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                                                                     EXHIBIT 4.6

                           ONYX PHARMACEUTICALS, INC.
                                     ISSUER

                                       AND

                             WELLS FARGO BANK, N.A.
                                     TRUSTEE

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

                                    INDENTURE

                             DATED AS OF [-], 200__

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

                             SENIOR DEBT SECURITIES

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                                TABLE OF CONTENTS

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ARTICLE 1  DEFINITIONS..........................................................................................      1

         Section 1.01 Definitions of Terms......................................................................      1

ARTICLE 2  ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES........................      5

         Section 2.01 Designation and Terms of Securities.......................................................      5

         Section 2.02 Form of Securities and Trustee's Certificate..............................................      7

         Section 2.03 Denominations: Provisions for Payment.....................................................      7

         Section 2.04 Execution and Authentication..............................................................      9

         Section 2.05 Registration of Transfer and Exchange.....................................................     10

         Section 2.06 Temporary Securities......................................................................     11

         Section 2.07 Mutilated, Destroyed, Lost or Stolen Securities...........................................     11

         Section 2.08 Cancellation..............................................................................     12

         Section 2.09 Benefits of Indenture.....................................................................     12

         Section 2.10 Authenticating Agent......................................................................     12

         Section 2.11 Global Securities.........................................................................     13

ARTICLE 3  REDEMPTION OF SECURITIES AND SINKING FUND PROVISIONS.................................................     14

         Section 3.01 Redemption................................................................................     14

         Section 3.02 Notice of Redemption......................................................................     14

         Section 3.03 Payment Upon Redemption...................................................................     15

         Section 3.04 Sinking Fund..............................................................................     16

         Section 3.05 Satisfaction of Sinking Fund Payments with Securities.....................................     16

         Section 3.06 Redemption of Securities for Sinking Fund.................................................     16

ARTICLE 4  COVENANTS............................................................................................     17

         Section 4.01 Payment of Principal, Premium and Interest................................................     17

         Section 4.02 Maintenance of Office or Agency...........................................................     17

         Section 4.03 Paying Agents.............................................................................     17

         Section 4.04 Appointment to Fill Vacancy in Office of Trustee..........................................     18

         Section 4.05 Compliance with Consolidation Provisions..................................................     18

ARTICLE 5  SECURITYHOLDERS' LISTS AND REPORTS BY THE COMPANY AND THE TRUSTEE....................................     19
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                                TABLE OF CONTENTS
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         Section 5.01 Company to Furnish Trustee Names and Addresses of Securityholders.........................     19

         Section 5.02 Preservation Of Information; Communications With Securityholders..........................     19

         Section 5.03 Reports by the Company....................................................................     19

         Section 5.04 Reports by the Trustee....................................................................     20

ARTICLE 6  REMEDIES OF THE TRUSTEE AND SECURITYHOLDERS ON EVENT OF DEFAULT......................................     20

         Section 6.01 Events of Default.........................................................................     20

         Section 6.02 Collection of Indebtedness and Suits for Enforcement by Trustee...........................     22

         Section 6.03 Application of Moneys or Property Collected...............................................     23

         Section 6.04 Limitation on Suits.......................................................................     24

         Section 6.05 Rights and Remedies Cumulative; Delay or Omission Not Waiver..............................     24

         Section 6.06 Control by Securityholders................................................................     25

         Section 6.07 Undertaking to Pay Costs..................................................................     25

ARTICLE 7  CONCERNING THE TRUSTEE...............................................................................     26

         Section 7.01 Certain Duties and Responsibilities of Trustee............................................     26

         Section 7.02 Certain Rights of Trustee.................................................................     27

         Section 7.03 Trustee Not Responsible for Recitals or Issuance or Securities............................     28

         Section 7.04 May Hold Securities.......................................................................     28

         Section 7.05 Moneys Held in Trust......................................................................     29

         Section 7.06 Compensation and Reimbursement............................................................     29

         Section 7.07 Reliance on Officers' Certificate.........................................................     29

         Section 7.08 Disqualification; Conflicting Interests...................................................     30

         Section 7.09 Corporate Trustee Required; Eligibility...................................................     30

         Section 7.10 Resignation and Removal; Appointment of Successor.........................................     30

         Section 7.11 Acceptance of Appointment By Successor....................................................     31

         Section 7.12 Merger, Conversion, Consolidation or Succession to Business...............................     33

         Section 7.13 Preferential Collection of Claims Against the Company.....................................     33

         Section 7.14 Notice of Default.........................................................................     33

ARTICLE 8  CONCERNING THE SECURITYHOLDERS.......................................................................     33
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                                TABLE OF CONTENTS
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         Section 8.01 Evidence of Action by Securityholders.....................................................     33

         Section 8.02 Proof of Execution by Securityholders.....................................................     34

         Section 8.03 Who May be Deemed Owners..................................................................     34

         Section 8.04 Certain Securities Owned by Company Disregarded...........................................     35

         Section 8.05 Actions Binding on Future Securityholders.................................................     35

ARTICLE 9  SUPPLEMENTAL INDENTURES..............................................................................     35

         Section 9.01 Supplemental Indentures Without the Consent of Securityholders............................     35

         Section 9.02 Supplemental Indentures With Consent of Securityholders...................................     37

         Section 9.03 Effect of Supplemental Indentures.........................................................     37

         Section 9.04 Securities Affected by Supplemental Indentures............................................     37

         Section 9.05 Execution of Supplemental Indentures......................................................     38

ARTICLE 10  SUCCESSOR ENTITY....................................................................................     38

         Section 10.01 Company May Consolidate, Etc.............................................................     38

         Section 10.02 Successor Entity Substituted.............................................................     39

         Section 10.03 Evidence of Consolidation, Etc. to Trustee...............................................     39

ARTICLE 11  SATISFACTION AND DISCHARGE..........................................................................     39

         Section 11.01 Satisfaction and Discharge of Indenture..................................................     39

         Section 11.02 Discharge of Obligations.................................................................     40

         Section 11.03 Deposited Moneys to be Held in Trust.....................................................     40

         Section 11.04 Payment of Moneys Held by Paying Agents..................................................     40

         Section 11.05 Repayment to Company.....................................................................     41

ARTICLE 12  IMMUNITY OF INCORPORATORS, STOCKHOLDERS, OFFICERS AND DIRECTORS.....................................     41

         Section 12.01 No Recourse..............................................................................     41

ARTICLE 13  MISCELLANEOUS PROVISIONS............................................................................     42

         Section 13.01 Effect on Successors and Assigns.........................................................     42

         Section 13.02 Actions by Successor.....................................................................     42

         Section 13.03 Surrender of Company Powers..............................................................     42

         Section 13.04 Notices..................................................................................     42

         Section 13.05 Governing Law............................................................................     42
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                                TABLE OF CONTENTS
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         Section 13.06 Treatment of Securities as Debt..........................................................     42

         Section 13.07 Compliance Certificates and Opinions.....................................................     43

         Section 13.08 Payments on Business Days................................................................     43

         Section 13.09 Conflict with Trust Indenture Act........................................................     43

         Section 13.10 Counterparts.............................................................................     43

         Section 13.11 Separability.............................................................................     43

         Section 13.12 Compliance Certificates..................................................................     44
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(1)   This Table of Contents does not constitute part of the Indenture and shall
      not have any bearing on the interpretation of any of its terms or
      provisions.

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                                    INDENTURE

      INDENTURE, dated as of [-], 200__, among Onyx Pharmaceuticals, Inc., a
Delaware corporation (the "Company"), and Wells Fargo Bank, N.A., as trustee
(the "Trustee"):

      WHEREAS, for its lawful corporate purposes, the Company has duly
authorized the execution and delivery of this Indenture to provide for the
issuance of debt securities (hereinafter referred to as the "Securities"), in an
unlimited aggregate principal amount to be issued from time to time in one or
more series as in this Indenture provided, as registered Securities without
coupons, to be authenticated by the certificate of the Trustee;

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

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

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

                                   ARTICLE 1

                                   DEFINITIONS

      SECTION 1.01 DEFINITIONS OF TERMS.

      The terms defined in this Section (except as in this Indenture or any
indenture supplemental hereto otherwise expressly provided or unless the context
otherwise requires) for all purposes of this Indenture and of any indenture
supplemental hereto shall have the respective meanings specified in this Section
and shall include the plural as well as the singular. All other terms used in
this Indenture that are defined in the Trust Indenture Act of 1939, as amended,
or that are by reference in such Act defined in the Securities Act of 1933, as
amended (except as herein or any indenture supplemental hereto otherwise
expressly provided or unless the context otherwise requires), shall have the
meanings assigned to such terms in said Trust Indenture Act and in said
Securities Act as in force at the date of the execution of this instrument.

      "AUTHENTICATING AGENT" means an authenticating agent with respect to all
or any of the series of Securities appointed by the Trustee pursuant to Section
2.10.

      "BANKRUPTCY LAW" means Title 11, U.S. Code, or any similar federal or
state law for the relief of debtors.

      "BOARD OF DIRECTORS" means the Board of Directors of the Company or any
duly authorized committee of such Board.

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

      "BUSINESS DAY" means, with respect to any series of Securities, any day
other than a day on which federal or state banking institutions in the Borough
of Manhattan, the City of New York, or in the city of the Corporate Trust Office
of the Trustee, are authorized or obligated by law, executive order or
regulation to close.

      "CERTIFICATE" means a certificate signed by any Officer. The Certificate
need not comply with the provisions of Section 13.07.

      "COMPANY" means Onyx Pharmaceuticals, Inc., a corporation duly organized
and existing under the laws of the State of Delaware, and, subject to the
provisions of Article Ten, shall also include its successors and assigns.

      "CORPORATE TRUST OFFICE" means the office of the Trustee at which, at any
particular time, its corporate trust business shall be principally administered,
which office at the date hereof is located at Wells Fargo Bank, N.A., Sixth &
Marquette, MAC N9303-120, Minneapolis, MN 55479, except that whenever a
provision herein refers to an office or agency of the Trustee in the Borough of
Manhattan, The City of New York, such office is located, at the date hereof, at
Wells Fargo Corporate Trust, c/o The Depository Trust Company, 1st Floor - TADS
Department, 55 Water Street, New York, NY 10041.

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

      "DEFAULT" means any event, act or condition that with notice or lapse of
time, or both, would constitute an Event of Default.

      "DEPOSITARY" means, with respect to Securities of any series for which the
Company shall determine that such Securities will be issued as a Global
Security, The Depository Trust Company, New York, New York, another clearing
agency, or any successor registered as a clearing agency under the Securities
and Exchange Act of 1934, as amended (the "Exchange Act"), or other applicable
statute or regulation, which, in each case, shall be designated by the Company
pursuant to either Section 2.01 or 2.11.

      "EVENT OF DEFAULT" means, with respect to Securities of a particular
series, any event specified in Section 6.01, continued for the period of time,
if any, therein designated.

      "GLOBAL SECURITY" means, with respect to any series of Securities, a
Security executed by the Company and delivered by the Trustee to the Depositary
or pursuant to the Depositary's instruction, all in accordance with the
Indenture, which shall be registered in the name of the Depositary or its
nominee.

      "GOVERNMENTAL OBLIGATIONS" means securities that are (a) direct
obligations of the United States of America for the payment of which its full
faith and credit is pledged or (b) obligations

                                       2
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of a Person controlled or supervised by and acting as an agency or
instrumentality of the United States of America, the payment of which is
unconditionally guaranteed as a full faith and credit obligation by the United
States of America that, in either case, are not callable or redeemable at the
option of the issuer thereof at any time prior to the stated maturity of the
Securities, and shall also include a depositary receipt issued by a bank or
trust company as custodian with respect to any such Governmental Obligation or a
specific payment of principal of or interest on any such Governmental Obligation
held by such custodian for the account of the holder of such depositary receipt;
provided, however, that (except as required by law) such custodian is not
authorized to make any deduction from the amount payable to the holder of such
depositary receipt from any amount received by the custodian in respect of the
Governmental Obligation or the specific payment of principal of or interest on
the Governmental Obligation evidenced by such depositary receipt.

      "HEREIN", "HEREOF" and "HEREUNDER", and other words of similar import,
refer to this Indenture as a whole and not to any particular Article, Section or
other subdivision.

      "INDENTURE" means this instrument as originally executed or as it may from
time to time be supplemented or amended by one or more indentures supplemental
hereto entered into in accordance with the terms hereof.

      "INTEREST PAYMENT DATE", when used with respect to any installment of
interest on a Security of a particular series, means the date specified in such
Security or in a Board Resolution or in an indenture supplemental hereto with
respect to such series as the fixed date on which an installment of interest
with respect to Securities of that series is due and payable.

      "OFFICER" means, with respect to the Company, the chairman of the Board of
Directors, a chief executive officer, a president, a chief financial officer,
chief operating officer, any executive vice president, any senior vice
president, any vice president, the treasurer or any assistant treasurer, the
controller or any assistant controller or the secretary or any assistant
secretary.

      "OFFICERS' CERTIFICATE" means a certificate signed by any two Officers.
Each such certificate shall include the statements provided for in Section
13.07, if and to the extent required by the provisions thereof.

      "OPINION OF COUNSEL" means an opinion in writing subject to customary
exceptions of legal counsel, who may be an employee of or counsel for the
Company, that is delivered to the Trustee in accordance with the terms hereof.
Each such opinion shall include the statements provided for in Section 13.07, if
and to the extent required by the provisions thereof.

      "OUTSTANDING", when used with reference to Securities of any series,
means, subject to the provisions of Section 8.04, as of any particular time, all
Securities of that series theretofore authenticated and delivered by the Trustee
under this Indenture, except (a) Securities theretofore canceled by the Trustee
or any paying agent, or delivered to the Trustee or any paying agent for
cancellation or that have previously been canceled; (b) Securities or portions
thereof for the payment or redemption of which moneys or Governmental
Obligations in the necessary amount shall have been deposited in trust with the
Trustee or with any paying agent (other than the

                                       3
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Company) or shall have been set aside and segregated in trust by the Company (if
the Company shall act as its own paying agent); provided, however, that if such
Securities or portions of such Securities are to be redeemed prior to the
maturity thereof, notice of such redemption shall have been given as in Article
Three provided, or provision satisfactory to the Trustee shall have been made
for giving such notice; and (c) Securities in lieu of or in substitution for
which other Securities shall have been authenticated and delivered pursuant to
the terms of Section 2.07.

      "PERSON" means any individual, corporation, partnership, joint venture,
joint-stock company, limited liability company, association, trust,
unincorporated organization, any other entity or organization, including a
government or political subdivision or an agency or instrumentality thereof.

      "PREDECESSOR SECURITY" of any particular Security means every previous
Security evidencing all or a portion of the same debt as that evidenced by such
particular Security; and, for the purposes of this definition, any Security
authenticated and delivered under Section 2.07 in lieu of a lost, destroyed or
stolen Security shall be deemed to evidence the same debt as the lost, destroyed
or stolen Security.

      "RESPONSIBLE OFFICER" when used with respect to the Trustee means the
chairman of its board of directors, the chief executive officer, the president,
any vice president, the secretary, the treasurer, any trust officer, any
corporate trust officer or any other officer or assistant officer of the Trustee
customarily performing functions similar to those performed by the Persons who
at the time shall be such officers, respectively, or to whom any corporate trust
matter is referred because of his or her knowledge of and familiarity with the
particular subject.

      "SECURITIES" means the debt Securities authenticated and delivered under
this Indenture.

      "SECURITYHOLDER", "holder of Securities", "registered holder", or other
similar term, means the Person or Persons in whose name or names a particular
Security shall be registered on the books of the Company kept for that purpose
in accordance with the terms of this Indenture.

      "SECURITY REGISTER" and "SECURITY REGISTRAR" shall have the meanings as
set forth in Section 2.05.

      "SUBSIDIARY" means, with respect to any Person, (i) any corporation at
least a majority of whose outstanding Voting Stock shall at the time be owned,
directly or indirectly, by such Person or by one or more of its Subsidiaries or
by such Person and one or more of its Subsidiaries, (ii) any general
partnership, joint venture or similar entity, at least a majority of whose
outstanding partnership or similar interests shall at the time be owned by such
Person, or by one or more of its Subsidiaries, or by such Person and one or more
of its Subsidiaries and (iii) any limited partnership of which such Person or
any of its Subsidiaries is a general partner.

      "TRUSTEE" means Wells Fargo Bank, N.A., and, subject to the provisions of
Article Seven, shall also include its successors and assigns, and, if at any
time there is more than one Person acting in such capacity hereunder, "Trustee"
shall mean each such Person. The term "Trustee" as used with respect to a
particular series of the Securities shall mean the trustee with respect to that
series.

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<PAGE>

      "TRUST INDENTURE ACT" means the Trust Indenture Act of 1939, as amended.

      "VOTING STOCK", as applied to stock of any Person, means shares,
interests, participations or other equivalents in the equity interest (however
designated) in such Person having ordinary voting power for the election of a
majority of the directors (or the equivalent) of such Person, other than shares,
interests, participations or other equivalents having such power only by reason
of the occurrence of a contingency.

                                   ARTICLE 2

               ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION
                           AND EXCHANGE OF SECURITIES

      SECTION 2.01 DESIGNATION AND TERMS OF SECURITIES.

            (a)   The aggregate principal amount of Securities that may be
authenticated and delivered under this Indenture is unlimited. The Securities
may be issued in one or more series up to the aggregate principal amount of
Securities of that series from time to time authorized by or pursuant to a Board
Resolution or pursuant to one or more indentures supplemental hereto. Prior to
the initial issuance of Securities of any series, there shall be established in
or pursuant to a Board Resolution, and set forth in an Officers' Certificate, or
established in one or more indentures supplemental hereto:

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

                  (2)   any limit upon the aggregate principal amount of the
Securities of that series that may be authenticated and delivered under this
Indenture (except for Securities authenticated and delivered upon registration
of transfer of, or in exchange for, or in lieu of, other Securities of that
series);

                  (3)   the date or dates on which the principal of the
Securities of the series is payable, any original issue discount that may apply
to the Securities of that series upon their issuance, the principal amount due
at maturity, and the place(s) of payment;

                  (4)   the rate or rates at which the Securities of the series
shall bear interest or the manner of calculation of such rate or rates, if any;

                  (5)   the date or dates from which such interest shall accrue,
the Interest Payment Dates on which such interest will be payable or the manner
of determination of such Interest Payment Dates, the place(s) of payment, and
the record date for the determination of holders to whom interest is payable on
any such Interest Payment Dates or the manner of determination of such record
dates;

                  (6)   the right, if any, to extend the interest payment
periods and the duration of such extension;

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

                  (8)   the obligation, if any, of the Company to redeem or
purchase Securities of the series pursuant to any sinking fund, mandatory
redemption, or analogous provisions (including payments made in cash in
satisfaction of future sinking fund obligations) or at the option of a holder
thereof and the period or periods within which, the price or prices at which,
and the terms and conditions upon which, Securities of the series shall be
redeemed or purchased, in whole or in part, pursuant to such obligation;

                  (9)   the form of the Securities of the series including the
form of the Certificate of Authentication for such series;

                  (10)  if other than denominations of one thousand U.S. dollars
($1,000) or any integral multiple thereof, the denominations in which the
Securities of the series shall be issuable;

                  (11)  any and all other terms (including terms, to the extent
applicable, relating to any auction or remarketing of the Securities of that
series and any security for the obligations of the Company with respect to such
Securities) with respect to such series (which terms shall not be inconsistent
with the terms of this Indenture, as amended by any supplemental indenture)
including any terms which may be required by or advisable under United States
laws or regulations or advisable in connection with the marketing of Securities
of that series;

                  (12)  whether the Securities are issuable as a Global Security
and, in such case, the terms and the identity of the Depositary for such series;

                  (13)  whether the Securities will be convertible into or
exchangeable for shares of common stock or other securities of the Company or
any other Person and, if so, the terms and conditions upon which such Securities
will be so convertible or exchangeable, including the conversion or exchange
price, as applicable, or how it will be calculated and may be adjusted, any
mandatory or optional (at the Company's option or the holders' option)
conversion or exchange features, and the applicable conversion or exchange
period;

                  (14)  if other than the principal amount thereof, the portion
of the principal amount of Securities of the series which shall be payable upon
declaration of acceleration of the maturity thereof pursuant to Section 6.01;

                  (15)  any additional or different Events of Default or
restrictive covenants (which may include, among other restrictions, restrictions
on the Company's ability or the ability of the Company's Subsidiaries to: incur
additional indebtedness; issue additional securities; create liens; pay
dividends or make distributions in respect of their capital stock; redeem
capital stock; place restrictions on such Subsidiaries placing restrictions on
their ability to pay dividends, make distributions or transfer assets; make
investments or other restricted payments; sell or otherwise dispose of assets;
enter into sale-leaseback transactions; engage in transactions with stockholders
and affiliates; issue or sell stock of their Subsidiaries; or effect a

                                       6
<PAGE>

consolidation or merger) or financial covenants (which may include, among other
financial covenants, financial covenants that require the Company and its
Subsidiaries to maintain specified interest coverage, fixed charge, cash
flow-based or asset-based ratios) provided for with respect to the Securities of
the series;

                  (16)  if other than dollars, the coin or currency in which the
Securities of the series are denominated (including, but not limited to, foreign
currency);

                  (17)  the terms and conditions, if any, upon which the Company
shall pay amounts in addition to the stated interest, premium, if any and
principal amounts of the Securities of the series to any Securityholder that is
not a "United States person" for federal tax purposes; and

                  (18)  any restrictions on transfer, sale or assignment of the
Securities of the series.

      All Securities of any one series shall be substantially identical except
as to denomination and except as may otherwise be provided in or pursuant to any
such Board Resolution or in any indentures supplemental hereto.

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

      Securities of any particular series may be issued at various times, with
different dates on which the principal or any installment of principal is
payable, with different rates of interest, if any, or different methods by which
rates of interest may be determined, with different dates on which such interest
may be payable and with different redemption dates.

      SECTION 2.02 FORM OF SECURITIES AND TRUSTEE'S CERTIFICATE.

      The Securities of any series and the Trustee's certificate of
authentication to be borne by such Securities shall be substantially of the
tenor and purport as set forth in one or more indentures supplemental hereto or
as provided in a Board Resolution, and set forth in an Officers' Certificate,
and they may have such letters, numbers or other marks of identification or
designation and such legends or endorsements printed, lithographed or engraved
thereon as the Company may deem appropriate and as are not inconsistent with the
provisions of this Indenture, or as may be required to comply with any law or
with any rule or regulation made pursuant thereto or with any rule or regulation
of any securities exchange on which Securities of that series may be listed, or
to conform to usage.

      SECTION 2.03 DENOMINATIONS: PROVISIONS FOR PAYMENT.

      The Securities shall be issuable as registered Securities and in the
denominations of one thousand U.S. dollars ($1,000) or any integral multiple
thereof, subject to Section 2.01(a)(10). The Securities of a particular series
shall bear interest payable on the dates and at the rate

                                       7
<PAGE>

specified with respect to that series. Subject to Section 2.01(a)(16), the
principal of and the interest on the Securities of any series, as well as any
premium thereon in case of redemption thereof prior to maturity, shall be
payable in the coin or currency of the United States of America that at the time
is legal tender for public and private debt, at the office or agency of the
Company maintained for that purpose in the Borough of Manhattan, the City and
State of New York. Each Security shall be dated the date of its authentication.
Interest on the Securities shall be computed on the basis of a 360-day year
composed of twelve 30-day months.

      The interest installment on any Security that is payable, and is
punctually paid or duly provided for, on any Interest Payment Date for
Securities of that series shall be paid to the Person in whose name said
Security (or one or more Predecessor Securities) is registered at the close of
business on the regular record date for such interest installment. In the event
that any Security of a particular series or portion thereof is called for
redemption and the redemption date is subsequent to a regular record date with
respect to any Interest Payment Date and prior to such Interest Payment Date,
interest on such Security will be paid upon presentation and surrender of such
Security as provided in Section 3.03.

      Any interest on any Security that is payable, but is not punctually paid
or duly provided for, on any Interest Payment Date for Securities of the same
series (herein called "Defaulted Interest") shall forthwith cease to be payable
to the registered holder on the relevant regular record date by virtue of having
been such holder; and such Defaulted Interest shall be paid by the Company, at
its election, as provided in clause (1) or clause (2) below:

                  (1)   The Company may make payment of any Defaulted Interest
on Securities to the Persons in whose names such Securities (or their respective
Predecessor Securities) are registered at the close of business on a special
record date for the payment of such Defaulted Interest, which shall be fixed in
the following manner: the Company shall notify the Trustee in writing of the
amount of Defaulted Interest proposed to be paid on each such Security and the
date of the proposed payment, and at the same time the Company shall deposit
with the Trustee an amount of money equal to the aggregate amount proposed to be
paid in respect of such Defaulted Interest or shall make arrangements
satisfactory to the Trustee for such deposit prior to the date of the proposed
payment, such money when deposited to be held in trust for the benefit of the
Persons entitled to such Defaulted Interest as in this clause provided.
Thereupon the Trustee shall fix a special record date for the payment of such
Defaulted Interest which shall not be more than 15 nor 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 Securityholder at his or her address as it
appears in the Security Register (as hereinafter defined), 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
such Securities (or their respective Predecessor Securities) are registered on
such special record date.

                  (2)   The Company may make payment of any Defaulted Interest
on any Securities in any other lawful manner not inconsistent with the
requirements of any securities

                                       8
<PAGE>

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.

      Unless otherwise set forth in a Board Resolution or one or more indentures
supplemental hereto establishing the terms of any series of Securities pursuant
to Section 2.01 hereof, the term "regular record date" as used in this Section
with respect to a series of Securities and any Interest Payment Date for such
series shall mean either the fifteenth day of the month immediately preceding
the month in which an Interest Payment Date established for such series pursuant
to Section 2.01 hereof shall occur, if such Interest Payment Date is the first
day of a month, or the first day of the month in which an Interest Payment Date
established for such series pursuant to Section 2.01 hereof shall occur, if such
Interest Payment Date is the fifteenth day of a month, whether or not such date
is a Business Day.

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

      SECTION 2.04 EXECUTION AND AUTHENTICATION.

      The Securities shall be signed on behalf of the Company by one of its
Officers. Signatures may be in the form of a manual or facsimile signature.

      The Company may use the facsimile signature of any Person who shall have
been an Officer, notwithstanding the fact that at the time the Securities shall
be authenticated and delivered or disposed of such Person shall have ceased to
be such an officer of the Company. The Securities may contain such notations,
legends or endorsements required by law, stock exchange rule or usage. Each
Security shall be dated the date of its authentication by the Trustee.

      A Security shall not be valid until authenticated manually by an
authorized signatory of the Trustee, or by an Authenticating Agent. Such
signature shall be conclusive evidence that the Security so authenticated has
been duly authenticated and delivered hereunder and that the holder is entitled
to the benefits of this Indenture. At any time and from time to time after the
execution and delivery of this Indenture, the Company may deliver Securities of
any series executed by the Company to the Trustee for authentication, together
with a written order of the Company for the authentication and delivery of such
Securities, signed by an Officer, and the Trustee in accordance with such
written order shall authenticate and deliver such Securities.

      In authenticating such Securities and accepting the additional
responsibilities under this Indenture in relation to such Securities, the
Trustee shall be entitled to receive, and (subject to Section 7.01) shall be
fully protected in relying upon, an Opinion of Counsel stating that the form and
terms thereof have been established in conformity with the provisions of this
Indenture.

      The Trustee shall not be required to authenticate such Securities if the
issue of such Securities pursuant to this Indenture will affect the Trustee's
own rights, duties or immunities

                                       9
<PAGE>

under the Securities and this Indenture or otherwise in a manner that is not
reasonably acceptable to the Trustee.

      SECTION 2.05 REGISTRATION OF TRANSFER AND EXCHANGE.

            (a)   Securities of any series may be exchanged upon presentation
thereof at the office or agency of the Company designated for such purpose in
the Borough of Manhattan, the City and State of New York, for other Securities
of such series of authorized denominations, and for a like aggregate principal
amount, upon payment of a sum sufficient to cover any tax or other governmental
charge in relation thereto, all as provided in this Section. In respect of any
Securities so surrendered for exchange, the Company shall execute, the Trustee
shall authenticate and such office or agency shall deliver in exchange therefor
the Security or Securities of the same series that the Securityholder making the
exchange shall be entitled to receive, bearing numbers not contemporaneously
outstanding.

            (b)   The Company shall keep, or cause to be kept, at its office or
agency designated for such purpose in the Borough of Manhattan, the City and
State of New York, or such other location designated by the Company, a register
or registers (herein referred to as the "Security Register") in which, subject
to such reasonable regulations as it may prescribe, the Company shall register
the Securities and the transfers of Securities as in this Article provided and
which at all reasonable times shall be open for inspection by the Trustee. The
registrar for the purpose of registering Securities and transfer of Securities
as herein provided shall be appointed as authorized by Board Resolution (the
"Security Registrar").

      Upon surrender for transfer of any Security at the office or agency of the
Company designated for such purpose, the Company shall execute, the Trustee
shall authenticate and such office or agency shall deliver in the name of the
transferee or transferees a new Security or Securities of the same series as the
Security presented for a like aggregate principal amount.

      All Securities presented or surrendered for exchange or registration of
transfer, as provided in this Section, shall be accompanied (if so required by
the Company or the Security Registrar) by a written instrument or instruments of
transfer, in form satisfactory to the Company or the Security Registrar, duly
executed by the registered holder or by such holder's duly authorized attorney
in writing.

            (c)   Except as provided pursuant to Section 2.01 pursuant to a
Board Resolution, and set forth in an Officers' Certificate, or established in
one or more indentures supplemental to this Indenture, no service charge shall
be made for any exchange or registration of transfer of Securities, or issue of
new Securities in case of partial redemption of any series, but the Company may
require payment of a sum sufficient to cover any tax or other governmental
charge in relation thereto, other than exchanges pursuant to Section 2.06,
Section 3.03(b) and Section 9.04 not involving any transfer.

            (d)   The Company shall not be required (i) to issue, exchange or
register the transfer of any Securities during a period beginning at the opening
of business 15 days before the day of the mailing of a notice of redemption of
less than all the Outstanding Securities of the same series and ending at the
close of business on the day of such mailing, nor (ii) to register the

                                       10
<PAGE>

transfer of or exchange any Securities of any series or portions thereof called
for redemption, other than the unredeemed portion of any such Securities being
redeemed in part. The provisions of this Section 2.05 are, with respect to any
Global Security, subject to Section 2.11 hereof.

      SECTION 2.06 TEMPORARY SECURITIES.

      Pending the preparation of definitive Securities of any series, the
Company may execute, and the Trustee shall authenticate and deliver, temporary
Securities (printed, lithographed or typewritten) of any authorized
denomination. Such temporary Securities shall be substantially in the form of
the definitive Securities in lieu of which they are issued, but with such
omissions, insertions and variations as may be appropriate for temporary
Securities, all as may be determined by the Company. Every temporary Security of
any series shall be executed by the Company and be authenticated by the Trustee
upon the same conditions and in substantially the same manner, and with like
effect, as the definitive Securities of such series. Without unnecessary delay
the Company will execute and will furnish definitive Securities of such series
and thereupon any or all temporary Securities of such series may be surrendered
in exchange therefor (without charge to the holders), at the office or agency of
the Company designated for the purpose in the Borough of Manhattan, the City and
State of New York, and the Trustee shall authenticate and such office or agency
shall deliver in exchange for such temporary Securities an equal aggregate
principal amount of definitive Securities of such series, unless the Company
advises the Trustee to the effect that definitive Securities need not be
executed and furnished until further notice from the Company. Until so
exchanged, the temporary Securities of such series shall be entitled to the same
benefits under this Indenture as definitive Securities of such series
authenticated and delivered hereunder.

      SECTION 2.07 MUTILATED, DESTROYED, LOST OR STOLEN SECURITIES.

      In case any temporary or definitive Security shall become mutilated or be
destroyed, lost or stolen, the Company (subject to the next succeeding sentence)
shall execute, and upon the Company's request the Trustee (subject as aforesaid)
shall authenticate and deliver, a new Security of the same series, bearing a
number not contemporaneously outstanding, in exchange and substitution for the
mutilated Security, or in lieu of and in substitution for the Security so
destroyed, lost or stolen. In every case the applicant for a substituted
Security shall furnish to the Company and the Trustee such security or indemnity
as may be required by them to save each of them harmless, and, in every case of
destruction, loss or theft, the applicant shall also furnish to the Company and
the Trustee evidence to their satisfaction of the destruction, loss or theft of
the applicant's Security and of the ownership thereof. The Trustee may
authenticate any such substituted Security and deliver the same upon the written
request or authorization of any officer of the Company. Upon the issuance of any
substituted Security, 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.

      In case any Security that has matured or is about to mature shall become
mutilated or be destroyed, lost or stolen, the Company may, instead of issuing a
substitute Security, pay or authorize the payment of the same (without surrender
thereof except in the case of a mutilated Security) if the applicant for such
payment shall furnish to the Company and the Trustee such

                                       11
<PAGE>

security or indemnity as they may require to save them harmless, and, in case of
destruction, loss or theft, evidence to the satisfaction of the Company and the
Trustee of the destruction, loss or theft of such Security and of the ownership
thereof.

      Every replacement Security issued pursuant to the provisions of this
Section shall constitute an additional contractual obligation of the Company
whether or not the mutilated, destroyed, lost or stolen Security shall be found
at any time, or be enforceable by anyone, and shall be entitled to all the
benefits of this Indenture equally and proportionately with any and all other
Securities of the same series duly issued hereunder. All Securities shall be
held and owned upon the express condition that the foregoing provisions are
exclusive with respect to the replacement or payment of mutilated, destroyed,
lost or stolen Securities, and shall preclude (to the extent lawful) any and all
other rights or remedies, notwithstanding any law or statute existing or
hereafter enacted to the contrary with respect to the replacement or payment of
negotiable instruments or other securities without their surrender.

      SECTION 2.08 CANCELLATION.

      All Securities surrendered for the purpose of payment, redemption,
exchange or registration of transfer shall, if surrendered to the Company or any
paying agent, be delivered to the Trustee for cancellation, or, if surrendered
to the Trustee, shall be cancelled by it, and no Securities shall be issued in
lieu thereof except as expressly required or permitted by any of the provisions
of this Indenture. In the absence of such request the Trustee may dispose of
canceled Securities in accordance with its standard procedures and deliver a
certificate of disposition to the Company. If the Company shall otherwise
acquire any of the Securities, however, such acquisition shall not operate as a
redemption or satisfaction of the indebtedness represented by such Securities
unless and until the same are delivered to the Trustee for cancellation.

      SECTION 2.09 BENEFITS OF INDENTURE.

      Nothing in this Indenture or in the Securities, express or implied, shall
give or be construed to give to any Person, other than the parties hereto and
the holders of the Securities any legal or equitable right, remedy or claim
under or in respect of this Indenture, or under any covenant, condition or
provision herein contained; all such covenants, conditions and provisions being
for the sole benefit of the parties hereto and of the holders of the Securities.

      SECTION 2.10 AUTHENTICATING AGENT.

      So long as any of the Securities of any series remain Outstanding there
may be an Authenticating Agent for any or all such series of Securities which
the Trustee shall have the right to appoint. Said Authenticating Agent shall be
authorized to act on behalf of the Trustee to authenticate Securities of such
series issued upon exchange, transfer or partial redemption thereof, and
Securities so authenticated shall be entitled to the benefits of this Indenture
and shall be valid and obligatory for all purposes as if authenticated by the
Trustee hereunder. All references in this Indenture to the authentication of
Securities by the Trustee shall be deemed to include authentication by an
Authenticating Agent for such series. Each Authenticating Agent shall be
acceptable to the Company and shall be a corporation that has a combined capital
and surplus, as most recently reported or determined by it, sufficient under the
laws of any

                                       12
<PAGE>

jurisdiction under which it is organized or in which it is doing business to
conduct a trust business, and that is otherwise authorized under such laws to
conduct such business and is subject to supervision or examination by federal or
state authorities. If at any time any Authenticating Agent shall cease to be
eligible in accordance with these provisions, it shall resign immediately.

      Any Authenticating Agent may at any time resign by giving written notice
of resignation to the Trustee and to the Company. The Trustee may at any time
(and upon request by the Company shall) terminate the agency of any
Authenticating Agent by giving written notice of termination to such
Authenticating Agent and to the Company. Upon resignation, termination or
cessation of eligibility of any Authenticating Agent, the Trustee may appoint an
eligible successor Authenticating Agent acceptable to the Company. Any successor
Authenticating Agent, upon acceptance of its appointment hereunder, shall become
vested with all the rights, powers and duties of its predecessor hereunder as if
originally named as an Authenticating Agent pursuant hereto.

      SECTION 2.11 GLOBAL SECURITIES.

            (a)   If the Company shall establish pursuant to Section 2.01 that
the Securities of a particular series are to be issued as a Global Security,
then the Company shall execute and the Trustee shall, in accordance with Section
2.04, authenticate and deliver, a Global Security that (i) shall represent, and
shall be denominated in an amount equal to the aggregate principal amount of,
all of the Outstanding Securities of such series, (ii) shall be registered in
the name of the Depositary or its nominee, (iii) shall be delivered by the
Trustee to the Depositary or pursuant to the Depositary's instruction and (iv)
shall bear a legend substantially to the following effect: "Except as otherwise
provided in Section 2.11 of the Indenture, this Security may be transferred, in
whole but not in part, only to another nominee of the Depositary or to a
successor Depositary or to a nominee of such successor Depositary."

            (b)   Notwithstanding the provisions of Section 2.05, the Global
Security of a series may be transferred, in whole but not in part and in the
manner provided in Section 2.05, only to another nominee of the Depositary for
such series, or to a successor Depositary for such series selected or approved
by the Company or to a nominee of such successor Depositary.

            (c)   If at any time the Depositary for a series of the Securities
notifies the Company that it is unwilling or unable to continue as Depositary
for such series or if at any time the Depositary for such series shall no longer
be registered or in good standing under the Exchange Act, or other applicable
statute or regulation, and a successor Depositary for such series is not
appointed by the Company within 90 days after the Company receives such notice
or becomes aware of such condition, as the case may be, or if an Event of
Default has occurred and is continuing and the Company has received a request
from the Depositary, this Section 2.11 shall no longer be applicable to the
Securities of such series and the Company will execute, and subject to Section
2.04, the Trustee will authenticate and deliver the Securities of such series in
definitive registered form without coupons, in authorized denominations, and in
an aggregate principal amount equal to the principal amount of the Global
Security of such series in exchange for such Global Security. In addition, the
Company may at any time determine that the Securities of any series shall no
longer be represented by a Global Security and that the provisions of this

                                       13
<PAGE>

Section 2.11 shall no longer apply to the Securities of such series. In such
event the Company will execute and, subject to Section 2.04, the Trustee, upon
receipt of an Officers' Certificate evidencing such determination by the
Company, will authenticate and deliver the Securities of such series in
definitive registered form without coupons, in authorized denominations, and in
an aggregate principal amount equal to the principal amount of the Global
Security of such series in exchange for such Global Security. Upon the exchange
of the Global Security for such Securities in definitive registered form without
coupons, in authorized denominations, the Global Security shall be canceled by
the Trustee. Such Securities in definitive registered form issued in exchange
for the Global Security pursuant to this Section 2.11(c) shall be registered in
such names and in such authorized denominations as the Depositary, pursuant to
instructions from its direct or indirect participants or otherwise, shall
instruct the Trustee. The Trustee shall deliver such Securities to the
Depositary for delivery to the Persons in whose names such Securities are so
registered.

                                   ARTICLE 3

              REDEMPTION OF SECURITIES AND SINKING FUND PROVISIONS

      SECTION 3.01 REDEMPTION.

      The Company may redeem the Securities of any series issued hereunder on
and after the dates and in accordance with the terms established for such series
pursuant to Section 2.01 hereof.

      SECTION 3.02 NOTICE OF REDEMPTION.

            (a)   In case the Company shall desire to exercise such right to
redeem all or, as the case may be, a portion of the Securities of any series in
accordance with any right the Company reserved for itself to do so pursuant to
Section 2.01 hereof, the Company shall, or shall cause the Trustee to, give
notice of such redemption to holders of the Securities of such series to be
redeemed by mailing, first class postage prepaid, a notice of such redemption
not less than 30 days and not more than 90 days before the date fixed for
redemption of that series to such holders at their last addresses as they shall
appear upon the Security Register, unless a shorter period is specified in the
Securities to be redeemed. Any notice that is mailed in the manner herein
provided shall be conclusively presumed to have been duly given, whether or not
the registered holder receives the notice. In any case, failure duly to give
such notice to the holder of any Security of any series designated for
redemption in whole or in part, or any defect in the notice, shall not affect
the validity of the proceedings for the redemption of any other Securities of
such series or any other series. In the case of any redemption of Securities
prior to the expiration of any restriction on such redemption provided in the
terms of such Securities or elsewhere in this Indenture, the Company shall
furnish the Trustee with an Officers' Certificate evidencing compliance with any
such restriction.

      Each such notice of redemption shall specify the date fixed for redemption
and the redemption price at which Securities of that series are to be redeemed,
and shall state that payment of the redemption price of such Securities to be
redeemed will be made at the office or agency of the Company in the Borough of
Manhattan, the City and State of New York, upon

                                       14
<PAGE>

presentation and surrender of such Securities, that interest accrued to the date
fixed for redemption will be paid as specified in said notice, that from and
after said date interest will cease to accrue and that the redemption is for a
sinking fund, if such is the case. If less than all the Securities of a series
are to be redeemed, the notice to the holders of Securities of that series to be
redeemed in part shall specify the particular Securities to be so redeemed.

      In case any Security is to be redeemed in part only, the notice that
relates to such Security shall state the portion of the principal amount thereof
to be redeemed, and shall state that on and after the redemption date, upon
surrender of such Security, a new Security or Securities of such series in
principal amount equal to the unredeemed portion thereof will be issued.

            (b)   If less than all the Securities of a series are to be
redeemed, the Company shall give the Trustee at least 45 days' notice (unless a
shorter notice shall be satisfactory to the Trustee) in advance of the date
fixed for redemption as to the aggregate principal amount of Securities of the
series to be redeemed, and thereupon the Trustee shall select, by lot or in such
other manner as it shall deem appropriate and fair in its discretion and that
may provide for the selection of a portion or portions (equal to one thousand
U.S. dollars ($1,000) or any integral multiple thereof) of the principal amount
of such Securities of a denomination larger than $1,000, the Securities to be
redeemed and shall thereafter promptly notify the Company in writing of the
numbers of the Securities to be redeemed, in whole or in part. The Company may,
if and whenever it shall so elect, by delivery of instructions signed on its
behalf by an Officer, instruct the Trustee or any paying agent to call all or
any part of the Securities of a particular series for redemption and to give
notice of redemption in the manner set forth in this Section, such notice to be
in the name of the Company or its own name as the Trustee or such paying agent
may deem advisable. In any case in which notice of redemption is to be given by
the Trustee or any such paying agent, the Company shall deliver or cause to be
delivered to, or permit to remain with, the Trustee or such paying agent, as the
case may be, such Security Register, transfer books or other records, or
suitable copies or extracts therefrom, sufficient to enable the Trustee or such
paying agent to give any notice by mail that may be required under the
provisions of this Section.

      SECTION 3.03 PAYMENT UPON REDEMPTION.

            (a)   If the giving of notice of redemption shall have been
completed as above provided, the Securities or portions of Securities of the
series to be redeemed specified in such notice shall become due and payable on
the date and at the place stated in such notice at the applicable redemption
price, together with interest accrued to the date fixed for redemption and
interest on such Securities or portions of Securities shall cease to accrue on
and after the date fixed for redemption, unless the Company shall default in the
payment of such redemption price and accrued interest with respect to any such
Security or portion thereof. On presentation and surrender of such Securities on
or after the date fixed for redemption at the place of payment specified in the
notice, said Securities shall be paid and redeemed at the applicable redemption
price for such series, together with interest accrued thereon to the date fixed
for redemption (but if the date fixed for redemption is an interest payment
date, the interest installment payable on such date shall be payable to the
registered holder at the close of business on the applicable record date
pursuant to Section 2.03).

                                       15
<PAGE>

            (b)   Upon presentation of any Security of such series that is to be
redeemed in part only, the Company shall execute and the Trustee shall
authenticate and the office or agency where the Security is presented shall
deliver to the holder thereof, at the expense of the Company, a new Security of
the same series of authorized denominations in principal amount equal to the
unredeemed portion of the Security so presented.

      SECTION 3.04 SINKING FUND.

      The provisions of Sections 3.04, 3.05 and 3.06 shall be applicable to any
sinking fund for the retirement of Securities of a series, except as otherwise
specified as contemplated by Section 2.01 for Securities of such series.

      The minimum amount of any sinking fund payment provided for by the terms
of Securities of any series is herein referred to as a "mandatory sinking fund
payment," and any payment in excess of such minimum amount provided for by the
terms of Securities of any series is herein referred to as an "optional sinking
fund payment". If provided for by the terms of Securities of any series, the
cash amount of any sinking fund payment may be subject to reduction as provided
in Section 3.05. Each sinking fund payment shall be applied to the redemption of
Securities of any series as provided for by the terms of Securities of such
series.

      SECTION 3.05 SATISFACTION OF SINKING FUND PAYMENTS WITH SECURITIES.

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

      SECTION 3.06 REDEMPTION OF SECURITIES FOR SINKING FUND.

      Not less than 45 days prior to each sinking fund payment date for any
series of Securities (unless a shorter period shall be satisfactory to the
Trustee), the Company will deliver to the Trustee an Officers' Certificate
specifying the amount of the next ensuing sinking fund payment for that series
pursuant to the terms of the series, the portion thereof, if any, that is to be
satisfied by delivering and crediting Securities of that series pursuant to
Section 3.05 and the basis for such credit and will, together with such
Officers' Certificate, deliver to the Trustee any Securities to be so delivered.
Not less than 30 days before each such sinking fund payment date the Trustee
shall select the Securities to be redeemed upon such sinking fund payment date
in the manner specified in Section 3.02 and cause notice of the redemption
thereof to be given in the name of and at the expense of the Company in the
manner provided in Section 3.02. Such notice having been duly given, the
redemption of such Securities shall be made upon the terms and in the manner
stated in Section 3.03.

                                       16
<PAGE>

                                   ARTICLE 4

                                    COVENANTS

      SECTION 4.01 PAYMENT OF PRINCIPAL, PREMIUM AND INTEREST.

      The Company will duly and punctually pay or cause to be paid the principal
of (and premium, if any) and interest on the Securities of that series at the
time and place and in the manner provided herein and established with respect to
such Securities.

      SECTION 4.02 MAINTENANCE OF OFFICE OR AGENCY.

      So long as any series of the Securities remain Outstanding, the Company
agrees to maintain an office or agency in the Borough of Manhattan, the City and
State of New York, with respect to each such series and at such other location
or locations as may be designated as provided in this Section 4.02, where (i)
Securities of that series may be presented for payment, (ii) Securities of that
series may be presented as herein above authorized for registration of transfer
and exchange, and (iii) notices and demands to or upon the Company in respect of
the Securities of that series and this Indenture may be given or served, such
designation to continue with respect to such office or agency until the Company
shall, by written notice signed by any officer authorized to sign an Officers'
Certificate and delivered to the Trustee, designate some other office or agency
for such purposes or any of them. 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, notices and demands may be made or
served at the Corporate Trust Office of the Trustee, and the Company hereby
appoints the Trustee as its agent to receive all such presentations, notices and
demands. The Company initially appoints the Corporate Trust Office of the
Trustee located in the Borough of Manhattan, the City of New York as its paying
agent with respect to the Securities.

      SECTION 4.03 PAYING AGENTS.

            (a)   If the Company shall appoint one or more paying agents for all
or any series of the Securities, other than the Trustee, the Company will cause
each such paying agent to execute and deliver to the Trustee an instrument in
which such agent shall agree with the Trustee, subject to the provisions of this
Section:

                  (1)   that it will hold all sums held by it as such agent for
the payment of the principal of (and premium, if any) or interest on the
Securities of that series (whether such sums have been paid to it by the Company
or by any other obligor of such Securities) in trust for the benefit of the
Persons entitled thereto;

                  (2)   that it will give the Trustee notice of any failure by
the Company (or by any other obligor of such Securities) to make any payment of
the principal of (and premium, if any) or interest on the Securities of that
series when the same shall be due and payable;

                                       17
<PAGE>

                  (3)   that it will, at any time during the continuance of any
failure referred to in the preceding paragraph (a)(2) above, upon the written
request of the Trustee, forthwith pay to the Trustee all sums so held in trust
by such paying agent; and

                  (4)   that it will perform all other duties of paying agent as
set forth in this Indenture.

            (b)   If the Company shall act as its own paying agent with respect
to any series of the Securities, it will on or before each due date of the
principal of (and premium, if any) or interest on Securities of that series, set
aside, segregate and hold in trust for the benefit of the Persons entitled
thereto a sum sufficient to pay such principal (and premium, if any) or interest
so becoming due on Securities of that series until such sums shall be paid to
such Persons or otherwise disposed of as herein provided and will promptly
notify the Trustee of such action, or any failure (by it or any other obligor on
such Securities) to take such action. Whenever the Company shall have one or
more paying agents for any series of Securities, it will, prior to each due date
of the principal of (and premium, if any) or interest on any Securities of that
series, deposit with the paying agent a sum sufficient to pay the principal (and
premium, if any) or interest so becoming due, such sum to be held in trust for
the benefit of the Persons entitled to such principal, premium or interest, and
(unless such paying agent is the Trustee) the Company will promptly notify the
Trustee of this action or failure so to act.

            (c)   Notwithstanding anything in this Section to the contrary, (i)
the agreement to hold sums in trust as provided in this Section is subject to
the provisions of Section 11.05, and (ii) the Company may at any time, for the
purpose of obtaining the satisfaction and discharge of this Indenture or for any
other purpose, pay, or direct any paying agent to pay, to the Trustee all sums
held in trust by the Company or such paying agent, such sums to be held by the
Trustee upon the same terms and conditions as those upon which such sums were
held by the Company or such paying agent; and, upon such payment by the Company
or any paying agent to the Trustee, the Company or such paying agent shall be
released from all further liability with respect to such money.

      SECTION 4.04 APPOINTMENT TO FILL VACANCY IN OFFICE OF TRUSTEE.

      The Company, whenever necessary to avoid or fill a vacancy in the office
of Trustee, will appoint, in the manner provided in Section 7.10, a Trustee, so
that there shall at all times be a Trustee hereunder.

      SECTION 4.05 COMPLIANCE WITH CONSOLIDATION PROVISIONS.

      The Company will not, while any of the Securities remain Outstanding,
consolidate with or merge into any other Person, in either case where the
Company is not the survivor of such transaction, or sell or convey all or
substantially all of its property to any other Person unless the provisions of
Article Ten hereof are complied with.

                                   ARTICLE 5

                                       18
<PAGE>

              SECURITYHOLDERS' LISTS AND REPORTS BY THE COMPANY AND
                                  THE TRUSTEE

      SECTION 5.01 COMPANY TO FURNISH TRUSTEE NAMES AND ADDRESSES OF
SECURITYHOLDERS.

      The Company will furnish or cause to be furnished to the Trustee (a)
within 15 days after each regular record date (as defined in Section 2.03) a
list, in such form as the Trustee may reasonably require, of the names and
addresses of the holders of each series of Securities as of such regular record
date, provided that the Company shall not be obligated to furnish or cause to
furnish such list at any time that the list shall not differ in any respect from
the most recent list furnished to the Trustee by the Company and (b) at such
other times as the Trustee may request in writing within 30 days after the
receipt by the Company of any such request, a list of similar form and content
as of a date not more than 15 days prior to the time such list is furnished;
provided, however, that, in either case, no such list need be furnished for any
series for which the Trustee shall be the Security Registrar .

      SECTION 5.02 PRESERVATION OF INFORMATION; COMMUNICATIONS WITH
SECURITYHOLDERS.

            (a)   The Trustee shall preserve, in as current a form as is
reasonably practicable, all information as to the names and addresses of the
holders of Securities contained in the most recent list furnished to it as
provided in Section 5.01 and as to the names and addresses of holders of
Securities received by the Trustee in its capacity as Security Registrar (if
acting in such capacity).

            (b)   The Trustee may destroy any list furnished to it as provided
in Section 5.01 upon receipt of a new list so furnished.

            (c)   Securityholders may communicate as provided in Section 312(b)
of the Trust Indenture Act with other Securityholders with respect to their
rights under this Indenture or under the Securities, and, in connection with any
such communications, the Trustee shall satisfy its obligations under Section
312(b) of the Trust Indenture Act in accordance with the provisions of Section
312(b) of the Trust Indenture Act.

      SECTION 5.03 REPORTS BY THE COMPANY.

      The Company covenants and agrees to provide a copy to the Trustee, after
the Company is required to file the same with the Securities and Exchange
Commission, copies of the annual reports and of the information, documents and
other reports (or copies of such portions of any of the foregoing as the
Securities and Exchange Commission may from time to time by rules and
regulations prescribe) that the Company may be required to file with the
Securities and Exchange Commission pursuant to Section 13 or Section 15(d) of
the Exchange Act. The Company shall also comply with the requirements of Section
314 of the Trust Indenture Act, but only to the extent then applicable to the
Company.

                                       19
<PAGE>

      SECTION 5.04 REPORTS BY THE TRUSTEE.

            (a)   On or before July 1 in each year in which any of the
Securities are Outstanding, the Trustee shall transmit by mail, first class
postage prepaid, to the Securityholders, as their names and addresses appear
upon the Security Register, a brief report dated as of the preceding May 1, if
and to the extent required under Section 313(a) of the Trust Indenture Act.

            (b)   The Trustee shall comply with Section 313(b) and 313(c) of the
Trust Indenture Act.

            (c)   A copy of each such report shall, at the time of such
transmission to Securityholders, be filed by the Trustee with the Company, with
each securities exchange upon which any Securities are listed (if so listed) and
also with the Securities and Exchange Commission. The Company agrees to notify
the Trustee when any Securities become listed on any securities exchange.

                                   ARTICLE 6

             REMEDIES OF THE TRUSTEE AND SECURITYHOLDERS ON EVENT OF
                                     DEFAULT

      SECTION 6.01 EVENTS OF DEFAULT.

            (a)   Whenever used herein with respect to Securities of a
particular series, "Event of Default" means any one or more of the following
events that has occurred and is continuing:

                  (1)   the Company defaults in the payment of any installment
of interest upon any of the Securities of that series, as and when the same
shall become due and payable, and such default continues for a period of 90
days; provided, however, that a valid extension of an interest payment period by
the Company in accordance with the terms of any indenture supplemental hereto
shall not constitute a default in the payment of interest for this purpose;

                  (2)   the Company defaults in the payment of the principal of
(or premium, if any, on) any of the Securities of that series as and when the
same shall become due and payable whether at maturity, upon redemption, by
declaration or otherwise, or in any payment required by any sinking or analogous
fund established with respect to that series; provided, however, that a valid
extension of the maturity of such Securities in accordance with the terms of any
indenture supplemental hereto shall not constitute a default in the payment of
principal or premium, if any;

                  (3)   the Company fails to observe or perform any other of its
covenants or agreements with respect to that series contained in this Indenture
or otherwise established with respect to that series of Securities pursuant to
Section 2.01 hereof (other than a covenant or agreement that has been expressly
included in this Indenture solely for the benefit of one or more series of
Securities other than such series) for a period of 90 days after the date on
which written

                                       20
<PAGE>

notice of such failure, requiring the same to be remedied and stating that such
notice is a "Notice of Default" hereunder, shall have been given to the Company
by the Trustee, by registered or certified mail, or to the Company and the
Trustee by the holders of at least 25% in principal amount of the Securities of
that series at the time Outstanding;

                  (4)   the Company pursuant to or within the meaning of any
Bankruptcy Law (i) commences a voluntary case, (ii) consents to the entry of an
order for relief against it in an involuntary case, (iii) consents to the
appointment of a Custodian of it or for all or substantially all of its property
or (iv) makes a general assignment for the benefit of its creditors; or

                  (5)   a court of competent jurisdiction enters an order under
any Bankruptcy Law that (i) is for relief against the Company in an involuntary
case, (ii) appoints a Custodian of the Company for all or substantially all of
its property or (iii) orders the liquidation of the Company, and the order or
decree remains unstayed and in effect for 90 days.

            (b)   In each and every such case (other than an Event of Default
specified in clause (4) or clause (5) above), unless the principal of all the
Securities of that series shall have already become due and payable, either the
Trustee or the holders of not less than 25% in aggregate principal amount of the
Securities of that series then Outstanding hereunder, by notice in writing to
the Company (and to the Trustee if given by such Securityholders), may declare
the principal of (and premium, if any, on) and accrued and unpaid interest on
all the Securities of that series to be due and payable immediately, and upon
any such declaration the same shall become and shall be immediately due and
payable. If an Event of Default specified in clause (4) or clause (5) above
occurs, the principal of and accrued and unpaid interest on all the Securities
of that series shall automatically be immediately due and payable without any
declaration or other act on the part of the Trustee or the holders of the
Securities.

            (c)   At any time after the principal of (and premium, if any, on)
and accrued and unpaid interest on the Securities of that series shall have been
so declared due and payable, and before any judgment or decree for the payment
of the moneys due shall have been obtained or entered as hereinafter provided,
the holders of a majority in aggregate principal amount of the Securities of
that series then Outstanding hereunder, by written notice to the Company and the
Trustee, may rescind and annul such declaration and its consequences if: (i) the
Company has paid or deposited with the Trustee a sum sufficient to pay all
matured installments of interest upon all the Securities of that series and the
principal of (and premium, if any, on) any and all Securities of that series
that shall have become due otherwise than by acceleration (with interest upon
such principal and premium, if any, and, to the extent that such payment is
enforceable under applicable law, upon overdue installments of interest, at the
rate per annum expressed in the Securities of that series to the date of such
payment or deposit) and the amount payable to the Trustee under Section 7.06,
and (ii) any and all Events of Default under the Indenture with respect to such
series, other than the nonpayment of principal on (and premium, if any, on) and
accrued and unpaid interest on Securities of that series that shall not have
become due by their terms, shall have been remedied or waived as provided in
Section 6.06.

      No such rescission and annulment shall extend to or shall affect any
subsequent default or impair any right consequent thereon.

                                       21
<PAGE>

            (d)   In case the Trustee shall have proceeded to enforce any right
with respect to Securities of that series under this Indenture and such
proceedings shall have been discontinued or abandoned because of such rescission
or annulment or for any other reason or shall have been determined adversely to
the Trustee, then and in every such case, subject to any determination in such
proceedings, the Company and the Trustee shall be restored respectively to their
former positions and rights hereunder, and all rights, remedies and powers of
the Company and the Trustee shall continue as though no such proceedings had
been taken.

      SECTION 6.02 COLLECTION OF INDEBTEDNESS AND SUITS FOR ENFORCEMENT BY
TRUSTEE.

            (a)   The Company covenants that (i) in case it shall default in the
payment of any installment of interest on any of the Securities of a series, or
in any payment required by any sinking or analogous fund established with
respect to that series as and when the same shall have become due and payable,
and such default shall have continued for a period of 90 Business Days, or (ii)
in case it shall default in the payment of the principal of (or premium, if any,
on) any of the Securities of a series when the same shall have become due and
payable, whether upon maturity of the Securities of a series or upon redemption
or upon declaration or otherwise then, upon demand of the Trustee, the Company
will pay to the Trustee, for the benefit of the holders of the Securities of
that series, the whole amount that then shall have been become due and payable
on all such Securities for principal (and premium, if any) or interest, or both,
as the case may be, with interest upon the overdue principal (and premium, if
any) and (to the extent that payment of such interest is enforceable under
applicable law) upon overdue installments of interest at the rate per annum
expressed in the Securities of that series; and, in addition thereto, such
further amount as shall be sufficient to cover the costs and expenses of
collection, and the amount payable to the Trustee under Section 7.06.

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

            (c)   In case of any receivership, insolvency, liquidation,
bankruptcy, reorganization, readjustment, arrangement, composition or judicial
proceedings affecting the Company, or its creditors or property, the Trustee
shall have power to intervene in such proceedings and take any action therein
that may be permitted by the court and shall (except as may be otherwise
provided by law) be entitled to file such proofs of claim and other papers and
documents as may be necessary or advisable in order to have the claims of the
Trustee and of the holders of Securities of such series allowed for the entire
amount due and payable by the Company under the Indenture at the date of
institution of such proceedings and for any additional amount that may become
due and payable by the Company after such date, and to collect and receive any
moneys or other property payable or deliverable on any such claim, and to
distribute the same after the deduction of the amount payable to the Trustee
under Section 7.06; and any receiver, assignee or trustee in bankruptcy or
reorganization is hereby authorized by each of the

                                       22
<PAGE>

holders of Securities of such series to make such payments to the Trustee, and,
in the event that the Trustee shall consent to the making of such payments
directly to such Securityholders, to pay to the Trustee any amount due it under
Section 7.06.

            (d)   All rights of action and of asserting claims under this
Indenture, or under any of the terms established with respect to Securities of
that series, may be enforced by the Trustee without the possession of any of
such Securities, or the production thereof at any trial or other proceeding
relative thereto, and any such suit or proceeding instituted by the Trustee
shall be brought in its own name as trustee of an express trust, and any
recovery of judgment shall, after provision for payment to the Trustee of any
amounts due under Section 7.06, be for the ratable benefit of the holders of the
Securities of such series.

      In case of an Event of Default hereunder, the Trustee may in its
discretion proceed to protect and enforce the rights vested in it by this
Indenture by such appropriate judicial proceedings as the Trustee shall deem
most effectual to protect and enforce any of such rights, either at law or in
equity or in bankruptcy or otherwise, whether for the specific enforcement of
any covenant or agreement contained in the Indenture or in aid of the exercise
of any power granted in this Indenture, or to enforce any other legal or
equitable right vested in the Trustee by this Indenture or by law.

      Nothing contained herein shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Securityholder any
plan of reorganization, arrangement, adjustment or composition affecting the
Securities of that series or the rights of any holder thereof or to authorize
the Trustee to vote in respect of the claim of any Securityholder in any such
proceeding.

      SECTION 6.03 APPLICATION OF MONEYS OR PROPERTY COLLECTED.

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

      FIRST: To the payment of reasonable costs and expenses of collection and
of all amounts payable to the Trustee under Section 7.06;

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

      THIRD: To the payment of the remainder, if any, to the Company or any
other Person lawfully entitled thereto as requested by the Company.

                                       23
<PAGE>

      SECTION 6.04 LIMITATION ON SUITS.

      No holder of any Security of any series shall have any right by virtue or
by availing of any provision of this Indenture to institute any suit, action or
proceeding in equity or at law upon or under or with respect to this Indenture
or for the appointment of a receiver or trustee, or for any other remedy
hereunder, unless (i) such holder previously shall have given to the Trustee
written notice of an Event of Default and of the continuance thereof with
respect to the Securities of such series specifying such Event of Default, as
hereinbefore provided; (ii) the holders of not less than 25% in aggregate
principal amount of the Securities of such series then Outstanding shall have
made written request upon the Trustee to institute such action, suit or
proceeding in its own name as Trustee hereunder; (iii) such holder or holders
shall have offered to the Trustee such reasonable indemnity as it may require
against the costs, expenses and liabilities to be incurred therein or thereby;
(iv) the Trustee for 90 days after its receipt of such notice, request and offer
of indemnity, shall have failed to institute any such action, suit or proceeding
and (v) during such 90 day period, the holders of a majority in principal amount
of the Securities of that series do not give the Trustee a direction
inconsistent with the request.

      Notwithstanding anything contained herein to the contrary or any other
provisions of this Indenture, the right of any holder of any Security to receive
payment of the principal of (and premium, if any) and interest on such Security,
as therein provided, on or after the respective due dates expressed in such
Security (or in the case of redemption, on the redemption date), or to institute
suit for the enforcement of any such payment on or after such respective dates
or redemption date, shall not be impaired or affected without the consent of
such holder and by accepting a Security hereunder it is expressly understood,
intended and covenanted by the taker and holder of every Security of such series
with every other such taker and holder and the Trustee, that no one or more
holders of Securities of such series shall have any right in any manner
whatsoever by virtue or by availing of any provision of this Indenture to
affect, disturb or prejudice the rights of the holders of any other of such
Securities, or to obtain or seek to obtain priority over or preference to any
other such holder, or to enforce any right under this Indenture, except in the
manner herein provided and for the equal, ratable and common benefit of all
holders of Securities of such series. For the protection and enforcement of the
provisions of this Section, each and every Securityholder and the Trustee shall
be entitled to such relief as can be given either at law or in equity.

      SECTION 6.05 RIGHTS AND REMEDIES CUMULATIVE; DELAY OR OMISSION NOT WAIVER.

            (a)   Except as otherwise provided in Section 2.07, all powers and
remedies given by this Article to the Trustee or to the Securityholders shall,
to the extent permitted by law, be deemed cumulative and not exclusive of any
other powers and remedies available to the Trustee or the holders of the
Securities, by judicial proceedings or otherwise, to enforce the performance or
observance of the covenants and agreements contained in this Indenture or
otherwise established with respect to such Securities.

            (b)   No delay or omission of the Trustee or of any holder of any of
the Securities to exercise any right or power accruing upon any Event of Default
occurring and continuing as aforesaid shall impair any such right or power, or
shall be construed to be a waiver of any such default or an acquiescence
therein; and, subject to the provisions of Section 6.04,

                                       24
<PAGE>

every power and remedy given by this Article or by law to the Trustee or the
Securityholders may be exercised from time to time, and as often as shall be
deemed expedient, by the Trustee or by the Securityholders.

      SECTION 6.06 CONTROL BY SECURITYHOLDERS.

      The holders of a majority in aggregate principal amount of the Securities
of any series at the time Outstanding, determined in accordance with Section
8.04, shall have the right to direct the time, method and place of conducting
any proceeding for any remedy available to the Trustee, or exercising any trust
or power conferred on the Trustee with respect to such series; provided,
however, that such direction shall not be in conflict with any rule of law or
with this Indenture. Subject to the provisions of Section 7.01, the Trustee
shall have the right to decline to follow any such direction if the Trustee in
good faith shall, by a Responsible Officer or officers of the Trustee, determine
that the proceeding so directed, subject to the Trustee's duties under the Trust
Indenture Act, would involve the Trustee in personal liability or might be
unduly prejudicial to the Securityholders not involved in the proceeding. The
holders of a majority in aggregate principal amount of the Securities of any
series at the time Outstanding affected thereby, determined in accordance with
Section 8.04, may on behalf of the holders of all of the Securities of such
series waive any past default in the performance of any of the covenants
contained herein or established pursuant to Section 2.01 with respect to such
series and its consequences, except a default in the payment of the principal
of, or premium, if any, or interest on, any of the Securities of that series as
and when the same shall become due by the terms of such Securities otherwise
than by acceleration (unless such default has been cured and a sum sufficient to
pay all matured installments of interest and principal and any premium has been
deposited with the Trustee (in accordance with Section 6.01(c)). Upon any such
waiver, the default covered thereby shall be deemed to be cured for all purposes
of this Indenture and the Company, the Trustee and the holders of the Securities
of such series shall be restored to their former positions and rights hereunder,
respectively; but no such waiver shall extend to any subsequent or other default
or impair any right consequent thereon.

      SECTION 6.07 UNDERTAKING TO PAY COSTS.

      All parties to this Indenture agree, and each holder of any Securities by
such holder's acceptance thereof shall be deemed to have agreed, that any court
may in its discretion require, in any suit for the enforcement of any right or
remedy under this Indenture, or in any suit against the Trustee for any action
taken or omitted by it as Trustee, the filing by any party litigant in such suit
of an undertaking to pay the costs of such suit, and that such court may in its
discretion assess reasonable costs, including reasonable attorneys' fees,
against any party litigant in such suit, having due regard to the merits and
good faith of the claims or defenses made by such party litigant; but the
provisions of this Section shall not apply to any suit instituted by the
Trustee, to any suit instituted by any Securityholder, or group of
Securityholders, holding more than 10% in aggregate principal amount of the
Outstanding Securities of any series, or to any suit instituted by any
Securityholder for the enforcement of the payment of the principal of (or
premium, if any) or interest on any Security of such series, on or after the
respective due dates expressed in such Security or established pursuant to this
Indenture.

                                       25
<PAGE>

                                   ARTICLE 7

                             CONCERNING THE TRUSTEE

      SECTION 7.01 CERTAIN DUTIES AND RESPONSIBILITIES OF TRUSTEE.

            (a)   The Trustee, prior to the occurrence of an Event of Default
with respect to the Securities of a series and after the curing of all Events of
Default with respect to the Securities of that series that may have occurred,
shall undertake to perform with respect to the Securities of such series such
duties and only such duties as are specifically set forth in this Indenture, and
no implied covenants shall be read into this Indenture against the Trustee. In
case an Event of Default with respect to the Securities of a series has occurred
(that has not been cured or waived), the Trustee shall exercise with respect to
Securities of that series such of the rights and powers vested in it by this
Indenture, and use the same degree of care and skill in their exercise, as a
prudent man would exercise or use under the circumstances in the conduct of his
own affairs.

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

                  (i)   prior to the occurrence of an Event of Default with
respect to the Securities of a series and after the curing or waiving of all
such Events of Default with respect to that series that may have occurred:

                        (a)   the duties and obligations of the Trustee shall
with respect to the Securities of such series be determined solely by the
express provisions of this Indenture, and the Trustee shall not be liable with
respect to the Securities of such series except for the performance of such
duties and obligations as are specifically set forth in this Indenture, and no
implied covenants or obligations shall be read into this Indenture against the
Trustee; and

                        (b)   in the absence of bad faith on the part of the
Trustee, the Trustee may with respect to the Securities of such series
conclusively rely, as to the truth of the statements and the correctness of the
opinions expressed therein, upon any certificates or opinions furnished to the
Trustee and conforming to the requirements of this Indenture; but in the case of
any such certificates or opinions that by any provision hereof are specifically
required to be furnished to the Trustee, the Trustee shall be under a duty to
examine the same to determine whether or not they conform to the requirement of
this Indenture;

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

                  (iii) the Trustee shall not be liable with respect to any
action taken or omitted to be taken by it in good faith in accordance with the
direction of the holders of not less than a majority in principal amount of the
Securities of any series at the time Outstanding relating to the time, method
and place of conducting any proceeding for any remedy available to the

                                       26
<PAGE>

Trustee, or exercising any trust or power conferred upon the Trustee under this
Indenture with respect to the Securities of that series; and

                  (iv)  None of the provisions contained in this Indenture shall
require the Trustee to expend or risk its own funds or otherwise incur personal
financial liability in the performance of any of its duties or in the exercise
of any of its rights or powers if there is reasonable ground for believing that
the repayment of such funds or liability is not reasonably assured to it under
the terms of this Indenture or adequate indemnity against such risk is not
reasonably assured to it.

      SECTION 7.02 CERTAIN RIGHTS OF TRUSTEE.

      Except as otherwise provided in Section 7.01:

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

            (b)   Any request, direction, order or demand of the Company
mentioned herein shall be sufficiently evidenced by a Board Resolution or an
instrument signed in the name of the Company by any authorized officer of the
Company (unless other evidence in respect thereof is specifically prescribed
herein);

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

            (d)   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 Securityholders pursuant to the provisions of this
Indenture, unless such Securityholders shall have offered to the Trustee
reasonable security or indemnity against the costs, expenses and liabilities
that may be incurred therein or thereby; nothing contained herein shall,
however, relieve the Trustee of the obligation, upon the occurrence of an Event
of Default with respect to a series of the Securities (that has not been cured
or waived), to exercise with respect to Securities of that series such of the
rights and powers vested in it by this Indenture, and to use the same degree of
care and skill in their exercise, as a prudent man would exercise or use under
the circumstances in the conduct of his own affairs;

            (e)   The Trustee shall not be liable for any action taken or
omitted to be taken by it in good faith and believed by it to be authorized or
within the discretion or rights or powers conferred upon it by this Indenture;

            (f)   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, consent, order, approval, bond,
security, or other papers or documents, unless requested in writing so to do by
the holders of not less than a majority in principal amount of the

                                       27
<PAGE>

Outstanding Securities of the particular series affected thereby (determined as
provided in Section 8.04); provided, however, that if the payment within a
reasonable time to the Trustee of the costs, expenses or liabilities likely to
be incurred by it in the making of such investigation is, in the opinion of the
Trustee, not reasonably assured to the Trustee by the security afforded to it by
the terms of this Indenture, the Trustee may require reasonable indemnity
against such costs, expenses or liabilities as a condition to so proceeding. The
reasonable expense of every such examination shall be paid by the Company or, if
paid by the Trustee, shall be repaid by the Company upon demand; and

            (g)   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.

      In addition, the Trustee shall not be deemed to have knowledge of any
Default or Event of Default except (1) any Event of Default occurring pursuant
to Sections 6.01(a)(1), 6.01(a)(2) and 4.01 hereof or (2) any Default or Event
of Default of which the Trustee shall have received written notification in the
manner set forth in this Indenture or a Responsible Officer of the Trustee shall
have obtained actual knowledge. Delivery of reports, information and documents
to the Trustee under Section 5.03 is for informational purposes only and the
information and the Trustee's receipt of the foregoing shall not constitute
constructive notice of any information contained therein, or determinable from
information contained therein including the Company's compliance with any of
their covenants thereunder (as to which the Trustee is entitled to rely
conclusively on an Officers' Certificate).

      SECTION 7.03 TRUSTEE NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OR
SECURITIES.

            (a)   The recitals contained herein and in the Securities shall be
taken as the statements of the Company, and the Trustee assumes no
responsibility for the correctness of the same.

            (b)   The Trustee makes no representations as to the validity or
sufficiency of this Indenture or of the Securities.

            (c)   The Trustee shall not be accountable for the use or
application by the Company of any of the Securities or of the proceeds of such
Securities, or for the use or application of any moneys paid over by the Trustee
in accordance with any provision of this Indenture or established pursuant to
Section 2.01, or for the use or application of any moneys received by any paying
agent other than the Trustee.

      SECTION 7.04 MAY HOLD SECURITIES.

      The Trustee or any paying agent or Security Registrar, in its individual
or any other capacity, may become the owner or pledgee of Securities with the
same rights it would have if it were not Trustee, paying agent or Security
Registrar.

                                       28
<PAGE>

      SECTION 7.05 MONEYS HELD IN TRUST.

      Subject to the provisions of Section 11.05, all moneys received by the
Trustee shall, until used or applied as herein provided, be held in trust for
the purposes for which they were received, but need not be segregated from other
funds except to the extent required by law. The Trustee shall be under no
liability for interest on any moneys received by it hereunder except such as it
may agree with the Company to pay thereon.

      SECTION 7.06 COMPENSATION AND REIMBURSEMENT.

            (a)   The Company covenants and agrees to pay to the Trustee, and
the Trustee shall be entitled to, such reasonable compensation (which shall not
be limited by any provision of law in regard to the compensation of a trustee of
an express trust) as the Company and the Trustee may from time to time agree in
writing, for all services rendered by it in the execution of the trusts hereby
created and in the exercise and performance of any of the powers and duties
hereunder of the Trustee, and, except as otherwise expressly provided herein,
the Company will pay or reimburse the Trustee upon its request for all
reasonable expenses, disbursements and advances incurred or made by the Trustee
in accordance with any of the provisions of this Indenture (including the
reasonable compensation and the expenses and disbursements of its counsel and of
all Persons not regularly in its employ), except any such expense, disbursement
or advance as may arise from its negligence or bad faith and except as the
Company and Trustee may from time to time agree in writing. The Company also
covenants to indemnify the Trustee (and its officers, agents, directors and
employees) for, and to hold it harmless against, any loss, liability or expense
incurred without negligence or bad faith on the part of the Trustee and 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 of liability in the premises.

            (b)   The obligations of the Company under this Section to
compensate and indemnify the Trustee and to pay or reimburse the Trustee for
reasonable expenses, disbursements and advances shall constitute additional
indebtedness hereunder. Such additional indebtedness shall be secured by a lien
prior to that of the Securities upon all property and funds held or collected by
the Trustee as such, except funds held in trust for the benefit of the holders
of particular Securities.

      SECTION 7.07 RELIANCE ON OFFICERS' CERTIFICATE.

      Except as otherwise provided in Section 7.01, whenever in the
administration of the provisions of this Indenture the Trustee shall deem it
reasonably necessary or desirable that a matter be proved or established prior
to taking or suffering or omitting to take any action hereunder, such matter
(unless other evidence in respect thereof be herein specifically prescribed)
may, in the absence of negligence or bad faith on the part of the Trustee, be
deemed to be conclusively proved and established by an Officers' Certificate
delivered to the Trustee and such certificate, in the absence of negligence or
bad faith on the part of the Trustee, shall be full warrant to the Trustee for
any action taken, suffered or omitted to be taken by it under the provisions of
this Indenture upon the faith thereof.

                                       29
<PAGE>

      SECTION 7.08 DISQUALIFICATION; CONFLICTING INTERESTS.

      If the Trustee has or shall acquire any "conflicting interest" within the
meaning of Section 310(b) of the Trust Indenture Act, the Trustee and the
Company shall in all respects comply with the provisions of Section 310(b) of
the Trust Indenture Act.

      SECTION 7.09 CORPORATE TRUSTEE REQUIRED; ELIGIBILITY.

      There shall at all times be a Trustee with respect to the Securities
issued hereunder which shall at all times be a corporation organized and doing
business under the laws of the United States of America or any state or
territory thereof or of the District of Columbia, or a corporation or other
Person permitted to act as trustee by the Securities and Exchange Commission,
authorized under such laws to exercise corporate trust powers, having a combined
capital and surplus of at least fifty million U.S. dollars ($50,000,000), and
subject to supervision or examination by federal, state, territorial, or
District of Columbia authority.

      If such corporation or other Person publishes reports of condition at
least annually, pursuant to law or to the requirements of the aforesaid
supervising or examining authority, then for the purposes of this Section, the
combined capital and surplus of such corporation or other Person shall be deemed
to be its combined capital and surplus as set forth in its most recent report of
condition so published. The Company may not, nor may any Person directly or
indirectly controlling, controlled by, or under common control with the Company,
serve as Trustee. In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section, the Trustee shall resign
immediately in the manner and with the effect specified in Section 7.10.

      SECTION 7.10 RESIGNATION AND REMOVAL; APPOINTMENT OF SUCCESSOR.

            (a)   The Trustee or any successor hereafter appointed may at any
time resign with respect to the Securities of one or more series by giving
written notice thereof to the Company and by transmitting notice of resignation
by mail, first class postage prepaid, to the Securityholders of such series, as
their names and addresses appear upon the Security Register. Upon receiving such
notice of resignation, the Company shall promptly appoint a successor trustee
with respect to Securities of such series by written instrument, in duplicate,
executed by order of the Board of Directors, one copy of which instrument shall
be delivered to the resigning Trustee and one copy to the successor trustee. If
no successor trustee shall have been so appointed and have accepted appointment
within 30 days after the mailing of such notice of resignation, the resigning
Trustee may petition any court of competent jurisdiction for the appointment of
a successor trustee with respect to Securities of such series, or any
Securityholder of that series who has been a bona fide holder of a Security or
Securities for at least six months may on behalf of himself and all others
similarly situated, petition any such court for the appointment of a successor
trustee. Such court may thereupon after such notice, if any, as it may deem
proper and prescribe, appoint a successor trustee.

            (b)   In case at any time any one of the following shall occur:

                                       30
<PAGE>

                  (i)   the Trustee shall fail to comply with the provisions of
Section 7.08 after written request therefor by the Company or by any
Securityholder who has been a bona fide holder of a Security or Securities for
at least six months; or

                  (ii)  the Trustee shall cease to be eligible in accordance
with the provisions of Section 7.09 and shall fail to resign after written
request therefor by the Company or by any such Securityholder; or

                  (iii) the Trustee shall become incapable of acting, or shall
be adjudged a bankrupt or insolvent, or commence a voluntary bankruptcy
proceeding, or a receiver of the Trustee or of its property shall be appointed
or consented to, or any public officer shall take charge or control of the
Trustee or of its property or affairs for the purpose of rehabilitation,
conservation or liquidation;

      then, in any such case, the Company may remove the Trustee with respect to
all Securities and appoint a successor trustee by written instrument, in
duplicate, executed by order of the Board of Directors, one copy of which
instrument shall be delivered to the Trustee so removed and one copy to the
successor trustee, or any Securityholder who has been a bona fide holder of a
Security or Securities for at least six months may, on behalf of that holder and
all others similarly situated, petition any court of competent jurisdiction for
the removal of the Trustee and the appointment of a successor trustee. Such
court may thereupon after such notice, if any, as it may deem proper and
prescribe, remove the Trustee and appoint a successor trustee.

            (c)   The holders of a majority in aggregate principal amount of the
Securities of any series at the time Outstanding may at any time remove the
Trustee with respect to such series by so notifying the Trustee and the Company
and may appoint a successor Trustee for such series with the consent of the
Company.

            (d)   Any resignation or removal of the Trustee and appointment of a
successor trustee with respect to the Securities of a series pursuant to any of
the provisions of this Section shall become effective upon acceptance of
appointment by the successor trustee as provided in Section 7.11.

            (e)   Any successor trustee appointed pursuant to this Section may
be appointed with respect to the Securities of one or more series or all of such
series, and at any time there shall be only one Trustee with respect to the
Securities of any particular series.

      SECTION 7.11 ACCEPTANCE OF APPOINTMENT BY SUCCESSOR.

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

                                       31
<PAGE>
Trustee and shall duly assign, transfer and deliver to such successor trustee
all property and money held by such retiring Trustee hereunder.

            (b)   In case of the appointment hereunder of a successor trustee
with respect to the Securities of one or more (but not all) series, the Company,
the retiring Trustee and each successor trustee with respect to the Securities
of one or more series shall execute and deliver an indenture supplemental hereto
wherein each successor trustee shall accept such appointment and which (i) shall
contain such provisions as shall be necessary or desirable to transfer and
confirm to, and to vest in, each successor trustee all the rights, powers,
trusts and duties of the retiring Trustee with respect to the Securities of that
or those series to which the appointment of such successor trustee relates, (ii)
shall contain such provisions as shall be deemed necessary or desirable to
confirm that all the rights, powers, trusts and duties of the retiring Trustee
with respect to the Securities of that or those series as to which the retiring
Trustee is not retiring shall continue to be vested in the retiring Trustee, and
(iii) shall add to or change any of the provisions of this Indenture as shall be
necessary to provide for or facilitate the administration of the trusts
hereunder by more than one Trustee, it being understood that nothing herein or
in such supplemental indenture shall constitute such Trustees co-trustees of the
same trust, that each such Trustee shall be trustee of a trust or trusts
hereunder separate and apart from any trust or trusts hereunder administered by
any other such Trustee and that no Trustee shall be responsible for any act or
failure to act on the part of any other Trustee hereunder; and upon the
execution and delivery of such supplemental indenture the resignation or removal
of the retiring Trustee shall become effective to the extent provided therein,
such retiring Trustee shall with respect to the Securities of that or those
series to which the appointment of such successor trustee relates have no
further responsibility for the exercise of rights and powers or for the
performance of the duties and obligations vested in the Trustee under this
Indenture, and each such successor trustee, without any further act, deed or
conveyance, shall become vested with all the rights, powers, trusts and duties
of the retiring Trustee with respect to the Securities of that or those series
to which the appointment of such successor trustee relates; but, on request of
the Company or any successor trustee, such retiring Trustee shall duly assign,
transfer and deliver to such successor trustee, to the extent contemplated by
such supplemental indenture, the property and money held by such retiring
Trustee hereunder with respect to the Securities of that or those series to
which the appointment of such successor trustee relates.

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

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

            (e)   Upon acceptance of appointment by a successor trustee as
provided in this Section, the Company shall transmit notice of the succession of
such trustee hereunder by mail, first class postage prepaid, to the
Securityholders, as their names and addresses appear upon the Security Register.
If the Company fails to transmit such notice within ten days after acceptance of
appointment by the successor trustee, the successor trustee shall cause such
notice to be transmitted at the expense of the Company.

                                       32
<PAGE>

      SECTION 7.12 MERGER, CONVERSION, CONSOLIDATION OR SUCCESSION TO BUSINESS.

      Any corporation into which the Trustee may be merged or converted or with
which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to the corporate trust business of the Trustee, shall be
the successor of the Trustee hereunder, provided that such corporation shall be
qualified under the provisions of Section 7.08 and eligible under the provisions
of Section 7.09, without the execution or filing of any paper or any further act
on the part of any of the parties hereto, anything herein to the contrary
notwithstanding. In case any Securities shall have been authenticated, but not
delivered, by the Trustee then in office, any successor by merger, conversion or
consolidation to such authenticating Trustee may adopt such authentication and
deliver the Securities so authenticated with the same effect as if such
successor Trustee had itself authenticated such Securities.

      SECTION 7.13 PREFERENTIAL COLLECTION OF CLAIMS AGAINST THE COMPANY.

      The Trustee shall comply with Section 311(a) of the Trust Indenture Act,
excluding any creditor relationship described in Section 311(b) of the Trust
Indenture Act. A Trustee who has resigned or been removed shall be subject to
Section 311(a) of the Trust Indenture Act to the extent included therein.

      SECTION 7.14 NOTICE OF DEFAULT

      If any Default or any Event of Default occurs and is continuing and if
such Default or Event of Default is known to a Responsible Officer of the
Trustee, the Trustee shall mail to each Securityholder in the manner and to the
extent provided in Section 313(c) of the Trust Indenture Act notice of the
Default or Event of Default within 45 days after it occurs and becomes known to
the Trustee, unless such Default or Event of Default has been cured; provided,
however, that, except in the case of a default in the payment of the principal
of (or premium, if any) or interest on any Security, the Trustee shall be
protected in withholding such notice if and so long as the board of directors,
the executive committee or a trust committee of directors and/or Responsible
Officers of the Trustee in good faith determine that the withholding of such
notice is in the interest of the Securityholders.

                                    ARTICLE 8

                         CONCERNING THE SECURITYHOLDERS

      SECTION 8.01 EVIDENCE OF ACTION BY SECURITYHOLDERS.

      Whenever in this Indenture it is provided that the holders of a majority
or specified percentage in aggregate principal amount of the Securities of a
particular series may take any action (including the making of any demand or
request, the giving of any notice, consent or waiver or the taking of any other
action), the fact that at the time of taking any such action the holders of such
majority or specified percentage of that series have joined therein may be
evidenced by any instrument or any number of instruments of similar tenor
executed by such holders of Securities of that series in person or by agent or
proxy appointed in writing.

                                       33
<PAGE>

      If the Company shall solicit from the Securityholders of any series any
request, demand, authorization, direction, notice, consent, waiver or other
action, the Company may, at its option, as evidenced by an Officers'
Certificate, fix in advance a record date for such series for the determination
of Securityholders entitled to give such request, demand, authorization,
direction, notice, consent, waiver or other action, but the Company shall have
no obligation to do so. If such a record date is fixed, such request, demand,
authorization, direction, notice, consent, waiver or other action may be given
before or after the record date, but only the Securityholders of record at the
close of business on the record date shall be deemed to be Securityholders for
the purposes of determining whether Securityholders of the requisite proportion
of Outstanding Securities of that series have authorized or agreed or consented
to such request, demand, authorization, direction, notice, consent, waiver or
other action, and for that purpose the Outstanding Securities of that series
shall be computed as of the record date; provided, however, that no such
authorization, agreement or consent by such Securityholders on the 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.

      SECTION 8.02 PROOF OF EXECUTION BY SECURITYHOLDERS.

      Subject to the provisions of Section 7.01, proof of the execution of any
instrument by a Securityholder (such proof will not require notarization) or his
agent or proxy and proof of the holding by any Person of any of the Securities
shall be sufficient if made in the following manner:

            (a)   The fact and date of the execution by any such Person of any
instrument may be proved in any reasonable manner acceptable to the Trustee.

            (b)   The ownership of Securities shall be proved by the Security
Register of such Securities or by a certificate of the Security Registrar
thereof.

The Trustee may require such additional proof of any matter referred to in this
Section as it shall deem necessary.

      SECTION 8.03 WHO MAY BE DEEMED OWNERS.

      Prior to the due presentment for registration of transfer of any Security,
the Company, the Trustee, any paying agent and any Security Registrar may deem
and treat the Person in whose name such Security shall be registered upon the
books of the Company as the absolute owner of such Security (whether or not such
Security shall be overdue and notwithstanding any notice of ownership or writing
thereon made by anyone other than the Security Registrar) for the purpose of
receiving payment of or on account of the principal of, premium, if any, and
(subject to Section 2.03) interest on such Security and for all other purposes;
and neither the Company nor the Trustee nor any paying agent nor any Security
Registrar shall be affected by any notice to the contrary.

                                       34
<PAGE>

      SECTION 8.04 CERTAIN SECURITIES OWNED BY COMPANY DISREGARDED.

      In determining whether the holders of the requisite aggregate principal
amount of Securities of a particular series have concurred in any direction,
consent or waiver under this Indenture, the Securities of that series that are
owned by the Company or any other obligor on the Securities of that series or by
any Person directly or indirectly controlling or controlled by or under common
control with the Company or any other obligor on the Securities of that series
shall be disregarded and deemed not to be Outstanding for the purpose of any
such determination, except that for the purpose of determining whether the
Trustee shall be protected in relying on any such direction, consent or waiver,
only Securities of such series that the Trustee actually knows are so owned
shall be so disregarded. The Securities so owned that have been pledged in good
faith may be regarded as Outstanding for the purposes of this Section, if the
pledgee shall establish to the satisfaction of the Trustee the pledgee's right
so to act with respect to such Securities and that the pledgee is not a Person
directly or indirectly controlling or controlled by or under direct or indirect
common control with the Company or any such other obligor. In case of a dispute
as to such right, any decision by the Trustee taken upon the advice of counsel
shall be full protection to the Trustee.

      SECTION 8.05 ACTIONS BINDING ON FUTURE SECURITYHOLDERS.

      At any time prior to (but not after) the evidencing to the Trustee, as
provided in Section 8.01, of the taking of any action by the holders of the
majority or percentage in aggregate principal amount of the Securities of a
particular series specified in this Indenture in connection with such action,
any holder of a Security of that series that is shown by the evidence to be
included in the Securities the holders of which have consented to such action
may, by filing written notice with the Trustee, and upon proof of holding as
provided in Section 8.02, revoke such action so far as concerns such Security.
Except as aforesaid any such action taken by the holder of any Security shall be
conclusive and binding upon such holder and upon all future holders and owners
of such Security, and of any Security issued in exchange therefor, on
registration of transfer thereof or in place thereof, irrespective of whether or
not any notation in regard thereto is made upon such Security. Any action taken
by the holders of the majority or percentage in aggregate principal amount of
the Securities of a particular series specified in this Indenture in connection
with such action shall be conclusively binding upon the Company, the Trustee and
the holders of all the Securities of that series.

                                   ARTICLE 9

                             SUPPLEMENTAL INDENTURES

      SECTION 9.01 SUPPLEMENTAL INDENTURES WITHOUT THE CONSENT OF
SECURITYHOLDERS.

      In addition to any supplemental indenture otherwise authorized by this
Indenture, the Company and the Trustee may from time to time and at any time
enter into an indenture or indentures supplemental hereto (which shall conform
to the provisions of the Trust Indenture Act as then in effect), without the
consent of the Securityholders, for one or more of the following purposes:

                                       35
<PAGE>

            (a)   to cure any ambiguity, defect, or inconsistency herein or in
the Securities of any series;

            (b)   to comply with Article Ten;

            (c)   to provide for uncertificated Securities in addition to or in
place of certificated Securities;

            (d)   to add to the covenants, restrictions, conditions or
provisions relating to the Company for the benefit of the holders of all or any
series of Securities (and if such covenants, restrictions, conditions or
provisions are to be for the benefit of less than all series of Securities,
stating that such covenants, restrictions, conditions or provisions are
expressly being included solely for the benefit of such series), to make the
occurrence, or the occurrence and the continuance, of a default in any such
additional covenants, restrictions, conditions or provisions an Event of
Default, or to surrender any right or power herein conferred upon the Company;

            (e)   to add to, delete from, or revise the conditions, limitations,
and restrictions on the authorized amount, terms, or purposes of issue,
authentication, and delivery of Securities, as herein set forth;

            (f)   to make any change that does not adversely affect the rights
of any Securityholder in any material respect;

            (g)   to provide for the issuance of and establish the form and
terms and conditions of the Securities of any series as provided in Section
2.01, to establish the form of any certifications required to be furnished
pursuant to the terms of this Indenture or any series of Securities, or to add
to the rights of the holders of any series of Securities;

            (h)   to evidence and provide for the acceptance of appointment
hereunder by a successor trustee; or

            (i)   to comply with any requirements of the Securities and Exchange
Commission or any successor in connection with the qualification of this
Indenture under the Trust Indenture Act.

      The Trustee is hereby authorized to join with the Company in the execution
of any such supplemental indenture, and to make any further appropriate
agreements and stipulations that may be therein contained, but the Trustee shall
not be obligated to enter into any such supplemental indenture that affects the
Trustee's own rights, duties or immunities under this Indenture or otherwise.

      Any supplemental indenture authorized by the provisions of this Section
may be executed by the Company and the Trustee without the consent of the
holders of any of the Securities at the time Outstanding, notwithstanding any of
the provisions of Section 9.02.

                                       36
<PAGE>

      SECTION 9.02 SUPPLEMENTAL INDENTURES WITH CONSENT OF SECURITYHOLDERS.

      With the consent (evidenced as provided in Section 8.01) of the holders of
not less than a majority in aggregate principal amount of the Securities of each
series affected by such supplemental indenture or indentures at the time
Outstanding, the Company, when authorized by a Board Resolution, and the Trustee
may from time to time and at any time enter into an indenture or indentures
supplemental hereto (which shall conform to the provisions of the Trust
Indenture Act as then in effect) for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Indenture or
of any supplemental indenture or of modifying in any manner not covered by
Section 9.01 the rights of the holders of the Securities of such series under
this Indenture; provided, however, that no such supplemental indenture shall,
without the consent of the holders of each Security then Outstanding and
affected thereby, (a) extend the fixed maturity of any Securities of any series,
or reduce the principal amount thereof, or reduce the rate or extend the time of
payment of interest thereon, or reduce any premium payable upon the redemption
thereof or (b) reduce the aforesaid percentage of Securities, the holders of
which are required to consent to any such supplemental indenture.

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

      SECTION 9.03 EFFECT OF SUPPLEMENTAL INDENTURES.

      Upon the execution of any supplemental indenture pursuant to the
provisions of this Article or of Section 10.01, this Indenture shall, with
respect to such series, be and be deemed to be modified and amended in
accordance therewith and the respective rights, limitations of rights,
obligations, duties and immunities under this Indenture of the Trustee, the
Company and the holders of Securities of the series affected thereby shall
thereafter be determined, exercised and enforced hereunder subject in all
respects to such modifications and amendments, and all the terms and conditions
of any such supplemental indenture shall be and be deemed to be part of the
terms and conditions of this Indenture for any and all purposes.

      SECTION 9.04 SECURITIES AFFECTED BY SUPPLEMENTAL INDENTURES.

      Securities of any series affected by a supplemental indenture,
authenticated and delivered after the execution of such supplemental indenture
pursuant to the provisions of this Article or of Section 10.01, may bear a
notation in form approved by the Company, provided such form meets the
requirements of any securities exchange upon which such series may be listed, as
to any matter provided for in such supplemental indenture. If the Company shall
so determine, new Securities of that series so modified as to conform, in the
opinion of the Board of Directors, to any modification of this Indenture
contained in any such supplemental indenture may be prepared by the Company,
authenticated by the Trustee and delivered in exchange for the Securities of
that series then Outstanding.

                                       37
<PAGE>

      SECTION 9.05 EXECUTION OF SUPPLEMENTAL INDENTURES.

      Upon the request of the Company, accompanied by its Board Resolutions
authorizing the execution of any such supplemental indenture, and upon the
filing with the Trustee of evidence of the consent of Securityholders required
to consent thereto as aforesaid, the Trustee shall join with the Company in the
execution of such supplemental indenture unless such supplemental indenture
affects the Trustee's own rights, duties or immunities under this Indenture or
otherwise, in which case the Trustee may in its discretion but shall not be
obligated to enter into such supplemental indenture. The Trustee, subject to the
provisions of Section 7.01, will be entitled to receive and will be fully
protected in relying upon an Officers' Certificate and an Opinion of Counsel
stating that any supplemental indenture executed pursuant to this Article is
authorized or permitted by, and conforms to, the terms of this Article and that
it is proper for the Trustee under the provisions of this Article to join in the
execution thereof; provided, however, that such Officers' Certificate or Opinion
of Counsel need not be provided in connection with the execution of a
supplemental indenture that establishes the terms of a series of Securities
pursuant to Section 2.01 hereof.

      Promptly after the execution by the Company and the Trustee of any
supplemental indenture pursuant to the provisions of this Section, the Trustee
shall transmit by mail, first class postage prepaid, a notice, setting forth in
general terms the substance of such supplemental indenture, to the
Securityholders of all series affected thereby as their names and addresses
appear upon the Security Register. Any failure of the Trustee to mail such
notice, or any defect therein, shall not, however, in any way impair or affect
the validity of any such supplemental indenture.

                                   ARTICLE 10

                                SUCCESSOR ENTITY

      SECTION 10.01 COMPANY MAY CONSOLIDATE, ETC.

      Except as provided pursuant to Section 2.01 pursuant to a Board
Resolution, and set forth in an Officers' Certificate, or established in one or
more indentures supplemental to this Indenture, nothing contained in this
Indenture shall prevent any consolidation or merger of the Company with or into
any other Person (whether or not affiliated with the Company) or successive
consolidations or mergers in which the Company or its successor or successors
shall be a party or parties, or shall prevent any sale, conveyance, transfer or
other disposition of the property of the Company or its successor or successors
as an entirety, or substantially as an entirety, to any other corporation
(whether or not affiliated with the Company or its successor or successors)
authorized to acquire and operate the same; provided, however, the Company
hereby covenants and agrees that, upon any such consolidation or merger (in each
case, if the Company is not the survivor of such transaction), sale, conveyance,
transfer or other disposition, the due and punctual payment of the principal of
(premium, if any) and interest on all of the Securities of all series in
accordance with the terms of each series, according to their tenor, and the due
and punctual performance and observance of all the covenants and conditions of
this Indenture with respect to each series or established with respect to such
series pursuant to Section 2.01 to be kept or performed by the Company shall be
expressly assumed, by supplemental indenture

                                       38
<PAGE>

(which shall conform to the provisions of the Trust Indenture Act, as then in
effect) reasonably satisfactory in form to the Trustee executed and delivered to
the Trustee by the entity formed by such consolidation, or into which the
Company shall have been merged, or by the entity which shall have acquired such
property.

      SECTION 10.02 SUCCESSOR ENTITY SUBSTITUTED.

            (a)   In case of any such consolidation, merger, sale, conveyance,
transfer or other disposition and upon the assumption by the successor entity by
supplemental indenture, executed and delivered to the Trustee and satisfactory
in form to the Trustee, of the obligations set forth under Section 10.01 on all
of the Securities of all series Outstanding, such successor entity shall succeed
to and be substituted for the Company with the same effect as if it had been
named as the Company herein, and thereupon the predecessor corporation shall be
relieved of all obligations and covenants under this Indenture and the
Securities.

            (b)   In case of any such consolidation, merger, sale, conveyance,
transfer or other disposition, such changes in phraseology and form (but not in
substance) may be made in the Securities thereafter to be issued as may be
appropriate.

            (c)   Nothing contained in this Article shall require any action by
the Company in the case of a consolidation or merger of any Person into the
Company where the Company is the survivor of such transaction, or the
acquisition by the Company, by purchase or otherwise, of all or any part of the
property of any other Person (whether or not affiliated with the Company).

      SECTION 10.03 EVIDENCE OF CONSOLIDATION, ETC. TO TRUSTEE.

      The Trustee, subject to the provisions of Section 7.01, may receive an
Officers' Certificate or an Opinion of Counsel as conclusive evidence that any
such consolidation, merger, sale, conveyance, transfer or other disposition, and
any such assumption, comply with the provisions of this Article.

                                   ARTICLE 11

                           SATISFACTION AND DISCHARGE

      SECTION 11.01 SATISFACTION AND DISCHARGE OF INDENTURE.

      If at any time: (a) the Company shall have delivered to the Trustee for
cancellation all Securities of a series theretofore authenticated and not
delivered to the Trustee for cancellation (other than any Securities that shall
have been destroyed, lost or stolen and that shall have been replaced or paid as
provided in Section 2.07 and Securities for whose payment money or Governmental
Obligations have theretofore been deposited in trust or segregated and held in
trust by the Company and thereupon repaid to the Company or discharged from such
trust, as provided in Section 11.05); or (b) all such Securities of a particular
series not theretofore delivered to the Trustee for cancellation shall have
become due and payable, or are by their terms to become due and payable within
one year or are to be called for redemption within one year under arrangements
satisfactory to the Trustee for the giving of notice of redemption, and the
Company

                                       39
<PAGE>

shall deposit or cause to be deposited with the Trustee as trust funds the
entire amount in moneys or Governmental Obligations or a combination thereof,
sufficient in the opinion of a nationally recognized firm of independent public
accountants expressed in a written certification thereof delivered to the
Trustee, to pay at maturity or upon redemption all Securities of that series not
theretofore delivered to the Trustee for cancellation, including principal (and
premium, if any) and interest due or to become due to such date of maturity or
date fixed for redemption, as the case may be, and if the Company shall also pay
or cause to be paid all other sums payable hereunder with respect to such series
by the Company then this Indenture shall thereupon cease to be of further effect
with respect to such series except for the provisions of Sections 2.03, 2.05,
2.07, 4.01, 4.02, 4.03 and 7.10, that shall survive until the date of maturity
or redemption date, as the case may be, and Sections 7.06 and 11.05, that shall
survive to such date and thereafter, and the Trustee, on demand of the Company
and at the cost and expense of the Company shall execute proper instruments
acknowledging satisfaction of and discharging this Indenture with respect to
such series.

      SECTION 11.02 DISCHARGE OF OBLIGATIONS.

      If at any time all such Securities of a particular series not heretofore
delivered to the Trustee for cancellation or that have not become due and
payable as described in Section 11.01 shall have been paid by the Company by
depositing irrevocably with the Trustee as trust funds moneys or an amount of
Governmental Obligations sufficient to pay at maturity or upon redemption all
such Securities of that series not theretofore delivered to the Trustee for
cancellation, including principal (and premium, if any) and interest due or to
become due to such date of maturity or date fixed for redemption, as the case
may be, and if the Company shall also pay or cause to be paid all other sums
payable hereunder by the Company with respect to such series, then after the
date such moneys or Governmental Obligations, as the case may be, are deposited
with the Trustee the obligations of the Company under this Indenture with
respect to such series shall cease to be of further effect except for the
provisions of Sections 2.03, 2.05, 2.07, 4,01, 4.02, 4,03, 7.06, 7.10 and 11.05
hereof that shall survive until such Securities shall mature and be paid.

      Thereafter, Sections 7.06 and 11.05 shall survive.

      SECTION 11.03 DEPOSITED MONEYS TO BE HELD IN TRUST.

      All moneys or Governmental Obligations deposited with the Trustee pursuant
to Sections 11.01 or 11.02 shall be held in trust and shall be available for
payment as due, either directly or through any paying agent (including the
Company acting as its own paying agent), to the holders of the particular series
of Securities for the payment or redemption of which such moneys or Governmental
Obligations have been deposited with the Trustee.

      SECTION 11.04 PAYMENT OF MONEYS HELD BY PAYING AGENTS.

      In connection with the satisfaction and discharge of this Indenture all
moneys or Governmental Obligations then held by any paying agent under the
provisions of this Indenture shall, upon demand of the Company, be paid to the
Trustee and thereupon such paying agent

                                       40
<PAGE>

shall be released from all further liability with respect to such moneys or
Governmental Obligations.

      SECTION 11.05 REPAYMENT TO COMPANY.

      Any moneys or Governmental Obligations deposited with any paying agent or
the Trustee, or then held by the Company, in trust for payment of principal of
or premium, if any, or interest on the Securities of a particular series that
are not applied but remain unclaimed by the holders of such Securities for at
least two years after the date upon which the principal of (and premium, if any)
or interest on such Securities shall have respectively become due and payable,
or such other shorter period set forth in applicable escheat or abandoned or
unclaimed property law, shall be repaid to the Company on May 31 of each year or
upon the Company's request or (if then held by the Company) shall be discharged
from such trust; and thereupon the paying agent and the Trustee shall be
released from all further liability with respect to such moneys or Governmental
Obligations, and the holder of any of the Securities entitled to receive such
payment shall thereafter, as a general creditor, look only to the Company for
the payment thereof.

                                   ARTICLE 12

              IMMUNITY OF INCORPORATORS, STOCKHOLDERS, OFFICERS AND
                                   DIRECTORS

      SECTION 12.01 NO RECOURSE.

      No recourse under or upon any obligation, covenant or agreement of this
Indenture, or of any Security, or for any claim based thereon or otherwise in
respect thereof, shall be had against any incorporator, stockholder, officer or
director, past, present or future as such, of the Company or of any predecessor
or successor corporation, either directly or through the Company or any such
predecessor or successor corporation, whether by virtue of any constitution,
statute or rule of law, or by the enforcement of any assessment or penalty or
otherwise; it being expressly understood that this Indenture and the obligations
issued hereunder are solely corporate obligations, and that no such personal
liability whatever shall attach to, or is or shall be incurred by, the
incorporators, stockholders, officers or directors as such, of the Company or of
any predecessor or successor corporation, or any of them, because of the
creation of the indebtedness hereby authorized, or under or by reason of the
obligations, covenants or agreements contained in this Indenture or in any of
the Securities or implied therefrom; and that any and all such personal
liability of every name and nature, either at common law or in equity or by
constitution or statute, of, and any and all such rights and claims against,
every such incorporator, stockholder, officer or director as such, because of
the creation of the indebtedness hereby authorized, or under or by reason of the
obligations, covenants or agreements contained in this Indenture or in any of
the Securities or implied therefrom, are hereby expressly waived and released as
a condition of, and as a consideration for, the execution of this Indenture and
the issuance of such Securities.

                                       41
<PAGE>

                                   ARTICLE 13

                            MISCELLANEOUS PROVISIONS

      SECTION 13.01 EFFECT ON SUCCESSORS AND ASSIGNS.

      All the covenants, stipulations, promises and agreements in this Indenture
made by or on behalf of the Company shall bind its successors and assigns,
whether so expressed or not.

      SECTION 13.02 ACTIONS BY SUCCESSOR.

      Any act or proceeding by any provision of this Indenture authorized or
required to be done or performed by any board, committee or officer of the
Company shall and may be done and performed with like force and effect by the
corresponding board, committee or officer of any corporation that shall at the
time be the lawful successor of the Company.

      SECTION 13.03 SURRENDER OF COMPANY POWERS.

      The Company by instrument in writing executed by authority of its Board of
Directors and delivered to the Trustee may surrender any of the powers reserved
to the Company, and thereupon such power so surrendered shall terminate both as
to the Company and as to any successor corporation.

      SECTION 13.04 NOTICES.

      Except as otherwise expressly provided herein, any notice, request or
demand that by any provision of this Indenture is required or permitted to be
given, made or served by the Trustee or by the holders of Securities or by any
other Person pursuant to this Indenture to or on the Company may be given or
served by being deposited in first class mail, postage prepaid, addressed (until
another address is filed in writing by the Company with the Trustee), as
follows: 2100 Powell Street, Emeryville, CA 94608. Any notice, election, request
or demand by the Company or any Securityholder or by any other Person pursuant
to this Indenture to or upon the Trustee shall be deemed to have been
sufficiently given or made, for all purposes, if given or made in writing at the
Corporate Trust Office of the Trustee.

      SECTION 13.05 GOVERNING LAW.

      This Indenture and each Security shall be deemed to be a contract made
under the internal laws of the State of New York, and for all purposes shall be
construed in accordance with the laws of said State, except to the extent that
the Trust Indenture Act is applicable.

      SECTION 13.06 TREATMENT OF SECURITIES AS DEBT.

      It is intended that the Securities will be treated as indebtedness and not
as equity for federal income tax purposes. The provisions of this Indenture
shall be interpreted to further this intention.

                                       42
<PAGE>

      SECTION 13.07 CERTIFICATES AND OPINIONS AS TO CONDITIONS PRECEDENT.

            (a)   Upon any application or demand by the Company to the Trustee
to take any action under any of the provisions of this Indenture, the Company
shall furnish to the Trustee an Officers' Certificate stating that all
conditions precedent provided for in this Indenture (other than the certificate
to be delivered pursuant to Section 13.12) relating to the proposed action have
been complied with and an Opinion of Counsel stating that in the opinion of such
counsel all such conditions precedent have been complied with, except that in
the case of any such application or demand as to which the furnishing of such
documents is specifically required by any provision of this Indenture relating
to such particular application or demand, no additional certificate or opinion
need be furnished.

            (b)   Each certificate or opinion provided for in this Indenture and
delivered to the Trustee with respect to compliance with a condition or covenant
in this Indenture shall include (i) a statement that the Person making such
certificate or opinion has read such covenant or condition; (ii) a brief
statement as to the nature and scope of the examination or investigation upon
which the statements or opinions contained in such certificate or opinion are
based; (iii) a statement that, in the opinion of such Person, he has made such
examination or investigation as is reasonably necessary to enable him to express
an informed opinion as to whether or not such covenant or condition has been
complied with; and (iv) a statement as to whether or not, in the opinion of such
Person, such condition or covenant has been complied with.

      SECTION 13.08 PAYMENTS ON BUSINESS DAYS.

      Except as provided pursuant to Section 2.01 pursuant to a Board
Resolution, and set forth in an Officers' Certificate, or established in one or
more indentures supplemental to this Indenture, in any case where the date of
maturity of interest or principal of any Security or the date of redemption of
any Security shall not be a Business Day, then payment of interest or principal
(and premium, if any) may be made on the next succeeding Business Day with the
same force and effect as if made on the nominal date of maturity or redemption,
and no interest shall accrue for the period after such nominal date.

      SECTION 13.09 CONFLICT WITH TRUST INDENTURE ACT.

      If and to the extent that any provision of this Indenture limits,
qualifies or conflicts with the duties imposed by Sections 310 to 317,
inclusive, of the Trust Indenture Act, such imposed duties shall control.

      SECTION 13.10 COUNTERPARTS.

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

      SECTION 13.11 SEPARABILITY.

      In case any one or more of the provisions contained in this Indenture or
in the Securities of any series shall for any reason be held to be invalid,
illegal or unenforceable in any respect,

                                       43
<PAGE>

such invalidity, illegality or unenforceability shall not affect any other
provisions of this Indenture or of such Securities, but this Indenture and such
Securities shall be construed as if such invalid or illegal or unenforceable
provision had never been contained herein or therein.

      SECTION 13.12 COMPLIANCE CERTIFICATES.

      The Company shall deliver to the Trustee, within 120 days after the end of
each fiscal year during which any Securities of any series were outstanding, a
compliance certificate stating whether or not the signer knows of any Default or
Event of Default that occurred during such fiscal year. Such certificate shall
contain a certification from the principal executive officer, principal
financial officer or principal accounting officer of the Company that a review
has been conducted of the activities of the Company and the Company's
performance under this Indenture and that the Company has complied with all
conditions and covenants under this Indenture. For purposes of this Section
13.12, such compliance shall be determined without regard to any period of grace
or requirement of notice provided under this Indenture. If the officer of the
Company signing such certificate has knowledge of such a Default or Event of
Default, the certificate shall describe any such Default or Event of Default and
its status.

                                       44
<PAGE>

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

                                           ONYX PHARMACEUTICALS, INC.

                                           By: _______________________________

                                           Name: _____________________________

                                           Title: ____________________________

                                           WELLS FARGO BANK, N.A., as Trustee

                                           By: _______________________________

                                           Name: _____________________________

                                           Title: ____________________________

                                       45
<PAGE>

CROSS-REFERENCE TABLE (1)

<TABLE>
<CAPTION>
SECTION OF TRUST INDENTURE ACT OF 1939, AS AMENDED                                SECTION OF INDENTURE
--------------------------------------------------                                --------------------
<S>                                                                               <C>
310(a)                                                                                7.09
310(b)                                                                                7.08
                                                                                      7.10
310(c)                                                                                Inapplicable
311(a)                                                                                7.13
311(b)                                                                                7.13
311(c)                                                                                Inapplicable
312(a)                                                                                5.01
                                                                                      5.02(a)
312(b)                                                                                5.02(c)
312(c)                                                                                5.02(c)
313(a)                                                                                5.04(a)
313(b)                                                                                5.04(b)
313(c)                                                                                5.04(a)
                                                                                      5.04(b)
313(d)                                                                                5.04(c)
314(a)                                                                                5.03
                                                                                      13.12
314(b)                                                                                Inapplicable
314(c)                                                                                13.07(a)
314(d)                                                                                Inapplicable
314(e)                                                                                13.07(b)
314(f)                                                                                Inapplicable
315(a)                                                                                7.01(a)
                                                                                      7.01(b)
315(b)                                                                                7.14
315(c)                                                                                7.01
315(d)                                                                                7.01(b)
315(e)                                                                                6.07
316(a)                                                                                6.06
                                                                                      8.04
316(b)                                                                                6.04
316(c)                                                                                8.01
317(a)                                                                                6.02
317(b)                                                                                4.03
318(a)                                                                                13.09
</TABLE>

-----------------
(1)   This Cross-Reference Table does not constitute part of the Indenture and
shall not have any bearing on the interpretation of any of its terms or
provisions.

                                       46