<PAGE>   1

                                                                    Exhibit 4(d)


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

                              ASSOCIATED BANC-CORP

                                       TO

                          THE BANK OF NEW YORK, Trustee





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





                                    INDENTURE



                        Dated as of _______________, 2001





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





                          SUBORDINATED DEBT SECURITIES


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



<PAGE>   2



   CERTAIN SECTIONS OF THIS INDENTURE RELATING TO SECTIONS 3.10 THROUGH 3.18,
                 INCLUSIVE, OF THE TRUST INDENTURE ACT OF 1939:

<TABLE>
<CAPTION>
        TRUST INDENTURE                                           INDENTURE
          ACT SECTION                                             SECTION
      -----------------                                           ---------
      <S>                                                        <C>
      ss. 3.10(a)(1)                                              6.09
               (a)(2)............................................ 6.09
               (a)(3)............................................ Not Applicable
               (a)(4)............................................ Not Applicable
               (b) .............................................. 6.08
                                                                  6.10
          ss. 3.11(a)............................................ 6.13
                  (b)............................................ 6.13
          ss. 3.12(a)............................................ 7.01
                                                                  7.02
                  (b)............................................ 7.02
                  (c)............................................ 7.02
          ss. 3.13(a)............................................ 7.03
                  (b)............................................ 7.03
                  (c)............................................ 7.03
                  (d)............................................ 7.04
          ss. 3.14(a)............................................ 1.01
                  (a)(4)......................................... 10.04
                  (b)............................................ Not Applicable
                  (c)(1)......................................... 102
                  (c)(2)......................................... 102
                  (c)(3)......................................... Not Applicable
                  (d)............................................ Not Applicable
                  (e)............................................ 1.02
          ss. 3.15(a)............................................ 6.01
                  (b)............................................ 6.02
                  (c)............................................ 6.01
                  (d)............................................ 6.01
                  (e)............................................ 5.14
          ss. 3.16(a)............................................ 1.01
               (a)(1)(A)......................................... 5.02
                                                                  5.12
               (a)(1)(B)......................................... 5.13
               (a)(2)............................................ Not Applicable
                  (b)                                             5.08
                  (c)............................................ 1.04
          ss. 3.17(a)(1)......................................... 5.03
                  (a)(2)......................................... 5.04
                  (b)............................................ 10.03
           ss.3.18(a)............................................ 1.07
</TABLE>

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

NOTE: This reconciliation and tie shall not, for any purpose, be deemed to be a
part of the Indenture.



<PAGE>   3



                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                  PAGE
                                                                                                  ----
<S>                                                                                                <C>
RECITALS OF THE COMPANY.............................................................................1

ARTICLE One Definitions and Other Provisions OF GENERAL APPLICATION.................................1

         SECTION 1.01.   Definitions................................................................1
         Act........................................................................................2
         Affiliate..................................................................................2
         Authenticating Agent.......................................................................2
         Bank.......................................................................................2
         Board of Directors.........................................................................2
         Board Resolution...........................................................................2
         Business Day...............................................................................2
         Commission.................................................................................2
         Common Stock...............................................................................2
         Company....................................................................................3
         Company Request............................................................................3
         Company Order..............................................................................3
         Corporate Trust Office.....................................................................3
         Corporation................................................................................3
         Covenant Defeasance........................................................................3
         Defaulted Interest.........................................................................3
         Defeasance.................................................................................3
         Depositary.................................................................................3
         Entitled Persons...........................................................................3
         Event of Default...........................................................................3
         Excess Proceeds............................................................................3
         Exchange Act...............................................................................3
         Existing Subordinated Indebtedness.........................................................3
         Expiration Date............................................................................3
         Final Conversion Date......................................................................3
         Foreign Government Obligations.............................................................4
         Global Security............................................................................4
         Holder.....................................................................................4
         Indenture..................................................................................4
         Initial Conversion Date....................................................................4
         Initial Conversion Price...................................................................4
         Interest...................................................................................4
         Interest Payment Date......................................................................4
         Investment Company Act.....................................................................4
         Junior Securities..........................................................................4
         Maturity...................................................................................4
         Notice of Default..........................................................................4
         Officers' Certificate......................................................................4
</TABLE>


                                       i

<PAGE>   4

<TABLE>

         <S>                                                                                       <C>
         Opinion of Counsel.........................................................................5
         Other Financial Obligations................................................................5
         Original Issue Discount Security...........................................................5
         Outstanding................................................................................5
         Paying Agent...............................................................................6
         Person.....................................................................................7
         Place of Payment...........................................................................7
         Predecessor Security.......................................................................7
         Redemption Date............................................................................7
         Redemption Price...........................................................................7
         Regular Record Date........................................................................7
         Responsible Officer........................................................................7
         Securities.................................................................................7
         Securities Act.............................................................................7
         Security Register..........................................................................7
         Security Registrar.........................................................................7
         Senior Indebtedness........................................................................7
         Special Record Date........................................................................8
         Stated Maturity............................................................................8
         Subsidiary.................................................................................8
         Trust Indenture Act........................................................................8
         Trustee....................................................................................8
         U.S. Government Obligation.................................................................8
         Vice President.............................................................................8
         SECTION 1.02.   Compliance Certificates and Opinions.......................................8
         SECTION 1.03.   Form of Documents Delivered to Trustee.....................................9
         SECTION 1.04.   Acts of Holders; Record Dates..............................................9
         SECTION 1.05.   Notices, Etc., to Trustee and Company.....................................12
         SECTION 1.06.   Notice to Holders; Waiver.................................................12
         SECTION 1.07.   Conflict with Trust Indenture Act.........................................12
         SECTION 1.08.   Effect of Headings and Table of Contents..................................12
         SECTION 1.09.   Successors and Assigns....................................................13
         SECTION 1.10.   Separability Clause.......................................................13
         SECTION 1.11.   Benefits of Indenture.....................................................13
         SECTION 1.12.   Governing Law.............................................................13
         SECTION 1.13.   Legal Holidays............................................................13

ARTICLE Two Security Forms.........................................................................13

         SECTION 2.01.   Forms Generally...........................................................13
         SECTION 2.02.   Form of Face of Security..................................................14
         SECTION 2.03.   Form of Reverse of Security...............................................16
         SECTION 2.04.   Form of Legend for Global Securities......................................20
         SECTION 2.05.   Form of Trustee's Certificate of Authentication...........................20

ARTICLE Three The Securities.......................................................................21

         SECTION 3.01.   Amount Unlimited; Issuable in Series......................................21
         SECTION 3.02.   Denominations.............................................................23
</TABLE>


                                       ii
<PAGE>   5

<TABLE>

         <S>                                                                                      <C>
         SECTION 3.03.   Execution, Authentication, Delivery and Dating............................23
         SECTION 3.04.   Temporary Securities......................................................25
         SECTION 3.05.   Registration; Registration of Transfer and Exchange.......................25
         SECTION 3.06.   Mutilated, Destroyed, Lost and Stolen Securities..........................27
         SECTION 3.07.   Payment of Interest; Interest Rights Preserved............................28
         SECTION 3.08.   Persons Deemed Owners.....................................................29
         SECTION 3.09.   Cancellation..............................................................29
         SECTION 3.10.   Computation of Interest...................................................30
         SECTION 3.11.   CUSIP Numbers.............................................................30

ARTICLE Four Satisfaction and Discharge............................................................30

         SECTION 4.01.   Satisfaction and Discharge of Indenture...................................30
         SECTION 4.02.   Application of Trust Money................................................31

ARTICLE Five Remedies..............................................................................31

         SECTION 5.01.   Events of Default.........................................................31
         SECTION 5.02.   Acceleration of Maturity; Rescission and Annulment........................33
         SECTION 5.03.   Collection of Indebtedness and Suits for Enforcement by Trustee...........33
         SECTION 5.04.   Trustee May File Proofs of Claim..........................................34
         SECTION 5.05.   Trustee May Enforce Claims Without Possession of Securities...............35
         SECTION 5.06.   Application of Money Collected............................................35
         SECTION 5.07.   Limitation on Suits.......................................................35
         SECTION 5.08.   Unconditional Right of Holders to Receive Principal,
                         Premium and Interest or to Convert........................................36
         SECTION 5.09.   Restoration of Rights and Remedies........................................36
         SECTION 5.10.   Rights and Remedies Cumulative............................................36
         SECTION 5.11.   Delay or Omission Not Waiver..............................................37
         SECTION 5.12.   Control by Holders........................................................37
         SECTION 5.13.   Waiver of Past Defaults...................................................37
         SECTION 5.14.   Undertaking for Costs.....................................................37
         SECTION 5.15.   Waiver of Usury, Stay or Extension Laws...................................38

ARTICLE Six The Trustee............................................................................38

         SECTION 6.01.   Certain Duties and Responsibilities.......................................38
         SECTION 6.02.   Notice of Defaults........................................................38
         SECTION 6.03.   Certain Rights of Trustee.................................................38
         SECTION 6.04.   Not Responsible for Recitals or Issuance of Securities....................40
         SECTION 6.05.   May Hold Securities.......................................................40
         SECTION 6.06.   Money Held in Trust.......................................................40
         SECTION 6.07.   Compensation and Reimbursement............................................40
         SECTION 6.08.   Conflicting Interests.....................................................41
         SECTION 6.09.   Corporate Trustee Required; Eligibility...................................41
         SECTION 6.10.   Resignation and Removal; Appointment of Successor.........................41
         SECTION 6.11.   Acceptance of Appointment by Successor....................................43
         SECTION 6.12.   Merger, Conversion, Consolidation or Succession to Business...............44
         SECTION 6.13.   Preferential Collection of Claims Against Company.........................44
</TABLE>


                                      iii

<PAGE>   6

<TABLE>
         <S>                                                                                      <C>
         SECTION 6.14.   Appointment of Authenticating Agent.......................................44

ARTICLE Seven Holders' Lists and Reports by Trustee and Company....................................46

         SECTION 7.01.   Company to Furnish Trustee Names and Addresses of Holders.................46
         SECTION 7.02.   Preservation of Information; Communications to Holders....................46
         SECTION 7.03.   Reports by Trustee........................................................46
         SECTION 7.04.   Reports by Company........................................................47

ARTICLE Eight Consolidation, Merger, Conveyance, Transfer or Lease.................................47

         SECTION 8.01.   Company May Consolidate, Etc., Only on Certain Terms......................47
         SECTION 8.02.   Successor Substituted.....................................................48

ARTICLE Nine Supplemental Indentures...............................................................48

         SECTION 9.01.   Supplemental Indentures Without Consent of Holders........................48
         SECTION 9.02.   Supplemental Indentures with Consent of Holders...........................49
         SECTION 9.03.   Execution of Supplemental Indentures......................................50
         SECTION 9.04.   Effect of Supplemental Indentures.........................................50
         SECTION 9.05.   Conformity with Trust Indenture Act.......................................50
         SECTION 9.06.   Reference in Securities to Supplemental Indentures........................51
         SECTION 9.07.   Subordination Unimpaired..................................................51

ARTICLE Ten Covenants..............................................................................51

         SECTION 10.01.   Payment of Principal, Premium and Interest...............................51
         SECTION 10.02.   Maintenance of Office or Agency..........................................51
         SECTION 10.03.   Money for Securities Payments to Be Held in Trust........................52
         SECTION 10.04.   Statement by Officers as to Default......................................53
         SECTION 10.05.   Existence................................................................53
         SECTION 10.06.   Maintenance of Properties................................................53
         SECTION 10.07.   Payment of Taxes and Other Claims........................................53
         SECTION 10.08.   Waiver of Certain Covenants..............................................54
         SECTION 10.09.   Calculation of Original Issue Discount...................................54

ARTICLE Eleven Redemption of Securities............................................................54

         SECTION 11.01.   Applicability of Article.................................................54
         SECTION 11.02.   Election to Redeem; Notice to Trustee....................................54
         SECTION 11.03.   Selection by Trustee of Securities to Be Redeemed........................55
         SECTION 11.04.   Notice of Redemption.....................................................55
         SECTION 11.05.   Deposit of Redemption Price..............................................56
         SECTION 11.06.   Securities Payable on Redemption Date....................................56
         SECTION 11.07.   Securities Redeemed in Part..............................................57

ARTICLE Twelve Sinking Funds.......................................................................57

         SECTION 12.01.   Applicability of Article.................................................57
         SECTION 12.02.   Satisfaction of Sinking Fund Payments with Securities....................57
</TABLE>


                                       iv

<PAGE>   7

<TABLE>

         <S>                                                                                      <C>
         SECTION 12.03.   Redemption of Securities for Sinking Fund................................58

ARTICLE Thirteen Defeasance and Covenant Defeasance................................................58

         SECTION 13.01.   Company's Option to Effect Defeasance or Covenant Defeasance.............58
         SECTION 13.02.   Defeasance and Discharge.................................................58
         SECTION 13.03.   Covenant Defeasance......................................................59
         SECTION 13.04.   Conditions to Defeasance or Covenant Defeasance..........................59
         SECTION 13.05.   Deposited Money and U.S. Government Obligations to Be
                          Held in Trust; Miscellaneous Provisions..................................61
         SECTION 13.06.   Reinstatement............................................................62

ARTICLE Fourteen Subordination of Securities.......................................................62

         SECTION 14.01.   Securities Subordinate to Senior Indebtedness............................62
         SECTION 14.02.   Payment Over of Proceeds Upon Dissolution, Etc...........................62
         SECTION 14.03.   Prior Payment to Senior Indebtedness Upon Acceleration of Securities.....63
         SECTION 14.04.   No Payment When Senior Indebtedness in Default...........................64
         SECTION 14.05.   Payment Permitted in Certain Situations..................................64
         SECTION 14.06.   Subrogation to Rights of Holders of Senior Indebtedness..................65
         SECTION 14.07.   Provisions Solely to Define Relative Rights..............................65
         SECTION 14.08.   Trustee to Effectuate Subordination......................................65
         SECTION 14.09.   No Waiver of Subordination Provisions....................................65
         SECTION 14.10.   Notice to Trustee........................................................66
         SECTION 14.11.   Reliance on Judicial Order or Certificate of Liquidating Agent...........67
         SECTION 14.12.   Trustee Not Fiduciary for Holders of Senior Indebtedness
                          or Entitled Persons......................................................67
         SECTION 14.13.   Rights of Trustee as Holder of Senior Indebtedness or
                          Entitled Person; Preservation of Trustee's Rights........................67
         SECTION 14.14.   Article Applicable to Paying Agents......................................67
         SECTION 14.15.   Securities to Rank Pari Passu with Existing Subordinated
                          Indebtedness; Payment of Proceeds in Certain Cases.......................68
         SECTION 14.16.   Certain Conversions Deemed Payment.......................................69

ARTICLE Fifteen Conversion of Securities...........................................................70

         SECTION 15.01.   Applicability of Article.................................................70
         SECTION 15.02.   Conversion Privilege and Conversion Price................................70
         SECTION 15.03.   Exercise of Conversion Privilege.........................................70
         SECTION 15.04.   Fractions of Shares......................................................71
         SECTION 15.05.   Adjustment of Conversion Price...........................................71
         SECTION 15.06.   Notice of Adjustments of Conversion Price................................73
         SECTION 15.07.   Notice of Certain Corporate Action.......................................74
         SECTION 15.08.   Company to Reserve Common Stock..........................................74
         SECTION 15.09.   Taxes on Conversions.....................................................75
         SECTION 15.10.   Covenant as to Common Stock..............................................75
         SECTION 15.11.   Cancellation of Converted Securities.....................................75
         SECTION 15.12.   Provisions in Case of Consolidation, Merger or Sale of Assets............75
</TABLE>


                                       v
<PAGE>   8

<TABLE>
         <S>                                                                                      <C>
         SECTION 15.13.   Responsibility of Trustee................................................76
</TABLE>








                                       vi

<PAGE>   9

         INDENTURE, dated as of ___________, 2001 between Associated Banc-Corp,
a corporation duly organized and existing under the laws of the State of
Wisconsin (herein called the "Company"), having its principal office at 1200
Hansen Road, Green Bay, Wisconsin 54304, and The Bank of New York, a New York
banking corporation, as Trustee (herein called the "Trustee").

                             RECITALS OF THE COMPANY

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

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

         NOW, THEREFORE, THIS INDENTURE WITNESSETH:

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


                                  ARTICLE ONE

             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

SECTION 1.01. Definitions.

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

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

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

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

              (4) unless the context otherwise requires, any reference to an
         "Article" or a "Section" refers to an Article or a Section, as the case
         may be, of this Indenture; and

              (5) the words "herein", "hereof" and "hereunder" and other words
         of similar import refer to this Indenture as a whole and not to any
         particular Article, Section or other subdivision.
<PAGE>   10

                                                                              2

              "Act", when used with respect to any Holder, has the meaning
         specified in Section 1.04.

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

              "Authenticating Agent" means any Person authorized by the Trustee
         pursuant to Section 6.14 to act on behalf of the Trustee to
         authenticate Securities of one or more series.

              "Bank" means (i) any institution which accepts deposits that the
         depositor has a legal right to withdraw on demand and engages in the
         business of making commercial loans, and (ii) any trust company.

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

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

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

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

              "Common Stock" includes any stock of any class of the Company that
         has no preference in respect of dividends or of amounts payable in the
         event of any voluntary or involuntary liquidation, dissolution or
         winding-up of the Company and that is not subject to redemption by the
         Company. However, subject to the provisions of Section 15.12, shares
         issuable on conversion of Securities shall include only shares of the
         class designated as Common Stock of the Company at the date of this
         instrument or shares of any class or classes resulting from any
         reclassification or reclassifications thereof and that have no
         preference in respect of dividends or of amounts payable in the event
         of any voluntary or involuntary liquidation, dissolution or winding-up
         of the Company and that are no subject to redemption by the Company;
         provided that if at any time there shall be more than one such
         resulting class, the shares of each such class then so issuable shall
         be substantially in the proportion that the total number of shares of
         such class resulting from



<PAGE>   11
                                                                              3
         all such reclassifications bears to the total number of shares of all
         such classes resulting from all such reclassifications.

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

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

              "Corporate Trust Office" means the principal office of the Trustee
         in New York, New York at which at any particular time its corporate
         trust business shall be administered, which, at the date hereof, is
         located at 101 Barclay Street, Floor 21 West, New York, New York,
         10286.

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

              "Covenant Defeasance" has the meaning specified in Section 13.03.

              "Defaulted Interest" has the meaning specified in Section 3.07.

              "Defeasance" has the meaning specified in Section 13.02.

              "Depositary" means, with respect to Securities of any series
         issuable in whole or in part in the form of one or more Global
         Securities, a clearing agency registered under the Exchange Act that is
         designated to act as Depositary for such Securities as contemplated by
         Section 3.01.

              "Entitled Persons" means any Person entitled to payment pursuant
         to the terms of "Other Financial Obligations."

              "Event of Default" has the meaning specified in Section 5.01.

              "Excess Proceeds" has the meaning specified in Section 14.15(c).

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

              ["Existing Subordinated Indebtedness" means the Company's ____
         Notes due _________.]

              "Expiration Date" has the meaning specified in Section 1.04.

              "Final Conversion Date", when used with respect to any Security,
         means the last day on which such Security shall be convertible into
         Common Stock.
<PAGE>   12
                                                                              4
              "Foreign Government Obligations" has the meaning specified in
         Section 13.04.

              "Global Security" means a Security that evidences all or part of
         the Securities of any series and bears the legend set forth in Section
         2.04 (or such legend as may be specified as contemplated by Section
         3.01 for such Securities).

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

              "Indenture" means this instrument as originally executed and as it
         may from time to time be supplemented or amended by one or more
         indentures supplemental hereto entered into pursuant to the applicable
         provisions hereof, including, for all purposes of this instrument and
         any such supplemental indenture, the provisions of the Trust Indenture
         Act that are deemed to be a part of and govern this instrument and any
         such supplemental indenture, respectively. The term "Indenture" shall
         also include the terms of particular series of Securities established
         as contemplated by Section 3.01.

              "Initial Conversion Date", when used with respect to any Security,
         means the first day on which such Security shall be convertible into
         Common Stock.

              "Initial Conversion Price", when used with respect to any
         Security, means the price at which the Common Stock shall be delivered
         upon conversion of such Security, prior to any adjustment of such price
         as provided herein.

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

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

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

              "Junior Securities" has the meaning specified in Section 14.16.

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

              "Notice of Default" means a written notice of the kind specified
         in Section 5.01(4).

              "Officers' Certificate" means a certificate signed by the Chairman
         of the Board, a Vice Chairman of the Board, the President or a Vice
         President, and by the Treasurer, an Assistant Treasurer, the Secretary
         or an Assistant Secretary, of the Company, and delivered to the
         Trustee. One of the officers signing an Officers' Certificate given
         pursuant to Section 10.04 shall be the principal executive, financial
         or accounting officer of the Company.
<PAGE>   13
                                                                              5
              "Opinion of Counsel" means a written opinion of counsel, who may
         be counsel for the Company, and who shall be acceptable to the Trustee.

              "Other Financial Obligations" means, unless otherwise determined
         with respect to any series of Securities pursuant to Section 3.01,
         whether outstanding on the date of the indenture or thereafter created,
         incurred or assumed, all obligations of the Company to make payment
         pursuant to the terms of financial instruments such as (i) securities
         contracts and foreign currency exchange contracts, (ii) derivative
         instruments, such as swap agreements (including interest rate and
         foreign exchange rate swap agreements), cap agreements, floor
         agreements, collar agreements, interest rate agreements, foreign
         exchange rate agreements, options, commodity futures contracts and
         commodity options contracts and (iii) financial instruments similar to
         those set forth in (i) or (ii) above; provided, however, that Other
         Financial Obligations shall not include (A) obligations on account of
         Senior Indebtedness and (B) obligations on account of indebtedness for
         money borrowed ranking pari passu with or subordinate to the
         Securities, including, without limitation, Existing Subordinated
         Indebtedness.

              "Original Issue Discount Security" means any Security which
         provides for an amount less than the principal amount thereof to be due
         and payable upon a declaration of acceleration of the Maturity thereof
         pursuant to Section 5.02.

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

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

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

              (3) Securities as to which Defeasance has been effected pursuant
         to Section 13.02; and

              (4) Securities which have been paid pursuant to Section 3.06 or in
         exchange for or in lieu of which other Securities have been
         authenticated and delivered pursuant to this Indenture, other than any
         such Securities in respect of which there shall have been presented to
         the Trustee proof satisfactory to it that such Securities are held by a
         bona fide purchaser in whose hands such Securities are valid
         obligations of the Company;

         provided, however, that in determining whether the Holders of the
         requisite principal amount of the Outstanding Securities have given,
         made or taken any request, demand, authorization, direction, notice,
         consent, waiver or other action hereunder as of any date, (A) the
         principal amount of an Original Issue Discount Security which shall be
         deemed to be Outstanding shall be the amount of the


<PAGE>   14
                                                                              6
         principal thereof which would be due and payable as of such date upon
         acceleration of the Maturity thereof to such date pursuant to Section
         5.02, (B) if, as of such date, the principal amount payable at the
         Stated Maturity of a Security is not determinable, the principal amount
         of such Security which shall be deemed to be Outstanding shall be the
         amount as specified or determined as contemplated by Section 3.01, (C)
         the principal amount of a Security denominated in one or more foreign
         currencies or currency units which shall be deemed to be Outstanding
         shall be the U.S. dollar equivalent, determined as of such date in the
         manner provided as contemplated by Section 3.01, of the principal
         amount of such Security (or, in the case of a Security described in
         Clause (A) or (B) above, of the amount determined as provided in such
         Clause), and (D) Securities owned by the Company or any other obligor
         upon the Securities or any Affiliate of the Company or of such other
         obligor shall be disregarded and deemed not to be Outstanding, except
         that, in determining whether the Trustee shall be protected in relying
         upon any such request, demand, authorization, direction, notice,
         consent, waiver or other action, only Securities which a Responsible
         Officer of the Trustee actually knows to be so owned shall be so
         disregarded. Securities so owned which have been pledged in good faith
         may be regarded as Outstanding if the pledgee establishes to the
         satisfaction of the Trustee the pledgee's right so to act with respect
         to such Securities and that the pledgee is not the Company or any other
         obligor upon the Securities or any Affiliate of the Company or of such
         other obligor.

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

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

              "Place of Payment", when used with respect to the Securities of
         any series, means the place or places where the principal of and any
         premium and interest on the Securities of that series are payable as
         specified as contemplated by Section 3.01.

              "Predecessor Security" of any particular Security means every
         previous Security evidencing all or a portion of the same debt as that
         evidenced by such particular Security; and, for the purposes of this
         definition, any Security authenticated and delivered under Section 3.06
         in exchange for or in lieu of a mutilated, destroyed, lost or stolen
         Security shall be deemed to evidence the same debt as the mutilated,
         destroyed, lost or stolen Security.

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

              "Redemption Price", when used with respect to any Security to be
         redeemed, means the price at which it is to be redeemed pursuant to
         this Indenture.
<PAGE>   15
                                                                              7
              "Regular Record Date" for the interest payable on any Interest
         Payment Date on the Securities of any series means the date specified
         for that purpose as contemplated by Section 3.01.

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

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

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

              "Security Register" and "Security Registrar" have the respective
         meanings specified in Section 3.05.

              "Senior Indebtedness" means the principal of (and premium, if any)
         and interest on (a) all indebtedness of the Company (including
         indebtedness of others guaranteed by the Company), other than the
         Securities and obligations on account of Existing Subordinated
         Indebtedness whether outstanding on the date of this Indenture or
         thereafter created, incurred or assumed, which is (i) for money
         borrowed or (ii) evidenced by a note or similar instrument given in
         connection with the acquisition of any businesses, properties or assets
         of any kind, and (b) amendments, renewals, extensions, modifications or
         refundings of any such indebtedness, unless in any case in the
         instrument creating or evidencing any such indebtedness or pursuant to
         which the same is outstanding it is provided that such indebtedness is
         not superior in right of payment to the Securities or is to rank pari
         passu with or subordinate to the Securities.

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

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

              "Subsidiary" means a corporation more than 50% of the outstanding
         voting stock of which is owned, directly or indirectly, by the Company
         or by one or more other Subsidiaries, or by the Company and one or more
         other Subsidiaries. For the purposes of this definition, "voting stock"
         means stock which ordinarily has voting power for the election of
         directors, whether at all times or only so long as no senior class of
         stock has such voting power by reason of any contingency.
<PAGE>   16
                                                                              8
              "Trust Indenture Act" means the Trust Indenture Act of 1939 as in
         force at the date as of which this instrument was executed; provided,
         however, that in the event the Trust Indenture Act of 1939 is amended
         after such date, "Trust Indenture Act" means, to the extent required by
         any such amendment, the Trust Indenture Act of 1939 as so amended.

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

              "U.S. Government Obligation" has the meaning specified in Section
         13.04.

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

SECTION 1.02. Compliance Certificates and Opinions.

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

         Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture (except for certificates
provided for in Section 10.04) shall include,

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

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

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

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

SECTION 1.03. Form of Documents Delivered to Trustee.

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


<PAGE>   17
                                                                              9
one document, but one such Person may certify or give an opinion with respect to
some matters and one or more other such Persons as to other matters, and any
such Person may certify or give an opinion as to such matters in one or several
documents.

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

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

SECTION 1.04. Acts of Holders; Record Dates.

              (a) Any request, demand, authorization, direction, notice,
         consent, waiver or other action provided or permitted by this Indenture
         to be given, made or taken by Holders may be embodied in and evidenced
         by one or more instruments of substantially similar tenor signed by
         such Holders in person or by agent duly appointed in writing; and,
         except as herein otherwise expressly provided, such action shall become
         effective when such instrument or instruments are delivered to the
         Trustee and, where it is hereby expressly 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
         6.01) conclusive in favor of the Trustee and 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 a certificate of a notary public or other officer
         authorized by law to take acknowledgments of deeds, certifying that the
         individual signing such instrument or writing acknowledged to him the
         execution thereof. Where such execution is by a signer acting in a
         capacity other than his individual capacity, such certificate or
         affidavit shall also constitute sufficient proof of his authority. The
         fact and date of the execution of any such instrument or writing, or
         the authority of the Person executing the same, may also be proved in
         any other manner which the Trustee deems sufficient.

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

              (d) Any request, demand, authorization, direction, notice,
         consent, waiver or other Act of the Holder of any Security shall bind
         every future Holder of the same Security and the Holder of every
         Security issued upon the registration of transfer thereof or in
         exchange therefor or in lieu thereof in respect of anything done,
         omitted or suffered



<PAGE>   18
                                                                             10
         to be done by the Trustee or the Company in reliance thereon, whether
         or not notation of such action is made upon such Security.

              (e) The Company may set any day as a record date for the purpose
         of determining the Holders of Outstanding Securities of any series
         entitled to give, make or take any request, demand, authorization,
         direction, notice, consent, waiver or other action provided or
         permitted by this Indenture to be given, made or taken by Holders of
         Securities of such series, provided that the Company may not set a
         record date for, and the provisions of this paragraph shall not apply
         with respect to, the giving or making of any notice, declaration,
         request or direction referred to in the next paragraph. If any record
         date is set pursuant to this paragraph, the Holders of Outstanding
         Securities of the relevant series on such record date, and no other
         Holders, shall be entitled to take the relevant action, whether or not
         such Holders remain Holders after such record date; provided that no
         such action shall be effective hereunder unless taken on or prior to
         the applicable Expiration Date by Holders of the requisite principal
         amount of Outstanding Securities of such series on such record date.
         Nothing in this paragraph shall be construed to prevent the Company
         from setting a new record date for any action for which a record date
         has previously been set pursuant to this paragraph (whereupon the
         record date previously set shall automatically and with no action by
         any Person be cancelled and of no effect), and nothing in this
         paragraph shall be construed to render ineffective any action taken by
         Holders of the requisite principal amount of Outstanding Securities of
         the relevant series on the date such action is taken. Promptly after
         any record date is set pursuant to this paragraph, the Company, at its
         own expense, shall cause notice of such record date, the proposed
         action by Holders and the applicable Expiration Date to be given to the
         Trustee in writing and to each Holder of Securities of the relevant
         series in the manner set forth in Section 1.06.

              (f) The Trustee may set any day as a record date for the purpose
         of determining the Holders of Outstanding Securities of any series
         entitled to join in the giving or making of (i) any Notice of Default,
         (ii) any declaration of acceleration referred to in Section 5.02, (iii)
         any request to institute proceedings referred to in Section 5.07(2) or
         (iv) any direction referred to in Section 3.05(2) or Section 5.12, in
         each case with respect to Securities of such series. If any record date
         is set pursuant to this paragraph, the Holders of Outstanding
         Securities of such series on such record date, and no other Holders,
         shall be entitled to join in such notice, declaration, request or
         direction, whether or not such Holders remain Holders after such record
         date; provided that no such action shall be effective hereunder unless
         taken on or prior to the applicable Expiration Date by Holders of the
         requisite principal amount of Outstanding Securities of such series on
         such record date. Nothing in this paragraph shall be construed to
         prevent the Trustee from setting a new record date for any action for
         which a record date has previously been set pursuant to this paragraph
         (whereupon the record date previously set shall automatically and with
         no action by any Person be cancelled and of no effect), and nothing in
         this paragraph shall be construed to render ineffective any action
         taken by Holders of the requisite principal amount of Outstanding
         Securities of the relevant series on the date such action is taken.
         Promptly after any record date is set pursuant to this paragraph, the
         Trustee, at the Company's expense, shall cause notice of such record
         date, the proposed action by Holders and the applicable Expiration Date
         to be given to the Company in



<PAGE>   19
                                                                             11
         writing and to each Holder of Securities of the relevant series in the
         manner set forth in Section 1.06.

              (g) With respect to any record date set pursuant to this Section,
         the party hereto which sets such record dates may designate any day as
         the "Expiration Date" and from time to time may change the Expiration
         Date to any earlier or later day; provided that no such change shall be
         effective unless notice of the proposed new Expiration Date is given to
         the other party hereto in writing, and to each Holder of Securities of
         the relevant series in the manner set forth in Section 1.06, on or
         prior to the existing Expiration Date. If an Expiration Date is not
         designated with respect to any record date set pursuant to this
         Section, the party hereto which set such record date shall be deemed to
         have initially designated the 90th day after such record date as the
         Expiration Date with respect thereto, subject to its right to change
         the Expiration Date as provided in this paragraph. Notwithstanding the
         foregoing, no Expiration Date shall be later than the 90th day after
         the applicable record date.

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

SECTION 1.05. Notices, Etc., to Trustee and Company.

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

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

              (2) the Company by the Trustee or by any Holder shall be
         sufficient for every purpose hereunder (unless otherwise herein
         expressly provided) if in writing 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 1.06. Notice to Holders; Waiver.

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



<PAGE>   20
                                                                             12
the equivalent of such notice. Waivers of notice by Holders shall be filed with
the Trustee, but such filing shall not be a condition precedent to the validity
of any action taken in reliance upon such waiver.

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

SECTION 1.07. Conflict with Trust Indenture Act.

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

SECTION 1.08. 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 1.09. 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 Securities shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions shall not in any way be affected or impaired thereby.

SECTION 1.11. Benefits of Indenture.

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

SECTION 1.12. Governing Law.

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

SECTION 1.13. Legal Holidays.

         In any case where any Interest Payment Date, Redemption Date or Stated
Maturity of any Security or the last date on which a Holder has the right to
convert his Securities shall not be a Business Day at any Place of Payment, then
(notwithstanding any other provision of this



<PAGE>   21
                                                                             13

Indenture or of the Securities (other than a provision of any Security which
specifically states that such provision shall apply in lieu of this Section))
payment of interest or principal (and premium, if any) or conversion of the
Securities need not be made at such Place of Payment on such date, but may be
made on the next succeeding Business Day at such Place of Payment with the same
force and effect as if made on the Interest Payment Date or Redemption Date, or
at the Stated Maturity, or on such last day for conversion, provided that no
interest shall accrue with respect to such payment for the period from and after
such Interest Payment Date, Redemption Date or Stated Maturity, as the case may
be.

                                  ARTICLE TWO

                                 SECURITY FORMS

SECTION 2.01. Forms Generally.

         The Securities of each series shall be in substantially the form set
forth in this Article, or in such other form as shall be established by or
pursuant to a Board Resolution or in one or more indentures supplemental hereto,
in each case with such appropriate insertions, omissions, substitutions and
other variations as are required or permitted by this Indenture, and may have
such letters, numbers or other marks of identification and such legends or
endorsements placed thereon as may be required to comply with the rules of any
securities exchange or Depositary therefor or as may, consistently herewith, be
determined by the officers executing such Securities, as evidenced by their
execution thereof. If the form of Securities of any series is established by
action taken pursuant to a Board Resolution, a copy of an appropriate record of
such action shall be certified by the Secretary or an Assistant Secretary of the
Company and delivered to the Trustee at or prior to the delivery of the Company
Order contemplated by Section 3.03 for the authentication and delivery of such
Securities.

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

SECTION 2.02. Form of Face of Security.

         [Insert any legend required by the Internal Revenue Code and the
regulations thereunder.] THIS NOTE IS NOT A DEPOSIT AND IS NOT INSURED BY THE
FEDERAL DEPOSIT INSURANCE CORPORATION, THE BANK INSURANCE FUND, THE SAVINGS
ASSOCIATION INSURANCE FUND OR ANY OTHER GOVERNMENTAL AGENCY.

                              ASSOCIATED BANC-CORP

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

                                                             CUSIP No. ________

No.  _______                                                         $ ________


         Associated Banc-Corp, a corporation duly organized and existing under
the laws of Wisconsin (herein called the "Company", which term includes any
successor Person under the


<PAGE>   22
                                                                             14

Indenture hereinafter referred to), for value received, hereby promises to pay
to _____________, or registered assigns, the principal sum of ___________
Dollars on ________________ [if the Security is to bear interest prior to
Maturity, insert -- , and to pay interest thereon from ___________ or from the
most recent Interest Payment Date to which interest has been paid or duly
provided for, semi-annually on ___________ and ___________ in each year,
commencing ___________ at the rate of ___% per annum, until the principal hereof
is paid or made available for payment [if applicable, insert -- , provided that
any principal and premium, and any such installment of interest, which is
overdue shall bear interest at the rate of ___% per annum (to the extent that
the payment of such interest shall be legally enforceable), from the dates such
amounts are due until they are paid or made available for payment, and such
interest shall be payable on demand]. The interest so payable, and punctually
paid or duly provided for, on any Interest Payment Date will, as provided in
such Indenture, be paid to the Person in whose name this Security (or one or
more Predecessor Securities) is registered at the close of business on the
Regular Record Date for such interest, which shall be the _______ or _______
(whether or not a Business Day), as the case may be, next preceding such
Interest Payment Date. Any such interest not so punctually paid or duly provided
for will 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 Security (or one or more
Predecessor Securities) 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 Securities of this series
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 Securities of this series may be listed, and
upon such notice as may be required by such exchange, all as more fully provided
in said Indenture].

[If the Security is not to bear interest prior to Maturity, insert -- The
principal of this Security shall not bear interest except in the case of a
default in payment of principal upon acceleration, upon redemption or at Stated
Maturity and in such case the overdue principal and any overdue premium shall
bear interest at the rate of ___% per annum (to the extent that the payment of
such interest shall be legally enforceable), from the dates such amounts are due
until they are paid or made available for payment. Interest on any overdue
principal or premium shall be payable on demand. [Any such interest on overdue
principal or premium which is not paid on demand shall bear interest at the rate
of ___% per annum (to the extent that the payment of such interest on interest
shall be legally enforceable), from the date of such demand until the amount so
demanded is paid or made available for payment. Interest on any overdue interest
shall be payable on demand.]]

         Payment of the principal of (and premium, if any) and [if applicable,
insert -- any such] interest on this Security will be made at the office or
agency of the Company maintained for that purpose in ___________ 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 [if applicable, insert -- ;
provided, however, that at the option of the Company payment of interest may be
made by check mailed to the address of the Person entitled thereto as such
address shall appear in the Security Register].

         [Interest on this Security shall be computed on the basis of a 360-day
year of twelve 30-day months.]
<PAGE>   23
                                                                             15

         Reference is hereby made to the further provisions of this Security 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 Security
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:
                                      ASSOCIATED BANC-CORP

                                            By_____________________
Attest:


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

SECTION 2.03. Form of Reverse of Security.

         This Security is one of a duly authorized issue of securities of the
Company (herein called the "Securities"), issued and to be issued in one or more
series under an Indenture, dated as of ___________ (herein called the
"Indenture", which term shall have the meaning assigned to it in such
instrument), between the Company and The Bank of New York, as Trustee (herein
called the "Trustee", which term includes any successor trustee under the
Indenture), and reference is hereby made to the Indenture for a statement of the
respective rights, limitations of rights, duties and immunities thereunder of
the Company, the Trustee and the Holders of the Securities and of the terms upon
which the Securities are, and are to be, authenticated and delivered. This
Security is one of the series designated on the face hereof [, limited in
aggregate principal amount to [$] ___________].

         [If applicable, insert -- The Securities of this series are subject to
redemption upon not less than 30 days' notice by mail, [if applicable, insert --
(1) on ___________ in any year commencing with the year ____ and ending with the
year ____ through operation of the sinking fund for this series at a Redemption
Price equal to 100% of the principal amount, and (2)] at any time [if
applicable, insert -- on or after _______, ____], as a whole or in part, at the
election of the Company, at the following Redemption Prices (expressed as
percentages of the principal amount): If redeemed [if applicable, insert -- on
or before ___________, ____%, and if redeemed] during the 12-month period
beginning ___________ of the years indicated,

<TABLE>
<CAPTION>

                                      Redemption                                           Redemption
            Year                        Price                        Year                    Price
            ----                      ----------                     ----                  ----------
<S>                                    <C>                           <C>                    <C>


</TABLE>

<PAGE>   24

                                                                             16

and thereafter at a Redemption Price equal to___% of the principal amount,
together in the case of any such redemption [if applicable, insert -- (whether
through operation of the sinking fund or otherwise)] with accrued interest to
the Redemption Date, but interest installments whose Stated Maturity is on or
prior to such Redemption Date will be payable to the Holders of such Securities,
or one or more Predecessor Securities, of record at the close of business on the
relevant Record Dates referred to on the face hereof, all as provided in the
Indenture.]

         [If applicable, insert -- Subject to and in compliance with the
provisions of the Indenture, the Holder of this Security is entitled, at his
option, at any time on or after the opening of business on the Initial
Conversion Date and on or before the close of business on the Final Conversion
Date, or in case this Security or a portion hereof is called for redemption,
then in respect of this Security or such portion hereof until and including, but
(unless the Company defaults in making the payment due upon redemption) not
after, the close of business on the Redemption Date, to convert this Security
(or any portion of the principal amount hereof which is $1,000 or an integral
multiple thereof), at the principal amount hereof, or of such portion, into
fully paid and non-assessable shares (calculated as to each conversion to the
nearest 1/100 of a share) of Common Stock of the Company at the Initial
Conversion Price (or at the current adjusted conversion price if an adjustment
has been made as provided in the Indenture) by surrender of this Security, duly
endorsed or assigned to the Company or in blank, to the Company at its office or
agency in the Borough of Manhattan, The City of New York, accompanied by written
notice to the Company that the Holder hereof elects to convert this Security, or
if less than the entire principal amount hereof is to be converted, the portion
hereof to be converted, and, in case such surrender shall be made during the
period from the close of business on any Regular Record Date next preceding any
Interest Payment Date (unless this Security or the portion thereof being
converted has been called for redemption on a Redemption Date within such
period), also accompanied by payment in New York Clearing House or other funds
acceptable to the Company of an amount equal to the interest payable on such
Interest Payment Date on the principal amount of this Security then being
converted. Subject to the aforesaid requirement for payment in the case of a
conversion after the Regular Record Date next preceding any Interest Payment
Date and on or before such Interest Payment Date, to the right of the Holder of
this Security (or any Predecessor Security) of record at such Regular Record
Date to receive an installment of interest (with certain exceptions provided in
the Indenture), no payment or adjustment is to be made on conversion for
interest accrued hereon or for dividends on the Common Stock issued on
conversion. No fractions of shares or scrip representing fractions of shares
will be issued on conversion, but instead of any fractional interest the Company
shall pay a cash adjustment as provided in the Indenture. The conversion price
is subject to adjustment as provided in the Indenture. In addition, the
Indenture provides that in case of certain consolidations or mergers to which
the Company is a party or the transfer of substantially all of the assets of the
Company, the Indenture shall be amended, without the consent of any Holders of
Securities, so that this Security, if then outstanding, will be convertible
thereafter, during the period this Security shall be convertible as specified
above, only into the kind and amount of securities, cash and other property
receivable upon the consolidation, merger or transfer by a holder of the number
of shares of Common Stock into which this Security might have been converted
immediately prior to such consolidation, merger or transfer (assuming such
holder of Common Stock failed to exercise any rights of election and received
per share the kind and amount received per share by a plurality of non-electing
shares), assuming, if such consolidation, merger or transfer is prior to the
Initial Conversion Date, that is Security were convertible at the time of such
consolidation, merger or transfer at the Initial Conversion Price


<PAGE>   25
                                                                             17

specified above as adjusted from the date of establishment of the Initial
Conversion Price to such time pursuant to the Indenture.]

         [If applicable, insert -- The Securities of this series are subject to
redemption upon not less than 30 days' notice by mail, (1) on _______ in any
year commencing with the year .... and ending with the year ____ through
operation of the sinking fund for this series at the Redemption Prices for
redemption through operation of the sinking fund (expressed as percentages of
the principal amount) set forth in the table below, and (2) at any time [if
applicable, insert -- on or after _______.], as a whole or in part, at the
election of the Company, at the Redemption Prices for redemption otherwise than
through operation of the sinking fund (expressed as percentages of the principal
amount) set forth in the table below: If redeemed during the 12-month period
beginning _______ of the years indicated,

<TABLE>
<CAPTION>
                                         Redemption Price                    Redemption Price For
                                          For Redemption                     Redemption Otherwise
                                        Through Operation                   Than Through Operation
  Year                                 of the Sinking Fund                    of the Sinking Fund
  ----                                 -------------------                  ----------------------
<S>                                    <C>                                   <C>


</TABLE>


and thereafter at a Redemption Price equal to ___% of the principal amount,
together in the case of any such redemption (whether through operation of the
sinking fund or otherwise) with accrued interest to the Redemption Date, but
interest installments whose Stated Maturity is on or prior to such Redemption
Date will be payable to the Holders of such Securities, or one or more
Predecessor Securities, of record at the close of business on the relevant
Record Dates referred to on the face hereof, all as provided in the Indenture.]

         [If applicable, insert -- Notwithstanding the foregoing, the Company
may not, prior to _______, redeem any Securities of this series as contemplated
by [if applicable, insert -- Clause (2) of] the preceding paragraph as a part
of, or in anticipation of, any refunding operation by the application, directly
or indirectly, of moneys borrowed having an interest cost to the Company
(calculated in accordance with generally accepted financial practice) of less
than ___% per annum.]

         [If applicable, insert -- The sinking fund for this series provides for
the redemption on _______ in each year beginning with the year ____ and ending
with the year ____ of [if applicable, insert -- not less than $_______
("mandatory sinking fund") and not more than] $_______ aggregate principal
amount of Securities of this series. Securities of this series acquired or
redeemed by the Company otherwise than through [if applicable, insert --
mandatory] sinking fund payments may be credited against subsequent [if
applicable, insert -- mandatory] sinking fund payments otherwise required to be
made [if applicable, insert -- , in the inverse order in which they become
due].]
<PAGE>   26

                                                                             18

         [If the Security is subject to redemption of any kind, insert -- In the
event of redemption of this Security in part only, a new Security or Securities
of this series and of like tenor for the unredeemed portion hereof will be
issued in the name of the Holder hereof upon the cancellation hereof.]

         The Company covenants and agrees, and each Holder of a Security, by his
acceptance thereof, likewise covenants and agrees, that, to the extent and in
the manner set forth in Article Fourteen of the Indenture, the indebtedness
represented by the Securities and the payment of principal of (and premium, if
any) and interest on each and all of the Securities are hereby expressly made
subordinate and subject in right of payment to the prior payment in full of all
Senior Indebtedness and Other Financial Obligations.

         [If applicable, insert -- The Indenture contains provisions for
defeasance at any time of [the entire indebtedness of this Security] [or]
[certain restrictive covenants and Events of Default with respect to this
Security] [, in each case] upon compliance with certain conditions set forth in
the Indenture.]

         [If the Security is not an Original Issue Discount Security, insert --
If an Event of Default with respect to Securities of this series shall occur and
be continuing, the principal of the Securities of this series may be declared
due and payable in the manner and with the effect provided in the Indenture.]

         [If the Security is an Original Issue Discount Security, insert -- If
an Event of Default with respect to Securities of this series shall occur and be
continuing, an amount of principal of the Securities of this series may be
declared due and payable in the manner and with the effect provided in the
Indenture. Such amount shall be equal to -- insert formula for determining the
amount. Upon payment (i) of the amount of principal so declared due and payable
and (ii) of interest on any overdue principal, premium and interest (in each
case to the extent that the payment of such interest shall be legally
enforceable), all of the Company's obligations in respect of the payment of the
principal of and premium and interest, if any, on the Securities of this series
shall terminate.]

         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 Securities of each series 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 Securities at
the time Outstanding of each series to be affected. The Indenture also contains
provisions permitting the Holders of specified percentages in principal amount
of the Securities of each series at the time Outstanding, on behalf of the
Holders of all Securities of such series, 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 by the Holder of
this Security shall be conclusive and binding upon such Holder and upon all
future Holders of this Security and of any Security issued upon the registration
of transfer hereof or in exchange herefor or in lieu hereof, whether or not
notation of such consent or waiver is made upon this Security.

         No reference herein to the Indenture and no provision of this Security
or of the Indenture shall alter or impair the obligation of the Company, which
is absolute and unconditional, to pay the principal of and any premium and
interest on this Security at the times, place and rate, and in



<PAGE>   27
                                                                              19

the coin or currency, herein prescribed. [If applicable, insert - or to
convert this Security as provided in the Indenture.]

         As provided in the Indenture and subject to certain limitations therein
set forth, the transfer of this Security is registrable in the Security
Register, upon surrender of this Security for registration of transfer at the
office or agency of the Company in any place where the principal of and any
premium and interest on this Security are payable, duly endorsed by, or
accompanied by a written instrument of transfer in form satisfactory to the
Company and the Security Registrar duly executed by, the Holder hereof or his
attorney duly authorized in writing, and thereupon one or more new Securities of
this series and of like tenor, of authorized denominations and for the same
aggregate principal amount, will be issued to the designated transferee or
transferees.

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

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

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

         All terms used in this Security which are defined in the Indenture
shall have the meanings assigned to them in the Indenture.

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

SECTION 2.04. Form of Legend for Global Securities.

         Unless otherwise specified as contemplated by Section 3.01 for the
Securities evidenced thereby, every Global Security authenticated and delivered
hereunder shall bear a legend in substantially the following form:

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

SECTION 2.05. Form of Trustee's Certificate of Authentication.

         The Trustee's certificates of authentication shall be in substantially
the following form:
<PAGE>   28

                                                                             20
         This is one of the Securities of the series designated therein referred
to in the within-mentioned Indenture.



Dated:_____________



                                          THE BANK OF NEW YORK,
                                                As Trustee


                                          By ______________________
                                          Authorized Signatory



                                 ARTICLE THREE

                                 THE SECURITIES

SECTION 3.01. Amount Unlimited; Issuable in Series.

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

         The Securities may be issued in one or more series. There shall be
established in or pursuant to a Board Resolution and, subject to Section 3.03,
set forth, or determined in the manner provided, in an Officers' Certificate, or
established in one or more indentures supplemental hereto, prior to the issuance
of Securities of any series,

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

              (2) any limit upon the aggregate principal amount of the
         Securities of the series which may be authenticated and delivered under
         this Indenture (except for Securities authenticated and delivered upon
         registration of transfer of, or in exchange for, or in lieu of, other
         Securities of the series pursuant to Section 3.04, 3.05, 3.06, 9.06 or
         11.07 and except for any Securities which, pursuant to Section 3.03,
         are deemed never to have been authenticated and delivered hereunder);

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

              (4) the date or dates on which the principal of any Securities of
         the series is payable;
<PAGE>   29


                                                                             21

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

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

              (7) the period or periods within which, the price or prices at
         which and the terms and conditions upon which any Securities of the
         series may be redeemed, in whole or in part, at the option of the
         Company;

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

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

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

              (11) if other than the currency of the United States of America,
         the currency, currencies or currency units in which the principal of or
         any premium or interest on any Securities of the series shall be
         payable and the manner of determining the equivalent thereof in the
         currency of the United States of America for any purpose, including for
         purposes of the definition of "Outstanding" in Section 1.01;

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

              (13) if other than the entire principal amount thereof, the
         portion of the principal amount of any Securities of the series which
         shall be payable upon declaration of acceleration of the Maturity
         thereof pursuant to Section 5.02;

              (14) if the principal amount payable at the Stated Maturity of any
         Securities of the series will not be determinable as of any one or more
         dates prior to the Stated Maturity, the amount which shall be deemed to
         be the principal amount of such Securities as of any such date for any
         purpose thereunder or hereunder, including the principal amount thereof
         which shall be due and payable upon any Maturity other than the Stated
<PAGE>   30

                                                                             22

         Maturity or which shall be deemed to be Outstanding as of any date
         prior to the Stated Maturity (or, in any such case, the manner in which
         such amount deemed to be the principal amount shall be determined);

              (15) if applicable, that the Securities of the series, in whole or
         any specified part, shall be defeasible pursuant to Section 13.02 or
         Section 13.03 or both such Sections and, if other than by a Board
         Resolution, the manner in which any election by the Company to defease
         such Securities shall be evidenced;

              (16) if applicable, that any Securities of the series shall be
         issuable in whole or in part in the form of one or more Global
         Securities and, in such case, the respective Depositaries for such
         Global Securities, the form of any legend or legends which shall be
         borne by any such Global Security in addition to or in lieu of that set
         forth in Section 2.04 and any circumstances in addition to or in lieu
         of those set forth in Clause (2) of the last paragraph of Section 3.05
         in which any such Global Security may be exchanged in whole or in part
         for Securities registered, and any transfer of such Global Security in
         whole or in part may be registered, in the name or names of Persons
         other than the Depositary for such Global Security or a nominee
         thereof;

              (17) any addition to or change in the Events of Default which
         applies to any Securities of the series and any change in the right of
         the Trustee or the requisite Holders of such Securities to declare the
         principal amount thereof due and payable pursuant to Section 5.02;

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

              (19) if applicable, that the Securities of the series shall be
         convertible pursuant to Article Fifteen, and the Initial Conversion
         Price, the Initial Conversion Date, the Final Conversion Date and any
         other terms relating to the conversion of the Securities as provided
         herein; and

              (20) any other terms of the series (which terms shall not be
         inconsistent with the provisions of this Indenture, except as permitted
         by Section 9.01(5)).

         All Securities of any one series shall be substantially identical
except as to denomination and except as may otherwise be provided in or pursuant
to the Board Resolution referred to above and (subject to Section 3.03) set
forth, or determined in the manner provided, in the Officers' Certificate
referred to above or in any such indenture supplemental hereto. All securities
of any one series need not be issued at one time and, unless otherwise provided,
a series may be reopened for issuances of additional securities of such series.

         Unless otherwise specifically provided with respect to the Securities
of a series, at the option of the Company, interest on the Securities of any
series that bears interest may be paid by mailing a check to the address of the
person entitled thereto as such address shall appear in the Security Register.

         If any of the terms of the series are established by action taken
pursuant to a Board Resolution, a copy of an appropriate record of such action
shall be certified by the Secretary or

<PAGE>   31
                                                                             23

an Assistant Secretary of the Company and delivered to the Trustee at or prior
to the delivery of the Officers' Certificate setting forth the terms of the
series.

SECTION 3.02. Denominations.

         The Securities of each series shall be issuable only in registered form
without coupons and only in such denominations as shall be specified as
contemplated by Section 3.01. In the absence of any such specified denomination
with respect to the Securities of any series, the Securities of such series
shall be issuable in denominations of $1,000 and any integral multiple thereof.

SECTION 3.03. Execution, Authentication, Delivery and Dating.

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

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

         At any time and from time to time after the execution and delivery of
this Indenture, the Company may deliver Securities of any series executed by the
Company to the Trustee for authentication, together with a Company Order for the
authentication and delivery of such Securities, and the Trustee in accordance
with the Company Order shall authenticate and deliver such Securities. If the
form or terms of the Securities of the series have been established by or
pursuant to one or more Board Resolutions as permitted by Sections 2.01 and
3.01, in authenticating such Securities, and accepting the additional
responsibilities under this Indenture in relation to such Securities, the
Trustee shall be entitled to receive, and (subject to Section 6.01) shall be
fully protected in relying upon, an Opinion of Counsel stating,

              (1) if the form of such Securities has been established by or
         pursuant to Board Resolution as permitted by Section 2.01, that such
         form has been established in conformity with the provisions of this
         Indenture;

              (2) if the terms of such Securities have been established by or
         pursuant to Board Resolution as permitted by Section 3.01, that such
         terms have been established in conformity with the provisions of this
         Indenture;

              (3) that such Securities, when authenticated and delivered by the
         Trustee and issued by the Company in the manner and subject to any
         conditions specified in such Opinion of Counsel, will constitute valid
         and legally binding obligations of the Company enforceable in
         accordance with their terms, subject to bankruptcy, insolvency,
         fraudulent transfer, reorganization, moratorium and similar laws of
         general applicability relating to or affecting creditors' rights and to
         general equity principles; and
<PAGE>   32

                                                                             24

              (4) that all laws and requirements in respect of the execution and
         delivery by the Company of such Securities have been complied with.

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

         Notwithstanding the provisions of Section 3.01 and of the preceding
paragraph, if all Securities of a series are not to be originally issued at one
time, it shall not be necessary to deliver the Officers' Certificate otherwise
required pursuant to Section 3.01 or the Company Order and Opinion of Counsel
otherwise required pursuant to such preceding paragraph at or prior to the
authentication of each Security of such series if such documents are delivered
at or prior to the authentication upon original issuance of the first Security
of such series to be issued.

         Each Security shall be dated the date of its authentication.

         No Security shall be entitled to any benefit under this Indenture or be
valid or obligatory for any purpose unless there appears on such Security a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by manual signature, and such certificate upon any
Security shall be conclusive evidence, and the only evidence, that such Security
has been duly authenticated and delivered hereunder. Notwithstanding the
foregoing, if any Security shall have been authenticated and delivered hereunder
but never issued and sold by the Company, and the Company shall deliver such
Security to the Trustee for cancellation as provided in Section 3.09, for all
purposes of this Indenture such Security shall be deemed never to have been
authenticated and delivered hereunder and shall never be entitled to the
benefits of this Indenture.

SECTION 3.04. Temporary Securities.

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

         If temporary Securities of any series are issued, the Company will
cause definitive Securities of that series to be prepared without unreasonable
delay. After the preparation of definitive Securities of such series, the
temporary Securities of such series shall be exchangeable for definitive
Securities of such series upon surrender of the temporary Securities of such
series at the office or agency of the Company in a Place of Payment for that
series, without charge to the Holder. Upon surrender for cancellation of any one
or more temporary Securities of any series, the Company shall execute and the
Trustee shall authenticate and deliver in exchange therefor one or more
definitive Securities of the same series, of any authorized denominations and of
like tenor and aggregate principal amount. Until so exchanged, the temporary
Securities of any series shall in all respects be entitled to the same benefits
under this Indenture as definitive Securities of such series and tenor.
<PAGE>   33


                                                                             25

SECTION 3.05. Registration; Registration of Transfer and Exchange.

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

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

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

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

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

         No service charge shall be made for any registration of transfer or
exchange of Securities, but the Company may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection
with any registration of transfer or exchange of Securities, other than
exchanges pursuant to Section 3.04, 9.06 or 11.07 not involving any transfer.

         If the Securities of any series (or of any series and specified tenor)
are to be redeemed in part, the Company shall not be required (A) to issue,
register the transfer of or exchange any Securities of that series (or of that
series and specified tenor, as the case may be) during a period beginning at the
opening of business 15 days before the day of the mailing of a notice of
redemption of any such Securities selected for redemption under Section 11.03
and ending at the close of business on the day of such mailing, or (B) to
register the transfer of or exchange any Security so selected for redemption in
whole or in part, except the unredeemed portion of any Security being redeemed
in part.

         The provisions of Clauses (1), (2), (3) and (4) below shall apply only
to Global Securities:
<PAGE>   34

                                                                              26

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

              (2) Notwithstanding any other provision in this Indenture, no
         Global Security may be exchanged in whole or in part for Securities
         registered, and no transfer of a Global Security in whole or in part
         may be registered, in the name of any Person other than the Depositary
         for such Global Security or a nominee thereof unless (A) such
         Depositary (i) has notified the Company that it is unwilling or unable
         to continue as Depositary for such Global Security or (ii) has ceased
         to be a clearing agency registered under the Exchange Act, (B) there
         shall have occurred and be continuing an Event of Default or an event
         which, with the giving of notice or lapse of time, or both, would
         constitute an Event of Default with respect to such Global Security and
         Holders of not less than a majority in principal amount of the series
         of Securities represented by such Global Security shall have made
         written request to the Trustee, (C) the Company executes and delivers
         to the Trustee a Company Order that such Global Security shall be so
         exchangeable, or (D) there shall exist such circumstances, if any, in
         addition to or in lieu of the foregoing as have been specified for this
         purpose as contemplated by Section 3.01.

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

              (4) Every Security authenticated and delivered upon registration
         of transfer of, or in exchange for or in lieu of, a Global Security or
         any portion thereof, whether pursuant to this Section, Section 3.04,
         3.06, 9.06 or 11.07 or otherwise, shall be authenticated and delivered
         in the form of, and shall be, a Global Security, unless such Security
         is registered in the name of a Person other than the Depositary for
         such Global Security or a nominee thereof.

SECTION 3.06. Mutilated, Destroyed, Lost and Stolen Securities.

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

         If there shall be delivered to the Company and the Trustee (i) evidence
to their satisfaction of the destruction, loss or theft of any Security and (ii)
such security or indemnity as may be required by them to save each of them and
any agent of either of them harmless, then, in the absence of notice to the
Company or the Trustee that such Security has been acquired by a bona fide
purchaser, the Company shall execute and the Trustee shall authenticate and
deliver, in lieu of any such destroyed, lost or stolen Security, a new Security
of the same series and of like tenor and principal amount and bearing a number
not contemporaneously outstanding.
<PAGE>   35

                                                                             27

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

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

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

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

SECTION 3.07. Payment of Interest; Interest Rights Preserved.

         Except as otherwise provided as contemplated by Section 3.01 with
respect to any series of Securities, interest on any Security which is payable,
and is punctually paid or duly provided for, on any Interest Payment Date shall
be paid to the Person in whose name that Security (or one or more Predecessor
Securities) is registered at the close of business on the Regular Record Date
for such interest.

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

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

<PAGE>   36
                                                                             28

         the proposed payment of such Defaulted Interest and the Special Record
         Date therefor to be given to each Holder of Securities of such series
         in the manner set forth in Section 1.06, not less than 10 days prior to
         such Special Record Date. Notice of the proposed payment of such
         Defaulted Interest and the Special Record Date therefor having been so
         mailed, such Defaulted Interest shall be paid to the Persons in whose
         names the Securities of such series (or their respective Predecessor
         Securities) are registered at the close of business on such Special
         Record Date and shall no longer be payable pursuant to the following
         Clause (2).

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

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

SECTION 3.08. Persons Deemed Owners.

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

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

         No holder of any beneficial interest in any Global Security held on
such holder's behalf by a Depositary shall have any rights under this Indenture
with respect to such Global Security, and such Depositary may be treated by the
Company, the Trustee, and any agent of the Company or the Trustee as the owner
of such Global Security for all purposes whatsoever. Notwithstanding the
foregoing, nothing herein shall impair, as between a Depositary and such holders
of beneficial interests, the operation of customary practices governing the
exercise of the rights of the Depositary as Holder of any Security.
<PAGE>   37
                                                                             29

SECTION 3.09. Cancellation.

         All Securities surrendered for payment, redemption, registration of
transfer or exchange or conversion or for credit against any sinking fund
payment shall, if surrendered to any Person other than the Trustee, be delivered
to the Trustee and shall be promptly cancelled by it. The Company may at any
time deliver to the Trustee for cancellation any Securities previously
authenticated and delivered hereunder which the Company may have acquired in any
manner whatsoever, and may deliver to the Trustee (or to any other Person for
delivery to the Trustee) for cancellation any Securities previously
authenticated hereunder which the Company has not issued and sold, and all
Securities so delivered shall be promptly cancelled by the Trustee. No
Securities shall be authenticated in lieu of or in exchange for any Securities
cancelled as provided in this Section, except as expressly permitted by this
Indenture. All cancelled Securities held by the Trustee shall be disposed of by
the Trustee in accordance with its customary procedures.

SECTION 3.10. Computation of Interest.

         Except as otherwise specified as contemplated by Section 3.01 for
Securities of any series, interest on the Securities of each series shall be
computed on the basis of a 360-day year of twelve 30-day months.

SECTION 3.11. CUSIP Numbers.

         The Company, in issuing the Securities, may use "CUSIP" numbers (if
then generally in use) and, if so, the Trustee shall use "CUSIP" numbers in
notice 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 numbers
either as printed on the Securities or as contained in any notice of a
redemption and that reliance may be placed only on the other identification
numbers printed on the Securities, and any such redemption shall not be affected
by any defect in or omission of such numbers. The Company will promptly notify
the Trustee of any change in the "CUSIP" numbers.

                                  ARTICLE FOUR

                           SATISFACTION AND DISCHARGE

SECTION 4.01. Satisfaction and Discharge of Indenture.

         This Indenture shall upon Company Request cease to be of further effect
(except as to any surviving rights of conversion, registration of transfer or
exchange of Securities herein expressly provided for), and the Trustee, at the
expense of the Company, shall execute proper instruments acknowledging
satisfaction and discharge of this Indenture, when

              (1) either

                   (A) all Securities theretofore authenticated and delivered
              (other than (i) Securities which have been destroyed, lost or
              stolen and which have been replaced or paid as provided in Section
              3.06 and (ii) Securities for whose payment money has theretofore
              been deposited in trust or segregated and held in trust by
<PAGE>   38

                                                                             30

              the Company and thereafter repaid to the Company or discharged
              from such trust, as provided in Section 10.03) have been delivered
              to the Trustee for cancellation; or

                   (B) all such Securities not theretofore delivered to the
              Trustee for cancellation

                       (i)   have become due and payable, or

                       (ii)  will become due and payable at their Stated
                             Maturity within one year, or

                       (iii) are to be called for redemption within one year
                             under arrangements satisfactory to the Trustee for
                             the giving of notice of redemption by the Trustee
                             in the name, and at the expense, of the Company,

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

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

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

         Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Company to the Trustee under Section 6.07, the obligations of
the Company to any Authenticating Agent under Section 6.14 and, if money shall
have been deposited with the Trustee pursuant to subclause (B) of Clause (1) of
this Section, the obligations of the Trustee under Section 4.02 and the last
paragraph of Section 10.03 shall survive.

SECTION 4.02. Application of Trust Money.

         Subject to the provisions of the last paragraph of Section 10.03, all
money deposited with the Trustee pursuant to Section 4.01 shall be held in trust
and applied by it, in accordance with the provisions of the Securities and this
Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the Persons entitled thereto, of the principal and any premium and
interest for whose payment such money has been deposited with the Trustee. All
monies deposited with the Trustee pursuant to Section 4.01 (and held by it or
the Paying Agent) for the payment of Securities subsequently converted shall be
returned to the Company upon Company Request.
<PAGE>   39

                                                                             31

                                  ARTICLE FIVE

                                    REMEDIES

SECTION 5.01. Events of Default.

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

              (1) default in the payment of any interest upon any Security of
         that series when it becomes due and payable, and continuance of such
         default for a period of 30 days; or

              (2) default in the payment of the principal of or any premium on
         any Security of that series at its Maturity; or

              (3) default in the deposit of any sinking fund payment, when and
         as due by the terms of a Security of that series and a continuance of
         such default for a period of 5 days; or

              (4) default in the performance, or breach, of any covenant or
         warranty of the Company in this Indenture (other than a covenant or
         warranty a default in whose performance or whose breach is elsewhere in
         this Section specifically dealt with or which has expressly been
         included in this Indenture solely for the benefit of series of
         Securities other than that series), and continuance of such default or
         breach for a period of 60 days after there has been given, by
         registered or certified mail, to the Company by the Trustee or to the
         Company and the Trustee by the Holders of not less than 25% in
         principal amount of the Outstanding Securities of that series a written
         notice specifying such default or breach and requiring it to be
         remedied and stating that such notice is a "Notice of Default"
         hereunder; or

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

              (6) the commencement by the Company of a voluntary case or
         proceeding under any applicable Federal or State bankruptcy,
         insolvency, reorganization or other similar law or of any other case or
         proceeding to be adjudicated a bankrupt or insolvent, or the consent by
         it to the entry of a decree or order for relief in respect of the
         Company in an
<PAGE>   40

                                                                             32

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

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

SECTION 5.02. Acceleration of Maturity; Rescission and Annulment.

         If an Event of Default specified in Section 5.01(5) or 5.01 (6) with
respect to Securities of any series at the time Outstanding occurs, the
principal amount of all the Securities of that series (or, if any Securities of
that series are Original Issue Discount Securities, such portion of the
principal amount of such Securities as may be specified by the terms thereof)
shall automatically, and without any declaration or other action on the part of
the Trustee or any Holder, become immediately due and payable.

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

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

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

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

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

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

and

              (2) all Events of Default with respect to Securities of that
         series, other than the non-payment of the principal of Securities of
         that series which have become due solely by such declaration of
         acceleration, have been cured or waived as provided in Section 5.13.
<PAGE>   41

                                                                             33

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

SECTION 5.03. Collection of Indebtedness and Suits for Enforcement by Trustee.

         The Company covenants that if

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

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

              (3) default is made in the making or satisfaction of any sinking
         fund payment or analogous obligation when the same becomes due pursuant
         to the terms of any Security and such default continues for 5 days,

the Company will, upon demand of the Trustee, pay to it, for the benefit of the
Holders of such Securities, the whole amount then due and payable on such
Securities for principal and any premium and interest and, to the extent that
payment of such interest shall be legally enforceable, interest on any overdue
principal and premium and on any overdue interest, at the rate or rates
prescribed therefor in such Securities, and, in addition thereto, such further
amount as shall be sufficient to cover the costs and expenses of collection,
including the reasonable compensation, expenses, disbursements and advances of
the Trustee, its agents and counsel.

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

         If an Event of Default with respect to Securities of any series occurs
and is continuing, the Trustee may in its discretion proceed to protect and
enforce its rights and the rights of the Holders of Securities of such series by
such appropriate judicial proceedings as the Trustee shall deem most 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 5.04. Trustee May File Proofs of Claim.

         In case of any judicial proceeding relative to the Company or any other
obligor upon the Securities or the property of the Company or such other obligor
or their creditors, the Trustee shall be entitled and empowered, by intervention
in such proceeding or otherwise, to take any and all actions authorized under
the such proceeding or otherwise, to take any and all actions authorized under
the Trust Indenture Act in order to have claims of the Holders and the Trustee
allowed in any such proceeding. In particular, the Trustee shall be authorized

               (i)  to file and prove a claim for the whole amount of principal
                    (and premium, if any) and interest owing and unpaid in
                    respect of the Securities in accordance with the terms

<PAGE>   42

                                                                             34

                    thereof and to file such other papers or documents as may be
                    necessary or advisable in order to have the claims of the
                    Trustee (including any claim for the reasonable
                    compensation, expense, disbursements and advances of the
                    Trustee, its agents and counsel) and of the Holders allowed
                    in such judicial proceeding, and

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

and any custodian, receiver, assignee, trustee, liquidator, sequestrator or
other similar official in any such judicial proceeding is hereby authorized by
each Holder to make such payments to the Trustee and, if the Trustee shall
consent to the making of such payments directly to the Holders, to pay to the
Trustee any amount due to the Trustee for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, and any other
amounts due the Trustee under Section 6.07.

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

SECTION 5.05. Trustee May Enforce Claims Without Possession of Securities.

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

SECTION 5.06. Application of Money Collected.

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

              First: To the payment of all amounts due the Trustee under Section
         6.07; and

              Second: Subject to Article Fourteen, to the payment of the amounts
         then due and unpaid for principal of and any premium and interest on
         the Securities in respect of which or for the benefit of which such
         money has been collected, ratably, without preference or


<PAGE>   43
                                                                             35

         priority of any kind, according to the amounts due and payable on
         such Securities for principal and any premium and interest,
         respectively.

SECTION 5.07. Limitation on Suits.

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

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

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

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

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

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

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

SECTION 5.08. Unconditional Right of Holders to Receive Principal, Premium and
              Interest or to Convert.

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

SECTION 5.09. Restoration of Rights and Remedies.

         If the Trustee or any Holder has instituted any proceeding to enforce
any right or remedy under this Indenture and such proceeding has been
discontinued or abandoned for any reason, or has been determined adversely to
the Trustee or to such Holder, then and in every such case, subject to any
determination in such proceeding, the Company, the Trustee and the Holders shall

<PAGE>   44
                                                                              36

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 with respect to the replacement or payment
of mutilated, destroyed, lost or stolen Securities in the last paragraph of
Section 3.06, no right or remedy herein conferred upon or reserved to the
Trustee or to the Holders is intended to be exclusive of any other right or
remedy, and every right and remedy shall, to the extent permitted by law, be
cumulative and in addition to every other right and remedy given hereunder or
now or hereafter existing at law or in equity or otherwise. The assertion or
employment of any right or remedy hereunder, or otherwise, shall not prevent the
concurrent assertion or employment of any other appropriate right or remedy.

SECTION 5.11. Delay or Omission Not Waiver.

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

SECTION 5.12. Control by Holders.

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

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

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

SECTION 5.13. Waiver of Past Defaults.

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

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

              (2) in respect of a covenant or provision hereof which under
         Article Nine cannot be modified or amended without the consent of the
         Holder of each Outstanding Security of such series affected.
<PAGE>   45

                                                                             37

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

SECTION 5.14. Undertaking for Costs.

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

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

                                  ARTICLE SIX

                                  THE TRUSTEE

SECTION 6.01. Certain Duties and Responsibilities.

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

SECTION 6.02. Notice of Defaults.

         If a default occurs hereunder with respect to Securities of any series,
the Trustee shall give the Holders of Securities of such series notice of such
default as and to the extent provided by the Trust Indenture Act; provided,
however, that in the case of any default of the character specified in Section
5.01(4) with respect to Securities of such series, no such notice to Holders
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 with respect
to Securities of such series.
<PAGE>   46

                                                                             38

SECTION 6.03. Certain Rights of Trustee.

         Subject to the provisions of Section 6.01:

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

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

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

              (4) the Trustee may consult with counsel 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;

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

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

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

              (8) the Trustee shall not be liable for any action taken, suffered
         or omitted to be taken by it in good faith and reasonably believed by
         it to be authorized or within the discretion or rights or powers
         conferred upon it by this Indenture;
<PAGE>   47

                                                                             39

              (9) the Trustee shall not be deemed to have notice of any default
         or Event of Default unless a Responsible Officer of the Trustee has
         actual knowledge thereof of unless written notice of any event which is
         in fact such a default is received by the Trustee at the Corporate
         Trust Office of the Trustee, and such notice references the Securities
         and this Indenture, unless the Trustee has received notice of such
         default or Event of Default pursuant to Section 10.04 hereof;

              (10) the rights, privileges, protections, immunities and benefits
         given to the Trustee, including, without limitation, its right to be
         indemnified, are extended to, and shall be enforceable by, the Trustee
         in each of its capacities hereunder; and

              (11) the Trustee may request that the Company deliver an Officers'
         Certificate setting forth the names of individuals and/or titles of
         officers authorized at such time to take specified actions pursuant to
         this Indenture, which Officers' Certificate may be signed by any person
         authorized to sign an Officers' Certificate, including any person
         specified as so authorized in any such certificate previously delivered
         and not superseded.

SECTION 6.04. Not Responsible for Recitals or Issuance of Securities.

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

SECTION 6.05. May Hold Securities.

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

SECTION 6.06. Money Held in Trust.

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

SECTION 6.07. Compensation and Reimbursement.

              The Company agrees

              (1) to pay to the Trustee from time to time such compensation as
         shall be agreed in writing between the Company and the Trustee for all
         services rendered by it hereunder (which compensation shall not be
         limited by any provision of law in regard to the compensation of a
         trustee of an express trust);
<PAGE>   48
                                                                             40

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

              (3) to indemnify each of the Trustee and any predecessor Trustee
         for, and to hold it harmless against, any and all loss, liability,
         damage, claim or expense, including taxes (other than taxes based on
         the income of the Trustee) incurred without negligence or bad faith on
         its part, arising out of or in connection with the acceptance or
         administration of the trust or trusts hereunder, including the costs
         and expenses of defending itself against any claim (whether against the
         Company, a Holder or any other Person) or liability in connection with
         the exercise or performance of any of its powers or duties hereunder.

         The Trustee shall have a lien prior to the Securities as to all
property and funds held by it hereunder for any amount owing it or any
predecessor Trustee pursuant to this Section 6.07, except with respect to funds
held in trust for the benefit of the Holders of particular Securities.

         When the Trustee incurs expenses or renders services in connection with
an Event of Default specified in Section 5.01(5) or Section 5.01(6), the
expenses (including the reasonable charges and expenses of its counsel) and the
compensation for the services are intended to constitute expenses of
administration under any applicable Federal or State bankruptcy, insolvency or
other similar law.

         The provisions of this Section shall survive the termination of this
Indenture.

SECTION 6.08. Conflicting Interests.

         If the Trustee has or shall acquire a conflicting interest within the
meaning of the Trust Indenture Act, the Trustee shall either eliminate such
interest or resign, to the extent and in the manner provided by, and subject to
the provisions of, the Trust Indenture Act and this Indenture.

SECTION 6.09. Corporate Trustee Required; Eligibility.

         There shall at all times be one (and only one) Trustee hereunder with
respect to the Securities of each series, which may be Trustee hereunder for
Securities of one or more other series. Each Trustee shall be a Person that is
eligible pursuant to the Trust Indenture Act to act as such, and has a combined
capital and surplus of at least $50,000,000 and has its Corporate Trust Office
in the Borough of Manhattan, The City of New York. If any such Person publishes
reports of condition at least annually, pursuant to law or to the requirements
of its supervising or examining authority, then for the purposes of this Section
and to the extent permitted by the Trust Indenture Act, the combined capital and
surplus of such Person shall be deemed to be its combined capital and surplus as
set forth in its most recent report of condition so published. If at any time
the Trustee with respect to the Securities of any series shall cease to be
eligible in accordance with the provisions of this Section, it shall resign
immediately in the manner and with the effect hereinafter specified in this
Article.
<PAGE>   49

                                                                             41

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 in
         accordance with the applicable requirements of Section 6.11.

              (b) The Trustee may resign at any time with respect to the
         Securities of one or more series by giving written notice thereof to
         the Company. If the instrument of acceptance by a successor Trustee
         required by Section 6.11 shall not have been delivered to the Trustee
         within 30 days after the giving of such notice of resignation, the
         resigning Trustee may petition, at the expense of the Company, any
         court of competent jurisdiction for the appointment of a successor
         Trustee with respect to the Securities of such series.

              (c) The Trustee may be removed at any time with respect to the
         Securities of any series by Act of the Holders of a majority in
         principal amount of the Outstanding Securities of such series,
         delivered to the Trustee and to the Company. If the 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 removal, the
         Trustee being removed may petition, at the expense of the Company, any
         court of competent jurisdiction for the appointment of a successor
         Trustee with respect to the Securities of such series.

              (d) If at any time:

              (1) the Trustee shall fail to comply with Section 6.08 after
         written request therefor by the Company or by any Holder who has been a
         bona fide Holder of a Security for at least six months, or

              (2) the Trustee shall cease to be eligible under Section 6.09 and
         shall fail to resign after written request therefor by the Company or
         by any such Holder, or

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

         then, in any such case, (A) the Company by a Board Resolution may
         remove the Trustee with respect to all Securities, or (B) subject to
         Section 5.14, any Holder who has been a bona fide Holder of a Security
         for at least six months may, on behalf of himself and all others
         similarly situated, petition any court of competent jurisdiction for
         the removal of the Trustee with respect to all Securities and the
         appointment of a successor Trustee or Trustees.

              (e) If the Trustee shall resign, be removed or become incapable of
         acting, or if a vacancy shall occur in the office of Trustee for any
         cause, with respect to the Securities of one or more series, the
         Company, by a Board Resolution, shall promptly appoint a successor
         Trustee or Trustees with respect to the Securities of that or those
         series (it being understood that any such successor Trustee may be
         appointed with respect to the Securities of one or more or all of such
         series and that at any time there shall be only one



<PAGE>   50
                                                                              42

         Trustee with respect to the Securities of any particular series) and
         shall comply with the applicable requirements of Section 6.11. If,
         within one year after such resignation, removal or incapability, or the
         occurrence of such vacancy, a successor Trustee with respect to the
         Securities of any series shall be appointed by Act of the Holders of a
         majority in principal amount of the Outstanding Securities of such
         series delivered to the Company and the retiring Trustee, the successor
         Trustee so appointed shall, forthwith upon its acceptance of such
         appointment in accordance with the applicable requirements of Section
         6.11, become the successor Trustee with respect to the Securities of
         such series and to that extent supersede the successor Trustee
         appointed by the Company. If no successor Trustee with respect to the
         Securities of any series shall have been so appointed by the Company or
         the Holders and accepted appointment in the manner required by Section
         6.11, any Holder who has been a bona fide Holder of a Security of such
         series for at least six months may, on behalf of himself and all others
         similarly situated, petition any court of competent jurisdiction for
         the appointment of a successor Trustee with respect to the Securities
         of such series.

              (f) The Company shall give notice of each resignation and each
         removal of the Trustee with respect to the Securities of any series and
         each appointment of a successor Trustee with respect to the Securities
         of any series to all Holders of Securities of such series in the manner
         provided in Section 1.06. Each notice shall include the name of the
         successor Trustee with respect to the Securities of such series and the
         address of its Corporate Trust Office.

SECTION 6.11. Acceptance of Appointment by Successor.

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

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



<PAGE>   51

                                                                             43

         shall add to or change any of the provisions of this Indenture as shall
         be necessary to provide for or facilitate the administration of the
         trusts hereunder by more than one Trustee, it being understood that
         nothing herein or in such supplemental indenture shall constitute such
         Trustees co-trustees of the same trust and that each such Trustee shall
         be trustee of a trust or trusts hereunder separate and apart from any
         trust or trusts hereunder administered by any other such Trustee; and
         upon the execution and delivery of such supplemental indenture the
         resignation or removal of the retiring Trustee shall become effective
         to the extent provided therein and each such successor Trustee, without
         any further act, deed or conveyance, shall become vested with all the
         rights, powers, trusts and duties of the retiring Trustee with respect
         to the Securities of that or those series to which the appointment of
         such successor Trustee relates; but, on request of the Company or any
         successor Trustee, such retiring Trustee shall duly assign, transfer
         and deliver to such successor Trustee all property and money held by
         such retiring Trustee hereunder with respect to the Securities of that
         or those series to which the appointment of such successor Trustee
         relates.

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

              (d) 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 the corporate trust business
of the Trustee, shall be the successor 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 Securities shall have been authenticated,
but not delivered, by the Trustee then in office, any successor by merger,
conversion or consolidation to such authenticating Trustee may adopt such
authentication and deliver the Securities so authenticated with the same effect
as if such successor Trustee had itself authenticated such Securities.

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

SECTION 6.14. Appointment of Authenticating Agent.

         The Trustee may appoint an Authenticating Agent or Agents with respect
to one or more series of Securities which shall be authorized to act on behalf
of the Trustee to authenticate Securities of such series issued upon original
issue and upon exchange, registration of transfer, partial conversion or partial
redemption thereof or pursuant to Section 3.06, and Securities so
<PAGE>   52
                                                                             44

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

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

         An Authenticating Agent may resign at any time by giving written notice
thereof to the Trustee and to the Company. The Trustee may at any time terminate
the agency of an Authenticating Agent by giving written notice thereof to such
Authenticating Agent and to the Company. Upon receiving such a notice of
resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent which shall be acceptable to the Company and shall give notice of such
appointment in the manner provided in Section 1.06 to all Holders of Securities
of the series with respect to which such Authenticating Agent will serve. Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, with like effect as if originally named as an Authenticating Agent.
No successor Authenticating Agent shall be appointed unless eligible under the
provisions of this Section.

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

         If an appointment with respect to one or more series is made pursuant
to this Section, the Securities of such series may have endorsed thereon, in
addition to the Trustee's certificate of authentication, an alternative
certificate of authentication in the following form:
<PAGE>   53

                                                                             45

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

                                          THE BANK OF NEW YORK,
                                               As Trustee



                                          By________________________,
                                             As Authenticating Agent


                                          By________________________
                                               Authorized Officer

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                                                                             46

                                 ARTICLE SEVEN

                HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

SECTION 7.01. Company to Furnish Trustee Names and Addresses of Holders.

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

              (1) semi-annually, not later than 10 calendar days after each
         Regular Record Date in each year, a list for each series of Securities,
         in such form as the Trustee may reasonably require, of the names and
         addresses of the Holders of Securities of each series as of the
         preceding Regular Record Date, and

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

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

SECTION 7.02. Preservation of Information; Communications to Holders.

         The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in Section 7.01 and the names and
addresses of Holders received by the Trustee in its capacity as Security
Registrar. The Trustee may destroy any list furnished to it as provided in
Section 7.01 upon receipt of a new list so furnished.

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

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

SECTION 7.03. Reports by Trustee.

              (a) The Trustee shall transmit to Holders such reports concerning
         the Trustee and its actions under this Indenture as may be required
         pursuant to the Trust Indenture Act at the times and in the manner
         provided pursuant thereto. To the extent that any such report is
         required by the Trust Indenture Act with respect to any 12 month
         period, such report shall cover the 12 month period ending July 15 and
         shall be transmitted by the next succeeding September 15.

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


<PAGE>   55

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         Trustee when any Securities are listed on any stock exchange and of any
         delisting thereof.

SECTION 7.04. Reports by Company.

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

         Delivery of such reports, information and documents to the Trustee is
for informational purposes only and the Trustee's receipt of such shall not
constitute constructive notice of any information contained therein or
determinable from information contained therein, including the Company's
compliance with any of its covenants hereunder (as to which the Trustee is
entitled to rely exclusively on Officers' Certificates).

                                 ARTICLE EIGHT

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

SECTION 8.01. Company May Consolidate, Etc., Only on Certain Terms.

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

              (1) in case the Company shall consolidate with or merge into
         another Person or convey, transfer or lease its properties and assets
         substantially as an entirety to any Person, the Person formed by such
         consolidation or into which the Company is merged or the Person which
         acquires by conveyance or transfer, or which leases, the properties and
         assets of the Company substantially as an entirety shall be a
         corporation, partnership or trust, shall be organized and validly
         existing under the laws of the United States of America, any State
         thereof or the District of Columbia and shall expressly assume, by an
         indenture supplemental hereto, executed and delivered to the Trustee,
         in form satisfactory to the Trustee, the due and punctual payment of
         the principal of and any premium and interest on all the Securities and
         the performance or observance of every covenant of this Indenture on
         the part of the Company to be performed or observed and, if applicable,
         shall have provided for conversion rights in accordance with Section
         15.11;

              (2) immediately after giving effect to such transaction and
         treating any indebtedness which becomes an obligation of the Company or
         any Subsidiary as a result of such transaction as having been incurred
         by the Company or such Subsidiary at the time of such transaction, no
         Event of Default, and no event which, after notice or lapse of time or
         both, would become an Event of Default, shall have happened and be
         continuing; and
<PAGE>   56

                                                                             48

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

SECTION 8.02. Successor Substituted.

         Upon any consolidation of the Company with, or merger of the Company
into, any other Person or any conveyance, transfer or lease of the properties
and assets of the Company substantially as an entirety in accordance with
Section 8.01, the successor Person formed by such consolidation or into which
the Company is merged or to which such conveyance, transfer or lease is made
shall succeed to, and be substituted for, and may exercise every right and power
of, the Company under this Indenture with the same effect as if such successor
Person had been named as the Company herein, and thereafter, except in the case
of a lease, the predecessor Person shall be relieved of all obligations and
covenants under this Indenture and the Securities.

                                  ARTICLE NINE

                             SUPPLEMENTAL INDENTURES

SECTION 9.01. Supplemental Indentures Without Consent of Holders.

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

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

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

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

              (4) to add to or change any of the provisions of this Indenture to
         such extent as shall be necessary to permit or facilitate the issuance
         of Securities in bearer form, registrable or not registrable as to
         principal, and with or without interest coupons, or to permit or
         facilitate the issuance of Securities in uncertificated form; or
<PAGE>   57

                                                                             49

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

              (6) to secure the Securities; or

              (7) to establish the form or terms of Securities of any series as
         permitted by Sections 2.01 and 3.01; or

              (8) to evidence and provide for the acceptance of appointment
         hereunder by a successor Trustee with respect to the Securities of one
         or more series and to add to or change any of the provisions of this
         Indenture as shall be necessary to provide for or facilitate the
         administration of the trusts hereunder by more than one Trustee,
         pursuant to the requirements of Section 6.11;

              (9) to make provision with respect to the conversion rights of
         Holders pursuant to the requirements of Section 15.12, if applicable;
         or

              (10) to cure any ambiguity, to correct or supplement any provision
         herein which may be defective or inconsistent with any other provision
         herein, or to make any other provisions with respect to matters or
         questions arising under this Indenture, provided that such action
         pursuant to this clause (10) shall not adversely affect the interests
         of the Holders of Securities of any series in any material respect.

SECTION 9.02. Supplemental Indentures with Consent of Holders.

         With the consent of the Holders of not less than a majority in
principal amount of the Outstanding Securities of each series affected by such
supplemental indenture, by Act of said Holders delivered to the Company and the
Trustee, the Company, when authorized by a Board Resolution, and the Trustee may
enter into an indenture or indentures supplemental hereto for the purpose of
adding any provisions to or changing in any manner or eliminating any of the
provisions of this Indenture or of modifying in any manner the rights of the
Holders of Securities of such series under this Indenture; provided, however,
that no such supplemental indenture shall, without the consent of the Holder of
each Outstanding Security affected thereby,

              (1) change the Stated Maturity of the principal of, or any
         installment of principal of or interest on, any Security, or reduce the
         principal amount thereof or the rate of interest thereon or any premium
         payable upon the redemption thereof, or reduce the amount of the
         principal of an Original Issue Discount Security or any other Security
         which would be due and payable upon a declaration of acceleration of
         the Maturity thereof pursuant to Section 5.02, or change any Place of
         Payment where, or the coin or currency in which, any Security or any
         premium or interest thereon is payable, or impair the right to
         institute suit for the enforcement of any such payment on or after the
         Stated Maturity thereof (or, in the case of redemption, on or after the
         Redemption Date), or modify the provisions of this Indenture with
         respect to the subordination of the Securities



<PAGE>   58
                                                                             50

         in a manner adverse to the Holders, or adversely affect the right to
         convert any Security as provided in Article Fifteen (except as
         permitted by Section 9.01(9), or

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

              (3) modify any of the provisions of this Section, Section 5.13 or
         Section 10.08, except to increase any such percentage or to provide
         that certain other provisions of this Indenture cannot be modified or
         waived without the consent of the Holder of each Outstanding Security
         affected thereby; provided, however, that this clause shall not be
         deemed to require the consent of any Holder with respect to changes in
         the references to "the Trustee" and concomitant changes in this Section
         and Section 10.08, or the deletion of this proviso, in accordance with
         the requirements of Sections 6.11 and 9.01(8).

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

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

SECTION 9.03. Execution of Supplemental Indentures.

         In executing, or accepting the additional trusts created by, any
supplemental indenture permitted by this Article or the modifications thereby of
the trusts created by this Indenture, the Trustee shall be entitled to receive,
and (subject to Section 6.01) shall be fully protected in relying upon, an
Officer's Certificate and an Opinion of Counsel stating that the execution of
such supplemental indenture is authorized or permitted by this Indenture. The
Trustee may, but shall not be obligated to, enter into any such supplemental
indenture which affects the Trustee's own rights, duties or immunities under
this Indenture or otherwise.

SECTION 9.04. Effect of Supplemental Indentures.

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

SECTION 9.05. Conformity with Trust Indenture Act.

         Every supplemental indenture executed pursuant to this Article shall
conform to the requirements of the Trust Indenture Act.
<PAGE>   59
                                                                             51

SECTION 9.06. Reference in Securities to Supplemental Indentures.

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

SECTION 9.07. Subordination Unimpaired.

         No provision in any supplemental indenture that affects the superior
position of the holders of Senior Indebtedness shall be effective against
holders of Senior Indebtedness. Notwithstanding any provision in this Indenture
or otherwise, the rights of Entitled Persons in respect of Other Financial
Obligations under this Indenture and otherwise in respect of the Securities or
any series of the Securities may, at any time and from time to time, be modified
in any respect or eliminated without the consent of any Entitled Person in
respect of Other Financial Obligations.

                                  ARTICLE TEN

                                   COVENANTS

SECTION 10.01. Payment of Principal, Premium and Interest.

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

SECTION 10.02. Maintenance of Office or Agency.

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

              (b) The Company may also from time to time designate one or more
         other offices or agencies where the Securities of one or more series
         may be presented or surrendered for any or all such purposes and may
         from time to time rescind such designations; provided, however, that no
         such designation or rescission shall in any



<PAGE>   60

                                                                             52

         manner relieve the Company of its obligation to maintain an office or
         agency in each Place of Payment for Securities of any series for such
         purposes. The Company will give prompt written notice to the Trustee of
         any such designation or rescission and of any change in the location of
         any such other office or agency.

SECTION 10.03. Money for Securities Payments to Be Held in Trust.

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

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

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

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

         Any money deposited with the Trustee or any Paying Agent, or then held
by the Company, in trust for the payment of the principal of or any premium or
interest on any Security of any series and remaining unclaimed for two years
after such principal, premium or interest has become due and payable shall be
paid to the Company on Company Request, or (if then held by the Company) shall
be discharged from such trust; and the Holder of such Security shall thereafter,
as an unsecured general creditor, look only to the Company for payment thereof,
and all liability of the Trustee or such Paying Agent with respect to such trust
money, and all liability of the Company as trustee thereof, shall thereupon
cease; provided, however, that the Trustee or such Paying Agent, before being
required to make any such repayment, may at the expense of the Company cause to
be published once, in a newspaper published in the English language, customarily
published on each Business Day and of general circulation in the Borough of
Manhattan, The City of New York, notice that such money remains unclaimed and
that, after a
<PAGE>   61

                                                                             53

date specified therein, which shall not be less than 30 days from the date of
such publication, any unclaimed balance of such money then remaining will be
repaid to the Company.

SECTION 10.04. Statement by Officers as to Default.

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

         The Company shall deliver to the Trustee, as soon as possible and in
any event within five days after the Company becomes aware of the occurrence of
any Event of Default or an event which, with notice or the lapse of time or
both, would constitute an Event of Default, an Officers' Certificate setting
forth the details of such Event of Default or default and the action which the
Company proposes to take with respect thereto.

SECTION 10.05. Existence.

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

SECTION 10.06. Maintenance of Properties

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


SECTION 10.07. Payment of Taxes and Other Claims.

         The Company will pay or discharge or cause to be paid or discharged,
before the same shall become delinquent, (1) all taxes, assessments and
governmental charges levied or imposed upon the Company or any Subsidiary or
upon the income, profits or property of the Company or any Subsidiary, and (2)
all lawful claims for labor, materials and supplies which, if unpaid, might by
law become a lien upon the property of the Company or any Subsidiary; provided,
however,
<PAGE>   62

                                                                             54

that the Company shall not be required to pay or discharge or cause to be paid
or discharged any such tax, assessment, charge or claim whose amount,
applicability or validity is being contested in good faith by appropriate
proceedings.

SECTION 10.08. Waiver of Certain Covenants.

         Except as otherwise specified as contemplated by Section 3.01 for
Securities of such series, the Company may, with respect to the Securities of
any series, omit in any particular instance to comply with any term, provision
or condition set forth in any covenant provided pursuant to Section 3.01(18),
9.01(2) or 9.01(7) for the benefit of the Holders of such series or in any of
Sections 10.05 to 10.07 inclusive if before the time for such compliance the
Holders of not less than a majority in principal amount of the Outstanding
Securities of such series shall, by Act of such Holders, either waive such
compliance in such instance or generally waive compliance with such term,
provision or condition, but no such waiver shall extend to or affect such term,
provision or condition except to the extent so expressly waived, and, until such
waiver shall become effective, the obligations of the Company and the duties of
the Trustee in respect of any such term, provision or condition shall remain in
full force and effect.

SECTION 10.09. Calculation of Original Issue Discount.

         The Company shall file with the Trustee promptly at the end of each
calendar year (i) a written notice specifying the amount of original issue
discount (including daily rates and accrual periods) accrued on Outstanding
Securities as of the end of such year and (ii) such other specific information
relating to such original issue discount as may then be relevant under the
Internal Revenue Code of 1986, as amended from time to time.

                                 ARTICLE ELEVEN

                            REDEMPTION OF SECURITIES

SECTION 11.01. Applicability of Article.

         Securities of any series which are redeemable before their Stated
Maturity shall be redeemable in accordance with their terms and (except as
otherwise specified as contemplated by Section 3.01 for such Securities) in
accordance with this Article.

SECTION 11.02. Election to Redeem; Notice to Trustee.

         The election of the Company to redeem any Securities shall be evidenced
by a Board Resolution or in another manner specified as contemplated by Section
3.01 for such Securities. In case of any redemption at the election of the
Company of the Securities of any series (including any such redemption affecting
only a single Security), the Company shall, at least 60 days prior to the
Redemption Date fixed by the Company (unless a shorter notice shall be
satisfactory to the Trustee), notify the Trustee of such Redemption Date, of the
principal amount of Securities of such series to be redeemed and, if applicable,
of the tenor of the Securities to be redeemed. In the case of any redemption of
Securities prior to the expiration of any restriction on such redemption
provided in the terms of such Securities or elsewhere in this Indenture, the
Company shall furnish the Trustee with an Officers' Certificate evidencing
compliance with such restriction.
<PAGE>   63

                                                                             55

SECTION 11.03. Selection by Trustee of Securities to Be Redeemed.

         If less than all the Securities of any series are to be redeemed
(unless all the Securities of a specified tenor are to be redeemed, the
particular Securities to be redeemed shall be selected not more than 60 days
prior to the Redemption Date by the Trustee, from the Outstanding Securities of
such series not previously called for redemption, by such method as the Trustee
shall deem fair and appropriate (but subject to compliance with the rules of any
securities exchange on which the securities of such series may be listed) and
which may provide for the selection for redemption of a portion of the principal
amount of any Security of such series, provided that the unredeemed portion of
the principal amount of any Security shall be in an authorized denomination
(which shall not be less than the minimum authorized denomination) for such
Security. If less than all the Securities of such series and of a specified
tenor are to be redeemed, the particular Securities to be redeemed shall be
selected not more than 60 days prior to the Redemption Date by the Trustee, from
the Outstanding Securities of such series and specified tenor not previously
called for redemption in accordance with the preceding sentence. If any
convertible Security selected for partial redemption is converted in part before
termination of the conversion right with respect to the portion of the Security
so selected, the converted portion of such Security shall be deemed (so far as
may be) to be the portion selected for redemption. Convertible Securities which
have been converted during a selection of Securities to be redeemed shall be
treated by the Trustee as Outstanding for the purposes of such selection.

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

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

SECTION 11.04. Notice of Redemption.

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

         All notices of redemption shall identify the Securities to be redeemed
(including CUSIP number) and shall state:

              (1) the Redemption Date,

              (2) the Redemption Price,

              (3) if less than all the Outstanding Securities of any series are
         to be redeemed, the identification (and, in the case of partial
         redemption of any such Securities, the principal amounts) of the
         particular Securities to be redeemed,
<PAGE>   64

                                                                             56

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

              (5) the conversion price, the date on which the right to convert
         the Securities to be redeemed will terminate and the place or places
         where such Securities may be surrendered for conversion,

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

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

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

SECTION 11.05. Deposit of Redemption Price.

         Prior to any Redemption Date, the Company shall deposit with the
Trustee or with a Paying Agent (or, if the Company is acting as its own Paying
Agent, segregate and hold in trust as provided in Section 10.03) an amount of
money sufficient to pay the Redemption Price of, and (except if the Redemption
Date shall be an Interest Payment Date) accrued interest on, all the Securities
which are to be redeemed on that date other than any convertible Securities
called for redemption on that date which have been converted prior to the date
of such deposit.

         If any convertible Security called for redemption is converted, any
money deposited with the Trustee or with any Paying Agent or so segregated and
held in trust for the redemption of such Security shall (subject to any right of
the Holder of such Security or any Predecessor Security to receive interest as
provided in the last paragraph of Section 3.07) be paid to the Company upon
Company Request or, if then held by the Company, shall be discharged from such
trust.

SECTION 11.06. Securities Payable on Redemption Date.

         Notice of redemption having been given as aforesaid, the Securities so
to be redeemed shall, on the Redemption Date, become due and payable at the
Redemption Price therein specified, and from and after such date (unless the
Company shall default in the payment of the Redemption Price and accrued
interest) such Securities shall cease to bear interest. Upon surrender of any
such Security for redemption in accordance with said notice, such Security shall
be paid by the Company at the Redemption Price, together with accrued interest
to the Redemption Date; provided, however, that, unless otherwise specified as
contemplated by Section 3.01, installments of interest whose Stated Maturity is
on or prior to the Redemption Date will be payable to the Holders of such
Securities, or one or more Predecessor Securities, registered as such at the
close of business on the relevant Record Dates according to their terms and the
provisions of Section 3.07.
<PAGE>   65

                                                                             57

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

SECTION 11.07. Securities Redeemed in Part.

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

                                 ARTICLE TWELVE

                                  SINKING FUNDS

SECTION 12.01. Applicability of Article.

         The provisions of this Article shall be applicable to any sinking fund
for the retirement of Securities of any series except as otherwise specified as
contemplated by Section 3.01 for such Securities.

         The minimum amount of any sinking fund payment provided for by the
terms of any Securities is herein referred to as a "mandatory sinking fund
payment", and any payment in excess of such minimum amount provided for by the
terms of such Securities is herein referred to as an "optional sinking fund
payment". If provided for by the terms of any Securities, the cash amount of any
sinking fund payment may be subject to reduction as provided in Section 12.02.
Each sinking fund payment shall be applied to the redemption of Securities as
provided for by the terms of such Securities.

SECTION 12.02. Satisfaction of Sinking Fund Payments with Securities.

         The Company (1) may deliver Outstanding Securities of a series (other
than any previously called for redemption) and (2) may apply as a credit
Securities of a series which have been converted pursuant to Article Fifteen or
which have been redeemed either at the election of the Company pursuant to the
terms of such Securities or through the application of permitted optional
sinking fund payments pursuant to the terms of such Securities, in each case in
satisfaction of all or any part of any sinking fund payment with respect to any
Securities of such series required to be made pursuant to the terms of such
Securities as and to the extent provided for by the terms of such Securities;
provided that the Securities to be so credited have not been previously so
credited. The Securities to be so credited shall be received and credited for
such purpose by the Trustee at the Redemption Price, as specified in the
Securities so to be redeemed, for redemption through operation of the sinking
fund and the amount of such sinking fund payment shall be reduced accordingly.
<PAGE>   66

                                                                             58

SECTION 12.03. Redemption of Securities for Sinking Fund.

         Not less than 60 days prior to each sinking fund payment date for any
Securities, the Company will deliver to the Trustee an Officers' Certificate
specifying the amount of the next ensuing sinking fund payment for such
Securities pursuant to the terms of such Securities, the portion thereof, if
any, which is to be satisfied by payment of cash and the portion thereof, if
any, which is to be satisfied by delivering and crediting Securities pursuant to
Section 12.02 and will also deliver to the Trustee any Securities to be so
delivered. Not less than 45 days prior to each such sinking fund payment date,
the Trustee shall select the Securities to be redeemed upon such sinking fund
payment date in the manner specified in Section 11.03 and cause notice of the
redemption thereof to be given in the name of and at the expense of the Company
in the manner provided in Section 11.04. Such notice having been duly given, the
redemption of such Securities shall be made upon the terms and in the manner
stated in Sections 11.06 and 11.07.

                                ARTICLE THIRTEEN

                       DEFEASANCE AND COVENANT DEFEASANCE

SECTION 13.01. Company's Option to Effect Defeasance or Covenant Defeasance.

         The Company may elect, at its option at any time, to have Section 13.02
or Section 13.03 applied to any Securities or any series of Securities, as the
case may be, designated pursuant to Section 3.01 as being defeasible pursuant to
such Section 13.02 or 13.03, in accordance with any applicable requirements
provided pursuant to Section 3.01 and upon compliance with the conditions set
forth below in this Article. Any such election shall be evidenced by a Board
Resolution or in another manner specified as contemplated by Section 3.01 for
such Securities.

SECTION 13.02. Defeasance and Discharge.

         Upon the Company's exercise of its option (if any) to have this Section
applied to any Securities or any series of Securities, as the case may be, the
Company shall be deemed to have been discharged from its obligations, and the
provisions of Article Fourteen shall cease to be effective, with respect to such
Securities as provided in this Section on and after the date the conditions set
forth in Section 13.04 are satisfied (hereinafter called "Defeasance"). For this
purpose, such Defeasance means that the Company shall be deemed to have paid and
discharged the entire indebtedness represented by such Securities and to have
satisfied all its other obligations under such Securities and this Indenture
insofar as such Securities are concerned (and the Trustee, at the expense of the
Company, shall execute proper instruments acknowledging the same), subject to
the following which shall survive until otherwise terminated or discharged
hereunder: (1) the rights of Holders of such Securities to receive, solely from
the trust fund described in Section 13.04 and as more fully set forth in such
Section, payments in respect of the principal of and any premium and interest on
such Securities when payments are due, (2) the Company's obligations with
respect to such Securities under Sections 3.04, 3.05, 3.06, 10.02 and 10.03, (3)
the rights, powers, trusts, duties and immunities of the Trustee hereunder and
(4) this Article. Subject to compliance with this Article, the Company may
exercise its option (if any) to have this Section applied to any Securities
notwithstanding the prior exercise of its option (if any) to have Section 13.03
applied to such Securities.
<PAGE>   67

                                                                             59

SECTION 13.03. Covenant Defeasance.

         Upon the Company's exercise of its option (if any) to have this Section
applied to any Securities or any series of Securities, as the case may be, (1)
the Company shall be released from its obligations under any Section applicable
to such Securities that are determined pursuant to Section 3.01 to be subject to
this provision), (2) the occurrence of any event specified in Sections 5.01(4)
(with respect to any Section applicable to such Securities that are determined
pursuant to Section 3.01 to be subject to this provision) shall be deemed not to
be or result in an Event of Default and (3) the provisions of Article Fourteen
shall cease to be effective, in each case with respect to such Securities as
provided in this Section on and after the date the conditions set forth in
Section 13.04 are satisfied (hereinafter called "Covenant Defeasance"). For this
purpose, such Covenant Defeasance means that, with respect to such Securities,
the Company may omit to comply with (and no Event of Default shall arise out of
such non-compliance) with and shall have no liability in respect of any term,
condition or limitation set forth in any such specified Section or Article,
whether directly or indirectly by reason of any reference elsewhere herein to
any such Section or Article or by reason of any reference in any such Section or
Article to any other provision herein or in any other document, but the
remainder of this Indenture and such Securities shall be unaffected thereby.

SECTION 13.04. Conditions to Defeasance or Covenant Defeasance.

         The following shall be the conditions to the application of Section
13.02 or Section 13.03 to any securities or any series of Securities, as the
case may be:

              (1) The Company shall irrevocably have deposited or caused to be
         deposited with the Trustee (or another trustee which satisfies the
         requirements contemplated by Section 6.09 and agrees to comply with the
         provisions of this Article applicable to it) as trust funds in trust
         for the purpose of making the following payments, specifically pledged
         as security for, and dedicated solely to, the benefits of the Holders
         of such Securities, (A) in the case of Securities denominated in a
         foreign currency, money in such foreign currency or Foreign Government
         Obligations of the foreign government or governments issuing such
         foreign currency which through the scheduled payment of principal and
         interest in respect thereof in accordance with their terms will
         provide, not later than one day before the due date of any payment,
         such foreign currency in an amount or (B) in the case of Securities
         denominated in U.S. dollars, U.S. dollars or U.S. Government
         Obligations which through the scheduled payment of principal and
         interest in respect thereof in accordance with their terms will
         provide, not later than one day before the due date of any payment,
         U.S. dollars in an amount, or (C) a combination of money and U.S.
         Government Obligations or Foreign Government Obligations (as
         applicable), in each case sufficient, in the opinion of a nationally
         recognized firm of independent public accountants expressed in a
         written certification thereof delivered to the Trustee, to pay and
         discharge, and which shall be applied by the Trustee (or any such other
         qualifying trustee) to pay and discharge, the principal of and any
         premium and interest on such Securities on the respective Stated
         Maturities, in accordance with the terms of this Indenture and such
         Securities. As used herein, "U.S. Government Obligation" means (x) any
         security which is (i) a direct obligation of the United States of
         America for the payment of which the full faith and credit of the
         United States of America is pledged or (ii) an obligation of a Person
         controlled or supervised by and acting as an agency or instrumentality
         of the United States of America the payment of
<PAGE>   68

                                                                             60

         which is unconditionally guaranteed as a full faith and credit
         obligation by the United States of America, which, in either case (i)
         or (ii), is not callable or redeemable at the option of the issuer
         thereof, and (y) any depositary receipt issued by a bank (as defined in
         Section 3(a)(2) of the Securities Act) as custodian with respect to any
         U.S. Government Obligation which is specified in Clause (x) above and
         held by such bank for the account of the holder of such depositary
         receipt, or with respect to any specific payment of principal of or
         interest on any U.S. Government Obligation which is so specified and
         held, provided that (except as required by law) such custodian is not
         authorized to make any deduction from the amount payable to the holder
         of such depositary receipt from any amount received by the custodian in
         respect of the U.S. Government Obligation or the specific payment of
         principal or interest evidenced by such depositary receipt. As used
         herein, "Foreign Government Obligation" means any security denominated
         in a foreign currency which is (i) a direct obligation of a foreign
         government or governments for the payment of which the full faith and
         credit of such foreign government or governments is pledged or (ii) an
         obligation of a Person controlled or supervised by and acting as an
         agency or instrumentality of such foreign government or governments the
         payment of which is unconditionally guaranteed as a full faith and
         credit obligation by such foreign government, which, in either case (i)
         or (ii) is not callable or redeemable at the option of the issuer
         thereof.

              (2) In the event of an election to have Section 13.02 apply to any
         Securities or any series of Securities, as the case may be, the Company
         shall have delivered to the Trustee an Opinion of Counsel stating that
         (x) the Company has received from, or there has been published by, the
         Internal Revenue Service a ruling or (y) since the date of this
         instrument, there has been a change in the applicable Federal income
         tax law, in either case (x) or (y) to the effect that, and based
         thereon such opinion shall confirm that, the Holders of such Securities
         will not recognize gain or loss for Federal income tax purposes as a
         result of the deposit, Defeasance and discharge to be effected with
         respect to such Securities and will be subject to Federal income tax on
         the same amount, in the same manner and at the same times as would be
         the case if such deposit, Defeasance and discharge were not to occur.

              (3) In the event of an election to have Section 13.03 apply to any
         Securities or any series of Securities, as the case may be, the Company
         shall have delivered to the Trustee an Opinion of Counsel to the effect
         that the Holders of such Securities will not recognize gain or loss for
         Federal income tax purposes as a result of the deposit and Covenant
         Defeasance to be effected with respect to such Securities and will be
         subject to Federal income tax on the same amount, in the same manner
         and at the same times as would be the case if such deposit and Covenant
         Defeasance were not to occur.

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

              (5) No event which is, or after notice or lapse of time or both
         would become, an Event of Default with respect to such Securities or
         any other Securities shall have occurred and be continuing (A) at the
         time of such deposit or, (B) with regard to any such event specified in
         Sections 5.01(5) and (6), at any time during the period ending on the
         123rd day after the date of such deposit or, if longer, ending on the
         day following the

<PAGE>   69

                                                                             61

         expiration of the longest preference period applicable to the Company
         in respect of such deposit (it being understood that the condition in
         this clause (B) is a condition subsequent and shall not be deemed
         satisfied until the expiration of such period).

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

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

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

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

SECTION 13.05. Deposited Money and U.S. Government Obligations to Be Held in
               Trust; Miscellaneous Provisions.

         Subject to the provisions of the last paragraph of Section 10.03, all
money, U.S. Government Obligations and Foreign Government Obligations (including
the proceeds thereof) deposited with the Trustee or other qualifying trustee
(solely for purposes of this Section and Section 13.06, the Trustee and any such
other trustee are referred to collectively as the "Trustee") pursuant to Section
13.04 in respect of any Securities shall be held in trust and applied by the
Trustee, in accordance with the provisions of such Securities and this
Indenture, to the payment, either directly or through any such Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the Holders of such Securities, of all sums due and to become due
thereon in respect of principal and any premium and interest, but money so held
in trust need not be segregated from other funds except to the extent required
by law. Money, U.S. Government Obligations and Foreign Government Obligations so
held in trust shall not be subject to the provisions of Article Fourteen.

         The Company shall pay and indemnify the Trustee against any tax, fee or
other charge imposed on or assessed against the U.S. Government Obligations or
the Foreign Government Obligations deposited pursuant to Section 13.04 or the
principal and interest received in respect thereof other than any such tax, fee
or other charge which by law is for the account of the Holders of Outstanding
Securities.

         Anything in this Article to the contrary notwithstanding, the Trustee
shall deliver or pay to the Company from time to time upon Company Request any
money or U.S. Government Obligations or the Foreign Government Obligations held
by it as provided in Section 13.04 with respect to any Securities which, in the
opinion of a nationally recognized firm of independent public accountants
expressed in a written certification thereof delivered to the Trustee, are in

<PAGE>   70

                                                                             62

excess of the amount thereof which would then be required to be deposited to
effect the Defeasance or Covenant Defeasance, as the case may be, with respect
to such Securities.

SECTION 13.06. Reinstatement.

         If the Trustee or the Paying Agent is unable to apply any money in
accordance with this Article with respect to any Securities by reason of any
order or judgment of any court or governmental authority enjoining, restraining
or otherwise prohibiting such application, then the obligations under this
Indenture and such Securities from which the Company has been discharged or
released pursuant to Section 13.02 or 13.03 shall be revived and reinstated as
though no deposit had occurred pursuant to this Article with respect to such
Securities, until such time as the Trustee or Paying Agent is permitted to apply
all money held in trust pursuant to Section 13.05 with respect to such
Securities in accordance with this Article; provided, however, that if the
Company makes any payment of principal of or any premium or interest on any such
Security following such reinstatement of its obligations, the Company shall be
subrogated to the rights (if any) of the Holders of such Securities to receive
such payment from the money so held in trust.

                                ARTICLE FOURTEEN

                           SUBORDINATION OF SECURITIES

SECTION 14.01. Securities Subordinate to Senior Indebtedness.

         The Company covenants and agrees, and each Holder of a Security, by his
acceptance thereof, likewise covenants and agrees, that, to the extent and in
the manner hereinafter set forth in this Article, the indebtedness represented
by the Securities and the payment of the principal of (and premium, of any) and
interest on each and all of the Securities are hereby expressly made subordinate
and subject in right of payment to the prior payment in full of all Senior
Indebtedness and, to the extent set forth in Section 14.15, of all Other
Financial Obligations.

SECTION 14.02. Payment Over of Proceeds Upon Dissolution, Etc.

         In the event of (a) any insolvency or bankruptcy case or proceeding, or
any receivership, liquidation, reorganization or other similar case or
proceeding in connection therewith, relative to the Company or to its creditors,
as such, or to its assets, or (b) any liquidation, dissolution or other winding
up of the Company, whether voluntary or involuntary and whether or not involving
insolvency or bankruptcy, or (c) any assignment for the benefit of creditors or
any other marshalling of assets and liabilities of the Company, then and in any
such event the holders of Senior Indebtedness shall be entitled to receive
payment in full of all amounts due or to become due on or in respect of all
Senior Indebtedness, or provision shall be made for such payment in money or
money's worth, before the Holders of the Securities are entitled to receive any
payment on account of principal of (or premium, if any) or interest on the
Securities, and to that end the holders of Senior Indebtedness shall be entitled
to receive, for application to the payment thereof, any payment or distribution
of any kind or character, whether in cash, property or securities, including any
such payment or distribution which may be payable or deliverable by reason of
the payment of any other indebtedness of the Company being subordinated to the
payment of the Securities, which may be payable or deliverable in respect of the
Securities in any such case, proceeding, dissolution, liquidation or other
winding up or event.
<PAGE>   71

                                                                             63

         In the event that, notwithstanding the foregoing provisions of this
Section, the Trustee or the Holder of any Security shall have received any
payment or distribution of assets of the Company of any kind or character,
whether in cash, property or securities, including any such payment or
distribution which may be payable or deliverable by reason of the payment of any
other indebtedness of the Company being subordinated to the payment of the
Securities, before all Senior Indebtedness is paid in full or payment thereof
provided for, and if such fact shall, at or prior to the time of such payment or
distribution, have been made known to the Trustee or, as the case may be, such
Holder, then and in such event such payment or distribution shall be paid over
or delivered forthwith to the trustee in bankruptcy, receiver, liquidating
trustee, custodian, assignee, agent or other Person making payment or
distribution of assets of the Company for application to the payment of all
Senior Indebtedness remaining unpaid, to the extent necessary to pay all Senior
Indebtedness in full, after giving effect to any concurrent payment or
distribution to or for the holders of Senior Indebtedness.

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

SECTION 14.03.  Prior Payment to Senior Indebtedness Upon Acceleration of
                Securities.

         In the event that any Securities are declared due and payable before
their Stated Maturity, then and in such event the holders of Senior Indebtedness
outstanding at the time such Securities become so due and payable shall be
entitled to receive payment in full of all amounts due or to become due on or in
respect of all Senior Indebtedness or provision shall be made for such payment
in money or money's worth, before the Holders of the Securities are entitled to
receive any payment (including any payment which may be payable by reason of the
payment of any other indebtedness of the Company being subordinated to the
payment of the Securities) by the Company on account of the principal of (or
premium, if any) or interest on the Securities or on account of the purchase or
other acquisition of Securities; provided, however, that nothing in this Section
shall prevent the satisfaction of any sinking fund payment in accordance with
Article Twelve by delivering and crediting pursuant to Section 12.02 Securities
which have been acquired (upon redemption or otherwise) prior to such
declaration of acceleration.

         In the event that, notwithstanding the foregoing, the Company shall
make any payment to the Trustee or the Holder of any Security prohibited by the
foregoing provisions of this Section, and if such fact shall, at or prior to the
time of such payment, have been made known to the
<PAGE>   72

                                                                             64

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 14.02 would be applicable.

SECTION 14.04. No Payment When Senior Indebtedness 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 any Senior
Indebtedness beyond any applicable grace period with respect thereto, or in the
event that any event of default with respect to any Senior Indebtedness shall
have occurred and be continuing permitting the holders of such Senior
Indebtedness (or a trustee on behalf of the holders thereof) to declare such
Senior Indebtedness due and payable prior to the date on which it would
otherwise have become due and payable, unless and until such event of default
shall have been cured or 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 event of default, then no payment (including any payment which may be payable
by reason of the payment of any other indebtedness of the Company being
subordinated to the payment of the Securities) shall be made by the Company on
account of principal of (or premium, if any) or interest on the Securities or on
account of the purchase or other acquisition of Securities; provided, however,
that nothing in this Section shall prevent the satisfaction of any sinking fund
payment in accordance with Article Twelve by delivering and crediting pursuant
to Section 12.02 Securities which have been acquired (upon redemption or
otherwise) prior to such default in payment or event of default.

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

         The provisions of this Section shall not apply to any payment with
respect to which Section 14.02 would be applicable.

SECTION 14.05. Payment Permitted in Certain Situations.

         Nothing contained in this Article or elsewhere in this Indenture or in
any of the Securities shall prevent (a) the Company, at any time except during
the pendency of any case, proceeding, dissolution, liquidation or other winding
up, assignment for the benefit of creditors or other marshalling of assets and
liabilities of the Company referred to in Section 14.02 or under the conditions
described in Section 14.03 or 14.04, from making payments at any time of
principal of (and premium, if any) or interest on the Securities or (b) 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
on the Securities of any series or the retention of such payment by the Holder,
if, at the time of such application by the Trustee, it did not have actual
knowledge that such payment would have been prohibited by the provisions of this
Article.
<PAGE>   73

                                                                             65

SECTION 14.06. Subrogation to Rights of Holders of Senior Indebtedness.

         Subject to the payment in full of all Senior Indebtedness, the Holders
of the Securities shall be subrogated to the extent of the payments or
distributions made to the holders of such Senior Indebtedness pursuant to the
provisions of this Article to the rights of the holders of such Senior
Indebtedness to receive payments and distributions of cash, property and
securities applicable to the Senior Indebtedness until the principal of (and
premium, if any) and interest on the Securities shall be paid in full. For
purposes of such subrogation, no payments or distributions to the holders of the
Senior Indebtedness of any cash, property or securities to which the Holders of
the Securities or the Trustee would be entitled except for the provisions of
this Article, and no payments over pursuant to the provisions of this Article to
the holders of Senior Indebtedness by Holders of the Securities or the Trustee,
shall, as among the Company, its creditors other than holders of Senior
Indebtedness and the Holders of the Securities, be deemed to be a payment or
distribution by the Company to or on account of the Senior Indebtedness.

SECTION 14.07. 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 Securities on the
one hand and the holders of Senior Indebtedness (and, in the case of Section
14.15, Entitled Persons in respect of Other Financial Obligations) on the other
hand. Nothing contained in this Article or elsewhere in this Indenture or in the
Securities is intended to or shall (a) impair, as among the Company, its
creditors other than holders of Senior Indebtedness and other than Entitled
Persons in respect of Other Financial Obligations and the Holders of the
Securities, the obligation of the Company, which is absolute and unconditional
(and which, subject to the rights under this Article of the holders of Senior
Indebtedness and Entitled Persons in respect of Other Financial Obligations, is
intended to rank equally with all other general obligations of the Company), to
pay to the Holders of the Securities the principal of (and premium, if any) and
interest on the Securities 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 Securities and creditors of the Company other than
the holders of Senior Indebtedness and Entitled Persons in respect of Other
Financial Obligations; or (c) prevent the Trustee or the Holder of any Security
from exercising all remedies otherwise permitted by applicable law upon default
under this Indenture, subject to the rights, if any, under this Article of the
holders of Senior Indebtedness and under Section 14.15 of Entitled Persons in
respect of Other Financial Obligations, to receive cash, property and securities
otherwise payable or deliverable to the Trustee or such Holder.

SECTION 14.08. Trustee to Effectuate Subordination.

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

SECTION 14.09. No Waiver of Subordination Provisions.

         No right of any present or future holder of any Senior Indebtedness to
enforce subordination as herein provided shall at any time in any way be
prejudiced or impaired by any
<PAGE>   74

                                                                             66

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 non-compliance by the Company
with the terms, provisions and covenants of this Indenture, regardless of any
knowledge thereof any such holder may have or be otherwise charged with.

         Without in any way limiting the generality of the foregoing paragraph,
the holders of Senior Indebtedness (and Entitled Persons in respect of Other
Financial Obligations) may, at any time and from time to time, without the
consent of or notice to the Trustee or the Holders of the Securities, without
incurring responsibility to the Holders of the Securities and without impairing
or releasing the subordination provided in this Article or the obligations
hereunder of the Holders of the Securities to the holders of Senior Indebtedness
and Entitled Persons, in respect of Other Financial Obligations, do any one or
more of the following: (i) change the manner, place or terms of payment or
extend the time of payment of, or renew or alter, Senior Indebtedness or Other
Financial Obligations, or otherwise amend or supplement in any manner Senior
Indebtedness or Other Financial Obligations or any instrument evidencing the
same or any agreement under which Senior Indebtedness is or Other Financial
Obligations are outstanding; (ii) sell, exchange, release or otherwise deal with
any property pledged, mortgaged or otherwise securing Senior Indebtedness or
Other Financial Obligations; (iii) release any Person liable in any manner for
the collection of Senior Indebtedness or Other Financial Obligations; and (iv)
exercise or refrain from exercising any rights against the Company and any other
Person.

SECTION 14.10. 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 Securities. 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 Securities, unless
and until the Trustee shall have received written notice thereof from the
Company or a holder of Senior Indebtedness or from any trustee therefor or from
any Entitled Persons in respect of Other Financial Obligations; and, prior to
the receipt of any such written notice, the Trustee, subject to the provisions
of Section 6.01, shall be entitled in all respects to assume that no such facts
exist; provided, however, that if the Trustee shall not have receive the notice
provided for in this Section at least two Business Days prior to the date upon
which by the terms hereof any money may become payable for any purpose
(including, without limitation, the payment of the principal (and premium, if
any) or interest on any security) then notwithstanding anything to the contrary
herein, the Trustee shall have full power and authority to receive such money
and to apply the same to the purpose for which such money was received and shall
not be affected by any notice to the contrary which may be received by it within
two Business Days prior to such date.

         Subject to the provisions of Section 6.01, the Trustee shall be
entitled to rely on the delivery to it of a written notice by a Person
representing himself to be a holder of Senior Indebtedness (or a trustee
therefor) or an Entitled Person in respect of Other Financial Obligations to
establish that such notice has been given by a holder of Senior Indebtedness (or
a trustee therefor) or an Entitled Person in respect of Other Financial
Obligations. In the event that the Trustee determines in good faith that further
evidence is required with respect to the right of any Person as a holder of
Senior Indebtedness or an Entitled Person in respect of Other Financial
Obligations to participate in any payment or distribution pursuant to this
Article, the Trustee may

<PAGE>   75

                                                                             67

request such Person to furnish evidence to the reasonable satisfaction of the
Trustee as to the amount of Senior Indebtedness or other Financial Obligations
held by such Person, the extent to which such Person is entitled to participate
in such payment or distribution and any other facts pertinent to the rights of
such Person under this Article, and if such evidence is not furnished, the
Trustee may defer any payment to such Person pending judicial determination as
to the right of such Person to receive such payment.

SECTION 14.11. Reliance on Judicial Order or Certificate of Liquidating Agent.

         Upon any payment or distribution of assets of the Company referred to
in this Article, the Trustee, subject to the provisions of Section 6.01, and the
Holders of the Securities shall be entitled to rely upon any order or decree
entered by any court of competent jurisdiction in which such insolvency,
bankruptcy, receivership, liquidation, reorganization, dissolution, winding up
or similar case or proceeding is pending, or a certificate of the trustee in
bankruptcy, receiver, liquidating trustee, custodian, assignee for the benefit
of creditors, agent or other Person making such payment or distribution,
delivered to the Trustee or to the Holders of Securities, for the purpose of
ascertaining the Persons entitled to participate in such payment or
distribution, the holders of Senior Indebtedness and other indebtedness of the
Company and the Entitled Persons in respect of Other Financial Obligations, 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 14.12. Trustee Not Fiduciary for Holders of Senior Indebtedness or
               Entitled Persons.

         The Trustee shall not be deemed to owe any fiduciary duty to the
holders of Senior Indebtedness or Entitled Persons in respect of Other Financial
Obligations and shall not be liable to any such holders or creditors if it shall
in good faith mistakenly pay over or distribute to Holders of Securities or to
the Company or to any other Person cash, property or securities to which any
holders of Senior Indebtedness or Entitled Persons in respect of Other Financial
Obligations shall be entitled by virtue of this Article or otherwise.

SECTION 14.13. Rights of Trustee as Holder of Senior Indebtedness or Entitled
               Person; Preservation of Trustee's Rights.

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

         Nothing in this Article shall apply to claims of, or payments to, the
Trustee under or pursuant to Section 6.07.

SECTION 14.14. 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
<PAGE>   76

                                                                             68

Paying Agent within its meaning as fully for all intents and purposes as if such
Paying Agent were named in this Article in addition to or in place of the
Trustee; provided, however, that Section 14.13 shall not apply to the Company or
any Affiliate of the Company if it or such Affiliate acts as Paying Agent.

SECTION 14.15. Securities to Rank Pari Passu with Existing Subordinated
               Indebtedness; Payment of Proceeds in Certain Cases.

              (a) Subject to the provisions of this Section and to any
         provisions established or determined with respect to Securities of any
         series pursuant to Section 3.01, the Securities shall rank pari passu
         in right of payment with all other Securities and the Existing
         Subordinated Indebtedness.

              (b) Upon the occurrence of any of the events specified in clauses
         (a), (b) and (c) of the first paragraph of Section 14.02, the
         provisions of that Section to determine the amount of cash, property or
         securities which may be payable or deliverable as between the holders
         of Senior Indebtedness, on the one hand, and the Holders of Securities,
         on the other hand.

              (c) If, after giving effect to the provisions of Section 14.02 and
         Section 14.06, any amount of cash, property or securities shall be
         available for payment or distribution in respect of the Securities
         ("Excess Proceeds"), and any Entitled Persons in respect of Other
         Financial Obligations shall not have received payment in full of all
         amounts due or to become due on or in respect of such Other Financial
         Obligations (and provision shall not have been made for such payment in
         money or money's worth), then such Excess Proceeds shall first be
         applied (ratably with any amount of cash, property or securities
         available for payment or distribution in respect of any other
         indebtedness of the Company that by its express terms provides for the
         payment over of amounts corresponding to Excess Proceeds to Entitled
         Persons in respect of Other Financial Obligations) to pay or provide
         for the payment of the Other Financial Obligations remaining unpaid, to
         the extent necessary to pay all Other Financial Obligations in full,
         after giving effect to any concurrent payment or distribution to or for
         Entitled Persons in respect of Other Financial Obligations. Any Excess
         Proceeds remaining after the payment (or provision for payment) in full
         of all Other Financial Obligations shall be available for payment or
         distribution in respect of the Securities.

              (d) In the event that, notwithstanding the foregoing provisions of
         subsection (c) of this Section, after the occurrence of any of the
         events specified in clauses (a), (b) and (c) of the first paragraph of
         Section 14.02, the Trustee or Holder of any Security shall have
         received any payment or distribution of assets of the Company of any
         kind or character, whether in cash, property or securities, before
         Senior Indebtedness and all Other Financial Obligations are paid in
         full or payment thereof duly provided for, and if such fact shall, at
         or prior to the time of such payment or distribution, have been made
         known to the Trustee or, as the case may be, such Holder, then and in
         such event, subject to any obligation that the Trustee or such Holder
         may have pursuant to Section 14.02, such payment or distribution shall
         be paid over or delivered forthwith to the trustee in bankruptcy,
         receiver, liquidating trustee, custodian, assignee, agent or other
         Person making payment or distribution of assets of the Company for
         payment in accordance with subsection (c).
<PAGE>   77

                                                                             69

              (e) Subject to the payment in full of all Other Financial
         Obligations, the Holders of the Securities shall be subrogated (equally
         and ratably with the holders of all indebtedness of the Company that by
         its express terms provides for the payment over of amounts
         corresponding to Excess Proceeds to Entitled Persons in respect of
         Other Financial Obligations and is entitled to like rights of
         subrogation) to the extent of the payments or distributions made to
         Entitled Persons in respect of Other Financial Obligations pursuant to
         subsection (c) or (d) of this Section to the rights of the Entitled
         Persons in respect of Other Financial Obligations to receive payments
         and distributions of cash, property and securities applicable to the
         Other Financial Obligations until the principal of (and premium, if
         any) and interest on the Securities shall be paid in full. For purposes
         of such subrogation, no payments or distributions to Entitled Persons
         in respect of Other Financial Obligations of any cash, property or
         securities to which Holders of the Securities or the Trustee would be
         entitled except for the provisions of this Section, and no payments
         over pursuant to the provisions of this Section to Entitled Persons in
         respect of Other Financial Obligations by Holders of Securities or the
         Trustee, shall, as among the Company, its creditors other than Entitled
         Persons in respect of Other Financial Obligations and the Holders of
         Securities be deemed to be a payment or distribution by the Company to
         or on account of the Other Financial Obligations.

              (f) The provisions of subsections (c), (d) and (e) of this Section
         are and are intended solely for the purpose of defining the relative
         rights of the Holders of the Securities, on the one hand, and the
         Entitled Persons in respect of Other Financial Obligations, on the
         other hand, after giving effect to the rights of the holders of Senior
         Indebtedness, as provided in this Article. Nothing contained in
         subsections (c), (d) and (e) of this Section is intended to or shall
         affect the relative rights against the Company of the Holders of the
         Securities and creditors of the Company other than Entitled Persons in
         respect of Other Financial Obligations.

SECTION 14.16. Certain Conversions Deemed Payment.

         For purposes of this Article only, the issuance and delivery of junior
securities upon conversion of Securities in accordance with Article Fifteen
shall not be deemed to constitute a payment or distribution on account of the
purchase or other acquisition of Securities, and (2) the payment, issuance or
delivery of cash, property or securities (other than junior securities) upon
conversion of a security shall be deemed to constitute payment on account of the
principal of such Securities. For purposes of this Section, the term "junior
securities" means (a) shares of any stock of any class of the Company and (b)
securities of the Company which are subordinated in right of payment to all
Senior Indebtedness and Other Financial Obligations which may be outstanding at
the time of issuance or delivery of such securities to substantially the same
extent as, or to a greater extent than, the Securities are so subordinated as
provided in this Article. Nothing contained in this Article or elsewhere in this
Indenture or in the Securities is intended to or shall impair, as among the
Company, its creditors other than holders of Senior Indebtedness and the Holders
of the Securities, the right, which is absolute and unconditional, of the Holder
of any convertible Security to convert such Security in accordance with Article
Fifteen.
<PAGE>   78

                                                                             70

                                ARTICLE FIFTEEN

                            CONVERSION OF SECURITIES

SECTION 15.01. Applicability of Article.

         The Company may elect, at its option at any time, to have Section 15.02
applied to any Securities or any series of Securities, as the case may be,
designated pursuant to Section 3.01 as being convertible into Common Stock of
the Company pursuant to such Section 15.02, in accordance with any applicable
requirements provided pursuant to Section 3.01 and upon compliance with the
conditions set forth below in this Article. Any such election shall be evidenced
by a Board Resolution or in another manner specified as contemplated by Section
3.01 for such Securities.

SECTION 15.02. Conversion Privilege and Conversion Price.

         Subject to and upon compliance with the provisions of this Article, at
the option of the Holder thereof, any Security or any portion of the principal
amount thereof which is an integral multiple of the authorized denomination
thereof may be converted at the principal amount thereof, or of such portion
thereof, into fully paid and nonassessable shares (calculated as to each
conversion to the nearest 1/100 of a share) of Common Stock of the Company, at
the conversion price for Securities of such series, determined as hereinafter
provided, in effect at the time of conversion. Such conversion right shall
commence at the opening of business on the Initial Conversion Date and expire at
the close of business on the Final Conversion Date. In case a Security or
portion thereof is called for redemption, such conversion right in respect of
the Security or portion so called shall expire at the close of business on the
Redemption Date, unless the Company defaults in making the payment due upon
redemption.

         The price at which shares of Common Stock shall be delivered upon
conversion of Securities of a series (herein called the "conversion price" for
Securities of such series) shall be initially the Initial Conversion Price for
Securities of such series per share of Common Stock. The conversion price shall
be adjusted in certain instances as provided in paragraphs (1), (2), (3), (4)
and (7) of Section 15.05.

SECTION 15.03. Exercise of Conversion Privilege.

         In order to exercise the conversion privilege, the Holder of any
Security to be converted shall surrender such Security, duly endorsed or
assigned to the Company or in blank, at any office or agency of the Company
maintained for that purpose pursuant to Section 10.02, accompanied by written
notice to the Company at such office or agency that the Holder elects to convert
such Security or, if less than the entire principal amount thereof is to be
converted, the portion thereof to be converted. Securities surrendered for
conversion during the period from the close of business on any Regular Record
Date next preceding any Interest Payment Date to the opening of business on such
Interest Payment Date shall (except in the case of Securities or portions
thereof which have been called for redemption on a Redemption Date within such
period) be accompanied by payment in legal tender or other funds acceptable to
the Company of an amount equal to the interest payable on such Interest Payment
Date on the principal amount of Securities being surrendered for conversion.
Except as provided in the preceding sentence and subject to the last paragraph
of Section 3.07, no payment or adjustment shall be made upon any
<PAGE>   79

                                                                             71

conversion on account of any interest accrued on the Securities surrendered for
conversion or on account of any dividends on the Common Stock issued upon
conversion.

         Securities shall be deemed to have been converted immediately prior to
the close of business on the day of surrender of such Securities for conversion
in accordance with the foregoing provisions, and at such time the rights of the
Holders of such Securities as Holders shall cease, and the Person or Persons
entitled to receive the Common Stock issuable upon conversion shall be treated
for all purposes as the record holder or holders of such Common Stock at such
time. As promptly as practicable on or after the conversion date, the Company
shall issue and shall deliver at such office or agency a certificate or
certificates for the number of full shares of Common Stock issuable upon
conversion, together with payment in lieu of any fraction of a share, as
provided in Section 15.04.

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

SECTION 15.04. Fractions of Shares.

         No fractional shares of Common Stock shall be issued upon conversion of
Securities. If more than one Security of a series shall be surrendered for
conversion at one time by the same Holder, the number of full shares which shall
be issuable upon conversion thereof shall be computed on the basis of the
aggregate principal amount of the Securities of such series (or specified
portions thereof) so surrendered. Instead of any fractional share of Common
Stock which would otherwise be issuable upon conversion of any Security or
Securities (or specified portion thereof), the Company shall pay a cash
adjustment in respect of such fraction in an amount equal (computed to the
nearest cent) to the same fraction of the market price per share of Common Stock
(as determined by the Board of Directors or in any manner prescribed by the
Board of Directors) at the close of business on the day of conversion.

SECTION 15.05. Adjustment of Conversion Price.

              (1) In case at any time after the date of establishment of the
         Initial Conversion Price with respect to Securities of a series the
         Company shall pay or make a dividend or other distribution in shares of
         Common Stock on any class of capital stock of the Company, the
         conversion price in effect at the opening of business on the day
         following the date fixed for the determination of stockholders entitled
         to receive such dividend or other distribution shall be reduced by
         multiplying such conversion price by a fraction of which the numerator
         shall be the number of shares of Common Stock outstanding at the close
         of business on the date fixed for such determination and the
         denominator shall be the sum of such number of shares and the total
         number of shares constituting such dividend or other distribution, such
         reduction to become effective immediately after the opening of business
         on the day following the date fixed for such determination. For the
         purposes of this paragraph, the number of shares of Common Stock at any
         time outstanding shall not include shares held in the treasury of the
         Company. The Company will not pay any dividend or make any distribution
         on shares of Common Stock held in the treasury of the Company.
<PAGE>   80

                                                                             72

              (2) In case at any time after the date of establishment of the
         Initial Conversion Price with respect to Securities of a series the
         Company shall issue rights or warrants to all holders of its Common
         Stock entitling them to subscribe for or purchase shares of Common
         Stock at a price per share less than the current market price per share
         (determined as provided in paragraph (6) of this Section) of the Common
         Stock on the date fixed for the determination of stockholders entitled
         to receive such rights or warrants, the conversion price in effect at
         the opening of business on the day following the date fixed for such
         determination shall be reduced by multiplying such conversion price by
         a fraction of which the numerator shall be the number of shares of
         Common Stock outstanding at the close of business on the date fixed for
         such determination plus the number of shares of Common Stock which the
         aggregate of the offering price of the total number of shares of Common
         Stock so offered for subscription or purchase would purchase at such
         current market price and the denominator shall be the number of shares
         of Common Stock outstanding at the close of business on the dated fixed
         for such determination plus the number of shares of Common Stock so
         offered for subscription or purchase, such reduction to become
         effective immediately after the opening of business on the day
         following the date fixed for such determination. For the purposes of
         this paragraph (2), the number of shares of Common Stock at any time
         outstanding shall not include shares held in the treasury of the
         Company. The Company will not issue any rights or warrants in respect
         of shares of Common Stock held in the treasury of the Company.

              (3) In case at any time after the date of establishment of the
         Initial Conversion Price with respect to Securities of a series
         outstanding shares of Common Stock shall be subdivided into a greater
         number of shares of Common Stock, the conversion price in effect at the
         opening of business on the day following the day upon which such
         subdivision becomes effective shall be proportionately reduced, and,
         conversely, in case outstanding shares of Common Stock shall each be
         combined into a smaller number of shares of Common Stock, the
         conversion price in effect at the opening of business on the day
         following the day upon which such combination becomes effective shall
         be proportionately increased, such reduction or increase, as the case
         may be, to become effective immediately after the opening of business
         on the day following the day upon which such subdivision or combination
         becomes effective.

              (4) In case at any time after the date of establishment of the
         Initial Conversion Price with respect to Securities of a series the
         Company shall, by dividend or otherwise, distribute to all holders of
         its Common Stock evidences of its indebtedness or assets (including
         securities, but excluding any rights or warrants referred to in
         paragraph (2) of this Section, any dividend or distribution paid in
         cash out of the retained earnings of the Company and any dividend or
         distribution referred to in paragraph (1) of this Section), the
         conversion price shall be adjusted so that the same shall equal the
         price determined by multiplying the conversion price in effect
         immediately prior to the close of business on the date fixed for the
         determination of stockholders entitled to receive such distribution by
         a fraction of which the numerator shall be the current market price per
         share (determined as provided in paragraph (6) of this Section) of the
         Common Stock on the date fixed for such determination less the then
         fair market value (as determined by the Board of Directors, whose
         determination shall be conclusive and described in a Board Resolution
         filed with the Trustee) of the portion of assets or evidences of
         indebtedness so

<PAGE>   81

                                                                             73

         distributed applicable to one share of Common Stock and the denominator
         shall be such current market price per share of the Common Stock, such
         adjustment to become effective immediately prior to the opening of
         business on the day following the date fixed for the determination of
         stockholders entitled to receive such distribution.

              (5) The reclassification of Common Stock into securities other
         than Common Stock (other than any reclassification upon a consolidation
         or merger to which Section 15.02 applies) shall be deemed to involve
         (a) a distribution of such securities other than Common Stock to all
         holders of Common Stock (and the effective date of such
         reclassification shall be deemed to be "the date fixed for the
         determination of stockholders entitled to receive such distribution"
         and "the date fixed for such determination" within the meaning of
         paragraph (4) of this Section), and (b) a subdivision or combination,
         as the case may be, of the number of shares of Common Stock outstanding
         immediately prior to such reclassification into the number of shares of
         Common Stock outstanding immediately thereafter (and the effective date
         of such reclassification shall be deemed to be "the day upon which such
         subdivision becomes effective" or "the day upon which such combination
         becomes effective", as the case may be, and "the day upon which such
         subdivision or combination becomes effective" within the meaning of
         paragraph (3) of this Section).

              (6) For the purpose of any computation under paragraphs (2) and
         (4) of this Section, the current market price per share of Common Stock
         on any date shall be deemed to be the average of the daily closing
         prices for the 30 consecutive Business Days selected by the Company
         commencing not less than 30 nor more than 45 Business Days before the
         day in question. The closing price for each day shall be the last
         reported sales price regular way or, in case no such reported sale
         takes place on such day, the average of the reported closing bid and
         asked prices regular way, in either case, on the principal national
         securities exchange on which the Common Stock are listed or admitted to
         trading or, if not listed or admitted to trading on any national
         securities exchange, on the National Association of Securities Dealers
         Automated Quotations National Market System or, if the Common Stock is
         not listed or admitted to trading on any national securities exchange
         or quoted on such National Market System, the average of the closing
         bid and asked prices in the over-the-counter market as furnished by any
         New York Stock Exchange member firm selected from time to time by the
         Company for that purpose.

              (7) The Company may make such reductions in the conversion price,
         in addition to those required by paragraphs (1), (2), (3) and (4) of
         this Section, as it considers to be advisable in order that any event
         treated for Federal income tax purposes as a dividend of stock or stock
         rights shall not be taxable to the recipients.

SECTION 15.06. Notice of Adjustments of Conversion Price.

         Whenever the conversion price is adjusted as herein provided:

              (a) the Company shall compute the adjusted conversion price in
         accordance with Section 15.05 and shall prepare a certificate signed by
         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 at
         each
<PAGE>   82

                                                                             74

         office or agency maintained for the purpose of conversion of Securities
         pursuant to Section 10.02; and

              (b) a notice stating that the conversion price has been adjusted
         and setting forth the adjusted conversion price shall forthwith be
         required, and as soon as practicable after it is required, such notice
         shall be mailed by the Company to all Holders at their respective last
         addresses as they shall appear in the Security Register.

SECTION 15.07. Notice of Certain Corporate Action.

         In case at any time after 20 Business Days preceding the Initial
Conversion Date:

              (a) the Company shall declare a dividend (or any other
         distribution) on its Common Stock payable otherwise than in cash out of
         its retained earnings; or

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

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

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

then the Company shall cause to be filed at each office or agency maintained for
the purpose of conversion of Securities pursuant to Section 10.02, and shall
cause to be mailed to all Holders at their respective last addresses as they
shall appear in the Security Register, at least 20 days (or 10 days in any case
specified in Clause (a) or (b) above) prior to the applicable record or
effective date hereinafter specified, a notice stating (x) the date on which a
record 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, 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,
dissolution, liquidation or winding up.

SECTION 15.08. Company to Reserve Common Stock.

         The Company shall at all times reserve and keep available, free from
pre-emptive rights, out of its authorized but unissued Common Stock, for the
purpose of effecting the conversion of Securities, the full number of shares of
Common Stock then issuable upon the conversion of all outstanding Securities.
<PAGE>   83

                                                                             75

SECTION 15.09. Taxes on Conversions.

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

SECTION 15.10. Covenant as to Common Stock.

         The Company covenants that all shares of Common Stock which may be
issued upon conversion of Securities will upon issue be fully paid and
nonassessable and, except as provided in Section 15.09, the Company will pay all
taxes, liens and charges with respect to the issue thereof.

SECTION 15.11. Cancellation of Converted Securities.

         All Securities delivered for conversion shall be delivered to the
Trustee to be cancelled by or at the direction of the Trustee, which shall
dispose of the same as provided in Section 3.09.

SECTION 15.12. Provisions in Case of Consolidation, Merger or Sale of Assets.

         In case of any consolidation of the Company with, or merger of the
Company into, any other Person, any merger of another Person into the Company
(other than a merger which does not result in any reclassification, conversion,
exchange or cancellation of outstanding shares of Common Stock of the Company)
or any sale or transfer of all or substantially all of the assets of the
Company, the Person formed by such consolidation or resulting from such merger
or which acquires such assets, as the case may be, shall execute and deliver to
the Trustee a supplemental indenture providing that the Holder of each Security
then outstanding shall have the right thereafter, during the period such
Security shall be convertible as specified in Section 15.02, to convert such
Security only into the kind and amount of securities, cash and other property
receivable upon such consolidation, merger, sale or transfer by a holder of the
number of shares of Common Stock of the Company into which such Security might
have been converted immediately prior to such consolidation, merger, sale or
transfer, assuming such holder of Common Stock of the Company (i) is not a
Person with which the Company consolidated or into which the Company merged or
which merged into the Company or to which such sale or transfer was made, as the
case may be ("constituent Person"), or an Affiliate of a constituent Person and
(ii) failed to exercise his rights of election, if any, as to the kind or amount
of securities, cash and other property receivable upon such consolidation,
merger, sale or transfer (provided that if the kind or amount of securities,
cash and other property receivable upon such consolidation, merger, sale or
transfer is not the same for each share of Common Stock of the Company held
immediately prior to such consolidation, merger, sale or transfer by others than
a constituent Person or an Affiliate thereof and in respect of which such rights
of election shall not have been exercised ("non-electing share"), then for the
purpose of this Section the kind and amount of securities, cash and other
property receivable upon such consolidation, merger, sale or transfer by each
non-electing share shall be deemed to be the kind and amount so receivable per
share by a plurality of the non-electing shares), and assuming, if such
consolidation, merger, sale or
<PAGE>   84

                                                                             76

transfer is prior to the Initial Conversion Date, that the Securities were
convertible at the time of such consolidation, merger, sale or transfer at the
initial conversion price specified in Section 15.02 as adjusted from the date of
establishment of the Initial Conversion Price with respect to Securities of a
series to such time pursuant to paragraphs (1), (2), (3), (4) and (7) of Section
15.05. Such supplemental indenture shall provide for adjustments which, for
events subsequent to the effective date of such supplemental indenture, shall be
as nearly equivalent as may be practicable to the adjustments provided for in
this Article. The above provisions of this Section shall similarly apply to
successive consolidations, mergers, sales or transfers.

SECTION 15.13. Responsibility of Trustee.

         The Trustee shall not at any time be under any duty or responsibility
to any Holder of a Security to make or cause to be made any adjustment of the
conversion price, or to determine whether any facts exist which may require any
such adjustment, or with respect to the nature or extent of any such adjustment
when made, or with respect to any method employed, or herein or in any
supplemental indenture provided to be employed, in making the same. The Trustee
shall not be accountable with respect to the validity or value (or the kind or
amount) of any shares of Common Stock or of any securities or property which may
at any time be issued or delivered upon conversion of any Security; and the
Trustee makes no representation with respect thereto. The Trustee shall not be
responsible for any failure of the Company to issue, transfer or deliver any
shares of Common Stock or stock certificates or other securities or property
upon surrender of any Security for the purpose of conversion or to comply with
any of the covenants of the Company contained in this Article Fifteen.



<PAGE>   85
                                                                             77


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

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

                                          ASSOCIATED BANC-CORP


                                          By.____________________________





                                          THE BANK OF NEW YORK, as Trustee


                                          By____________________________