      43
<PAGE>

(iii) a combination thereof, sufficient in the opinion of a nationally
recognized firm of independent public accountants expressed in a written
certification therefor delivered to the Trustee, to pay (A) the principal and
interest, if any, on all Debentures on each date that such principal or
interest, if any, is due and payable and (B) any mandatory sinking fund or
analogous payments on the dates on which such payments are due and payable in
accordance with the terms of this Indenture and the Debentures;

               (b) no Event of Default or event which, with notice or lapse of
time or both, would become an Event of Default with respect to the Debentures
shall have occurred and be continuing on the date of such deposit or at any time
during the period ending on the 123rd day after the date of such deposit (it
being understood that this condition shall not be deemed satisfied until the
expiration of such period);

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

               (d) the Company shall have delivered to the Trustee an Opinion of
Counsel to the effect that (i) if such deposits shall include Government
Obligations in respect of any government other than the United States of
America, such deposit shall not result in the Company, the Trustee or such trust
constituting an 'investment company' under the Investment Company Act of 1940,
as amended, and (ii) if any such deposit occurs more than one year prior to the
stated maturity or redemption date of the Debentures, the Holders will not
recognize income, gain or loss for Federal income tax purposes as a result of
such deposit, defeasance and discharge and will be subject to Federal income tax
on the same amounts, in the same manner and at the same times as would have been
the case if such deposit, defeasance and discharge had not occurred; and

               (e) the Company shall have delivered to the Trustee an Officers'
Certificate and an Opinion of Counsel, each stating that all conditions
precedent herein provided for relating to the defeasance contemplated by this
paragraph have been complied with.

     (C) The Company shall be released from its obligations under Article Eight
and Article Ten [(except with respect to maintenance of the Trust as a grantor
trust for Federal Income Tax purposes under Section 10.8)] with respect to the
Debentures Outstanding on and after the date the conditions set forth below are
satisfied (hereinafter, 'covenant defeasance').  Covenant defeasance means that,
with respect to the Outstanding Debentures, the Company may omit to comply with
and shall have no liability in respect of any term, condition or limitation set
forth in Article Ten, whether directly or indirectly by reason of any reference
elsewhere herein to such Article by reason of any reference in such Article to
any other provi  sion herein or by reason of any reference to such Article in
any other document, and such omission to comply shall not constitute an Event of
Default under Section 5.1. The following shall be the conditions to application
of this paragraph (C):

               (a)  the Company shall have irrevocably deposited or caused to be
irrevocably deposited with the Trustee as a trust fund specifically pledged as
security for, and dedicated solely to, the benefit of the Holders of the
Debentures, (i) money in an amount, or (ii) Government Obligations, maturing as
to principal and interest at such times and in such amounts as will ensure the
availabil ity of money, or (iii) a combination thereof, sufficient in the
opinion of a nationally recognized firm of independent public accountants
expressed in a written certifica tion thereof delivered to the Trustee, to pay
(A) the principal and interest, if any, on all Debentures on each date that such
principal or interest, if any, is due and payable and (B) any mandatory sinking
fund or analogous payments on the dates on which such payments are due and
payable in accordance with the terms of this Indenture and the Debentures;

               (b)  no Event of Default or event which, with notice or lapse of
time or both, would become an Event of Default shall have occurred and be
continuing on the date of such deposit or at any time during the period ending
on the 123rd day after the date of such deposit (it being understood that this
condition shall not be deemed satisfied until the expiration of such period);

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

               (d)  the Company shall have delivered to the Trustee an Opinion
of Counsel to the effect that (i) if such deposits shall include Government
Obligations in respect of any government other than the United States of
America, such deposit shall not result in the Company, the Trustee or such trust
constituting an 'investment company' under the Investment Company Act of 1940,
as amended, and (ii) the Holders will not recognize income, gain or loss for
Federal income tax purposes as a result of such covenant defeasance and will be
subject to federal income tax on the same amounts, in the same manner and at the
same times as would have been the case if such covenant defeasance had not
occurred; and

               (e)  the Company shall have delivered to the Trustee an Officers'
Certificate and an Opinion of Counsel, each stating that all conditions
precedent herein provided for relating to such covenant defeasance have been
complied with.


          Section 4.2  Application by Trustee of Funds Deposited for Payment of
                       --------------------------------------------------------
Debentures.  Subject to Section 4.4, all moneys and Government Obligations
----------
deposited with the Trustee (or other trustee), and all money received by the
Trustee

                                      44
<PAGE>

in respect of Government Obligations deposited with the Trustee, pursuant to
Section 4.1 shall be held in trust and applied by it to the payment, either
directly or through any paying agent (including the Company acting as its own
paying agent), to the Holders of all sums due and to become due thereon for
principal and interest, if any; but such money need not be segregated from other
funds except to the extent required by law.

          Section 4.3  Repayment of Moneys Held by Paying Agent.  In connection
                       ----------------------------------------
with the satisfaction and discharge of this Indenture, all moneys then held by
any paying agent under the provisions of this Indenture shall, upon demand of
the Company, be repaid to it or paid to the Trustee and thereupon such paying
agent shall be released from all further liability with respect to such moneys.

          Section 4.4  Return of Moneys Held by Trustee and Paying Agent
                       -------------------------------------------------
Unclaimed for Three Years.  Any moneys deposited with or paid to the Trustee or
-------------------------
any paying agent for the payment of principal or interest, and not applied but
remaining unclaimed for three years after the date upon which such principal or
interest shall have become due and payable, shall, upon the written request of
the Company and unless otherwise required by mandatory provisions of applicable
escheat or abandoned or unclaimed property law, be repaid to the Company by the
Trustee or such paying agent, and any Holder shall, unless otherwise required by
mandatory provisions of applicable escheat or abandoned or unclaimed property
laws, thereafter look only to the Company for any payment which such Holder may
be entitled to collect, and all liability of the Trustee or any paying agent
with respect to such moneys shall thereupon cease; provided, however, that the
Trustee or such paying agent, before being required to make any such repayment
with respect to moneys deposited with it for any payment shall at the expense of
the Company, mail by first class mail to Holders of Debentures at their
addresses as they shall appear on the Securities Register for the Debentures,
notice that such moneys remain and that, after a date specified therein, which
shall not be less than 30 days from the date of such mailing any unclaimed
balance of such moneys then remaining will be repaid to the Company.

          Section 4.5  Indemnity for Government Obligations.  The Company shall
                       ------------------------------------
pay and indemnify the Trustee against any tax, fee or other charge imposed on or
assessed against the Government Obligations deposited pursuant to Section 4.1 or
the principal or interest received in respect of such Government Obligations,
other than any such tax, fee or other charge which by law is for the account of
the Holders for whose benefit such Government Obligations are held.

                                      45
<PAGE>

                                   ARTICLE V

                                   REMEDIES

          Section 5.1  Events of Default.  "Event of Default", wherever used
                       -----------------
herein with respect to the Debentures, 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):

               (a) default in the payment of any interest upon the Debenture,
including any Additional Interest in respect thereof, when it becomes due and
payable, and continuance of such default for a period of 30 days (subject to the
deferral of any due date in the case of an Extension Period); or

               (b) default in the payment of the principal of (or premium, if
any, on) the Debentures when due whether at Stated Maturity, upon redemption, by
declaration or otherwise; or

               (c) failure on the part of the Company duly to observe or perform
any other of the covenants or agreements on the part of the Company contained in
the Debentures or contained in this Indenture (other than a covenant or
agreement which has been expressly included in this Indenture solely for the
benefit of the Company) and continuance of such failure for a period of 90 days
after the date on which written notice of such failure, requiring the same to be
remedied and stating that such notice is a "Notice of Default" hereunder, shall
have been given by registered or certified mail to the Company by the Trustee,
or to the Company and the Trustee by a Holder or Holders of at least 25% in
aggregate principal amount of the Debentures at the time Outstanding or the
holder [or holders of at least 25% in aggregate liquidation amount of the
Preferred Securities];

               (d) failure by the Company to issue the Common Stock in
accordance with Section 13.1 upon an appropriate election by the Holder or
Holders of the Debentures to convert the Debentures into shares of Common Stock;

                                      46
<PAGE>

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

               (f) the institution by the Company of proceedings to be
adjudicated as bankrupt or insolvent, or the consent by it to the institution of
bankruptcy or insolvency proceedings against it, or the filing by it of a
petition or answer or consent seeking reorganization or relief under any
applicable Federal or State bankruptcy, insolvency, reorganization or other
similar law, or the consent by it to the filing of any such petition or to the
appointment of a receiver, liquidator, assignee, trustee, sequestrator (or other
similar official) of the Company or of substantially all 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 and
its willingness to be adjudicated as bankrupt, or the taking of corporate action
by the Company in furtherance of any such action.

          Section 5.2  Acceleration of Maturity; Rescission and Annulment.  If
                       --------------------------------------------------
an Event of Default occurs and is continuing, then and in every such case the
Trustee or the Holders of not less than 25% in principal amount of the
Outstanding Debentures of any series may declare the principal amount of all the
Debentures of such series to be due and payable immediately, by a notice in
writing to the Company (and to the Trustee if given by Holders); [provided that,
if upon an Event of Default, the Trustee or the Holders of not less than 25% in
principal amount of the Outstanding Debentures fail to declare the principal of
all the Debentures to be immediately due and payable, the holders of at least
25% in aggregate liquidation amount of the Preferred Securities then outstanding
shall have such right by a notice in writing to the Company and the Trustee,]
and upon any such declaration such principal amount (or specified amount) of and
the accrued interest (including any Additional Interest) on all the Debentures
shall become immediately due and payable, provided that the payment of principal
and interest (including any Additional Interest) on the Debentures shall remain
subordinated to the extent provided in Article 12.

                                      47
<PAGE>

          At any time after such a declaration of acceleration with respect to
Debentures 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
Debentures, by written notice to the Company and the Trustee may rescind and
annul such declaration and its consequences if:

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

                    (A) all overdue installments of interest (including any
          Additional Interest) on the Debentures;

                    (B) the principal of (and premium, if any, on) the
          Debentures which have become due otherwise than by such declaration of
          acceleration and interest thereon at the rate borne by the Debentures;

                    (C) to the extent that payment of such interest is lawful,
          interest (including any Additional Interest) upon overdue installments
          of interest at the rate borne by the Debentures;

                    (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

               (ii) all Events of Default with respect to Debentures, other
     than the non-payment of the principal of the Debentures which has become
     due solely by such acceleration, have been cured or waived as provided in
     Section 5.13. [If the Holders of a majority in principal amount of the
     Outstanding Debentures fail to rescind and annul such declaration and its
     consequences, the holders of a majority in liquidation amount of the
     Preferred Securities then outstanding shall have such right.]

          Section 5.3  Collection of Indebtedness and Suits for Enforcement by
                       -------------------------------------------------------
Trustee.
-------

          The Company covenants that if:

                                      48
<PAGE>

               (a) default is made in the payment of any installment of interest
(including any Additional Interest) on the Debentures when such interest becomes
due and payable and such default continues for a period of 30 days, or

               (b) default is made in the payment of the principal of (and
premium, if any, on) the Debentures whether at the Stated Maturity thereof or
upon redemption, by declaration or otherwise, the Company will, upon demand of
the Trustee, pay to it, for the benefit of the Holders of the Debentures, the
whole amount then due and payable on the Debentures for principal (and premium,
if any) and interest (including any Additional Interest), including, to the
extent that payment of such interest shall be lawful, interest on any overdue
principal (and premium, if any) and on any overdue installments of interest
(including any Additional Interest) at the rate borne by the Debentures, and, in
addition thereto, all amounts owing the Trustee under Section 6.7.

          If the Company fails to pay such amounts forthwith upon such demand,
the Trustee, in its own name and as trustee of an express trust, may institute a
judicial proceeding for the collection of the sums so due and unpaid, and may
prosecute such proceeding to judgement or final decree, and may enforce the same
against the Company or any other obligor upon the Debentures and collect the
moneys adjudged or decreed to be payable in the manner provided by law out of
the property of the Company or any other obligor upon the Debentures, wherever
situated.

          If an Event of Default occurs and is continuing, the Trustee may in
its discretion proceed to protect and enforce its rights and the rights of the
Holders of the Debentures 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 5.4  Trustee May File Proofs of Claim.  In case of the
                       --------------------------------
pendency of any receivership, insolvency, liquidation, bankruptcy,
reorganization, arrangement, adjustment, composition or other judicial
proceeding relative to the Company or any other obligor upon the Debentures:

               (a) the Trustee (irrespective of whether the principal of the
Debentures shall then be due and payable as therein expressed or by declaration
or

                                      49
<PAGE>

otherwise and irrespective of whether the Trustee shall have made any demand on
the Company for the payment of overdue principal (and premium, if any) or
interest (including any Additional Interest)) shall be entitled and empowered,
by intervention in such proceeding or otherwise,

                    (i)   to file and prove a claim for the whole amount of
     principal (and premium, if any) and interest (including any Additional
     Interest) owing and unpaid in respect to the Debentures and to file such
     other papers or documents as may be necessary or advisable and to take any
     and all actions as are authorized under the Trust Indenture Act in order to
     have the claims of the Holders and any predecessor to the Trustee under
     Section 6.7 allowed in any such judicial proceedings; and

                    (ii)  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 in accordance with Section 5.6;
     and

               (b)  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 for
distribution in accordance with Section 5.6, and in the event that the Trustee
shall consent to the making of such payments directly to the Holders, to pay to
the Trustee any amount due to it and any predecessor Trustee under Section 6.7;

          Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder any plan of
reorganization, arrangement, adjustment or composition affecting the Debentures
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 5.5  Trustee May Enforce Claim Without Possession of
                       -----------------------------------------------
Debentures.  All rights of action and claims under this Indenture or the
----------
Debentures may be prosecuted and enforced by the Trustee without the possession
of any of the Debentures 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 judgement
shall, after provision for the payment of

                                      50
<PAGE>

all the amounts owing the Trustee and any predecessor Trustee under Section 6.7,
its agents and counsel, be for the ratable benefit of the Holders of the
Debentures in respect of which such judgement has been recovered.

          Section 5.6  Application of Money Collected.  Any money or property
                       ------------------------------
collected or to be applied by the Trustee with respect to the Debentures
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 or
property on account of principal (or premium, if any) or interest (including any
Additional Interest), upon presentation of the Debentures 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 and any
predecessor Trustee under Section 6.7;

          SECOND:  To the payment of the amounts then due and unpaid upon the
Debentures for principal (and premium, if any) and interest (including any
Additional Interest), 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 the Debentures for principal (and
premium, if any) and interest (including any Additional Interest), respectively;

          THIRD:  The balance, if any, to the Person or Persons entitled
thereto; and

          FOURTH:  To the Company.

          Section 5.7  Limitation on Suits.  No Holder of the Debentures[,
                       -------------------
including a holder of Preferred Securities acting to enforce the rights of the
Property Trustee as a Holder of the Debentures pursuant to Section 6.8 of the
Trust Agreement,] shall have any right to institute any proceeding, judicial or
otherwise, with respect to this Indenture or for the appointment of a receiver,
assignee, trustee, liquidator, sequestrator (or other similar official) or for
any other remedy hereunder, unless:

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

                                      51
<PAGE>

               (b) [if the Trust is not the sole Holder of the Outstanding
Debentures,] the Holders of not less than 25% in principal amount of the
Outstanding Debentures shall have made written request to the Trustee to
institute proceedings in respect of such Event of Default in its own name as
Trustee hereunder;

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

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

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

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
Holders of the Debentures, 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 such Holders.

          Section 5.8  Unconditional Right of Holders to Receive Principal,
                       ----------------------------------------------------
Premium and Interest.  Notwithstanding any other provision in this Indenture,
--------------------
the Holder of any Debenture shall have the right which is absolute and
unconditional to receive payment of the principal of (and premium, if any) and
(subject to Section 3.7) interest (including any Additional Interest) on such
Debenture on the Maturity [or to convert such Debenture in accordance with
Article 13] and to institute suit for the enforcement of any such payment and
right to convert, and such right shall not be impaired without the consent of
such Holder. [For so long as any Preferred Securities remain Outstanding, to the
fullest extent permitted by law and subject to the terms of this Indenture and
the Trust Agreement, upon an Event of Default specified in Sections 5.1(a) or
5.1(b), any holder of Preferred Securities shall have the right to institute a
proceeding directly against the Company, for enforcement of payment to such
holder of the principal amount of or interest on Debentures having a principal
amount equal to the liquidation amount of the Preferred Securities of such
holder (a "Direct Action"). Notwithstanding any payment made to such holder of
Preferred Securities by the Company in connection with a Direct Action, the
Company shall

                                      52
<PAGE>

remain obligated to pay the principal of or interest on the Debentures held by
the Trust or the Property Trustee. In connection with any such Direct Action,
the rights of the Company will be subrogated to the rights of any holder of the
Preferred Securities to the extent of any payment made by the Company to such
holder of Preferred Securities as a result of such Direct Action. Except as set
forth in this Section, the holders of Preferred Securities shall have no right
to execute any right or remedy available to the Holders of or in respect of, the
Debentures.]

          Section 5.9  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 the Company, the Trustee and the Holder shall, subject to
any determination in such proceeding, be restored severally and respectively to
their former positions hereunder, and thereafter all rights and remedies of the
Trustee and the Holders shall continue as though no such proceeding had been
instituted.

          Section 5.10 Rights and Remedies Cumulative.  Except as otherwise
                       ------------------------------
provided in the last paragraph of Section 3.6, no right or remedy herein
conferred upon or reserved to the Trustee or to the Holders is intended to be
exclusive of any other right or remedy, and every right and remedy shall, to the
extent permitted by law, be cumulative and in addition to every other right and
remedy given hereunder or now or hereafter existing at law or in equity or
otherwise.  The assertion or employment of any right or remedy hereunder, or
otherwise, shall not prevent the concurrent assertion or employment of any other
appropriate right or remedy.

          Section 5.11 Delay or Omission Not Waiver.  No delay or omission of
                       ----------------------------
the Trustee or of any Holder of the Debentures 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 5.12 Control by Holders.  The Holders of a majority in
                       ------------------
principal amount of the Outstanding Debentures of any series shall have the
right to direct the time, method and place of conducting any proceeding for any
remedy available to the

                                      53
<PAGE>

Trustee or exercising any trust or power conferred on the Trustee, with respect
to the Debentures of such series, provided that:

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

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

               (c) subject to the provisions of Section 6.1, the Trustee shall
have the right to decline to follow such direction if the Trustee in good faith
shall, by a Responsible Officer or Officers of the Trustee, determine that the
proceeding so directed would be unjustly prejudicial to the Holders not joining
in any such direction or would involve the Trustee in personal liability.

          Upon receipt by the Trustee of any written notice directing the time,
method or place of conducting any such proceeding or exercising any such trust
or power, with respect to the Debentures and, if all or part of the Debentures
is represented by a Global Security, a record date shall be established for
determining Holders of Outstanding Debentures entitled to join in such notice,
which record date shall be at the close of business on the day the Trustee
receives such notice.  The Holders on such record date, or their duly designated
proxies, and only such Persons, shall be entitled to join in such notice,
whether or not such Holders remain Holders after such record date, provided,
                                                                   --------
that, unless the Holders of a majority in principal amount of the Outstanding
Debentures shall have joined in such notice prior to the day which is 90 days
after such record date, such notice shall automatically and without further
action by any Holder be canceled and of no further effect.  Nothing in this
paragraph shall prevent a Holder, or a proxy of a Holder, from giving, after
expiration of such 90-day period, a new notice identical to a notice which has
been canceled pursuant to the proviso to the preceding sentence, in which event
a new record date shall be established pursuant to the provisions of this
Section 5.12.

          Section 5.13 Waiver of Past Defaults.  Subject to Section 9.2 hereof,
                       -----------------------
the Holders of not less than a majority in principal amount of the Outstanding
Debentures of any series may on behalf of the Holders of all the Debentures
of such series waive any past default hereunder with respect to Debentures and
its consequences, except a default:

               (a) in the payment of the principal of (or premium, if any) or
interest (including any Additional Interest) on the Debentures (unless such
default

                                      54
<PAGE>

has been cured and a sum sufficient to pay all matured installments of interest
and principal due otherwise than by acceleration has been deposited with the
Trustee), or

               (b) in respect of a covenant or provision hereof which under
Article 9 cannot be modified or amended without the consent of the Holder of
each Outstanding Debenture[; provided, however, that if the Debentures are held
                             --------  -------
by the Trust or a trustee of the Trust, such waiver shall not be effective until
the holders of a majority in liquidation amount of Preferred Securities shall
have consented to such waiver; provided, further, that if the consent of the
                               --------  -------
Holder of each outstanding Debenture is required, such waiver shall not be
effective until each holder of the Trust Securities shall have consented to such
waiver].

          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.  [If the Holders of a
majority in aggregate principal amount of the Outstanding Debentures fail to
waive such Event of Default, the holders of a majority in aggregate liquidation
amount of Preferred Securities shall have such right.]  No such rescission shall
affect any subsequent default or impair any right consequent thereon.

          Section 5.14 Undertaking for Costs.  All parties to this Indenture
                       ---------------------
agree, and each Holder of any Debenture by his acceptance thereof shall be
deemed to have agreed, that any court may in its discretion require, in any suit
for the enforcement of any right or remedy under this Indenture, or in any suit
against the Trustee for any action taken or omitted by it as Trustee the filing
by any party litigant in such suit of an undertaking to pay the costs of such
suit, and that such court may in its discretion assess reasonable costs,
including reasonable attorneys' fees, against any party litigant in such suit,
having due regard to the merits and good faith of the claims or defenses made by
such party litigant; but the provisions of this Section shall not apply to any
suit instituted by the Trustee, to any suit instituted by any Holder, or group
of Holders, holding in the aggregate more than 10% in principal amount of the
Outstanding Debentures, or to any suit instituted by any Holder for the
enforcement of the payment of the principal of (or premium, if any) or interest
(including any Additional Interest) on the Debentures on or after the Maturity
of the Debentures or to convert a Debenture in accordance with Article 13.

          Section 5.15 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

                                      55
<PAGE>

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 VI

                                  THE TRUSTEE

          Section 6.1  Certain Duties and Responsibilities.  (a)  Except during
                       -----------------------------------
the continuance of an Event of Default,

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

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

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

                                      56
<PAGE>

                 (c)   No provision of this Indenture shall be construed to
relieve the Trustee from liability for its own negligent action, its own
negligent failure to act, or its own willful misconduct except that

                       (i)   this Subsection shall not be construed to limit the
     effect of Subsection (a) of this Section;

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

                       (iii) the Trustee shall not be liable with respect to any
     action taken or omitted to be taken by it in good faith in accordance with
     the direction of Holders pursuant to Section 5.12 relating to the time,
     method and place of conducting any proceeding for any remedy available to
     the Trustee, or exercising any trust or power conferred upon the Trustee,
     under this Indenture.

                 (d)   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 there shall be reasonable grounds for believing that
repayment of such funds or adequate indemnity against such risk or liability is
not reasonably assured to it.

                 (e)   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 6.2 Notice of Defaults. Within 90 days after actual knowledge
                      ------------------
by a Responsible Officer of the Trustee of the occurrence of any default
hereunder, the Trustee shall transmit by mail to all Holders of Debentures, as
their names and addresses appear in the Securities Register, notice of such
default hereunder known to the Trustee, unless such default shall have been
cured or waived; provided, however, that, except in the case of a default in the
payment of the principal of (or premium, if any) or interest (including any
Additional Interest) on Debenture, the Trustee shall be protected in withholding
such notice if and so long as the board of directors, the executive committee or
a trust committee of directors and/or Responsible Officers of the Trustee in
good faith determines that the withholding of

                                      57
<PAGE>

such notice is in the interests of the Holders of Debentures; and provided,
                                                                  --------
further, that, except in the case of any default of the character specified in
-------
Section 5.1(c), no such notice to Holders of the Debentures shall be given until
at least 30 days after the occurrence thereof. For the purpose of this Section,
the term "default" means any event which is, or after notice or lapse of time or
both would become, an Event of Default.

          Section 6.3  Certain Rights of Trustee.  Subject to the provisions of
                       -------------------------
Section 6.1:

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

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

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

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

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

                                      58
<PAGE>

               (f)  the Trustee is not required to expend or risk its own funds
or otherwise incur personal financial liability in the performance of its duties
if the Trustee reasonably believes that repayment or adequate indemnity is not
reason ably assured to it.

               (g)  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,
indenture, Debenture or other paper or document, but the Trustee in its
discretion may make such inquiry or investigation into such facts or matters as
it may see fit, and, if the Trustee shall determine to make such inquiry or
investigation, it shall be entitled to examine the books, records and premises
of the Company, personally or by agent or attorney;

               (h)  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 any part of any agent or attorney appointed with due care by it
hereunder; and

               (i)  the Trustee shall not be charged with knowledge of any
default unless either (i) a Responsible Officer shall have actual knowledge
thereof, or (ii) the Trustee shall have received written notice thereof from the
Company or any Holder of the Debentures.

          Section 6.4  Not Responsible for Recitals or Issuance of Debentures.
                       ------------------------------------------------------
The recitals contained herein and in the Debentures, except the Trustee's
certificates of authentication, shall be taken as the statements of the Company,
and the Trustee assumes no responsibility for their correctness.  The Trustee
makes no representations as to the validity or sufficiency of this Indenture
or of the Debentures.  The Trustee shall not be accountable for the use or
application by the Company of the Debentures or the proceeds thereof.

          Section 6.5  May Hold Debentures.  The Trustee, any Paying Agent,
                       -------------------
Securities Registrar or any other agent of the Company, in its individual or any
other capacity, may become the owner or pledgee of Debentures and, subject to
Sections 6.8 and 6.13, may otherwise deal with the Company with the same rights
it would have if it were not Trustee, Paying Agent, Securities Registrar or such
other agent.

          Section 6.6  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 of interest on any money
received by it hereunder except as otherwise agreed in writing with the Company.

          Section 6.7  Compensation and Reimbursement.  The Company agrees
                       ------------------------------

                                      59
<PAGE>

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

               (b)   to reimburse the Trustee 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); and

               (c)   to indemnify the Trustee for, and to hold it harmless
against, any loss, liability or expense (including the reasonable compensation
and the expenses and disbursements of its agents and counsel) incurred without
negligence or bad faith, arising out of or in connection with the acceptance or
administration of this trust or the performance of its duties 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. This indemnification shall survive the resignation or removal
of the Trustee and the termination of this Indenture.

          To secure the Company's payment obligations in this Section, the
Company and the Holders agree that the Trustee shall have a lien prior to the
Debentures on all money or property held or collected by the Trustee except
assets held in trust to pay principal and premium, if any, or interest on
particular Debentures pursuant to the discharge and defeasance provisions
pursuant to Article 4, or pursuant to any redemption pursuant to Article 11
hereof if monies have been deposited for such redemption and notice has been
given and the Redemption Date has passed.  Such lien shall survive the
satisfaction and discharge of this Indenture.

          When the Trustee incurs expenses or renders services after an Event of
Default specified in Section 5.1(e) or (f) occurs, the expenses and the
compensation for the services are intended to constitute expenses of
administration under any Bankruptcy Reform Act of 1978 or a successor statute.

          Section 6.8  Disqualification; Conflicting Interests.  The Trustee
                       ---------------------------------------
shall be subject to the provisions of Section 310(b) of the Trust Indenture Act.
Nothing herein shall prevent the Trustee from filing with the Commission the
application referred to in the second to last paragraph of Section 310(b) of the
Trust Indenture

                                      60
<PAGE>

Act. The Trust Agreement and the Guarantee shall be deemed to be specifically
described in this Indenture for the purposes of clause (i) of the first proviso
contained in Section 310(b) of the Trust Indenture Act. The Trustee's services
as Guarantee Trustee and Trustee under the Trust Agreement shall not be deemed
to constitute conflicting interests.

          Section 6.9  Corporate Trustee Required; Eligibility.  There shall at
                       ---------------------------------------
all times be a Trustee hereunder which shall be

               (a)  a corporation organized and doing business under the laws of
the United States of America or of any State, Territory or the District of
Columbia, authorized under such laws to exercise corporate trust powers and
subject to supervision or examination by Federal, State, Territorial or District
of Columbia authority, or

               (b)  a corporation or other Person organized and doing business
under the laws of a foreign government that is permitted to act as Trustee
pursuant to a rule, regulation or order of the Commission, authorized under such
laws to exercise corporate trust powers, and subject to supervision or
examination by authority of such foreign government or a political subdivision
thereof substantially equivalent to supervision or examination applicable to
United States institutional trustees,

          in either case having a combined capital and surplus of at least
$50,000,000, subject to supervision or examination by Federal or State
authority.  If such corporation publishes reports of condition at least
annually, pursuant to law or to the requirements of the aforesaid supervising or
examining authority, then, to the purposes of this Section, the combined capital
and surplus of such corporation shall be deemed to be its combined capital and
surplus as set forth in its most recent report of condition so published.  If at
any time the Trustee shall cease to be eligible in accordance with the
provisions of this Section, it shall resign immediately in the manner and with
the effect hereinafter specified in this Article.  Neither the Company nor any
Person directly or indirectly controlling, controlled by or under common control
with the Company shall serve as Trustee hereunder.

          Section 6.10 Resignation and Removal; Appointment of Successor. (a)
                       -------------------------------------------------
No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee under Section 6.11.

                                      61
<PAGE>

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

               (c)  The Trustee may be removed at any time by Act of the Holders
of a majority in principal amount of the Outstanding Debentures, delivered to
the Trustee and to the Company. If an instrument of acceptance by a successor
Trustee shall not have been delivered to the Trustee within 30 days after the
giving of such notice of resignation, the resigning Trustee may petition any
court of competent jurisdiction for the appointment of a successor Trustee.

               (d)  If at any time:

                    (i)   the Trustee shall fail to comply with Section 6.8
     after written request therefor by the Company or by any Holder who has been
     a bona fide Holder of a Debenture for at least six months, or

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

                    (iii) the Trustee shall become incapable of acting or shall
     be adjudged as 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 Board  Resolution may remove the
Trustee, or (B) subject to Section 5.14, any Holder who has been a bona fide
Holder of a Debenture for at least six months may, on behalf of himself and all
other similarly situated Holders, petition any court of competent jurisdiction
for the removal of the Trustee and the appointment of a successor Trustee.

               (e)  If the Trustee shall resign, be removed or become incapable
of acting, or if a vacancy shall occur in the office of Trustee for any cause
with respect to the Debentures, the Company, by a Board Resolution, shall
promptly

                                      62
<PAGE>

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

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

          Section 6.11 Acceptance of Appointment by Successor.  (a)  In case of
                       --------------------------------------
the appointment hereunder of a successor Trustee, 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.

               (b)  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 rights, power and trusts referred
to in paragraph (a) of this Section.

                                      63
<PAGE>

               (c)  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 6.12 Merger, Conversion, Consolidation or Succession to
                       --------------------------------------------------
Business.  Any corporation into which the Trustee may be merged or converted or
--------
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee and any agency
appointments of the Trustee hereunder, provided such corporation shall be
otherwise qualified and eligible under this Article, without the execution or
filing of any paper or any further act on the part of any of the parties hereto.
In case any Debentures 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
Debentures so authenticated, and in case any Debentures shall not have been
authenticated, any successor to the Trustee may authenticate such Debentures
either in the name of any predecessor Trustee or in the name of such successor
Trustee, and in all cases the certificate of authentication shall have the full
force which it is provided anywhere in the Debentures or in this Indenture that
the certificate of the Trustee shall have.

          Section 6.13 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 Debentures), the Trustee shall be subject to the provisions of
the Trust Indenture Act regarding the collection of claims against the Company
(or any such other obligor).

          Section 6.14 Appointment of Authenticating Agent.  The Trustee may
                       -----------------------------------
appoint an Authenticating Agent or Agents with respect to the Debentures which
shall be authorized to act on behalf of the Trustee to authenticate the
Debentures issued upon exchange, registration of transfer or partial redemption
thereof, and Debentures 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 Debentures 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.  Each Authenticating Agent shall be acceptable to the
Company and shall at all times be a corporation organized and

                                      64
<PAGE>

doing business under the laws of the United States of America, or of any State,
Territory 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 Authenti cating Agent shall
resign immediately in the manner and with the effect specified in this Section.

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

          An Authenticating Agent may resign at any time by giving written
notice thereof to the Trustee and to the Company.  The Trustee may at any time
terminate the agency of an Authenticating Agent by giving written notice thereof
to such Authenticating Agent and to the Company.  Upon receiving such a notice
of resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent which shall be acceptable to the Company and shall give notice of such
appointment in the manner provided in Section 1.6 to all Holders of the
Debentures.  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 provision of this Section.

          The Company agrees to pay to each Authenticating Agent from time to
time reasonable compensation for its services under this Section.

                                      65
<PAGE>

          If an appointment is made pursuant to this Section, the Debentures 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 Debentures referred to in the within mentioned
indenture.



                                   CHASE MANHATTAN TRUST COMPANY, National
                                   Association
                                   As Trustee

                                   By: _________________________
                                        As Authenticating Agent


                                   By: _______________________
                                        Authorized Officer

                                      66
<PAGE>

                                  ARTICLE VII

               HOLDERS LISTS AND REPORTS BY TRUSTEE AND COMPANY

          Section 7.1  Company to Furnish Names and Addresses of Holders. The
                       -------------------------------------------------
Company will furnish or cause to be furnished to the Trustee (unless the Trustee
is acting as the Securities Registrar).

               (a)  quarterly at least 5 Business Days before each Interest
Payment Date, a list, in such form as the Trustee may reasonably require, of the
names and addresses of the Holders as of each such date.

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

          Section 7.2  Preservation of Information; Communications to Holders.
                       ------------------------------------------------------
(a)  The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in Section 7.1 and the names and
addresses of Holders received by the Trustee in its capacity as Securities
Registrar.  The Trustee may destroy any list furnished to it as provided in
Section 7.1 upon receipt of a new list so furnished.

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

               (c)  Every Holder of Debentures, 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
the disclosure of information as to the names and addresses of the Holders made
pursuant to the Trust Indenture Act.

          Section 7.3  Reports by Trustee.  (a)  The Trustee shall transmit to
                       ------------------
Holders such reports concerning the Trustee and its actions under this Indenture
as

                                      67
<PAGE>

may be required pursuant to the Trust Indenture Act, at the times and in the
manner provided pursuant thereto.

               (b)  Reports so required to be transmitted at stated intervals of
not more than 12 months shall be transmitted within 60 days after May 15 of each
year, commencing with the first May 15 after the first issuance of Debentures
under this Indenture.

               (c)  A copy of each such report shall, at the time of such
transmission to Holders, be filed by the Trustee with each stock exchange or
self regulatory organization of which the Trustee has received notice by the
Company upon which the Debentures are listed and also with the Commission. The
Company will notify the Trustee whenever the Debentures are listed on any stock
exchange or with any self-regulatory organization.

          Section 7.4  Reports by Company.  The Company shall file with the
                       ------------------
Trustee and with 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 in
the Trust Indenture Act, provided that any such information, documents or
                         --------
reports required to be filed with the Commission pursuant to Section 13 or
Section 15(d) of the Securities Exchange Act of 1934 shall be filed with the
Trustee within 15 days after the same is required to be filed with the
Commission. [Notwithstanding that the Company may not be required to remain
subject to the reporting requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Company shall continue to file with the Commission and
provide the Trustee and Holders with the annual reports and the information,
documents and other reports which are specified in Sections 13 and 15(d) of the
Securities Exchange Act of 1934.]  The Company also shall comply with the other
provisions of Trust Indenture Act Section 314(a).

                                  ARTICLE VII

             CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

          Section 8.1  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 no Person shall consolidate with or merge into the Company or
convey,
                                      68
<PAGE>

transfer or lease its properties and assets substantially as an entirety to the
Company, unless:

               (a)  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 organized and
existing under the laws of the United States of America or any State or the
District of Columbia, and shall expressly assume, by an indenture supplemental
hereto, executed and delivered to the Trustee, in form satisfactory to the
Trustee, the due and punctual payment of the principal of (and premium, if any)
and interest (including any Additional Interest) on all the Debentures and the
performance of every covenant of this Indenture on the part of the Company to be
performed or observed and shall have provided for conversion rights in
accordance with Article 13;

               (b)  immediately after giving effect to 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 occurred and be continuing;

              [(c)  such consolidation, merger, conveyance, transfer or lease is
permitted under the Trust Agreement and Guarantee and does not give rise to any
breach or violation of the Trust Agreement or Guarantee;] and

               (d)  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 any such supplemental indenture
complies with this Article and that all conditions precedent herein provided for
relating to such transaction have been complied with, and the Trustee, subject
to Section 6.1, may rely upon such Officers' Certificate and Opinion of Counsel
as conclusive evidence that such transaction complies with this Section 8.1.

          Section 8.2  Successor Corporation Substituted.  Upon any consolida-
                       ---------------------------------
tion or merger by the Company with or into any other Person, or any conveyance,
transfer or lease by the Company of its properties and assets substantially as
an entirety to any Person in accordance with Section 8.1, the successor
corporation 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

                                      69
<PAGE>

may exercise every right and power of, the Company under this Indenture with the
same effect as if such successor corporation had been named as the Company
herein; and in the event of any such conveyance, transfer or lease the Company
shall be discharged from all obligations and covenants under the Indenture and
the Deben tures and may be dissolved and liquidated.

          Such successor corporation may cause to be signed, and may issue
either in its own name or in the name of the Company, any or all of the
Debentures issuable hereunder which theretofore shall not have been signed by
the Company and delivered to the Trustee, and, upon the Company Order of such
successor corporation instead of the Company and subject to all the terms,
conditions and limitations in this Indenture prescribed, the Trustee shall
authenticate and shall deliver any Debentures which previously shall have been
signed and delivered by the officers of the Company to the Trustee for
authentication pursuant to such provisions and any Debentures which such
successor corporation thereafter shall cause to be signed and delivered to the
Trustee on its behalf for the purpose pursuant to such provisions. All the
Debentures so issued shall in all respects have the same legal rank and benefit
under this Indenture as the Debentures theretofore or thereafter issued in
accordance with the terms of this Indenture as though all of such Debentures had
been issued at the date of the execution hereof.

          In case of any such consolidation, merger, sale, conveyance or lease,
such changes in phraseology and form may be made in the Debentures thereafter to
be issued as may be appropriate.

                                  ARTICLE IX

                            SUPPLEMENTAL INDENTURES

          Section 9.1  Supplemental Indentures Without Consent of Holders.
                       --------------------------------------------------
Without the consent of or notice to any Holder, 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:

               (a)  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 Debentures contained; or

                                      70
<PAGE>

               (b)  to convey, transfer, assign, mortgage or pledge any property
to or with the Trustee or to surrender any right or power herein conferred upon
the Company; or

               (c)  to add to covenants of the Company for the benefit of the
Holders of the Debentures or to surrender any right or power herein conferred
upon the Company; or

               (d)  to make provision with respect to the conversion rights of
Holders pursuant to the requirements of Article 13; or

               (e)  to add any additional Events of Default; or

               (f)  to cure any ambiguity, to correct or supplement any
provision herein which may be 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 shall not
materially adversely affect the interest of the Holders of Debentures [and for
so long as any of the Preferred Securities shall remain outstanding, the holders
of such Preferred Securities]; or

               (g)  to evidence and provide for the acceptance of appointment
hereunder by successor Trustee 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 Trust hereunder by more than one Trustee, pursuant to the
requirements of Section 6.11(b); or

               (h)  to comply with the requirements of the Commission in order
to effect or maintain the qualification of this Indenture under the Trust
Indenture Act; or

               (i)  to make provision for transfer procedures, certification,
book-entry provisions, the form of restricted securities legends, if any, to be
placed on Debentures, and all other matters required pursuant to Section 3.5 [or
otherwise necessary, desirable or appropriate in connection with the issuance of
Debentures to holders of Preferred Securities in the event of a distribution of
Debentures by the Trust if a Special Event occurs and is continuing.]

                                      71
<PAGE>

          Section 9.2  Supplemental Indentures with Consent of Holders.  With
                       -----------------------------------------------
the consent of the Holders of not less than a majority in principal amount of
the Outstanding Debentures, 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 the Debentures under this Indenture; provided, however, that no such
supplemental indenture shall, without the consent of the Holder of each
Outstanding Debenture affected thereby,

               (a)  except to the extent permitted by Section 3.11 with respect
to the extension of the interest payment period of the Debentures, change the
Stated Maturity of the principal of, or any installment of interest (including
any Additional Interest) on, the Debentures, or reduce the principal amount
thereof or the rate of interest thereon or reduce any premium payable upon the
redemption thereof, or change the place of payment where, or the coin or
currency in which, any Debenture or interest thereon is payable, or impair the
right to institute suit for the enforcement of any such payment on or after the
Maturity thereof (or, in the case of redemption, on or after the date fixed for
redemption thereof), or

               (b)  adversely affect any right to convert or exchange any
Debenture or modify the provisions of this Indenture with respect to the
subordination of the Debentures in a manner adverse to such Holder; or

               (c)  reduce the percentage in principal amount of the Outstanding
Debentures, 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

               (d)  modify any of the provisions of this Section, Section 4.1,
Section 5.8, Section 5.13, 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 Debenture affected thereby[, or the
consent of the holders of all the Preferred Securities as the case may be]; [or

                                      72
<PAGE>

provided that, so long as any Preferred Securities remain outstanding no
-------- ----
termination of this Indenture shall occur, and no waiver of any Event of Default
or compliance with any covenant under this Indenture shall be effective, without
the prior consent of the holders of at least a majority of the aggregate
liquidation amount of such Preferred Securities then outstanding unless and
until the principal (and premium, if any) of the Debentures and all accrued and
unpaid interest (including any Additional Interest) thereon have been paid in
full.]

          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 9.3  Execution of Supplemental Indentures.  In executing or
                       ------------------------------------
accepting the additional trusts created by any supplemental indenture permitted
by this Article or the modifications thereby of the trust created by this
Indenture, the Trustee shall be entitled to receive, and (subject to Section
6.1) shall be fully protected in relying upon, an Officers' Certificate and an
Opinion of Counsel stating that the execution of such supplemental indenture is
authorized or permitted by this Indenture, and that all conditions precedent
have been complied with.  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 9.4  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 the Debentures theretofore
or thereafter authenticated and delivered hereunder shall be bound thereby.

          Section 9.5  Conformity with Trust Indenture Act.  Every supplemental
                       -----------------------------------
indenture executed pursuant to this Article shall conform to the requirements of
the Trust Indenture Act as then in effect.

          Section 9.6  Reference in Debentures to Supplemental Indentures.
                       --------------------------------------------------
Debentures 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 Debentures
so modified as to conform, in the opinion of the Trustee and the Board of
Directors, to

                                      73
<PAGE>

any such supplemental indenture may be prepared and executed by the Company and
authenticated and delivered by the Trustee in exchange for Outstanding
Debentures presented to the Trustee.

                                   ARTICLE X

                                   COVENANTS

          Section 10.1   Payment of Principal, Premium and Interest.  The
                        -------------------------------------------
Company covenants and agrees for the benefit of the Holders of the Debentures
that it will duly and punctually pay the principal of (and premium, if any) and
interest (including Additional Interest) on the Debentures in accordance with
the terms of the Debentures and this Indenture.

              Section 10.2 Maintenance of Office or Agency.  The Company will
              --------------------------------------------
maintain in the United States an office or agency where Debentures may be
presented or surrendered for payment and an office or agency where Debentures
may be surrendered for registration of transfer or exchange and where notices
and demands to or upon the Company in respect of the Debentures and this
Indenture may be served. The Company initially appoints the Trustee, acting
through its Corporate Trust Office, as its agent for said purposes. The Company
will give prompt written notice to the Trustee of any change in the location of
any such office or agency. If at any time the Company shall fail to maintain
such 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.

                                      74
<PAGE>


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

          Section 10.3 Money for Debenture Payments to Be Held in Trust.  If the
                       ------------------------------------------------
Company shall at any time act as its own Paying Agent with respect to the
Debentures, it will, on or before each due date of the principal of (and
premium, if any) or interest on any of the Debentures, segregate and hold in
trust for the benefit of the Persons entitled thereto a sum sufficient to pay
the principal (and premium, if any) or interest so becoming due until such sums
shall be paid to such Persons or otherwise disposed of as herein provided, and
will promptly notify the Trustee of its failure so to act.

          Whenever the Company shall have one or more Paying Agents, it will, on
or before each due date of the principal of or interest on the Debentures,
deposit with a Paying Agent a sum sufficient to pay the principal (and premium,
if any) or interest so becoming due, such sum to be held in trust for the
benefit of the Persons entitled to such principal and premium (if any) or
interest, and (unless such Paying Agent is the Trustee) the Company will
promptly notify the Trustee of its failure so to act.

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

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

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

                                      75
<PAGE>


          (c)  at any time during the continuance of any such default, upon the
written request of the Trustee, forthwith pay to the Trustee all sums so held in
trust by such Paying Agent; and

          (d)  comply with the provisions of the Trust Indenture Act applicable
to it as a Paying Agent.

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

          Any money deposited with the Trustee or any Paying Agent, or then held
by the Company, in trust for the payment of the principal of (and premium, if
any) or interest on any Debenture and remaining unclaimed for two years after
such principal (and premium, if any) or interest has become due and payable
shall (unless otherwise required by mandatory provision of applicable escheat or
abandoned or unclaimed property law) be paid on Company Request, after all
payments owing the Trustee have been paid, to the Company, or (if then held by
the Company) shall (unless otherwise required by mandatory provision of
applicable escheat or abandoned or unclaimed property law) be discharged from
such trust; and the Holder of such Debenture 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.

          Section 10.4 Payment of Taxes and Other Claims.  The Company will pay
                       ---------------------------------
or discharge or cause to be paid or discharged, before the same shall become
delinquent, (a) all taxes, assessments and governmental charges levied or
imposed upon the Company or upon the income, profits or property of the Company,
and (b) all lawful claims for labor, materials and supplies which, if unpaid,
might by law become a lien upon the property of the Company; 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.

                                      76
<PAGE>


          Section 10.5 Statement as to Compliance.  The Company shall deliver to
                       --------------------------
the Trustee, within 120 days after the end of each calendar year of the Company
ending after the date hereof an Officers' Certificate (signed by at least one of
the officers referred to in Section 314(a)(4) of the Trust Indenture Act)
covering the preceding calendar year, stating whether or not to the best
knowledge of the signers thereof the Company is in default in the performance,
observance or fulfillment of or compliance with any of the terms, provisions,
covenants and conditions of this Indenture, and if the Company shall be in
default, specifying all such defaults and the nature and status thereof of which
they may have knowledge.  For the purpose of this Section 10.5, compliance shall
be determined without regard to any grace period or requirement of notice
provided pursuant to the terms of this Indenture.

          Section 10.6 Waiver of Certain Covenants.  The Company may omit in any
                       ---------------------------
particular instance to comply with any covenant or condition set forth in this
Article 10, if before or after the time for such compliance the Holders of at
least a majority in principal amount of the Outstanding Debentures, by Act of
such Holders, either waive such compliance in such instance or generally waive
compliance with such covenant or condition, but no such waiver shall extend to
or affect such covenant or condition except to the extent so expressly waived,
and, until such waiver shall become effective, the obligations of the Company in
respect of any such covenant or condition shall remain in full force and effect.

          [Section 10.7 Additional Sums.  In the event that (a) the Property
                       ---------------
Trustee is the Holder of all of the Outstanding Debentures, (b) a Tax Event in
respect of the Trust shall have occurred and be continuing and (c) the Company
shall not have (i) redeemed the Debentures pursuant to Section 11.7 or 11.8 or
(ii) terminated the Trust pursuant to Section 9.2(b) of the Trust Agreement, the
Company shall pay to the Trust (and its permitted successors or assigns under
the Trust Agreement) for so long as the Trust (or its permitted successor or
assignee) is the registered holder of the Debentures, such additional amounts as
may be necessary in order that the amount of distributions (including any
Additional Amounts (as defined in the Trust Agreement)) then due and payable by
the Trust on the Preferred Securities and Common Securities that at any time
remain outstanding in accord with the terms thereof shall not be reduced as a
result of any Additional Taxes (the "Additional Sums").  Whenever in this
Indenture or the Debentures there is a reference in any context to the payment
of principal of or interest on the Debentures, such mention shall be deemed to
include mention of the payments of the Additional Sums provided for in this
paragraph to the extent that, in such context, Additional Sums are, were or
would be payable in respect thereof pursuant to the provisions of this paragraph
and express mention of the payment of Additional Sums (if applicable) in any
provisions hereof shall not be construed as excluding Additional Sums in those
provisions hereof where such express mention is not made; provided, however,
that the extension of an interest payment period pursuant to Section 3.11 or
the Debentures shall not extend the payment of any Additional Sums that may be
due and payable during such interest payment period.]

                                      77
<PAGE>


          Section 10.8 Additional Covenants.  The Company covenants and agrees
                       --------------------
with each Holder of Debentures that so long as the Debentures are outstanding,
if (i) there shall have occurred any event of which the Company has actual
knowledge that (A) with the giving of notice or the lapse of time or both, would
constitute an Event of Default hereunder and (B) in respect of which the Company
shall not have taken reasonable steps to cure, (ii) the Company shall be in
default with respect to its payment of any obligations under the Guarantee or
(iii) the Company shall have given notice of its selection of an Extension
Period as provided herein and shall not have rescinded such notice, or such
period, or any extension thereof, shall be continuing, then the Company shall
not, (a) declare or pay any dividend on, make distributions with respect to, or
redeem, purchase or make a liquidation payment with respect to, any of its
Common Stock (other than (i) purchases or acquisitions of shares of Common Stock
in connection with the satisfaction by the Company of its obligations under
any employee benefit plan, (ii) as a result of a reclassification of the
Company's Common Stock or the exchange or conversion of one class or series of
the Company's Common Stock for another class or series of the Company's Common
Stock, (iii) the purchase of fractional interests in shares of the Company's
Common Stock pursuant to the conversion or exchange provisions of such Common
Stock of the Company or the security being converted or exchanged or (iv)
purchases or acquisitions of shares of Common Stock to be used in connection
with acquisitions of Common Stock by shareholders pursuant to the Company's
dividend reinvestment plan) or make any guarantee payments with respect to the
foregoing and (b) the Company shall not make any payment of principal or
premium, if any, on or repurchase any debt securities (including guarantees)
other than at stated maturity issued by the Company which rank pari passu with
or junior to the Debentures.

          [The Company also covenants with each Holder of the Debentures (i)
that for so long as Preferred Securities are outstanding not to convert the
Debentures except pursuant to a notice of conversion delivered to the Conversion
Agent by a holder of Preferred Securities and (ii) to maintain directly or
indirectly 100% ownership of the Common Securities of the Trust; provided,
however, that any permitted successor of the Company hereunder may succeed to
the Company's ownership of such Common Securities, (iii) not to voluntarily
terminate, wind-up or liquidate the Trust, except (a) in connection with a
distribution of the Debentures to the holders of Preferred Securities in
liquidation of the Trust or (b) in connection with certain mergers,
consolidations or amalgamations permitted by the Trust Agreement and (iv) to use
its reasonable efforts, consistent with the terms and provisions of the Trust
Agreement to cause the Trust to remain a grantor trust and not to be classified
as an association taxable as a corporation for United States Federal income tax
purposes.]

                                      78
<PAGE>


          [Section 10.9 Payment of Expenses of the Trust. In connection with the
                       --------------------------------
offering, sale and issuance of the Debentures to the Property Trustee and in
connection with the sale of the Preferred Securities by the Trust, the Company
shall:

          (a)  pay for all costs, fees and expenses relating to the offering,
sale and issuance of the Preferred Securities (including commissions, discounts
and expenses in connection therewith) and compensation of the Trustee under the
Indenture in accordance with the provisions of Section 6.7 of the Indenture;

          (b)  be responsible for and pay for all debts and obligations (other
than with respect to the Preferred Securities) of the Trust, pay for all costs
and expenses of the Trust (including, but not limited to, costs and expenses
relating to the organization of the Trust, the offering, sale and issuance of
the Preferred Securities (including commissions, discounts and expenses in
connection therewith), the fees and expenses of the Property Trustee and the
Delaware Trustee, the costs and expenses relating to the operation of the Trust,
including without limitation, costs and expenses of accountants, attorneys,
statistical or bookkeeping services, expenses for printing and engraving and
computing or accounting equipment, paying agent(s), registrar(s), transfer
agent(s), duplicating, travel and telephone and other telecommunications
expenses and costs and expenses incurred in connection with the acquisition,
financing, and disposition of Trust assets); and

          (c)  pay any and all taxes (other than United States withholding
taxes attributable to the Trust or its assets) and all liabilities, costs and
expenses with respect to such taxes of the Trust.]

                                  ARTICLE XI

                     REDEMPTION OR EXCHANGE OF DEBENTURES

          Section 11.1 Election to Redeem; Notice to Trustee.  The election of
                       -------------------------------------
the Company to redeem any Debentures shall be evidenced by or pursuant to a
Board Resolution. In case of any redemption at the election of the Company, the
Company shall, not less than 45 days prior to the date fixed for redemption
(unless a shorter notice shall be satisfactory to the Trustee, at their
convenience), notify the Trustee in writing of such date and of the principal
amount of Debentures to be redeemed.

          Section 11.2 Selection of Debentures to Be Redeemed.  If less than all
                       --------------------------------------
the Debentures are to be redeemed, the particular Debentures to be redeemed
shall be selected not more than 45 days prior to the Redemption Date by the
Trustee from the Outstanding Debentures not previously called for redemption, by
lot or by such other 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 the Debentures Outstanding, provided that the unredeemed portion of
                                      --------
the principal amount of the Debentures be in an authorized denomination (which
shall not be less than the minimum authorized denomination) for the Debentures.

          The Trustee shall promptly notify the Company in writing of the
Debentures selected for partial redemption and the principal amount thereof to
be redeemed. For all purposes of this Indenture, unless the context otherwise
requires, all provisions relating to the redemption of Debentures shall relate,
in the case of any Debenture redeemed or to be redeemed only in part, to the
portion of the principal amount of such Debenture which has been or is to be
redeemed. If the Company shall so direct, Debentures registered in the name of
the Company, any Affiliate or

                                      79
<PAGE>

any Subsidiary thereof shall not be included in the Debentures selected for
redemption.

          Section 11.3 Notice of Redemption.  Notice of redemption shall be
                       --------------------
given by first-class mail, postage prepaid, mailed not later than the thirtieth
day, and not earlier than the sixtieth day, prior to the date fixed for
redemption, to each Holder of Debentures to be redeemed, at the address of such
Holder as it appears in the Securities Register.

          With respect to Debentures to be redeemed, each notice of redemption
shall state:

               (a)  the Redemption Date;

               (b)  the redemption price at which the Debentures are to be
redeemed (the "Redemption Price");

               (c)  if less than all Outstanding Debentures are to be redeemed,
the identification (and, in the case of partial redemption, the respective
principal amounts) of the particular Debentures to be redeemed (including, if
relevant, the CUSIP or ISIN number);

               (d)  that on the Redemption Date the Redemption Price will become
due and payable upon each such Debenture or portion thereof, and that upon
deposit with the Paying Agent interest thereon, if any, shall cease to accrue on
and after the Redemption Date;

               (e)  the place or places where the Debentures are to be
surrendered for payment of the redemption price at which the Debentures are to
be redeemed; and

               (f)  that a Holder of Debentures who desires to convert
Debentures called for redemption must satisfy the requirements for conversion
contained in the Debentures, the then existing conversion price or rate, and the
date and time when the option to convert shall expire.

          Notice of redemption of Debentures 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.
The notice if mailed in the manner herein provided shall be conclusively
presumed to

                                      80
<PAGE>

have been duly given, whether or not the Holder receives such notice. In any
case, a failure to give such notice by mail or any defect in the notice to the
Holder of any Debenture designated for redemption as a whole or in part shall
not affect the validity of the proceedings for the redemption of any other
Debenture.

          Section 11.4 Deposit of Redemption Price.  Prior to 10:00 a.m., New
                       ---------------------------
York City time, on the Redemption Date specified in the notice of redemption
given as provided in Section 11.3, the Company will deposit with the Trustee or
with one or more Paying Agents (or, if the Company is acting as its own Paying
Agent, segregate and hold in trust as provided in Article 4) an amount of money
sufficient to redeem on the Redemption Date all the Debentures so called for
redemption at the applicable Redemption Price.

          If any Debenture called for redemption has been converted, any money
deposited with the Trustee or with any Paying Agent or so segregated and held in
trust for the redemption of such Debenture shall (subject to any right of the
Holder of such Debenture or any Predecessor Debenture to receive interest as
provided in the last paragraph of Section 3.7) be paid to the Company upon
Company Request or, if then held by the Company, shall be discharged from such
trust.

          Section 11.5 Debentures Payable on Redemption Date.  If notice of
                       -------------------------------------
redemption has been given as provided in Section 11.3, the Debentures so to be
redeemed shall, on the Redemption Date, become due and payable at the Redemption
Price therein specified, including any accrued interest (and any Additional
Interest) thereon, and from and after such date (unless the Company shall
default in the payment of the Redemption Price or any accrued interest on
(including any Additional Interest)) such Debentures shall cease to bear
interest.  Upon surrender of any such Debenture for redemption in accordance
with said notice, such Debenture shall be paid by the Company at the Redemption
Price, including any accrued interest (and any Additional Interest) to the
Redemption Date, provided, however, that installments of interest on Debentures
                 --------  -------
whose Stated Maturity is on or prior to the Redemption Date shall be payable to
the Holders of such Debentures, or one of more Predecessor Debentures,
registered as such at the close of business on the relevant Regular Record Dates
or Special Record Dates, as the case may be, according to their terms and the
provisions of Section 3.7.

          If any Debenture called for redemption shall not be so paid upon
surrender thereof for redemption, the principal and any premium shall, until
paid,

                                      81
<PAGE>

bear interest from the Redemption Date at the rate prescribed therefor in the
Debenture.

          Section 11.6 Debentures Redeemed in Part.  In the event of any
                       ---------------------------
redemption in part, the Company shall not be required to (i) issue, register the
transfer of or exchange any Debenture during a period beginning at 9:00 a.m.
(New York City time) 15 Business Days before any selection for redemption of
Debentures and ending at 5:00 p.m. (New York City time) on the earliest date in
which the relevant notice of redemption is deemed to have been given to all
Holders of Debentures to be so redeemed and (ii) register the transfer of or
exchange any Debentures so selected for redemption, in whole or in part, except
for the unredeemed portion of any Debentures being redeemed in part.

          Any Debenture which is to be redeemed only in part shall be surren-
dered at the 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 make available for delivery to the Holder of
such Debenture without service charge, a new Debenture or Debentures, 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 Debenture so surrendered. Each Debenture shall be subject to partial
redemption only in the amount of [$1,000] or integral multiples thereof.

          The Debentures are not entitled to the benefit of any sinking or like
fund.

          Section 11.7 Mandatory Redemption.  Subject to Sections 5.2 and 5.13,
                       --------------------
upon (i) repayment at maturity or (ii) as a result of acceleration upon the
occurrence of an Event of Default, the Company shall redeem all the Outstanding
Debentures at a redemption price equal to 100% of the principal amount of such
Debentures plus any accrued and unpaid interest, including any Additional
Interest, to the date fixed for redemption.

          Section 11.8 Optional Redemption.  Except as set forth below, on and
                       -------------------
after __________, 20__ and subject to the next succeeding sentence, the Company
shall have the right, at any time and from time to time, to redeem the
Debentures, in whole or in part, upon notice given as set forth in Section 11.3
during the twelve-month periods beginning on ______ in each of the following
years at the indicated

                                      82
<PAGE>

Redemption Price (expressed as a percentage of the principal amount of the
Debentures being redeemed), together with any accrued but unpaid interest on the
portion being redeemed:

<TABLE>
<CAPTION>
Year       Redemption Price              Year              Redemption Price
----   (% of principal amount)           ----          (% of principal amount)
       -----------------------                         ------------------------
<S>    <C>                        <C>                  <C>
20__           _____%             20__ ..............         _____%
20__           _____%             20__ and thereafter         100.0%
20__           _____%
20__           _____%
20__           _____%
</TABLE>

          The Company may not redeem the Debentures in whole or in part unless
all accrued and unpaid interest has been paid in full on all outstanding
Debentures for all quarterly interest periods terminating on or prior to the
Redemption Date.

          Upon the occurrence of a Tax Event, the Company shall have the right,
upon not less than 30 nor more than 60 days' notice, to redeem the Debentures in
whole or in part, for cash upon the later of (i) 90 days following the
occurrence of such Tax Event or (ii) __________, 20__, at a Redemption Price
equal to the principal amount of such Debentures plus any accrued and unpaid
interest, including Additional Interest, to the date fixed for such redemption.

          [Section 11.9 Exchange of Trust Securities for Debentures.  (a) At any
                       -------------------------------------------
time, the Company shall have the right to terminate the Trust and cause the
Debentures to be distributed to the holders of the Preferred Securities in
liquidation of the Trust after satisfaction of liabilities to creditors of the
Trust as provided by applicable law.

               (b)  If a Special Event in respect of the Trust shall occur, the
Company shall give the Property Trustee notice of the same.  If a Special Event
in respect of the Trust shall occur and be continuing, the Trust Agreement
requires the Property Trustee to direct the Conversion Agent (as defined in the
Trust Agreement) to exchange all outstanding Trust Securities for the Debentures
having a principal amount equal to the aggregate liquidation amount of the Trust
Securities to be exchanged with accrued interest in an amount equal to any
unpaid distributions (including any Additional Amounts) on the Trust Securities
provided that, in the case of a Tax Event, the Company shall have the right to
--------
direct the Property Trustee

                                      83
<PAGE>

that less than all, or none of the Trust Securities be so exchanged (i) if and
for so long as the Company shall have elected to pay any Additional Sums such
that the net amounts received by holders of the Trust Securities not so
exchanged in respect of distributions are not reduced as a result of such Tax
Event, and shall not have revoked any such election or failed to make such
payments or (ii) if the Company shall instead elect to redeem the Debentures, in
whole or in part, in the manner set forth in Section 11.8.]

          Section 11.10  Purchases of Debentures.  Subject to applicable law
                         -----------------------
(including without limitation, United States federal securities law), the
Company or its subsidiaries or Affiliates may at any time and from time to time
purchase outstanding Debentures by tender, in the open market or by private
agreement.

                                      84
<PAGE>

                                  ARTICLE XII

                          SUBORDINATION OF DEBENTURES

          Section 12.1   Debentures Subordinate to Senior Debt.  The Company
                         -------------------------------------
covenants and agrees, and each Holder of a Debenture, by its acceptance thereof,
likewise covenants and agrees, that, to the extent and in the manner hereinafter
set forth in this Article, the payment of the principal of (and premium, if any)
and interest (including any Additional Interest) on each and all of the
Debentures are hereby expressly made subordinate and subject in right of payment
to the prior payment in full in cash of all amounts then due and payable in
respect of all Senior Debt (whether outstanding on the date hereof or hereafter
created, incurred, assumed or guaranteed), and that the subordination is for the
benefit of the holders of Senior Debt and that no payment on account of
principal of, premium, if any, or interest on the Debentures and no acquisition
of, or payment on account of any sinking fund for, the Debentures may be made
unless full payment of all amounts then due for principal, premium, if any, and
interest then due on all Senior Debt (by maturity, lapse of time, acceleration
or otherwise) has been made or duly provided for in cash or in a manner
satisfactory to the holders of such Senior Debt.

          Section 12.2   Payment Over of Proceeds Upon Dissolution, Etc.  Upon
                         -----------------------------------------------
any distribution of the Company's assets in connection with any dissolution,
winding up, liquidation or reorganization of the Company, whether voluntary or
involuntary, in bankruptcy, insolvency or receivership proceedings (each such
event, if any, herein sometimes referred to as a "Proceeding"), or upon an
assignment for the benefit of creditors or otherwise: (i) all Senior Debt
(including without limitation all interest accruing on or after the filing of
any petition in bankruptcy relating to the Company at the relevant contractual
rate, whether or not such claim for post-petition interest is allowed in such
proceeding) must be paid in full in cash before the Holders of the Debentures
are entitled to any payments or distributions of any kind or character
(including any payment or distribution which may be payable or deliverable by
reason of the payment of any other Debt of the Company (including the
Debentures) subordinated to the payment of the Debentures), and (ii) any payment
or distribution of the Company's assets of any kind or character, whether in
cash, securities or other property, which would otherwise (but for these
subordination provisions) be payable or deliverable in respect of the Debentures
shall be paid or delivered directly to the holders of such Senior Debt (or their
representative or trustee) in accordance with the priorities then existing among
such holders until all

                                      85
<PAGE>

Senior Debt shall have been paid in full in cash before any payment or
distribution is made to the Holders of the Debentures.

          In the event that notwithstanding the subordination provisions set
forth herein, any payment or distribution of assets of any kind or character is
made on the Debentures at a time when the respective payment is not permitted to
be made as a result of the subordination provisions described above and before
all Senior Debt is paid in full in cash, the Trustee or the Holders of the
Debentures receiving such payment will be required to pay over such payment or
distribution to the holders of such Senior Debt.

          For the purposes of this Article only, the words "any payment or
distribution of any kind or character" shall not be deemed to include shares of
stock of the Company as reorganized or readjusted, or securities of the Company
or any other Person provided for by a plan of reorganization or
readjustment which securities are subordinated in right of payment to all then
outstanding Senior Debt to substantially the same extent as the Debentures 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 sale of all or substantially all of its
properties and assets as an entirety to another Person upon the terms and
conditions set forth in Article 8 shall not be deemed a Proceeding 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 sale such properties
and assets as an entirety, as the case may be, shall, as a part of such
consolidation, merger, or sale comply with the conditions set forth in Article
Eight.

          Section 12.3   No Payment When Senior Debt in Default.  (a)  In the
                         --------------------------------------
event and during the continuation of any default in the payment of principal of
(or premium, if any) or interest on, or other amounts owing with respect to, any
Senior Debt, or in the event that any event of default with respect to any
Senior Debt shall have occurred and be continuing and shall have resulted in
such Senior Debt becoming or being able to be declared due and payable prior to
the date it would otherwise have become due and payable, unless and until such
event of default shall have been waived or shall have ceased to exist and such
acceleration shall have been rescinded or annulled, or (b) in the event any
judicial proceeding shall be pending with respect to any such default in payment
or such event or default, then, no payment or distribution of any kind or
character, whether in cash, properties or Debentures shall be made by the
Company on account of principal of (or premium, if any) or interest (including
any Additional Interest), if any, on the Debentures or on

                                      86
<PAGE>

account of the purchase or other acquisition of Debentures by the Company or any
Subsidiary other than payments made from funds on deposit pursuant to Section
4.1 or from funds on deposit for the redemption of Debentures for which notice
of redemption has been given and the Redemption Date has passed.

          The Company shall give prompt written notice to the Trustee of any
default of the type described in the preceding paragraph in respect of Senior
Debt; provided that no failure to give such a notice shall have any effect
whatsoever on the subordination provisions described herein.

          In the event that, notwithstanding the foregoing, the Company shall
make any payment to the Trustee or the Holder of the Debentures 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 as set forth in Section 12.9, 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 12.2 would be applicable.

          Section 12.4   Payment Permitted If No Default.  Nothing contained in
                         -------------------------------
this Article or elsewhere in this Indenture or in any of the Debentures shall
prevent (a) the Company, at any time except during the pendency of any
Proceeding referred to in Section 12.2 or under the conditions described in
Sections 12.3, from making payments at any time of principal of (and premium, if
any) or interest on the Debentures, or (b) except with respect to the payment
over provisions of this Article 12, the application by the Trustee of any money
deposited with it hereunder to the payment of or on account of the principal of
(and premium, if any) or interest (including any Additional Interest) on the
Debentures or the retention of such payment by the Holders, if, at the time of
such application by the Trustee, the Trustee did not have actual knowledge that
such payment would have been prohibited by the provisions of this Article.

          Section 12.5   Subrogation to Rights of Holders of Senior Debt.
                         -----------------------------------------------
Subject to the payment in full in cash of all Senior Debt, or the provision for
such payment in cash or cash equivalents or otherwise in a manner satisfactory
to the holders of Senior Debt, the Holders of the Debentures shall be subrogated
to the extent of the payments or distributions made to the holders of such
Senior Debt pursuant to the provisions of this Article (equally and ratably with
the holders of all

                                      87
<PAGE>

indebtedness of the Company which by its express terms is subordinated to Senior
Debt of the Company to substantially the same extent as the Debentures are
Subordinated to the Senior Debt and is entitled to like rights of subrogation
by reason of any payments or distributions made to holders of such Senior Debt)
to the rights of the holders of such Senior Debt to receive payments and
distributions of cash, property and securities applicable to the Senior Debt
until the principal of (and premium, if any) and interest on the Debentures
shall be paid in full. For purposes of such subrogation, no payments or
distributions to the holders of the Senior Debt of any cash, property or
securities to which the Holders of the Debentures or the Trustee would be
entitled except for the provisions of this Article, and no payments pursuant to
the provisions of this Article to the holders of Senior Debt by Holders of the
Debentures or the Trustee, shall, as among the Company, its creditors other than
holders of Senior Debt, and the Holders of the Debentures, be deemed to be a
payment or distribution by the Company to or on account of the Senior Debt.

          Section 12.6   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 the Debentures on the one hand
and the holders of Senior Debt on the other hand.  Nothing contained in this
Article or elsewhere in this Indenture or in the Debentures is intended to or
shall (a) impair, as between the Company and the Holders of the Debentures, the
obligations of the Company, which are absolute and unconditional, to pay to the
Holders of the Debentures the principal of (and premium, if any) and interest
(including any Additional Interest) on the Debentures as and when the same shall
become due and payable in accordance with their terms, or (b) affect the
relative rights against the Company of the Holders of the Debentures and
creditors of the Company other than their rights in relation to the holders of
Senior Debt, or (c) prevent the Trustee or the Holder of any Debenture from
exercising all remedies otherwise permitted by applicable law upon default under
this Indenture including, without limitation, filing and voting claims in any
Proceeding, subject to the rights, if any, under this Article of the holders of
Senior Debt to receive cash, property and securities otherwise payable or
deliverable to the Trustee or such Holder.

          Section 12.7   Trustee to Effectuate Subordination.  Each Holder of a
                         -----------------------------------
Debenture by his or her acceptance thereof authorizes and directs the Trustee on
his or her behalf to take such action as may be necessary or appropriate to
acknowledge or effectuate the subordination provided in this Article and
appoints the Trustee his or her attorney-in-fact for any and all such purposes.

                                      88
<PAGE>

          Section 12.8   No Waiver of Subordination Provisions.  No right of any
                         -------------------------------------
present or future holder of any Senior Debt 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 that any such holder may have or be otherwise charged with.

          Section 12.9   Notice to Trustee.  The Company shall give prompt
                         -----------------
written notice to 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 the
Debentures. 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 the Debentures, unless and until the Trustee
shall have received written notice thereof from the Company or a person
representing itself as a holder of Senior Debt or from any trustee, agent or
representative therefor (whether or not the facts contained in such notice are
true).

          Section 12.10  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 Article
6, and the Holders of the Debentures shall be entitled to rely upon any order or
decree entered by any court of competent jurisdiction in which a Proceeding is
pending, or a 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 Debentures, for the purpose of ascertaining the Persons entitled to
participate in such payment or distribution, the holders of the Senior Debt and
other indebtedness of the Company, the amount thereof or payable thereon, the
amount or amounts paid or distributed thereon and all other facts pertinent
thereto or to this Article.

          Section 12.11  Trustee Not Fiduciary for Holders of Senior Debt. With
                         ------------------------------------------------
respect to the holders of the Senior Debt of the Company, the Trustee under
takes to perform or observe only such of its obligations and covenants as are
set forth in this Article 12, and no implied covenants or obligations with
respect to the holders of such Senior Debt shall be read into this Indenture
against Chase Manhattan Trust Company, National Association and/or the Trustee.
Chase Manhattan Trust Company, National Association and/or the Trustee shall not
be deemed to owe any fiduciary duty to the holders of such Senior Debt and,
subject to the

                                      89
<PAGE>

provisions of Section 6.3, neither the Trustee (nor Chase Manhattan Trust
Company, National Association) shall be liable to the holder of any Senior Debt
if it shall pay over or deliver to Holders, the Company, or any other Person,
money or assets to which any holder of such Senior Debt shall be entitled to by
virtue of this Article 12 or otherwise.

          Section 12.12  Rights of Trustee as Holder of Senior Debt;
                         -------------------------------------------
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 Debt which may at any time be held by it, to the same extent as any
other holder of Senior Debt, and, subject to the requirements of the Trust
Indenture Act, nothing in this Indenture shall deprive the Trustee of any of its
rights as such holder.

          Section 12.13  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
intent and purposes as if such Paying Agent were named in this Article in
addition to or in place of the Trustee.

          Section 12.14  Certain Conversions or Exchanges Deemed Payment. For
                         -----------------------------------------------
the purpose of this Article only, (a) the issuance and delivery of junior
securities upon conversion or exchange of Debentures shall not be deemed to
constitute a payment or distribution on account of the principal of (or premium,
if any) or interest (including any Additional Interest) on the Debentures or on
account of the purchase or other acquisition of Debentures, and (b) the payment,
issuance or delivery of cash (including any payments for fractional shares),
property or securities (other than junior securities) upon conversion or
exchange of a Debenture shall be deemed to constitute payment on account of the
principal of such Debenture.  For the purpose of this Section, the term "junior
securities" means (i) shares of any stock of any class of the Company and (ii)
securities of the Company which are subordinated in right of payment to all
Senior Debt 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
Debentures are so subordinated as provided in this Article.

          Section 12.15  Trust Moneys Not Subordinated.  Notwithstanding
                         -----------------------------
anything contained herein to the contrary (provided that at the time deposited,
                                           --------
such deposit did not violate any then outstanding Senior Debt), payments from
money or the proceeds of Government Obligations held in trust under Article 4 by
the Trustee

                                      90
<PAGE>

for the payment of principal of and interest on the Debentures shall not be
subordinated to the prior payment of any Senior Debt or subject to the
restrictions set forth in this Article 12, and none of the Holders shall be
obligated to pay over any such amount to the Company or any holder of Senior
Debt of the Company or any other creditor of the Company.


                                  ARTICLE XII

                            [CONVERSION OF DEBENTURES

          Section 13.1   Conversion Rights.  Subject to and upon compliance with
                         -----------------
the provisions of this Article, the Debentures are convertible, at the option of
the Holder, at any time prior to redemption or Maturity, into fully paid and
nonassessable shares of Common Stock of the Company at an initial conversion
rate of ______ shares of Common Stock for each $[1,000] in aggregate principal
amount of Debentures (equal to a conversion price of $______ per share of Common
Stock), subject to adjustment as described in this Article 13 (as adjusted the
"Conversion Price"). A Holder of Debentures may convert any portion of the
principal amount of the Debentures into that number of fully paid and
nonassessable shares of Common Stock (calculated as to each conversion to the
nearest 1/100th of a share) obtained by dividing the principal amount of the
Debentures to be converted by the Conversion Price. In case a Debenture or
portion thereof is called for redemption, such conversion right in respect of
the Debenture or portion so called shall expire at the close of business on the
Business Day immediately preceding the corresponding Redemption Date, unless the
Company defaults in making the payment due upon redemption.

          Section 13.2   Conversion Procedures.  (a)  In order to convert all or
                         ---------------------
a portion of the Debentures, the Holder thereof shall deliver to the [Property
Trustee, as] conversion agent or to such other agent appointed for such purposes
(the "Conversion Agent") an irrevocable Notice of Conversion setting forth the
principal amount of Debentures to be converted, together with the name or names,
if other than the Holder, in which the shares of Common Stock should be issued
upon conversion and, if such Debentures are definitive Debentures, surrender to
the Conversion Agent the Debentures to be converted, duly endorsed or assigned
to the Company or in blank. [In addition, a holder of Preferred Securities may
exercise its right under the Trust Agreement to convert such Preferred
Securities into Common Stock by delivering to the Conversion Agent an
irrevocable Notice of Conversion setting forth the information called for by the
preceding sentence and directing the Conversion

                                      91
<PAGE>

Agent (i) to exchange such Preferred Security for a portion of the Debentures
held by the Trust (at an exchange rate of $50 principal amount of Debentures for
each Preferred Security) and (ii) to immediately convert such Debentures, on
behalf of such holder, into Common Stock of the Company pursuant to this Article
13 and, if such Preferred Securities are in definitive form, surrendering such
Preferred Securities, duly endorsed or assigned to the Company or in blank. So
long as any Preferred Securities are outstanding, the Trust shall not convert
any Debentures except pursuant to a Notice of Conversion delivered to the
Conversion Agent by a holder of Preferred Securities.]

          If a Notice of Conversion is delivered on or after the Regular Record
Date and prior to the subsequent Interest Payment Date, the Holder of record on
the Regular Record Date will be entitled to receive the interest paid on the
subsequent Interest Payment Date on the portion of Debentures to be converted
notwithstanding the conversion thereof prior to such Interest Payment Date.
Except as otherwise provided in the immediately preceding sentence, in the case
of any Debenture which is converted, interest whose Stated Maturity is on or
after the date of conversion of such Debenture shall not be payable, and the
Company shall not make nor be required to make any other payment, adjustment or
allowance with respect to accrued but unpaid interest on the Debentures being
converted, which shall be deemed to be paid in full.  Each conversion shall be
deemed to have been effected immediately prior to the close of business on the
day on which the Notice of Conversion was received (the "Conversion Date") by
the Conversion Agent from the Holder or from a holder of the Preferred
Securities effecting a conversion thereof pursuant to its conversion rights
under the Trust Agreement, as the case may be.  The Person or Persons entitled
to receive the Common Stock issuable upon such conversion shall be treated for
all purposes as the record holder or holders of such Common Stock as of the
Conversion Date and such Person or Persons will cease to be a record Holder or
record Holders of the Debentures on that date.  As promptly as practicable on or
after the Conversion Date, the Company shall issue and deliver at the office of
the Conversion Agent, unless otherwise directed by the Holder or Holders in the
Notice of Conversion, a certificate or certificates for the number of full
shares of Common Stock issuable upon such conversion, together with the cash
payment, if any, in lieu of any fraction of any share to the Person or Persons
entitled to receive the same. The Conversion Agent shall deliver such
certificate or certificates to such Person or Persons.

          (b) The Company's delivery upon conversion of the fixed number of
shares of Common Stock into which the Debentures are convertible

                                      92
<PAGE>

(together with the cash payment, if any, in lieu of fractional shares) shall be
deemed to satisfy the Company's obligation to pay the principal amount at
Maturity of the portion of Debentures so converted and any unpaid interest
(including Additional Interest) accrued on such Debentures at the time of such
conversion.

          (c) No fractional shares of Common Stock will be issued as a result of
conversion, but in lieu thereof, the Company shall pay to the Conversion Agent a
cash adjustment in an amount equal to the same fraction of the Current Market
Price with respect to such fractional interest on the date on which the
Debentures or Preferred Securities, as the case may be, were duly surrendered to
the Conversion Agent for conversion, and the Conversion Agent in turn will make
such payment, if any, to the Holder of the Debentures or the holder of the
Preferred Securities so converted.

          (d) In the event of the conversion of any Debenture in part only, a
new Debenture or Debentures for the unconverted portion thereof will be issued
in the name of the Holder thereof upon the cancellation of the Debenture
converted in part in accordance with Section 3.5.

          (e) In effecting the conversion transactions described in this
Section, the Conversion Agent is acting [as agent of the holders of Preferred
Secuities (in the exchange of Preferred Securities for Debentures) and] as agent
of the Holders of Debentures (in the conversion of Debentures into Common
Stock)[, as the case may be,] directing it to effect such conversion
transactions. The Conversion Agent is hereby authorized [(i) to exchange
Debentures held by the Trust from time to time for Preferred Securities in
connection with the conversion of such Preferred Securities in accordance with
this Article 13 and (ii) [to convert all or a portion of the Debentures into
Common Stock and thereupon to deliver such shares of Common Stock in accordance
with the provisions of this Article 13 [and to deliver to the Trust a new
Debenture or Debentures for any resulting unconverted principal amount.]

          (f) The Company shall at all times reserve and keep available out of
its authorized and unissued Common Stock, solely for issuance upon the
conversion of the Debentures, such number of shares of Common Stock as shall
from time to time be issuable upon the conversion of all the Debentures then
outstanding.  Notwithstanding the foregoing, the Company shall be entitled to
deliver upon conversion of Debentures shares of Common Stock reacquired and held
in the treasury of the Company (in lieu of the issuance of authorized and
unissued shares of Common Stock) so long as any such treasury shares are free
and clear of all liens,

                                      93
<PAGE>

charges, security interests or encumbrances. Whenever the Company issues shares
of Common Stock upon conversion of Debentures and the Company has in effect at
such time a share purchase rights agreement under which holders of Common Stock
are issued rights ("Rights") entitling the holders under certain circumstances
to purchase an additional share or shares of stock, the Company will issue,
together with each such share of Common Stock, such number of Rights (which
number may be a fraction) as shall at that time be issuable with a share of
Common Stock pursuant to such share purchase rights agreement. Any shares of
Common Stock issued upon conversion of the Debentures shall be duly authorized,
validly issued and fully paid and nonassessable. The Conversion Agent shall
deliver the shares of Common Stock received upon conversion of the Debentures to
the converting Holder free and clear of all liens, charges, security interests
and encumbrances, except for United States withholding taxes. The Company shall
use its best efforts to obtain and keep in force such governmental or regulatory
permits or other authorizations as may be required by law, and shall comply with
all applicable requirements as to registration or qualification of the Common
Stock (and all requirements to list the Common Stock issuable upon conversion of
Debentures that are at the time applicable), in order to enable the Company to
lawfully issue Common Stock upon conversion of the Debentures and to lawfully
deliver the Common Stock to each Holder upon conversion of the Debentures.

          (g) The Company will pay any and all taxes that may be payable in
respect of the issue or delivery of shares of Common Stock on conversion of
Debentures.  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 Common Stock in a name other than that in which the Debentures so
converted were registered, and no such issue or delivery shall be made unless
and until the Person requesting such issue has paid to the Conversion Agent the
amount of any such tax, or has established to the satisfaction of the Conversion
Agent that such tax has been paid.

          (h) Nothing in this Article 13 shall limit the requirement of the
Company to withhold taxes pursuant to the terms of the Debentures or as set
forth in this Agreement or otherwise require the Trustee or the Company to pay
any amounts on account of such withholdings.

          Section 13.3   Conversion Price Adjustments.  The conversion price
                         ----------------------------
shall be subject to adjustment (without duplication) from time to time as
follows:

                                      94
<PAGE>

          (a) In case the Company shall, while any of the Debentures are
outstanding, (i) pay a dividend or make a distribution with respect to its
Common Stock in shares of Common Stock, (ii) subdivide its outstanding shares of
Common Stock, (iii) combine its outstanding shares of Common Stock into a
smaller number of shares or (iv) issue by reclassification of its shares of
Common Stock any shares of capital stock of the Company, the conversion
privilege and the Conversion Price in effect immediately prior to such action
shall be adjusted so that the Holder of any Debentures thereafter surrendered
for conversion shall be entitled to receive the number of shares of capital
stock of the Company which he would have owned immediately following such action
had such Debentures been converted immediately prior thereto.  An adjustment
made pursuant to this subsection (a) shall become effective immediately after
the record date in the case of a dividend or other distribution and shall
become effective immediately after the effective date in case of a subdivision,
combination or reclassification (or immediately after the record date if a
record date shall have been established for such event).  If, as a result of an
adjustment made pursuant to this subsection (a), the Holder of any Debenture
thereafter surrendered for conversion shall become entitled to receive shares of
two or more classes or series of capital stock of the Company, the Board of
Directors (whose determination shall be conclusive and shall be described in a
Board Resolution filed with the Trustee) shall determine the allocation of the
adjusted Conversion Price between or among shares of such classes or series of
capital stock.  In the event that such dividend, distribution, subdivision,
combination or issuance is not so paid or made, the Conversion Price shall again
be adjusted to be the Conversion Price which would then be in effect if such
record date had not been fixed.

          (b) In case the Company shall, while any of the Debentures are
Outstanding, issue rights or warrants to all holders of its Common Stock
entitling them (for a period expiring within 45 days after the record date
mentioned below) to subscribe for or purchase shares of Common Stock at a price
per share less than the Current Market Price per share of Common Stock on the
record date mentioned below, the Conversion Price for the Debentures shall be
adjusted so that the same shall equal the price determined by multiplying the
Conversion Price in effect immediately prior to the date of issuance of such
rights or warrants by a fraction, the numerator of which shall be the number of
shares of Common Stock outstanding on the date of issuance of such rights or
warrants plus the number of shares which the aggregate offering price of the
total number of shares so offered for subscription or purchase would purchase at
such Current Market Price, and the denominator of which shall be the number of
shares of Common Stock outstanding on the date of issuance of such rights or
warrants plus the number of additional shares of Common

                                      95
<PAGE>

Stock offered for subscription or purchase. Such adjustment shall become
effective immediately after the record date for the determination of
stockholders entitled to receive such rights or warrants. For the purposes of
this subsection, the number of shares of Common Stock at any time outstanding
shall not include shares held in the treasury of the Company. The Company shall
not issue any rights or warrants in respect of shares of Common Stock held in
the treasury of the Company. In case any rights or warrants referred to in this
subsection in respect of which an adjustment shall have been made shall expire
unexercised within 45 days after the same shall have been distributed or issued
by the Company, the Conversion Price shall be readjusted at the time of such
expiration to the Conversion Price that would have been in effect if no
adjustment had been made on account of the distribution or issuance of such
expired rights or warrants.

          (c) Subject to the last sentence of this subparagraph, in case the
Company shall, by dividend or otherwise, distribute to all holders of its Common
Stock evidences of its indebtedness, shares of any class or series of capital
stock, cash or assets (including securities, but excluding any rights or
warrants referred to in subparagraph (b), any dividend or distribution paid
exclusively in cash and any dividend or distribution referred to in subparagraph
(a) of this Section 13.3), the Conversion Price shall be reduced so that the
same shall equal the price determined by multiplying the Conversion Price in
effect immediately prior to the effectiveness of the Conversion Price reduction
contemplated by this subparagraph (c) by a fraction, the numerator of which
shall be the Current Market Price per share of the Common Stock on the date
fixed for the payment of such distribution (the "Reference Date") less the
fair market value (as determined in good faith by the Board of Directors, whose
determination shall be conclusive and described in a resolution of the Board of
Directors), on the Reference Date, of the portion of the evidences of
indebtedness, shares of capital stock, cash and assets so distributed applicable
to one share of Common Stock, and the denominator of which shall be such Current
Market Price per share of the Common Stock, such reduction to become effective
immediately prior to the opening of business on the day following the
Reference Date.  In the event that such dividend or distribution is not so paid
or made, the Conversion Price shall again be adjusted to be the Conversion Price
which would then be in effect if such dividend or distribution had not occurred.
For purposes of this subparagraph (c), any dividend or distribution that
includes shares of Common Stock or rights or warrants to subscribe for or
purchase shares of Common Stock shall be deemed instead to be (i) a dividend or
distribution of the evidences of indebtedness, shares of capital stock, cash or
assets other than such shares of Common Stock or such rights or warrants (making
any Conversion Price reduction required by this

                                      96
<PAGE>

subparagraph (c)) immediately followed by (ii) a dividend or distribution of
such shares of Common Stock or such rights or warrants (making any further
conversion price reduction required by subparagraph (a) or (b)), except (A) the
Reference Date of such dividend or distribution as defined in this subparagraph
shall be substituted as (x) "the record date in the case of a dividend or other
distribution," and (y) "the record date for the determination of stockholders
entitled to receive such rights or warrants" and (z) "the date fixed for such
determination" within the meaning of subparagraphs (a) and (b) and (B) any
shares of Common Stock included in such dividend or distribution shall not be
deemed outstanding for purposes of computing any adjustment of the conversion
price in subparagraph (a).

          (d) In case the Company shall pay or make a dividend or other
distribution on its Common Stock exclusively in cash (excluding all cash
dividends, if the annualized amount thereof per share of Common Stock does not
exceed 12.5% of the Current Market Price per share of the Common Stock on the
trading day immediately preceding the date of declaration of such dividend), the
Conversion Price shall be reduced so that the same shall equal the price
determined by multiplying the Conversion Price in effect immediately prior to
the effectiveness of the Conversion Price reduction contemplated by this
subparagraph (d) by a fraction, the numerator of which shall be the Current
Market Price per share of the Common Stock on the date fixed for the payment of
such distribution less the amount of cash so distributed (excluding that portion
of such distribution that does not exceed 12.5% of the Current Market Price per
share, determined as provided above) applicable to one share of Common Stock and
the denominator of which shall be such Current Market Price per share of the
Common Stock, such reduction to become effective immediately prior to the
opening of business on the day following the date fixed for the payment of such
distribution; provided, however, that in the event the portion of the cash so
              --------  -------
distributed applicable to one share of Common Stock is equal to or greater than
the Current Market Price per share of the Common Stock on the record date
mentioned above (excluding that portion of such distribution that does not
exceed 12.5% of the Current Market Price per share, determined as provided
above), in lieu of the foregoing adjustment, adequate provision shall be made so
that each Holder of shares of Debentures shall have the right to receive upon
conversion the amount of cash such Holder would have received had such Holder
converted each share of the Debentures immediately prior to the record date for
the distribution of the cash (less that portion of such distribution that does
not exceed 12.5% of the Current Market Price per share, determined as provided
above).  In the event that such dividend or distribution is not so paid or made,
the Conversion Price

                                      97
<PAGE>

shall again be adjusted to be the conversion price which would then be in effect
if such record date had not been fixed.

          (e) In case a tender or exchange offer (other than an odd-lot offer)
made by the Company or any Subsidiary of the Company for all or any portion of
the Common Stock shall expire and such tender or exchange offer shall involve
the payment by the Company or such Subsidiary of consideration per share of
Common Stock having a fair market value (as determined in good faith by the
Board of Directors, whose determination shall be conclusive and described in a
resolution of the Board of Directors) at the last time (the "Expiration Time")
tenders or exchanges may be made pursuant to such tender or exchange offer (as
it shall have been amended) that exceeds 110% of the Current Market Price per
share of the Common Stock on the trading day next succeeding the Expiration
Time, the Conversion Price shall be reduced so that the same shall equal the
price determined by multiplying the Conversion Price in effect immediately prior
to the effectiveness of the Conversion Price reduction contemplated by this
subparagraph (e) by a fraction, the numerator of which shall be the number of
shares of Common Stock outstanding (including any tendered or exchanged shares)
at the Expiration Time (including the Purchased Shares) (as defined below)
multiplied by the Current Market Price per share of the Common Stock on the
Trading Day next succeeding the Expiration Time and the denominator of which
shall be the sum of (x) the fair market value (deter  mined as aforesaid) of the
aggregate consideration payable to stockholders based on the acceptance (up to
any maximum specified in the terms of the tender or exchange offer) of all
shares validly tendered or exchanged and not withdrawn as of the Expiration Time
(the shares deemed so accepted, up to any such maximum, being referred to as the
"Purchased Shares") (excluding that portion of such consideration that does not
exceed 110% of the Current Market Price per share) and (y) the product of the
number of shares of Common Stock outstanding (less any Purchased Shares) at the
Expiration Time and the Current Market Price per share of the Common Stock on
the trading day next succeeding the Expiration Time, such reduction to become
effective immediately prior to the opening of business on the day following the
Expiration Time.  In the event that such tender or exchange offer is not so
made, the Conversion Price shall again be adjusted to be the Conversion Price
which would then be in effect if such record date had not been fixed.

          (f) If the distribution date for the Rights of the Company provided in
a share purchase rights agreement occurs prior to the Conversion Date, and a
Holder of the Debentures who converts such Debentures after such distribution
date is not entitled to receive

                                      98
<PAGE>

the Rights that would otherwise be attached (but for the date of conversion) to
the shares of Common Stock received upon such conversion, then an adjustment
shall be made to the Conversion Price pursuant to clause (ii) of Section 13.4(a)
as if the Rights were being distributed to the common stockholders of the
Company immediately prior to such conversion. If such an adjustment is made and
the Rights are later redeemed, invalidated or terminated, then a corresponding
reversing adjustment shall be made to the Conversion Price, on an equitable
basis, to take account of such event.

          (g) The Company shall have the right to reduce from time to time the
Conversion Price by any amount selected by the Company for any period of at
least 30 days, provided, that the Company shall give at least 15 days' notice of
               --------
such reduction to the Trustee [and the Property Trustee]. The Company may, at
its option, make such reductions in the Conversion Price, in addition to those
set forth above in Section 13.4(a), as the Board of Directors deems advisable to
avoid or diminish any income tax to holders of Common Stock resulting from any
dividend or distribution of stock (or rights to acquire stock) or from any event
treated as such for income tax purposes. No adjustment of the Conversion Price
will be made upon the issuance of any shares of Common Stock (or securities
convertible into or exercisable or exchangeable for Common Stock) except as
specifically described above including pursuant to any present or future plan
providing for the reinvestment of dividends or interest payable on securities of
the Company and the investment of additional optional amounts in shares of
Common Stock under any such plan, or the issuance of any shares of Common Stock
or options or rights to purchase such shares pursuant to any present or future
employee benefit plan or program of the Company or pursuant to any option,
warrant, right, or exercisable, exchangeable or convertible security which does
not constitute an issuance to all holders of Common Stock of rights or warrants
entitling holders of such rights or warrants to subscribe for or purchase Common
Stock at less than the Current Market Price. No adjustment in the Conversion
Price will be required unless such adjustment would require an increase or
decrease of at least 1% of the Conversion Price, but any adjustment that would
otherwise be required to be made shall be carried forward and taken into account
in a subsequent adjustment.

          (h) If any action would require adjustment of the Conversion Price
pursuant to more than one of the provisions described above, only one adjustment
shall be made and such adjustment shall be the amount of adjustment that has the
highest absolute value to the Holder of the Debentures.

                                      99
<PAGE>

          Section 13.4   Fundamental Change.  (a)  In the event that the Company
                         ------------------
is a party to any transaction (including, without limitation, a merger other
than a merger that does not result in a reclassification, conversion, exchange
or cancellation of Common Stock), consolidation, sale of all or substantially
all of the assets of the Company, recapitalization or reclassification of Common
Stock (other than a reclassification or recapitalization to which Section
13.3(a) is applicable) or any compulsory share exchange (each of the foregoing
being referred to as a "Transaction"), in each case, as a result of which
shares of Common Stock shall be converted into the right to receive, or shall be
exchanged for, (i) in the case of any Transaction other than a Transaction
involving a Common Stock Fundamental Change (and subject to funds being legally
available for such purpose under applicable law at the time of such conversion),
securities, cash or other property, each Debenture shall thereafter be
convertible into the kind and, in the case of a Transaction which does not
involve a Fundamental Change, amount of securities, cash and other property
receivable upon the consummation of such Transaction by a holder of that number
of shares of Common Stock into which a Debenture was convertible immediately
prior to such Transaction, or (ii) in the case of a Transaction involving a
Common Stock Fundamental Change, common stock, each Debenture shall thereafter
be convertible (in the manner described herein) into common stock of the kind
received by holders of Common Stock (but in each case after giving effect to any
adjustment discussed in paragraphs (b) and (c) relating to a Fundamental Change
if such Transaction constitutes a Fundamental Change). The holders of
Debentures or Preferred Securities will have no voting rights with respect to
any Transaction described in this section.

               (b)  If any Fundamental Change occurs, then the Conversion Price
in effect will be adjusted immediately after such Fundamental Change as
described in paragraph (c) below. In addition, in the event of a Common Stock
Fundamental Change, each Debenture shall be convertible solely into common stock
of the kind received by holders of Common Stock as a result of such Common Stock
Fundamental Change.

               (c)  The Conversion Price in the case of any Transaction
involving a Fundamental Change will be adjusted immediately after such
Fundamental Change:

                    (1)  in the case of a Non-Stock Fundamental Change, the
          Conversion Price of the Debentures will thereupon become the lower of
          (A) the Conversion Price in effect immediately prior to such Non-Stock
          Fundamental Change, but after giving effect

                                      100
<PAGE>

          to any other prior adjustments, and (B) the result obtained by multi
          plying the greater of the Applicable Price or the then applicable
          Reference Market Price by a fraction, the numerator of which will be
          $50 and the denominator of which will be (x) the amount of the
          redemption price for each $50 aggregate principal amount of Debentures
          if the redemption date were the date of such Non-Stock Fundamental
          Change (or, for the period commencing on the first date of original
          issuance of the Debentures and through __________, 20__, and the
          twelve-month periods commencing __________, 20__ and __________, 20__,
          the product of _____%, _____% and ______%, respectively, multiplied by
          $50) plus (y) any then-accrued and unpaid interest on the Debentures;
          and

                    (2)  in the case of a Common Stock Fundamental Change, the
          Conversion Price of the Debentures in effect immediately prior to such
          Common Stock Fundamental Change, but after giving effect to any other
          prior adjustments, will thereupon be adjusted by multiplying such
          Conversion Price by a fraction, the numerator of which will be the
          Purchaser Stock Price and the denominator will be the Applicable
          Price; provided, however, that in the event of a Common Stock
          Fundamental Change in which (A) 100% of the value of the consideration
          received by a holder of Common Stock is common stock of the successor,
          acquiror, or other third party (and cash, if any, is paid only with
          respect to any fractional interests in such common stock resulting
          from such Common Stock Fundamental Change) and (B) all of the Common
          Stock will have been exchanged for, converted into, or acquired for
          common stock (and cash with respect to fractional interests) of the
          successor, acquiror, or other third party, the Conversion Price of the
          Debentures in effect immediately prior to such Common Stock
          Fundamental Change will thereupon be adjusted by multiplying such
          Conversion Price by a fraction, the numerator of which will be one and
          the denominator of which will be the number of shares of common stock
          of the successor, acquiror, or other third party received by a holder
          of one share of Common Stock as a result of such Common Stock
          Fundamental Change.

          Section 13.5   Notice of Adjustments of Conversion Price.  Whenever
                         -----------------------------------------
the Conversion Price is adjusted as herein provided:

                                      101
<PAGE>

               (a)  the Company shall compute the adjusted Conversion Price and
shall prepare a certificate signed by the Chief Financial Officer or the
Treasurer of the Company 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 with the Trustee, the Conversion Agent and
the transfer agent for the Preferred Securities and the Debentures; and

               (b)  a notice stating the Conversion Price has been adjusted and
setting forth the adjusted Conversion Price shall as soon as practicable be
mailed by the Company to all record holders of Preferred Securities and the
Debentures at their last addresses as they appear upon the stock transfer books
of the Company and the Trust and the Securities Registrar.

          Section 13.6   Prior Notice of Certain Events.
                         ------------------------------

          In case:

                         (i)   the Company shall (A) declare any dividend (or
     any other distribution) on its Common Stock, other than (x) a dividend
     payable in shares of Common Stock or (y) a dividend payable in cash that
     would not require an adjustment pursuant to Section 13.4(c) or (d) or (B)
     authorize a tender or exchange offer that would require an adjustment
     pursuant to Section 13.4(e);

                         (ii)  the Company shall authorize the granting to all
     holders of Common Stock of rights or warrants to subscribe for or purchase
     any shares of stock of any class or series or of any other rights or
     warrants;

                         (iii) of any reclassification of Common Stock (other
     than a subdivision or combination of the outstanding Common Stock, or a
     change in par value, or from par value to no par value, or from no par
     value to par value), or of any consolidation or merger to which the Company
     is a party and for which approval of stockholders of the Company shall be
     required, or of the sale or transfer of all or substantially all of the
     assets of the Company or of any compulsory share exchange whereby the
     Common Stock is converted into other securities, cash or other property;
     or

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

                                      102
<PAGE>

then the Company shall [(A) if any Preferred Securities are outstanding under
the Trust Agreement, cause to be filed with the transfer agent for the Preferred
Securities, and shall cause to be mailed to the holders of record of the
Preferred Securities, at their last addresses as they shall appear upon the
stock transfer books of the Trust or (B)] cause to be mailed to all Holders at
their last addresses as they shall appear in the Security Register, at least 15
days prior to the applicable record or effective date hereinafter specified, a
notice stating (x) the date on which a record (if any) is to be taken for the
purpose of such dividend, distribution, rights 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 or warrants are to be
determined or (y) the date on which such reclassification, consolidation,
merger, sale, transfer, share exchange, 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, sale, transfer, share exchange,
dissolution, liquidation or winding up (but no failure to mail such notice or
any defect therein or in the mailing thereof shall affect the validity of the
corporate action required to be specified in such notice).

          Section 13.7   Dividend or Interest Reinvestment Plans.
                         ---------------------------------------
Notwithstanding anything to the contrary in this Article 13, the issuance of any
shares of Common Stock pursuant to any plan providing for the reinvestment of
dividends or interest payable on securities of the Company and the investment of
additional optional amounts in shares of Common Stock under any such plan, and
the issuance of any shares of Common Stock or options or rights to purchase such
shares pursuant to any employee benefit plan or program of the Company or
pursuant to any option, warrant, right or exercisable, exchangeable or
convertible security outstanding as of the date the Debentures were first
issued, shall not be deemed to constitute an issuance of Common Stock or
exercisable, exchangeable or convertible securities by the Company to which any
of the adjustment provisions described above applies. There shall also be no
adjustment of the Conversion Price in case of the issuance of any stock (or
securities convertible into or exchangeable for stock) of the Company except as
specifically described in this Article 13.

          Section 13.8   Certain Additional Rights.  In case the Company shall,
                         -------------------------
by dividend or otherwise, declare or make a distribution on its Common Stock
referred to in Section 13.4(c) or 13.4(d) (including, without limitation,
dividends or distributions referred to in the last sentence of Section 13.4(c)),
the Holders of the

                                      103
<PAGE>

Debentures, upon the conversion thereof subsequent to the close of business on
the date fixed for the determination of stockholders entitled to receive such
distribution and prior to the effectiveness of the Conversion Price adjustment
in respect of such distribution, shall also be entitled to receive for each
share of Common Stock into which the Debentures are converted, the portion of
the shares of Common Stock, rights, warrants, evidences of indebtedness, shares
of capital stock, cash and assets so distributed applicable to one share of
Common Stock; provided, however, that, at the election of the Company (whose
              --------  -------
election shall be evidenced by a resolution of the Board of Directors) with
respect to all Holders so converting, the Company may, in lieu of distributing
to such Holder any portion of such distribution not consisting of cash or
securities of the Company, pay such Holder an amount in cash equal to the fair
market value thereof (as determined in good faith by the Board of Directors,
whose determination shall be conclusive and described in a resolution of the
Board of Directors). If any conversion of Debentures described in the
immediately preceding sentence occurs prior to the payment date for a
distribution to holders of Common Stock which the Holder of Debentures so
converted is entitled to receive in accordance with the immediately preceding
sentence, the Company may elect (such election to be evidenced by a resolution
of the Board of Directors) to distribute to such Holder a due bill for the
shares of Common Stock, rights, warrants, evidences of indebtedness, shares of
capital stock, cash or assets to which such Holder is so entitled, provided,
                                                                   --------
that such due bill (i) meets any applicable requirements of the principal
national securities exchange or other market on which the Common Stock is then
traded and (ii) requires payment or delivery of such shares of Common Stock,
rights, warrants, evidences of indebtedness, shares of capital stock, cash or
assets no later than the date of payment or delivery thereof to holders of
shares of Common Stock receiving such distribution.

          Section 13.9   Trustee Not Responsible for Determining Conversion
                         --------------------------------------------------
Price or Adjustments.  Neither the Trustee nor any Conversion Agent shall at any
--------------------
time be under any duty or responsibility to any Holder of any Debenture [or to
any holder of a Preferred Security] 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, or herein or in any supplemental indenture 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 of account) 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 Debenture; and neither
the Trustee nor any Conversion Agent makes any representation with respect
thereto.  Neither the Trustee nor any

                                      104
<PAGE>

Conversion Agent shall be responsible for any failure of the Company to make any
cash payment or to issue, transfer or deliver any shares of Common Stock or
stock certificates or other securities or property upon the surrender of any
Debenture for the purpose of conversion, or, except as expressly herein
provided, to comply with this Article 13.]

                              *     *     *     *

          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.

                                      105
<PAGE>

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


                                      ALCOA INC.


                                      By:_____________________________________


                                      CHASE MANHATTAN TRUST COMPANY, National
                                      Association as Trustee


                                      By:_____________________________________


                                      106
<PAGE>

                                  [  Annex A
                                     -------

                            Declaration of Trust ]
                            --------------------
<PAGE>

                                   [ Annex B
                                     -------

                    Amended and Restated Trust Agreement ]
                    ------------------------------------
<PAGE>

                                   [ Annex C
                                     -------

                             Guarantee Agreement ]
                             -------------------