<PAGE>   1
                                   EXHIBIT 4.1

                             NOVELLUS SYSTEMS, INC.



                         Liquid Yield Option (TM) Notes
                                    due 2031
                           (Zero Coupon-Subordinated)
           ----------------------------------------------------------

                                    INDENTURE

                            Dated as of July 26, 2001
           ----------------------------------------------------------

                        LASALLE BANK NATIONAL ASSOCIATION

                                     TRUSTEE

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

                   (TM)Trademark of Merrill Lynch & Co., Inc.



<PAGE>   2





                             CROSS REFERENCE TABLE*

<TABLE>
<S>                                                                       <C>
IA Section......................................................          Indenture Section
310(a)(1).......................................................                7.10
     (a)(2).....................................................                7.10
     (a)(3).....................................................                 N/A
     (a)(4).....................................................                 N/A
     (b)........................................................             7.08; 7.10
     (c)........................................................                 N/A
311(a)..........................................................                7.11
     (b)........................................................                7.11
     (c)........................................................                 N/A
312(a)..........................................................                2.05
     (b)........................................................                12.03
     (c)........................................................                12.03
313(a)..........................................................                7.06
     (b)(1).....................................................                 N/A
     (b)(2).....................................................                7.06
     (c)........................................................                14.02
     (d)........................................................                7.06
314(a)..........................................................          4.02; 4.03; 12.02
     (b)........................................................                 N/A
     (c)(1).....................................................                14.04
     (c)(2).....................................................                14.04
     (c)(3).....................................................                 N/A
     (d)........................................................                 N/A
     (e)........................................................                12.05
     (f)........................................................                 N/A
315(a)..........................................................                7.01
     (b)........................................................             7.05; 12.02
     (c)........................................................                7.01
     (d)........................................................                7.01
     (e)........................................................                6.11
316(a) (last sentence)..........................................                2.08
     (a)(1)(A)..................................................                6.05
     (a)(1)(B)..................................................                6.04
     (a)(2).....................................................                 N/A
     (b)........................................................                6.07
317(a)(1).......................................................                6.08
     (a)(2).....................................................                6.09
     (b)........................................................                2.04
318(a)..........................................................                12.01
</TABLE>


--------

*    Note: This Cross Reference Table shall not, for any purpose, be deemed to
     be part of the Indenture.

<PAGE>   3



<TABLE>
<CAPTION>
                                                 Table of Contents
                                                                                                          Page
                                                                                                          ----

                                                     ARTICLE 1


                                    DEFINITIONS AND INCORPORATION BY REFERENCE

<S>       <C>                                                                                             <C>
  SECTION 1.01 Definitions.................................................................................1
  SECTION 1.02 Other Definitions...........................................................................6
  SECTION 1.03 Incorporation by Reference of Trust Indenture Act...........................................7
  SECTION 1.04 Rules of Construction.......................................................................7
  SECTION 1.05 Acts of Holders.............................................................................7

                                                     ARTICLE 2

                                                  THE SECURITIES

  SECTION 2.01 Form and Dating.............................................................................9
  SECTION 2.02 Execution and Authentication...............................................................10
  SECTION 2.03 Registrar, Paying Agent, Conversion Agent and Bid Solicitation Agent.......................11
  SECTION 2.04 Paying Agent to Hold Money and Securities in Trust.........................................11
  SECTION 2.05 Securityholder Lists.......................................................................12
  SECTION 2.06 Transfer and Exchange......................................................................12
  SECTION 2.07 Replacement Securities.....................................................................13
  SECTION 2.08 Outstanding Securities; Determinations of Holders' Action..................................14
  SECTION 2.09 Temporary Securities.......................................................................15
  SECTION 2.10 Cancellation...............................................................................15
  SECTION 2.11 Persons Deemed Owners......................................................................15
  SECTION 2.12 Global Securities..........................................................................16
  SECTION 2.13 CUSIP Numbers..............................................................................18

                                                     ARTICLE 3

                                             REDEMPTION AND PURCHASES

  SECTION 3.01 Right to Redeem; Notices to Trustee........................................................18
  SECTION 3.02 Selection of Securities to Be Redeemed.....................................................18
  SECTION 3.03 Notice of Redemption.......................................................................19
  SECTION 3.04 Effect of Notice of Redemption.............................................................20
  SECTION 3.05 Deposit of Redemption Price................................................................20
  SECTION 3.06 Securities Redeemed in Part................................................................20
  SECTION 3.07 Conversion Arrangement on Call for Redemption..............................................20
  SECTION 3.08 Purchase of Securities at Option of the Holder.............................................21
  SECTION 3.09 Purchase of Securities at Option of the Holder upon a Change in Control....................27
  SECTION 3.10 Effect of Purchase Notice or Change in Control Purchase Notice.............................31
  SECTION 3.11 Deposit of Purchase Price or Change in Control Purchase Price..............................32
  SECTION 3.12 Securities Purchased in Part...............................................................33
  SECTION 3.13 Covenant to Comply With Securities Laws Upon Purchase of Securities........................33
  SECTION 3.14 Repayment to the Company...................................................................33
</TABLE>

                                       i

<PAGE>   4


                                   ARTICLE 4

                                   COVENANTS

<TABLE>
<S>       <C>                                                                                             <C>
  SECTION 4.01 Payment of Securities......................................................................33
  SECTION 4.02 SEC and Other Reports......................................................................34
  SECTION 4.03 Compliance Certificate.....................................................................34
  SECTION 4.04 Further Instruments and Acts...............................................................34
  SECTION 4.05 Maintenance of Office or Agency............................................................35
  SECTION 4.06 Delivery of Certain Information............................................................35
  SECTION 4.07 Calculation of Tax Original Issue Discount.................................................35

                                                     ARTICLE 5

                                               SUCCESSOR CORPORATION

  SECTION 5.01 When Company May Merge or Transfer Assets..................................................35

                                                     ARTICLE 6


                                               DEFAULTS AND REMEDIES

  SECTION 6.01 Events of Default..........................................................................36
  SECTION 6.02 Acceleration...............................................................................38
  SECTION 6.03 Other Remedies.............................................................................39
  SECTION 6.04 Waiver of Past Defaults....................................................................39
  SECTION 6.05 Control by Majority........................................................................39
  SECTION 6.06 Limitation on Suits........................................................................39
  SECTION 6.07 Rights of Holders to Receive Payment.......................................................40
  SECTION 6.08 Collection Suit by Trustee.................................................................40
  SECTION 6.09 Trustee May File Proofs of Claim...........................................................40
  SECTION 6.10 Priorities.................................................................................41
  SECTION 6.11 Undertaking for Costs......................................................................41
  SECTION 6.12 Waiver of Stay, Extension or Usury Laws....................................................42

                                                     ARTICLE 7


                                                      TRUSTEE

  SECTION 7.01 Duties of Trustee..........................................................................42
  SECTION 7.02 Rights of Trustee..........................................................................43
  SECTION 7.03 Individual Rights of Trustee...............................................................44
  SECTION 7.04 Trustee's Disclaimer.......................................................................45
  SECTION 7.05 Notice of Defaults.........................................................................45
  SECTION 7.06 Reports by Trustee to Holders..............................................................45
  SECTION 7.07 Compensation and Indemnity.................................................................45
  SECTION 7.08 Replacement of Trustee.....................................................................46
  SECTION 7.09 Successor Trustee by Merger................................................................47
  SECTION 7.10 Eligibility; Disqualification..............................................................47
  SECTION 7.11 Preferential Collection of Claims Against Company..........................................47
</TABLE>

                                       ii

<PAGE>   5




                                   ARTICLE 8


                             DISCHARGE OF INDENTURE

<TABLE>
<S>       <C>                                                                                            <C>
  SECTION 8.01 Discharge of Liability on Securities.......................................................47
  SECTION 8.02 Repayment to the Company...................................................................48

                                                     ARTICLE 9


                                                    AMENDMENTS

  SECTION 9.01 Without Consent of Holders.................................................................48
  SECTION 9.02 With Consent of Holders....................................................................49
  SECTION 9.03 Compliance with Trust Indenture Act........................................................50
  SECTION 9.04 Revocation and Effect of Consents, Waivers and Actions.....................................50
  SECTION 9.05 Notation on or Exchange of Securities......................................................50
  SECTION 9.06 Trustee to Sign Supplemental Indentures....................................................50
  SECTION 9.07 Effect of Supplemental Indentures..........................................................50

                                                    ARTICLE 10


                                                   SUBORDINATION

  SECTION 10.01 Securities Subordinate to Senior Indebtedness..............................................50
  SECTION 10.02 Payment Over of Proceeds Upon Dissolution, Etc.............................................51
  SECTION 10.03 Acceleration of Securities.................................................................52
  SECTION 10.04 Default on Senior Indebtedness.............................................................52
  SECTION 10.05 Payment Permitted If No Default............................................................53
  SECTION 10.06 Subrogation to Rights of Holders of Senior Indebtedness....................................53
  SECTION 10.07 Provisions Solely to Define Relative Rights................................................53
  SECTION 10.08 Trustee to Effectuate Subordination........................................................54
  SECTION 10.09 No Waiver of Subordination Provisions......................................................54
  SECTION 10.10 Notice to Trustee..........................................................................54
  SECTION 10.11 Reliance on Judicial Order or Certificate of Liquidating Agent.............................55
  SECTION 10.12 Trustee Not Fiduciary for Holders of Senior Indebtedness...................................55
  SECTION 10.13 Rights of Trustee as Holder of Senior Indebtedness; Preservation of Trustee's Rights.......56
  SECTION 10.14 Article 10 Applicable to Paying Agents.....................................................56
  SECTION 10.15 Enforcement of Rights Under the Pledge Agreement...........................................56

                                                    ARTICLE 11


                                                    CONVERSION

  SECTION 11.01 Conversion Privilege.......................................................................56
  SECTION 11.02 Conversion Procedure.......................................................................57
  SECTION 11.03 Fractional Shares..........................................................................58
  SECTION 11.04 Taxes on Conversion........................................................................58
  SECTION 11.05 Company to Provide Stock...................................................................58
  SECTION 11.06 Adjustment for Change In Capital Stock.....................................................59
  SECTION 11.07 Adjustment for Rights Issue................................................................60
  SECTION 11.08 Adjustment for Other Distributions.........................................................61
</TABLE>

                                      iii

<PAGE>   6


<TABLE>
<S>       <C>                                                                                             <C>
  SECTION 11.09 When Adjustment May Be Deferred............................................................63
  SECTION 11.10 When No Adjustment Required................................................................63
  SECTION 11.11 Notice of Adjustment.......................................................................63
  SECTION 11.12 Voluntary Increase.........................................................................64
  SECTION 11.13 Notice of Certain Transactions.............................................................64
  SECTION 11.14 Reorganization of Company; Special Distributions...........................................64
  SECTION 11.15 Company Determination Final................................................................65
  SECTION 11.16 Trustee's Adjustment Disclaimer............................................................65
  SECTION 11.17 Simultaneous Adjustments...................................................................65
  SECTION 11.18 Successive Adjustments.....................................................................65
  SECTION 11.19 Rights Issued in Respect of Common Stock Issued Upon Conversion............................66

                                                    ARTICLE 12


                                                PAYMENT OF INTEREST

  SECTION 12.01 Interest Payments..........................................................................66
  SECTION 12.02 Defaulted Interest.........................................................................66
  SECTION 12.03 Interest Rights Preserved. ................................................................67

                                                    ARTICLE 13


                                                   MISCELLANEOUS

  SECTION 13.01 Trust Indenture Act Controls...............................................................67
  SECTION 13.02 Notices....................................................................................67
  SECTION 13.03 Communication by Holders with Other Holders................................................68
  SECTION 13.04 Certificate and Opinion as to Conditions Precedent.........................................69
  SECTION 13.05 Statements Required in Certificate or Opinion..............................................69
  SECTION 13.06 Severability Clause........................................................................69
  SECTION 13.07 Rules by Trustee, Paying Agent, Conversion Agent and Registrar.............................69
  SECTION 13.08 Calculations...............................................................................69
  SECTION 13.09 Legal Holidays.............................................................................70
  SECTION 13.10 GOVERNING LAW..............................................................................70
  SECTION 13.11 No Recourse Against Others.................................................................70
  SECTION 13.12 Successors.................................................................................70
  SECTION 13.13 Multiple Originals.........................................................................70
  SECTION 13.14 Tax Matters................................................................................70
</TABLE>

                                       iv

<PAGE>   7



        INDENTURE dated as of July 26, 2001, among NOVELLUS SYSTEMS, INC., a
California corporation ("Company") and LASALLE BANK NATIONAL ASSOCIATION, a
National Banking Association ("Trustee").

        Each party agrees as follows for the benefit of the other party and for
the equal and ratable benefit of the Holders of the Company's Liquid Yield
Option(TM) Notes due 2031 (Zero Coupon -- Subordinated) ("Securities"):

              ARTICLE 1 DEFINITIONS AND INCORPORATION BY REFERENCE

        SECTION 1.01 Definitions.

        "144A Global Security" means a permanent Global Security in the form of
the Security attached hereto as Exhibit A-1, and that is deposited with and
registered in the name of the Depositary or its nominee, representing Securities
sold in reliance on Rule 144A under the Securities Act.

        "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 or cause the direction of the management and policies of such person,
directly or indirectly, whether through the ownership of voting securities, by
contract or otherwise; and the terms "controlling" and "controlled" have
meanings correlative to the foregoing.

        "Applicable Procedures" means, with respect to any transfer or
transaction involving a Global Security or beneficial interest therein, the
rules and procedures of the Depositary for such Security as disclosed in writing
to the Company, in each case to the extent applicable to such transaction and as
in effect from time to time.

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

        "Business Day" means each day of the year other than a Saturday or a
Sunday or other day on which banking institutions in The City of New York and
Chicago, Illinois are required or authorized to close.

        "Capital Stock" for any corporation means any and all shares, interests,
rights to purchase, warrants, options, participations or other equivalents of or
interests in (however designated) stock issued by that corporation.

        "Common Stock" shall mean the shares of common stock of the Company, no
par value per share, as it exists on the date of this Indenture or any other
shares of Capital Stock of the Company into which the Common Stock shall be
reclassified or changed.

        "Company" means the party named as the "Company" in the first paragraph
of this Indenture until a successor replaces it pursuant to the applicable
provisions of this Indenture and, thereafter, shall mean such successor. The
foregoing sentence shall likewise apply to any such subsequent successor or
successors.

        "Company Request" or "Company Order" means a written request or order
signed in the name of the Company by any two Officers.

        "Conversion Price" shall have the meaning set forth in paragraph 10 of
the reverse side of the form of Security, set forth in Exhibit A-1 of this
Indenture.

        "Corporate Trust Office" means the principal office of the Trustee at
which at any time its corporate trust business shall be administered, which
office at the date hereof is located at 135 South LaSalle Street, Suite 1960,
Chicago, Illinois 60603, Attention: Corporate Trust Services Division, or such
other address as the Trustee may designate from time to time by notice to the
Holders and the Company, or the principal corporate trust office of any
successor Trustee (or such other address as a successor Trustee may designate
from time to time by notice in writing to the Holders and the Company).



<PAGE>   8


        "Default" means any event or condition which is, or after notice or
passage of time or both would be, an Event of Default.

        "Global Securities" means Securities that are substantially in the form
of the Securities attached hereto as Exhibit A-1, and to the extent that such
Securities are required to bear the Legend required by Section 2.06, such
Securities will be in the form of a 144A Global Security.

        "Holder" or "Securityholder" means a person in whose name a Security is
registered on the Registrar's books.

        "Indenture" means this Indenture, as amended or supplemented from time
to time in accordance with the terms hereof, including the provisions of the TIA
that are deemed to be a part hereof.

        "Issue Date" of any Security means the date on which such Security was
originally issued or deemed issued as set forth on the face of the Security.

        "Issue Price" of any Security means, in connection with the original
issuance of such Security, the initial issue price at which such Security is
sold as set forth on the face of the Security.

        "Liquidated Damages" has the meaning set forth in the Registration
Rights Agreement.

        "Officer" means, with respect to any Person, the Chairman of the Board,
the President or any Vice President, the Treasurer, an Assistant Treasurer, the
Controller, an Assistant Controller, the Secretary or an Assistant Secretary of
such Person.

        "Officers' Certificate" means a written certificate containing, among
other things, the information specified in Sections 13.04 and 13.05, signed in
the name of the Company by any two Officers, and delivered to the Trustee. An
Officers' Certificate given pursuant to Section 4.03 shall be signed by the
principal financial or accounting Officer of the Company but need not contain
the information specified in Sections 13.04 and 13.05.

        "Opinion of Counsel" means a written opinion conforming to the
requirements specified in Sections 13.04 and 13.05, from legal counsel who is
reasonably acceptable to the Trustee. The counsel may be an employee of, or
counsel to, the Company or the Trustee.

        "Participation Agreements" mean participation agreements of the company
in effect on the date hereof providing for obligations and liabilities,
contingent or otherwise, in respect of leases of the Company where the Company
is contractually obligated to purchase or cause a third party to purchase the
leased property and thereby guarantee a minimum residual value of the leased
property to the lessor and the obligations of the Company under such lease or
related document to purchase or to cause a third party to purchase such leased
property..

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

        "Permitted Junior Securities" means Securities of the Company or any
other corporation that are equity securities or are subordinated in right of
payment to all Senior Indebtedness that may at the time be outstanding to
substantially the same extent as, or to a greater extent than, the Securities
are subordinated as provided in Article 10.

        "Pledge Agreement" means the Pledge Agreement, dated as of the date
hereof, between the Company and Union Bank of California, N.A., as pledge
trustee thereunder.

        "Principal Amount" of a Security means the Principal Amount as set forth
on the face of such Security.

        "Redemption Date" or "redemption date" means the date specified for
redemption of the Securities in accordance with the terms of the Securities and
this Indenture.


                                       2
<PAGE>   9


        "Redemption Price" or "redemption price" shall have the meaning set
forth in paragraph 6 of the reverse side of the form of Security set forth in
Exhibit A-1 of this Indenture.

        "Registration Rights Agreement" means the registration rights agreement,
dated July 26, 2001, between the Company and Merrill Lynch & Co., Merrill Lynch,
Pierce, Fenner & Smith Incorporated.

        "Responsible Officer" means, when used with respect to the Trustee, any
officer within the Corporate Trust Services Division of the Trustee, including
any first vice president, vice president, assistant vice president or trust
officer.

        "Restricted Security" means a Security required to bear the restrictive
legend set forth in the form of Security set forth in Exhibit A-1 of this
Indenture.

        "Rule 144A" means Rule 144A under the Securities Act (or any successor
provision), as it may be amended from time to time.

        "Sale Price" of Common Stock on any date means the closing per share
sale price (or, if no closing sale price is reported, the average of the bid and
ask prices or, if more than one in either case, the average of the average bid
and the average ask prices) on such date as reported in the composite
transactions for the principal United States securities exchange on which the
Common Stock is traded or, if the Common Stock is not listed on a United States
national or regional securities exchange, as reported by the National
Association of Securities Dealers Automated Quotation System or by the National
Quotation Bureau Incorporated. In the absence of such quotation, the Company
shall be entitled to determine the Sale Price on the basis of such quotations as
it considers appropriate.

        "SEC" means the Securities and Exchange Commission or any successor
thereto.

        "Securities" means any of the Company's Liquid Yield Option(TM) Notes
due 2031 (Zero Coupon-Subordinated), as amended or supplemented from time to
time, issued under this Indenture, the terms of which shall be substantially in
the form of the Security as set forth in Exhibit A-1 of this Indenture.

        "Securityholder" or "Holder" means a person in whose name a Security is
registered on the Registrar's books.

        "Senior Indebtedness" means, without duplication, the principal of (and
premium, if any) and unpaid interest on all present and future (i) indebtedness
of the Company for borrowed money, whether secured or unsecured, (ii)
obligations of the Company evidenced by bonds, debentures, notes or similar
instruments, (iii) obligations of the Company under (a) interest rate swaps,
caps, collars, options and similar arrangements, (b) any foreign exchange
contract, currency swap contract, futures contract, currency option contract, or
other foreign currency hedge or any other hedging arrangements, and (c) credit
swaps, caps, floors, collars and similar arrangements, (iv) indebtedness
incurred, assumed or guaranteed by the Company in connection with the
acquisition by it or a Subsidiary of any business, properties or assets (except
purchase-money indebtedness classified as accounts payable under generally
accepted accounting principles), (v) all obligations and liabilities, contingent
or otherwise, in respect of leases of the Company required, in conformity with
generally accepted accounting principles, to be accounted for as capitalized
lease obligations on the balance sheet of the Company and all obligations and
liabilities, contingent or otherwise, under any lease or related document,
including a purchase agreement, in connection with the lease of real property
which provides that the Company is contractually obligated to purchase or cause
a third party to purchase the leased property and thereby guarantee a minimum
residual value of the leased property to the lessor and the obligations of the
Company under such lease or related document to purchase or to cause a third
party to purchase such leased property, (vi) reimbursement obligations of the
Company in respect of letters of credit relating to indebtedness or other
obligations of the Company that qualify as indebtedness or obligations of the
kind referred to in clauses (i) through (v) above and (vii) obligations of the
Company under direct or indirect guarantees in respect of, and obligations
(contingent or otherwise) to purchase or otherwise acquire, or otherwise to
assure a creditor against loss in respect of, indebtedness or obligations of
others of the kinds referred to in clauses (i) through (vi) above, in each case
unless in the instrument creating or evidencing the indebtedness or obligation
or pursuant to which the same is outstanding it is provided that such
indebtedness or obligation is not superior in right of payment to the Securities
or that such indebtedness or obligation is subordinated to any other
indebtedness or obligation of the Company, unless


                                       3
<PAGE>   10

such indebtedness or obligation expressly provides that such indebtedness or
obligations are to be senior in right of payment to the Securities.

        "Senior Indebtedness Default" means the happening of an event of default
with respect to any Senior Indebtedness, as defined therein or in the instrument
under which the same is outstanding which, if occurring prior to the stated
maturity of such Senior Indebtedness, permits any holder thereof thereupon to
accelerate the maturity thereof.

        "Special Record Date" means for the payment of any Defaulted Interest,
the date fixed by the Trustee pursuant to Section 12.02.

        "Stated Maturity", when used with respect to any Security or any
installment of contingent interest thereon, means the date specified in such
Security as the fixed date on which an amount equal to the Principal Amount of
such Security or such installment of contingent interest is due and payable.

        "Subsidiary" means (i) a corporation, a majority of whose Capital Stock
with voting power, under ordinary circumstances, to elect directors is, at the
date of determination, directly or indirectly owned by the Company, by one or
more Subsidiaries of the Company or by the Company, and one or more Subsidiaries
of the Company, (ii) a partnership in which the Company, or a Subsidiary of the
Company, holds a majority interest in the equity capital or profits of such
partnership, or (iii) any other person (other than a corporation) in which the
Company, a Subsidiary of the Company, or the Company, and one or more
Subsidiaries of the Company, directly or indirectly, at the date of
determination, has (x) at least a majority ownership interest or (y) the power
to elect or direct the election of a majority of the directors or other
governing body of such person.

        "Tax Original Issue Discount" means the amount of ordinary interest
income on a Security that must be accrued as original issue discount for United
States Federal income tax purposes.

        "TIA" means the Trust Indenture Act of 1939 (15 U.S.C. Sections
77aaa-77bbbb) as in effect on the date of this Indenture, provided, however,
that in the event the TIA is amended after such date, TIA means, to the extent
required by any such amendment, the TIA as so amended.

        "trading day" means a day during which trading in securities generally
occurs on the National Association of Securities Dealers Automated Quotation
System or, if the Common Stock is not quoted on the National Association of
Securities Dealers Automated Quotation System, on the principal United States
Securities Exchange on which the Common Stock is then listed or quoted or if the
Common Stock is not quoted on either of the foregoing, the principal other
market on which the Common Stock is then listed or quoted or if the Common Stock
is not quoted on either of the foregoing, the principal other market on which
the Common Stock is then listed or quoted.

        "Trustee" means the party named as the "Trustee" in the first paragraph
of this Indenture until a successor replaces it pursuant to the applicable
provisions of this Indenture and, thereafter, shall mean such successor. The
foregoing sentence shall likewise apply to any subsequent such successor or
successors.

        SECTION 1.02 Other Definitions.

<TABLE>
<CAPTION>
                                                                                  Defined in
Term                                                                                Section
----                                                                              ----------
<S>                                                                               <C>
"Act".......................................................................        1.05(a)
"Agent Members".............................................................        2.12(e)
"Associate".................................................................        3.09(a)
"Average Sale Price"........................................................          11.01
"Bankruptcy Law"............................................................           6.01
"beneficial owner"..........................................................        3.09(a)
"Bid Solicitation Agent'....................................................           2.03
"cash"......................................................................        3.08(b)
"Change in Control".........................................................        3.09(a)
</TABLE>


                                       4
<PAGE>   11

<TABLE>
<S>                                                                               <C>
"Change in Control Purchase Date"...........................................        3.09(a)
"Change in Control Purchase Notice".........................................        3.09(c)
"Change in Control Purchase Price"..........................................       3.09(a)
"Company Notice"............................................................        3.08(e)
"Company Notice Date".......................................................        3.08(e)
"Conversion Agent"..........................................................           2.03
"Conversion Date"...........................................................          11.02
"Conversion Rate"...........................................................          11.01
"Custodian".................................................................           6.01
"Defaulted Interest"........................................................          12.02
"Depositary"................................................................        2.01(a)
"DTC".......................................................................        2.01(a)
"Event of Default"..........................................................           6.01
"Exchange Act"..............................................................        3.08(d)
"Ex-Dividend Date"..........................................................       11.08(a)
"Ex-Dividend Measurement Period"............................................          11.08
"Ex-Dividend Time"..........................................................          11.01
"Extraordinary Cash Dividend"...............................................          11.08
"group".....................................................................        3.09(a)
"Institutional Accredited Investors"........................................        2.01(b)
"Legal Holiday".............................................................          13.09
"Legend"....................................................................        2.06(f)
"LYON Market Price".........................................................    Exhibit A-1
"Market Price"..............................................................        3.08(d)
"Material Subsidiary".......................................................        6.01(a)
"noncontingent bond method".................................................    13.14(b)(1)
"Notice of Default".........................................................           6.01
"Paying Agent"..............................................................           2.03
"permitted holder"..........................................................        3.09(a)
"Purchase Date".............................................................        3.08(a)
"Purchase Notice"...........................................................     3.08(a)(1)
"Purchase Price"............................................................        3.08(a)
"QIBs"......................................................................        2.01(a)
"Registrar".................................................................           2.03
"Relevant Cash Dividends"...................................................          11.08
"Rights"....................................................................          11.19
"Rights Agreement"..........................................................          11.19
"Rule 144A Information".....................................................           4.06
"Securities Act"............................................................        3.08(d)
"Special Record Date".......................................................          12.02
"Time of Determination".....................................................          11.01
</TABLE>


        SECTION 1.03 Incorporation by Reference of Trust Indenture Act. Whenever
this Indenture refers to a provision of the TIA, the provision is incorporated
by reference in and made a part of this Indenture. The following TIA terms used
in this Indenture have the following meanings:

        "Commission" means the SEC.

        "indenture securities" means the Securities.

        "indenture security holder" means a Securityholder.

        "indenture to be qualified" means this Indenture.


                                       5
<PAGE>   12


        "indenture trustee" or "institutional trustee" means the Trustee.

        "obligor" on the indenture securities means the Company.

        All other TIA terms used in this Indenture that are defined by the TIA,
defined by TIA reference to another statute or defined by SEC rule and not
otherwise defined herein have the meanings assigned to them by such definitions.

        SECTION 1.04 Rules of Construction. Unless the context otherwise
requires:

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

               (b)    an accounting term not otherwise defined has the meaning
                      assigned to it in accordance with generally accepted
                      accounting principles as in effect from time to time;

               (c)    "or" is not exclusive;

               (d)    "including" means including, without limitation; and

               (e)    words in the singular include the plural, and words in the
                      plural include the singular.

        SECTION 1.05 Acts of Holders.

               (a)    Any request, demand, authorization, direction, notice,
                      consent, waiver or other action provided by this Indenture
                      to be given or taken by Holders may be embodied in and
                      evidenced by one or more instruments of substantially
                      similar tenor signed by such Holders in person or by agent
                      duly appointed in writing; and, except as herein otherwise
                      expressly provided, such action shall become effective
                      when such instrument or instruments are delivered to the
                      Trustee and, where it is hereby expressly required, to the
                      Company. Such instrument or instruments (and the action
                      embodied therein and evidenced thereby) are herein
                      sometimes referred to as the "Act" of 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
                      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 such
                      officer the execution thereof. Where such execution is by
                      a signer acting in a capacity other than such signer's
                      individual capacity, such certificate or affidavit shall
                      also constitute sufficient proof of such signer's
                      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
                      register maintained by the Registrar.

               (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
                      to be done by the Trustee, the Company in reliance
                      thereon, whether or not notation of such action is made
                      upon such Security.


                                       6
<PAGE>   13


               (e)    If the Company shall solicit from the Holders any request,
                      demand, authorization, direction, notice, consent, waiver
                      or other Act, the Company may, at its option, by or
                      pursuant to a resolution of the Board of Directors of the
                      Company fix in advance a record date for the determination
                      of Holders entitled to give such request, demand,
                      authorization, direction, notice, consent, waiver or other
                      Act, but the Company shall not have any obligation to do
                      so. If such a record date is fixed, such request, demand,
                      authorization, direction, notice, consent, waiver or other
                      Act may be given before or after such record date, but
                      only the Holders of record at the close of business on
                      such record date shall be deemed to be Holders for the
                      purposes of determining whether Holders of the requisite
                      proportion of outstanding Securities have authorized or
                      agreed or consented to such request, demand,
                      authorization, direction, notice, consent, waiver or other
                      Act, and for that purpose the outstanding Securities shall
                      be computed as of such record date; provided that no such
                      authorization, agreement or consent by the Holders on such
                      record date shall be deemed effective unless it shall
                      become effective pursuant to the provisions of this
                      Indenture not later than six months after the record date.

                            ARTICLE 2 THE SECURITIES

        SECTION 2.01 Form and Dating. The Securities and the Trustee's
certificate of authentication shall be substantially in the form of Exhibit A-1
which is a part of this Indenture. The Securities may have notations, legends or
endorsements required by law, stock exchange rule or usage; provided that any
such notation, legend or endorsement required by usage is in a form acceptable
to the Company and are not inconsistent with the provisions of this Indenture.
The Company shall provide any such notations, legends or endorsements to the
Trustee in writing. Each Security shall be dated the date of its authentication.

            (b) 144A Global Securities. Securities offered and sold to
"qualified institutional buyers" as defined in Rule 144A ("QIBs") in reliance on
Rule 144A shall be issued, initially in the form of a 144A Global Security,
which shall be deposited with the Trustee at its Corporate Trust Office, as
custodian for the Depositary and registered in the name of The Depository Trust
Company ("DTC") or the nominee thereof (such depositary, or any successor
thereto, and any such nominee being hereinafter referred to as the
"Depositary"), duly executed by the Company and authenticated by the Trustee as
hereinafter provided and with appropriate legends. The aggregate Principal
Amount of the 144A Global Securities may from time to time be increased or
decreased by adjustments made on the records of the Trustee and the Depositary
as hereinafter provided.

            (c) Certificated Securities. Except as provided in Section 2.12,
owners of beneficial interests in Global Securities will not be entitled to
receive physical delivery of Securities in definitive form.

            (d) Global Securities in General. Each Global Security shall
represent such of the outstanding Securities as shall be specified therein and
each shall provide that it shall represent the aggregate Principal Amount of
outstanding Securities from time to time endorsed thereon and that the aggregate
Principal Amount of outstanding Securities represented thereby may from time to
time be reduced or increased, as appropriate, to reflect exchanges, redemptions
and conversions.

        Any adjustment of the aggregate Principal Amount of a Global Security to
reflect the amount of any increase or decrease in the Principal Amount of
outstanding Securities represented thereby shall be made by the Trustee in
accordance with instructions given by the Holder thereof as required by Section
2.12 hereof and shall be made on the records of the Trustee and the Depositary.

            (e) Book-Entry Provisions. This Section 2.01(d) shall apply only to
Global Securities deposited with or on behalf of the Depositary.

        The Company shall execute and the Trustee shall, in accordance with this
Section 2.01(d), authenticate and deliver initially one or more Global
Securities that (a) shall be registered in the name of the Depositary, (b) shall
be delivered by the Trustee to the Depositary or pursuant to the Depositary's
instructions and (c) shall bear legends substantially to the following effect:


                                       7
<PAGE>   14

        "UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF
        THE DEPOSITORY TRUST COMPANY TO THE ISSUER OR ITS AGENT FOR REGISTRATION
        OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS
        REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS
        REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST
        COMPANY (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR TO SUCH OTHER
        ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
        TRUST COMPANY), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
        OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER
        HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

        TRANSFERS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS, IN
        WHOLE BUT NOT IN PART, TO NOMINEES OF THE DEPOSITORY TRUST COMPANY OR TO
        A SUCCESSOR THEREOF OR SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF
        PORTIONS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS MADE IN
        ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN ARTICLE TWO OF THE
        INDENTURE REFERRED TO ON THE REVERSE HEREOF."

        SECTION 2.02 Execution and Authentication. The Securities shall be
executed on behalf of the Company by any Officer of the Company. The signature
of the Officer of the Company on the Securities may be manual or a facsimile
thereof.

        Securities bearing the manual or facsimile signatures of an individual
who was at the time of the execution of the Securities an Officer of the Company
shall bind the Company notwithstanding that such individual has ceased to hold
such office prior to the authentication and delivery of such Securities or did
not hold such office at the date of authentication of such Securities.

        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 duly
executed by the Trustee by manual signature of a Responsible Officer, and such
certificate upon any Security shall be conclusive evidence, and the only
evidence, that such Security has been duly authenticated and delivered
hereunder.

        The Trustee shall authenticate and deliver Securities for original issue
in an aggregate Principal Amount of up to $880,000,000 upon a Company Order
without any further action by the Company. The aggregate Principal Amount of
Securities outstanding at any time may not exceed the amount set forth in the
foregoing sentence, except as provided in Section 2.07.

        The Securities shall be issued only in registered form without coupons
and only in denominations of $1,000 of Principal Amount and any integral
multiple thereof.

        SECTION 2.03 Registrar, Paying Agent, Conversion Agent and Bid
Solicitation Agent. The Company shall maintain an office or agency where
Securities may be presented for registration of transfer or for exchange
("Registrar"), an office or agency where Securities may be presented for
purchase or payment ("Paying Agent") and an office or agency where Securities
may be presented for conversion ("Conversion Agent") as set forth in Section
4.05 herein. The Company shall also appoint a bid solicitation agent (the "Bid
Solicitation Agent") to act pursuant to paragraph 5 of the Securities. The
Registrar shall keep a register of the Securities and of their transfer and
exchange. The Company may have one or more co-registrars, one or more additional
paying agents and one or more additional conversion agents. The term Paying
Agent includes any additional paying agent, including any named pursuant to
Section 4.05. The term Conversion Agent includes any additional conversion
agent, including any named pursuant to Section 4.05.

        The Company shall enter into an appropriate agency agreement with any
Registrar or co-registrar, Paying Agent, Conversion Agent or Bid Solicitation
Agent (other than the Trustee). The agreement shall implement the provisions of
this Indenture that relate to such agent. The Company shall notify the Trustee
of the name and address


                                       8
<PAGE>   15

of any such agent. If the Company fails to maintain a Registrar, Paying Agent,
Conversion Agent or Bid Solicitation Agent, the Trustee shall act as such and
shall be entitled to appropriate compensation therefor pursuant to Section 7.07.
The Company or any Subsidiary or an Affiliate of either of them may act as
Paying Agent, Registrar, Conversion Agent or co-registrar. None of the Company
or any Subsidiary of the Company or any Affiliate of any of them may act as Bid
Solicitation Agent.

        The Company initially appoints the Trustee as Registrar, Conversion
Agent, Paying Agent, Bid Solicitation Agent and agent for service of demands and
notices in connection with the Securities. The Trustee shall be entitled to the
same rights and indemnities in its capacity as Registrar, Conversion Agent,
Paying Agent, Bid Solicitation Agent and agent for service of demands and
notices as in its capacity as Trustee.

        SECTION 2.04 Paying Agent to Hold Money and Securities in Trust. Except
as otherwise provided herein, on or prior to each due date of payments in
respect of any Security, the Company shall deposit with the Paying Agent a sum
of money (in immediately available funds if deposited on the due date) or Common
Stock sufficient to make such payments when so becoming due. The Company shall
require each Paying Agent (other than the Trustee) to agree in writing that the
Paying Agent shall hold in trust for the benefit of Securityholders or the
Trustee all money and Common Stock held by the Paying Agent for the making of
payments in respect of the Securities and shall notify the Trustee of any
default by the Company in making any such payment. At any time during the
continuance of any such default, the Paying Agent shall, upon the written
request of the Trustee, forthwith pay to the Trustee all money and Common Stock
so held in trust. If the Company or a Subsidiary or an Affiliate thereof acts as
Paying Agent, it shall segregate the money and Common Stock held by it as Paying
Agent and hold such assets as a separate trust fund. The Company at any time may
require a Paying Agent to distribute all money and Common Stock held by it to
the Trustee and to account for any funds and Common Stock disbursed by it. Upon
doing so, the Paying Agent shall have no further liability for the money or
Common Stock.

        SECTION 2.05 Securityholder Lists. The Trustee shall preserve in as
current a form as is reasonably practicable the most recent list available to it
of the names and addresses of Securityholders. If the Trustee is not the
Registrar, the Company shall cause to be furnished to the Trustee at least
semiannually on January 26 and July 26 of each year a listing of Securityholders
dated within 15 days of the date on which the list is furnished and at such
other times as the Trustee may reasonably request in writing a list in such form
and as of such date as the Trustee may reasonably require of the names and
addresses of Securityholders.

        SECTION 2.06 Transfer and Exchange. Subject to Section 2.12 hereof,

            (a) upon surrender for registration of transfer of any Security,
together with a written instrument of transfer satisfactory to the Registrar
duly executed by the securityholder or such Securityholder's attorney duly
authorized in writing, at the office or agency of the Company designated as
Registrar or co-registrar pursuant to Section 2.03, the Company shall execute,
and the Trustee upon receipt of a Company Order shall authenticate and deliver,
in the name of the designated transferee or transferees, one or more new
Securities of any authorized denomination or denominations, of a like aggregate
Principal Amount. The Company shall not charge a service charge for any
registration of transfer or exchange, but the Company may require payment of a
sum sufficient to pay all taxes, assessments or other governmental charges that
may be imposed in connection with the transfer or exchange of the Securities
from the Securityholder requesting such transfer or exchange.

        At the option of the Holder, Securities may be exchanged for other
Securities of any authorized denomination or denominations, of a like aggregate
Principal Amount, upon surrender of the Securities to be exchanged, together
with a written instrument of transfer satisfactory to the Registrar duly
executed by the Securityholder or such Securityholder's attorney duly authorized
in writing, at such office or agency. Whenever any Securities are so surrendered
for exchange, the Company shall execute, and the Trustee upon receipt of a
Company Order shall authenticate and deliver, the Securities which the Holder
making the exchange is entitled to receive.

        The Company shall not be required to make, and the Registrar need not
register, transfers or exchanges of Securities selected for redemption (except,
in the case of Securities to be redeemed in part, the portion thereof not to be
redeemed) or any Securities in respect of which a Purchase Notice or Change in
Control Purchase Notice has been given and not withdrawn by the Holder thereof
in accordance with the terms of this Indenture (except, in the


                                       9
<PAGE>   16

case of Securities to be purchased in part, the portion thereof not to be
purchased) or any Securities for a period of 15 days before the mailing of a
notice of redemption of Securities to be redeemed.

            (b) Notwithstanding any provision to the contrary herein, so long as
a Global Security remains outstanding and is held by or on behalf of the
Depositary, transfers of a Global Security, in whole or in part, shall be made
only in accordance with Section 2.12 and this Section 2.06(b). Transfers of a
Global Security shall be limited to transfers of such Global Security in whole,
or in part, to nominees of the Depositary or to a successor of the Depositary or
such successor's nominee.

            (c) Successive registrations and registrations of transfers and
exchanges as aforesaid may be made from time to time as desired, and each such
registration shall be noted on the register for the Securities.

            (d) Any Registrar appointed pursuant to Section 2.03 hereof shall
provide to the Trustee such information as the Trustee may reasonably require in
connection with the delivery by such Registrar of Securities upon transfer or
exchange of Securities.

            (e) No Registrar shall be required to make registrations of transfer
or exchange of Securities during any periods designated in the text of the
Securities or in this Indenture as periods during which such registration of
transfers and exchanges need not be made.

            (f) If Securities are issued upon the transfer, exchange or
replacement of Securities subject to restrictions on transfer and bearing the
legends set forth on the form of Security attached hereto as Exhibit A-1 setting
forth such restrictions (collectively, the "Legend"), or if a request is made to
remove the Legend on a Security, the Securities so issued shall bear the Legend,
or the Legend shall not be removed, as the case may be, unless there is
delivered to the Company and the Registrar such satisfactory evidence, which
shall include an Opinion of Counsel, as may be reasonably required by the
Company and the Registrar, that neither the Legend nor the restrictions on
transfer set forth therein are required to ensure that transfers thereof comply
with the provisions of Rule 144A or Rule 144 under the Securities Act or that
such Securities are not "restricted" within the meaning of Rule 144 under the
Securities Act. Upon (i) provision of such satisfactory evidence, or (ii)
notification by the Company to the Trustee and Registrar of the sale of such
Security pursuant to a registration statement that is effective at the time of
such sale, the Trustee, at the written direction of the Company , shall
authenticate and deliver a Security that does not bear the Legend. If the Legend
is removed from the face of a Security pursuant to the terms of this section (f)
and the Security is subsequently held by an Affiliate of the Company, the Legend
shall be reinstated by the Company.

        The Trustee and the Registrar shall have no obligation or duty to
monitor, determine or inquire as to compliance with any restrictions on transfer
imposed under this Indenture or under applicable law with respect to any
transfer of any interest in any Security (including any transfers between or
among Depositary participants or beneficial owners of interests in any Global
Security) other than to require delivery of such certificates and other
documentation or evidence as are expressly required by, and to do so if and when
expressly required by the terms of, this Indenture, and to examine the same to
determine substantial compliance as to form with the express requirements hereof
and shall promptly notify the party delivering the same of any non-compliance.

        SECTION 2.07 Replacement Securities. If (a) any mutilated Security is
surrendered to the Trustee, or (b) the Company and the Trustee receive evidence
to their satisfaction of the destruction, loss or theft of any Security, and
there is delivered to the Company and the Trustee such security or indemnity as
may be required by them to save each 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 upon its written request the
Trustee shall authenticate and deliver, in exchange for any such mutilated
Security or in lieu of any such destroyed, lost or stolen Security, a new
Security of like tenor and Principal Amount, bearing a number not
contemporaneously outstanding.

        In case any such mutilated, destroyed, lost or stolen Security has
become or is about to become due and payable, or is about to be purchased by the
Company pursuant to Article 3 hereof, the Company in its discretion may, instead
of issuing a new Security, pay or purchase such Security, as the case may be.


                                       10
<PAGE>   17

        Upon the issuance of any new Securities 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 issued pursuant to this Section in lieu of any
mutilated, 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 benefits of this Indenture equally and proportionately with any
and all other Securities 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 2.08 Outstanding Securities; Determinations of Holders' Action.
Securities outstanding at any time are all the Securities authenticated by the
Trustee except for those cancelled by it, those delivered to it pursuant to
Section 2.07 for cancellation and those described in this Section 2.08 as not
outstanding. A Security does not cease to be outstanding because the Company or
an Affiliate of the Company holds the Security; provided, however, that in
determining whether the Holders of the requisite Principal Amount of Securities
have given or concurred in any request, demand, authorization, direction,
notice, consent or waiver hereunder, Securities owned by the Company or any
other obligor upon the Securities or any Affiliate of the Company or such other
obligor shall be disregarded and deemed not to be outstanding, except that, in
determining whether the Trustee shall be protected in relying upon any such
request, demand, authorization, direction, notice, consent or waiver, only
Securities which a Responsible Officer of the Trustee actually knows to be so
owned shall be so disregarded. Subject to the foregoing, only Securities
outstanding at the time of such determination shall be considered in any such
determination (including, without limitation, determinations pursuant to
Articles 6 and 9).

        If a Security is replaced pursuant to Section 2.07, it ceases to be
outstanding unless the Trustee receives proof satisfactory to it that the
replaced Security is held by a bona fide purchaser. A mutilated Security ceases
to be outstanding upon surrender of such Security and replacement thereof
pursuant to Section 2.07.

        If the Paying Agent holds, in accordance with this Indenture, on a
Redemption Date, or on the Business Day following the Purchase Date or a Change
in Control Purchase Date, or on Stated Maturity, money or securities, if
permitted hereunder, sufficient to pay Securities payable on that date, then
immediately after such Redemption Date, Purchase Date, Change in Control
Purchase Date or Stated Maturity, as the case may be, such Securities shall
cease to be outstanding and contingent interest, if any, on such Securities
shall cease to accrue; provided, that if such Securities are to be redeemed,
notice of such redemption has been duly given pursuant to this Indenture.

        If a Security is converted in accordance with Article 11, then from and
after the time of conversion on the Conversion Date, such Security shall cease
to be outstanding and contingent interest, if any, shall cease to accrue on such
Security, whether or not the Security is delivered to the Paying Agent.

        SECTION 2.09 Temporary Securities. Subject to Section 2.12 hereof,
pending the preparation of definitive Securities, the Company may execute, and
upon Company Order the Trustee shall authenticate and deliver, temporary
Securities, in an amount specified in such Company Order or an Officer's
Certificate, 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, Legends and other variations
as the officers executing such Securities may determine, as conclusively
evidenced by their execution of such Securities.

        If temporary Securities are issued, the Company will cause definitive
Securities to be prepared without unreasonable delay. After the preparation of
definitive Securities, the temporary Securities shall be exchangeable for
definitive Securities upon surrender of the temporary Securities at the office
or agency of the Company designated for such purpose pursuant to Section 2.03,
without charge to the Holder. Upon surrender for cancellation of any one or more
temporary Securities the Company shall execute and upon Company Order the
Trustee shall authenticate and deliver in exchange therefor a like Principal
Amount of definitive Securities of authorized


                                       11
<PAGE>   18

denominations. Until so exchanged the temporary Securities shall in all respects
be entitled to the same benefits under this Indenture as definitive Securities.

        SECTION 2.10 Cancellation. All Securities surrendered for payment,
purchase by the Company pursuant to Article 3, conversion, redemption or
registration of transfer or exchange shall, if surrendered to any person other
than the Trustee, be delivered to the Trustee and shall be promptly cancelled by
it. The Company may at any time deliver to the Trustee for cancellation any
Securities previously authenticated and delivered hereunder which the Company
may have acquired in any manner whatsoever, and all Securities so delivered
shall be promptly cancelled by the Trustee. The Company may not issue new
Securities to replace Securities it has paid or delivered to the Trustee for
cancellation or that any Holder has converted pursuant to Article 11. 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 the Trustee's customary procedure.

        SECTION 2.11 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 the Security or the payment of any Redemption Price, Purchase Price
or Change in Control Purchase Price in respect thereof, and contingent interest,
if any thereon, for the purpose of conversion and for all other purposes
whatsoever, whether or not such Security be overdue, and neither the Company,
the Trustee nor any agent of the Company or the Trustee shall be affected by
notice to the contrary.

        SECTION 2.12 Global Securities.

            (a) Transfer of Global Security. Notwithstanding any other
provisions of this Indenture or the Securities, transfers of a Global Security,
in whole or in part, shall be made only in accordance with Section 2.06 and
Section 2.12(a). A Global Security may not be transferred, in whole or in part,
to any Person other than the Depositary or a nominee or any successor thereof,
and no such transfer to any such other Person may be registered; provided that
this clause (a) shall not prohibit any transfer of a Security that is issued in
exchange for a Global Security but is not itself a Global Security. No transfer
of a Security to any Person shall be effective under this Indenture unless and
until such Security has been registered in the name of such Person.

            (b) Subject to the succeeding paragraph, every Security shall be
subject to the restrictions on transfer provided in the Legend including the
delivery of a certification or an opinion of counsel, if so requested by the
Company or the Registrar.

            (c) The restrictions imposed by the Legend upon the transferability
of any Security shall cease and terminate when such Security has been sold
pursuant to an effective registration statement under the Securities Act or
transferred in compliance with Rule 144 under the Securities Act (or any
successor provision thereto) or, if earlier, upon the expiration of the holding
period applicable to sales thereof under Rule 144(k) under the Securities Act
(or any successor provision). Any Security as to which such restrictions on
transfer shall have expired in accordance with their terms or shall have
terminated may, upon a surrender of such Security for exchange to the Registrar
in accordance with the provisions of this Section 2.12 (accompanied, in the
event that such restrictions on transfer have terminated by reason of a transfer
in compliance with Rule 144 or any successor provision, by an opinion of counsel
having substantial experience in practice under the Securities Act and otherwise
reasonably acceptable to the Company, addressed to the Company and the Registrar
and in form acceptable to the Company, to the effect that the transfer of such
Security has been made in compliance with Rule 144 or such successor provision),
be exchanged for a new Security, of like tenor and aggregate Principal Amount,
which shall not bear the restrictive Legend. The Company shall inform the
Trustee of the effective date of any registration statement registering the
Securities under the Securities Act. The Trustee and the Registrar shall not be
liable for any action taken or omitted to be taken by it in good faith in
accordance with the aforementioned opinion of counsel or registration statement.


                                       12
<PAGE>   19

            (d) As used in the preceding two paragraphs of this Section 2.12,
the term "transfer" encompasses any sale, pledge, transfer, hypothecation or
other disposition of any Security.

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

            (1) Notwithstanding any other provisions of this Indenture or the
            Securities, except as provided in Section 2.12(a)(ii), a Global
            Security shall not be exchanged in whole or in part for a Security
            registered in the name of any Person other than the Depositary or
            one or more nominees thereof, provided that a Global Security may be
            exchanged for Securities registered in the names of any person
            designated by the Depositary in the event that (i) the Depositary
            has notified the Company that it is unwilling or unable to continue
            as Depositary for such Global Security or such Depositary has ceased
            to be a "clearing agency" registered under the Exchange Act, and a
            successor Depositary is not appointed by the Company within 90 days,
            (ii) the Company decides to discontinue the use of the system of
            book-entry transfer through the Depositary (or any successor
            Depositary) or (iii) an Event of Default has occurred and is
            continuing with respect to the Securities. Any Global Security
            exchanged pursuant to clause (i) above shall be so exchanged in
            whole and not in part, and any Global Security exchanged pursuant to
            clause (iii) above may be exchanged in whole or from time to time in
            part as directed by the Depositary. Any Security issued in exchange
            for a Global Security or any portion thereof shall be a Global
            Security; provided that any such Security so issued that is
            registered in the name of a Person other than the Depositary or a
            nominee thereof shall not be a Global Security.

            (2) Securities issued in exchange for a Global Security or any
            portion thereof shall be issued in definitive, fully registered
            form, without interest coupons, shall have an aggregate Principal
            Amount equal to that of such Global Security or portion thereof to
            be so exchanged, shall be registered in such names and be in such
            authorized denominations as the Depositary shall designate and shall
            bear the applicable Legends provided for herein. Any Global Security
            to be exchanged in whole shall be surrendered by the Depositary to
            the Trustee, as Registrar. With regard to any Global Security to be
            exchanged in part, either such Global Security shall be so
            surrendered for exchange or, if the Trustee is acting as custodian
            for the Depositary or its nominee with respect to such Global
            Security, the Principal Amount thereof shall be reduced, by an
            amount equal to the portion thereof to be so exchanged, by means of
            an appropriate adjustment made on the records of the Trustee. Upon
            any such surrender or adjustment, the Trustee shall authenticate and
            deliver the Security issuable on such exchange to or upon the order
            of the Depositary or an authorized representative thereof.

            (3) Subject to the provisions of clause (5) below, the registered
            Holder may grant proxies and otherwise authorize any Person,
            including Agent Members (as defined below) and persons that may hold
            interests through Agent Members, to take any action which a holder
            is entitled to take under this Indenture or the Securities.

            (4) In the event of the occurrence of any of the events specified in
            clause (1) above, the Company will promptly make available to the
            Trustee a reasonable supply of Certificated Securities in
            definitive, fully registered form, without interest coupons.

            (5) Neither any members of, or participants in, the Depositary
            (collectively, the "Agent Members") nor any other Persons on whose
            behalf Agent Members may act shall have any rights under this
            Indenture with respect to any Global Security registered in the name
            of the Depositary or any nominee thereof, or under any such Global
            Security, and the Depositary or such nominee, as the case may be,
            may be treated by the Company, the Trustee and any agent of the
            Company or the Trustee as the absolute owner and holder of such
            Global Security for all purposes whatsoever. Notwithstanding the
            foregoing, nothing herein shall prevent the Company or the Trustee
            or any agent of the Company or the Trustee from giving effect to any
            written certification, proxy or other authorization furnished by the
            Depositary or such nominee, as the case may be, or impair, as


                                       13
<PAGE>   20


            between the Depositary, its Agent Members and any other person on
            whose behalf an Agent Member may act, the operation of customary
            practices of such Persons governing the exercise of the rights of a
            holder of any Security.

        SECTION 2.13 CUSIP Numbers. The Company in issuing the Securities may
use one or more "CUSIP" numbers (if then generally in use), and, if so, the
Trustee shall use such "CUSIP" numbers in notices of redemption as a convenience
to Holders; provided that any such notice may state that no representation is
made as to the correctness of such 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 3 REDEMPTION AND PURCHASES

        SECTION 3.01 Right to Redeem; Notices to Trustee.

        The Company, at its option, may redeem the Securities in accordance with
the provisions of paragraphs 6 and 8 of the Securities. If the Company elects to
redeem Securities pursuant to paragraph 6 of the Securities, it shall notify the
Trustee in writing of the Redemption Date, the Principal Amount of Securities to
be redeemed, the Redemption Price and the amount of contingent interest, if any,
payable on the Redemption Date.

        The Company shall give the notice to the Trustee provided for in this
Section 3.01 by a Company Order at least 30 days before the Redemption Date
(unless a shorter notice shall be satisfactory to the Trustee in its sole
discretion).

        SECTION 3.02 Selection of Securities to Be Redeemed.

        If less than all the Securities are to be redeemed, the Trustee shall
select the Securities to be redeemed, pro rata based on ownership thereof or by
lot or by any other method the Trustee considers fair and appropriate (so long
as such method is not prohibited by the rules of any stock exchange on which the
Securities are then listed and complies with applicable laws). The Trustee shall
make the selection at least 15 days but not more than 60 days before the
Redemption Date from outstanding Securities not previously called for
redemption. The Trustee may select for redemption portions of the Principal
Amount of Securities that have denominations larger than $1,000.

        Securities and any portions thereof that the Trustee selects shall be in
Principal Amounts at Maturity of $1,000 or any integral multiple of $1,000.
Provisions of this Indenture that apply to Securities called for redemption also
apply to portions of Securities called for redemption. The Trustee shall notify
the Company promptly of the Securities or portions of Securities to be redeemed.

        If any 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. Securities which have
been converted during a selection of Securities to be redeemed may be treated by
the Trustee as outstanding for the purpose of such selection.

        SECTION 3.03 Notice of Redemption.

        At least 15 days but not more than 60 days before a Redemption Date, the
Company shall mail a notice of redemption by first-class mail, postage prepaid,
to each Holder of Securities to be redeemed at its registered address.

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

            (1) the Redemption Date;


                                       14
<PAGE>   21


            (2) the Redemption Price and, to the extent known at the time of
            such notice, the amount of contingent interest, if any, payable on
            the Redemption Date;

            (3) the Conversion Rate;

            (4) the name and address of the Paying Agent and Conversion Agent;

            (5) that Securities called for redemption may be converted at any
            time before the close of business on the second Business Day
            immediately preceding the Redemption Date;

            (6) that Holders who want to convert Securities must satisfy the
            requirements set forth in paragraph 10 of the Securities;

            (7) that Securities called for redemption must be surrendered to the
            Paying Agent to collect the Redemption Price and contingent
            interest, if any;

            (8) if fewer than all the outstanding Securities are to be redeemed,
            the certificate number and Principal Amounts at Maturity of the
            particular Securities to be redeemed;

            (9) that, unless the Company defaults in making payment of such
            Redemption Price and contingent interest, if any, on Securities
            called for redemption will cease to accrue on and after the
            Redemption Date; and

            (10) the CUSIP number of the Securities.

        At the Company's request, the Trustee shall give the notice of
redemption in the Company's name and at the Company's expense, provided that the
Company makes such request at least 15 days (unless a shorter period shall be
acceptable to the Trustee in its sole discretion) prior to the date such notice
of redemption must be mailed.

        SECTION 3.04 Effect of Notice of Redemption. Once notice of redemption
is given pursuant to Section 3.03, Securities called for redemption become due
and payable on the Redemption Date and at the Redemption Price (together with
accrued contingent interest, if any) stated in the notice except for Securities
which are converted in accordance with the terms of this Indenture. Upon
surrender to the Paying Agent, such Securities shall be paid at the Redemption
Price (together with accrued contingent interest, if any) stated in the notice.

        SECTION 3.05 Deposit of Redemption Price. Prior to 10:00 a.m. (New York
City time), on the Redemption Date, the Company shall deposit with the Paying
Agent (or if the Company or a Subsidiary of the Company or an Affiliate of any
of them is the Paying Agent, shall segregate and hold in trust) money sufficient
to pay the Redemption Price of, and any accrued and unpaid contingent interest
with respect to, all Securities to be redeemed on that date other than
Securities or portions of Securities called for redemption which on or prior
thereto have been delivered by the Company to the Trustee for cancellation or
have been converted. The Paying Agent shall as promptly as practicable return to
the Company any money, not required for that purpose because of conversion of
Securities pursuant to Article 11. If such money is then held by the Company in
trust and is not required for such purpose it shall be discharged from such
trust.

        SECTION 3.06 Securities Redeemed in Part. Upon surrender of a Security
that is redeemed in part, the Company shall execute and the Trustee shall
authenticate and deliver to the Holder a new Security in an authorized
denomination equal in Principal Amount to the unredeemed portion of the Security
surrendered.

        SECTION 3.07 Conversion Arrangement on Call for Redemption. In
connection with any redemption of Securities, the Company may arrange for the
purchase and conversion of any Securities called for redemption by an agreement
with one or more investment banking institutions or other purchasers to purchase
such Securities by paying to the Trustee in trust for the Securityholders, on or
prior to 10:00 a.m. New York City time on


                                       15
<PAGE>   22


the Redemption Date, an amount that, together with any amounts deposited with
the Trustee by the Company for the redemption of such Securities, is not less
than the Redemption Price of, and any accrued and unpaid contingent interest
with respect to, such Securities. Notwithstanding anything to the contrary
contained in this Article 3, the obligation of the Company to pay the Redemption
Prices of such Securities shall be deemed to be satisfied and discharged to the
extent such amount is so paid by such purchasers. If such an agreement is
entered into, any Securities not duly surrendered for conversion by the Holders
thereof may, at the option of the Company, be deemed, to the fullest extent
permitted by law, acquired by such purchasers from such Holders and
(notwithstanding anything to the contrary contained in Article 11) surrendered
by such purchasers for conversion, all as of immediately prior to the close of
business on the Business Day prior to the Redemption Date, subject to payment of
the above amount as aforesaid. The Trustee shall hold and pay to the Holders
whose Securities are selected for redemption any such amount paid to it for
purchase and conversion in the same manner as it would moneys deposited with it
by the Company for the redemption of Securities. Without the Trustee's prior
written consent, no arrangement between the Company and such purchasers for the
purchase and conversion of any Securities shall increase or otherwise affect any
of the powers, duties, responsibilities or obligations of the Trustee as set
forth in this Indenture, and the Company agrees to indemnify the Trustee from,
and hold it harmless against, any loss, liability or expense arising out of or
in connection with any such arrangement for the purchase and conversion of any
Securities between the Company and such purchasers, including the costs and
expenses incurred by the Trustee in the defense of any claim or liability
arising out of or in connection with the exercise or performance of any of its
powers, duties, responsibilities or obligations under this Indenture.

        SECTION 3.08 Purchase of Securities at Option of the Holder.

            (a) General. Securities shall be purchased by the Company pursuant
to paragraph 7 of the Securities as of July 26, 2002, July 26, 2006, July 26,
2011, July 26, 2016, July 26, 2021 and July 26, 2026 (each, a "Purchase Date"),
at the purchase price of $1,000 per $1,000 of Principal Amount of a Security
(the "Purchase Price"), at the option of the Holder thereof, upon:

            (i) delivery to the Paying Agent, by the Holder of a written notice
            of purchase (a "Purchase Notice") at any time from the opening of
            business on the date that is at least 20 Business Days prior to a
            Purchase Date until the close of business on the second Business Day
            immediately preceding such Purchase Date stating:

               (A) the certificate number and CUSIP number of the Security which
               the Holder will deliver to be purchased,

               (B) the portion of the Principal Amount of the Security which the
               Holder will deliver to be purchased, which portion must be a
               Principal Amount of $1,000 or any integral multiple thereof,

               (C) that such Security shall be purchased as of the Purchase Date
               pursuant to the terms and conditions specified in (i) paragraph 7
               of the Securities and (ii) this Indenture, and

               (D) with respect to a purchase on any Purchase Date other than
               July 26, 2002, in the event the Company elects, pursuant to
               Section 3.08(b), to pay the Purchase Price to be paid as of such
               Purchase Date, in whole or in part, in shares of Common Stock but
               such portion of the Purchase Price shall ultimately be payable to
               such Holder entirely in cash because any of the conditions to
               payment of the Purchase Price (or a portion thereof) in Common
               Stock is not satisfied prior to the close of business on such
               Purchase Date, as set forth in Section 3.08(d), whether such
               Holder elects (i) to withdraw such Purchase Notice as to some or
               all of the Securities to which such Purchase Notice relates
               (stating the Principal Amount and certificate numbers of the
               Securities as to which such withdrawal shall relate), or (ii) to
               receive cash in respect of the entire Purchase Price for all
               Securities (or portions thereof) to which such Purchase Notice
               relates; and


                                       16
<PAGE>   23

            (b) delivery of such Security to the Paying Agent prior to, on or
after the Purchase Date (together with all necessary endorsements) at the
offices of the Paying Agent, such delivery being a condition to receipt by the
Holder of the Purchase Price therefor; provided, however, that such Purchase
Price shall be so paid pursuant to this Section 3.08 only if the Security so
delivered to the Paying Agent shall conform in all respects to the description
thereof in the related Purchase Notice, as determined by the Company and such
Purchase Notice shall not be validly withdrawn by the Holder.

        If a Holder, in such Holder's Purchase Notice and in any written notice
of withdrawal delivered by such Holder pursuant to the terms of Section 3.10,
fails to indicate such Holder's choice with respect to the election set forth in
clause (D) of Section 3.08(a)(1), such Holder shall be deemed to have elected to
receive cash in respect of the Purchase Price for all Securities subject to such
Purchase Notice in the circumstances set forth in such clause (D).

        The Company shall purchase from the Holder thereof, pursuant to this
Section 3.08, a portion of a Security if the Principal Amount of such portion is
$1,000 or any integral multiple of $1,000. Provisions of this Indenture that
apply to the purchase of all of a Security also apply to the purchase of such
portion of such Security.

        Any purchase by the Company contemplated pursuant to the provisions of
this Section 3.08 shall be consummated by the delivery of the consideration to
be received by the Holder (together with accrued and unpaid contingent interest,
if any) promptly following the later of the Purchase Date and the time of
delivery of the Security.

        Notwithstanding anything herein to the contrary, any Holder delivering
to the Paying Agent the Purchase Notice contemplated by this Section 3.08(a)
shall have the right to withdraw such Purchase Notice at any time prior to the
close of business on the Purchase Date by delivery of a written notice of
withdrawal to the Paying Agent in accordance with Section 3.10.

        The Paying Agent shall promptly notify the Company of the receipt by it
of any Purchase Notice or written notice of withdrawal thereof.

            (c) Company's Right to Elect Manner of Payment of Purchase Price.
The Securities to be purchased pursuant to Section 3.08(a) may be paid for, at
the election of the Company, in U.S. legal tender ("cash") or Common Stock, or
in any combination of cash and Common Stock, subject to the conditions set forth
in Sections 3.08(c) and (d); provided, however, that the Purchase Price on July
26, 2002 shall be payable solely in cash. For any repurchase pursuant to this
Section 3.08 on any Purchase Date other than July 26, 2002, the Company shall
designate, in the Company Notice delivered pursuant to Section 3.08(e), whether
the Company will purchase the Securities for cash or Common Stock, or, if a
combination thereof, the percentages of the Purchase Price of Securities in
respect of which it will pay in cash or Common Stock; provided that the Company
will pay cash for fractional interests in Common Stock. For purposes of
determining the existence of potential fractional interests, all Securities
subject to purchase by the Company held by a Holder shall be considered together
(no matter how many separate certificates are to be presented). Each Holder
whose Securities are purchased pursuant to this Section 3.08 shall receive the
same percentage of cash or Common Stock in payment of the Purchase Price for
such Securities, except (i) as provided in Section 3.08(d) with regard to the
payment of cash in lieu of fractional shares of Common Stock and (ii) in the
event that the Company is unable to purchase the Securities of a Holder or
Holders for Common Stock because any of the conditions specified in Section
3.08(d) have not been satisfied, the Company may purchase the Securities of such
Holder or Holders for cash. The Company may not change its election with respect
to the consideration (or components or percentages of components thereof) to be
paid once the Company has given its Company Notice to Securityholders except
pursuant to Section 3.08(d) in the event of a failure to satisfy, prior to the
close of business on the Purchase Date, any condition to the payment of the
Purchase Price, in whole or in part, in Common Stock.

        At least three Business Days before the Company Notice Date, the Company
shall deliver an Officers' Certificate to the Trustee specifying:

            (i) the manner of payment selected by the Company,


                                       17
<PAGE>   24


            (ii) the information required by Section 3.08(e),

            (iii) if the Company elects to pay the Purchase Price, or a
            specified percentage thereof, in Common Stock, that the conditions
            to such manner of payment set forth in Section 3.08(d) have been or
            will be complied with, and

            (iv) whether the Company desires the Trustee to give the Company
            Notice required by Section 3.08(e).

            (d) Purchase with Cash. On each Purchase Date, at the option of the
Company, the Purchase Price of Securities in respect of which a Purchase Notice
pursuant to Section 3.08(a) has been given, or a specified percentage thereof,
may be paid by the Company with cash equal to the aggregate Purchase Price of
such Securities. On July 26, 2002, the Purchase Price of Securities for which a
Purchase Notice pursuant to Section 3.08(a) has been given, or a specified
percentage thereof, may be paid by the Company only in cash equal to the
Purchase Price of such Securities.

            (e) Payment by Issuance of Common Stock. On each Purchase Date other
than July 26, 2002, at the option of the Company, the Purchase Price of
Securities in respect of which a Purchase Notice pursuant to Section 3.08(a) has
been given, or a specified percentage thereof, may be paid by the Company by the
issuance of a number of shares of Common Stock equal to the quotient obtained by
dividing (i) the amount of cash to which the Securityholders would have been
entitled had the Company elected to pay all or such specified percentage, as the
case may be, of the Purchase Price of such Securities in cash by (ii) the Market
Price of a share of Common Stock, subject to the next succeeding paragraph.

        The Company will not issue a fractional share of Common Stock in payment
of the Purchase Price. Instead the Company will pay cash for the current market
value of the fractional share. The current market value of a fraction of a share
shall be determined by multiplying the Market Price by such fraction and
rounding the product to the nearest whole cent. It is understood that if a
Holder elects to have more than one Security purchased, the number of shares of
Common Stock shall be based on the aggregate amount of Securities to be
purchased.

        Upon a payment by Common Stock pursuant to the terms hereof, that
portion of accrued Tax Original Issue Discount attributable to the period from
the Issue Date to the Purchase Date with respect to the purchased Security shall
not be cancelled, extinguished or forfeited but rather shall be deemed paid in
full to the Holder through the delivery of the Common Stock in exchange for the
Security being purchased pursuant to the terms hereof, and the fair market value
of such Common Stock (together with any cash payments in lieu of fractional
shares of Common Stock) shall be treated as issued, to the extent thereof, first
in exchange for the Tax Original Issue Discount accrued through the Purchase
Date, and the balance, if any, of the fair market value of such shares of Common
Stock shall be treated as issued in exchange for the Issue Price of the Security
being purchased pursuant to the provisions hereof.

        The Company's right to exercise its election to purchase the Securities
pursuant to Section 3.08 through the issuance of shares of Common Stock shall be
conditioned upon:

            (i) the Company's not having given its Company Notice of an election
            to pay entirely in cash and its giving of timely Company Notice of
            election to purchase all or a specified percentage of the Securities
            with Common Stock as provided herein;

            (ii) the shares of Common Stock having been admitted for listing or
            admitted for listing subject to notice of issuance on the principal
            United States securities exchange on which the Common Stock is then
            listed or, if the Common Stock is not then listed on a national or
            regional securities exchange, as quoted on the National Association
            of Securities Dealers Automated Quotation System;


                                       18
<PAGE>   25

            (iii) the registration of the shares of Common Stock to be issued in
            respect of the payment of the Purchase Price under the Securities
            Act of 1933, as amended (the "Securities Act"), or the Securities
            Exchange Act of 1934, as amended (the "Exchange Act"), in each case,
            if required;

            (iv) any necessary qualification or registration under applicable
            state securities laws or the availability of an exemption from such
            qualification and registration; and

            (v) the receipt by the Trustee of an Officers' Certificate and an
            Opinion of Counsel each stating that (A) the terms of the issuance
            of the Common Stock are in conformity with this Indenture and (B)
            the shares of Common Stock to be issued by the Company in payment of
            the Purchase Price in respect of Securities have been duly
            authorized and, when issued and delivered pursuant to the terms of
            this Indenture in payment of the Purchase Price in respect of the
            Securities, will be validly issued, fully paid and non-assessable
            and, to the best of such counsel's knowledge, free from preemptive
            rights, and, in the case of such Officers' Certificate, stating that
            conditions (i), (ii), (iii) and (iv) above and the condition set
            forth in the second succeeding sentence have been satisfied and, in
            the case of such Opinion of Counsel, stating that conditions (ii),
            (iii) and (iv) above have been satisfied.

        Such Officers' Certificate shall also set forth the number of shares of
Common Stock to be issued for each $1,000 Principal Amount of Securities and the
Sale Price of a share of Common Stock on each trading day during the period for
which the Market Price is calculated. The Company may pay the Purchase Price (or
any portion thereof) in Common Stock only if the information necessary to
calculate the Market Price is published in a daily newspaper of national
circulation or by other appropriate means. If the foregoing conditions are not
satisfied with respect to a Holder or Holders prior to the close of business on
the Purchase Date and the Company has elected to purchase the Securities
pursuant to this Section 3.08 through the issuance of shares of Common Stock,
the Company shall pay the entire Purchase Price of the Securities of such Holder
or Holders in cash.

        The "Market Price" of the Common Stock means the average of the Sale
Prices of the Common Stock for the five trading day period ending on (if the
third Business Day prior to the applicable Purchase Date is a trading day or, if
not, then on the last trading day prior to) the third Business Day prior to the
applicable Purchase Date, appropriately adjusted to take into account the
occurrence, during the period commencing on the first of such trading days
during such five trading day period and ending on such Purchase Date, of any
event described in Section 11.06, 11.07 or 11.08; subject, however, to the
conditions set forth in Sections 11.09 and 11.10.

            (f) Notice of Election. The Company's notice of election to purchase
with cash or Common Stock or any combination thereof (the "Company Notice")
shall be sent to the Holders (and to beneficial owners as required by applicable
law) in the manner provided in Section 13.02 not less than 20 Business Days
prior to the applicable Purchase Date or 15 Business Days prior to the
applicable Change in Control Purchase Date (the "Company Notice Date"). Any such
Company Notice shall state the manner of payment elected and shall contain the
following information:

        In the event the Company has elected to pay the Purchase Price (or a
specified percentage thereof) with Common Stock, the Company Notice shall:

               (1) state that each Holder will receive Common Stock with a
        Market Price determined as of a specified date prior to the Purchase
        Date equal to such specified percentage of the Purchase Price of the
        Securities held by such Holder (except any cash amount to be paid in
        lieu of fractional shares);

               (2) set forth the method of calculating the Market Price of the
        Common Stock; and

               (3) state that because the Market Price of Common Stock will be
        determined prior to the Purchase Date, Holders will bear the market risk
        with respect to the value of the Common Stock to be received from the
        date such Market Price is determined to the Purchase Date.


                                       19
<PAGE>   26


        In any case, each Company Notice shall include a form of Purchase Notice
to be completed by a Securityholder and shall state:

            (i) the Purchase Price and the Conversion Rate and, to the extent
            known at the time of such notice, the amount of contingent interest,
            if any, that will have accrued and be payable with respect to the
            Securities as of the Purchase Date;

            (ii) the name and address of the Paying Agent and the Conversion
            Agent;

            (iii) that Securities as to which a Purchase Notice has been given
            may be converted pursuant to Article 11 hereof only if the
            applicable Purchase Notice has been withdrawn in accordance with the
            terms of this Indenture;

            (iv) that Securities must be surrendered to the Paying Agent to
            collect payment of the Purchase Price and contingent interest, if
            any;

            (v) that the Purchase Price for any Security as to which a Purchase
            Notice has been given and not withdrawn, together with any accrued
            contingent interest payable with respect thereto, will be paid
            promptly following the later of the Purchase Date and the time of
            surrender of such Security as described in (iv);

            (vi) the procedures the Holder must follow to exercise rights under
            Section 3.08 and a brief description of those rights;

            (vii) briefly, the conversion rights of the Securities;

            (viii) the procedures for withdrawing a Purchase Notice (including,
            without limitation, for a conditional withdrawal pursuant to the
            terms of Section 3.08(a)(1)(D) or Section 3.10);

            (ix) that, unless the Company defaults in making payment of such
            Purchase Price, contingent interest, if any, on Securities
            surrendered for purchase will cease to accrue on and after the
            Purchase Date; and

            (x) the CUSIP number of the Securities.

        At the Company's request, the Trustee shall give such Company Notice in
the Company's name and at the Company's expense, provided that the Company makes
such request at least 15 days (unless a shorter period shall be acceptable to
the Trustee) prior to the date such Company Notice must be mailed; and provided,
further, that, in all cases, the text of such Company Notice shall be prepared
by the Company.

        Upon determination of the actual number of shares of Common Stock to be
issued for each $1,000 Principal Amount of Securities, the Company will publish
such determination on the Company's web site or by other appropriate means.

            (g) Covenants of the Company. All shares of Common Stock delivered
upon purchase of the Securities shall be newly issued shares or treasury shares,
shall be duly authorized, validly issued, fully paid and nonassessable and shall
be free from preemptive rights and free of any lien or adverse claim.

            (h) Procedure upon Purchase. The Company shall deposit cash (in
respect of a cash purchase under Section 3.08(c) or for fractional interests or
contingent interest, as applicable) or shares of Common Stock, or a combination
thereof, as applicable, at the time and in the manner as provided in Section
3.11, sufficient to pay the aggregate Purchase Price of, and any accrued and
unpaid contingent interest with respect to, all Securities to be purchased
pursuant to this Section 3.08. As soon as practicable after the Purchase Date,
the Company shall deliver to each Holder entitled to receive Common Stock
through the Paying Agent, a certificate (or other evidence of ownership) for the
number of full shares of Common Stock issuable in payment of the Purchase Price
and cash in


                                       20
<PAGE>   27

lieu of any fractional interests. The person in whose name the certificate for
Common Stock is registered shall be treated as a holder of record of shares of
Common Stock on the Business Day following the Purchase Date. No payment or
adjustment will be made for dividends on the Common Stock the record date for
which occurred on or prior to the Purchase Date.

            (i) Taxes. If a Holder of a Security is paid in Common Stock, the
Company shall pay any documentary, stamp or similar issue or transfer tax due on
such issue of shares of Common Stock. However, the Holder shall pay any such tax
which is due if the Holder requests the shares of Common Stock to be issued in a
name other than the Holder's name. The Paying Agent may refuse to deliver the
certificates representing the Common Stock being issued in a name other than the
Holder's name until the Paying Agent receives a sum sufficient to pay any tax
which will be due because the shares of Common Stock are to be issued in a name
other than the Holder's name. Nothing herein shall preclude any income tax
withholding required by law or regulations being deducted by the Company.

        SECTION 3.09 Purchase of Securities at Option of the Holder upon a
Change in Control.

            (a) If on or prior to July 26, 2006 there shall have occurred a
Change in Control, Securities shall be purchased by the Company, at the option
of the Holder thereof, at a purchase price specified in paragraph 7 of the
Securities (the "Change in Control Purchase Price"), as of the date that is no
later than 35 Business Days after the occurrence of the applicable Change in
Control (the "Change in Control Purchase Date"), subject to satisfaction by or
on behalf of the Holder of the requirements set forth in Section 3.09(c).

        A "Change in Control" shall be deemed to have occurred at such time as
either of the following events shall occur:

            (i) There is a report filed on Schedule 13D or Schedule TO (or any
            successor schedule, form or report) pursuant to the Exchange Act,
            disclosing that any person, including the Company's Affiliates or
            Associates (for the purposes of this Section 3.09 only, as the term
            "person" is used in Section 13(d)(3) or Section 14(d)(2) of the
            Exchange Act) or group has become the beneficial owner of 50% or
            more, in the aggregate, of the voting power of the (x) voting Common
            Stock of the Company then outstanding or (y) other Capital Stock
            into which the Common Stock is reclassified or changed, or has the
            power, directly or indirectly, to elect managers, trustees, or a
            majority of the members of the Company's Board of Directors;
            provided, however, that a person shall not be deemed beneficial
            owner of, or to own beneficially, (A) any securities tendered
            pursuant to a tender or exchange offer made by or on behalf of such
            person or any of such person's Affiliates or Associates until such
            tendered securities are accepted for purchase or exchange
            thereunder, or (B) any securities if such beneficial ownership (1)
            arises solely as a result of a revocable proxy delivered in response
            to a proxy or consent solicitation made pursuant to the applicable
            rules and regulations under the Exchange Act or an exemption
            therefrom, and (2) is not also then reportable on Schedule 13D (or
            any successor schedule) under the Exchange Act; and provided,
            further, that notwithstanding the foregoing provisions of this
            Section 3.09(a)(i) only, a Change in Control shall not be deemed to
            have occurred by virtue of the Company, any Subsidiary, any employee
            stock ownership plan or any other employee benefit plan of the
            Company or any Subsidiary, or any person holding its respective
            voting common stock for or pursuant to the terms of any such
            employee benefit plan, filing or becoming obligated to file a report
            under or in response to Schedule 13D or Schedule TO (or any
            successor schedule, form or report) under the Exchange Act
            disclosing beneficial ownership by it of shares of such Capital
            Stock;

            (ii) There shall be consummated any share exchange, consolidation or
            merger of the Company pursuant to which its voting Common Stock
            would be converted into cash, securities or other property, or the
            Company sells, assigns, conveys, transfers, leases or otherwise
            disposes of all or substantially all of its assets, in each case
            other than pursuant to a share exchange, consolidation or merger of
            the Company in which the holders of such voting Capital Stock
            immediately prior to the share exchange, consolidation or merger
            have, directly or indirectly, at


                                       21
<PAGE>   28

            least a majority of the total voting power in the aggregate of all
            classes of Capital Stock of the continuing or surviving corporation
            immediately after the share exchange, consolidation or merger.

            (iii) The Company is dissolved or liquidated.

            Notwithstanding the foregoing, a Change in Control will not be
            deemed to have occurred if either: (i) the last sale price of the
            Common Stock for any five trading days during the ten trading days
            immediately preceding the Change in Control is equal to 105% or more
            of the Conversion Price in effect on such day; or

            (ii) in the case of a merger or consolidation that would otherwise
            constitute a Change in Control, all of the consideration (excluding
            cash payments for fractional shares) in the merger or consolidation
            consists of common stock traded on a United States national
            securities exchange or quoted on the National Association of
            Securities Dealers Automated Quotation System (or which will be so
            traded or quoted when issued or exchanged in connection with such
            transaction) and as a result of such transaction or transactions the
            Securities become convertible solely into such common stock.

        "Associate" shall have the meaning ascribed to such term in Rule 12b-2
of the General Rules and Regulations under the Exchange Act, as in effect on the
date hereof.

        The term "group" means any group acting for the purpose of acquiring,
holding or disposing of securities within the meaning of Rule 13d-5(b)(1) under
the Exchange Act or any successor provision.

        The term "beneficial owner" is determined in accordance with Rule 13d-3
and 13d-5 under the Exchange Act or any successor provision, except that a
person will be deemed to have beneficial ownership of all shares that such
person has the right to acquire irrespective of whether that right is
exercisable immediately or only after the passage of time.

            (b) Within 15 Business Days after the occurrence of a Change in
Control, the Company shall mail a written notice of such Change in Control by
first-class mail to the Trustee and to each Holder (and to beneficial owners as
required by applicable law). The notice shall include a form of Change in
Control Purchase Notice to be completed by the Securityholder and shall state:

            (1) briefly, the events causing a Change in Control and the date of
            such Change in Control;

            (2) the date by which the Change in Control Purchase Notice pursuant
            to this Section 3.09 must be given;

            (3) the Change in Control Purchase Price and, to the extent known at
            the time of such notice, the amount of contingent interest, if any,
            that will be accrued and payable with respect to the Securities as
            of the Change in Control Purchase Date;

            (4) the Change in Control Purchase Date;

            (5) the name and address of the Paying Agent and the Conversion
            Agent;

            (6) the Conversion Rate and any adjustments thereto;

            (7) that Securities as to which a Change in Control Purchase Notice
            has been given by the Holder may be converted pursuant to Article 11
            hereof only if the Change in Control Purchase Notice has been
            withdrawn in accordance with the terms of this Indenture;


                                       22
<PAGE>   29

            (8) that Securities must be surrendered to the Paying Agent to
            collect payment of the Change in Control Purchase Price and
            contingent interest, if any;

            (9) that the Change in Control Purchase Price for any Security as to
            which a Change in Control Purchase Notice has been duly given and
            not withdrawn, together with any accrued contingent interest payable
            with respect thereto, will be paid promptly following the later of
            the Change in Control Purchase Date and the time of surrender of
            such Security as described in (8);

            (10) briefly, the procedures the Holder must follow to exercise
            rights under this Section 3.09;

            (11) briefly, the conversion rights of the Securities and the last
            date upon which the Holder can exercise the conversion rights;

            (12) the procedures for withdrawing a Change in Control Purchase
            Notice;

            (13) that, unless the Company defaults in making payment of such
            Change in Control Purchase Price and contingent interest, if any, on
            Securities surrendered for purchase will cease to accrue on and
            after the Change in Control Purchase Date; and

            (14) the CUSIP number of the Securities.

            (c) A Holder may exercise its rights specified in Section 3.09(a)
upon delivery of a written notice of purchase (a "Change in Control Purchase
Notice") to the Paying Agent at any time prior to the close of business on the
Business Day immediately preceding the Change in Control Purchase Date, stating:

            (1) the certificate number and CUSIP number of the Security which
            the Holder will deliver to be purchased;

            (2) the portion of the Principal Amount of the Security which the
            Holder will deliver to be purchased, which portion must be $1,000 or
            an integral multiple thereof; and

            (3) that such Security shall be purchased pursuant to the terms and
            conditions specified in paragraph 7 of the Securities and this
            Section 3.09.

        The delivery of such Security to the Paying Agent prior to, on or after
the Change in Control Purchase Date (together with all necessary endorsements)
at the offices of the Paying Agent shall be a condition to the receipt by the
Holder of the Change in Control Purchase Price therefor; provided, however, that
such Change in Control Purchase Price shall be so paid pursuant to this Section
3.09 only if the Security so delivered to the Paying Agent shall conform in all
respects to the description thereof set forth in the related Change in Control
Purchase Notice and such Change in Control Purchase Notice shall not be validly
withdrawn by the Holder.

        The Company shall purchase from the Holder thereof, pursuant to this
Section 3.09, a portion of a Security if the Principal Amount of such portion is
$1,000 or an integral multiple of $1,000. Provisions of this Indenture that
apply to the purchase of all of a Security also apply to the purchase of such
portion of such Security.

        Any purchase by the Company contemplated pursuant to the provisions of
this Section 3.09 shall be consummated by the delivery of the consideration to
be received by the Holder (together with accrued and unpaid contingent interest,
if any) promptly following the later of the Change in Control Purchase Date and
the time of delivery of the Security to the Paying Agent in accordance with this
Section 3.09.

        Notwithstanding anything herein to the contrary, any Holder delivering
to the Paying Agent the Change in Control Purchase Notice contemplated by this
Section 3.09(c) shall have the right to withdraw such Change in


                                       23
<PAGE>   30

Control Purchase Notice at any time prior to the close of business on the Change
in Control Purchase Date by delivery of a written notice of withdrawal to the
Paying Agent in accordance with Section 3.10.

        The Paying Agent shall promptly notify the Company of the receipt by it
of any Change in Control Purchase Notice or written withdrawal thereof.

        The Company shall not be required to comply with this Section 3.09 if a
third party mails a written notice of Change in Control in the manner, at the
times and otherwise in compliance with this Section 3.09 and repurchases all
Securities for which a Change in Control Purchase Notice shall be delivered and
not withdrawn.

        SECTION 3.10 Effect of Purchase Notice or Change in Control Purchase
Notice. Upon receipt by the Paying Agent of the Purchase Notice or Change in
Control Purchase Notice specified in Section 3.08(a) or Section 3.09(c), as
applicable, the Holder of the Security in respect of which such Purchase Notice
or Change in Control Purchase Notice, as the case may be, was given shall
(unless such Purchase Notice or Change in Control Purchase Notice is withdrawn
as specified in the following two paragraphs) thereafter be entitled to receive
solely the Purchase Price or Change in Control Purchase Price, as the case may
be, and any accrued and unpaid contingent interest, with respect to such
Security to the Purchase Date or Change in Control Purchase Date, as the case
may be. Such Purchase Price or Change in Control Purchase Price and contingent
interest, if any, shall be paid to such Holder, subject to receipts of funds
and/or securities by the Paying Agent, promptly following the later of (x) the
Purchase Date or the Change in Control Purchase Date, as the case may be, with
respect to such Security (provided the conditions in Section 3.08(a) or Section
3.09(c), as applicable, have been satisfied) and (y) the time of delivery of
such Security to the Paying Agent by the Holder thereof in the manner required
by Section 3.08(a) or Section 3.09(c), as applicable. Securities in respect of
which a Purchase Notice or Change in Control Purchase Notice, as the case may
be, has been given by the Holder thereof may not be converted pursuant to
Article 11 hereof on or after the date of the delivery of such Purchase Notice
or Change in Control Purchase Notice, as the case may be, unless such Purchase
Notice or Change in Control Purchase Notice, as the case may be, has first been
validly withdrawn as specified in the following two paragraphs.

        A Purchase Notice or Change in Control Purchase Notice, as the case may
be, may be withdrawn by means of a written notice of withdrawal delivered to the
office of the Paying Agent in accordance with the Purchase Notice or Change in
Control Purchase Notice, as the case may be, at any time prior to the close of
business on the Purchase Date or the Change in Control Purchase Date, as the
case may be, specifying:

            (1) the Principal Amount of the Security with respect to which such
            notice of withdrawal is being submitted,

            (2) the certificate number and CUSIP number of the Security in
            respect of which such notice of withdrawal is being submitted, and

            (3) the Principal Amount, if any, of such Security which remains
            subject to the original Purchase Notice or Change in Control
            Purchase Notice, as the case may be, and which has been or will be
            delivered for purchase by the Company.

        A written notice of withdrawal of a Purchase Notice may be in the form
set forth in the preceding paragraph or may be in the form of (i) a conditional
withdrawal contained in a Purchase Notice pursuant to the terms of Section
3.08(a)(1)(D) or (ii) a conditional withdrawal containing the information set
forth in Section 3.08(a)(1)(D) and the preceding paragraph and contained in a
written notice of withdrawal delivered to the Paying Agent as set forth in the
preceding paragraph.

        There shall be no purchase of any Securities pursuant to Section 3.08
(other than through the issuance of Common Stock in payment of the Purchase
Price, including cash in lieu of fractional shares) or Section 3.09 if there has
occurred (prior to, on or after, as the case may be, the giving, by the Holders
of such Securities, of the required Purchase Notice or Change in Control
Purchase Notice, as the case may be) and is continuing an Event of Default
(other than a default in the payment of the Purchase Price or Change in Control
Purchase Price, as the case may be, and any accrued and unpaid contingent
interest with respect to such Securities). The Paying Agent will promptly


                                       24
<PAGE>   31

return to the respective Holders thereof any Securities (x) with respect to
which a Purchase Notice or Change in Control Purchase Notice, as the case may
be, has been withdrawn in compliance with this Indenture, or (y) held by it
during the continuance of an Event of Default (other than a default in the
payment of the Purchase Price or Change in Control Purchase Price, as the case
may be, and any accrued and unpaid contingent interest with respect to such
Securities) in which case, upon such return, the Purchase Notice or Change in
Control Purchase Notice with respect thereto shall be deemed to have been
withdrawn.

        SECTION 3.11 Deposit of Purchase Price or Change in Control Purchase
Price. Prior to 10:00 a.m. New York City time on the Business Day preceding the
Purchase Date or the Change in Control Purchase Date, as the case may be, the
Company shall deposit with the Trustee or with the Paying Agent (or, if the
Company or a Subsidiary or an Affiliate thereof is acting as the Paying Agent,
shall segregate and hold in trust as provided in Section 2.04) an amount of
money (in immediately available funds if deposited on such Business Day) or
Common Stock (in the case of the payment of the Purchase Price only), if
permitted hereunder, sufficient to pay the aggregate Purchase Price or Change in
Control Purchase Price, as the case may be, of, and any accrued and unpaid
contingent interest with respect to, all the Securities or portions thereof
which are to be purchased as of the Purchase Date or Change in Control Purchase
Date, as the case may be. After the Purchase Date or the Change in Control
Purchase Date, Tax Original Issue Discount and contingent interest, if any,
shall cease to accrue on such Security, whether or not such Security is
delivered to the Paying Agent.

        SECTION 3.12 Securities Purchased in Part. Any Security which is to be
purchased only in part shall be surrendered at the office of the Paying Agent
(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 such Holder's 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 any authorized denomination as requested by
such Holder in aggregate Principal Amount equal to, and in exchange for, the
portion of the Principal Amount of the Security so surrendered which is not
purchased.

        SECTION 3.13 Covenant to Comply With Securities Laws Upon Purchase of
Securities. In connection with any offer to purchase or purchase of Securities
under Section 3.08 or 3.09 hereof (provided that such offer or purchase
constitutes an "issuer tender offer" for purposes of Rule 13e-4 (which term, as
used herein, includes any successor provision thereto) under the Exchange Act at
the time of such offer or purchase), the Company shall (i) comply with Rule
13e-4 and Rule 14e-1 under the Exchange Act and any other then applicable tender
offer rules, (ii) file the related Schedule TO (or any successor schedule, form
or report) under the Exchange Act, and (iii) otherwise comply with all federal
and state securities laws so as to permit the rights and obligations under
Sections 3.08 and 3.09 to be exercised in the time and in the manner specified
in Sections 3.08 and 3.09.

        SECTION 3.14 Repayment to the Company. The Trustee and the Paying Agent
shall return to the Company any cash or shares of Common Stock that remain
unclaimed as provided in paragraph 15 of the Securities, together with interest
or dividends, if any, thereon (subject to the provisions of Section 7.01(f)),
held by them for the payment of the Purchase Price or Change in Control Purchase
Price, as the case may be, or contingent interest, if any; provided, however,
that to the extent that the aggregate amount of cash or shares of Common Stock
deposited by the Company pursuant to Section 3.11 exceeds the aggregate Purchase
Price or Change in Control Purchase Price, as the case may be, of, and the
accrued and unpaid contingent interest with respect to, the Securities or
portions thereof which the Company is obligated to purchase as of the Purchase
Date or Change in Control Purchase Date, as the case may be, then promptly after
the Business Day following the Purchase Date or Change in Control Purchase Date,
as the case may be, the Trustee shall return any such excess to the Company
together with interest or dividends, if any, thereon (subject to the provisions
of Section 7.01(f)).

                               ARTICLE 4 COVENANTS

        SECTION 4.01 Payment of Securities. The Company shall promptly make all
payments in respect of the Securities on the dates and in the manner provided in
the Securities or pursuant to this Indenture. Any amounts to be given to the
Trustee or Paying Agent, shall be deposited with the Trustee or Paying Agent by
10:00 a.m. New York City time by the Company. Principal Amount, Issue Price, Tax
Original Discount, Redemption


                                       25
<PAGE>   32

Price, Purchase Price, Change in Control Purchase Price and contingent interest,
if any, shall be considered paid on the applicable date due if on such date the
Trustee or the Paying Agent holds, in accordance with this Indenture, money or
securities, if permitted hereunder, sufficient to pay all such amounts then due.
The Company may deduct or withhold income or other similar taxes imposed by any
taxing authority in the United States from principal, premium, if any, or
interest payments hereunder.

        The Company shall, to the extent permitted by law, pay interest on
overdue amounts at the rate per annum of 8.62%, compounded semi-annually, which
interest shall accrue from the date such overdue amount was originally due to
the date payment of such amount, including interest thereon, has been made or
duly provided for. All such interest shall be payable on demand.

        SECTION 4.02 SEC and Other Reports. The Company shall file with the
Trustee, within 15 days after it files such annual and quarterly reports,
information, documents and other reports with the SEC, copies of its annual
report and of the information, documents and other reports (or copies of such
portions of any of the foregoing as the SEC may by rules and regulations
prescribe) which the Company is required to file with the SEC pursuant to
Section 13 or 15(d) of the Exchange Act. In the event the Company is at any time
no longer subject to the reporting requirements of Section 13 or 15(d) of the
Exchange Act, it shall provide the Trustee with copies such information,
documents or reports which may be required, in accordance with rules and
regulations prescribed by the Commission, pursuant to Section 13 of the Exchange
Act. In such event, such reports shall be provided at the times the Company
would have been required to comply with Rule 144A(d)(4) of the Securities Act.
The Company also shall comply with the other provisions of TIA Section 314(a).
Delivery of such reports, information and documents to the Trustee is for
informational purposes only and the Trustee's receipt of the same 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).

        SECTION 4.03 Compliance Certificate. The Company shall deliver to the
Trustee within 120 days after the end of each fiscal year of the Company
(beginning with the fiscal year ending on December 31, 2001) an Officers'
Certificate, one of the signers of which shall be the principal executive,
principal accounting or principal financial officer of the Company, such
Officer's Certificate stating whether or not to the best knowledge of the
signers thereof, a Default or an Event of Default has occurred and is continuing
and specifying in reasonable detail all such Defaults or Events of Default, if
any, and the nature and status thereof of which they may have knowledge.

        SECTION 4.04 Further Instruments and Acts. Upon request of the Trustee,
the Company will execute and deliver such further instruments and do such
further acts as may be reasonably necessary or proper to carry out more
effectively the purposes of this Indenture.

        SECTION 4.05 Maintenance of Office or Agency. The Company will maintain
an office or agency of the Trustee, Registrar, Paying Agent and Conversion Agent
where Securities may be presented or surrendered for payment, where Securities
may be surrendered for registration of transfer, exchange, purchase, redemption
or conversion and where notices and demands to or upon the Company in respect of
the Securities and this Indenture may be served. The office of LaSalle Bank
National Association, located at 135 South LaSalle Street, Suite 1960, Chicago,
Illinois 60603 (Attention: Corporate Trust Services Division), shall initially
be such office or agency for all of the aforesaid purposes. The Company shall
give prompt written notice to the Trustee of the location, and of any change in
the location, of any such office or agency (other than a change in the location
of the office of the Trustee). 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 address of the Trustee set forth in Section 13.02.

        The Company may also from time to time designate one or more other
offices or agencies where the Securities may be presented or surrendered for any
or all such purposes and may from time to time rescind such designations.


                                       26
<PAGE>   33


        SECTION 4.06 Delivery of Certain Information. At any time when the
Company is not subject to Section 13 or 15(d) of the Exchange Act, upon the
request of a Holder or any beneficial holder of Securities or shares of Common
Stock issued upon conversion thereof, the Company will promptly furnish or cause
to be furnished Rule 144A Information (as defined below) to such Holder or any
beneficial holder of Securities or holder of shares of Common Stock issued upon
conversion of Securities, or to a prospective purchaser of any such security
designated by any such holder, as the case may be, to the extent required to
permit compliance by such Holder or holder with Rule 144A under the Securities
Act in connection with the resale of any such security. "Rule 144A Information"
shall be such information as is specified pursuant to Rule 144A(d)(4) under the
Securities Act.

        SECTION 4.07 Calculation of Tax Original Issue Discount. The Company
shall file with the Trustee promptly after the end of each calendar year (i) a
written notice specifying the amount of Tax 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 Tax
Original Issue Discount as may then be relevant under the Internal Revenue Code
of 1986, as amended from time to time.

                         ARTICLE 5 SUCCESSOR CORPORATION

        SECTION 5.01 When Company May Merge or Transfer Assets. The Company
shall not consolidate with or merge with or into any other person or convey,
transfer or lease its properties and assets substantially as an entirety to any
person, unless:

            (a) either (1) the Company shall be the continuing corporation or
(2) the person (if other than the Company) formed by such consolidation or into
which the Company is merged or the person which acquires by conveyance, transfer
or lease the properties and assets of the Company substantially as an entirety
(i) shall be organized and validly existing under the laws of the United States
or any State thereof or the District of Columbia, and (ii) shall expressly
assume, by an indenture supplemental hereto, executed and delivered to the
Trustee, in form reasonably satisfactory to the Trustee, all of the obligations
of the Company under the Securities and this Indenture;

            (b) immediately after giving effect to such transaction, no Default
shall have occurred and be continuing; and

            (c) the Company shall have 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,
complies with this Article 5 and that all conditions precedent herein provided
for relating to such transaction have been satisfied.

        For purposes of the foregoing, the transfer (by lease, assignment, sale
or otherwise) of the properties and assets of one or more Subsidiaries (other
than to the Company or another Subsidiary), which, if such assets were owned by
the Company, would constitute all or substantially all of the properties and
assets of the Company, shall be deemed to be the transfer of all or
substantially all of the properties and assets of the Company.

        The successor person formed by such consolidation or into which the
Company is merged or the successor person 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 had been named as the Company herein; and thereafter, except in
the case of a lease and obligations the Company may have under a supplemental
indenture pursuant to Section 11.14, the Company shall be discharged from all
obligations and covenants under this Indenture and the Securities. Subject to
Section 9.06, the Company, the Trustee and the successor person shall enter into
a supplemental indenture to evidence the succession and substitution of such
successor person and such discharge and release of the Company.

                         ARTICLE 6 DEFAULTS AND REMEDIES

        SECTION 6.01 Events of Default. An "Event of Default" means any one of
the following events:



                                       27
<PAGE>   34


            (1) a default in the payment of the Principal Amount, Issue Price,
            Redemption Price, Purchase Price or Change in Control Purchase Price
            on any Security when the same becomes due and payable at its Stated
            Maturity, upon redemption, upon declaration, when due for purchase
            or otherwise (whether or not any such payment shall be prohibited by
            the terms of this Indenture);

            (2) a default in payment of any contingent interest which default
            continues for 30 days (whether or not any such payment shall be
            prohibited by the terms of Article 10 of this Indenture);

            (3) the Company fails either to deliver shares of Common Stock (or
            to pay cash in lieu of fractional shares) in accordance with the
            terms hereof when such Common Stock (or cash in lieu of fractional
            shares) is required to be delivered, upon conversion of a Security
            and such failure is not remedied for a period of 30 days;

            (4) the Company fails to comply with any of its other material
            agreements in this Indenture (other than those referred to in
            clauses (1), (2) and (3) above) and such failure (or the failure to
            obtain a waiver thereof) continues for 60 days after receipt by the
            Company of a Notice of Default;

            (5) (a) failure of the Company to make any payment by the end of any
            applicable grace period after maturity of indebtedness in an amount
            (taken together with amounts in (b) below) in excess of $10,000,000
            and continuance of such failure, or (b) the acceleration of
            indebtedness in an amount (taken together with amounts in (a) above)
            in excess of $10,000,000 because of a default with respect to such
            indebtedness without such indebtedness having been discharged or
            such acceleration having been cured, waived, rescinded or annulled,
            in the case of (a) or (b) above, for a period of 30 days after
            receipt by the Company of a Notice of Default; provided, however,
            that if any such failure or acceleration referred to in (a) or (b)
            above shall cease or be cured, waived, rescinded or annulled, or in
            the event of Senior Indebtedness represented by Participation
            Agreements, paid in full, then the Event of Default by reason
            thereof shall be deemed not to be continuing;

            (6) the Company or any Significant Subsidiary pursuant to or under
            or within the meaning of any Bankruptcy Law:

               (A) commences a voluntary case or proceeding;

               (B) consents to the entry of an order for relief against it in an
               involuntary case or proceeding or the commencement of any case
               against it;

               (C) consents to the appointment of a Custodian of it or for any
               substantial part of its property;

               (D) makes a general assignment for the benefit of its creditors;

               (E) files a petition in bankruptcy or answer or consent seeking
               reorganization or relief; or

               (F) consents to the filing of such petition or the appointment of
               or taking possession by a Custodian; or

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


                                       28
<PAGE>   35


               (A) is for relief against the Company or any Significant
               Subsidiary in an involuntary case or proceeding, or adjudicates
               the Company or any Significant Subsidiary insolvent or bankrupt;

               (B) appoints a Custodian of the Company or any Significant
               Subsidiary for any substantial part of its property; or

               (C) orders the winding up or liquidation of the Company or any
               Significant Subsidiary;

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

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

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

        "Significant Subsidiary" means a "significant subsidiary" and such term
is defined in Section 3-01 of Regulation S-X under the Securities Act:

        A Default under clause (4) or clause (5) above is not an Event of
Default until the Trustee notifies the Company or the Holders of at least 25% in
aggregate Principal Amount of the Securities at the time outstanding notify the
Company and the Trustee, of the Default and the Company does not cure such
Default (and such Default is not waived) within the time specified in clause (4)
or clause (5) above after actual receipt of such notice. Any such notice must
specify the Default, demand that it be remedied and state that such notice is a
"Notice of Default".

        The Company shall deliver to the Trustee, within five (5) days after it
becomes aware of the occurrence thereof, written notice of any event which with
the giving of notice or the lapse of time, or both, would become an Event of
Default under clause (4) or clause (5) above, its status and what action the
Company is taking or proposes to take with respect thereto.

        SECTION 6.02 Acceleration. Subject to Section 10.03, if an Event of
Default (other than an Event of Default specified in Section 6.01(6) or (7))
occurs and is continuing, the Trustee by Notice to the Company or the Holders of
at least 25% in aggregate Principal Amount of the Securities at the time
outstanding by notice to the Company and the Trustee, may declare the Issue
Price through the date of such declaration, and any accrued and unpaid
contingent interest through the date of such declaration, on all the Securities
to be immediately due and payable. Upon such a declaration, such Issue Price,
and such accrued and unpaid interest (including contingent interest), if any,
shall be due and payable immediately. Subject to Section 10.03, if an Event of
Default specified in Section 6.01(6) or (7) occurs and is continuing, the Issue
Price, and any accrued and unpaid contingent interest, on all the Securities to
the occurrence of such Event of Default shall become and be immediately due and
payable without any declaration or other act on the part of the Trustee or any
Securityholders. The Holders of a majority in aggregate Principal Amount of the
Securities at the time outstanding, by notice to the Trustee (and without notice
to any other Securityholder) may rescind an acceleration and its consequences if
the rescission would not conflict with any judgment or decree and if all
existing Events of Default have been cured or waived except nonpayment of the
Issue Price and any accrued and unpaid contingent interest that has become due
solely as a result of acceleration and if all amounts due to the Trustee under
Section 7.07 have been paid. No such rescission shall affect any subsequent
Event of Default or impair any right consequent thereto.

        SECTION 6.03 Other Remedies. If an Event of Default occurs and is
continuing, the Trustee may pursue any available remedy to collect the payment
of the Issue Price on the Securities or to enforce the performance of any
provision of the Securities or this Indenture.

        The Trustee may maintain a proceeding even if the Trustee does not
possess any of the Securities or does not produce any of the Securities in the
proceeding. A delay or omission by the Trustee or any Securityholder in


                                       29
<PAGE>   36


exercising any right or remedy accruing upon an Event of Default shall not
impair the right or remedy or constitute a waiver of, or acquiescence in, the
Event of Default. No remedy is exclusive of any other remedy. All available
remedies are cumulative to the extent permitted by law.

        SECTION 6.04 Waiver of Past Defaults. Subject to Sections 6.07 and 9.02,
the Holders of a majority in aggregate Principal Amount of the Securities at the
time outstanding, by notice to the Trustee (and without notice to any other
Securityholder), may waive an existing Default and its consequences except (1)
an Event of Default described in Section 6.01(1), (2) or (3), (2) a Default in
respect of a provision that under Section 9.02 cannot be amended without the
consent of each Securityholder affected or (3) a Default which constitutes a
failure to convert any Security in accordance with the terms of Article 11. When
a Default is waived, it is deemed cured, but no such waiver shall extend to any
subsequent or other Default or impair any consequent right. This Section 6.04
shall be in lieu of Section 316(a)1(B) of the TIA and such Section 316(a)1(B) is
hereby expressly excluded from this Indenture, as permitted by the TIA.

        SECTION 6.05 Control by Majority. The Holders of a majority in aggregate
Principal Amount of the Securities at the time outstanding may direct the time,
method and place of conducting any proceeding for any remedy available to the
Trustee or of exercising any trust or power conferred on the Trustee. However,
the Trustee may refuse to follow any direction that conflicts with law or this
Indenture or that the Trustee determines in good faith is unduly prejudicial to
the rights of other Securityholders or would involve the Trustee in personal
liability unless the Trustee is offered indemnity satisfactory to it. This
Section 6.05 shall be in lieu of Section 316(a)1(A) of the TIA and such Section
316(a)1(A) is hereby expressly excluded from this Indenture, as permitted by the
TIA.

        SECTION 6.06 Limitation on Suits. A Securityholder may not pursue any
remedy with respect to this Indenture or the Securities unless:

            (1) the Holder gives to the Trustee written notice stating that an
            Event of Default is continuing;

            (2) the Holders of at least 25% in aggregate Principal Amount of the
            Securities at the time outstanding make a written request to the
            Trustee to pursue the remedy;

            (3) such Holder or Holders offer to the Trustee security or
            indemnity satisfactory to the Trustee against any loss, liability or
            expense;

            (4) the Trustee does not comply with the request within 60 days
            after receipt of such notice, request and offer of security or
            indemnity; and

            (5) the Holders of a majority in aggregate Principal Amount of the
            Securities at the time outstanding do not give the Trustee a
            direction inconsistent with the request during such 60-day period.

        A Securityholder may not use this Indenture to prejudice the rights of
any other Securityholder or to obtain a preference or priority over any other
Securityholder.

        SECTION 6.07 Rights of Holders to Receive Payment. Notwithstanding any
other provision of this Indenture, the right of any Holder to receive payment of
the Principal Amount, Issue Price, Redemption Price, Purchase Price, Change in
Control Purchase Price or contingent interest, if any, in respect of the
Securities held by such Holder, on or after the respective due dates expressed
in the Securities or any Redemption Date, and to convert the Securities in
accordance with Article 11, or to bring suit for the enforcement of any such
payment on or after such respective dates or the right to convert, shall not be
impaired or affected adversely without the consent of such Holder.

        SECTION 6.08 Collection Suit by Trustee. If an Event of Default
described in Section 6.01(1) or (2) occurs and is continuing, the Trustee may
recover judgment in its own name and as trustee of an express trust


                                       30
<PAGE>   37


against the Company for the whole amount owing with respect to the Securities
and the amounts provided for in Section 7.07.

        SECTION 6.09 Trustee May File Proofs of Claim. In case of the pendency
of any receivership, insolvency, liquidation, bankruptcy, reorganization,
arrangement, adjustment, composition or other judicial proceeding relative to
the Company or any other obligor upon the Securities or the property of the
Company or of such other obligor or their creditors, the Trustee (irrespective
of whether the Principal Amount, Issue Price, Redemption Price, Purchase Price,
Change in Control Purchase Price or contingent interest, if any, in respect of
the Securities shall then be due and payable as therein expressed or by
declaration or otherwise and irrespective of whether the Trustee shall have made
any demand on the Company for the payment of any such amount) shall be entitled
and empowered, by intervention in such proceeding or otherwise,

            (a) to file and prove a claim for the whole amount of the Principal
            Amount, Issue Price, Redemption Price, Purchase Price, Change in
            Control Purchase Price or contingent interest, if any, 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, expenses, disbursements and advances of the
            Trustee, its agents and counsel or any other amounts due the Trustee
            under Section 7.07) and of the Holders allowed in such judicial
            proceeding, and

            (b) 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
similar official in any such judicial proceeding is hereby authorized by each
Holder to make such payments to the Trustee and, in the event that the Trustee
shall consent to the making of such payments directly to the Holders, to pay the
Trustee any amount due it for the reasonable compensation, expenses,
disbursements and advances of the Trustee, its agents and counsel, and any other
amounts due the Trustee under Section 7.07.

        Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder any plan of
reorganization, arrangement, adjustment or composition affecting the 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.

        SECTION 6.10 Priorities. If the Trustee collects any money pursuant to
this Article 6, it shall pay out the money in the following order:

            FIRST: to the Trustee for amounts due under Section 7.07;

            SECOND: to holders of Senior Indebtedness to the extent required by
            Article 10;

            THIRD: to Securityholders for amounts due and unpaid on the
            Securities for the Principal Amount, Issue Price, Redemption Price,
            Purchase Price, Change in Control Purchase Price or contingent
            interest, if any, as the case may be, ratably, without preference or
            priority of any kind, according to such amounts due and payable on
            the Securities; and

            FOURTH: the balance, if any, to the Company .

        The Trustee may fix a record date and payment date for any payment to
Securityholders pursuant to this Section 6.10. At least 15 days before such
record date, the Trustee shall mail to each Securityholder and the Company a
notice that states the record date, the payment date and the amount to be paid.

        SECTION 6.11 Undertaking for Costs. In any suit for the enforcement of
any right or remedy under this Indenture or in any suit against the Trustee for
any action taken or omitted by it as Trustee, a court in its discretion may
require the filing by any party litigant (other than the Trustee) in the suit of
an undertaking to pay the costs of the suit, and the court in its discretion may
assess reasonable costs, including reasonable attorneys' fees and


                                       31
<PAGE>   38


expenses, against any party litigant in the suit, having due regard to the
merits and good faith of the claims or defenses made by the party litigant. This
Section 6.11 does not apply to a suit by the Trustee, a suit by a Holder
pursuant to Section 6.07 or a suit by Holders of more than 10% in aggregate
Principal Amount of the Securities at the time outstanding. This Section 6.11
shall be in lieu of Section 315(e) of the TIA and such Section 315(e) is hereby
expressly excluded from this Indenture, as permitted by the TIA.

        SECTION 6.12 Waiver of Stay, Extension or Usury Laws. The Company
covenants (to the extent that it may lawfully do so) that they will not at any
time insist upon, or plead, or in any manner whatsoever claim or take the
benefit or advantage of, any stay or extension law or any usury or other law
wherever enacted, now or at any time hereafter in force, which would prohibit or
forgive the Company from paying all or any portion of the Principal Amount,
Issue Price, Redemption Price, Purchase Price, Change in Control Purchase Price,
contingent interest, if any, delivering Common Stock upon a conversion pursuant
to Article 11 or paying the cash equivalent thereof, in respect of Securities,
or any interest on such amounts, as contemplated herein, or 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 7 TRUSTEE

        SECTION 7.01 Duties of Trustee.

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

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

            (i) the Trustee need perform only those duties that are specifically
            set forth in this Indenture and no implied covenants or obligations
            shall be read into this Indenture against the Trustee; and

            (ii) in the absence of bad faith on its part, the Trustee may
            conclusively rely, as to the truth of the statements and the
            correctness of the opinions expressed therein, upon certificates or
            opinions furnished to the Trustee and conforming to the requirements
            of this Indenture, the Trustee shall examine such certificates and
            opinions to determine whether or not they conform to the
            requirements of this Indenture, but need not confirm or investigate
            the accuracy of mathematical calculations or other facts stated
            therein.

This Section 7.01(b) shall be in lieu of Section 315(a) of the TIA and such
Section 315(a) is hereby expressly excluded from this Indenture, as permitted by
the TIA.

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

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

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

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


                                       32
<PAGE>   39


Subparagraphs (c)(1), (2) and (3) shall be in lieu of Sections 315(d)(1),
315(d)(2) and 315(d)(3) of the TIA and such Sections 315(d)(1), 315(d)(2) and
315(d)(3) are hereby expressly excluded from this Indenture, as permitted by the
TIA.

            (d) Every provision of this Indenture that in any way relates to the
Trustee is subject to paragraphs (a), (b), (c) and (e) of this Section 7.01.

            (e) The Trustee may refuse to perform any duty or exercise any right
or power or expend or risk its own funds or otherwise incur any financial
liability unless it receives indemnity satisfactory to it against any loss,
liability or expense.

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

        SECTION 7.02 Rights of Trustee. Subject to its duties and
responsibilities under the provisions of Section 7.01, and, except as expressly
excluded from this Indenture pursuant to said Section 7.01, under the TIA:

            (a) the Trustee may conclusively 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, authenticated or presented
by the proper party or parties;

            (b) 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,
conclusively rely upon an Officers' Certificate;

            (c) 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;

            (d) the Trustee shall not be liable for any action taken, suffered,
or omitted to be taken by it in good faith which it believes to be authorized or
within its rights or powers conferred under this Indenture;

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

            (f) the Trustee shall be under no obligation to exercise any of the
rights or powers vested in it by this Indenture at the request, order or
direction of any of the Holders, pursuant to the provisions of this Indenture,
unless such Holders shall have offered to the Trustee security or indemnity
satisfactory to it against the costs, expenses and liabilities which may be
incurred therein or thereby;

            (g) any request or direction of the Company mentioned herein shall
be sufficiently evidenced by a Company Request or Company Order, accompanied, if
applicable, by a resolution of the Board of Directors of the Company;

            (h) 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
including, without limitation, any Company Request, Company Order, or Officer's
Certificate, but the Trustee, in its discretion, may make such


                                       33
<PAGE>   40

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 upon reasonable notice to the Company, personally or by agent or
attorney at the sole cost of the Company and shall incur no liability or
additional liability of any kind by reason of such inquiry or investigation or
the lack thereof;

            (i) 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 or 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;

            (j) 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 to each agent, custodian and other Person
employed to act hereunder;

            (k) 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 such
Officers' Certificate, including any person specified as so authorized in any
such certificate previously delivered and not superseded; and

        (l) before the Trustee acts or refrains from acting, it may request, and
shall be entitled to receive, an Officers' Certificate or an Opinion of Counsel.
The Trustee shall not be liable for any action it takes or omits to take in good
faith reliance on such Certificate or Opinion. The Trustee may also consult with
counsel on any matter relating to the Indenture or the Securities and the
Trustee shall not be liable for any action it takes or omits to take in good
faith in reliance on the advice of counsel.

        SECTION 7.03 Individual Rights of Trustee. The Trustee in its individual
or any other capacity may become the owner or pledgee of Securities and may
otherwise deal with the Company or its Affiliates with the same rights it would
have if it were not Trustee. Any Paying Agent, Registrar, Conversion Agent or
co-registrar may do the same with like rights. However, the Trustee must comply
with Sections 7.10 and 7.11.

        SECTION 7.04 Trustee's Disclaimer. The Trustee makes no representation
as to the validity or adequacy of this Indenture or the Securities, it shall not
be accountable for the Company's use or application of the proceeds from the
Securities, it shall not be responsible for any statement in the registration
statement for the Securities under the Securities Act or in the Indenture or the
Securities (other than its certificate of authentication), or the determination
as to which beneficial owners are entitled to receive any notices hereunder.

        SECTION 7.05 Notice of Defaults. If a Default occurs and if it is known
to the Trustee, the Trustee shall give to each Securityholder notice of the
Default within 90 days after it occurs unless such Default shall have been cured
or waived before the giving of such notice. Except in the case of a Default
described in Section 6.01(1), (2) or (3), the Trustee may withhold the notice if
and so long as a committee of its Responsible Officers in good faith determines
that withholding the notice is in the interests of Securityholders. The second
sentence of this Section 7.05 shall be in lieu of the proviso to Section 315(b)
of the TIA and such proviso is hereby expressly excluded from this Indenture, as
permitted by the TIA. The Trustee shall not be deemed to have knowledge of a
Default unless a Responsible Officer of the Trustee has received written notice
of such Default.

        SECTION 7.06 Reports by Trustee to Holders. Within 60 days after each
May 15 beginning with the May 15 following the date of this Indenture, the
Trustee shall mail to each Securityholder a brief report dated as of such May 15
that complies with TIA Section 313(a), if required by such Section 313(a). The
Trustee also shall comply with TIA Section 313(b).

        A copy of each report at the time of its mailing to Securityholders
shall be filed with the SEC and each securities exchange, if any, on which the
Securities are listed. The Company agrees to promptly notify the Trustee
whenever the Securities become listed on any securities exchange and of any
delisting thereof.


                                       34
<PAGE>   41


        SECTION 7.07 Compensation and Indemnity.

The Company agrees:

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

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

            (c) to indemnify the Trustee or any predecessor, Trustee and their
agents for, and to hold them harmless against, any loss, damage, claim,
liability, cost or expense (including attorney's fees and taxes (other than
taxes based upon, measured by or determined by the income of the Trustee))
incurred without negligence, willful misconduct or bad faith on its part,
arising out of or in connection with the acceptance or administration of this
trust, including the reasonable costs and expenses of defending itself against
any claim (whether asserted by the Company or any 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 promptly notify the Company of any claim asserted
against the Trustee or any of its agents for which it may seek indemnity. The
Company shall defend, through counsel reasonably satisfactory to the Trustee any
claim, cost, liabilities, damages and expenses, arising out of the Trustee's
failure to perform any of its obligations under this Indenture, provided that
the Trustee may, at the expense of the Company, assume the defense of any
action, and provided further that the Trustee shall be consulted and have the
right to approve any settlement of any claim or suit.

        To secure the Company's payment obligations in this Section 7.07, the
Trustee shall have a lien prior to the Securities on all money or property held
or collected by the Trustee, in its capacity as Trustee, except that held in
trust to pay the Principal Amount, Issue Price, Redemption Price, Purchase
Price, Change in Control Purchase Price or contingent interest, if any, as the
case may be, on particular Securities, or Common Stock delivered upon a
conversion pursuant to Article 11, or the cash equivalent thereof.

        The Company's payment obligations pursuant to this Section 7.07 shall
survive the discharge of this Indenture and the resignation or removal of the
Trustee. When the Trustee incurs expenses after the occurrence of a Default
specified in Section 6.01(6) or (7), the expenses including the reasonable
charges and expenses of its counsel, are intended to constitute expenses of
administration under any Bankruptcy Law.

        SECTION 7.08 Replacement of Trustee. The Trustee may resign by so
notifying the Company; provided, however, no such resignation shall be effective
until a successor Trustee has accepted its appointment pursuant to this Section
7.08. The Holders of a majority in aggregate Principal Amount of the Securities
at the time outstanding may remove the Trustee by so notifying the Trustee and
the Company. The Company shall remove the Trustee if:

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

            (b) the Trustee is adjudged bankrupt or insolvent;

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

            (d) the Trustee otherwise becomes incapable of acting.


                                       35
<PAGE>   42


        If the Trustee resigns or is removed or if a vacancy exists in the
office of Trustee for any reason, the Company shall promptly appoint a successor
Trustee.

        A successor Trustee shall deliver a written acceptance of its
appointment to the retiring Trustee and the Company satisfactory in form and
substance to the retiring Trustee and the Company. Thereupon the resignation or
removal of the retiring Trustee shall become effective, and the successor
Trustee shall have all the rights, powers and duties of the Trustee under this
Indenture. The successor Trustee shall mail a notice of its succession to
Securityholders. The retiring Trustee shall promptly transfer all property held
by it as Trustee to the successor Trustee, subject to the lien provided for in
Section 7.07.

        If a successor Trustee does not take office within 30 days after the
retiring Trustee resigns or is removed, the retiring Trustee, the Company or the
Holders of a majority in aggregate Principal Amount of the Securities at the
time outstanding may petition any court of competent jurisdiction at the expense
of the Company for the appointment of a successor Trustee.

        If the Trustee fails to comply with Section 7.10, any Securityholder may
petition any court of competent jurisdiction for the removal of the Trustee and
the appointment of a successor Trustee.

        The resignation or removal of a Trustee shall not diminish or impair its
rights to indemnification pursuant to Section 7.07.

        SECTION 7.09 Successor Trustee by Merger. If the Trustee consolidates
with, merges or converts into, or transfers all or substantially all its
corporate trust business or assets to, another corporation, the resulting,
surviving or transferee corporation without any further act shall, if otherwise
eligible hereunder, be the successor Trustee.

        SECTION 7.10 Eligibility; Disqualification. The Trustee shall at all
times satisfy the requirements of TIA Sections 310(a)(1) and 310(b). The Trustee
(or its parent holding company) shall have a combined capital and surplus of at
least $50,000,000 as set forth in its most recent published annual report of
condition. Nothing herein contained shall prevent the Trustee from filing with
the Commission the application referred to in the penultimate paragraph of TIA
Section 310(b).

        SECTION 7.11 Preferential Collection of Claims Against Company. The
Trustee shall comply with TIA Section 311(a), excluding any creditor
relationship listed in TIA Section 311(b). A Trustee who has resigned or been
removed shall be subject to TIA Section 311(a) to the extent indicated therein.

                        ARTICLE 8 DISCHARGE OF INDENTURE

        SECTION 8.01 Discharge of Liability on Securities. When (i) the Company
delivers to the Trustee all outstanding Securities (other than Securities
replaced pursuant to Section 2.07) for cancellation or (ii) all outstanding
Securities have become due and payable and the Company deposits with the Trustee
cash or, if expressly permitted by the terms of the Securities, Common Stock
sufficient to pay all amounts due and owing on all outstanding Securities (other
than Securities replaced pursuant to Section 2.07), and if in either case the
Company pays all other sums payable hereunder by the Company, then this
Indenture shall, subject to Section 7.07, cease to be of further effect. The
Trustee shall join in the execution of a document prepared by the Company
acknowledging satisfaction and discharge of this Indenture on demand of the
Company accompanied by an Officers' Certificate and Opinion of Counsel and at
the cost and expense of the Company.

        SECTION 8.02 Repayment to the Company. The Trustee and the Paying Agent
shall return to the Company upon written request any money or securities held by
them for the payment of any amount with respect to the Securities that remains
unclaimed for one year, subject to applicable unclaimed property law. After
return to the Company, Holders entitled to the money or securities must look to
the Company for payment as general creditors unless an applicable abandoned
property law designates another person and the Trustee and the Paying


                                       36
<PAGE>   43

Agent shall have no further liability to the Securityholders with respect to
such money or securities for that period commencing after the return thereof.

                              ARTICLE 9 AMENDMENTS

        SECTION 9.01 Without Consent of Holders. The Company and the Trustee may
amend this Indenture or the Securities without notice to or the consent of any
Securityholder:

            (1) to comply with Article 5 or Section 11.14;

            (2) to add to the Company's covenants for the benefit of the
            Securityholders or to surrender any right or power conferred upon
            the Company ;

            (3) to secure the Company's obligations under the Securities and
            this Indenture;

            (4) to make any change to comply with the TIA, or any amendment
            thereto, or to comply with any requirement of the SEC in connection
            with the qualification of the Indenture under the TIA, or as
            necessary in connection with the registration of the Securities
            under the Securities Act; or

            (5) to cure any ambiguity, omission, defect or inconsistency;

            (6) to make any change that does not adversely affect the rights of
            any Holders hereunder.

        Notwithstanding the above, clauses (2), (3), (4) and (5) above may not
be modified or amended without the consent of the Holders of a majority in
aggregate Principal Amount of the Securities then outstanding, if such
modification or amendment materially and adversely affects the interests of the
Holders of the Securities.

        SECTION 9.02 With Consent of Holders. Subject to Section 6.07, with the
written consent of the Holders of at least a majority in aggregate Principal
Amount of the Securities at the time outstanding, the Company and the Trustee
may amend this Indenture or the Securities. However, without the consent of each
Securityholder affected, an amendment to this Indenture or the Securities may
not:

            (1) make any change in the Stated Maturity, make any change in the
            manner of calculation of, or that adversely affects the right to
            receive, contingent interest, reduce the rate of interest referred
            to in paragraph 1 of the Securities or extend the time for payment
            of contingent interest, if any, on any Security;

            (2) make any Security payable in money or securities other than as
            stated in the Security;

            (3) extend the Stated Maturity of any Security

            (4) reduce the Principal Amount or the Issue Price of any Security;

            (5) reduce the Redemption Price, Purchase Price or Change in Control
            Purchase Price of any Security;

            (6) make any change that adversely affects the right to convert any
            Security;

            (7) make any change that adversely affects the right to require the
            Company to purchase the Securities in accordance with the terms
            thereof and this Indenture; or

                                       37
<PAGE>   44



            (8) modify the provisions of this Indenture relating to the
            subordination of the Securities in a manner adverse to the Holders
            of the Securities;

            (9) impair the right to institute suit for the enforcement of any
            payment with respect to, or conversion of, the Securities.

            (10) make any change in Section 6.04 or this Section 9.02, except to
            increase any percentage set forth therein;

            (11) change the provisions of this Indenture that relate to
            modifying or amending this Indenture;

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

        After an amendment, supplement or waiver under this Section 9.02 becomes
effective, the Company shall mail to each Holder a notice briefly describing the
amendment, supplement or waiver.

        An amendment, supplement or waiver under this Section 9.02 or Section
9.01 may not make any change that adversely affects the rights under Article 10
of any holder of Senior Indebtedness then outstanding unless the requisite
holders of such Senior Indebtedness consent to such change pursuant to the terms
of such Senior Indebtedness.

        SECTION 9.03 Compliance with Trust Indenture Act. Every supplemental
indenture executed pursuant to this Article shall comply with the TIA.

        SECTION 9.04 Revocation and Effect of Consents, Waivers and Actions.
Until an amendment, waiver or other action by Holders becomes effective, a
consent thereto by a Holder of a Security hereunder is a continuing consent by
the Holder and every subsequent Holder of that Security or portion of the
Security that evidences the same obligation as the consenting Holder's Security,
even if notation of the consent, waiver or action is not made on the Security.
However, any such Holder or subsequent Holder may revoke the consent, waiver or
action as to such Holder's Security or portion of the Security if the Trustee
receives the notice of revocation before the date the amendment, waiver or
action becomes effective. After an amendment, waiver or action becomes
effective, it shall bind every Securityholder.

        SECTION 9.05 Notation on or Exchange of Securities. Securities
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 so
modified as to conform, in the opinion of the Board of Directors of 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.

        SECTION 9.06 Trustee to Sign Supplemental Indentures. The Trustee shall
sign any supplemental indenture authorized pursuant to this Article 9 if the
amendment contained therein does not adversely affect the rights, duties,
liabilities or immunities of the Trustee. If it does, the Trustee may, but need
not, sign such supplemental indenture. In signing such supplemental indenture
the Trustee shall receive, and (subject to the provisions of Section 7.01) shall
be fully protected in relying upon, an Officers' Certificate and an Opinion of
Counsel stating that such amendment is authorized or permitted by this
Indenture.

        SECTION 9.07 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.


                                       38
<PAGE>   45


                            ARTICLE 10 SUBORDINATION

        SECTION 10.01 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 all Securities shall be issued subject to
the provisions of this Article 10 and to the extent and in the manner
hereinafter set forth in this Article 10, the indebtedness represented by the
Securities and the payment of the Principal Amount, Issue Price, Redemption
Price, cash in respect of Purchase Price, Change in Control Purchase Price, and
contingent interest, if any, in respect of each and all of the Securities are
hereby expressly made subordinate and junior and subject in right of payment to
the prior payment in full of all Senior Indebtedness whether outstanding on the
date hereof or thereafter incurred.

        SECTION 10.02 Payment Over of Proceeds Upon Dissolution, Etc. Subject to
the rights of the Holders of the Securities pursuant to the Pledge Agreement,
upon any distribution of assets of the Company 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 (1) 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 (other than
Permitted Junior Securities) on account of the Principal Amount, Issue Price,
Redemption Price, cash in respect of the Purchase Price, Change in Control
Purchase Price or contingent interest, if any, in respect of the Securities, and
(2) any payment or distribution of any kind or character, whether in cash,
property or securities (other than Permitted Junior 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, 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, until, in each case, such Senior Indebtedness is paid
in full or payment thereof is duly provided for. 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
(other than Permitted Junior Securities and except, in each case, for payments
made from funds then held pursuant to the Pledge Agreement for the benefit of
Holders of the 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 in such
event such payment or distribution shall be paid over or delivered forthwith by
the person holding such funds 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. 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 5 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 part of such consolidation, merger, conveyance or transfer,
comply with the conditions set forth in Article 5.

        SECTION 10.03 Acceleration of Securities. In the event that any
Securities are declared due and payable before their Stated Maturity pursuant to
Section 6.02, then and in such event the Company shall promptly notify holders
of Senior Indebtedness of such acceleration. The Company may not pay the
Securities (except, in each case, for payments made from funds then held
pursuant to the Pledge Agreement for the benefit of Holders of the Securities)
until the earlier of (i) the passage of 120 or more days have passed after such
acceleration occurs or (ii) the payment in full of all Senior Indebtedness, and
may thereafter pay the Securities if this Article 10 permits the


                                       39
<PAGE>   46


payment at that time. In the event that, notwithstanding the foregoing, the
Company shall make any payment to the Trustee or the Holder of any Securities
prohibited by the foregoing provisions of this Section 10.03, and if such facts
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 by or on behalf of the
person holding such payment for the benefit of the holders of Senior
Indebtedness. The provisions of this Section 10.03 shall not apply to any
payment with respect to which Section 10.02 would be applicable.

        SECTION 10.04 Default on Senior Indebtedness. The Company may not make
any payment of the Principal Amount, Issue Price, Redemption Price, Change in
Control Purchase Price, or contingent interest, if any, in respect of the
Securities nor may the Company pay cash with respect to the Purchase Price or
Change in Control Purchase Price or acquire any Securities for cash or property
(except, in each case, for payments made from funds then held pursuant to the
Pledge Agreement for the benefit of Holders of the Securities, and except as
otherwise provided by Article 11 and other than for Common Stock of the Company)
if: (1) a payment default on any Senior Indebtedness has occurred and is
continuing beyond any applicable grace period with respect thereto; or (2) a
default (other than a default referred to in the preceding clause (1)) on any
Senior Indebtedness occurs and is continuing that permits holders of such Senior
Indebtedness to accelerate the maturity thereof and the default is the subject
of judicial proceedings or the Company receives a notice of default thereof from
any person who may give such notice pursuant to the instrument evidencing or
document governing such Senior Indebtedness. If the Company receives any such
notice, then a similar notice received within nine months thereafter relating to
the same default on the same issue of Senior Indebtedness shall not be effective
for purposes of this Section 10.04. The Company may resume payment on the
Securities and may acquire Securities if and when: (A) the default referred to
above is cured or waived; or (B) in the case of a default referred to in clause
(2) of the preceding paragraph, 179 or more days pass after the receipt by the
Company of the notice described in clause (2) above; and this Article 10
otherwise permits the payment or acquisition at that time. 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 then have been made known to the Trustee or, as
the case may be, such Holder, then and in such event such payment (except for a
payment made from funds then held pursuant to the Pledge Agreement for the
benefit of Holders of the Securities) shall (to the extent permitted by law) be
paid over and delivered forthwith to the Company by or on behalf of the person
holding such payment for the benefit of the holders of the Senior Indebtedness.
Nothing contained in this Article 10 or elsewhere in this Indenture or in any of
the Securities shall prevent the conversion by a Holder of any Securities into
Common Stock in accordance with the provisions for conversion of such Securities
set forth in this Indenture, including the payment of cash in lieu of fractional
shares of Common Stock in accordance with Article 11 in the event of an
occurrence of the events described in this Section 10.04. The provisions of this
Section shall not apply to any payment with respect to which Section 10.02 would
be applicable.

        SECTION 10.05 Payment Permitted If No Default. 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 10.02 or under the conditions described in Section 10.03 or 10.04,
from making payments at any time of Principal Amount, Issue Price, Redemption
Price, Purchase Price, Change in Control Purchase Price or contingent interest,
if any, as the case may be, in respect of 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 Amount, Issue Price, Redemption Price, Purchase Price,
Change in Control Purchase Price or contingent interest, if any, as the case may
be, in respect of the Securities or the retention of such payment by the Holders
of the Securities, if, at the time of such application by the Trustee, the
Trustee did not have actual knowledge subject to the provisions of Section 10.10
that such payment would have been prohibited by the provisions of this Article.

        SECTION 10.06 Subrogation to Rights of Holders of Senior Indebtedness.
Subject to payment in full of all Senior Indebtedness (and except for payments
made from funds then held pursuant to the Pledge Agreement for the benefit of
Holders of the Securities), 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 (equally and ratably
with the holders of all indebtedness of the Company which by its express terms
is subordinated to indebtedness of the Company to substantially the same extent
as the Securities are subordinated and


                                       40
<PAGE>   47

is entitled to like rights of subrogation) to the rights of the holders of such
Senior Indebtedness to receive payments or distributions of cash, property and
securities applicable to the Senior Indebtedness until the Principal Amount,
Issue Price, Redemption Price, Purchase Price, Change in Control Purchase Price
or contingent interest, if any, if any, as the case may be, in respect of 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 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 10.07 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, 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 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, is intended to rank
equally with all other general obligations of the Company), to pay to the
Holders of the Securities the Principal Amount, Issue Price, Redemption Price,
Purchase Price, Change in Control Purchase Price or contingent interest, if any,
as the case may be, in respect of the Securities as and when the same shall
become due and payable in accordance with the terms of the Securities and this
Indenture; 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; 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 to receive cash, property and securities otherwise
payable or deliverable to the Trustee or such Holder.

        SECTION 10.08 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; provided that the Trustee shall
have no obligation to take any action, or to refrain from taking any action,
unless requested in writing by the Holders of the majority of the outstanding
Securities.

        SECTION 10.09 No Waiver of Subordination Provisions. No right of any
present or future holder of any Senior Indebtedness to enforce the subordination
as herein provided shall at any time in any way be prejudiced or impaired by any
act or failure to act on the part of the Company or by any act or failure to
act, in good faith, by any such holder, or by any 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 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, 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 otherwise amend or supplement in any manner Senior Indebtedness
or any instrument evidencing the same or any agreement under which Senior
Indebtedness is outstanding; (ii) sell, exchange, release or otherwise deal with
any property pledged, mortgaged or otherwise securing Senior Indebtedness; (iii)
release any Person liable in any manner for the collection of Senior
Indebtedness; and (iv) exercise or refrain from exercising any rights against
the Company and any other Person.

        SECTION 10.10 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; and, prior to the receipt of any such written notice,
the Trustee shall be entitled in all respects to assume that no such facts
exist;


                                       41
<PAGE>   48


provided, however, that if a Responsible Officer of the Trustee shall not have
received, at least two Business Days prior to the date upon which by the terms
hereof any such money may become payable for any purpose (including, without
limitation, the payment of the Principal Amount, Issue Price, Redemption Price,
Purchase Price, Change in Control Purchase Price or contingent interest, if any,
as the case may be, in respect of any Security), the notice with respect to such
money provided for in this Section 10.10, then, anything herein contained to the
contrary notwithstanding, the Trustee shall have full power and authority to
receive such money and to apply the same to the 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. The Trustee shall be
entitled to conclusively rely on the delivery to it of a written notice by a
person representing himself to be a holder of Senior Indebtedness (or a trustee
therefor) to establish that such notice has been given by a holder of Senior
Indebtedness (or a trustee therefor). In the event that the Trustee determines
in good faith that further evidence is required with respect to the right of any
person as a holder of Senior Indebtedness to participate in any payment or
distribution pursuant to this Article, the Trustee may request such person to
furnish evidence to the reasonable satisfaction of the Trustee as to the amount
of Senior Indebtedness held by such person, the extent to which such person is
entitled to participate in such payment or distribution and any other facts
pertinent to the rights of such person under this Article, and if such evidence
is not furnished, the Trustee may defer any payment to such Person pending
judicial determination as to the right of such Person to receive such payment.

        SECTION 10.11 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 and the Holders of the Securities shall be entitled to
conclusively rely upon any order or decree entered by any court of competent
jurisdiction in which such insolvency, bankruptcy, receivership, liquidation,
reorganization, dissolution, winding up or similar case or proceeding is
pending, or a certificate of the trustee in bankruptcy, liquidating trustee,
Custodian, receiver, 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 the Senior
Indebtedness and other indebtedness of the Company, the amount thereof or
payable thereon, the amount or amounts paid or distributed thereon and all other
facts pertinent thereto or to this Article.

        SECTION 10.12 Trustee Not Fiduciary for Holders of Senior Indebtedness.
The Trustee shall not be deemed to owe any fiduciary duty to the holders of
Senior Indebtedness and shall not be liable to any such holders if it shall in
good faith pay over or distribute to Holders of Securities or to the Company or
to any other person cash, property or securities to which any holders of Senior
Indebtedness shall be entitled by virtue of this Article or otherwise. The
Trustee shall not be charged with knowledge of the existence of Senior
Indebtedness or of any facts that would prohibit any payment hereunder or that
would permit the resumption of any such payment. With respect to the holders of
Senior Indebtedness, the Trustee undertakes to perform or to observe only such
of its covenants or obligations as are specifically set forth in this Article 10
and no implied covenants or obligations with respect to holders of Senior
Indebtedness shall be read into this Indenture against the Trustee.

        SECTION 10.13 Rights of Trustee as Holder of Senior Indebtedness;
Preservation of Trustee's Rights. The Trustee in its individual capacity shall
be entitled to all the rights set forth in this Article with respect to any
Senior Indebtedness which may at any time be held by it, to the same extent as
any other holder of Senior Indebtedness, and nothing in this Indenture shall
deprive the Trustee of any of its rights as such holder. Nothing in this Article
shall apply to claims of, or payments to, the Trustee under or pursuant to
Section 7.06.

        SECTION 10.14 Article 10 Applicable to Paying Agents. In case at any
time any Paying Agent other than the Trustee shall have been appointed by the
Company and be then acting hereunder, the term "Trustee" as used in this Article
shall in such case (unless the context otherwise requires) be construed as
extending to and including such Paying Agent within its meaning as fully for all
intents and purposes as if such Paying Agent were named in this Article in
addition to or in place of the Trustee; provided, however, that Sections 10.10
and 10.12 shall not apply to the Company or any Affiliate of the Company if it
or such Affiliate acts as Paying Agent.

        SECTION 10.15 Enforcement of Rights Under the Pledge Agreement. No
provision in this Article 10 shall prohibit any Holder from enforcing its rights
under the Pledge Agreement.


                                       42
<PAGE>   49


                              ARTICLE 11 CONVERSION

        SECTION 11.01 Conversion Privilege. A Holder of a Security may convert
such Security into Common Stock until the close of business on the second
Business Day immediately preceding Stated Maturity, subject to the provisions of
this Article 11. The number of shares of Common Stock issuable upon conversion
of a Security per $1,000 of Principal Amount thereof (the "Conversion Rate")
shall be determined in accordance with the provisions of paragraph 10 in the
Securities, subject to adjustment as set forth herein and therein.

        A Holder may convert a portion of the Principal Amount of a Security if
the portion is $1,000 or any integral multiple of $1,000. Provisions of this
Indenture that apply to conversion of all of a Security also apply to conversion
of a portion of a Security.

        "Average Sale Price" means the average of the Sale Prices of the Common
Stock for the shorter of:

            (i) 30 consecutive trading days ending on the last full trading day
            prior to the Time of Determination with respect to the rights,
            warrants or options or distribution in respect of which the Average
            Sale Price is being calculated, or

            (ii) the period (x) commencing on the date next succeeding the first
            public announcement of (a) the issuance of rights, warrants or
            options or (b) the distribution, in each case, in respect of which
            the Average Sale Price is being calculated and (y) proceeding
            through the last full trading day prior to the Time of Determination
            with respect to the rights, warrants or options or distribution in
            respect of which the Average Sale Price is being calculated
            (excluding days within such period, if any, which are not trading
            days), or

            (iii) the period, if any, (x) commencing on the date next succeeding
            the Ex-Dividend Time with respect to the next preceding (a) issuance
            of rights, warrants or options or (b) distribution, in each case,
            for which an adjustment is required by the provisions of Section
            11.06(4), 11.07 or 11.08 and (y) proceeding through the last full
            trading day prior to the Time of Determination with respect to the
            rights, warrants or options or distribution in respect of which the
            Average Sale Price is being calculated (excluding days within such
            period, if any, which are not trading days).

        In the event that the Ex-Dividend Time (or in the case of a subdivision,
combination or reclassification, the effective date with respect thereto) with
respect to a dividend, subdivision, combination or reclassification to which
Section 11.06(1), (2), (3) or (5) applies occurs during the period applicable
for calculating "Average Sale Price" pursuant to the definition in the preceding
sentence, "Average Sale Price" shall be calculated for such period in a manner
determined by the Board of Directors of the Company to reflect the impact of
such dividend, subdivision, combination or reclassification on the Sale Price of
the Common Stock during such period.

        "Time of Determination" means the time and date of the earlier of (i)
the determination of shareholders entitled to receive rights, warrants or
options or a distribution, in each case, to which Section 11.07 or 11.08 applies
and (ii) the time ("Ex-Dividend Time") immediately prior to the commencement of
"ex-dividend" trading for such rights, warrants or options or distribution on
the New York Stock Exchange or such other United States national or regional
exchange or market on which the Common Stock is then listed or quoted.

        SECTION 11.02 Conversion Procedure. To convert a Security a Holder must
satisfy the requirements in paragraph 10 of the Securities. The date on which
the Holder satisfies all those requirements is the conversion date (the
"Conversion Date"). As soon as practicable after the Conversion Date, the
Company shall deliver to the Holder, through the Conversion Agent, a certificate
(or other evidence of ownership) for the number of full shares of Common Stock
issuable upon the conversion and cash in lieu of any fractional share determined
pursuant to Section 11.03. The person in whose name the certificate is
registered shall be treated as a stockholder of record on and after the
Conversion Date; provided, however, that no surrender of a Security on any date
when the stock transfer books of the Company shall be closed shall be effective
to constitute the person or persons entitled to receive the shares of Common
Stock upon such conversion as the record holder or holders of such shares of


                                       43
<PAGE>   50


Common Stock on such date, but such surrender shall be effective to constitute
the person or persons entitled to receive such shares of Common Stock as the
record holder or holders thereof for all purposes at the close of business on
the next succeeding day on which such stock transfer books are open; and such
conversion shall be at the Conversion Rate in effect on the date that such
Security shall have been surrendered for conversion, as if the stock transfer
books of the Company had not been closed. Upon conversion of a Security, such
person shall no longer be a Holder of such Security.

        No payment or adjustment will be made for dividends on, or other
distributions with respect to, any Common Stock except as provided in this
Article 11. On conversion of a Security, that portion of accrued Tax Original
Issue Discount attributable to the period from the Issue Date of the Security
through the Conversion Date and (except as provided below) accrued contingent
interest with respect to the converted Security shall not be cancelled,
extinguished or forfeited, but rather shall be deemed to be paid in full to the
Holder thereof through delivery of the Common Stock (together with the cash
payment, if any, in lieu of fractional shares) in exchange for the Security
being converted pursuant to the provisions hereof; and the fair market value of
such shares of Common Stock (together with any such cash payment in lieu of
fractional shares) shall be treated as issued, to the extent thereof, first in
exchange for Tax Original Issue Discount accrued through the Conversion Date and
accrued contingent interest, and the balance, if any, of such fair market value
of such Common Stock (and any such cash payment) shall be treated as issued in
exchange for the Issue Price of the Security being converted pursuant to the
provisions hereof.

        If the Holder converts more than one Security at the same time, the
number of shares of Common Stock issuable upon the conversion shall be based on
the total Principal Amount of the Securities converted.

        If the last day on which a Security may be converted is a Legal Holiday,
the Security may be surrendered on the next succeeding Business Day that is not
a Legal Holiday; provided, however, the Security shall be deemed to have been
converted and surrendered as of such last day, notwithstanding the occurrence of
a Legal Holiday on such day.

        Upon surrender of a Security that is converted in part, the Company
shall execute, and the Trustee shall authenticate and deliver to the Holder, a
new Security in an authorized denomination equal in Principal Amount to the
unconverted portion of the Security surrendered.

        SECTION 11.03 Fractional Shares. The Company will not issue a fractional
share of Common Stock upon conversion of a Security. Instead, the Company will
deliver cash for the current market value of the fractional share. The current
market value of a fractional share shall be determined, to the nearest 1/1,000th
of a share, by multiplying the Sale Price of the Common Stock, on the last
trading day prior to the Conversion Date, of a full share by the fractional
amount and rounding the product to the nearest whole cent.

        SECTION 11.04 Taxes on Conversion. If a Holder converts a Security, the
Company shall pay any documentary, stamp or similar issue or transfer tax due on
the issue of shares of Common Stock upon the conversion. However, the Holder
shall pay any such tax which is due because the Holder requests the shares to be
issued in a name other than the Holder's name. The Conversion Agent may refuse
to deliver the certificates representing the Common Stock being issued in a name
other than the Holder's name until the Conversion Agent receives a sum
sufficient to pay any tax which will be due because the shares are to be issued
in a name other than the Holder's name. Nothing herein shall preclude any tax
withholding required by law or regulations by the Company.

        SECTION 11.05 Company to Provide Stock. The Company shall, prior to
issuance of any Securities under this Article 11, and from time to time as may
be necessary, reserve out of its authorized but unissued Common Stock a
sufficient number of shares of Common Stock to permit the conversion of the
Securities.

        All shares of Common Stock delivered upon conversion of the Securities
shall be newly issued shares or treasury shares, shall be duly and validly
issued and fully paid and nonassessable and shall be free from preemptive rights
and free of any lien or adverse claim.


                                       44
<PAGE>   51


        The Company will endeavor promptly to comply with all federal and state
securities laws regulating the offer and delivery of shares of Common Stock upon
conversion of Securities, if any, and will list or cause to have quoted such
shares of Common Stock on each national or regional securities exchange or such
other market on which the Common Stock is then listed or quoted.

        SECTION 11.06 Adjustment for Change In Capital Stock. If, after the
Issue Date of the Securities, the Company:

            (i) pays a dividend or makes a distribution on its Common Stock in
            shares of its Common Stock;

            (ii) subdivides its outstanding shares of Common Stock into a
            greater number of shares;

            (iii) combines its outstanding shares of Common Stock into a smaller
            number of shares;

            (iv) pays a dividend or makes a distribution on its Common Stock in
            shares of its Capital Stock (other than Common Stock or rights,
            warrants or options for its Capital Stock); or

            (v) issues by reclassification of its Common Stock any shares of its
            Capital Stock (other than rights, warrants or options for its
            Capital Stock),

then the conversion privilege and the Conversion Rate in effect immediately
prior to such action shall be adjusted so that the Holder of a Security
thereafter converted may receive the number of shares of Capital Stock of the
Company which such Holder would have owned immediately following such action if
such Holder had converted the Security immediately prior to such action.

        The adjustment shall become effective immediately after the record date
in the case of a dividend or distribution and immediately after the effective
date in the case of a subdivision, combination or reclassification.

        If after an adjustment a Holder of a Security upon conversion of such
Security may receive shares of two or more classes of Capital Stock of the
Company, the Conversion Rate shall thereafter be subject to adjustment upon the
occurrence of an action taken with respect to any such class of Capital Stock as
is contemplated by this Article 11 with respect to the Common Stock, on terms
comparable to those applicable to Common Stock in this Article 11.

        SECTION 11.07 Adjustment for Rights Issue.

        If after the Issue Date of the Securities, the Company distributes any
rights, warrants or options to all holders of its Common Stock entitling them,
for a period expiring within 60 days after the record date for such
distribution, to purchase shares of Common Stock at a price per share less than
the Sale Price of the Common Stock as of the Time of Determination, the
Conversion Rate shall be adjusted in accordance with the formula:

                                            (O + N)
                         R'  =  R x ------------------------
                                       (O + [(N x P)/M)]

        where:

        R' = the adjusted Conversion Rate.

        R = the current Conversion Rate.

        O = the number of shares of Common Stock outstanding on the record date
for the distribution to which this Section 11.07 is being applied.

        N = the number of additional shares of Common Stock offered pursuant to
the distribution.


                                       45
<PAGE>   52



        P = the purchase price per share of the additional shares.

        M = the Average Sale Price, minus, in the case of (i) a distribution to
which Section 11.06(4) applies or (ii) a distribution to which Section 11.08
applies, for which, in each case, (x) the record date shall occur on or before
the record date for the distribution to which this Section 11.07 applies and (y)
the Ex-Dividend Time shall occur on or after the date of the Time of
Determination for the distribution to which this Section 11.07 applies, the fair
market value (on the record date for the distribution to which this Section
11.07 applies) of:

            (4) the Capital Stock of the Company distributed in respect of each
            share of Common Stock in such Section 11.06(4) distribution; and

            (5) the assets of the Company or debt securities or any rights,
            warrants or options to purchase securities of the Company
            distributed in respect of each share of Common Stock in such Section
            11.08 distribution.

        The Board of Directors shall determine fair market values for the
purposes of this Section 11.07.

        The adjustment shall become effective immediately after the record date
for the determination of shareholders entitled to receive the rights, warrants
or options to which this Section 11.07 applies. If all of the shares of Common
Stock subject to such rights, warrants or options have not been issued when such
rights, warrants or options expire, then the Conversion Rate shall promptly be
readjusted to the Conversion Rate which would then be in effect had the
adjustment upon the issuance of such rights, warrants or options been made on
the basis of the actual number of shares of Common Stock issued upon the
exercise of such rights, warrants or options.

        No adjustment shall be made under this Section 11.07 if the application
of the formula stated above in this Section 11.07 would result in a value of R'
that is equal to or less than the value of R.

        SECTION 11.08 Adjustment for Other Distributions.

            (a) Subject to 11.08(c), if, after the Issue Date of the Securities,
the Company distributes to all holders of its Common Stock any of its assets
(excluding distributions of Capital Stock) or debt securities or any rights,
warrants or options to purchase securities of the Company (including securities
or cash, but excluding (x) distributions of Capital Stock referred to in Section
11.06 and distributions of rights, warrants or options referred to in Section
11.07 and (y) cash dividends or other cash distributions that are paid out of
consolidated current net earnings or earnings retained in the business as shown
on the books of the Company unless such cash dividends or other cash
distributions are Extraordinary Cash Dividends) the Conversion Rate shall be
adjusted, subject to the provisions of Section 11.08(c), in accordance with the
formula:

                                         R x M
                               R'  =  ---------
                                         M - F

where:

        R' = the adjusted Conversion Rate.

        R = the current Conversion Rate.

        M = the Average Sale Price, minus, in the case of a distribution to
which Section 11.06(4) applies, for which (i) the record date shall occur on or
before the record date for the distribution to which this Section 11.08 applies
and (ii) the Ex-Dividend Time shall occur on or after the date of the Time of
Determination for the distribution to which this Section 11.08 applies, the fair
market value (on the record date for the distribution to which this Section
11.08 applies) of any Capital Stock of the Company distributed in respect of
each share of Common Stock in such Section 11.06(4) distribution.


                                       46
<PAGE>   53


        F = the fair market value (on the record date for the distribution to
which this Section 11.08 applies) of the assets, securities, rights, warrants or
options to be distributed in respect of each share of Common Stock in the
distribution to which this Section 11.08 is being applied (including, in the
case of cash dividends or other cash distributions giving rise to an adjustment,
all such cash distributed concurrently).

            The Board of Directors shall determine fair market values for the
purposes of this Section 11.08.

        The adjustment shall become effective immediately after the record date
for the determination of shareholders entitled to receive the distribution to
which this Section 11.08 applies.

        For purposes of this Section 11.08, the term "Extraordinary Cash
Dividend" shall mean any cash dividend or distribution with respect to the
Common Stock the amount of which, together with the aggregate amount of cash
dividends on the Common Stock to be aggregated with such cash dividend in
accordance with the provisions of this paragraph, equals or exceeds the
threshold percentage set forth in item (i) below. For purposes of item (i)
below, the "Ex-Dividend Measurement Period" with respect to a cash dividend on
the Common Stock shall mean the 365 consecutive day period ending on the date
prior to the Ex-Dividend Time with respect to such cash dividend, and the
"Relevant Cash Dividends" with respect to a cash dividend on the Common Stock
shall mean the cash dividends on the Common Stock with Ex-Dividend Times
occurring in the Ex-Dividend Measurement Period.

            (i) If, upon the date prior to the Ex-Dividend Time with respect to
            a cash dividend on the Common Stock, the aggregate amount of such
            cash dividend together with the amounts of all Relevant Cash
            Dividends equals or exceeds on a per share basis the sum of (a) 5%
            of the Sale Price of the Common Stock on the last trading day
            preceding the date of declaration by the Board of Directors of the
            cash dividend or distribution with respect to which this provision
            is being applied, and (b) an amount equal to the quotient of (x) any
            contingent interest paid on a Security during the Ex-Dividend
            Measurement Period divided by (y) the conversion rate in effect on
            the payment date for such contingent interest, then such cash
            dividend together with all Relevant Cash Dividends, shall be deemed
            to be an Extraordinary Cash Dividend and for purposes of applying
            the formula set forth above in this Section 11.08, the value of "F"
            shall be equal to (y) the aggregate amount of such cash dividend
            together with the amount of all Relevant Cash Dividends, minus (z)
            the aggregate amount of all Relevant Cash Dividends for which a
            prior adjustment in the Conversion Rate was previously made under
            this Section 11.08.

            In making the determinations required by item (i) above, the amount
            of cash dividends paid on a per share basis and the amount of any
            Relevant Cash Dividends specified in item (i) above, shall be
            appropriately adjusted to reflect the occurrence during such period
            of any event described in Section 11.06.

            (b) Subject to Section 11.08(c), if, after the Issue Date, the
Company pays a dividend or makes a distribution to all holders of its Common
Stock consisting of Capital Stock of any class or series, or similar equity
interests, of or relating to a Subsidiary or other business unit of the Company,
the Conversion Rate shall be adjusted in accordance with the formula:

                           R'  =  R x   (1 + F/M)

where:

        R' = the adjusted Conversion Rate.

        R = the current Conversion Rate.

        M = the average of the Sale Prices of the Common Stock for the 10
trading days commencing on and including the fifth trading day after the date on
which "ex-dividend trading" commences for such dividend or distribution on The
New York Stock Exchange or such other national or regional exchange or market
which such securities are then listed or quoted (the "Ex-Dividend Date").


                                       47
<PAGE>   54


        F = the fair market value of the securities distributed in respect of
each share of Common Stock for which this Section 11.08(b) applies.

            (c) In the event that, with respect to any distribution to which
Section 11.08(a) would otherwise apply, the difference between "M-F" is less
than $1.00 or "F" is equal to or greater than "M", then the adjustment provided
by Section 11.08(a) shall not be made and in lieu thereof the provisions of
Section 11.14 shall apply to such distribution.

        SECTION 11.09 When Adjustment May Be Deferred. No adjustment in the
Conversion Rate need be made unless the adjustment would require an increase or
decrease of at least 1% in the Conversion Rate. Any adjustments that are not
made shall be carried forward and taken into account in any subsequent
adjustment.

        All calculations under this Article 11 shall be made to the nearest cent
or to the nearest 1/1,000th of a share, as the case may be.

        SECTION 11.10 When No Adjustment Required. No adjustment need be made
for a transaction referred to in Section 11.06, 11.07, 11.08 or 11.14 if
Securityholders are to participate in the transaction, on a basis and with
notice that the Board of Directors determines to be fair and appropriate in
light of the basis and notice on which holders of Common Stock participate in
the transaction. Such participation by Securityholders may include participation
upon conversion provided that an adjustment shall be made at such time as the
Securityholders are no longer entitled to participate.

        No adjustment need be made for rights to purchase Common Stock pursuant
to a Company plan for reinvestment of dividends or interest.

        No adjustment need be made for a change in the par value or no par value
of the Common Stock.

        To the extent the Securities become convertible pursuant to this Article
11 into cash, no adjustment need be made thereafter as to the cash. Interest
will not accrue on the cash.

        Notwithstanding any provision to the contrary in this Indenture, no
adjustment shall be made in the Conversion Rate to the extent, but only to the
extent, such adjustment results in the following quotient being less than the
par value of the Common Stock: (i) the Issue Price as of the date such
adjustment would otherwise be effective divided by (ii) the Conversion Rate as
so adjusted.

        No adjustment will be made pursuant to this Section 11 which would
result, through the application of two or more provisions hereof, in the
duplication of any adjustment.

        SECTION 11.11 Notice of Adjustment. Whenever the Conversion Rate is
adjusted, the Company shall promptly mail to Securityholders a notice of the
adjustment. The Company shall file with the Trustee and the Conversion Agent
such notice and a certificate from the Company's independent public accountants
briefly stating the facts requiring the adjustment and the manner of computing
it. The certificate shall be conclusive evidence that the adjustment is correct.
Neither the Trustee nor any Conversion Agent shall be under any duty or
responsibility with respect to any such certificate except to exhibit the same
to any Holder desiring inspection thereof.

        SECTION 11.12 Voluntary Increase. The Company from time to time may
increase the Conversion Rate by any amount for any period of time. Whenever the
Conversion Rate is increased, the Company shall mail to Securityholders and file
with the Trustee and the Conversion Agent a notice of the increase. The Company
shall mail the notice at least 15 days before the date the increased Conversion
Rate takes effect. The notice shall state the increased Conversion Rate and the
period it will be in effect.

        A voluntary increase of the Conversion Rate does not change or adjust
the Conversion Rate otherwise in effect for purposes of Section 11.06, 11.07 or
11.08.


                                       48
<PAGE>   55


        SECTION 11.13 Notice of Certain Transactions. If:

            (1) the Company takes any action that would require an adjustment in
            the Conversion Rate pursuant to Section 11.06, 11.07 or 11.08
            (unless no adjustment is to occur pursuant to Section 11.10); or

            (2) the Company takes any action that would require a supplemental
            indenture pursuant to Section 11.14; or

            (3) there is a liquidation or dissolution of the Company;

then the Company shall mail to Securityholders and file with the Trustee and the
Conversion Agent a notice stating the proposed record date for a dividend or
distribution or the proposed effective date of a subdivision, combination,
reclassification, consolidation, merger, binding share exchange, transfer,
liquidation or dissolution. The Company shall file and mail the notice at least
15 days before such date. Failure to file or mail the notice or any defect in it
shall not affect the validity of the transaction.

        SECTION 11.14 Reorganization of Company; Special Distributions. If the
Company is a party to a transaction subject to Section 5.01 (other than a sale
of all or substantially all of the assets of the Company in a transaction in
which the holders of Common Stock immediately prior to such transaction do not
receive securities, cash, property or other assets of the Company or any other
person) or a merger or binding share exchange which reclassifies or changes its
outstanding Common Stock, the person obligated to deliver securities, cash or
other assets upon conversion of Securities shall enter into a supplemental
indenture. If the issuer of securities deliverable upon conversion of Securities
is an Affiliate of the successor Company, that issuer shall join in the
supplemental indenture.

        The supplemental indenture shall provide that the Holder of a Security
may convert it into the kind and amount of securities, cash or other assets
which such Holder would have received immediately after the consolidation,
merger, binding share exchange or transfer if such Holder had converted the
Security immediately before the effective date of the transaction, assuming (to
the extent applicable) that such Holder (i) was not a constituent person or an
Affiliate of a constituent person to such transaction; (ii) made no election
with respect thereto; and (iii) was treated similarly to the plurality of
non-electing Holders. The supplemental indenture shall provide for adjustments
which shall be as nearly equivalent as may be practical to the adjustments
provided for in this Article 11. The successor Company shall mail to
Securityholders a notice briefly describing the supplemental indenture.

        If this Section applies, neither Section 11.06 nor 11.07 applies.

        If the Company makes a distribution to all holders of its Common Stock
of any of its assets, or debt securities or any rights, warrants or options to
purchase securities of the Company that, but for the provisions of Section
11.08(c), would otherwise result in an adjustment in the Conversion Rate
pursuant to the provisions of Section 11.08, then, from and after the record
date for determining the holders of Common Stock entitled to receive the
distribution, a Holder of a Security that converts such Security in accordance
with the provisions of this Indenture shall upon such conversion be entitled to
receive, in addition to the shares of Common Stock into which the Security is
convertible, the kind and amount of securities, cash or other assets comprising
the distribution that such Holder would have received if such Holder had
converted the Security immediately prior to the record date for determining the
holders of Common Stock entitled to receive the distribution.

        SECTION 11.15 Company Determination Final. Any determination that the
Company or the Board of Directors makes pursuant to Sections 11.03, 11.06,
11.07, 11.08, 11.09, 11.10, 11.14 or 11.17 is conclusive.

        SECTION 11.16 Trustee's Adjustment Disclaimer. The Trustee has no duty
to determine when an adjustment under this Article 11 should be made, how it
should be made or what it should be. The Trustee has no


                                       49
<PAGE>   56


duty to determine whether a supplemental indenture under Section 11.14 need be
entered into or whether any provisions of any supplemental indenture are
correct. The Trustee shall not be accountable for and makes no representation as
to the validity or value of any securities or assets issued upon conversion of
Securities. The Trustee shall not be responsible for the Company's failure to
comply with this Article 11. Each Conversion Agent shall have the same
protection under this Section 11.16 as the Trustee.

        SECTION 11.17 Simultaneous Adjustments. In the event that this Article
11 requires adjustments to the Conversion Rate under more than one of Sections
11.06(4), 11.07 or 11.08, and the record dates for the distributions giving rise
to such adjustments shall occur on the same date, then such adjustments shall be
made by applying, first, the provisions of Section 11.06, second, the provisions
of Section 11.08 and, third, the provisions of Section 11.07.

        SECTION 11.18 Successive Adjustments. After an adjustment to the
Conversion Rate under this Article 11, any subsequent event requiring an
adjustment under this Article 11 shall cause an adjustment to the Conversion
Rate as so adjusted.

        SECTION 11.19 Rights Issued in Respect of Common Stock Issued Upon
Conversion. Each share of Common Stock issued upon conversion of Securities
pursuant to this Article 11 shall be entitled to receive the appropriate number
of common stock or preferred stock purchase rights, as the case may be (the
"Rights"), if any, and the certificates representing the Common Stock issued
upon such conversion shall bear such legends, if any, in each case as may be
provided by the terms of any shareholder rights agreement adopted by the
Company, as the same may be amended from time to time (in each case, a "Rights
Agreement"). Provided that such Rights Agreement requires that each share of
Common Stock issued upon conversion of Securities at any time prior to the
distribution of separate certificates representing the Rights be entitled to
receive such Rights, then, notwithstanding anything else to the contrary in this
Article 11, there shall not be any adjustment to the conversion privilege or
Conversion Rate as a result of the issuance of Rights, the distribution of
separate certificates representing the Rights, the exercise or redemption of
such Rights in accordance with any such Rights Agreement, or the termination or
invalidation of such Rights.

                         ARTICLE 12 PAYMENT OF INTEREST

        SECTION 12.01 Interest Payments. If applicable, contingent interest on
any Security that is payable, and is punctually paid or duly provided for, on
any applicable payment date shall be paid in the manner described in paragraph 5
of the Securities at the office or agency of the Company maintained for such
purpose. Each installment of contingent interest on any Security shall be paid
in same-day funds by transfer to an account maintained by the payee located
inside the United States. In the case of a permanent Global Security, contingent
interest payable on any applicable payment date will be paid to the Depositary,
with respect to that portion of such permanent Global Security held for its
account by Cede & Co. for the purpose of permitting such party to credit the
interest received by it in respect of such permanent Global Security to the
accounts of the beneficial owners thereof.

        SECTION 12.02 Defaulted Interest. Except as otherwise specified with
respect to the Securities, any contingent interest on any Security that is
payable, but is not punctually paid or duly provided for, within 30 days
following any applicable payment date (herein called "Defaulted Interest", which
term shall include any accrued and unpaid interest that has accrued on such
defaulted amount in accordance with paragraph 1 of the Securities), shall
forthwith cease to be payable to the registered Holder thereof on the relevant
date described in paragraph 5 of the Securities 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 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 and the date
            of the proposed payment (which shall not be less than 20 days after
            such notice is received by the Trustee), 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


                                       50
<PAGE>   57
            Defaulted Interest or shall make arrangements satisfactory to the
            Trustee for such deposit on or 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 (the "Special Record Date") for the payment of such
            Defaulted Interest which shall be not more than 15 days and not less
            than 10 days prior to the date of the proposed payment and not less
            than 10 days after the receipt by the Trustee of the notice of the
            proposed payment. The Trustee shall promptly notify the Company of
            such Special Record Date and, in the name and at the expense of the
            Company, shall cause notice of the proposed payment of such
            Defaulted Interest and the Special Record Date therefor to be
            mailed, first-class postage prepaid, to each Holder of Securities at
            his address as it appears on the list of Securityholders maintained
            pursuant to Section 2.05 not less than 10 days prior to such Special
            Record Date; notice of the proposed payment of such Defaulted
            Interest and the Special Record Date therefor having been mailed as
            aforesaid, such Defaulted Interest shall be paid to the persons in
            whose names the 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 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.

        SECTION 12.03 Interest Rights Preserved. Subject to the foregoing
provisions of this Article 12 and Section 2.06, 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 contingent interest accrued and
unpaid, and to accrue, which were carried by such other Security.

                            ARTICLE 13 MISCELLANEOUS

        SECTION 13.01 Trust Indenture Act Controls. If any provision of this
Indenture limits, qualifies, or conflicts with another provision which is
required to be included in this Indenture by the TIA, the required provision
shall control.

        SECTION 13.02 Notices. Any request, demand, authorization, notice,
waiver, consent or communication shall be in writing and delivered in person or
by overnight courier or mailed by first-class mail, postage prepaid, addressed
as follows or transmitted by facsimile transmission (confirmed by guaranteed
overnight courier) to the following facsimile numbers:

        if to the Company:

                  Novellus Systems, Inc.
                  4000 North First Street
                  San Jose, California 95134
                  Telephone No.: (408) 943-9700
                  Facsimile No.: (408) 943-3448
                  Attention:  Robin S. Yim

        with a copy to:

                  Morrison & Foerster LLP

                  775 Page Mill Road
                  Palo Alto, California 94304
                  Telephone No.: (650) 813-5641
                  Facsimile: (650) 494-0792


                                       51
<PAGE>   58


                  Attention: Justin Bastian, Esq.

        if to the Trustee:

                  LaSalle Bank National Association
                  135 South LaSalle Street
                  Suite 1960
                  Chicago, Illinois 60603
                  Telephone No. (312) 904-2442
                  Facsimile No. (312) 904-2236
                  Attention: Wayne M. Evans, First Vice President,
                  Corporate Trust Services Division

        The Company or the Trustee by notice given to the other in the manner
provided above may designate additional or different addresses for subsequent
notices or communications.

        Any notice or communication given to a Securityholder shall be mailed to
the Securityholder, by first-class mail, postage prepaid, at the
Securityholder's address as it appears on the registration books of the
Registrar and shall be sufficiently given if so mailed within the time
prescribed.

        Failure to mail a notice or communication to a Securityholder or any
defect in it shall not affect its sufficiency with respect to other
Securityholders. If a notice or communication is mailed in the manner provided
above, it is duly given, whether or not received by the addressee.

        If the Company mails a notice or communication to the Securityholders,
it shall mail a copy to the Trustee and each Registrar, Paying Agent, Conversion
Agent or co-registrar.

        SECTION 13.03 Communication by Holders with Other Holders.
Securityholders may communicate pursuant to TIA Section 312(b) with other
Securityholders with respect to their rights under this Indenture or the
Securities. The Company, the Trustee, the Registrar, the Paying Agent, the
Conversion Agent and anyone else shall have the protection of TIA Section
312(c).

        SECTION 13.04 Certificate and Opinion as to Conditions Precedent. Upon
any request or application by the Company to the Trustee to take any action
under this Indenture, the Company shall furnish to the Trustee:

            (a) an Officers' Certificate of the Company stating that, in the
opinion of the signers, all conditions precedent, if any, provided for in this
Indenture relating to the proposed action have been complied with; and

            (b) an Opinion of Counsel stating that, in the opinion of such
counsel, all such conditions precedent have been complied with.

        SECTION 13.05 Statements Required in Certificate or Opinion. Each
Officers' Certificate or Opinion of Counsel with respect to compliance with a
covenant or condition provided for in this Indenture shall include, without
limitation:

            (1) a statement that each person making such Officers' Certificate
            or Opinion of Counsel has read such covenant or condition;

            (2) a brief statement as to the nature and scope of the examination
            or investigation upon which the statements or opinions contained in
            such Officers' Certificate or Opinion of Counsel are based;


                                       52
<PAGE>   59


            (3) a statement that, in the opinion of each such person, he has
            made such examination or investigation as is necessary to enable
            such person to express an informed opinion as to whether such
            covenant or condition has been complied with; and

            (4) a statement that, in the opinion of such person, such covenant
            or condition has been complied with.

        SECTION 13.06 Severability 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 13.07 Rules by Trustee, Paying Agent, Conversion Agent and
Registrar. The Trustee may make reasonable rules for action by or a meeting of
Securityholders. The Registrar, Conversion Agent and the Paying Agent may make
reasonable rules for their functions.

        SECTION 13.08 Calculations. The calculation of the Purchase Price,
Change in Control Purchase Price, Conversion Rate, Market Price, Sale Price of
the Common Stock and each other calculation to be made hereunder (other than the
LYON Market Price) shall be the obligation of the Company. All calculations made
by the Company as contemplated pursuant to this Section 13.08 shall be final and
binding on the Company and the Holders absent manifest error. The Trustee,
Paying Agent, Conversion Agent and Bid Solicitation Agent shall not be obligated
to recalculate, recompute or confirm any such calculations.

        SECTION 13.09 Legal Holidays. A "Legal Holiday" is any day other than a
Business Day. If any specified date (including a date for giving notice) is a
Legal Holiday, the action shall be taken on the next succeeding day that is not
a Legal Holiday, and, if the action to be taken on such date is a payment in
respect of the Securities, no interest, if any, shall accrue for the intervening
period.

        SECTION 13.10 GOVERNING LAW. THE LAWS OF THE STATE OF NEW YORK SHALL
GOVERN THIS INDENTURE AND THE SECURITIES, WITHOUT REGARD TO CONFLICTS OF LAWS
PROVISIONS THEREOF.

        SECTION 13.11 No Recourse Against Others. A director, officer, employee
or stockholder, as such, of the Company shall not have any liability for any
obligations of the Company under the Securities or this Indenture or for any
claim based on, in respect of or by reason of such obligations or their
creation. By accepting a Security, each Securityholder shall waive and release
all such liability. The waiver and release shall be part of the consideration
for the issue of the Securities.

        SECTION 13.12 Successors. All agreements of the Company in this
Indenture and the Securities shall bind its successors. All agreements of the
Trustee in this Indenture shall bind its successor.

        SECTION 13.13 Multiple Originals. The parties may sign any number of
copies of this Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement. One signed copy is enough to prove this
Indenture.

        SECTION 13.14 Tax Matters.

            (a) Tax Treatment. The parties hereto hereby agree, and each Holder
by its purchase of a Security hereby agrees:

            (1) to treat the Securities as indebtedness of the Company for all
tax purposes;


                                       53
<PAGE>   60

            (2) to treat the Securities as indebtedness that are subject to the
            special regulations governing contingent payment debt instruments
            that are contained in U.S. Treasury Regulation section 1.1275-4; and

            (3) to treat any payment to and receipt by a Holder of Common Stock
            upon conversion of a Security, or upon a redemption of a Security by
            the Company where the Company elects to pay in Common Stock (other
            than that portion of the value of the Common Stock that constitutes
            a repayment of principal), as a contingent payment under Treasury
            Regulation section 1.1275-4(b) that will result in an adjustment
            under Treasury Regulation section 1.1275-4(b)(3)(iv) and Treasury
            Regulation section 1.1275-4(b)(6).

            (b) Comparable Yield and Projected Payment Schedule. Solely for
purposes of applying Treasury Regulation section 1.1275-4 to the Securities:

            (1) for United States Federal income tax purposes, the Company shall
            accrue interest with respect to outstanding Securities as original
            issue discount according to the "noncontingent bond method," as set
            forth in Treasury Regulation Section 1.1275-4(b);

            (2) the Company has determined that the comparable yield, as defined
            in Treasury Regulation section 1.1275-4(b)(4)(i), for the Securities
            is 8.62%, compounded semiannually;

            (3) the Company has determined that the projected payment schedule,
            as defined in Treasury Regulation section 1.1275-4(b)(4)(iii), for
            the Securities consists of the projected payment schedule referred
            to in (5) below;

            (4) the Company acknowledges and agrees, and each Holder and any
            beneficial holder of a Security, by its purchase of a Security shall
            be deemed to acknowledge and agree, that (i) the comparable yield
            and the projected payment schedule are determined on the basis of an
            assumption of linear growth of stock price and a constant dividend
            yield, (ii) the comparable yield and the projected payment schedule
            are not determined for any purpose other than for the purpose of
            applying Treasury Regulation section 1.1275-4(b)(4) to the
            Securities and (iii) the comparable yield and the projected payment
            schedule do not constitute a projection or representation regarding
            the actual amounts payable on the Securities; and

            (5) the projected payment schedule, as defined in Treasury
            Regulation section 1.1275-4(b)(4)(ii) for the Securities is set
            forth in Annex 1 hereto.


                                       54
<PAGE>   61


        IN WITNESS WHEREOF, the undersigned, being duly authorized, have
executed this Indenture on behalf of the respective parties hereto as of the
date first above written.


                                            NOVELLUS SYSTEMS, INC.



                                            By:  /s/ Robert H. Smith
                                            Name:    Robert H. Smith
                                            Title:   Chief Financial Officer and
                                                     Executive Vice President


                                            LASALLE BANK NATIONAL ASSOCIATION



                                            By:  /s/ Wayne Evans
                                            Name:    Wayne Evans
                                            Title:   First Vice President

<PAGE>   62

                                   EXHIBIT A-1

                        [FORM OF FACE OF GLOBAL SECURITY]

FOR PURPOSES OF SECTIONS 1273 AND 1275 OF THE INTERNAL REVENUE CODE, THIS
SECURITY IS ISSUED WITH AN INDETERMINATE AMOUNT OF ORIGINAL ISSUE DISCOUNT FOR
UNITED STATES FEDERAL INCOME TAX PURPOSES. THE ISSUE DATE IS JULY 26, 2001, AND
THE YIELD TO MATURITY FOR PURPOSES OF ACCRUING TAX ORIGINAL ISSUE DISCOUNT IS
8.62% PER ANNUM. THE HOLDER OF THIS SECURITY MAY OBTAIN THE PROJECTED PAYMENT
SCHEDULE BY SUBMITTING A WRITTEN REQUEST TO THE COMPANY FOR SUCH INFORMATION TO
THE ADDRESS SET FORTH IN SECTION 13.02 OF THE WITHIN MENTIONED INDENTURE.

UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY TO THE ISSUER OR ITS AGENT FOR REGISTRATION OF
TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE
NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (AND ANY PAYMENT HEREON IS MADE
TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY), ANY TRANSFER, PLEDGE OR OTHER
USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE
REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

TRANSFERS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS, IN WHOLE BUT
NOT IN PART, TO NOMINEES OF THE DEPOSITORY TRUST COMPANY, OR TO A SUCCESSOR
THEREOF OR SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
SECURITY SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS
SET FORTH IN ARTICLE TWO OF THE INDENTURE REFERRED TO ON THE REVERSE HEREOF.

THIS SECURITY AND THE SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION OF THIS
SECURITY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE "SECURITIES ACT"), OR ANY STATE SECURITIES LAWS. NEITHER THIS SECURITY, THE
SHARES OF COMMON STOCK ISSUABLE UPON CONVERSION OF THIS SECURITY NOR ANY
INTEREST OR PARTICIPATION HEREIN OR THEREIN MAY BE OFFERED, REOFFERED, SOLD,
ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE
ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT
SUBJECT TO, REGISTRATION.

THE HOLDER OF THIS SECURITY, BY ITS ACCEPTANCE HEREOF, AGREES TO OFFER, SELL, OR
OTHERWISE TRANSFER SUCH SECURITY, PRIOR TO THE DATE (THE "RESALE RESTRICTION
TERMINATION DATE") WHICH IS TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUE DATE
HEREOF, THE ISSUANCE OF THE SECURITIES UPON THE EXERCISE OF THE OVER-ALLOTMENT
OPTION GRANTED TO THE INITIAL PURCHASER IN CONNECTION WITH THE ORIGINAL SALE OF
THE SECURITIES AND THE LAST DATE ON WHICH NOVELLUS SYSTEMS, INC. (THE "COMPANY"
OR THE "ISSUER") OR ANY AFFILIATE OF THE COMPANY WAS THE OWNER OF THIS SECURITY
(OR ANY PREDECESSOR OF SUCH SECURITY) ONLY (A) TO THE COMPANY OR ANY SUBSIDIARY
THEREOF, (B) FOR SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO
RULE 144A, TO A PERSON IT REASONABLY BELIEVES IS A "QUALIFIED INSTITUTIONAL
BUYER" AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT THAT PURCHASES FOR ITS
OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHICH
NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A, (C)
PURSUANT TO A REGISTRATION STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER THE
SECURITIES ACT OR (D) PURSUANT TO ANOTHER AVAILABLE EXEMPTION FROM THE
REGISTRATION REQUIREMENTS OF THE SECURITIES ACT, SUBJECT TO THE COMPANY'S AND
THE TRUSTEE'S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER PURSUANT TO CLAUSE
(D) TO REQUIRE THE DELIVERY OF AN OPINION OF COUNSEL, CERTIFICATION AND/OR OTHER
INFORMATION SATISFACTORY TO EACH OF THEM. THIS LEGEND WILL BE REMOVED UPON THE
REQUEST OF THE HOLDER AFTER THE RESALE RESTRICTION TERMINATION DATE.


                                      A-1
<PAGE>   63

THE FOREGOING LEGEND MAY BE REMOVED FROM THIS SECURITY ON SATISFACTION OF THE
CONDITIONS SPECIFIED IN THE INDENTURE.


                                      A-2
<PAGE>   64

                             NOVELLUS SYSTEMS, INC.
                      Liquid Yield Option(TM) Note due 2031
                           (Zero Coupon-Subordinated)

No. R-                                       CUSIP: 670008 AA9
Issue Date: July 26, 2001
Issue Price:  $1,000



       NOVELLUS SYSTEMS, INC., a California corporation, promises to pay to Cede
& Co. or registered assigns, the Principal Amount of ________________ DOLLARS
($____________) on July 26, 2031.

       This Security shall not bear interest except as specified on the other
side of this Security. This Security is convertible as specified on the other
side of this Security.

       Additional provisions of this Security are set forth on the other side of
this Security.

Dated: July 26, 2001                         NOVELLUS SYSTEMS, INC.




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




TRUSTEE'S CERTIFICATE OF
  AUTHENTICATION

LASALLE BANK NATIONAL ASSOCIATION,
as Trustee, certifies that this
is one of the Securities referred
to in the within-mentioned Indenture.


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

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


                                      A-3
<PAGE>   65

                         [FORM OF REVERSE SIDE OF LYON]
                      Liquid Yield Option(TM) Note due 2031
                           (Zero Coupon-Subordinated)


1. Interest.

       This Security shall not bear interest, except as specified in this
paragraph or in paragraphs 5 and 12 hereof. If the Principal Amount hereof or
any portion of such Principal Amount is not paid when due (whether upon
acceleration pursuant to Section 6.02 of the Indenture, upon the date set for
payment of the Redemption Price pursuant to paragraph 6 hereof, upon the date
set for payment of the Purchase Price or Change in Control Purchase Price
pursuant to paragraph 7 hereof or upon the Stated Maturity of this Security) or
if contingent interest, if any, due hereon or any portion of such interest is
not paid when due in accordance with paragraph 5 or 12 hereof, then in each such
case the overdue amount shall, to the extent permitted by law, bear interest at
the rate of 8.62% per annum, compounded semi-annually, which interest shall
accrue from the date such overdue amount was originally due to the date payment
of such amount, including interest thereon, has been made or duly provided for.
All such interest shall be payable on demand.

2. Method of Payment.

       Subject to the terms and conditions of the Indenture, the Company will
make payments in respect of Redemption Prices, Purchase Prices, Change in
Control Purchase Prices and at Stated Maturity to Holders who surrender
Securities to a Paying Agent to collect such payments in respect of the
Securities. The Company will pay cash amounts in money of the United States that
at the time of payment is legal tender for payment of public and private debts.
However, the Company may make such cash payments by check payable in such money.

3. Paying Agent, Conversion Agent, Registrar and Bid Solicitation Agent.

       Initially, LaSalle Bank National Association, a national banking
association (the "Trustee"), will act as Paying Agent, Conversion Agent,
Registrar and Bid Solicitation Agent. The Company may appoint and change any
Paying Agent, Conversion Agent, Registrar or co-registrar or Bid Solicitation
Agent without notice, other than notice to the Trustee. The Company or any of
its Subsidiaries or any of its Affiliates may act as Paying Agent, Conversion
Agent, Registrar or co-registrar. None of the Company, any of its Subsidiaries
or any of its Affiliates shall act as Bid Solicitation Agent.

4. Indenture.

       The Company issued the Securities under an Indenture, dated as of July
26, 2001 (the "Indenture"), between the Company and the Trustee. The terms of
the Securities include those stated in the Indenture and those made part of the
Indenture by reference to the Securities themselves and the Trust Indenture Act
of 1939, as in effect from time to time (the "TIA"). Capitalized terms used
herein and not defined herein have the meanings ascribed thereto in the
Indenture. The Securities are subject to all such terms, and Securityholders are
referred to the Indenture and the TIA for a statement of those terms.

       Except as provided by the provisions of the Pledge Agreement, dated as of
July 26, 2001, between the Company and Union Bank of California, N.A., the
Securities are unsecured obligations of the Company limited to $880,000,000
aggregate Principal Amount (subject to Section 2.07 of the Indenture) and are
subordinated in right of payment to all the Company's existing and future Senior
Indebtedness. The Indenture does not limit other indebtedness of the Company,
secured or unsecured, including Senior Indebtedness.

5. Contingent Interest.

       Subject to the accrual and record date provisions specified in this
paragraph 5, the Company shall pay contingent interest to the Holders during any
six-month period (a "Contingent Interest Period") from July 27 to January 26 and
from January 27 to July 26, with the initial six-month period commencing July
27, 2004, if the


                                      A-4
<PAGE>   66

average LYON Market Price for the Five-Day Period with respect to such
Contingent Interest Period equals 120% or more of the sum of the Issue Price of
a Security to the trading day immediately preceding the first day of the
relevant Contingent Interest Period.

       The amount of contingent interest payable per $1,000 Principal Amount
hereof in respect of any Contingent Interest Period shall equal the sum of any
contingent interest payable in the first and second three-month periods during
such Contingent Interest Period. During any such three-month period, the amount
of any contingent interest payable shall be equal to the greater of (x) .0625%
of the average LYON Market Price for the Five-Day Period with respect to such
Contingent Interest Period and (y) the sum of all Regular Cash Dividends paid by
the Company per share of Common Stock during such three-month period multiplied
by the number of shares of Common Stock into which $1,000 Principal Amount
hereof is convertible pursuant to paragraph 9 hereof as of the accrual date for
such contingent interest.

       Contingent interest, if any, will accrue and be payable to Holders as of
the 15th day (whether or not a Business Day) preceding the last day of the
relevant Contingent Interest Period or, if any Regular Cash Dividends are paid
by the Company during a Contingent Interest Period, to Holders as of the record
date for the related Regular Cash Dividend. Such payments shall be paid on the
last day of the relevant Contingent Interest Period or, if Regular Cash
Dividends are paid by the Company during a Contingent Interest Period, on the
payment date of the related Regular Cash Dividend.

       "Five-Day Period" means, with respect to any Contingent Interest Period,
the five trading days ending on the third trading day immediately preceding the
first day of such Contingent Interest Period; provided, however, if the Company
shall have declared a Regular Cash Dividend on its Common Stock that is payable
during such Contingent Interest Period but for which the record date for
determining stockholders entitled thereto precedes the first day of such
Contingent Interest Period, then "Five-Day Period" shall mean, with respect to
such Contingent Interest Period, the five trading days ending on the third
trading day immediately preceding such record date.

       "Regular Cash Dividends" means quarterly or other periodic cash dividends
on the Company's Common Stock as declared by the Company's Board of Directors as
part of its cash dividend payment practices and that are not designated by them
as extraordinary or special or other nonrecurring dividends.

       "LYON Market Price" means, as of any date of determination, the average
of the secondary market bid quotations per $1,000 Principal Amount obtained by
the Bid Solicitation Agent for $10 million Principal Amount of Securities at
approximately 4:00 p.m., New York City time, on such determination date from
three recognized securities dealers in The City of New York (none of which shall
be an Affiliate of the Company) selected by the Company; provided, however, if
(a) at least three such bids are not obtained by the Bid Solicitation Agent or
(b) in the Company's reasonable judgment, the bid quotations are not indicative
of the secondary market value of the Securities as of such determination date,
then the LYON Market Price for such determination date shall equal the product
of (i) the Conversion Rate in effect as of such determination date multiplied by
(ii) the average Sale Price of the Common Stock for the five trading days ending
on such determination date, appropriately adjusted to take into account the
occurrence, during the period commencing on the first of such trading days
during such five trading day period and ending on such determination date, of
any event described in Section 11.06, 11.07 or 11.08 (subject to the conditions
set forth in Sections 11.09 and 11.10) of the Indenture.

       Upon determination that Holders will be entitled to receive contingent
interest which may become payable during a Contingent Interest Period, on or
prior to the first day of such Contingent Interest Period, the Company shall
issue a press release and publish such information on its web site or by other
appropriate means.

6. Redemption at the Option of the Company.

       No sinking fund is provided for the Securities. The Securities are
redeemable as a whole, or from time to time in part, at any time at the option
of the Company at the Redemption Price, of $1,000 per $1,000 Principal Amount of
Securities, provided that the Securities are not redeemable prior to July 26,
2004.


                                      A-5
<PAGE>   67

       In addition to the Redemption Price payable with respect to all
Securities or portions thereof to be redeemed as of a Redemption Date, the
Holders of such Securities (or portions thereof) shall be entitled to receive
accrued and unpaid contingent interest, if any, with respect thereto, which
contingent interest shall be paid in cash on the Redemption Date.

7. Purchase by the Company at the Option of the Holder.

       Subject to the terms and conditions of the Indenture, the Company shall
become obligated to purchase, at the option of the Holder, the Securities held
by such Holder on July 26, 2002, July 26, 2006, July 26, 2011, July 26, 2016,
July 26, 2021 and July 26, 2026, at the Purchase Price of $1,000 per $1,000
Principal Amount, upon delivery of a Purchase Notice containing the information
set forth in the Indenture, at any time from the opening of business on the date
that is at least 20 Business Days prior to such Purchase Date until the close of
business on the Second Business Day immediately preceding such Purchase Date and
upon delivery of the Securities to the Paying Agent by the Holder as set forth
in the Indenture.

       The Purchase Price may be paid, at the option of the Company, in cash or
by the issuance and delivery of shares of Common Stock of the Company, or in any
combination thereof, provided that the Purchase Price on July 26, 2002 shall be
paid solely in cash.

       At the option of the Holder and subject to the terms and conditions of
the Indenture, the Company shall become obligated to purchase all or a portion
of the Securities in integral multiples of $1,000 Principal Amount held by such
Holder no later than 35 Business Days after the occurrence of a Change in
Control of the Company occurring on or prior to July 26, 2006 for a Change in
Control Purchase Price for each $1,000 Principal Amount for such Securities
equal to the Issue Price to the Change in Control Purchase Date, which Change in
Control Purchase Price shall be paid in cash only.

       In addition to the Purchase Price or Change in Control Purchase Price, as
the case may be, payable with respect to all Securities or portions thereof to
be purchased as of the Purchase Date or the Change in Control Purchase Date, as
the case may be, the Holders of such Securities (or portions thereof) shall be
entitled to receive accrued and unpaid contingent interest, if any, with respect
thereto, which contingent interest shall be paid in cash promptly following the
later of the Purchase Date or the Change in Control Purchase Date, as the case
may be, and the time of delivery of such Securities to the Paying Agent pursuant
to the Indenture.

       Holders have the right to withdraw any Purchase Notice or Change in
Control Purchase Notice, as the case may be, by delivering to the Paying Agent a
written notice of withdrawal in accordance with the provisions of the Indenture.

       If cash (and/or securities if permitted under the Indenture) sufficient
to pay the Purchase Price or Change in Control Purchase Price, as the case may
be, together with any accrued and unpaid contingent interest, with respect to
all Securities or portions thereof to be purchased as of the Purchase Date or
the Change in Control Purchase Date, as the case may be, is deposited with the
Paying Agent on the Purchase Date or the Change in Control Purchase Date, as the
case may be, contingent interest, if any, shall cease to accrue on such
Securities (or portions thereof) immediately after such Purchase Date or Change
in Control Purchase Date, as the case may be, and the Holder thereof shall have
no other rights as such (other than the right to receive the Purchase Price or
Change in Control Purchase Price, as the case may be, and accrued and unpaid
contingent interest, if any, upon surrender of such Security).

8. Notice of Redemption.

       Notice of redemption will be mailed at least 15 days but not more than 60
days before the Redemption Date to each Holder of Securities to be redeemed at
the Holder's registered address. If money sufficient to pay the Redemption Price
of, and accrued and unpaid contingent interest, if any, with respect to, all
Securities (or portions thereof) to be redeemed on the Redemption Date is
deposited with the Paying Agent prior to or on the Redemption Date, immediately
after such Redemption Date, contingent interest, if any, shall cease to accrue
on such Securities


                                      A-6
<PAGE>   68

or portions thereof. Securities in denominations larger than $1,000 of Principal
Amount may be redeemed in part but only in integral multiples of $1,000 of
Principal Amount.

9. Subordination.

       The Securities are subordinated to all existing and future Senior
Indebtedness. To the extent provided in the Indenture, Senior Indebtedness must
be paid before the Securities may be paid (other than to the extent payments
made on the Securities are made from funds then held pursuant to the Pledge
Agreement for the benefit of Holders of the Securities in respect of the
Purchase Price payable on July 26, 2002). The Indenture does not limit the
present or future amount of Senior Indebtedness the Company may have. The
Company agrees, and each Securityholder by accepting a Security agrees, to the
subordination of such Security and authorizes the Trustee to give it effect and
appoints the Trustee as attorney-in-fact for such purpose.

10. Conversion.

       Subject to the provisions of this paragraph 10 and the Indenture, if, as
of the last day of any calendar quarter beginning with the quarter ended
September 30, 2001, the closing Sale Price of the Common Stock for at least 20
trading days in a period of 30 consecutive trading days ending on the last
trading day of such calendar quarter is more than 110% of the Conversion Price,
then on and after the first day of the immediately succeeding quarter, a Holder
may convert this Security into Common Stock at any time until the close of
business on the second Business Day immediately preceding Stated Maturity. If
the Company is a party to a consolidation, merger or binding share exchange
pursuant to which Common Stock would be converted into cash, securities or other
property, or sale of all or substantially all of the Company's assets, this
Security may be surrendered for conversion at any time from and after the date
which is 15 days prior to the anticipated effective date of the transaction
until 15 days after the actual date of such transaction and, at the effective
time, the right to convert this Security into shares of Common Stock will be
changed into a right to convert it into the kind and amount of cash, securities
or other property of the Company or another person which the Holder would have
received if the Holder had converted this Security immediately prior to the
transaction. If this Security or any part hereof is subject to redemption by the
Company in accordance with paragraph 6 hereof, a Holder may convert this
Security into Common Stock at any time until the close of business on the second
Business Day immediately preceding the related Redemption Date.

       A Security in respect of which a Holder has delivered a Purchase Notice
exercising the option of such Holder to require the Company to purchase such
Security may be converted only if such notice of exercise is withdrawn in
accordance with the terms of the Indenture.

       The initial Conversion Rate is 13.09504 shares of Common Stock per $1,000
Principal Amount, subject to adjustment for certain events described in the
Indenture or this paragraph 10. The Conversion Price is, as of any date of
determination, the Principal Amount hereof divided by the Conversion Rate then
in effect. The Company will deliver cash or a check in lieu of any fractional
share of Common Stock.

       To convert a Security, a Holder must (1) complete and manually sign the
conversion notice below (or complete and manually sign a facsimile of such
notice) and deliver such notice to the Conversion Agent, (2) surrender the
Security to the Conversion Agent, (3) furnish appropriate endorsements and
transfer documents if required by the Conversion Agent, the Company or the
Trustee and (4) pay any transfer or similar tax, if required.

       A Holder may only convert a portion of a Security pursuant to the terms
of this paragraph 10 and in accordance with the Indenture if the Principal
Amount of such portion is $1,000 or any integral multiple of $1,000. No payment
or adjustment will be made for dividends on the Common Stock except as provided
herein and in the Indenture. On conversion of a Security, that portion of
accrued Tax Original Issue Discount attributable to the period from the Issue
Date through the Conversion Date and (except as provided above) accrued
contingent interest with respect to the converted Security shall not be
cancelled, extinguished or forfeited, but rather shall be deemed to be paid in
full to the Holder thereof through the delivery of the Common Stock (together
with the cash payment, if any, in lieu of fractional shares) in exchange for the
Security being converted pursuant to the terms hereof; and the fair market value
of such shares of Common Stock (together with any such cash payment in lieu of
fractional shares) shall be treated as issued, to the extent thereof, first in
exchange for Tax Original Issue Discount and accrued contingent interest, and
the balance, if any, of such fair market value of such Common Stock (and any
such cash


                                      A-7
<PAGE>   69

payment) shall be treated as issued in exchange for the Issue Price of the
Security being converted pursuant to the provisions hereof.

       The Conversion Rate, in accordance with the provisions of the Indenture,
will be adjusted for dividends or distributions on Common Stock payable in
Common Stock or other Capital Stock; subdivisions, combinations or certain
reclassifications of Common Stock; distributions to all holders of Common Stock
of certain rights to purchase Common Stock for a period expiring within 60 days
of such distribution at less than the Sale Price of the Common Stock at the Time
of Determination; and distributions to such holders of assets or debt securities
of the Company or certain rights to purchase securities of the Company
(excluding certain cash dividends or distributions). However, no adjustment need
be made if Securityholders may participate in the transaction or in certain
other cases. The Company from time to time may voluntarily increase the
Conversion Rate.

       If the Company is a party to a consolidation, merger or binding share
exchange or a transfer of all or substantially all of its assets, or upon
certain distributions described in the Indenture, the right to convert a
Security into Common Stock may be changed into a right to convert it into
securities, cash or other assets of the Company or another person.

       The Conversion Rate will not be adjusted for any contingent interest.


11. Conversion Arrangement on Call for Redemption.

       Any Securities called for redemption, unless surrendered for conversion
before the close of business on the second Business Day prior to the Redemption
Date, may be deemed to be purchased from the Holders of such Securities at an
amount not less than the Redemption Price, by one or more investment bankers or
other purchasers who may agree with the Company to purchase such Securities from
the Holders, to convert them into Common Stock of the Company and to make
payment for such Securities to the Trustee in trust for such Holders.

12. Defaulted Interest.

       Except as otherwise specified with respect to the Securities, any
Defaulted Interest on any Security shall forthwith cease to be payable to the
registered Holder thereof on the relevant Regular Record Date or accrual date,
as the case may be, by virtue of having been such Holder, and such Defaulted
Interest may be paid by the Company as provided in Section 12.02 of the
Indenture.

13. Denominations; Transfer; Exchange.

       The Securities are in fully registered form, without coupons, in
denominations of $1,000 of Principal Amount and integral multiples of $1,000. A
Holder may transfer or exchange Securities in accordance with the Indenture. The
Registrar may require a Holder, among other things, to furnish appropriate
endorsements and transfer documents and to pay any taxes and fees required by
law or permitted by the Indenture. The Registrar need not transfer or exchange
any Securities selected for redemption (except, in the case of a Security to be
redeemed in part, the portion of the Security not to be redeemed) or any
Securities in respect of which a Purchase Notice or Change in Control Purchase
Notice has been given and not withdrawn (except, in the case of a Security to be
purchased in part, the portion of the Security not to be purchased) or any
Securities for a period of 15 days before the mailing of a notice of redemption
of Securities to be redeemed.

14. Persons Deemed Owners.

       The registered Holder of this Security may be treated as the owner of
this Security for all purposes.

15. Unclaimed Money or Securities.

       The Trustee and the Paying Agent shall return to the Company upon written
request any money or securities held by them for the payment of any amount with
respect to the Securities that remains unclaimed for one


                                      A-8
<PAGE>   70

year, subject to applicable unclaimed property laws. After return to the
Company, Holders entitled to the money or securities must look to the Company
for payment as general creditors unless an applicable abandoned property law
designates another person.

16. Amendment; Waiver.

       Subject to certain exceptions set forth in the Indenture, (i) the
Indenture or the Securities may be amended with the written consent of the
Holders of at least a majority in aggregate Principal Amount of the Securities
at the time outstanding and (ii) certain Defaults may be waived with the written
consent of the Holders of a majority in aggregate Principal Amount of the
Securities at the time outstanding. Subject to certain exceptions set forth in
the Indenture, without the consent of any Securityholder, the Company and the
Trustee may amend the Indenture or the Securities to cure any ambiguity,
omission, defect or inconsistency, or to comply with Article 5 or Section 11.14
of the Indenture, to secure the Company's obligations under this Security or to
add to the Company's covenants for the benefit of the Securityholders or to
surrender any right or power conferred, or to comply with any requirement of the
SEC in connection with the qualification of the Indenture under the TIA, or as
necessary in connection with the registration of the Securities under the
Securities Act.

17. Defaults and Remedies.

       Under the Indenture, Events of Default include (i) default in the payment
of contingent interest when the same becomes due and payable or of interest
which becomes due and payable upon exercise by the Company of its option
provided for in paragraph 12 hereof and Article 10 of the Indenture which
default in either case continues for 30 days; (ii) default in payment of the
Principal Amount, Issue Price, Redemption Price, Purchase Price or Change in
Control Purchase Price, as the case may be, in respect of the Securities when
the same becomes due and payable; (iii) the Company fails either to deliver
shares of Common Stock (or to pay cash in lieu of fractional shares) in
accordance with the terms of the Indenture when such Common Stock (or cash in
lieu of fractional shares) is required to be delivered, upon conversion of a
Security and such failure is not remedied for a period of 10 days; (iv) failure
by the Company to comply with any of its other agreements in the Indenture or
the Securities, subject to notice and lapse of time; (v) (a) failure of the
Company to make any payment by the end of any applicable grace period after
maturity of indebtedness in an amount (taken together with amounts in (b) below)
in excess of $10,000,000, or (b) the acceleration of indebtedness in an amount
(taken together with amounts in (a) above) in excess of $10,000,000 because of a
default with respect to such indebtedness without such indebtedness having been
discharged or such acceleration having been cured, waived, rescinded or
annulled, subject to notice and lapse of time; provided, however, that if any
such failure or acceleration referred to in (a) or (b) above shall cease or be
cured, waived, rescinded or annulled, then the Event of Default by reason
thereof shall be deemed not to be continuing; and (v) certain events of
bankruptcy or insolvency with respect to the Company or any Material Subsidiary.
If an Event of Default occurs and is continuing, the Trustee, or the Holders of
at least 25% in aggregate Principal Amount of the Securities at the time
outstanding, may declare all the Securities to be due and payable immediately.
Certain events of bankruptcy or insolvency are Events of Default which will
result in the Securities becoming due and payable immediately upon the
occurrence of such Events of Default.

       Securityholders may not enforce the Indenture or the Securities except as
provided in the Indenture. The Trustee may refuse to enforce the Indenture or
the Securities unless it receives indemnity or security reasonably satisfactory
to it. Subject to certain limitations, Holders of a majority in aggregate
Principal Amount of the Securities at the time outstanding may direct the
Trustee in its exercise of any trust or power. The Trustee may withhold from
Securityholders notice of any continuing Default (except a Default in payment of
amounts specified in clause (i) or (ii) above) if it determines that withholding
notice is in their interests.

18. Trustee Dealings with the Company.

       Subject to certain limitations imposed by the TIA, the Trustee under the
Indenture, in its individual or any other capacity, may become the owner or
pledgee of Securities and may otherwise deal with and collect obligations owed
to it by the Company or its Affiliates and may otherwise deal with the Company
with the same rights it would have if it were not Trustee.


                                      A-9
<PAGE>   71

19. No Recourse Against Others.

       A director, officer, employee or shareholder, as such, of the Company
shall not have any liability for any obligations of the Company under the
Securities or the Indenture or for any claim based on, in respect of or by
reason of such obligations or their creation. By accepting a Security, each
Securityholder waives and releases all such liability. The waiver and release
are part of the consideration for the issue of the Securities.

20. Authentication.

       This Security shall not be valid until an authorized signatory of the
Trustee manually signs the Trustee's Certificate of Authentication on the other
side of this Security.

21. Abbreviations.

       Customary abbreviations may be used in the name of a Securityholder or an
assignee, such as TEN COM (=tenants in common), TEN ENT (=tenants by the
entireties), JT TEN (=joint tenants with right of survivorship and not as
tenants in common), CUST (=custodian), and U/G/M/A (=Uniform Gift to Minors
Act).

22. GOVERNING LAW.

       THE LAW OF THE STATE OF NEW YORK SHALL GOVERN THE INDENTURE AND THIS
SECURITY, WITHOUT REGARD TO CONFLICTS OF LAW PRINCIPLES THEREOF.

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


                                      A-10
<PAGE>   72

       The Company will furnish to any Securityholder upon written request and
without charge a copy of the Indenture which has in it the text of this Security
in larger type. Requests may be made to:

                Novellus Systems, Inc.
                4000 North First Street
                San Jose, California 95134
                Att: Investor Relations


<TABLE>
<S>                                                              <C>
                ASSIGNMENT FORM                                                 CONVERSION NOTICE

To assign this Security, fill in the form below:                 To convert this Security into Common Stock of the
                                                                 Company, check the box:

I or we assign and transfer this Security to                                           [ ]

--------------------------------------------                     To convert only part of this Security, state the
--------------------------------------------                     Principal Amount to be converted (which must be
                                                                 $1,000 or an integral multiple of $1,000):
(Insert assignee's soc. sec. or tax ID no.)
                                                                 $
                                                                  ----------------------------
--------------------------------------------
                                                                 If you want the stock certificate made out in another
--------------------------------------------                     person's name, fill in the form below:

                                                                 -----------------------------------------------------
--------------------------------------------                     --------------------------------------
(Print or type assignee's name, address and zip code)            (Insert other person's soc. sec. or tax ID no.)

and irrevocably appoint                                          ------------------------------------------

_____________________ agent to transfer this                     ------------------------------------------
Security on the books of the Company.  The agent
may substitute another to act for him.                           ------------------------------------------

                                                                 ------------------------------------------
                                                                 (Print or type other person's name, address and
                                                                 zip code)
</TABLE>


<PAGE>   73

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

Date: _____________________  Your Signature:____________________________________

--------------------------------------------------------------------------------
     (Sign exactly as your name appears on the other side of this Security)


Signature Guarantee:
                      ------------------------------------
                               SIGNATURE GUARANTEE

Signatures must be guaranteed by an "eligible guarantor institution" meeting the
requirements of the Registrar, which requirements include membership or
participation in the Security Transfer Agent Medallion Program ("STAMP") or such
other "signature guarantee program" as may be determined by the Registrar in
addition to, or in substitution for, STAMP, all in accordance with the
Securities Exchange Act of 1934, as amended.