Document:

<PAGE>

                                                                     EXHIBIT 4.1

                            NPS PHARMACEUTICALS, INC.

                                       AND

                         U.S. BANK NATIONAL ASSOCIATION

                                   AS TRUSTEE

                                    INDENTURE

                          DATED AS OF ___________, 200_

                             SENIOR DEBT SECURITIES

<PAGE>

                                TABLE OF CONTENTS

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ARTICLE 1 DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION ........................................   1

     Section 1.1   Definitions ...........................................................................   1
     Section 1.2   Compliance Certificates and Opinions ..................................................   8
     Section 1.3   Form of Documents Delivered to Trustee ................................................   9
     Section 1.4   Acts of Holders; Record Dates .........................................................   9
     Section 1.5   Notices, etc. to Trustee and Company ..................................................  11
     Section 1.6   Notice to Holders; Waiver .............................................................  12
     Section 1.7   Conflict with Trust Indenture Act .....................................................  12
     Section 1.8   Effect of Headings and Table of Contents ..............................................  12
     Section 1.9   Successors and Assigns ................................................................  12
     Section 1.10  Separability Clause ...................................................................  12
     Section 1.11  Benefits of Indenture .................................................................  13
     Section 1.12  Governing Law .........................................................................  13
     Section 1.13  Legal Holidays ........................................................................  13
     Section 1.14  Indenture and Securities Solely Corporate Obligations .................................  13
     Section 1.15  Indenture May be Executed in Counterparts .............................................  13

ARTICLE 2 SECURITY FORMS .................................................................................  14

     Section 2.1   Forms Generally .......................................................................  14
     Section 2.2   Form of Face of Security ..............................................................  14
     Section 2.3   Form of Reverse of Security ...........................................................  16
     Section 2.4   Form of Legend for Global Securities ..................................................  20
     Section 2.5   Form of Trustee's Certificate of Authentication .......................................  21
     Section 2.6   Form of Conversion Notice .............................................................  21

ARTICLE 3 THE SECURITIES .................................................................................  23

     Section 3.1   Amount Unlimited; Issuable in Series ..................................................  23
     Section 3.2   Denominations .........................................................................  26
     Section 3.3   Execution, Authentication, Delivery and Dating ........................................  26
     Section 3.4   Temporary Securities ..................................................................  27
     Section 3.5   Registration; Registration of Transfer and Exchange ...................................  28
     Section 3.6   Mutilated, Destroyed, Lost and Stolen Securities ......................................  29
     Section 3.7   Payment of Interest; Interest Rights Preserved ........................................  30
     Section 3.8   Persons Deemed Owners .................................................................  31
     Section 3.9   Cancellation ..........................................................................  32
     Section 3.10  Computation of Interest ...............................................................  32

ARTICLE 4 SATISFACTION AND DISCHARGE .....................................................................  32

     Section 4.1   Satisfaction and Discharge of Indenture ...............................................  32
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                               TABLE OF CONTENTS
                                  (continued)

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     Section 4.2   Application of Trust Money ...........................................................   33

ARTICLE 5 REMEDIES ......................................................................................   33

     Section 5.1   Events of Default ....................................................................   33
     Section 5.2   Acceleration of Maturity; Rescission and Annulment ...................................   35
     Section 5.3   Collection of Indebtedness and Suits for Enforcement by Trustee ......................   36
     Section 5.4   Trustee May File Proofs of Claim .....................................................   36
     Section 5.5   Trustee May Enforce Claims Without Possession of Securities ..........................   37
     Section 5.6   Application of Money Collected .......................................................   37
     Section 5.7   Limitation on Suits ..................................................................   37
     Section 5.8   Unconditional Right of Holders to Receive Principal, Premium and Interest
                    and to Convert ......................................................................   38
     Section 5.9   Restoration of Rights and Remedies ...................................................   38
     Section 5.10  Rights and Remedies Cumulative .......................................................   38
     Section 5.11  Delay or Omission Not Waiver .........................................................   39
     Section 5.12  Control by Holders ...................................................................   39
     Section 5.13  Waiver of Past Defaults ..............................................................   39
     Section 5.14  Undertaking for Costs ................................................................   40
     Section 5.15  Waiver of Usury, Stay or Extension Laws ..............................................   40

ARTICLE 6 THE TRUSTEE ...................................................................................   40

     Section 6.1   Certain Duties and Responsibilities ..................................................   40
     Section 6.2   Notice of Defaults ...................................................................   40
     Section 6.3   Certain Rights of Trustee ............................................................   41
     Section 6.4   Not Responsible for Recitals or Issuance of Securities ...............................   42
     Section 6.5   May Hold Securities and Act as Trustee under Other Indentures ........................   42
     Section 6.6   Money Held in Trust ..................................................................   43
     Section 6.7   Compensation and Reimbursement .......................................................   43
     Section 6.8   Conflicting Interests ................................................................   43
     Section 6.9   Corporate Trustee Required; Eligibility ..............................................   43
     Section 6.10  Resignation and Removal; Appointment of Successor ....................................   44
     Section 6.11  Acceptance of Appointment by Successor ...............................................   45
     Section 6.12  Merger, Conversion, Consolidation or Succession to Business ..........................   46
     Section 6.13  Preferential Collection of Claims Against Company ....................................   46
     Section 6.14  Appointment of Authenticating Agent ..................................................   47

ARTICLE 7 HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY .............................................   48

     Section 7.1   Company to Furnish Trustee Names and Addresses of Holders ............................   48
     Section 7.2   Preservation of Information; Communications to Holders ...............................   48
     Section 7.3   Reports by Trustee ...................................................................   49
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                               TABLE OF CONTENTS
                                  (continued)

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     Section 7.4   Reports by Company ...................................................................   49

ARTICLE 8 CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE ..........................................   50

     Section 8.1   Company May Consolidate, etc. Only on Certain Terms ..................................   50
     Section 8.2   Successor Substituted ................................................................   50

ARTICLE 9 SUPPLEMENTAL INDENTURES .......................................................................   51

     Section 9.1   Supplemental Indentures Without Consent of Holders ...................................   51
     Section 9.2   Supplemental Indentures with Consent of Holders ......................................   52
     Section 9.3   Execution of Supplemental Indentures .................................................   53
     Section 9.4   Effect of Supplemental Indentures ....................................................   54
     Section 9.5   Conformity with Trust Indenture Act ..................................................   54
     Section 9.6   Reference in Securities to Supplemental Indentures ...................................   54

ARTICLE 10 COVENANTS ....................................................................................   54

     Section 10.1  Payment of Principal, Premium and Interest ...........................................   54
     Section 10.2  Maintenance of Office or Agency ......................................................   54
     Section 10.3  Money for Securities Payments To Be Held in Trust ....................................   55
     Section 10.4  Statement by Officers as to Default ..................................................   56
     Section 10.5  Existence ............................................................................   56
     Section 10.6  Maintenance of Properties ............................................................   56
     Section 10.7  Payment of Taxes and Other Claims ....................................................   57
     Section 10.8  Waiver of Certain Covenants ..........................................................   57

ARTICLE 11 REDEMPTION OF SECURITIES .....................................................................   57

     Section 11.1  Applicability of Article .............................................................   57
     Section 11.2  Election to Redeem; Notice to Trustee ................................................   57
     Section 11.3  Selection by Trustee of Securities to Be Redeemed ....................................   58
     Section 11.4  Notice of Redemption .................................................................   58
     Section 11.5  Deposit of Redemption Price ..........................................................   59
     Section 11.6  Securities Payable on Redemption Date ................................................   60
     Section 11.7  Securities Redeemed in Part ..........................................................   60

ARTICLE 12 SINKING FUNDS ................................................................................   60

     Section 12.1  Applicability of Article .............................................................   60
     Section 12.2  Satisfaction of Sinking Fund Payments with Securities ................................   61
     Section 12.3  Redemption of Securities for Sinking Fund ............................................   61

ARTICLE 13 DEFEASANCE AND COVENANT DEFEASANCE ...........................................................   61

     Section 13.1  Company's Option to Effect Defeasance or Covenant Defeasance .........................   61
     Section 13.2  Defeasance and Discharge .............................................................   62
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                                TABLE OF CONTENTS
                                   (continued)

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     Section 13.3  Covenant Defeasance ...................................................................  62
     Section 13.4  Conditions to Defeasance or Covenant Defeasance .......................................  63
     Section 13.5  Deposited Money, U. S. Government Obligations and Foreign
                    Government Obligations to be held in Trust; Miscellaneous Provisions .................  65
     Section 13.6  Reinstatement .........................................................................  65

ARTICLE 14 CONVERSION OF SECURITIES ......................................................................  66

     Section 14.1  Applicability of Article ..............................................................  66
     Section 14.2  Exercise of Conversion Privilege ......................................................  66
     Section 14.3  No Fractional Shares ..................................................................  67
     Section 14.4  Adjustment of Conversion Price ........................................................  68
     Section 14.5  Notice of Certain Corporate Actions ...................................................  68
     Section 14.6  Reservation of Shares of Common Stock .................................................  69
     Section 14.7  Payment of Certain Taxes upon Conversion ..............................................  69
     Section 14.8  Nonassessability ......................................................................  69
     Section 14.9  Provision in Case of Consolidation, Merger or Sale of Assets ..........................  69
     Section 14.10 Duties of Trustee Regarding Conversion ................................................  70
     Section 14.11 Repayment of Certain Funds upon Conversion ............................................  71
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     Certain Sections of this Indenture relating to Sections 310 through 318,
inclusive, of the Trust Indenture Act of 1939:

Section 310 (a)(1)..........................................................6.9
            (a)(2) .........................................................6.9
            (a)(3) ..............................................Not Applicable
            (a)(4) ..............................................Not Applicable
            (b) ......................................................6.8, 6.10
Section 311 (a) ...........................................................6.13
            (b) ...........................................................6.13
Section 312 (a) .......................................................7.1, 7.2
            (b) ............................................................7.2
            (c) ............................................................7.2
Section 313 (a) ............................................................7.3
            (b) ............................................................7.3
            (c) ............................................................7.3
            (d) ............................................................7.3
Section 314 (a) ............................................................7.4
            (a)(4) ..................................................10.1, 10.4
            (b) .................................................Not Applicable
            (c)(1) .........................................................1.2
            (c)(2) .........................................................1.2
            (c)(3) ..............................................Not Applicable
            (d) .................................................Not Applicable
            (e) ............................................................1.2
Section 315 (a) ............................................................6.1
            (b) ............................................................6.2
            (c) ............................................................6.1
            (d) ............................................................6.1
            (e) ...........................................................5.14
Section 316 (a) ............................................................1.1
            (a)(1)(A) ................................................5.2, 5.12
            (a)(1)(B) .....................................................5.13
            (a)(2) ..............................................Not Applicable
            (b) ............................................................5.8
            (c) ............................................................1.4
Section 317 (a)(1) .........................................................5.3
            (a)(2) .........................................................5.4
            (b) ...........................................................10.3
Section 318 (a) ............................................................1.7

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

                                      -v-

<PAGE>

     INDENTURE, dated as of ____________, 2002, between NPS Pharmaceuticals,
Inc., a corporation duly organized and existing under the laws of the State of
Delaware (herein called the "Company"), having its principal executive office at
420 Chipeta Way, Salt Lake City, Utah 84108, and U.S. Bank National Association,
a national banking association, as Trustee (herein called the "Trustee").

                             RECITALS OF THE COMPANY

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

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

                   NOW, THEREFORE, THIS INDENTURE WITNESSETH:

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

                                    ARTICLE 1

             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

Section 1.1   Definitions.

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

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

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

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

              (4) all references to "$" refer to the lawful currency of the
     United States of America;

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

<PAGE>

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

     "Act," when used with respect to any Holder, has the meaning specified in
Section 1.4.

     "Affiliate" of any specified Person means any other Person directly or
indirectly controlling or controlled by or under direct or indirect common
control with such specified Person.

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

     "Board of Directors" means either the board of directors of the Company or
any duly authorized committee of that board empowered to act for it with respect
to this Indenture.

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

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

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

     "Common Stock" includes any stock of any class of the Company which has no
preference in respect of dividends or of amounts payable in the event of any
voluntary or involuntary liquidation, dissolution or winding-up of the Company
and which is not subject to redemption by the Company; provided, however,
                                                       --------  -------
subject to the provisions of Section 14.9, shares issuable upon conversion of
Securities shall include only shares of the class designated as Common Stock of
the Company at the date of this Indenture or shares of any class or classes
resulting from any reclassification or reclassifications thereof and which have
no preference in respect of dividends or of amounts payable in the event of any
voluntary or involuntary liquidation, dissolution or winding-up of the Company
and which are not subject to redemption by the Company; provided, further that
                                                        --------  -------
if at any time there shall be more than one such resulting class, the shares of
each such class then so issuable shall be substantially in the proportion which
the total number of shares of such class resulting from all such
reclassifications bears to the total number of shares of all such classes
resulting from all such reclassifications.

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

                                                                             -2-

<PAGE>

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

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

     "Corporate Trust Office" means the corporate trust office of the Trustee at
180 East Fifth Street, St. Paul, Minnesota 55101, Attention: Corporate Trust
Department, or such other office, designated by the Trustee by written notice to
the Company, at which at any particular time its corporate trust business shall
be administered.

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

     "Covenant Defeasance" has the meaning specified in Section 13.3.

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

     "Defeasance" has the meaning specified in Section 13.2.

     "Depositary" means, with respect to Securities of any series issuable in
whole or in part in the form of one or more Global Securities, a clearing agency
registered under the Exchange Act that is designated to act as Depositary for
such Securities as contemplated by Section 3.1.

     "euro" or "euros" means the currency adopted by those nations participating
in the third stage of the economic and monetary union provisions of the Treaty
on European Union, signed at Maastricht on February 7, 1992.

     "European Economic Area" means the member nations of the European Economic
Area pursuant to the Oporto Agreement on the European Economic Area dated May 2,
1992, as amended.

     "European Union" means the member nations of the European Union established
by the Treaty of European Union, signed at Maastricht on February 2, 1992, which
amended the Treaty of Rome establishing the European Community.

     "Event of Default" has the meaning specified in Section 5.1.

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

     "Expiration Date" has the meaning specified in Section 1.4.

                                                                             -3-

<PAGE>

     "Foreign Government Obligation" means with respect to Securities of any
series which are not denominated in the currency of the United States of America
(x) any security which is (i) a direct obligation of the government which issued
or caused to be issued the currency in which such security is denominated and
for the payment of which obligation its full faith and credit is pledged or,
with respect to Securities of any series which are denominated in euros, a
direct obligation of any member nation of the European Union for the payment of
which obligation the full faith and credit of the respective nation is pledged
so long as such nation has a credit rating at least equal to that of the highest
rated member nation of the European Economic Area, or (ii) an obligation of a
Person controlled or supervised by and acting as an agency or instrumentality of
a government specified in clause (i) above the payment of which is
unconditionally guaranteed as a full faith and credit obligation by the such
government, which, in either case (i) or (ii), is not callable or redeemable at
the option of the issuer thereof, and (y) any depositary receipt issued by a
bank (as defined in Section 3(a)(2) of the Securities Act) as custodian with
respect to any Foreign Government Obligation which is specified in clause (x)
above and held by such bank for the account of the holder of such depositary
receipt, or with respect to any specific payment of principal of or interest on
any Foreign Government Obligation which is so specified and held, provided that
(except as required by law) such custodian is not authorized to make any
deduction from the amount payable to the holder of such depositary receipt from
any amount received by the custodian in respect of the Foreign Government
Obligation or the specific payment of principal or interest evidenced by such
depositary receipt.

     "Global Security" means a Security that evidences all or part of the
Securities of any series and bears the legend set forth in Section 2.4 (or such
legend as may be specified as contemplated by Section 3.1 for such Securities).

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

     "Indenture" means this instrument as originally executed and as it may from
time to time be supplemented or amended by one or more indentures supplemental
hereto entered into pursuant to the applicable provisions hereof, including, for
all purposes of this instrument and any such supplemental indenture, the
provisions of the Trust Indenture Act that are deemed to be a part of and govern
this instrument and any such supplemental indenture, respectively. The term
"Indenture" shall also include the terms of particular series of Securities
established as contemplated by Section 3.1; that if at any time more than one
Person is acting as Trustee under this Indenture due to the appointment of one
or more separate Trustees for any one or more separate series of Securities,
"Indenture" shall mean, with respect to such series of Securities for which any
such Person is Trustee, 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 pursuant to the applicable provisions hereof and shall
include the terms of particular series of Securities for which such Person is
Trustee established as contemplated by Section 3.1, exclusive however, of any
provisions or terms which relate solely to other series of Securities for which
such Person is not Trustee, regardless of when such terms or provisions were
adopted, and exclusive of any provisions or terms adopted by means of one or
more indentures supplemental hereto executed and delivered after such Person had
become such Trustee, but to which such person, as such Trustee, was not a party;
provided, further that in the event that this Indenture is supplemented or
--------  -------
amended by one or

                                                                             -4-

<PAGE>

more indentures supplemental hereto which are only applicable to certain series
of Securities, the term "Indenture" for a particular series of Securities shall
only include the supplemental indentures applicable thereto.

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

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

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

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

     "Notice of Default" means a written notice of the kind specified in Section
5.1(4).

     "Officers' Certificate" means a certificate signed by the Chairman of the
Board, a Vice Chairman of the Board, the Chief Executive Officer, the President
or a Vice President, and by the principal financial officer, the Treasurer, an
Assistant Treasurer, the Secretary or an Assistant Secretary, of the Company,
and delivered to the Trustee. One of the officers signing an Officers'
Certificate given pursuant to Section 10.4 shall be the principal executive,
financial or accounting officer of the Company.

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

     "Original Issue Discount Security" means any Security which provides for an
amount less than the principal amount thereof to be due and payable upon a
declaration of acceleration of the Maturity thereof pursuant to Section 5.2.

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

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

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

                                                                             -5-

<PAGE>

          (3) Securities as to which Defeasance has been effected pursuant to
     Section 13.2; and

          (4) Securities which have been paid pursuant to Section 3.6 or in
     exchange for or in lieu of which other Securities have been authenticated
     and delivered pursuant to this Indenture, other than any such Securities in
     respect of which there shall have been presented to the Trustee proof
     satisfactory to it that such Securities are held by a bona fide purchaser
     in whose hands such Securities are valid obligations of the Company;

provided, however, that in determining whether the Holders of the requisite
--------  -------
principal amount of the Outstanding Securities have given, made or taken any
request, demand, authorization, direction, notice, consent, waiver or other
action hereunder as of any date, (A) the principal amount of an Original Issue
Discount Security which shall be deemed to be Outstanding shall be the amount of
the principal thereof which would be due and payable as of such date upon
acceleration of the Maturity thereof to such date pursuant to Section 5.2, (B)
if, as of such date, the principal amount payable at the Stated Maturity of a
Security is not determinable, the principal amount of such Security which shall
be deemed to be Outstanding shall be the amount as specified or determined as
contemplated by Section 3.1, (C) the principal amount of a Security denominated
in one or more non-U.S. dollar currencies or currency units which shall be
deemed to be Outstanding shall be the U.S. dollar equivalent, determined as of
such date in the manner provided as contemplated by Section 3.1, of the
principal amount of such Security (or, in the case of a Security described in
clause (A) or (B) above, of the amount determined as provided in such clause),
and (D) Securities owned by the Company or any other obligor upon the Securities
or any Affiliate of the Company or of such other obligor shall be disregarded
and deemed not to be Outstanding, except that, in determining whether the
Trustee shall be protected in relying upon any such request, demand,
authorization, direction, notice, consent, waiver or other action, only
Securities which the Trustee knows to be so owned shall be so disregarded.
Securities so owned which have been pledged in good faith may be regarded as
Outstanding if the pledgee establishes to the satisfaction of the Trustee the
pledgee's right so to act with respect to such Securities and that the pledgee
is not the Company or any other obligor upon the Securities or any Affiliate of
the Company or of such other obligor.

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

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

     "Place of Payment," when used with respect to the Securities of any series,
means the place or places where the principal of and any premium and interest on
the Securities of that series are payable as specified as contemplated by
Section 3.1.

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

                                                                             -6-

<PAGE>

lieu of a mutilated, destroyed, lost or stolen Security shall be deemed to
evidence the same debt as the mutilated, destroyed, lost or stolen Security.

     "Record Date" means any Regular Record Date or Special Record Date.

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

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

     "Regular Record Date" for the interest payable on any Interest Payment Date
on the Securities of any series means the date specified for that purpose as
contemplated by Section 3.1.

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

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

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

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

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

     "Subsidiary" means a Person of which at least a majority of the outstanding
voting stock having the power to elect a majority of the board of directors of
such Person (in the case of a corporation) is, or of which at least a majority
of the equity interests (in the case of a Person which is not a corporation)
are, at the time owned, directly or indirectly, by the Company or by one or more
other Subsidiaries, or by the Company and one or more other Subsidiaries. For
the purposes of this definition, "voting stock" means stock which ordinarily has
voting power for the election of directors, whether at all times or only so long
as no senior class of stock has such voting power by reason of any contingency.

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

                                                                             -7-

<PAGE>

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

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

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

Section 1.2   Compliance Certificates and Opinions.

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

     Every certificate or opinion with respect to compliance with a condition or
covenant provided for in this Indenture shall include,

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

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

                                                                             -8-

<PAGE>

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

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

Section 1.3  Form of Documents Delivered to Trustee.

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

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

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

Section 1.4  Acts of Holders; Record Dates.

     Any request, demand, authorization, direction, notice, consent, waiver or
other action provided or permitted by this Indenture to be given, made or taken
by Holders may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Holders in person or by agent duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required, to the Company. The
Trustee shall promptly deliver to the Company copies of all such instrument or
instruments delivered to the Trustee. Such instrument or instruments (and the
action embodied therein and evidenced thereby) are herein sometimes referred to
as the "Act" of the Holders signing such instrument or instruments. Proof of
execution of any such instrument or of a writing appointing any such agent shall
be sufficient for any purpose of this Indenture and (subject to Section 6.1)
conclusive in favor of the Trustee and the Company, if made in the manner
provided in this Section.

                                                                             -9-

<PAGE>

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

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

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

     The Company may set any day as a record date for the purpose of determining
the Holders of Outstanding Securities of any series entitled to give, make or
take any request, demand, authorization, direction, vote, notice, consent,
waiver or other action provided or permitted by this Indenture to be given, made
or taken by Holders of Securities of such series, provided that the Company may
                                                  --------
not set a record date for, and the provisions of this paragraph shall not apply
with respect to, the giving or making of any notice, declaration, request or
direction referred to in the next paragraph. If any record date is set pursuant
to this paragraph, the Holders of Outstanding Securities of the relevant series
on such record date, and no other Holders, shall be entitled to take the
relevant action, whether or not such Holders remain Holders after such record
date; provided that no such action shall be effective hereunder unless taken on
      --------
or prior to the applicable Expiration Date by Holders of the requisite principal
amount of Outstanding Securities of such series on such record date. Nothing in
this paragraph shall be construed to prevent the Company from setting a new
record date for any action for which a record date has previously been set
pursuant to this paragraph (whereupon the record date previously set shall
automatically and with no action by any Person be canceled and of no effect),
and nothing in this paragraph shall be construed to render ineffective any
action taken by Holders of the requisite principal amount of Outstanding
Securities of the relevant series on the date such action is taken. Promptly
after any record date is set pursuant to this paragraph, the Company, at its own
expense, shall cause notice of such record date, the proposed action by Holders
and the applicable Expiration Date to be given to the Trustee in writing and to
each Holder of Securities of the relevant series in the manner set forth in
Section 1.6.

     The Trustee may set any day as a record date for the purpose of determining
the Holders of Outstanding Securities of any series entitled to join in the
giving or making of (i) any Notice of Default, (ii) any declaration of
acceleration referred to in Section 5.2, (iii) any request to institute
proceedings referred to in Section 5.7(2) or (iv) any direction referred to in
Section 5.12, in each case with respect to Securities of such series. If any
record date is set pursuant to this paragraph, the Holders of Outstanding
Securities of such series on such record date, and no other Holders, shall be

                                                                            -10-

<PAGE>

entitled to join in such notice, declaration, request or direction, whether or
not such Holders remain Holders after such record date; provided that no such
                                                        --------
action shall be effective hereunder unless taken on or prior to the applicable
Expiration Date by Holders of the requisite principal amount of Outstanding
Securities of such series on such record date. Nothing in this paragraph shall
be construed to prevent the Trustee from setting a new record date for any
action for which a record date has previously been set pursuant to this
paragraph (whereupon the record date previously set shall automatically and with
no action by any Person be canceled and of no effect), and nothing in this
paragraph shall be construed to render ineffective any action taken by Holders
of the requisite principal amount of Outstanding Securities of the relevant
series on the date such action is taken. Promptly after any record date is set
pursuant to this paragraph, the Trustee, at the Company's expense, shall cause
notice of such record date, the proposed action by Holders and the applicable
Expiration Date to be given to the Company in writing and to each Holder of
Securities of the relevant series in the manner set forth in Section 1.6.

     With respect to any record date set pursuant to this Section, the party
hereto which sets such record dates may designate any day as the "Expiration
Date" and from time to time may change the Expiration Date to any earlier or
later day; provided that no such change shall be effective unless notice of the
           --------
proposed new Expiration Date is given to the other party hereto in writing, and
to each Holder of Securities of the relevant series in the manner set forth in
Section 1.6, on or prior to the existing Expiration Date. If an Expiration Date
is not designated with respect to any record date set pursuant to this Section,
the party hereto which set such record date shall be deemed to have initially
designated the 180th day after such record date as the Expiration Date with
respect thereto, subject to its right to change the Expiration Date as provided
in this paragraph. Notwithstanding the foregoing, no Expiration Date shall be
later than the 180th day after the applicable record date.

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

Section 1.5  Notices, etc., to Trustee and Company.

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

             (1) the Trustee by any Holder or by the Company shall be sufficient
     for every purpose hereunder if made, given, furnished or filed in writing
     (or by facsimile transmissions, provided that oral confirmation of receipt
                                     --------
     shall have been received) to or with the Trustee at its Corporate Trust
     Office, Attention: Corporate Trust Department, or

             (2) the Company by the Trustee or by any Holder shall be sufficient
     for every purpose hereunder (unless otherwise herein expressly provided) if
     in writing and mailed, first-class postage prepaid, personally delivered or
     sent via overnight courier to the Company addressed to it at the address of
     its principal

                                                                            -11-

<PAGE>

     office specified in the first paragraph of this instrument or at any other
     address previously furnished in writing to the Trustee by the Company,
     Attention: Chief Financial Officer.

Section 1.6  Notice to Holders; Waiver.

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

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

Section 1.7  Conflict with Trust Indenture Act.

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

Section 1.8  Effect of Headings and Table of Contents.

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

Section 1.9  Successors and Assigns.

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

Section 1.10 Separability Clause.

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

                                                                            -12-

<PAGE>

Section 1.11  Benefits of Indenture.

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

Section 1.12  Governing Law.

     THIS INDENTURE AND THE SECURITIES SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT GIVING EFFECT TO SUCH
STATE'S CONFLICTS OF LAWS PRINCIPLES.

Section 1.13  Legal Holidays.

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

Section 1.14  Indenture and Securities Solely Corporate Obligations.

     No recourse for the payment of the principal of or premium, if any, or
interest on any Security, or for any claim based thereon or otherwise in respect
thereof, and no recourse under or upon any obligation, covenant or agreement of
the Company in this Indenture or in any supplemental indenture or in any
Security, or because of the creation of any indebtedness represented thereby,
shall be had against any incorporator, stockholder, employee, agent, officer,
director or subsidiary, as such, past, present or future, of the Company or of
any successor corporation, either directly or through the Company or any
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 all such liability is hereby expressly waived and
released as a condition of, and as a consideration for, the execution of this
Indenture and the issue of the Securities.

Section 1.15  Indenture May be Executed in Counterparts.

     This instrument 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.

                                                                            -13-

<PAGE>

                                   ARTICLE 2

                                 SECURITY FORMS

Section 2.1   Forms Generally.

     The Securities of each series shall be in substantially the form set forth
in this Article, or in such other form as shall be established by or pursuant to
a Board Resolution or in one or more indentures supplemental hereto, in each
case with such appropriate insertions, omissions, substitutions and other
variations as are required or permitted by this Indenture, and may have such
letters, numbers or other marks of identification and such legends or
endorsements placed thereon as may be required to comply with the rules of any
securities exchange or Depositary therefor or as may, consistently herewith, be
determined by the officers executing such Securities, as evidenced by their
execution thereof. If the form of Securities of any series is established by
action taken pursuant to a Board Resolution, a copy of an appropriate record of
such action shall be certified by the Secretary or an Assistant Secretary of the
Company and delivered to the Trustee at or prior to the delivery of the Company
Order contemplated by Section 3.3 for the authentication and delivery of such
Securities. Any such Board Resolution or record of such action shall have
attached thereto a true and correct copy of the form of Security referred to
therein approved by or pursuant to such Board Resolution.

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

Section 2.2   Form of Face of Security.

     [INSERT ANY LEGEND REQUIRED BY THE INTERNAL REVENUE CODE AND THE
REGULATIONS THEREUNDER.]

                            NPS PHARMACEUTICALS, INC.

NO.  __________                                                      $__________

                                                              CUSIP:____________

      _____________________________________________________________________

     NPS Pharmaceuticals, Inc., a corporation duly organized and existing under
the laws of Delaware (herein called the "Company," which term includes any
successor Person under the Indenture hereinafter referred to), for value
received, hereby promises to pay to ____________, or registered assigns, the
principal sum of _____________ dollars on _____________________________ [if the
Security is to bear interest prior to Maturity, insert --, and to pay interest
thereon from __________ or from the most recent Interest Payment Date to which
interest has been paid or duly provided for, semi-annually on ___________ and
__________

                                                                            -14-

<PAGE>

in each year, commencing _________, at the rate of ___% per annum, until the
principal hereof is paid or made available for payment [if applicable, insert
--, provided that any principal and premium, and any such installment of
    --------
interest, which is overdue shall bear interest at the rate of ___% per annum (to
the extent that the payment of such interest shall be legally enforceable), from
the dates such amounts are due until they are paid or made available for
payment, and such interest shall be payable on demand]. The interest so payable,
and punctually paid or duly provided for, on any Interest Payment Date will, as
provided in such Indenture, be paid to the Person in whose name this Security
(or one or more Predecessor Securities) is registered at the close of business
on the Regular Record Date for such interest, which shall be the ______ or
______ (whether or not a Business Day), as the case may be, next preceding such
Interest Payment Date. Any such interest not so punctually paid or duly provided
for will forthwith cease to be payable to the Holder on such Regular Record Date
and may either be paid to the Person in whose name this Security (or one or more
Predecessor Securities) is registered at the close of business on a Special
Record Date for the payment of such Defaulted Interest to be fixed by the
Trustee, notice whereof shall be given to Holders of Securities of this series
not less than 10 days prior to such Special Record Date, or be paid at any time
in any other lawful manner not inconsistent with the requirements of any
securities exchange on which the Securities of this series may be listed, and
upon such notice as may be required by such exchange, all as more fully provided
in said Indenture].

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

     Payment of the principal of (and premium, if any) and [if applicable,
insert -- any such] interest on this Security will be made at the office or
agency of the Company maintained for that purpose in _______, in such coin or
currency of the United States of America as at the time of payment is legal
tender for payment of public and private debts [if applicable, insert -- ;
provided, however, that at the option of the Company payment of interest may be
--------  -------
made by check mailed to the address of the Person entitled thereto as such
address shall appear in the Security Register].

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

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

                                                                            -15-

<PAGE>

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

Dated: ____________                             NPS PHARMACEUTICALS, INC.

                                                By: ____________________________

                                                Title: _________________________

ATTEST:

_________________________________

Section 2.3   Form of Reverse of Security.

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

     [If applicable, insert -- The Securities of this series are subject to
redemption upon not less than [if applicable, insert -- 30] days' notice by
mail, [if applicable, insert-- (1) on __________ in any year commencing with the
year ________ and ending with the year ________ through operation of the sinking
fund for this series at a Redemption Price equal to 100% of the principal
amount, and (2)] at any time [if applicable, insert-- on or after __________,
20__], as a whole or in part, at the election of the Company, at the following
Redemption Prices (expressed as percentages of the principal amount): If
redeemed [if applicable, insert-- on or before __________, ___%, and if
redeemed] during the 12-month period beginning ____________ of the years
indicated,

Year      Redemption Price        Year        Redemption Price
----      ----------------        ----        ----------------

and thereafter at a Redemption Price equal to ___% of the principal amount,
together in the case of any such redemption [if applicable, insert-- (whether
through operation of the sinking fund or otherwise)] with accrued interest to
the Redemption Date, but interest installments whose Stated Maturity is on or
prior to such Redemption Date will be payable to the Holders of such Securities,
or

                                                                            -16-

<PAGE>

one or more Predecessor Securities, of record at the close of business on the
relevant Record Dates referred to on the face hereof, all as provided in the
Indenture.]

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

                                                    Redemption Price For
                         Redemption Price For     Redemption Otherwise Than
                          Redemption Through           Through Operation
                           Operation of the                 of the
            Year             Sinking Fund                Sinking Fund
            ----             ------------                ------------

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

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

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

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

                                                                           -17-

<PAGE>

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

     [If the Security is convertible into Common Stock of the Company, insert--
Subject to the provisions of the Indenture, the Holder of this Security is
entitled, at its option, at any time on or before [insert date] (except that, in
case this Security or any portion hereof shall be called for redemption, such
right shall terminate with respect to this Security or portion hereof, as the
case may be, so called for redemption at the close of business on the first
Business Day next preceding the date fixed for redemption as provided in the
Indenture unless the Company defaults in making the payment due upon
redemption), to convert the principal amount of this Security (or any portion
hereof which is $1,000 or an integral multiple thereof), into fully paid and
non-assessable shares (calculated as to each conversion to the nearest 1/100th
of a share) of the Common Stock of the Company, as said shares shall be
constituted at the date of conversion, at the conversion price of $______
principal amount of Securities for each share of Common Stock, or at the
adjusted conversion price in effect at the date of conversion determined as
provided in the Indenture, upon surrender of this Security, together with the
conversion notice hereon duly executed, to the Company at the designated office
or agency of the Company in __________, accompanied (if so required by the
Company) by instruments of transfer, in form satisfactory to the Company and to
the Trustee, duly executed by the Holder or by its duly authorized attorney in
writing. Such surrender shall, if made during any period beginning at the close
of business on a Regular Record Date and ending at the opening of business on
the Interest Payment Date next following such Regular Record Date (unless this
Security or the portion being converted shall have been called for redemption on
a Redemption Date during the period beginning at the close of business on a
Regular Record Date and ending at the opening of business on the first Business
Day after the next succeeding Interest Payment Date, or if such Interest Payment
Date is not a Business Day, the second such Business Day), also be accompanied
by payment in funds acceptable to the Company of an amount equal to the interest
payable on such Interest Payment Date on the principal amount of this Security
then being converted. Subject to the aforesaid requirement for payment and, in
the case of a conversion after the Regular Record Date next preceding any
Interest Payment Date and on or before such Interest Payment Date, to the right
of the Holder of this Security (or any Predecessor Security) of record at such
Regular Record Date to receive an installment of interest (with certain
exceptions provided in the Indenture), no adjustment is to be made on conversion
for interest accrued hereon or for dividends on shares of Common Stock issued on
conversion. The Company is not required to issue fractional shares upon any such
conversion, but shall make adjustment therefor in cash on the basis of the
current market value of such fractional interest as provided in the Indenture.
The conversion price is subject to adjustment as provided in the Indenture. In
addition, the Indenture provides that in case of certain consolidations or
mergers to which the Company is a party or the sale of substantially all of the
assets of the Company, the Indenture shall be amended, without the consent of
any Holders of Securities, so that this Security, if then outstanding, will be
convertible thereafter, during the period this Security shall be convertible as
specified above, only into the kind and amount of securities, cash and other
property receivable upon the consolidation, merger or sale by a holder of the
number of shares of Common Stock into which this Security might have been

                                                                            -18-

<PAGE>

converted immediately prior to such consolidation, merger or sale (assuming
such holder of Common Stock failed to exercise any rights of election and
received per share the kind and amount received per share by a plurality of
non-electing shares). In the event of conversion of this Security in part only,
a new Security or Securities for the unconverted portion hereof shall be issued
in the name of the Holder hereof upon the cancellation hereof.]

     [If the Security is convertible into other securities of the Company,
specify the conversion features.]

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

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

     The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of more than 50% in principal amount of the Securities at
the time Outstanding of each series to be affected. The Indenture also contains
provisions permitting the Holders of specified percentages in principal amount
of the Securities of each series at the time Outstanding, on behalf of the
Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the
Indenture and their consequences. Any such consent or waiver by the Holder of
this Security shall be conclusive and binding upon such Holder and upon all
future Holders of this Security and of any Security issued upon the registration
of transfer hereof or in exchange herefor or in lieu hereof, whether or not
notation of such consent or waiver is made upon this Security.

     As provided in and subject to the provisions of the Indenture, the Holder
of this Security shall not have the right to institute any proceeding with
respect to the Indenture or for the appointment of a receiver or trustee or for
any other remedy thereunder, unless such Holder shall have previously given the
Trustee written notice of a continuing Event of Default with respect to the
Securities of this series, the Holders of not less than a majority in principal
amount of the Securities of this series at the time Outstanding shall have made
written request to the Trustee to institute proceedings in respect of such Event
of Default as Trustee and offered the Trustee reasonable indemnity, and the
Trustee shall not have received from the Holders of a majority in principal
amount of Securities of this series at the time Outstanding a direction
inconsistent with such request,

                                                                           -19-

<PAGE>

and shall have failed to institute any such proceeding, for 60 days after
receipt of such notice, request and offer of indemnity. The foregoing shall not
apply to any suit instituted by the Holder of this Security for the enforcement
of any payment of principal hereof or any premium or interest hereon on or after
the respective due dates expressed herein.

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

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

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

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

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

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

Section 2.4 Form of Legend for Global Securities.

     Unless otherwise specified as contemplated by Section 3.1 for the
Securities evidenced thereby, every Global Security authenticated and delivered
hereunder shall bear a legend in substantially the following form:

THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE
HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF

                                                                           -20-

<PAGE>

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

Section 2.5  Form of Trustee's Certificate of Authentication.

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

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

                                      U.S. Bank National Association,
                                      as Trustee

                                      By:_____________________________________
                                            Authorized Officer

Section 2.6  Form of Conversion Notice.

     Conversion notices shall be in substantially the following form:

To NPS Pharmaceuticals, Inc.:

     The undersigned owner of this Security hereby irrevocably exercises the
option to convert this Security, or portion hereof (which is $1,000 or an
integral multiple thereof) below designated, into shares of Common Stock of the
Company in accordance with the terms of the Indenture referred to in this
Security, and directs that the shares issuable and deliverable upon the
conversion, together with any check in payment for fractional shares and any
Securities representing any unconverted principal amount hereof, be issued and
delivered to the registered holder hereof unless a different name has been
indicated below. If this Notice is being delivered on a date after the close of
business on a Regular Record Date and prior to the opening of business on the
related Interest Payment Date (unless this Security or the portion thereof being
converted has been called for redemption on a Redemption Date during the period
beginning at the close of business on a Regular Record Date and ending at the
opening of business on the first Business Day after the next succeeding Interest
Payment Date, or if such Interest Payment Date is not a Business Day, the second
such Business Day), this Notice is accompanied by payment, in funds acceptable
to the Company, of an amount equal to the interest payable on such Interest
Payment Date of the principal of this Security to be converted. If shares are to
be issued in the name of a person other than the undersigned, the undersigned
will pay all transfer taxes payable with respect hereto. Any amount required to
be paid by the undersigned on account of interest accompanies this Security.

                                                                           -21-

<PAGE>

     Principal Amount to be Converted
(in an integral multiple of $1,000, if less than all)

     U.S. $_________

Dated:  ___________
                                      Signature(s) must be guaranteed by an
                                      eligible guarantor institution (banks,
                                      stock brokers, savings and loan
                                      associations and credit unions with
                                      membership in an approved signature
                                      guarantee medallion program) pursuant to
                                      Securities and Exchange Commission Rule
                                      17Ad-15.

                                      __________________________________________
                                      Signature Guaranty

     Fill in for registration of shares of Common Stock and Security if to be
issued otherwise than to the registered Holder.

_____________________________  _________________________________________________
(Name)                         Social Security or Other Taxpayer Identification
                               Number

_____________________________
(Address)

_____________________________
Please print Name and Address
(including zip code)

[The above conversion notice is to be modified, as appropriate, for conversion
into other securities or property of the Company.]

                                                                           -22-

<PAGE>

                                    ARTICLE 3

                                 THE SECURITIES

Section 3.1  Amount Unlimited; Issuable in Series.

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

     The Securities may be issued in one or more series. There shall be
established in or pursuant to a Board Resolution and, subject to Section 3.3,
set forth, or determined in the manner provided, in an Officers' Certificate, or
established in one or more indentures supplemental hereto, prior to the issuance
of Securities of any series,

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

          (2) any limit upon the aggregate principal amount of the Securities of
     the series which may be authenticated and delivered under this Indenture
     (except for Securities authenticated and delivered upon registration of
     transfer of, or in exchange for, or in lieu of, other Securities of the
     series pursuant to Section 3.4, 3.5, 3.6, 9.6 or 11.7 and except for any
     Securities which, pursuant to Section 3.3, are deemed never to have been
     authenticated and delivered hereunder);

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

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

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

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

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

                                                                           -23-

<PAGE>

     at the option of the Company and, if other than by a Board Resolution, the
     manner in which any election by the Company to redeem the Securities shall
     be evidenced;

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

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

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

          (11) if other than the currency of the United States of America, the
     currency, currencies or currency units in which the principal of or any
     premium or interest on any Securities of the series shall be payable and
     the manner of determining the equivalent thereof in the currency of the
     United States of America for any purpose, including for purposes of the
     definition of "Outstanding" in Section 1.1;

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

          (13) if other than the entire principal amount thereof, the portion of
     the principal amount of any Securities of the series which shall be payable
     upon declaration of acceleration of the Maturity thereof pursuant to
     Section 5.2;

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

          (15) if applicable, that the Securities of the series, in whole or any
     specified part, shall be defeasible pursuant to Section 13.2 or Section
     13.3 or both such Sections, or any other defeasance provisions applicable
     to any Securities of the series, and, if other than by a

                                                                            -24-

<PAGE>

     Board Resolution, the manner in which any election by the Company to
     defease such Securities shall be evidenced;

          (16) if applicable, the terms of any right to convert or exchange
     Securities of the series into shares of Common Stock of the Company or
     other securities or property;

          (17) if applicable, that any Securities of the series shall be
     issuable in whole or in part in the form of one or more Global Securities
     and, in such case, the respective Depositaries for such Global Securities,
     the form of any legend or legends which shall be borne by any such Global
     Security in addition to or in lieu of that set forth in Section 2.4 and any
     circumstances in addition to or in lieu of those set forth in clause (2) of
     the last paragraph of Section 3.5 in which any such Global Security may be
     exchanged in whole or in part for Securities registered, and any transfer
     of such Global Security in whole or in part may be registered, in the name
     or names of Persons other than the Depositary for such Global Security or a
     nominee thereof;

          (18) any addition to or change in the Events of Default which applies
     to any Securities of the series and any change in the right of the Trustee
     or the requisite Holders of such Securities to declare the principal amount
     thereof due and payable pursuant to Section 5.2;

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

          (20) any Authenticating Agents, Paying Agents, Security Registrars or
     such other agents necessary in connection with the issuance of the
     Securities of such series, including, without limitation, exchange rate
     agents and calculation agents;

          (21) if applicable, the terms of any security that will be provided
     for a series of Securities, including any provisions regarding the
     circumstances under which collateral may be relaxed or substituted

          (22) if applicable, the terms of any guarantees for the Securities and
     any circumstances under which there may be additional obligors on the
     Securities; and

          (23) any other terms of the series (which terms shall not be
     inconsistent with the provisions of this Indenture, except as permitted by
     Section 9.1(5)).

     All Securities of any one series shall be substantially identical except as
to denomination and except as may otherwise be provided in or pursuant to the
Board Resolution referred to above and (subject to Section 3.3) set forth, or
determined in the manner provided, in the Officers' Certificate referred to
above or in any such indenture supplemental hereto.

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

                                                                            -25-

<PAGE>

Section 3.2 Denominations.

     The Securities of each series shall be issuable only in registered form
without coupons and only in such denominations as shall be specified as
contemplated by Section 3.1. In the absence of any such specified denomination
with respect to the Securities of any series, the Securities of such series
shall be issuable in denominations of $1,000 and any integral multiple thereof.

Section 3.3 Execution, Authentication, Delivery and Dating.

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

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

     At any time and from time to time after the execution and delivery of this
Indenture, the Company may deliver Securities of any series executed by the
Company to the Trustee for authentication, together with a Company Order for the
authentication and delivery of such Securities, and the Trustee in accordance
with the Company Order shall authenticate and deliver such Securities. If the
form or terms of the Securities of the series have been established by or
pursuant to one or more Board Resolutions as permitted by Sections 2.1 and 3.1,
in authenticating such Securities, and accepting the additional responsibilities
under this Indenture in relation to such Securities, the Trustee shall be
entitled to receive, and (subject to Section 6.1) shall be fully protected in
relying upon, a copy of such Board Resolution, the Officers' Certificate setting
forth the terms of the series and an Opinion of Counsel, with such Opinion of
Counsel stating,

          (1) if the form of such Securities has been established by or pursuant
     to Board Resolution as permitted by Section 2.1, that such form has been
     established in conformity with the provisions of this Indenture;

          (2) if the terms of such Securities have been established by or
     pursuant to Board Resolution as permitted by Section 3.1, that such terms
     have been established in conformity with the provisions of this Indenture;
     and

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

                                                                            -26-

<PAGE>

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

     Notwithstanding the provisions of Section 3.1 and of the preceding
paragraph, if all Securities of a series are not to be originally issued at one
time, it shall not be necessary to deliver the Officers' Certificate otherwise
required pursuant to Section 3.1 or the Company Order and Opinion of Counsel
otherwise required pursuant to such preceding paragraph at or prior to the
authentication of each Security of such series if such documents are delivered
at or prior to the authentication upon original issuance of the first Security
of such series to be issued.

     Each Security shall be dated the date of its authentication.

     No Security shall be entitled to any benefit under this Indenture or be
valid or obligatory for any purpose unless there appears on such Security a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by manual signature, and such certificate upon any
Security shall be conclusive evidence, and the only evidence, that such Security
has been duly authenticated and delivered hereunder. Notwithstanding the
foregoing, if any Security shall have been authenticated and delivered hereunder
but never issued and sold by the Company, and the Company shall deliver such
Security to the Trustee for cancellation as provided in Section 3.9, for all
purposes of this Indenture such Security shall be deemed never to have been
authenticated and delivered hereunder and shall never be entitled to the
benefits of this Indenture.

     Neither the Company nor the Trustee shall have any responsibility for any
defect in the CUSIP number that appears on any Security, check, advice of
payment or redemption notice, and any such document may contain a statement to
the effect that CUSIP numbers have been assigned by an independent service for
convenience of reference and that neither the Company nor the Trustee shall be
liable for any inaccuracy in such numbers.

Section 3.4  Temporary Securities.

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

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

                                                                            -27-

<PAGE>

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

Section 3.5  Registration; Registration of Transfer and Exchange.

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

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

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

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

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

     No service charge shall be made for any registration of transfer or
exchange of Securities, but the Company may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection
with any registration of transfer or exchange of Securities, other than
exchanges pursuant to Section 3.4, 9.6 or 11.7 not involving any transfer.

     If the Securities of any series (or of any series and specified tenor) are
to be redeemed in part, the Company shall not be required (A) to issue, register
the transfer of or exchange any Securities of that series (or of that series and
specified tenor, as the case may be) during a period beginning at the opening of
business 15 days before the day of the mailing of a notice of redemption of any
such Securities selected for redemption under Section 11.3 and ending at the
close of business on the day

                                                                            -28-

<PAGE>

of such mailing, or (B) to register the transfer of or exchange any Security so
selected for redemption in whole or in part, except the unredeemed portion of
any Security being redeemed in part.

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

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

          (2) Notwithstanding any other provision in this Indenture, no Global
     Security may be exchanged in whole or in part for Securities registered,
     and no transfer of a Global Security in whole or in part may be registered,
     in the name of any Person other than the Depositary for such Global
     Security or a nominee thereof unless (A) such Depositary (i) has notified
     the Company that it is unwilling or unable to continue as Depositary for
     such Global Security or (ii) has ceased to be a clearing agency registered
     under the Exchange Act, (B) there shall have occurred and be continuing an
     Event of Default with respect to such Global Security or (C) there shall
     exist such circumstances, if any, in addition to or in lieu of the
     foregoing as have been specified for this purpose as contemplated by
     Section 3.1.

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

          (4) Every Security authenticated and delivered upon registration of
     transfer of, or in exchange for or in lieu of, a Global Security or any
     portion thereof, whether pursuant to this Section, Section 3.4, 3.6, 9.6 or
     11.7 or otherwise, shall be authenticated and delivered in the form of, and
     shall be, a Global Security, unless such Security is registered in the name
     of a Person other than the Depositary for such Global Security or a nominee
     thereof.

Section 3.6  Mutilated, Destroyed, Lost and Stolen Securities.

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

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

                                                                            -29-

<PAGE>

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

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

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

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

Section 3.7  Payment of Interest; Interest Rights Preserved.

     Except as otherwise provided as contemplated by Section 3.1 with respect to
any series of Securities, interest on any Security which is payable, and is
punctually paid or duly provided for, on any Interest Payment Date shall be paid
to the Person in whose name that Security (or one or more Predecessor
Securities) is registered at the close of business on the Regular Record Date
for such interest.

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

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

                                                                            -30-

<PAGE>

     and not less than 10 days prior to the date of the proposed payment and not
     less than 10 days after the receipt by the Trustee of the notice of the
     proposed payment. The Trustee shall promptly notify the Company of such
     Special Record Date and, in the name and at the expense of the Company,
     shall cause notice of the proposed payment of such Defaulted Interest and
     the Special Record Date therefor to be given to each Holder of Securities
     of such series in the manner set forth in Section 1.6, not less than 10
     days prior to such Special Record Date. Notice of the proposed payment of
     such Defaulted Interest and the Special Record Date therefor having been so
     mailed, such Defaulted Interest shall be paid to the Persons in whose names
     the Securities of such series (or their respective Predecessor Securities)
     are registered at the close of business on such Special Record Date and
     shall no longer be payable pursuant to the following clause (2).

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

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

     Subject to the provisions of Section 14.2, in the case of any Security (or
any part thereof) which is converted after any Regular Record Date and on or
prior to the next succeeding Interest Payment Date (other than any Security the
principal of (or premium, if any, on) which shall become due and payable,
whether at Stated Maturity or by declaration of acceleration or otherwise prior
to such Interest Payment Date), interest whose Stated Maturity is on such
Interest Payment Date shall be payable on such Interest Payment Date
notwithstanding such conversion and such interest (whether or not punctually
paid or duly provided for) shall be paid to the Person in whose name that
Security (or any one or more Predecessor Securities) is registered at the close
of business on such Regular Record Date. Except as otherwise expressly provided
in the immediately preceding sentence or in Section 14.2, in the case of any
Security (or any part thereof) which is converted, interest whose Stated
Maturity is after the date of conversion of such Security (or such part thereof)
shall not be payable.

Section 3.8  Persons Deemed Owners.

     Prior to due presentment of a Security for registration of transfer, the
Company, the Trustee and any agent of the Company or the Trustee may treat the
Person in whose name such Security is registered as the owner of such Security
for the purpose of receiving payment of principal of and any premium and
(subject to Section 3.7) any interest on such Security and for all other
purposes whatsoever, whether or not such Security be overdue, and neither the
Company, the Trustee nor any agent of the Company or the Trustee shall be
affected by notice to the contrary.

                                                                            -31-

<PAGE>

Section 3.9   Cancellation.

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

Section 3.10  Computation of Interest.

     Except as otherwise specified as contemplated by Section 3.1 for Securities
of any series, interest on the Securities of each series shall be computed on
the basis of a 360-day year of twelve 30-day months.

                                    ARTICLE 4

                           SATISFACTION AND DISCHARGE

Section 4.1   Satisfaction and Discharge of Indenture.

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

          (1)  either

               (A) all Securities theretofore authenticated and delivered (other
than (i) Securities which have been destroyed, lost or stolen and which have
been replaced or paid as provided in Section 3.6 and (ii) Securities for whose
payment money has theretofore been deposited in trust or segregated and held in
trust by the Trustee or the Company and thereafter repaid to the Company or
discharged from such trust, as provided in Section 10.3) have been delivered to
the Trustee for cancellation; or

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

                   (i) have become due and payable, or

                                                                            -32-

<PAGE>

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

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

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

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

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

     Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Company to the Trustee under Section 6.7, the obligations of
the Trustee to any Authenticating Agent under Section 6.14 and, if money shall
have been deposited with the Trustee pursuant to subclause (B) of clause (1) of
this Section, the obligations of the Trustee under Section 4.2 and the last
paragraph of Section 10.3 shall survive.

Section 4.2  Application of Trust Money.

     Subject to the provisions of the last paragraph of Section 10.3, all money
deposited with the Trustee pursuant to Section 4.1 shall be held in trust and
applied by it, in accordance with the provisions of the Securities and this
Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the Persons entitled thereto, of the principal and any premium and
interest for whose payment such money has been deposited with the Trustee.

                                    ARTICLE 5

                                    REMEDIES

Section 5.1  Events of Default.

     "Event of Default," wherever used herein with respect to Securities of any
series, means any one of the following events (whatever the reason for such
Event of Default and whether it shall be

                                                                            -33-

<PAGE>

voluntary or involuntary or be effected by operation of law or pursuant to any
judgment, decree or order of any court or any order, rule or regulation of any
administrative or governmental body), unless in the Board Resolution,
supplemental indenture or Officers' Certificate establishing such series, it is
provided that such series shall not have the benefit of said Event of Default:

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

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

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

          (4) default in the performance, or breach, of any covenant or warranty
     of the Company in this Indenture (other than a covenant or warranty a
     default in whose performance or whose breach is elsewhere in this Section
     specifically dealt with or which has expressly been included in this
     Indenture solely for the benefit of series of Securities other than that
     series), and continuance of such default or breach for a period of 90 days
     after there has been given, by registered or certified mail, to the Company
     by the Trustee or to the Company and the Trustee by the Holders of at least
     25% in principal amount of the Outstanding Securities of that series a
     written notice specifying such default or breach and requiring it to be
     remedied and stating that such notice is a "Notice of Default" hereunder;
     or

          (5) the entry by a court having jurisdiction in the premises of (A) a
     decree or order for relief in respect of the Company in an involuntary case
     or proceeding under any applicable Federal or State bankruptcy, insolvency,
     reorganization or other similar law or (B) a decree or order adjudging the
     Company a bankrupt or insolvent, or approving as properly filed a petition
     seeking reorganization, arrangement, adjustment or composition of or in
     respect of the Company under any applicable Federal or State law, or
     appointing a custodian, receiver, liquidator, assignee, trustee,
     sequestrator or other similar official of the Company or of any substantial
     part of its property, or ordering the winding up or liquidation of its
     affairs, and the continuance of any such decree or order for relief or any
     such other decree or order unstayed and in effect for a period of 90
     consecutive days; or

          (6) the commencement by the Company of a voluntary case or proceeding
     under any applicable Federal or State bankruptcy, insolvency,
     reorganization or other similar law or of any other case or proceeding to
     be adjudicated a bankrupt or insolvent, or the consent by it to the entry
     of a decree or order for relief in respect of the Company in an involuntary
     case or proceeding under any applicable Federal or State bankruptcy,
     insolvency, reorganization or other similar law or to the commencement of
     any bankruptcy or insolvency case or proceeding against it, or the filing
     by it of a petition or answer or consent seeking reorganization or relief
     under any applicable Federal or State law, or the consent by it to the
     filing of such petition or to the appointment of or taking possession by a
     custodian, receiver, liquidator, assignee, trustee, sequestrator or other
     similar official of the Company or of any

                                                                            -34-

<PAGE>

     substantial part of its property, or the making by it of an assignment for
     the benefit of creditors, or the admission by it in writing of its
     inability to pay its debts generally as they become due, or the taking of
     corporate action by the Company in furtherance of any such action; or

          (7) any other Event of Default provided with respect to Securities of
     that series in the Board Resolution, supplemental indenture or Officers'
     Certificate establishing that series.

Section 5.2  Acceleration of Maturity; Rescission and Annulment.

     Unless the Board Resolution, supplemental indenture or Officers'
Certificate establishing such series provides otherwise, if an Event of Default
(other than an Event of Default specified in Section 5.1(5) or 5.1(6)) with
respect to Securities of any series at the time Outstanding occurs and is
continuing, then in every such case the Trustee or the Holders of not less than
25% in principal amount of the Outstanding Securities of that series may declare
the principal amount of all the Securities of that series (or, if any Securities
of that series are Original Issue Discount Securities, such portion of the
principal amount of such Securities as may be specified by the terms thereof),
and premium, if any, together with accrued and unpaid interest, if any, thereon,
to be due and payable immediately, by a notice in writing to the Company (and to
the Trustee if given by Holders), and upon any such declaration such principal
amount (or specified amount), and premium, if any, together with accrued and
unpaid interest, if any, thereon, shall become immediately due and payable. If
an Event of Default specified in Section 5.1(5) or 5.1(6) with respect to
Securities of any series at the time Outstanding occurs, the principal amount of
all the Securities of that series (or, if any Securities of that series are
Original Issue Discount Securities, such portion of the principal amount of such
Securities as may be specified by the terms thereof), and premium, if any,
together with accrued and unpaid interest, if any, thereon, shall automatically,
and without any declaration or other action on the part of the Trustee or any
Holder, become immediately due and payable.

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

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

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

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

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

                                                                            -35-

<PAGE>

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

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

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

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

     The Company covenants that if

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

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

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

Section 5.4  Trustee May File Proofs of Claim.

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

                                                                            -36-

<PAGE>

amount due it for the reasonable compensation, expenses, disbursements and
advances of the Trustee, its agents and counsel, and any other amounts due the
Trustee under Section 6.7.

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

Section 5.5  Trustee May Enforce Claims Without Possession of Securities.

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

Section 5.6  Application of Money Collected.

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

     FIRST: To the payment of all amounts due the Trustee under Section 6.7;

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

     THIRD: The balance, if any, to the Company or any other Person or Persons
entitled thereto.

Section 5.7  Limitation on Suits.

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

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

                                                                            -37-

<PAGE>

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

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

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

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

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

Section 5.8  Unconditional Right of Holders to Receive Principal, Premium and
Interest and to Convert.

     Notwithstanding any other provision in this Indenture, the Holder of any
Security shall have the right, which is absolute and unconditional, to receive
payment of the principal of and any premium and (subject to Section 3.7)
interest on such Security on the respective Stated Maturities expressed in such
Security (or, in the case of redemption, on the Redemption Date), to convert
such Securities in accordance with Article 14 to the extent that such right to
convert is applicable to such Security, and to institute suit for the
enforcement of any such payment, and such rights shall not be impaired without
the consent of such Holder.

Section 5.9  Restoration of Rights and Remedies.

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

Section 5.10 Rights and Remedies Cumulative.

     Except as otherwise provided with respect to the replacement or payment of
mutilated, destroyed, lost or stolen Securities in the last paragraph of Section
3.6, no right or remedy herein conferred upon or reserved to the Trustee or to
the Holders is intended to be exclusive of any other

                                                                            -38-

<PAGE>

right or remedy, and every right and remedy shall, to the extent permitted by
law, be cumulative and in addition to every other right and remedy given
hereunder or now or hereafter existing at law or in equity or otherwise. The
assertion or employment of any right or remedy hereunder, or otherwise, shall
not prevent the concurrent assertion or employment of any other appropriate
right or remedy.

Section 5.11  Delay or Omission Not Waiver.

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

Section 5.12  Control by Holders.

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

          (1) such direction shall not be in conflict with any rule of law or
     with this Indenture and the Trustee shall not have determined that the
     action so directed would be unjustly prejudicial to Holders of Securities
     of that series, or any other series, not taking part in such direction; and

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

Section 5.13  Waiver of Past Defaults.

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

          (1) a default in the payment of the principal of or any premium or
     interest on any Security of such series as and when the same shall become
     due and payable by the terms thereof, otherwise than by acceleration
     (unless such default has been cured and a sum sufficient to pay all matured
     installments of interest, principal and premium, if any, has been deposited
     with the Trustee), or

          (2) to the extent such right is applicable to such Security, a failure
     by the Company on request to convert any Security into Common Stock; or

          (3) in respect of a covenant or provision hereof which under Article 9
     cannot be modified or amended without the consent of the Holder of each
     Outstanding Security of such series affected.

                                                                            -39-

<PAGE>

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

Section 5.14  Undertaking for Costs.

     In any suit for the enforcement of any right or remedy under this
Indenture, or in any suit against the Trustee for any action taken, suffered or
omitted by it as Trustee, a court may require any party litigant in such suit to
file an undertaking to pay the costs of such suit, and may assess costs against
any such party litigant, in the manner and to the extent provided in the Trust
Indenture Act; provided that neither this Section nor the Trust Indenture Act
               -------- ----
shall be deemed to authorize any court to require such an undertaking or to make
such an assessment in any suit instituted by the Company or in any suit for the
enforcement of the right to convert any Security in accordance with Article 14.

Section 5.15  Waiver of Usury, Stay or Extension Laws.

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

                                    ARTICLE 6

                                   THE TRUSTEE

Section 6.1   Certain Duties and Responsibilities.

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

Section 6.2   Notice of Defaults.

     If a default occurs hereunder with respect to Securities of any series, the
Trustee shall give the Holders of Securities of such series notice of such
default as and to the extent provided by the Trust Indenture Act; provided,
                                                                  --------
however, that except in the case of a default in the payment of
-------

                                                                            -40-

<PAGE>

principal of (or premium, if any) or interest on any Securities of such series
or in the payment of any sinking fund installment or any conversion right
applicable to Securities of such series, the Trustee shall be protected in
withholding such notice if and so long as 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 interests of the holders of Securities of such series;
provided, further, however, that in the case of any default of the character
--------  -------  -------
specified in Section 5.1(4) with respect to Securities of such series, no such
notice to Holders shall be given until at least 60 days after the occurrence
thereof. For the purpose of this Section, the term "default" means any event
which is, or after notice or lapse of time or both would become, an Event of
Default with respect to Securities of such series.

     Except with respect to Section 10.1, the Trustee shall have no duty to
inquire as to the performance of the Company with respect to the covenants
contained in Article 10. In addition, the Trustee shall not be deemed to have
knowledge of an Event of Default except (i) any Default or Event of Default
occurring pursuant to Sections 5.1(1), 5.1(2) and 5.1(3) (defaults in payments
on the Securities) or (ii) any Default or Event of Default of which the Trustee
shall have received written notification or obtained actual knowledge.

     Delivery of reports, information and documents to the Trustee under Section
7.4 is for informational purposes only 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 hereunder (as to which the
Trustee is entitled to rely conclusively on Officers' Certificates).

Section 6.3  Certain Rights of Trustee.

     Subject to the provisions of Section 6.1:

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

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

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

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

                                                                            -41-

<PAGE>

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

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

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

Section 6.4  Not Responsible for Recitals or Issuance of Securities.

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

Section 6.5  May Hold Securities and Act as Trustee under Other Indentures.

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

     Subject to the limitations imposed by the Trust Indenture Act, nothing in
this Indenture shall prohibit the Trustee from becoming and acting as trustee
under other indentures under which other securities, or certificates of interest
of participation in other securities, of the Company are outstanding in the same
manner as if it were not Trustee hereunder.

                                                                            -42-

<PAGE>

Section 6.6  Money Held in Trust.

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

Section 6.7  Compensation and Reimbursement.

     The Company agrees:

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

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

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

     When the Trustee incurs expenses or renders services after an Event of
Default specified in Section 5.1(5) or Section 5.1(6) hereof occurs, the
expenses and the compensation for the services (including the fees and expenses
of its agents and counsel) are intended to constitute expenses of administration
under any applicable bankruptcy, insolvency, reorganization or similar law.

Section 6.8  Conflicting Interests

     If the Trustee has or shall acquire a conflicting interest within the
meaning of the Trust Indenture Act, the Trustee shall either eliminate such
interest or resign, to the extent and in the manner provided by, and subject to
the provisions of, the Trust Indenture Act and this Indenture. To the extent
permitted by the Trust Indenture Act, the Trustee shall not be deemed to have a
conflicting interest by virtue of being a trustee under this Indenture with
respect to Securities of more than one series.

Section 6.9  Corporate Trustee Required; Eligibility.

     There shall at all times be one (and only one) Trustee hereunder with
respect to the Securities of each series, which may be Trustee hereunder for
Securities of one or more other series. Each Trustee shall be a Person that is
eligible pursuant to the Trust Indenture Act to act as such and has

                                                                            -43-

<PAGE>

(or if the Trustee is a member of a bank holding company system, its bank
holding company has) a combined capital and surplus of at least $50,000,000. If
any such Person or bank holding company publishes reports of condition at least
annually, pursuant to law or to the requirements of its supervising or examining
authority, then for the purposes of this Section and to the extent permitted by
the Trust Indenture Act, the combined capital and surplus of such Person or bank
holding company shall be deemed to be its combined capital and surplus as set
forth in its most recent report of condition so published. If at any time the
Trustee with respect to the Securities of any series shall cease to be eligible
in accordance with the provisions of this Section, it shall resign immediately
in the manner and with the effect hereinafter specified in this Article.

Section 6.10 Resignation and Removal; Appointment of Successor.

     No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee in accordance with the applicable
requirements of Section 6.11.

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

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

     If at any time:

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

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

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

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

                                                                            -44-

<PAGE>

     If the Trustee shall resign, be removed or become incapable of acting, or
if a vacancy shall occur in the office of Trustee for any cause, with respect to
the Securities of one or more series, the Company, by a Board Resolution, shall
promptly appoint a successor Trustee or Trustees with respect to the Securities
of that or those series (it being understood that any such successor Trustee may
be appointed with respect to the Securities of one or more or all of such series
and that at any time there shall be only one Trustee with respect to the
Securities of any particular series) and shall comply with the applicable
requirements of Section 6.11. If, within one year after such resignation,
removal or incapability, or the occurrence of such vacancy, a successor Trustee
with respect to the Securities of any series shall be appointed by Act of the
Holders of a majority in principal amount of the Outstanding Securities of such
series delivered to the Company and the retiring Trustee, the successor Trustee
so appointed shall, forthwith upon its acceptance of such appointment in
accordance with the applicable requirements of Section 6.11, become the
successor Trustee with respect to the Securities of such series and to that
extent supersede the successor Trustee appointed by the Company. If no successor
Trustee with respect to the Securities of any series shall have been so
appointed by the Company or the Holders and accepted appointment in the manner
required by Section 6.11, the retiring Trustee may petition, or any Holder who
has been a bona fide Holder of a Security of such series for at least six months
may petition, on behalf of himself and all others similarly situated, any court
of competent jurisdiction for the appointment of a successor Trustee with
respect to the Securities of such series.

     The Company shall give notice of each resignation and each removal of the
Trustee with respect to the Securities of any series and each appointment of a
successor Trustee with respect to the Securities of any series to all Holders of
Securities of such series in the manner provided in Section 1.6. Each notice
shall include the name of the successor Trustee with respect to the Securities
of such series and the address of its Corporate Trust Office.

Section 6.11 Acceptance of Appointment by Successor.

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

     In case of the appointment hereunder of a successor Trustee with respect to
the Securities of one or more (but not all) series, the Company, the retiring
Trustee and each successor Trustee with respect to the Securities of one or more
series shall execute and deliver an indenture supplemental hereto wherein each
successor Trustee shall accept such appointment and which (1) shall contain such
provisions as shall be necessary or desirable to transfer and confirm to, and to
vest in, each

                                                                            -45-

<PAGE>

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

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

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

Section 6.12  Merger, Conversion, Consolidation or Succession to Business.

     Any corporation into which the Trustee may be merged or converted or with
which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all the corporate trust business
of the Trustee (including the administration of the trust created by this
Indenture), shall be the successor of the Trustee hereunder, provided such
corporation shall be otherwise qualified and eligible under this Article,
without the execution or filing of any paper or any further act on the part of
any of the parties hereto. In case any Securities shall have been authenticated,
but not delivered, by the Trustee then in office, any successor by merger,
conversion or consolidation to such authenticating Trustee may adopt such
authentication and deliver the Securities so authenticated with the same effect
as if such successor Trustee had itself authenticated such Securities. In the
event that any Securities shall not have been authenticated by such predecessor
Trustee, any such successor Trustee may authenticate and deliver such securities
in either its own name or that of such predecessor Trustee, with the full force
and effect which this Indenture provides the certificate of authentication of
the Trustee.

Section 6.13  Preferential Collection of Claims Against Company.

     If and when the Trustee shall be or become a creditor of the Company (or
any other obligor upon the Securities), the Trustee shall be subject to the
provisions of the Trust Indenture Act regarding the collection of claims against
the Company (or any such other obligor).

                                                                            -46-

<PAGE>

Section 6.14 Appointment of Authenticating Agent.

     The Trustee may appoint an Authenticating Agent or Agents with respect to
one or more series of Securities which shall be authorized to act on behalf of
the Trustee to authenticate Securities of such series issued upon original issue
and upon exchange, registration of transfer or partial redemption thereof or
pursuant to Section 3.6, and Securities so authenticated shall be entitled to
the benefits of this Indenture and shall be valid and obligatory for all
purposes as if authenticated by the Trustee hereunder. Wherever reference is
made in this Indenture to the authentication and delivery of Securities by the
Trustee or the Trustee's certificate of authentication, such reference shall be
deemed to include authentication and delivery on behalf of the Trustee by an
Authenticating Agent and a certificate of authentication executed on behalf of
the Trustee by an Authenticating Agent. Each Authenticating Agent shall be
acceptable to the Company and shall at all times be a corporation organized and
doing business under the laws of the United States of America, any state thereof
or the District of Columbia, authorized under such laws to act as Authenticating
Agent, having (or if the Authenticating Agent is a member of a bank holding
company system, its bank holding company has) a combined capital and surplus of
not less than $50,000,000 and subject to supervision or examination by federal
or state authority. If such Authenticating Agent publishes reports of condition
at least annually, pursuant to law or to the requirements of said supervising or
examining authority, then for the purposes of this Section, the combined capital
and surplus of such Authenticating Agent shall be deemed to be its combined
capital and surplus as set forth in its most recent report of condition so
published. If at any time an Authenticating Agent shall cease to be eligible in
accordance with the provisions of this Section, such Authenticating Agent shall
resign immediately in the manner and with the effect specified in this Section.

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

     An Authenticating Agent may resign at any time by giving written notice
thereof to the Trustee and to the Company. The Trustee may at any time terminate
the agency of an Authenticating Agent by giving written notice thereof to such
Authenticating Agent and to the Company. Upon receiving such a notice of
resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent which shall be acceptable to the Company and shall give notice of such
appointment in the manner provided in Section 1.6 to all Holders of Securities
of the series with respect to which such Authenticating Agent will serve. Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, with like effect as if originally named as an Authenticating Agent.
No successor Authenticating Agent shall be appointed unless eligible under the
provisions of this Section.

                                                                            -47-

<PAGE>

     The Trustee agrees to pay to each Authenticating Agent from time to time
reasonable compensation for its services under this Section, and the Trustee
shall be entitled to be reimbursed for such payments, subject to the provisions
of Section 6.7.

     If an appointment with respect to one or more series is made pursuant to
this Section 6.12, the Securities of such series may have endorsed thereon, in
lieu of the Trustee's certificate of authentication, an alternative
certificate of authentication in the following form:

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

                                        U.S. Bank National Association,
                                        as Trustee

                                        By: __________________________________
                                                 as Authenticating Agent

                                        By: __________________________________
                                                   Authorized Officer

                                    ARTICLE 7

                HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

Section 7.1 Company to Furnish Trustee Names and Addresses of Holders.

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

          (1) semi-annually, not later than 15 days after the Regular Record
     Date, for each respective series of Securities, a list, in such form as the
     Trustee may reasonably require, of the names and addresses of the Holders
     of Securities of each series as of such Regular Record Date, as the case
     may be, or if there is no Regular Record Date for such series of
     Securities, semi-annually and

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

provided that no such list need be furnished by the Company to the Trustee so
--------
long as the Trustee is acting as Security Registrar.

Section 7.2 Preservation of Information; Communications to Holders.

     The Trustee shall preserve, in as current a form as is reasonably
practicable, the names and addresses of Holders contained in the most recent
list furnished to the Trustee as provided in

                                                                            -48-

<PAGE>

Section 7.1 and the names and addresses of Holders received by the Trustee in
its capacity as Security Registrar. The Trustee may destroy any list furnished
to it as provided in Section 7.1 upon receipt of a new list so furnished.

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

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

Section 7.3 Reports by Trustee.

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

     Reports so required to be transmitted at stated intervals of not more than
12 months shall be transmitted no later than July 15 in each calendar year,
commencing with the first July 15 after the first issuance of Securities
pursuant to this Indenture.

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

Section 7.4 Reports by Company.

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

                                                                            -49-

<PAGE>

                                    ARTICLE 8

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

Section 8.1 Company May Consolidate, etc. , Only on Certain Terms.

     The Company shall not consolidate with or merge into any other Person (in a
transaction in which the Company is not the surviving corporation) or convey,
transfer or lease its properties and assets substantially as an entirety to any
Person, unless:

          (1) in case the Company shall consolidate with or merge into another
     Person (in a transaction in which the Company is not the surviving
     corporation) or convey, transfer or lease its properties and assets
     substantially as an entirety to any Person, the Person formed by such
     consolidation or into which the Company is merged or the Person which
     acquires by conveyance or transfer, or which leases, the properties and
     assets of the Company substantially as an entirety shall be a corporation,
     limited liability company, partnership or trust, shall be organized and
     validly existing under the laws of the United States of America, any state
     thereof or the District of Columbia and shall expressly assume, by an
     indenture supplemental hereto, executed and delivered to the Trustee, in
     form satisfactory to the Trustee, the due and punctual payment of the
     principal of and any premium and interest on all the Securities and the
     performance or observance of every covenant of this Indenture on the part
     of the Company to be performed or observed, and the conversion rights shall
     be provided for in accordance with Article 14, if applicable, or as
     otherwise specified pursuant to Section 3.1, by supplemental indenture
     satisfactory in form to the Trustee, executed and delivered to the Trustee,
     by the Person (if other than the Company) formed by such consolidation or
     into which the Company shall have been merged or by the Person which shall
     have acquired the Company's assets;

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

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

Section 8.2 Successor Substituted.

     Upon any consolidation of the Company with, or merger of the Company into,
any other Person or any conveyance, transfer or lease of the properties and
assets of the Company substantially

                                                                            -50-

<PAGE>

as an entirety in accordance with Section 8.1, the successor Person formed by
such consolidation or into which the Company is merged or to which such
conveyance, transfer or lease is made shall succeed to, and be substituted for,
and may exercise every right and power of, the Company under this Indenture with
the same effect as if such successor Person had been named as the Company
herein, and thereafter, except in the case of a lease, the predecessor Person
shall be relieved of all obligations and covenants under this Indenture and the
Securities.

                                    ARTICLE 9

                             SUPPLEMENTAL INDENTURES

Section 9.1 Supplemental Indentures Without Consent of Holders.

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

          (1) to evidence the succession of another Person to the Company, or
     successive successions, and the assumption by any such successor of the
     covenants of the Company herein and in the Securities in compliance with
     Article 8; or

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

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

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

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

          (6) to secure the Securities, including provisions regarding the
     circumstances under which collateral may be released or substituted; or

          (7) to add or provide for guaranties of the Securities or additional
     obligors on the Securities; or

                                                                            -51-

<PAGE>

          (8)  to establish the form or terms of Securities of any series as
     permitted by Sections 2.1 and 3.1; or

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

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

          (11) to supplement any of the provisions of the Indenture to such
     extent as shall be necessary to permit or facilitate the defeasance and
     discharge of any series of Securities pursuant to Articles 4 and 13,
     provided that any such action shall not adversely affect the interests of
     --------
     the Holders of Securities of such series or any other series of Securities
     in any material respect.

Section 9.2 Supplemental Indentures with Consent of Holders.

     With the consent of the Holders of a majority in principal amount of the
Outstanding Securities of each series affected by such supplemental indenture,
by Act of said Holders delivered to the Company and the Trustee, the Company,
when authorized by a Board Resolution, and the Trustee may enter into an
indenture or indentures supplemental hereto for the purpose of adding any
provisions to or changing in any manner or eliminating any of the provisions of
this Indenture or of modifying in any manner the rights of the Holders of
Securities of such series under this Indenture; provided, however, that no such
                                                --------  -------
supplemental indenture shall, without the consent of the Holder of each
Outstanding Security affected thereby,

          (1) change the Stated Maturity of the principal of, or any installment
     of principal of or interest on, any Security, or reduce the principal
     amount thereof or the rate of interest thereon or any premium payable upon
     the redemption thereof, or reduce the amount of the principal of an
     Original Issue Discount Security or any other Security which would be due
     and payable upon a declaration of acceleration of the Maturity thereof
     pursuant to Section 5.2, or change the coin or currency in which, any
     Security or any premium or interest thereon is payable, or impair the right
     to institute suit for) the enforcement of any such payment on or after the
     Stated Maturity thereof (or, in the case of redemption, on or after the
     Redemption Date), or modify the provisions of this Indenture

                                                                            -52-

<PAGE>

     in the case of Securities of any series that are convertible into or other
     securities of the Company, adversely affect the right of Holders to convert
     any of the Securities of such series other than as provided in or pursuant
     to this Indenture, or

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

          (3) modify any of the provisions of this Section, Section 5.13 or
     Section 10.8, except to increase any such percentage or to provide that
     certain other provisions of this Indenture cannot be modified or waived
     without the consent of the Holder of each Outstanding Security affected
     thereby; provided, however, that this clause shall not be deemed to require
              --------  -------
     the consent of any Holder with respect to changes in the references to "the
     Trustee" and concomitant changes in this Section and Section 10.8, or the
     deletion of this proviso, in accordance with the requirements of Sections
     6.11 and 9.1(8), or

          (4) if applicable, make any change that adversely affects the right to
     convert any security as provided in Article 14 or pursuant to Section 3.1
     (except as permitted by Section 9.1(9)) or decrease the conversion rate or
     increase the conversion price of any such security.

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

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

Section 9.3 Execution of Supplemental Indentures.

     In executing, or accepting the additional trusts created by, any
supplemental indenture permitted by this Article or the modifications thereby of
the trusts created by this Indenture, the Trustee shall be entitled to receive,
and (subject to Sections 6.1 and 6.3) shall be fully protected in relying upon,
an Opinion of Counsel stating that the execution of such supplemental indenture
is authorized or permitted by this Indenture. The Trustee may, but shall not be
obligated to, enter into any such supplemental indenture which affects the
Trustee's own rights, duties or immunities under this Indenture or otherwise.

                                                                            -53-

<PAGE>

Section 9.4  Effect of Supplemental Indentures.

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

Section 9.5  Conformity with Trust Indenture Act.

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

Section 9.6  Reference in Securities to Supplemental Indentures.

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

                                   ARTICLE 10

                                    COVENANTS

Section 10.1 Payment of Principal, Premium and Interest.

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

Section 10.2 Maintenance of Office or Agency.

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

                                                                            -54-

<PAGE>

notices and demands. Unless otherwise provided in a supplemental indenture or
pursuant to Section 3.1 hereof, the Place of Payment for any series of
Securities shall be the Corporate Trust Office of the Trustee.

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

Section 10.3 Money for Securities Payments To Be Held in Trust.

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

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

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

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

     Any money deposited with the Trustee or any Paying Agent, or then held by
the Company, in trust for the payment of the principal of or any premium or
interest on any Security of any series and

                                                                            -55-

<PAGE>

remaining unclaimed for a period ending on the earlier of the date that is ten
Business Days prior to the date such money would escheat to the state or two
years after such principal, premium or interest has become due and payable shall
be paid to the Company on Company Request, or (if then held by the Company)
shall be discharged from such trust; and the Holder of such Security shall
thereafter, as an unsecured general creditor, look only to the Company for
payment thereof, and all liability of the Trustee or such Paying Agent with
respect to such trust money, and all liability of the Company as trustee
thereof, shall thereupon cease; provided, however, that the Trustee or such
                                --------  -------
Paying Agent, before being required to make any such repayment, may at the
expense of the Company cause to be published once, in a newspaper published in
the English language, customarily published on each Business Day and of general
circulation in each Place of Payment, notice that such money remains unclaimed
and that, after a date specified therein, which shall not be less than 30 days
from the date of such publication, any unclaimed balance of such money then
remaining will be repaid to the Company.

Section 10.4 Statement by Officers as to Default.

     The Company will deliver to the Trustee, within 120 days after the end of
each fiscal year of the Company ending after the date hereof, an Officers'
Certificate, stating whether or not to the best knowledge of the signers thereof
the Company is in default in the performance and observance of any of the terms,
provisions and conditions of this Indenture (without regard to any period of
grace or requirement of notice provided hereunder) and, if the Company shall be
in default, specifying all such defaults and the nature and status thereof of
which they may have knowledge. The fiscal year of the Company currently ends on
December 31; and the Company will give the Trustee prompt written notice of any
change of its fiscal year.

Section 10.5 Existence.

     Subject to Article 8, the Company will do or cause to be done all things
necessary to preserve and keep in full force and effect its existence.

Section 10.6 Maintenance of Properties.

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

                                                                            -56-

<PAGE>

Section 10.7  Payment of Taxes and Other Claims.

     The Company will pay or discharge or cause to be paid or discharged, before
the same shall become delinquent, (1) all taxes, assessments and governmental
charges levied or imposed upon the Company or upon the income, profits or
property of the Company, and (2) all lawful claims for labor, materials and
supplies which, if unpaid, might by law become a lien upon the property of the
Company; provided, however, that the Company shall not be required to pay or
         --------  -------
discharge or cause to be paid or discharged any such tax, assessment, charge or
claim (i) whose amount, applicability or validity is being contested in good
faith by appropriate proceedings or (ii) if the failure to pay or discharge
would not have a material adverse effect on the assets, business, operations,
properties or condition (financial or otherwise) of the Company and its
subsidiaries, taken as a whole.

Section 10.8  Waiver of Certain Covenants.

     Except as otherwise specified as contemplated by Section 3.1 for Securities
of such series, the Company may, with respect to the Securities of any series,
omit in any particular instance to comply with any term, provision or condition
set forth in any covenant provided pursuant to Section 3.1(19), 9.1(2), 9.1(7),
10.6 or 10.7 for the benefit of the Holders of such series if before the time
for such compliance the Holders of at least a majority in principal amount of
the Outstanding Securities of such series shall, by Act of such Holders, either
waive such compliance in such instance or generally waive compliance with such
term, provision or condition, but no such waiver shall extend to or affect such
term, provision or condition except to the extent so expressly waived, and,
until such waiver shall become effective, the obligations of the Company and the
duties of the Trustee in respect of any such term, provision or condition shall
remain in full force and effect.

                                   ARTICLE 11

                            REDEMPTION OF SECURITIES

Section 11.1  Applicability of Article.

     Securities of any series which are redeemable before their Stated Maturity
shall be redeemable in accordance with their terms and (except as otherwise
specified as contemplated by Section 3.1 for such Securities) in accordance with
this Article.

Section 11.2  Election to Redeem; Notice to Trustee.

     The election of the Company to redeem any Securities shall be evidenced by
a Board Resolution or in another manner specified as contemplated by Section 3.1
for such Securities. In case of any redemption at the election of the Company of
less than all the Securities of any series (including any such redemption
affecting only a single Security), the Company shall, at least 45 days prior to
the Redemption Date fixed by the Company (unless a shorter notice shall be
satisfactory to the Trustee), notify the Trustee of such Redemption Date, of the
principal amount of Securities of such series to be redeemed and, if applicable,
of the tenor of the Securities to be redeemed. In the

                                                                            -57-

<PAGE>

case of any redemption of Securities prior to the expiration of any restriction
on such redemption provided in the terms of such Securities or elsewhere in this
Indenture, the Company shall furnish the Trustee with an Officers' Certificate
evidencing compliance with such restriction.

Section 11.3   Selection by Trustee of Securities to Be Redeemed.

     If less than all the Securities of any series are to be redeemed (unless
all the Securities of such series and of a specified tenor are to be redeemed or
unless such redemption affects only a single Security), the particular
Securities to be redeemed shall be selected not more than 45 days prior to the
Redemption Date by the Trustee, from the Outstanding Securities of such series
not previously called for redemption, by lot, or in the Trustee's discretion, on
a pro-rata basis, provided that the unredeemed portion of the principal amount
of any Security shall be in an authorized denomination (which shall not be less
than the minimum authorized denomination) for such Security. If less than all
the Securities of such series and of a specified tenor are to be redeemed
(unless such redemption affects only a single Security), the particular
Securities to be redeemed shall be selected not more than 45 days prior to the
Redemption Date by the Trustee, from the Outstanding Securities of such series
and specified tenor not previously called for redemption in accordance with the
preceding sentence.

     If any Security selected for partial redemption is converted in part before
termination of the conversion right with respect to the portion of the Security
so selected, the converted portion of such Security shall be deemed (so far as
may be) to be the portion selected for redemption. Securities which have been
converted during a selection of Securities to be redeemed shall be treated by
the Trustee as Outstanding for the purpose of such selection.

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

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

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

Section 11.4   Notice of Redemption.

     Notice of redemption shall be given by first-class mail, postage prepaid,
mailed not fewer than 30 nor more than 60 days prior to the Redemption Date,
unless a shorter period is specified in

                                                                            -58-

<PAGE>

the Securities to be redeemed, to each Holder of Securities to be redeemed, at
its address appearing in the Security Register.

     All notices of redemption shall state:

          (1) the Redemption Date,

          (2) the Redemption Price (including accrued interest, if any),

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

          (4) in case any Security is to be redeemed in part only, that on and
     after the Redemption Date, upon surrender of such Security, the Holder of
     such Security will receive, without charge, a new Security or Securities of
     authorized denominations for the principal amount thereof remaining
     unredeemed;

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

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

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

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

          (9) the CUSIP number or numbers and/or common code(s) of the Security
     being redeemed.

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

Section 11.5   Deposit of Redemption Price.

     On or prior to any Redemption Date, the Company shall deposit with the
Trustee or with a Paying Agent (or, if the Company is acting as its own Paying
Agent, segregate and hold in trust as provided in Section 10.3) an amount of
money sufficient to pay the Redemption Price of, and (except if the Redemption
Date shall be an Interest Payment Date) accrued interest on, all the Securities
which are to be redeemed on that date.

     If any Security called for redemption is converted, any money deposited
with the Trustee or with a Paying Agent or so segregated and held in trust for
the redemption of such Security shall (subject to the right of any Holder of
such Security to receive interest as provided in the last

                                                                            -59-

<PAGE>

paragraph of Section 3.7) be paid to the Company on Company Request, or if then
held by the Company, shall be discharged from such trust.

Section 11.6   Securities Payable on Redemption Date.

     Notice of redemption having been given as aforesaid, the Securities so to
be redeemed shall, on the Redemption Date, become due and payable at the
Redemption Price therein specified, and from and after such date (unless the
Company shall default in the payment of the Redemption Price and accrued
interest) such Securities shall cease to bear interest. Upon surrender of any
such Security for redemption in accordance with said notice, such Security shall
be paid by the Company at the Redemption Price, together with accrued interest
to the Redemption Date; provided, however, that, unless otherwise specified as
contemplated by Section 3.1, installments of interest whose Stated Maturity is
on or prior to the Redemption Date will be payable to the Holders of such
Securities, or one or more Predecessor Securities, registered as such at the
close of business on the relevant Record Dates according to their terms and the
provisions of Section 3.7.

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

Section 11.7   Securities Redeemed in Part.

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

                                   ARTICLE 12

                                  SINKING FUNDS

Section 12.1   Applicability of Article.

     The provisions of this Article shall be applicable to any sinking fund for
the retirement of Securities of any series except as otherwise specified as
contemplated by Section 3.1 for such Securities.

     The minimum amount of any sinking fund payment provided for by the terms of
any Securities is herein referred to as a "mandatory sinking fund payment," and
any payment in excess of such minimum amount provided for by the terms of such
Securities is herein referred to as an

                                                                            -60-

<PAGE>

"optional sinking fund payment." If provided for by the terms of any Securities,
the cash amount of any sinking fund payment may be subject to reduction as
provided in Section 12.2. Each sinking fund payment shall be applied to the
redemption of Securities as provided for by the terms of such Securities.

Section 12.2   Satisfaction of Sinking Fund Payments with Securities.

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

Section 12.3   Redemption of Securities for Sinking Fund.

     Not fewer than 60 days prior to each sinking fund payment date for any
Securities, the Company will deliver to the Trustee an Officers' Certificate
specifying the amount of the next ensuing sinking fund payment for such
Securities pursuant to the terms of such Securities, the portion thereof, if
any, which is to be satisfied by payment of cash and the portion thereof, if
any, which is to be satisfied by delivering and crediting Securities pursuant to
Section 12.2 and will also deliver to the Trustee any Securities to be so
delivered. Not fewer than 30 days prior to each such sinking fund payment date,
the Trustee shall select the Securities to be redeemed upon such sinking fund
payment date in the manner specified in Section 11.3 and cause notice of the
redemption thereof to be given in the name of and at the expense of the Company
in the manner provided in Section 11.4. Such notice having been duly given, the
redemption of such Securities shall be made upon the terms and in the manner
stated in Sections 11.6 and 11.7.

                                   ARTICLE 13

                       DEFEASANCE AND COVENANT DEFEASANCE

Section 13.1   Company's Option to Effect Defeasance or Covenant Defeasance.

     The Company may elect, at its option at any time, to have Section 13.2 or
Section 13.3 applied to any Securities or any series of Securities, as the case
may be, designated pursuant to Section 3.1 as being defeasible pursuant to such
Section 13.2 or 13.3, in accordance with any applicable requirements provided
pursuant to Section 3.1 and upon compliance with the conditions

                                                                            -61-

<PAGE>

set forth below in this Article. Any such election shall be evidenced by a Board
Resolution or in another manner specified as contemplated by Section 3.1 for
such Securities.

Section 13.2   Defeasance and Discharge.

     Upon the Company's exercise of its option (if any) to have this Section
applied to any Securities or any series of Securities, as the case may be, the
Company shall be deemed to have been discharged from its obligations with
respect to such Securities as provided in this Section on and after the date the
conditions set forth in Section 13.4 are satisfied (hereinafter called
"Defeasance"). For this purpose, such Defeasance means that the Company shall be
deemed to have paid and discharged the entire indebtedness represented by such
Securities and to have satisfied all its other obligations under such Securities
and this Indenture insofar as such Securities are concerned (and the Trustee, at
the expense of the Company, shall execute proper instruments acknowledging the
same), subject to the following which shall survive until otherwise terminated
or discharged hereunder:

          (1) the rights of Holders of such Securities to receive, solely from
     the trust fund described in Section 13.4 and as more fully set forth in
     such Section, payments in respect of the principal of and any premium and
     interest on such Securities when payments are due,

          (2) the Company's obligations with respect to such Securities under
     Sections 3.4, 3.5, 3.6, 10.2 and 10.3, and, if applicable, Article 14,

          (3) the rights, powers, trusts, duties and immunities of the Trustee
     hereunder, and

          (4) this Article.

     Subject to compliance with this Article, the Company may exercise its
option (if any) to have this Section applied to any Securities notwithstanding
the prior exercise of its option (if any) to have Section 13.3 applied to such
Securities.

Section 13.3   Covenant Defeasance.

     Upon the Company's exercise of its option (if any) to have this Section
applied to any Securities or any series of Securities, as the case may be,

          (1) the Company shall be released from its obligations under Sections
     10.6 and 10.7 and any covenants provided pursuant to Sections 3.1(19),
     9.1(2) or 9.1(7) or for the benefit of the Holders of such Securities and

          (2) the occurrence of any event specified in Section 5.1(4) (with
     respect to any of Sections 10.6 and 10.7 and any such covenants provided
     pursuant to Section 3.1(19), 9.1(2) or 9.1(7), and the occurrence of any
     other Event of Default specified pursuant to Section 3.1,) shall be deemed
     not to be or result in an Event of Default,

in each case with respect to such Securities or any series of Securities as
provided in this Section on and after the date the conditions set forth in
Section 13.4 are satisfied (hereinafter called "Covenant

                                                                            -62-

<PAGE>

Defeasance"). For this purpose, such Covenant Defeasance means that, with
respect to such Securities, the Company may omit to comply with and shall have
no liability in respect of any term, condition or limitation set forth in any
such specified Section (to the extent so specified in the case of Section
5.1(4)) and the occurrence of any Event of Default specified pursuant to
Section 3.1, whether directly or indirectly by reason of any reference elsewhere
herein to any such Section or by reason of any reference in any such Section to
any other provision herein or in any other document, but the remainder of this
Indenture and such Securities shall be unaffected thereby.

Section 13.4   Conditions to Defeasance or Covenant Defeasance.

     The following shall be the conditions to the application of Section 13.2 or
Section 13.3 to any Securities or any series of Securities, as the case may be:

          (1) The Company shall irrevocably have deposited or caused to be
     deposited with the Trustee (or another trustee which satisfies the
     requirements contemplated by Section 6.9 and agrees to comply with the
     provisions of this Article applicable to it) as trust funds in trust for
     the purpose of making the following payments, specifically pledged as
     security for, and dedicated solely to, the benefits of the Holders of such
     Securities,

              (A) in the case of Securities of a series denominated in currency
          of the United States of America,

                  (i)   cash in currency of the United States of America in an
               amount, or

                  (ii)  U.S. Government Obligations which through the scheduled
               payment of principal and interest in respect thereof in
               accordance with their terms will provide, not later than one day
               before the due date of any payment, an amount in cash, or

                  (iii) a combination thereof, or

              (B) in the case of Securities of a series denominated in currency
          other than that of the United States of America,

                  (i)   cash in the currency in which such series of Securities
               is denominated in an amount, or

                  (ii)  Foreign Government Obligations which through the
               scheduled payment of principal and interest in respect thereof in
               accordance with their terms will provide, not later than one day
               before the due date of any payment, an amount in cash, or

                  (iii) a combination thereof,
                                                                            -63-

<PAGE>

     in each case sufficient, in the opinion of a nationally recognized firm of
     independent public accountants expressed in a written certification thereof
     delivered to the Trustee, to pay and discharge, and which shall be applied
     by the Trustee (or any such other qualifying trustee) to pay and discharge,
     the principal of and any premium and interest on such Securities on the
     respective Stated Maturities, in accordance with the terms of this
     Indenture and such Securities.

          (2) In the event of an election to have Section 13.2 apply to any
     Securities or any series of Securities, as the case may be, the Company
     shall have delivered to the Trustee an Opinion of Counsel stating that (A)
     the Company has received from, or there has been published by, the Internal
     Revenue Service a ruling or (B) since the date of this instrument, there
     has been a change in the applicable Federal income tax law, in either case
     (A) or (B) to the effect that, and based thereon such opinion shall confirm
     that, the Holders of such Securities will not recognize gain or loss for
     federal income tax purposes as a result of the deposit, Defeasance and
     discharge to be effected with respect to such Securities and will be
     subject to federal income tax on the same amount, in the same manner and at
     the same times as would be the case if such deposit, Defeasance and
     discharge were not to occur.

          (3) In the event of an election to have Section 13.3 apply to any
     Securities or any series of Securities, as the case may be, the Company
     shall have delivered to the Trustee an Opinion of Counsel to the effect
     that the Holders of such Securities will not recognize gain or loss for
     federal income tax purposes as a result of the deposit and Covenant
     Defeasance to be effected with respect to such Securities and will be
     subject to federal income tax on the same amount, in the same manner and at
     the same times as would be the case if such deposit and Covenant Defeasance
     were not to occur.

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

          (5) No event which is, or after notice or lapse of time or both would
     become, an Event of Default with respect to such Securities or any other
     Securities shall have occurred and be continuing at the time of such
     deposit or, with regard to any such event specified in Sections 5.1(5) and
     (6), at any time on or prior to the 90th day after the date of such deposit
     (it being understood that this condition shall not be deemed satisfied
     until after such 90th day).

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

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

                                                                            -64-

<PAGE>

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

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

Section 13.5 Deposited Money, U. S. Government Obligations and Foreign
Government Obligations to be Held in Trust; Miscellaneous Provisions.

     Subject to the provisions of the last paragraph of Section 10.3, all money,
U.S. Government Obligations and Foreign Government Obligations (including the
proceeds thereof) deposited with the Trustee or other qualifying trustee (solely
for purposes of this Section and Section 13.6, the Trustee and any such other
trustee are referred to collectively as the "Trustee") pursuant to Section 13.4
in respect of any Securities shall be held in trust and applied by the Trustee,
in accordance with the provisions of such Securities and this Indenture, to the
payment, either directly or through any such Paying Agent (including the Company
acting as its own Paying Agent) as the Trustee may determine, to the Holders of
such Securities, of all sums due and to become due thereon in respect of
principal and any premium and interest, but money so held in trust need not be
segregated from other funds except to the extent required by law. The Company
shall pay and indemnify the Trustee against any tax, fee or other charge imposed
on or assessed against the U.S. Government Obligations or Foreign Government
Obligations deposited pursuant to Section 13.4 or the principal and interest
received in respect thereof other than any such tax, fee or other charge which
by law is for the account of the Holders of Outstanding Securities. Anything in
this Article to the contrary notwithstanding, the Trustee shall deliver or pay
to the Company from time to time upon Company Request any money, U.S. Government
Obligations or Foreign Government Obligations held by it as provided in Section
13.4 with respect to any Securities which, in the opinion of a nationally
recognized firm of independent public accountants expressed in a written
certification thereof delivered to the Trustee, are in excess of the amount
thereof which would then be required to be deposited to effect the Defeasance or
Covenant Defeasance, as the case may be, with respect to such Securities.

Section 13.6   Reinstatement.

     If the Trustee or the Paying Agent is unable to apply any money in
accordance with this Article with respect to any Securities by reason of any
order or judgment of any court or governmental authority enjoining, restraining
or otherwise prohibiting such application, then the obligations under this
Indenture and such Securities from which the Company has been discharged or
released pursuant to Section 13.2 or 13.3 shall be revived and reinstated as
though no deposit had occurred pursuant to this Article with respect to such
Securities, until such time as the Trustee or Paying Agent is permitted to apply
all money held in trust pursuant to Section 13.5 with respect to such Securities
in accordance with this Article; provided, however, that if the Company makes
                                 --------  -------
any payment of principal of or any premium or interest on any such Security
following such

                                                                            -65-

<PAGE>

reinstatement of its obligations, the Company shall be subrogated to the rights
(if any) of the Holders of such Securities to receive such payment from the
money so held in trust.

                                   ARTICLE 14

                            CONVERSION OF SECURITIES

Section 14.1   Applicability of Article.

     The provisions of this Article shall be applicable to the Securities of any
series which are convertible into shares of Common Stock of the Company, and the
issuance of such shares of Common Stock upon the conversion of such Securities,
except as otherwise specified as contemplated by Section 3.1 for the Securities
of such series.

Section 14.2   Exercise of Conversion Privilege.

     In order to exercise a conversion privilege, the Holder of a Security of a
series with such a privilege shall surrender such Security to the Company at the
office or agency maintained for that purpose pursuant to Section 10.2,
accompanied by a duly executed conversion notice to the Company substantially in
the form set forth in Section 2.6 stating that the Holder elects to convert such
Security or a specified portion thereof. Such notice shall also state, if
different from the name and address of such Holder, the name or names (with
address) in which the certificate or certificates for shares of Common Stock
which shall be issuable on such conversion shall be issued. Securities
surrendered for conversion shall (if so required by the Company or the Trustee)
be duly endorsed by or accompanied by instruments of transfer in forms
satisfactory to the Company and the Trustee duly executed by the Holder or its
attorney duly authorized in writing; and Securities so surrendered for
conversion (in whole or in part) during the period from the close of business on
any Regular Record Date to the opening of business on the next succeeding
Interest Payment Date (excluding Securities or portions thereof called for
redemption during the period beginning at the close of business on a Regular
Record Date and ending at the opening of business on the first Business Day
after the next succeeding Interest Payment Date, or if such Interest Payment
Date is not a Business Day, the second such Business Day) shall also be
accompanied by payment in funds acceptable to the Company of an amount equal to
the interest payable on such Interest Payment Date on the principal amount of
such Security then being converted, and such interest shall be payable to such
Holder notwithstanding the conversion of such Security, subject to the
provisions of Section 3.7 relating to the payment of Defaulted Interest by the
Company. As promptly as practicable after the receipt of such notice and of any
payment required pursuant to a Board Resolution and, subject to Section 3.3, set
forth, or determined in the manner provided, in an Officers' Certificate, or
established in one or more indentures supplemental hereto setting forth the
terms of such series of Security, and the surrender of such Security in
accordance with such reasonable regulations as the Company may prescribe, the
Company shall issue and shall deliver, at the office or agency at which such
Security is surrendered, to such Holder or on its written order, a certificate
or certificates for the number of full shares of Common Stock issuable upon the
conversion of such Security (or specified portion thereof), in accordance with
the provisions of such

                                                                            -66-

<PAGE>

Board Resolution, Officers' Certificate or supplemental indenture, and cash as
provided therein in respect of any fractional share of such Common Stock
otherwise issuable upon such conversion. Such conversion shall be deemed to have
been effected immediately prior to the close of business on the date on which
such notice and such payment, if required, shall have been received in proper
order for conversion by the Company and such Security shall have been
surrendered as aforesaid (unless such Holder shall have so surrendered such
Security and shall have instructed the Company to effect the conversion on a
particular date following such surrender and such Holder shall be entitled to
convert such Security on such date, in which case such conversion shall be
deemed to be effected immediately prior to the close of business on such date)
and at such time the rights of the Holder of such Security as such Security
Holder shall cease and the person or persons in whose name or names any
certificate or certificates for shares of Common Stock of the Company shall be
issuable upon such conversion shall be deemed to have become the Holder or
Holders of record of the shares represented thereby. Except as set forth above
and subject to the final paragraph of Section 3.7, no payment or adjustment
shall be made upon any conversion on account of any interest accrued on the
Securities (or any part thereof) surrendered for conversion or on account of any
dividends on the Common Stock of the Company issued upon such conversion. In the
case of any Security which is converted in part only, upon such conversion the
Company shall execute and the Trustee shall authenticate and deliver to or on
the order of the Holder thereof, at the expense of the Company, a new Security
or Securities of the same series, of authorized denominations, in aggregate
principal amount equal to the unconverted portion of such Security.

Section 14.3   No Fractional Shares.

     No fractional share of Common Stock of the Company shall be issued upon
conversions of Securities of any series. If more than one Security shall be
surrendered for conversion at one time by the same Holder, the number of full
shares which shall be issuable upon conversion shall be computed on the basis of
the aggregate principal amount of the Securities (or specified portions thereof
to the extent permitted hereby) so surrendered. If, except for the provisions of
this Section 14.3, any Holder of a Security or Securities would be entitled to a
fractional share of Common Stock of the Company upon the conversion of such
Security or Securities, or specified portions thereof, the Company shall pay to
such Holder an amount in cash equal to the current market value of such
fractional share computed, (i) if such Common Stock is listed or admitted to
unlisted trading privileges on a national securities exchange or market, on the
basis of the last reported sale price regular way on such exchange or market on
the last trading day prior to the date of conversion upon which such a sale
shall have been effected, or (ii) if such Common Stock is not at the time so
listed or admitted to unlisted trading privileges on a national securities
exchange or market, on the basis of the average of the bid and asked prices of
such Common Stock in the over-the-counter market, on the last trading day prior
to the date of conversion, as reported by the National Quotation Bureau,
Incorporated or similar organization if the National Quotation Bureau,
Incorporated is no longer reporting such information, or if not so available,
the fair market price as determined by the Board of Directors. For purposes of
this Section, "trading day" shall mean each Monday, Tuesday, Wednesday, Thursday
and Friday other than any day on which the Common Stock is not traded on the
Nasdaq National Market, or if the Common Stock is not traded on the

                                                                            -67-

<PAGE>

Nasdaq National Market, on the principal exchange or market on which the Common
Stock is traded or quoted.

Section 14.4   Adjustment of Conversion Price.

     The conversion price of Securities of any series that is convertible into
Common Stock of the Company shall be adjusted for any stock dividends, stock
splits, reclassifications, combinations or similar transactions in accordance
with the terms of the supplemental indenture or Board Resolutions setting forth
the terms of the Securities of such series. Whenever the conversion price is
adjusted, the Company shall compute the adjusted conversion price in accordance
with terms of the applicable Board Resolution or supplemental indenture and
shall prepare an Officers' Certificate setting forth the adjusted conversion
price and showing in reasonable detail the facts upon which such adjustment is
based, and such certificate shall forthwith be filed at each office or agency
maintained for the purpose of conversion of Securities pursuant to Section 10.2
and, if different, with the Trustee. The Company shall forthwith cause a notice
setting forth the adjusted conversion price to be mailed, first class postage
prepaid, to each Holder of Securities of such series at its address appearing on
the Security Register and to any conversion agent other than the Trustee.

Section 14.5   Notice of Certain Corporate Actions.

     In case:

          (1) the Company shall declare a dividend (or any other distribution)
     on its Common Stock payable otherwise than in cash out of its retained
     earnings (other than a dividend for which approval of any shareholders of
     the Company is required) that would require an adjustment pursuant to
     Section 14.4; or

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

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

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

then the Company shall cause to be filed with the Trustee, and shall cause to be
mailed to all Holders at their last addresses as they shall appear in the
Security Register, at least 20 days (or 10 days in any case specified in clause
(1) or (2) above) prior to the applicable record date hereinafter specified, a
notice stating (i) the date on which a record is to be taken for the purpose of
such dividend,

                                                                            -68-

<PAGE>

distribution, rights, options or warrants, or, if a record is not to be taken,
the date as of which the holders of Common Stock of record to be entitled to
such dividend, distribution, rights, options or warrants are to be determined,
or (ii) the date on which such reclassification, consolidation, merger, share
exchange, sale, dissolution, liquidation or winding up is expected to become
effective, and the date as of which it is expected that holders of Common Stock
of record shall be entitled to exchange their shares of Common Stock for
securities, cash or other property deliverable upon such reclassification,
consolidation, merger, share exchange, sale, dissolution, liquidation or winding
up. If at any time the Trustee shall not be the conversion agent, a copy of such
notice shall also forthwith be filed by the Company with the Trustee.

Section 14.6   Reservation of Shares of Common Stock.

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

Section 14.7   Payment of Certain Taxes upon Conversion.

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

Section 14.8   Nonassessability.

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

Section 14.9   Provision in Case of Consolidation, Merger or Sale of Assets.

     In case of any consolidation or merger of the Company with or into any
other Person, any merger of another Person with or into the Company (other than
a merger which does not result in any reclassification, conversion, exchange or
cancellation of outstanding shares of Common Stock of the Company) or any
conveyance, sale, transfer or lease of all or substantially all of the assets of
the Company, the Person formed by such consolidation or resulting from such
merger or which acquires such assets, as the case may be, shall execute and
deliver to the Trustee a supplemental indenture providing that the Holder of
each Security of a series then Outstanding that is convertible into Common Stock
of the Company shall have the right thereafter (which right shall be the
exclusive conversion right thereafter available to said Holder), during the
period such Security shall be

                                                                            -69-

<PAGE>

convertible, to convert such Security only into the kind and amount of
securities, cash and other property receivable upon such consolidation, merger,
conveyance, sale, transfer or lease by a holder of the number of shares of
Common Stock of the Company into which such Security might have been converted
immediately prior to such consolidation, merger, conveyance, sale, transfer or
lease, assuming such holder of Common Stock of the Company (i) is not a Person
with which the Company consolidated or merged with or into or which merged into
or with the Company or to which such conveyance, sale, transfer or lease was
made, as the case may be (a "Constituent Person"), or an Affiliate of a
Constituent Person and (ii) failed to exercise his rights of election, if any,
as to the kind or amount of securities, cash and other property receivable upon
such consolidation, merger, conveyance, sale, transfer or lease (provided that
if the kind or amount of securities, cash and other property receivable upon
such consolidation, merger, conveyance, sale, transfer, or lease is not the same
for each share of Common Stock of the Company held immediately prior to such
consolidation, merger, conveyance, sale, transfer or lease by others than a
Constituent Person or an Affiliate thereof and in respect of which such rights
of election shall not have been exercised ("Non-electing Share"), then for the
purpose of this Section 14.9 the kind and amount of securities, cash and other
property receivable upon such consolidation, merger, conveyance, sale, transfer
or lease by the holders of each Non-electing Share shall be deemed to be the
kind and amount so receivable per share by a plurality of the Non-electing
Shares). Such supplemental indenture shall provide for adjustments which, for
events subsequent to the effective date of such supplemental indenture, shall be
as nearly equivalent as may be practicable to the adjustments provided for in
this Article or in accordance with the terms of the supplemental indenture or
Board Resolutions setting forth the terms of such adjustments. The above
provisions of this Section 14.9 shall similarly apply to successive
consolidations, mergers, conveyances, sales, transfers or leases. Notice of the
execution of such a supplemental indenture shall be given by the Company to the
Holder of each Security of a series that is convertible into Common Stock of the
Company as provided in Section 1.6 promptly upon such execution. Neither the
Trustee nor any conversion agent, if any, shall be under any responsibility to
determine the correctness of any provisions contained in any such supplemental
indenture relating either to the kind or amount of shares of stock or other
securities or property or cash receivable by Holders of Securities of a series
convertible into Common Stock of the Company upon the conversion of their
Securities after any such consolidation, merger, conveyance, transfer, sale or
lease or to any such adjustment, but may accept as conclusive evidence of the
correctness of any such provisions, and shall be protected in relying upon, an
Opinion of Counsel with respect thereto, which the Company shall cause to be
furnished to the Trustee upon request.

Section 14.10  Duties of Trustee Regarding Conversion.

     Neither the Trustee nor any conversion agent shall at any time be under any
duty or responsibility to any Holder of Securities of any series that is
convertible into Common Stock of the Company to determine whether any facts
exist which may require any adjustment of the conversion price, or with respect
to the nature or extent of any such adjustment when made, or with respect to the
method employed, whether herein or in any supplemental indenture, any
resolutions of the Board of Directors or written instrument executed by one or
more officers of the Company provided to be employed in making the same. Neither
the Trustee nor any conversion agent shall be accountable

                                                                            -70-

<PAGE>

with respect to the validity or value (or the kind or amount) of any shares of
Common Stock of the Company, or of any securities or property, which may at any
time be issued or delivered upon the conversion of any Securities and neither
the Trustee nor any conversion agent makes any representation with respect
thereto. Subject to the provisions of Section 6.1, neither the Trustee nor any
conversion agent shall be responsible for any failure of the Company to issue,
transfer or deliver any shares of its Common Stock or stock certificates or
other securities or property upon the surrender of any Security for the purpose
of conversion or to comply with any of the covenants of the Company contained in
this Article 14 or in the applicable supplemental indenture, resolutions of the
Board of Directors or written instrument executed by one or more duly authorized
officers of the Company.

Section 14.11  Repayment of Certain Funds upon Conversion.

     Any funds which at any time shall have been deposited by the Company or on
its behalf with the Trustee or any other paying agent for the purpose of paying
the principal of, and premium, if any, and interest, if any, on any of the
Securities (including, but not limited to, funds deposited for the sinking fund
referred to in Article 12 hereof and funds deposited pursuant to Article 13
hereof) and which shall not be required for such purposes because of the
conversion of such Securities as provided in this Article 14 shall after such
conversion be repaid to the Company by the Trustee upon the Company's written
request.

            [The remainder of this page is intentionally left blank]

                                                                            -71-

<PAGE>

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

                                   NPS Pharmaceuticals, Inc.

                                   By:__________________________________________

                                   Title:_______________________________________

                                   U.S. Bank National Association,
                                   as Trustee

                                    By:_________________________________________

                                    Title:______________________________________<PAGE>

                                                                     EXHIBIT 4.2

                            NPS PHARMACEUTICALS, INC.

                                       AND

                         U.S. BANK NATIONAL ASSOCIATION

                                   AS TRUSTEE

                                    INDENTURE

                          DATED AS OF __________, 200_

                          SUBORDINATED DEBT SECURITIES

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
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<S>                                                                                                 <C>
ARTICLE 1   DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION ..............................     1

     Section 1.1   Definitions....................................................................     1
     Section 1.2   Compliance Certificates and Opinions...........................................    10
     Section 1.3   Form of Documents Delivered to Trustee.........................................    11
     Section 1.4   Acts of Holders; Record Dates..................................................    11
     Section 1.5   Notices, etc, to Trustee and Company...........................................    13
     Section 1.6   Notice to Holders; Waiver......................................................    13
     Section 1.7   Conflict with Trust Indenture Act..............................................    14
     Section 1.8   Effect of Headings and Table of Contents.......................................    14
     Section 1.9   Successors and Assigns.........................................................    14
     Section 1.10  Separability Clause............................................................    14
     Section 1.11  Benefits of Indenture..........................................................    14
     Section 1.12  Governing Law..................................................................    15
     Section 1.13  Legal Holidays.................................................................    15
     Section 1.14  Indenture and Securities Solely Corporate Obligations..........................    15
     Section 1.15  Indenture May be Executed in Counterparts......................................    15

ARTICLE 2   SECURITY FORMS........................................................................    15

     Section 2.1   Forms Generally................................................................    15
     Section 2.2   Form of Face of Security.......................................................    16
     Section 2.3   Form of Reverse of Security....................................................    18
     Section 2.4   Form of Legend for Global Securities...........................................    23
     Section 2.5   Form of Trustee's Certificate of Authentication................................    23
     Section 2.6   Form of Conversion Notice......................................................    23

ARTICLE 3   THE SECURITIES........................................................................    25

     Section 3.1   Amount Unlimited; Issuable in Series...........................................    25
     Section 3.2   Denominations..................................................................    28
     Section 3.3   Execution, Authentication, Delivery and Dating.................................    28
     Section 3.4   Temporary Securities...........................................................    29
     Section 3.5   Registration; Registration of Transfer and Exchange............................    30
     Section 3.6   Mutilated, Destroyed, Lost and Stolen Securities...............................    31
     Section 3.7   Payment of Interest; Interest Rights Preserved.................................    32
     Section 3.8   Persons Deemed Owners..........................................................    33
     Section 3.9   Cancellation...................................................................    34
     Section 3.10  Computation of Interest........................................................    34
</TABLE>

<PAGE>

                               TABLE OF CONTENTS
                                  (continued)

<TABLE>
<CAPTION>
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                                                                                                    ----
<S>                                                                                                 <C>
ARTICLE 4   SATISFACTION AND DISCHARGE............................................................    34

     Section 4.1   Satisfaction and Discharge of Indenture........................................    34
     Section 4.2   Application of Trust Money.....................................................    35

ARTICLE 5   REMEDIES..............................................................................    35

     Section 5.1   Events of Default..............................................................    35
     Section 5.2   Acceleration of Maturity; Rescission and Annulment.............................    37
     Section 5.3   Collection of Indebtedness and Suits for Enforcement by Trustee................    38
     Section 5.4   Trustee May File Proofs of Claim...............................................    38
     Section 5.5   Trustee May Enforce Claims Without Possession of Securities....................    39
     Section 5.6   Application of Money Collected.................................................    39
     Section 5.7   Limitation on Suits............................................................    39
     Section 5.8   Unconditional Right of Holders to Receive Principal, Premium
                   and Interest and to Convert....................................................    40
     Section 5.9   Restoration of Rights and Remedies.............................................    40
     Section 5.10  Rights and Remedies Cumulative.................................................    40
     Section 5.11  Delay or Omission Not Waiver...................................................    41
     Section 5.12  Control by Holders.............................................................    41
     Section 5.13  Waiver of Past Defaults........................................................    41
     Section 5.14  Undertaking for Costs..........................................................    42
     Section 5.15  Waiver of Usury, Stay or Extension Laws........................................    42

ARTICLE 6   THE TRUSTEE...........................................................................    42

     Section 6.1   Certain Duties and Responsibilities............................................    42
     Section 6.2   Notice of Defaults.............................................................    42
     Section 6.3   Certain Rights of Trustee......................................................    43
     Section 6.4   Not Responsible for Recitals or Issuance of Securities.........................    44
     Section 6.5   May Hold Securities and Act as Trustee under Other Indentures..................    44
     Section 6.6   Money Held in Trust............................................................    45
     Section 6.7   Compensation and Reimbursement.................................................    45
     Section 6.8   Conflicting Interests..........................................................    45
     Section 6.9   Corporate Trustee Required; Eligibility........................................    45
     Section 6.10  Resignation and Removal; Appointment of Successor..............................    46
     Section 6.11  Acceptance of Appointment by Successor.........................................    47
     Section 6.12  Merger, Conversion, Consolidation or Succession to Business....................    48
     Section 6.13  Preferential Collection of Claims Against Company..............................    48
     Section 6.14  Appointment of Authenticating Agent............................................    49

ARTICLE 7   HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY.....................................    50

     Section 7.1   Company to Furnish Trustee Names and Addresses of Holders......................    50
</TABLE>

                                       ii

<PAGE>

                               TABLE OF CONTENTS
                                  (continued)

<TABLE>
<CAPTION>
                                                                                                    Page
                                                                                                    ----
<S>                                                                                                 <C>
     Section 7.2   Preservation of Information; Communications to Holders.........................    50
     Section 7.3   Reports by Trustee.............................................................    51
     Section 7.4   Reports by Company.............................................................    51

ARTICLE 8   CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE..................................    51

     Section 8.1   Company May Consolidate, etc. Only on Certain Terms............................    51
     Section 8.2   Successor Substituted..........................................................    52

ARTICLE 9   SUPPLEMENTAL INDENTURES...............................................................    53

     Section 9.1   Supplemental Indentures Without Consent of Holders.............................    53
     Section 9.2   Supplemental Indentures with Consent of Holders................................    54
     Section 9.3   Execution of Supplemental Indentures...........................................    55
     Section 9.4   Effect of Supplemental Indentures..............................................    55
     Section 9.5   Conformity with Trust Indenture Act............................................    56
     Section 9.6   Reference in Securities to Supplemental Indentures.............................    56
     Section 9.7   Subordination Unimpaired.......................................................    56

ARTICLE 10  COVENANTS.............................................................................    56

     Section 10.1  Payment of Principal, Premium and Interest.....................................    56
     Section 10.2  Maintenance of Office or Agency................................................    56
     Section 10.3  Money for Securities Payments to be Held in Trust..............................    57
     Section 10.4  Statement by Officers as to Default............................................    58
     Section 10.5  Existence......................................................................    58
     Section 10.6  Maintenance of Properties......................................................    58
     Section 10.7  Payment of Taxes and Other Claims..............................................    58
     Section 10.8  Waiver of Certain Covenants....................................................    59

ARTICLE 11  REDEMPTION OF SECURITIES..............................................................    59

     Section 11.1  Applicability of Article.......................................................    59
     Section 11.2  Election to Redeem; Notice to Trustee..........................................    59
     Section 11.3  Selection by Trustee of Securities to Be Redeemed..............................    59
     Section 11.4  Notice of Redemption...........................................................    60
     Section 11.5  Deposit of Redemption Price....................................................    61
     Section 11.6  Securities Payable on Redemption Date..........................................    61
     Section 11.7  Securities Redeemed in Part....................................................    62

ARTICLE 12  SINKING FUNDS.........................................................................    62

     Section 12.1  Applicability of Article.......................................................    62
     Section 12.2  Satisfaction of Sinking Fund Payments with Securities..........................    62
     Section 12.3  Redemption of Securities for Sinking Fund......................................    63
</TABLE>

                                      iii

<PAGE>

                               TABLE OF CONTENTS
                                  (continued)

<TABLE>
<CAPTION>
                                                                                                    Page
                                                                                                    ----
<S>                                                                                                 <C>
ARTICLE 13  DEFEASANCE AND COVENANT DEFEASANCE....................................................    63

     Section 13.1  Company's Option to Effect Defeasance or Covenant Defeasance...................    63
     Section 13.2  Defeasance and Discharge.......................................................    63
     Section 13.3  Covenant Defeasance............................................................    64
     Section 13.4  Conditions to Defeasance or Covenant Defeasance................................    65
     Section 13.5  Deposited Money, U.S. Government Obligations and Foreign Government
                   Obligations to be held in Trust, Miscellaneous Provisions......................    67
     Section 13.6  Reinstatement..................................................................    68

ARTICLE 14  CONVERSION OF SECURITIES..............................................................    68

     Section 14.1  Applicability of Article.......................................................    68
     Section 14.2  Exercise of Conversion Privilege...............................................    68
     Section 14.3  No Fractional Shares...........................................................    70
     Section 14.4  Adjustment of Conversion Price.................................................    70
     Section 14.5  Notice of Certain Corporate Actions............................................    71
     Section 14.6  Reservation of Shares of Common Stock..........................................    71
     Section 14.7  Payment of Certain Taxes upon Conversion.......................................    72
     Section 14.8  Nonassessability...............................................................    72
     Section 14.9  Provision in Case of Consolidation, Merger or Sale of Assets...................    72
     Section 14.10 Duties of Trustee Regarding Conversion.........................................    73
     Section 14.11 Repayment of Certain Funds upon Conversion.....................................    73

ARTICLE 15 SUBORDINATION OF SECURITIES............................................................    74

     Section 15.1  Agreement of Subordination.....................................................    74
     Section 15.2  Payments to Holders............................................................    74
     Section 15.3  Subrogation of Securities......................................................    77
     Section 15.4  Authorization to Effect Subordination..........................................    78
     Section 15.5  Notice to Trustee..............................................................    78
     Section 15.6  Trustee's Relation to Senior Debt..............................................    79
     Section 15.7  No Impairment of Subordination.................................................    79
     Section 15.8  Certain Conversions/Exchange Deemed Payment....................................    79
     Section 15.9  Article Applicable to Paying Agents............................................    80
     Section 15.10 Senior Debt Entitled to Rely...................................................    80
     Section 15.11 Reliance on Judicial Order or Certificate of Liquidating Agent.................    80
     Section  5.12 Trust Monies not Subordinated
</TABLE>

                                       iv

<PAGE>

                            NPS Pharmaceuticals, Inc.

     Certain Sections of this Indenture relating to Sections 310 through 318,
inclusive, of the Trust Indenture Act of 1939:

<TABLE>
<S>                                                              <C>
Section 310       (a)(1).......................................             6.9
                  (a)(2).......................................             6.9
                  (a)(3).......................................  Not Applicable
                  (a)(4).......................................  Not Applicable
                  (b)..........................................       6.8, 6.10
Section 311       (a)..........................................            6.13
                  (b)..........................................            6.13
Section 312       (a)..........................................        7.1, 7.2
                  (b)..........................................             7.2
                  (c)..........................................             7.2
Section 313       (a)..........................................             7.3
                  (b)..........................................             7.3
                  (c)..........................................             7.3
                  (d)..........................................             7.3
Section 314       (a)..........................................             7.4
                  (a)(4).......................................       1.1, 10.4
                  (b)..........................................  Not Applicable
                  (c)(1).......................................             1.2
                  (c)(2).......................................             1.2
                  (c)(3).......................................  Not Applicable
                  (d)..........................................  Not Applicable
                  (e)..........................................             1.2
Section 315       (a)..........................................             6.1
                  (b)..........................................             6.2
                  (c)..........................................             6.1
                  (d)..........................................             6.1
                  (e)..........................................            5.14
Section 316       (a)..........................................             1.1
                  (a)(1)(A)....................................       5.2, 5.12
                  (a)(1)(B)....................................            5.13
                  (a)(2).......................................  Not Applicable
                  (a)(2).......................................  Not Applicable
                  (b)..........................................             5.8
                  (c)..........................................             1.4
Section 317       (a)(1).......................................             5.3
                  (a)(2).......................................             5.4
                  (b)..........................................            10.3
Section 318       (a)..........................................             1.7
</TABLE>

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

<PAGE>

     INDENTURE, dated as of __________, 2002, between NPS Pharmaceuticals, Inc.,
a corporation duly organized and existing under the laws of the State of
Delaware (herein called the "Company"), having its principal executive office at
420 Chipeta Way, Salt Lake City, Utah 84108, and U.S. Bank National Association,
a national banking association, as Trustee (herein called the "Trustee").

                             RECITALS OF THE COMPANY

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

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

                   NOW, THEREFORE, THIS INDENTURE WITNESSETH:

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

                                    ARTICLE 1

             DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

Section 1.1 Definitions.

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

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

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

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

            (4)    all references to "$" refer to the lawful currency of the
    United States of America;

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

<PAGE>

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

     "Act," when used with respect to any Holder, has the meaning specified in
Section 1.4.

     "Affiliate" of any specified Person means any other Person directly or
indirectly controlling or controlled by or under direct or indirect common
control with such specified Person.

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

     "Board of Directors" means either the board of directors of the Company or
any duly authorized committee of that board empowered to act for it with respect
to this Indenture.

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

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

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

     "Common Stock" includes any stock of any class of the Company which has no
preference in respect of dividends or of amounts payable in the event of any
voluntary or involuntary liquidation, dissolution or winding-up of the Company
and which is not subject to redemption by the Company; provided, however,
                                                       --------  -------
subject to the provisions of Section 14.9, shares issuable upon conversion of
Securities shall include only shares of the class designated as Common Stock of
the Company at the date of this Indenture or shares of any class or classes
resulting from any reclassification or reclassifications thereof and which have
no preference in respect of dividends or of amounts payable in the event of any
voluntary or involuntary liquidation, dissolution or winding-up of the Company
and which are not subject to redemption by the Company; provided, further, that
                                                        --------  -------
if at any time there shall be more than one such resulting class, the shares of
each such class then so issuable shall be substantially in the proportion which
the total number of shares of such class resulting from all such
reclassifications bears to the total number of shares of all such classes
resulting from all such reclassifications.

                                                                             -2-

<PAGE>

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

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

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

     "Corporate Trust Office" means the corporate trust office of the Trustee at
180 East Fifth Street, St. Paul, Minnesota 55101, Attention: Corporate Trust
Department, or such other office, designated by the Trustee by written notice to
the Company, at which at any particular time its corporate trust business shall
be administered.

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

     "Covenant Defeasance" has the meaning specified in Section 13.3.

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

     "Defeasance" has the meaning specified in Section 13.2.

     "Depositary" means, with respect to Securities of any series issuable in
whole or in part in the form of one or more Global Securities, a clearing agency
registered under the Exchange Act that is designated to act as Depositary for
such Securities as contemplated by Section 3.1.

     "Designated Senior Debt" means the Company's obligations under any
particular Senior Debt in which the instrument creating or evidencing the same
or the assumption or guarantee thereof (or related agreements or documents to
which the Company is a party) expressly provides that such Senior Debt shall be
"Designated Senior Debt" for purposes of this Indenture (provided that such
instrument, agreement or other document may place limitations and conditions on
the right of such Senior Debt to exercise the rights of Designated Senior Debt).
If any payment made to any holder of any Designated Senior Debt or its
Representative with respect to such Designated Senior Debt is rescinded or must
otherwise be returned by such holder or Representative upon the insolvency,
bankruptcy or reorganization of the Company or otherwise, the reinstated
Indebtedness of the Company arising as a result of such rescission or return
shall constitute Designated Senior Debt effective as of the date of such
rescission or return.

                                                                             -3-

<PAGE>

     "euro" or "euros" means the currency adopted by those nations participating
in the third stage of the economic and monetary union provisions of the Treaty
on European Union, signed at Maastricht on February 7, 1992.

     "European Economic Area" means the member nations of the European Economic
Area pursuant to the Oporto Agreement on the European Economic Area dated May 2,
1992, as amended.

     "European Union" means the member nations of the European Union established
by the Treaty of European Union, signed at Maastricht on February 2, 1992, which
amended the Treaty of Rome establishing the European Community.

     "Event of Default" has the meaning specified in Section 5.1.

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

     "Expiration Date" has the meaning specified in Section 1.4.

     "Foreign Government Obligation" means with respect to Securities of any
series which are not denominated in the currency of the United States of America
(x) any security which is (i) a direct obligation of the government which issued
or caused to be issued the currency in which such Security is denominated and
for the payment of which obligations its full faith and credit is pledged or,
with respect to Securities of any series which are denominated in euros, a
direct obligation of any member nation of the European Union for the payment of
which obligation the full faith and credit of the respective nation is pledged
so long as such nation has a credit rating at least equal to that of the highest
rated member nation of the European Economic Area, or (ii) an obligation of a
Person controlled or supervised by and acting as an agency or instrumentality of
a government specified in Clause (i) above the payment of which is
unconditionally guaranteed as a full faith and credit obligation by the such
government, which, in either case (i) or (ii), is not callable or redeemable at
the option of the issuer thereof, and (y) any depositary receipt issued by a
bank (as defined in Section 3(a)(2) of the Securities Act) as custodian with
respect to any Foreign Government Obligation which is specified in Clause (x)
above and held by such bank for the account of the holder of such depositary
receipt, or with respect to any specific payment of principal of or interest on
any Foreign Government Obligation which is so specified and held, provided that
(except as required by law) such custodian is not authorized to make any
deduction from the amount payable to the holder of such depositary receipt from
any amount received by the custodian in respect of the Foreign Government
Obligation or the specific payment of principal or interest evidenced by such
depositary receipt.

     "Global Security" means a Security that evidences all or part of the
Securities of any series and bears the legend set forth in Section 2.4 (or such
legend as may be specified as contemplated by Section 3.1 for such Securities).

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

                                                                             -4-

<PAGE>

     "Indebtedness" means, with respect to any Person, and without duplication,
(a) all indebtedness, obligations and other liabilities (contingent or
otherwise) of such Person for borrowed money (including obligations of such
Person in respect of overdrafts, foreign exchange contracts, currency exchange
agreements, interest rate protection agreements, and any loans or advances from
banks, whether or not evidenced by notes or similar instruments) or evidenced by
bonds, debentures, notes or similar instruments (whether or not the recourse of
the lender is to the whole of the assets of such person or to only a portion
thereof), other than any account payable or other accrued current liability or
obligation incurred in the ordinary course of business in connection with the
obtaining of materials or services; (b) all reimbursement obligations and other
liabilities (contingent or otherwise) of such Person with respect to letters of
credit, bank guarantees or bankers' acceptances; (c) all obligations and
liabilities (contingent or otherwise) in respect of leases of such Person
required, in conformity with generally accepted accounting principles, to be
accounted for as capitalized lease obligations on the balance sheet of such
Person and all obligations and other liabilities (contingent or otherwise) under
any lease or related document (including a purchase agreement) in connection
with the lease of real property which provides that such Person is contractually
obligated to purchase or cause a third party to purchase the leased property and
thereby guarantee a minimum residual value of the leased property to the lessor
and the obligations of such Person under such lease or related document to
purchase or to cause a third party to purchase such leased property; (d) all
obligations of such Person (contingent or otherwise) with respect to an interest
rate or other swap, cap or collar agreement or other similar instrument or
agreement or foreign currency hedge, exchange, purchase or similar instrument or
agreement; (e) all direct or indirect guaranties or similar agreements by such
Person in respect of, and obligations or liabilities (contingent or otherwise)
of such Person to purchase or otherwise acquire or otherwise assure a creditor
against loss in respect of, indebtedness, obligations or liabilities of another
person of the kind described in clauses (a) through (d) above; (f) any
indebtedness or other obligations described in clauses (a) through (e) above
secured by any mortgage, pledge, lien or other encumbrance existing on property
which is owned or held by such Person, regardless of whether the indebtedness or
other obligation secured thereby shall have been assumed by such Person; and (g)
any and all deferrals, renewals, extensions and refundings of, or amendments,
modifications or supplements to, any indebtedness, obligation or liability of
the kind described in clauses (a) through (f) above.

     "Indenture" means this instrument as originally executed and as it may from
time to time be supplemented or amended by one or more indentures supplemental
hereto entered into pursuant to the applicable provisions hereof, including, for
all purposes of this instrument and any such supplemental indenture, the
provisions of the Trust Indenture Act that are deemed to be a part of and govern
this instrument and any such supplemental indenture, respectively. The term
"Indenture" shall also include the terms of particular series of Securities
established as contemplated by Section 3.1; provided, however, that if at any
                                            --------  -------
time more than one Person is acting as Trustee under this Indenture due to the
appointment of one or more separate Trustees for any one or more separate series
of Securities, "Indenture" shall mean, with respect to such series of Securities
for which any such Person is Trustee, 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 pursuant to the applicable provisions hereof
and shall include the terms of particular series of Securities for which such
Person is Trustee established as contemplated by Section 3.1, exclusive,
however, of any

                                                                             -5-

<PAGE>

provisions or terms which relate solely to other series of Securities for which
such Person is not Trustee, regardless of when such terms or provisions were
adopted, and exclusive of any provisions or terms adopted by means of one or
more indentures supplemental hereto executed and delivered after such Person had
become such Trustee, but to which such person, as such Trustee, was not a party;
provided, further that in the event that this Indenture is supplemented or
--------  -------
amended by one or more indentures supplemental hereto which are only applicable
to certain series of Securities, the term "Indenture" for a particular series of
Securities shall only include the supplemental indentures applicable thereto.

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

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

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

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

     "Notice of Default" means a written notice of the kind specified in Section
5.1(4).

     "Officers' Certificate" means a certificate signed by the Chairman of the
Board, a Vice Chairman of the Board, the Chief Executive Officer, the President
or a Vice President, and by the principal financial officer, the Treasurer, an
Assistant Treasurer, the Secretary or an Assistant Secretary, of the Company,
and delivered to the Trustee. One of the officers signing an Officers'
Certificate given pursuant to Section 10.4 shall be the principal executive,
financial or accounting officer of the Company.

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

     "Original Issue Discount Security" means any Security that provides for an
amount less than the principal amount thereof to be due and payable upon a
declaration of acceleration of the Maturity thereof pursuant to Section 5.2.

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

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

                                                                             -6-

<PAGE>

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

            (3)    Securities as to which Defeasance has been effected pursuant
     to Section 13.2; and

            (4)    Securities which have been paid pursuant to Section 3.6 or in
     exchange for or in lieu of which other Securities have been authenticated
     and delivered pursuant to this Indenture, other than any such Securities in
     respect of which there shall have been presented to the Trustee proof
     satisfactory to it that such Securities are held by a bona fide
     purchaser in whose hands such Securities are valid obligations of the
     Company;

provided, however, that in determining whether the Holders of the requisite
--------  -------
principal amount of the Outstanding Securities have given, made or taken any
request, demand, authorization, direction, notice, consent, waiver or other
action hereunder as of any date, (A) the principal amount of an Original Issue
Discount Security which shall be deemed to be Outstanding shall be the amount of
the principal thereof which would be due and payable as of such date upon
acceleration of the Maturity thereof to such date pursuant to Section 5.2, (B)
if, as of such date, the principal amount payable at the Stated Maturity of a
Security is not determinable, the principal amount of such Security which shall
be deemed to be Outstanding shall be the amount as specified or determined as
contemplated by Section 3.1, (C) the principal amount of a Security denominated
in one or more non-U.S dollar currencies or currency units which shall be deemed
to be Outstanding shall be the U.S. dollar equivalent, determined as of such
date in the manner provided as contemplated by Section 3.1, of the principal
amount of such Security (or, in the case of a Security described in Clause (A)
or (B) above, of the amount determined as provided in such Clause), and (D)
Securities owned by the Company or any other obligor upon the Securities or any
Affiliate of the Company or of such other obligor shall be disregarded and
deemed not to be Outstanding, except that, in determining whether the Trustee
shall be protected in relying upon any such request, demand, authorization,
direction, notice, consent, waiver or other action, only Securities which the
Trustee knows to be so owned shall be so disregarded. Securities so owned which
have been pledged in good faith may be regarded as Outstanding if the pledgee
establishes to the satisfaction of the Trustee the pledgee's right so to act
with respect to such Securities and that the pledgee is not the Company or any
other obligor upon the Securities or any Affiliate of the Company or of such
other obligor.

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

     "Payment Blockage Notice" has the meaning specified in Section 15.2.

                                                                             -7-

<PAGE>

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

     "Place of Payment," when used with respect to the Securities of any series,
means the place or places where the principal of and any premium and interest on
the Securities of that series are payable as specified as contemplated by
Section 3.1.

     "Predecessor Security" of any particular Security means every previous
Security evidencing all or a portion of the same debt as that evidenced by such
particular Security; and, for the purposes of this definition, any Security
authenticated and delivered under Section 3.6 in exchange for or in lieu of a
mutilated, destroyed, lost or stolen Security shall be deemed to evidence the
same debt as the mutilated, destroyed, lost or stolen Security.

     "Record Date" means any Regular Record Date or Special Record Date.

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

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

     "Regular Record Date" for the interest payable on any Interest Payment Date
on the Securities of any series means the date specified for that purpose as
contemplated by Section 3.1.

     "Representative" means the (a) indenture trustee or other trustee, agent or
representative for any Senior Debt or (b) with respect to any Senior Debt that
does not have any such trustee, agent or other representative, (i) in the case
of such Senior Debt issued pursuant to an agreement providing for voting
arrangements as among the holders or owners of such Senior Debt, any holder or
owner of such Senior Debt acting with the consent of the required persons
necessary to bind such holders or owners of such Senior Debt and (ii) in the
case of all other such Senior Debt, the holder or owner of such Senior Debt.

     "Responsible Officer" means, when used with respect to the Trustee, an
officer of the Trustee in the Corporate Trust Office assigned and duly
authorized by the Trustee to administer its corporate trust matters.

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

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

     "Security Register" and "Security Registrar" have the respective meanings
specified in Section 3.5.
                                                                             -8-

<PAGE>

     "Senior Debt" means the principal of, premium, if any, interest (including
all interest accruing subsequent to the commencement of any bankruptcy or
similar proceeding, whether or not a claim for post-petition interest is
allowable as a claim in any such proceeding) and rent payable on or in
connection with, and all fees, costs, expenses and other amounts accrued or due
on or in connection with, Indebtedness of the Company, whether outstanding on
the date of this Indenture or thereafter created, incurred, assumed, guaranteed
or in effect guaranteed by the Company (including all deferrals, renewals,
extensions or refundings of, or amendments, modifications or supplements to, the
foregoing), unless in the case of any particular Indebtedness the instrument
creating or evidencing the same or the assumption or guarantee thereof expressly
provides that such Indebtedness shall not be senior in right of payment to the
Securities or expressly provides that such Indebtedness is "pari passu" or "
junior" to the Securities. Notwithstanding the foregoing, the term Senior Debt
shall not include any Indebtedness of the Company to any subsidiary of the
Company. If any payment made to any holder of any Senior Indebtedness or its
Representative with respect to such Senior Debt is rescinded or must otherwise
be returned by such holder or Representative upon the insolvency, bankruptcy or
reorganization of the Company or otherwise, the reinstated Indebtedness of the
Company arising as a result of such rescission or return shall constitute Senior
Debt effective as of the date of such rescission or return.

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

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

     "Subsidiary" means a Person of which at least a majority of the outstanding
voting stock having the power to elect a majority of the board of directors of
such Person (in the case of a corporation) is, or of which at least a majority
of the equity interests (in the case of a Person which is not a corporation)
are, at the time owned, directly or indirectly, by the Company or by one or more
other Subsidiaries, or by the Company and one or more other Subsidiaries. For
the purposes of this definition, "voting stock" means stock which ordinarily has
voting power for the election of directors, whether at all times or only so long
as no senior class of stock has such voting power by reason of any contingency.

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

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

                                                                             -9-

<PAGE>

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

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

Section 1.2 Compliance Certificates and Opinions.

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

     Every certificate or opinion with respect to compliance with a condition or
covenant provided for in this Indenture shall include,

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

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

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

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

                                                                            -10-

<PAGE>

Section 1.3 Form of Documents Delivered to Trustee.

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

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

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

Section 1.4 Acts of Holders; Record Dates.

     Any request, demand, authorization, direction, notice, consent, waiver or
other action provided or permitted by this Indenture to be given, made or taken
by Holders may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Holders in person or by agent duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required, to the Company. The
Trustee shall promptly deliver to the Company copies of all such instrument or
instruments delivered to the Trustee. Such instrument or instruments (and the
action embodied therein and evidenced thereby) are herein sometimes referred to
as the "Act" of the Holders signing such instrument or instruments. Proof of
execution of any such instrument or of a writing appointing any such agent shall
be sufficient for any purpose of this Indenture and (subject to Section 6.1)
conclusive in favor of the Trustee and the Company, if made in the manner
provided in this Section.

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

                                                                            -11-

<PAGE>

execution of any such instrument or writing, or the authority of the Person
executing the same, may also be proved in any other manner that the Trustee
deems sufficient.

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

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

     The Company may set any day as a record date for the purpose of determining
the Holders of Outstanding Securities of any series entitled to give, make or
take any request, demand, authorization, direction, vote, notice, consent,
waiver or other action provided or permitted by this Indenture to be given, made
or taken by Holders of Securities of such series, provided that the Company may
                                                  --------
not set a record date for, and the provisions of this paragraph shall not apply
with respect to, the giving or making of any notice, declaration, request or
direction referred to in the next paragraph. If any record date is set pursuant
to this paragraph, the Holders of Outstanding Securities of the relevant series
on such record date, and no other Holders, shall be entitled to take the
relevant action, whether or not such Holders remain Holders after such record
date; provided that no such action shall be effective hereunder unless taken on
      --------
or prior to the applicable Expiration Date by Holders of the requisite principal
amount of Outstanding Securities of such series on such record date. Nothing in
this paragraph shall be construed to prevent the Company from setting a new
record date for any action for which a record date has previously been set
pursuant to this paragraph (whereupon the record date previously set shall
automatically and with no action by any Person be canceled and of no effect),
and nothing in this paragraph shall be construed to render ineffective any
action taken by Holders of the requisite principal amount of Outstanding
Securities of the relevant series on the date such action is taken. Promptly
after any record date is set pursuant to this paragraph, the Company, at its own
expense, shall cause notice of such record date, the proposed action by Holders
and the applicable Expiration Date to be given to the Trustee in writing and to
each Holder of Securities of the relevant series in the manner set forth in
Section 1.6.

     The Trustee may set any day as a record date for the purpose of determining
the Holders of Outstanding Securities of any series entitled to join in the
giving or making of (i) any Notice of Default, (ii) any declaration of
acceleration referred to in Section 5.2, (iii) any request to institute
proceedings referred to in Section 5.7(2) or (iv) any direction referred to in
Section 5.12, in each case with respect to Securities of such series. If any
record date is set pursuant to this paragraph, the Holders of Outstanding
Securities of such series on such record date, and no other Holders, shall be
entitled to join in such notice, declaration, request or direction, whether or
not such Holders remain Holders after such record date; provided that no such
                                                        --------
action shall be effective hereunder unless taken on or prior to the applicable
Expiration Date by Holders of the requisite principal amount of Outstanding
Securities of such series on such record date. Nothing in this paragraph shall
be construed to prevent the Trustee from setting a new record date for any
action for which a record date has previously been set pursuant to this
paragraph (whereupon the record date previously set

                                                                            -12-

<PAGE>

shall automatically and with no action by any Person be canceled and of no
effect), and nothing in this paragraph shall be construed to render ineffective
any action taken by Holders of the requisite principal amount of Outstanding
Securities of the relevant series on the date such action is taken. Promptly
after any record date is set pursuant to this paragraph, the Trustee, at the
Company's expense, shall cause notice of such record date, the proposed action
by Holders and the applicable Expiration Date to be given to the Company in
writing and to each Holder of Securities of the relevant series in the manner
set forth in Section 1.6.

     With respect to any record date set pursuant to this Section, the party
hereto which sets such record dates may designate any day as the "Expiration
Date" and from time to time may change the Expiration Date to any earlier or
later day; provided that no such change shall be effective unless notice of the
           --------
proposed new Expiration Date is given to the other party hereto in writing, and
to each Holder of Securities of the relevant series in the manner set forth in
Section 1.6, on or prior to the existing Expiration Date. If an Expiration Date
is not designated with respect to any record date set pursuant to this Section,
the party hereto which set such record date shall be deemed to have initially
designated the 180th day after such record date as the Expiration Date with
respect thereto, subject to its right to change the Expiration Date as provided
in this paragraph. Notwithstanding the foregoing, no Expiration Date shall be
later than the 180th day after the applicable record date.

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

Section 1.5 Notices, etc. to Trustee and Company.

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

            (1)    the Trustee by any Holder or by the Company shall be
     sufficient for every purpose hereunder if made, given, furnished or filed
     in writing (or by facsimile transmissions, provided that oral confirmation
     of receipt shall have been received) to or with the Trustee at its
     Corporate Trust Office, Attention: Corporate Trust Department, or

            (2)    the Company by the Trustee or by any Holder shall be
     sufficient for every purpose hereunder (unless otherwise herein expressly
     provided) if in writing and mailed, first-class postage prepaid, personally
     delivered or sent via overnight courier to the Company addressed to it at
     the address of its principal office specified in the first paragraph of
     this instrument or at any other address previously furnished in writing to
     the Trustee by the Company, Attention: Chief Financial Officer.

Section 1.6 Notice to Holders; Waiver.

     Where this Indenture provides for notice to Holders of any event, such
notice shall be sufficiently given (unless otherwise herein expressly provided)
if in writing and mailed, first-class postage prepaid or delivered by hand or
overnight courier, to each Holder affected by such event, at its address as it
appears in the Security Register, not later than the latest date (if any), and
not earlier

                                                                            -13-

<PAGE>

than the earliest date (if any), prescribed for the giving of such notice.
Neither the failure to mail or deliver by hand or overnight courier any notice,
nor any defect in any notice so mailed or delivered by hand or overnight
courier, to any particular Holder shall affect the sufficiency of such notice
with respect to other Holders. Where this Indenture provides for notice in any
manner, such notice may be waived in writing by the Person entitled to receive
such notice, either before or after the event, and such waiver shall be the
equivalent of such notice. Waivers of notice by Holders shall be filed with the
Trustee, but such filing shall not be a condition precedent to the validity of
any action taken in reliance upon such waiver.

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

Section 1.7  Conflict with Trust Indenture Act.

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

Section 1.8  Effect of Headings and Table of Contents.

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

Section 1.9  Successors and Assigns.

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

Section 1.10 Separability Clause.

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

Section 1.11 Benefits of Indenture.

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

                                                                            -14-

<PAGE>

Section 1.12 Governing Law.

     THIS INDENTURE AND THE SECURITIES SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT GIVING EFFECT TO SUCH
STATE'S CONFLICTS OF LAWS PRINCIPLES.

Section 1.13 Legal Holidays.

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

Section 1.14 Indenture and Securities Solely Corporate Obligations.

     No recourse for the payment of the principal of or premium, if any, or
interest on any Security, or for any claim based thereon or otherwise in respect
thereof, and no recourse under or upon any obligation, covenant or agreement of
the Company in this Indenture or in any supplemental indenture or in any
Security, or because of the creation of any indebtedness represented thereby,
shall be had against any incorporator, stockholder, employee, agent, officer, or
director or subsidiary, as such, past, present or future, of the Company or of
any successor corporation, either directly or through the Company or any
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 all such liability is hereby expressly waived and
released as a condition of, and as a consideration for, the execution of this
Indenture and the issue of the Securities.

Section 1.15 Indenture May be Executed in Counterparts.

     This instrument 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.

                                    ARTICLE 2

                                 SECURITY FORMS

Section 2.1  Forms Generally.

     The Securities of each series shall be in substantially the form set forth
in this Article, or in such other form as shall be established by or pursuant to
a Board Resolution or in one or more

                                                                            -15-

<PAGE>

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

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

Section 2.2 Form of Face of Security.

     [INSERT ANY LEGEND REQUIRED BY THE INTERNAL REVENUE CODE AND THE
REGULATIONS THEREUNDER.]

                            NPS PHARMACEUTICALS, INC.

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

NO. _____                                                           $___________
                                                              CUSIP: ___________

     NPS Pharmaceuticals, Inc., a corporation duly organized and existing under
the laws of Delaware (herein called the "Company," which term includes any
successor Person under the Indenture hereinafter referred to), for value
received, hereby promises to pay to _______________________________, or
registered assigns, the principal sum of
________________________________________ dollars on ____________ [if the
Security is to bear interest prior to Maturity, insert --, and to pay interest
thereon from _________ or from the most recent Interest Payment Date to which
interest has been paid or duly provided for, semi-annually on ___________ and
__________ in each year, commencing _______________, at the rate of ____% per
annum, until the principal hereof is paid or made available for payment [if
applicable, insert -- , provided that any principal and premium, and any such
installment of interest, which is overdue shall bear interest at the rate of
___% per annum (to the extent that the payment of such interest shall be legally
enforceable), from the dates such amounts are due until they are paid or made
available for payment, and such interest shall be payable on demand]. The
interest so payable, and punctually paid or duly provided for, on any Interest
Payment Date will, as provided in such Indenture, be paid to the Person in whose
name this Security (or one or more Predecessor Securities)

                                                                            -16-

<PAGE>

is registered at the close of business on the Regular Record Date for such
interest, which shall be the ___________ or ___________ (whether or not a
Business Day), as the case may be, next preceding such Interest Payment Date.
Any such interest not so punctually paid or duly provided for will forthwith
cease to be payable to the Holder on such Regular Record Date and may either be
paid to the Person in whose name this Security (or one or more Predecessor
Securities) is registered at the close of business on a Special Record Date for
the payment of such Defaulted Interest to be fixed by the Trustee, notice
whereof shall be given to Holders of Securities of this series not less than 10
days prior to such Special Record Date, or be paid at any time in any other
lawful manner not inconsistent with the requirements of any securities exchange
on which the Securities of this series may be listed, and upon such notice as
may be required by such exchange, all as more fully provided in said Indenture].

     [If the Security is not to bear interest prior to Maturity, insert -- The
principal of this Security shall not bear interest except in the case of a
default in payment of principal upon acceleration, upon redemption or at Stated
Maturity and in such case the overdue principal and any overdue premium shall
bear interest at the rate of ___% per annum (to the extent that the payment of
such interest shall be legally enforceable), from the dates such amounts are due
until they are paid or made available for payment. Interest on any overdue
principal or premium shall be payable on demand. Any such interest on overdue
principal or premium which is not paid on demand shall bear interest at the rate
of ___% per annum (to the extent that the payment of such interest on interest
shall be legally enforceable), from the date of such demand until the amount so
demanded is paid or made available for payment. Interest on any overdue interest
shall be payable on demand.] Payment of the principal of (and premium, if any)
and [if applicable, insert -- any such] interest on this Security will be made
at the office or agency of the Company maintained for that purpose in
_____________________, in such coin or currency of the United States of America
as at the time of payment is legal tender for payment of public and private
debts [if applicable, insert -- ; provided, however, that at the option of the
                                  --------  -------
Company payment of interest may be made by check mailed to the address of the
Person entitled thereto as such address shall appear in the Security Register].

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

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

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

Dated: __________________                     NPS PHARMACEUTICALS, INC.

                                              By:_______________________________

                                              Title:____________________________

                                                                            -17-

<PAGE>

ATTEST:

________________________________

Section 2.3 Form of Reverse of Security.

     This Security is one of a duly authorized issue of securities of the
Company (herein called the "Securities"), issued and to be issued in one or more
series under an Indenture, dated as of ____________, 200_ (herein called the
"Indenture," which term shall have the meaning assigned to it in such
instrument), between the Company and U.S. Bank National Association, as Trustee
(herein called the "Trustee," which term includes any successor trustee under
the Indenture), and reference is hereby made to the Indenture and all indentures
supplemental thereto for a statement of the respective rights, limitations of
rights, duties and immunities thereunder of the Company, the Trustee, the
holders of Senior Debt and the Holders of the Securities and of the terms upon
which the Securities are, and are to be, authenticated and delivered. This
Security is one of the series designated on the face hereof [if applicable,
insert -- , limited in aggregate principal amount to $_________].

     [If applicable, insert -- The Securities of this series are subject to
redemption upon not less than [if applicable, insert -- 30] days' notice by
mail, [IF APPLICABLE, INSERT -- (1) on _____________ in any year commencing with
the year _____ and ending with the year _____ through operation of the sinking
fund for this series at a Redemption Price equal to 100% of the principal
amount, and (2)] at any time [if applicable, insert -- on or after
_____________, 20__], as a whole or in part, at the election of the Company, at
the following Redemption Prices (expressed as percentages of the principal
amount): If redeemed [if applicable, insert -- on or before ______________,
___%, and if redeemed] during the 12-month period beginning ________ of the
years indicated,

     Year            Redemption Price           Year           Redemption Price
----------------  -----------------------  ---------------   -------------------

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

     [If applicable, insert --The Securities of this series are subject to
redemption upon not less than [if applicable, insert -- 30] days' notice by
mail, (1) on _________ in any year commencing with the year _____ and ending
with the year _____ through operation of the sinking fund for this series at the
Redemption Prices for redemption through operation of the sinking fund
(expressed as percentages of the principal amount) set forth in the table below,
and (2) at any time [if applicable,

                                                                            -18-

<PAGE>

insert -- on or after __________], as a whole or in part, at the election of the
Company, at the Redemption Prices for redemption otherwise than through
operation of the sinking fund (expressed as percentages of the principal amount)
set forth in the table below: If redeemed during the 12-month period beginning
________ of the years indicated,

                  Redemption Price For          Redemption Price For Redemption
                   Redemption Through               Otherwise Than Through
   Year       Operation of the Sinking Fund      Operation of the Sinking Fund
----------   -------------------------------   ---------------------------------

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

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

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

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

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

                                                                            -19-

<PAGE>

[If the Security is convertible into Common Stock of the Company, insert --
Subject to the provisions of the Indenture, the Holder of this Security is
entitled, at its option, at any time on or before [insert date] (except that, in
case this Security or any portion hereof shall be called for redemption, such
right shall terminate with respect to this Security or portion hereof, as the
case may be, so called for redemption at the close of business on the first
Business Day next preceding the date fixed for redemption as provided in the
Indenture unless the Company defaults in making the payment due upon
redemption), to convert the principal amount of this Security (or any portion
hereof which is $1,000 or an integral multiple thereof), into fully paid and
non-assessable shares (calculated as to each conversion to the nearest 1/100th
of a share) of the Common Stock of the Company, as said shares shall be
constituted at the date of conversion, at the conversion price of $_____________
principal amount of Securities for each share of Common Stock, or at the
adjusted conversion price in effect at the date of conversion determined as
provided in the Indenture, upon surrender of this Security, together with the
conversion notice hereon duly executed, to the Company at the designated office
or agency of the Company in ____________, accompanied (if so required by the
Company) by instruments of transfer, in form satisfactory to the Company and to
the Trustee, duly executed by the Holder or by its duly authorized attorney in
writing.

     Such surrender shall, if made during any period beginning at the close of
business on a Regular Record Date and ending at the opening of business on the
Interest Payment Date next following such Regular Record Date (unless this
Security or the portion being converted shall have been called for redemption on
a Redemption Date during the period beginning at the close of business on a
Regular Record Date and ending at the opening of business on the first Business
Day after the next succeeding Interest Payment Date, or if such Interest Payment
Date is not a Business Day, the second such Business Day), also be accompanied
by payment in funds acceptable to the Company of an amount equal to the interest
payable on such Interest Payment Date on the principal amount of this Security
then being converted. Subject to the aforesaid requirement for payment and, in
the case of a conversion after the Regular Record Date next preceding any
Interest Payment Date and on or before such Interest Payment Date, to the right
of the Holder of this Security (or any Predecessor Security) of record at such
Regular Record Date to receive an installment of interest (with certain
exceptions provided in the Indenture), no adjustment is to be made on conversion
for interest accrued hereon or for dividends on shares of Common Stock issued on
conversion. The Company is not required to issue fractional shares upon any such
conversion, but shall make adjustment therefor in cash on the basis of the
current market value of such fractional interest as provided in the Indenture.
The conversion price is subject to adjustment as provided in the Indenture. In
addition, the Indenture provides that in case of certain consolidations or
mergers to which the Company is a party or the sale of substantially all of the
assets of the Company, the Indenture shall be amended, without the consent of
any Holders of Securities, so that this Security, if then outstanding, will be
convertible thereafter, during the period this Security shall be convertible as
specified above, only into the kind and amount of securities, cash and other
property receivable upon the consolidation, merger or sale by a holder of the
number of shares of Common Stock into which this Security might have been
converted immediately prior to such consolidation, merger or sale (assuming such
holder of Common Stock failed to exercise any rights of election and received
per share the kind and amount received per share by a plurality of non-electing
shares). In the event

                                                                            -20-

<PAGE>

of conversion of this Security in part only, a new Security or Securities for
the unconverted portion hereof shall be issued in the name of the Holder hereof
upon the cancellation hereof.]

     [If the Security is convertible into other securities of the Company,
specify the conversion features.]

     The indebtedness evidenced by this Security is, to the extent and in the
manner provided in the Indenture, subordinate and subject in right of payment to
the prior payment in full of all Senior Debt of the Company, and this Security
is issued subject to such provisions of the Indenture with respect thereto. Each
Holder of this Security, by accepting the same, (a) agrees to and shall be bound
by such provisions, (b) authorizes and directs the Trustee on his behalf to take
such action as may be necessary or appropriate to effectuate the subordination
so provided and (c) appoints the Trustee his attorney-in-fact for any and all
such purposes.

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

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

     The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of more than 50% in principal amount of the Securities at
the time Outstanding of each series to be affected. The Indenture also contains
provisions permitting the Holders of specified percentages in principal amount
of the Securities of each series at the time Outstanding, on behalf of the
Holders of all Securities of such series, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the
Indenture and their consequences. Any such consent or waiver by the Holder of
this Security shall be conclusive and binding upon such Holder and upon all
future Holders of this Security and of any Security issued upon the registration
of transfer hereof or in exchange herefor or in lieu hereof, whether or not
notation of such consent or waiver is made upon this Security.

     As provided in and subject to the provisions of the Indenture, the Holder
of this Security shall not have the right to institute any proceeding with
respect to the Indenture or for the appointment of a receiver or trustee or for
any other remedy thereunder, unless such Holder shall have previously given the
Trustee written notice of a continuing Event of Default with respect to the

                                                                            -21-

<PAGE>

Securities of this series, the Holders of not less than a majority in principal
amount of the Securities of this series at the time Outstanding shall have made
written request to the Trustee to institute proceedings in respect of such Event
of Default as Trustee and offered the Trustee reasonable indemnity, and the
Trustee shall not have received from the Holders of a majority in principal
amount of Securities of this series at the time Outstanding a direction
inconsistent with such request, and shall have failed to institute any such
proceeding, for 60 days after receipt of such notice, request and offer of
indemnity. The foregoing shall not apply to any suit instituted by the Holder of
this Security for the enforcement of any payment of principal hereof or any
premium or interest hereon on or after the respective due dates expressed
herein.

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

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

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

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

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

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

                                                                            -22-

<PAGE>

Section 2.4  Form of Legend for Global Securities.

     Unless otherwise specified as contemplated by Section 3.1 for the
Securities evidenced thereby, every Global Security authenticated and delivered
hereunder shall bear a legend in substantially the following form:

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

Section 2.5  Form of Trustee's Certificate of Authentication.

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

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

                                              U.S. Bank National Association,
                                              as Trustee

                                              By: ______________________________
                                                  Authorized Officer

Section 2.6  Form of Conversion Notice.

Conversion notices shall be in substantially the following form:

To NPS Pharmaceuticals, Inc.:

     The undersigned owner of this Security hereby irrevocably exercises the
option to convert this Security, or portion hereof (which is $1,000 or an
integral multiple thereof) below designated, into shares of Common Stock of the
Company in accordance with the terms of the Indenture referred to in this
Security, and directs that the shares issuable and deliverable upon the
conversion, together with any check in payment for fractional shares and any
Securities representing any unconverted principal amount hereof, be issued and
delivered to the registered holder hereof unless a different name has been
indicated below. If this Notice is being delivered on a date after the close of
business on a Regular Record Date and prior to the opening of business on the
related Interest Payment Date (unless this Security or the portion thereof being
converted has been called for redemption on a Redemption Date during the period
beginning at the close of business on a Regular Record Date and

                                                                            -23-

<PAGE>

ending at the opening of business on the first Business Day after the next
succeeding Interest Payment Date, or if such Interest Payment Date is not a
Business Day, the second such Business Day), this Notice is accompanied by
payment, in funds acceptable to the Company, of an amount equal to the interest
payable on such Interest Payment Date of the principal of this Security to be
converted. If shares are to be issued in the name of a person other than the
undersigned, the undersigned will pay all transfer taxes payable with respect
hereto. Any amount required to be paid by the undersigned on account of interest
accompanies this Security.

         Principal Amount to be Converted
(in an integral multiple of $1,000, if less than all):
         U.S. $_____________.

Dated: _____________________

                                             Signature(s) must be guaranteed by
                                             an eligible guarantor institution
                                             (banks, stockbrokers, savings and
                                             loan associations and credit unions
                                             with membership in an approved
                                             signature guarantee medallion
                                             program) pursuant to Securities and
                                             Exchange Commission Rule 17Ad-15.

                                             ___________________________________
                                             Signature Guaranty

     Fill in for registration of shares of Common Stock and Security if to be
issued otherwise than to the registered Holder.

_____________________________________        ___________________________________
(Name)                                       Social Security or Other Taxpayer
                                             Identification Number

_____________________________________
Please print Name and Address
(including zip code)

[The above conversion notice is to be modified, as appropriate, for conversion
into other securities or property of the Company.]

                                                                            -24-

<PAGE>

                                    ARTICLE 3

                                 THE SECURITIES

Section 3.1  Amount Unlimited; Issuable in Series.

     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. There shall be established in or pursuant to a Board Resolution
and, subject to Section 3.3, set forth, or determined in the manner provided, in
an Officers' Certificate, or established in one or more indentures supplemental
hereto, prior to the issuance of Securities of any series,

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

             (2)   any limit upon the aggregate principal amount of the
     Securities of the series which may be authenticated and delivered under
     this Indenture (except for Securities authenticated and delivered upon
     registration of transfer of, or in exchange for, or in lieu of, other
     Securities of the series pursuant to Section 3.4, 3.5, 3.6, 9.6 or 11.7 and
     except for any Securities which, pursuant to Section 3.3, are deemed never
     to have been authenticated and delivered hereunder);

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

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

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

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

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

             (8)   the obligation, if any, of the Company to redeem or purchase
     any Securities of the series pursuant to any sinking fund or analogous
     provisions or at the option of the Holder

                                                                            -25-

<PAGE>

     thereof and the period or periods within which, the price or prices at
     which and the terms and conditions upon which any Securities of the
     series shall be redeemed or purchased, in whole or in part, pursuant to
     such obligation;

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

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

             (11)  if other than the currency of the United States of America,
     the currency, currencies or currency units in which the principal of or any
     premium or interest on any Securities of the series shall be payable
     and the manner of determining the equivalent thereof in the currency of
     the United States of America for any purpose, including for purposes of
     the definition of "Outstanding" in Section 1.1;

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

             (13)  if other than the entire principal amount thereof, the
     portion of the principal amount of any Securities of the series which shall
     be payable upon declaration of acceleration of the Maturity thereof
     pursuant to Section 5.2;

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

             (15)  if applicable, that the Securities of the series, in whole or
     any specified part, shall be defeasible pursuant to Section 13.2 or Section
     13.3 or both such Sections, or any other defeasance provisions applicable
     to any Securities of the series, and, if other than by a Board Resolution,
     the manner in which any election by the Company to defease such Securities
     shall be evidenced;

             (16)  if applicable, the terms of any right to convert or exchange
     Securities of the series into shares of Common Stock of the Company or
     other securities or property;

                                                                            -26-

<PAGE>

             (17)   if applicable, that any Securities of the series shall be
     issuable in whole or in part in the form of one or more Global Securities
     and, in such case, the respective Depositaries for such Global Securities,
     the form of any legend or legends which shall be borne by any such Global
     Security in addition to or in lieu of that set forth in Section 2.4 and
     any circumstances in addition to or in lieu of those set forth in Clause
     (2) of the last paragraph of Section 3.5 in which any such Global Security
     may be exchanged in whole or in part for Securities registered, and any
     transfer of such Global Security in whole or in part may be registered, in
     the name or names of Persons other than the Depositary for such Global
     Security or a nominee thereof;

             (18)   any addition to or change in the Events of Default which
     applies to any Securities of the series and any change in the right of the
     Trustee or the requisite Holders of such Securities to declare the
     principal amount thereof due and payable pursuant to Section 5.2;

             (19)   any addition to or change in the covenants set forth in
     Article 10 which applies to Securities of the series;

             (20)   any Authenticating Agents, Paying Agents, Security
     Registrars or such other agents necessary in connection with the issuance
     of the Securities of such series, including, without limitation, exchange
     rate agents and calculation agents;

             (21)   if applicable, the terms of any security that will be
     provided for a series of Securities, including any provisions regarding the
     circumstances under which collateral may be released or substituted;

             (22)   if applicable, the terms of any guaranties for the
     Securities and any circumstances under which there may be additional
     obligors on the Securities;

             (23)   any addition to or change in or modification to the
     subordinated provisions of this Indenture relating to the Securities of
     that series (including the provisions of Article 15), or different
     subordination provisions, including a different definition of "Senior Debt"
     or "Designated Senior Debt," will apply to Securities of the series; and

             (24)   any other terms of the series (which terms shall not be
     inconsistent with the provisions of this Indenture, except as permitted by
     Section 9.1(5)).

     All Securities of any one series shall be substantially identical except as
to denomination and except as may otherwise be provided in or pursuant to the
Board Resolution referred to above and (subject to Section 3.3) set forth, or
determined in the manner provided, in the Officers' Certificate referred to
above or in any such indenture supplemental hereto.

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

     The Securities shall be subordinated in right of payment to Senior Debt as
provided in Article 15.

                                                                            -27-

<PAGE>

Section 3.2  Denominations.

     The Securities of each series shall be issuable only in registered form
without coupons and only in such denominations as shall be specified as
contemplated by Section 3.1. In the absence of any such specified denomination
with respect to the Securities of any series, the Securities of such series
shall be issuable in denominations of $1,000 and any integral multiple thereof.

Section 3.3 Execution, Authentication, Delivery and Dating.

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

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

     At any time and from time to time after the execution and delivery of this
Indenture, the Company may deliver Securities of any series executed by the
Company to the Trustee for authentication, together with a Company Order for the
authentication and delivery of such Securities, and the Trustee in accordance
with the Company Order shall authenticate and deliver such Securities. If the
form or terms of the Securities of the series have been established by or
pursuant to one or more Board Resolutions as permitted by Sections 2.1 and 3.1,
in authenticating such Securities, and accepting the additional responsibilities
under this Indenture in relation to such Securities, the Trustee shall be
entitled to receive, and (subject to Section 6.1) shall be fully protected in
relying upon, a copy of such Board Resolution, the Officers' Certificate setting
forth the terms of the series and an Opinion of Counsel, with such Opinion of
Counsel stating,

             (1)   if the form of such Securities has been established by or
     pursuant to Board Resolution as permitted by Section 2.1, that such form
     has been established in conformity with the provisions of this Indenture;

             (2)   if the terms of such Securities have been established by or
     pursuant to Board Resolution as permitted by Section 3.1, that such terms
     have been established in conformity with the provisions of this Indenture;
     and

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

                                                                            -28-

<PAGE>

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

     Notwithstanding the provisions of Section 3.1 and of the preceding
paragraph, if all Securities of a series are not to be originally issued at one
time, it shall not be necessary to deliver the Officers' Certificate otherwise
required pursuant to Section 3.1 or the Company Order and Opinion of Counsel
otherwise required pursuant to such preceding paragraph at or prior to the
authentication of each Security of such series if such documents are delivered
at or prior to the authentication upon original issuance of the first Security
of such series to be issued.

     Each Security shall be dated the date of its authentication.

     No Security shall be entitled to any benefit under this Indenture or be
valid or obligatory for any purpose unless there appears on such Security a
certificate of authentication substantially in the form provided for herein
executed by the Trustee by manual signature, and such certificate upon any
Security shall be conclusive evidence, and the only evidence, that such Security
has been duly authenticated and delivered hereunder. Notwithstanding the
foregoing, if any Security shall have been authenticated and delivered hereunder
but never issued and sold by the Company, and the Company shall deliver such
Security to the Trustee for cancellation as provided in Section 3.9, for all
purposes of this Indenture such Security shall be deemed never to have been
authenticated and delivered hereunder and shall never be entitled to the
benefits of this Indenture.

     Neither the Company nor the Trustee shall have any responsibility for any
defect in the CUSIP number that appears on any Security, check, advice of
payment or redemption notice, and any such document may contain a statement to
the effect that CUSIP numbers have been assigned by an independent service for
convenience of reference and that neither the Company nor the Trustee shall be
liable for any inaccuracy in such numbers.

Section 3.4  Temporary Securities.

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

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

                                                                            -29-

<PAGE>

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

Section 3.5 Registration; Registration of Transfer and Exchange.

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

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

     At the option of the Holder, Securities of any series may be exchanged for
other Securities of the same series, of any authorized denominations and of like
tenor and aggregate principal amount, upon surrender of the Securities to be
exchanged at such office or agency. Whenever any Securities are so surrendered
for exchange, the Company shall execute, and the Trustee shall authenticate and
deliver, the Securities that the Holder making the exchange is entitled to
receive. All Securities issued upon any registration of transfer or exchange of
Securities shall be the valid obligations of the Company, evidencing the same
debt, and entitled to the same benefits under this Indenture, as the Securities
surrendered upon such registration of transfer or exchange.

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

     No service charge shall be made for any registration of transfer or
exchange of Securities, but the Company may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in connection
with any registration of transfer or exchange of Securities, other than
exchanges pursuant to Section 3.4, 9.6 or 11.7 not involving any transfer.

     If the Securities of any series (or of any series and specified tenor) are
to be redeemed in part, the Company shall not be required (A) to issue, register
the transfer of or exchange any Securities of that series (or of that series and
specified tenor, as the case may be) during a period beginning at the opening of
business 15 days before the day of the mailing of a notice of redemption of any
such Securities selected for redemption under Section 11.3 and ending at the
close of business on the day

                                                                            -30-

<PAGE>

of such mailing, or (B) to register the transfer of or exchange any Security so
selected for redemption in whole or in part, except the unredeemed portion of
any Security being redeemed in part.

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

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

             (2)  Notwithstanding any other provision in this Indenture, no
     Global Security may be exchanged in whole or in part for Securities
     registered, and no transfer of a Global Security in whole or in part may be
     registered, in the name of any Person other than the Depositary for such
     Global Security or a nominee thereof unless (A) such Depositary (i) has
     notified the Company that it is unwilling or unable to continue as
     Depositary for such Global Security or (ii) has ceased to be a clearing
     agency registered under the Exchange Act, (B) there shall have occurred and
     be continuing an Event of Default with respect to such Global Security or
     (C) there shall exist such circumstances, if any, in addition to or in lieu
     of the foregoing as have been specified for this purpose as contemplated by
     Section 3.1.

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

             (4)  Every Security authenticated and delivered upon registration
     of transfer of, or in exchange for or in lieu of, a Global Security or any
     portion thereof, whether pursuant to this Section, Section 3.4, 3.6, 9.6 or
     11.7 or otherwise, shall be authenticated and delivered in the form of, and
     shall be, a Global Security, unless such Security is registered in the name
     of a Person other than the Depositary for such Global Security or a nominee
     thereof.

Section 3.6  Mutilated, Destroyed, Lost and Stolen Securities.

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

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

                                                                            -31-

<PAGE>

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

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

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

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

Section 3.7 Payment of Interest; Interest Rights Preserved.

     Except as otherwise provided as contemplated by Section 3.1 with respect to
any series of Securities, interest on any Security which is payable, and is
punctually paid or duly provided for, on any Interest Payment Date shall be paid
to the Person in whose name that Security (or one or more Predecessor
Securities) is registered at the close of business on the Regular Record Date
for such interest.

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

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

                                                                            -32-

<PAGE>

     days and not less than 10 days prior to the date of the propose
     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
     given to each Holder of Securities of such series in the manner set
     forth in Section 1.6, not less than 10 days prior to such Special
     Record Date. Notice of the proposed payment of such Defaulted Interest
     and the Special Record Date therefor having been so mailed, such
     Defaulted Interest shall be paid to the Persons in whose names the
     Securities of such series (or their respective Predecessor Securities)
     are registered at the close of business on such Special Record Date and
     shall no longer be payable pursuant to the following Clause (2).

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

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

     Subject to the provisions of Section 14.2, in the case of any Security (or
any part thereof) which is converted after any Regular Record Date and on or
prior to the next succeeding Interest Payment Date (other than any Security the
principal of (or premium, if any, on) which shall become due and payable,
whether at Stated Maturity or by declaration of acceleration or otherwise prior
to such Interest Payment Date), interest whose Stated Maturity is on such
Interest Payment Date shall be payable on such Interest Payment Date
notwithstanding such conversion and such interest (whether or not punctually
paid or duly provided for) shall be paid to the Person in whose name that
Security (or any one or more Predecessor Securities) is registered at the close
of business on such Regular Record Date. Except as otherwise expressly provided
in the immediately preceding sentence or in Section 14.2, in the case of any
Security (or any part thereof) which is converted, interest whose Stated
Maturity is after the date of conversion of such Security (or such part thereof)
shall not be payable.

Section 3.8  Persons Deemed Owners.

     Prior to due presentment of a Security for registration of transfer, the
Company, the Trustee and any agent of the Company or the Trustee may treat the
Person in whose name such Security is registered as the owner of such Security
for the purpose of receiving payment of principal of and any premium and
(subject to Section 3.7) any interest on such Security and for all other
purposes whatsoever, whether or not such Security be overdue, and neither the
Company, the Trustee nor any agent of the Company or the Trustee shall be
affected by notice to the contrary.

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<PAGE>

Section 3.9  Cancellation.

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

Section 3.10 Computation of Interest.

     Except as otherwise specified as contemplated by Section 3.1 for Securities
of any series, interest on the Securities of each series shall be computed on
the basis of a 360-day year of twelve 30-day months.

                                    ARTICLE 4

                           SATISFACTION AND DISCHARGE

Section 4.1  Satisfaction and Discharge of Indenture.

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

             (1)   either

                   (A)  all Securities theretofore authenticated and delivered
             (other than (i) Securities which have been destroyed, lost or
             stolen and which have been replaced or paid as provided in Section
             3.6 and (ii) Securities for whose payment money has theretofore
             been deposited in trust or segregated and held in trust by the
             Trustee or the Company and thereafter repaid to the Company or
             discharged from such trust, as provided in Section 10.3) have been
             delivered to the Trustee for cancellation; or

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

                        (i)   have become due and payable, or

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<PAGE>

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

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

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

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

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

     Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Company to the Trustee under Section 6.7, the obligations of
the Trustee to any Authenticating Agent under Section 6.14 and, if money shall
have been deposited with the Trustee pursuant to subclause (B) of Clause (1) of
this Section, the obligations of the Trustee under Section 4.2 and the last
paragraph of Section 10.3 shall survive.

Section 4.2  Application of Trust Money.

     Subject to the provisions of the last paragraph of Section 10.3, all money
deposited with the Trustee pursuant to Section 4.1 shall be held in trust and
applied by it, in accordance with the provisions of the Securities and this
Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the Persons entitled thereto, of the principal and any premium and
interest for whose payment such money has been deposited with the Trustee.

                                    ARTICLE 5

                                    REMEDIES

Section 5.1  Events of Default.

     "Event of Default," wherever used herein with respect to Securities of any
series, means any one of the following events (whatever the reason for such
Event of Default and whether it shall be occasioned by the provisions of Article
15 or be voluntary or involuntary or be effected by operation

                                                                            -35-

<PAGE>

of law or pursuant to any judgment, decree or order of any court or any order,
rule or regulation of any administrative or governmental body), unless in the
Board Resolution, supplemental indenture or Officers' Certificate establishing
such series, it is provided that such series shall not have the benefit of said
Event of Default:

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

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

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

             (4)   default in the performance, or breach, of any covenant or
         warranty of the Company in this Indenture (other than a covenant or
         warranty a default in whose performance or whose breach is elsewhere in
         this Section specifically dealt with or which has expressly been
         included in this Indenture solely for the benefit of series of
         Securities other than that series), and continuance of such default or
         breach for a period of 90 days after there has been given, by
         registered or certified mail, to the Company by the Trustee or to the
         Company and the Trustee by the Holders of at least 25% in principal
         amount of the Outstanding Securities of that series a written notice
         specifying such default or breach and requiring it to be remedied and
         stating that such notice is a "Notice of Default" hereunder; or

             (5)   the entry by a court having jurisdiction in the premises of
         (A) a decree or order for relief in respect of the Company in an
         involuntary case or proceeding under any applicable Federal or State
         bankruptcy, insolvency, reorganization or other similar law or (B) a
         decree or order adjudging the Company a bankrupt or insolvent, or
         approving as properly filed a petition seeking reorganization,
         arrangement, adjustment or composition of or in respect of the Company
         under any applicable Federal or State law, or appointing a custodian,
         receiver, liquidator, assignee, trustee, sequestrator or other similar
         official of the Company or of any substantial part of its property, or
         ordering the winding up or liquidation of its affairs, and the
         continuance of any such decree or order for relief or any such other
         decree or order unstayed and in effect for a period of 90 consecutive
         days; or

             (6)   the commencement by the Company of a voluntary case or
         proceeding under any applicable Federal or State bankruptcy,
         insolvency, reorganization or other similar law or of any other case or
         proceeding to be adjudicated a bankrupt or insolvent, or the consent by
         it to the entry of a decree or order for relief in respect of the
         Company in an involuntary case or proceeding under any applicable
         Federal or State bankruptcy, insolvency, reorganization or other
         similar law or to the commencement of any bankruptcy or insolvency case
         or proceeding against it, or the filing by it of a petition or answer
         or consent seeking reorganization or relief under any applicable
         Federal or State law, or the consent by it to the filing of such
         petition or to the appointment of or taking possession by a custodian,
         receiver, liquidator, assignee, trustee, sequestrator or other similar
         official of the Company or of any

                                                                            -36-

<PAGE>

     substantial part of its property, or the making by it of an assignment for
     the benefit of creditors, or the admission by it in writing of its
     inability to pay its debts generally as they become due, or the taking of
     corporate action by the Company in furtherance of any such action; or

          (7)  any other Event of Default provided with respect to Securities of
     that series in the Board Resolution, supplemental indenture or Officers'
     Certificate establishing that series.

Section 5.2  Acceleration of Maturity; Rescission and Annulment.

     Unless the Board Resolution, supplemental indenture or Officers'
Certificate establishing such series provides otherwise, if an Event of Default
(other than an Event of Default specified in Section 5.1(5) or 5.1(6)) with
respect to Securities of any series at the time Outstanding occurs and is
continuing, then in every such case the Trustee or the Holders of not less than
25% in principal amount of the Outstanding Securities of that series may declare
the principal amount of all the Securities of that series (or, if any Securities
of that series are Original Issue Discount Securities, such portion of the
principal amount of such Securities as may be specified by the terms thereof)
and premium, if any, together with accrued and unpaid interest, if any, thereon
to be due and payable immediately, by a notice in writing to the Company (and to
the Trustee if given by the Holders), and upon any such declaration such
principal amount (or specified amount) and premium, if any, together with
accrued and unpaid interest, if any, thereon shall become immediately due and
payable. If an Event of Default specified in Section 5.1(5) or 5.1(6) with
respect to Securities of any series at the time Outstanding occurs, the
principal amount of all the Securities of that series (or, if any Securities of
that series are Original Issue Discount Securities, such portion of the
principal amount of such Securities as may be specified by the terms thereof)
and premium, if any, together with accrued and unpaid interest, if any, thereon
shall automatically, and without any declaration or other action on the part of
the Trustee or any Holder, become immediately due and payable. Any payments by
the Company on the Securities following any such acceleration will be subject to
the subordination provisions of Article 15 to the extent provided therein.

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

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

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

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

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

                                                                            -37-

<PAGE>

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

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

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

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

     The Company covenants that if

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

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

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

Section 5.4  Trustee May File Proofs of Claim.

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

                                                                            -38-

<PAGE>

Trustee, its agents and counsel, and any other amounts due the Trustee under
Section 6.7. No provision of this Indenture shall be deemed to authorize the
Trustee to authorize or consent to or accept or adopt on behalf of any Holder
any plan of reorganization, arrangement, adjustment or composition affecting the
Securities or the rights of any Holder thereof or to authorize the Trustee to
vote in respect of the claim of any Holder in any such proceeding; provided,
                                                                   --------
however, that the Trustee may, on behalf of the Holders, vote for the election
-------
of a trustee in bankruptcy or similar official and be a member of a creditors'
or other similar committee.

Section 5.5  Trustee May Enforce Claims Without Possession of Securities.

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

Section 5.6  Application of Money Collected.

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

     FIRST: To the payment of all amounts due the Trustee under Section 6.7;

     SECOND: Subject to Article 15, to the payment of the amounts then due and
unpaid for principal of and any premium, if any, and interest on the Securities
in respect of which or for the benefit of which such money has been collected,
ratably, without preference or priority of any kind, according to the amounts
due and payable on such Securities for principal and any premium, if any, and
interest, respectively; and

     THIRD: The balance, if any, to the Company or any other Person or Persons
entitled thereto.

Section 5.7  Limitation on Suits.

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

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

                                                                            -39-

<PAGE>

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

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

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

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

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

Section 5.8  Unconditional Right of Holders to Receive Principal, Premium and
Interest and to Convert.

     Notwithstanding any other provision in this Indenture, the Holder of any
Security shall have the right, which is absolute and unconditional, to receive
payment of the principal of and any premium and (subject to Section 3.7)
interest on such Security on the respective Stated Maturities expressed in such
Security (or, in the case of redemption, on the Redemption Date), to convert
such Securities in accordance with Article 14 to the extent that such right to
convert is applicable to such Security, and to institute suit for the
enforcement of any such payment, and such rights shall not be impaired without
the consent of such Holder.

Section 5.9  Restoration of Rights and Remedies.

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

Section 5.10 Rights and Remedies Cumulative.

     Except as otherwise provided with respect to the replacement or payment of
mutilated, destroyed, lost or stolen Securities in the last paragraph of Section
3.6, no right or remedy herein conferred upon or reserved to the Trustee or to
the Holders is intended to be exclusive of any other

                                                                            -40-

<PAGE>

right or remedy, and every right and remedy shall, to the extent permitted by
law, be cumulative and in addition to every other right and remedy given
hereunder or now or hereafter existing at law or in equity or otherwise. The
assertion or employment of any right or remedy hereunder, or otherwise, shall
not prevent the concurrent assertion or employment of any other appropriate
right or remedy.

Section 5.11 Delay or Omission Not Waiver.

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

Section 5.12 Control by Holders.

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

          (1) such direction shall not be in conflict with any rule of law or
     with this Indenture and the Trustee shall not have determined that the
     action so directed would be unjustly prejudicial to Holders of Securities
     of that series, or any other series, not taking part in such direction; and

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

Section 5.13 Waiver of Past Defaults.

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

          (1) a default in the payment of the principal of or any premium or
     interest on any Security of such series as and when the same shall become
     due and payable by the terms thereof, otherwise than by acceleration
     (unless such default has been cured and a sum sufficient to pay all matured
     installments of interest, principal and premium, if any, has been deposited
     with the Trustee), or

          (2) to the extent such right is applicable to such Security, a failure
     by the Company on request to convert any Security into Common Stock; or

          (3) in respect of a covenant or provision hereof which under Article 9
     cannot be modified or amended without the consent of the Holder of each
     Outstanding Security of such series affected.

                                                                            -41-

<PAGE>

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

Section 5.14 Undertaking for Costs.

     In any suit for the enforcement of any right or remedy under this
Indenture, or in any suit against the Trustee for any action taken, suffered or
omitted by it as Trustee, a court may require any party litigant in such suit to
file an undertaking to pay the costs of such suit, and may assess costs against
any such party litigant, in the manner and to the extent provided in the Trust
Indenture Act; provided that neither this Section nor the Trust Indenture Act
shall be deemed to authorize any court to require such an undertaking or to make
such an assessment in any suit instituted by the Company or in any suit for the
enforcement of the right to convert any Security in accordance with Article 14.

Section 5.15 Waiver of Usury, Stay or Extension Laws.

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

                                   ARTICLE 6

                                  THE TRUSTEE

Section 6.1  Certain Duties and Responsibilities.

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

Section 6.2  Notice of Defaults.

     If a default occurs hereunder with respect to Securities of any series, the
Trustee shall give the Holders of Securities of such series notice of such
default as and to the extent provided by the Trust Indenture Act; provided,
                                                                  --------
however, that except in the case of a default in the payment of principal of (or
-------
premium, if any) or interest on any Securities of such series or in the payment
of any

                                                                            -42-

<PAGE>

sinking fund installment or any conversion right applicable to Securities of
such series, the Trustee shall be protected in withholding such notice if and so
long as 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
interests of the holders of Securities of such series; provided, further,
                                                       --------  -------
however, that in the case of any default of the character specified in Section
-------
5.1(4) with respect to Securities of such series, no such notice to Holders
shall be given until at least 60 days after the occurrence thereof. For the
purpose of this Section, the term "default" means any event that is, or after
notice or lapse of time or both would become, an Event of Default with respect
to Securities of such series.

     Except with respect to Section 10.1, the Trustee shall have no duty to
inquire as to the performance of the Company with respect to the covenants
contained in Article 10. In addition, the Trustee shall not be deemed to have
knowledge of an Event of Default except (i) any Default or Event of Default
occurring pursuant to Sections 5.1(1), 5.1(2) and 5.1(3) (defaults in payments
on the Securities) or (ii) any Default or Event of Default of which the Trustee
shall have received written notification or obtained actual knowledge.

     Delivery of reports, information and documents to the Trustee under Section
7.4 is for informational purposes only 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 hereunder (as to which the
Trustee is entitled to rely conclusively on Officers' Certificates).

Section 6.3  Certain Rights of Trustee.

     Subject to the provisions of Section 6.1:

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

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

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

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

                                                                            -43-

<PAGE>

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

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

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

Section 6.4  Not Responsible for Recitals or Issuance of Securities.

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

Section 6.5  May Hold Securities and Act as Trustee under Other Indentures.

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

     Subject to the limitations imposed by the Trust Indenture Act, nothing in
this Indenture shall prohibit the Trustee from becoming and acting as trustee
under other indentures under which other securities, or certificates of interest
of participation in other securities, of the Company are outstanding in the same
manner as if it were not Trustee hereunder.

                                                                            -44-

<PAGE>

Section 6.6  Money Held in Trust.

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

Section 6.7 Compensation and Reimbursement.

     The Company agrees:

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

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

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

     When the Trustee incurs expenses or renders services after an Event of
Default specified in Section 5.1(5) or 5.1(6) hereof occurs, the expenses and
the compensation for the services (including the fees and expenses of its agents
and counsel) are intended to constitute expenses of administration under any
applicable bankruptcy, insolvency, reorganization or similar law.

Section 6.8  Conflicting Interests.

     If the Trustee has or shall acquire a conflicting interest within the
meaning of the Trust Indenture Act, the Trustee shall either eliminate such
interest or resign, to the extent and in the manner provided by, and subject to
the provisions of, the Trust Indenture Act and this Indenture. To the extent
permitted by the Trust Indenture Act, the Trustee shall not be deemed to have a
conflicting interest by virtue of being a trustee under this Indenture with
respect to Securities of more than one series.

Section 6.9  Corporate Trustee Required; Eligibility.

     There shall at all times be one (and only one) Trustee hereunder with
respect to the Securities of each series, which may be Trustee hereunder for
Securities of one or more other series. Each Trustee shall be a Person that is
eligible pursuant to the Trust Indenture Act to act as such and has

                                                                            -45-

<PAGE>

(or if the Trustee is a member of a bank holding company system, its bank
holding company has) a combined capital and surplus of at least $50,000,000. If
any such Person or bank holding company publishes reports of condition at least
annually, pursuant to law or to the requirements of its supervising or examining
authority, then for the purposes of this Section and to the extent permitted by
the Trust Indenture Act, the combined capital and surplus of such Person or bank
holding company shall be deemed to be its combined capital and surplus as set
forth in its most recent report of condition so published. If at any time the
Trustee with respect to the Securities of any series shall cease to be eligible
in accordance with the provisions of this Section, it shall resign immediately
in the manner and with the effect hereinafter specified in this Article.

Section 6.10 Resignation and Removal; Appointment of Successor.

     No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee in accordance with the applicable
requirements of Section 6.11. The Trustee may resign at any time with respect to
the Securities of one or more series by giving written notice thereof to the
Company. If the instrument of acceptance by a successor Trustee required by
Section 6.11 shall not have been delivered to the Trustee within 30 days after
the giving of such notice of resignation, the resigning Trustee may petition any
court of competent jurisdiction for the appointment of a successor Trustee with
respect to the Securities of such series.

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

     If at any time:

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

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

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

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

                                                                            -46-

<PAGE>

     If the Trustee shall resign, be removed or become incapable of acting, or
if a vacancy shall occur in the office of Trustee for any cause, with respect to
the Securities of one or more series, the Company, by a Board Resolution, shall
promptly appoint a successor Trustee or Trustees with respect to the Securities
of that or those series (it being understood that any such successor Trustee may
be appointed with respect to the Securities of one or more or all of such series
and that at any time there shall be only one Trustee with respect to the
Securities of any particular series) and shall comply with the applicable
requirements of Section 6.11. If, within one year after such resignation,
removal or incapability, or the occurrence of such vacancy, a successor Trustee
with respect to the Securities of any series shall be appointed by Act of the
Holders of a majority in principal amount of the Outstanding Securities of such
series delivered to the Company and the retiring Trustee, the successor Trustee
so appointed shall, forthwith upon its acceptance of such appointment in
accordance with the applicable requirements of Section 6.11, become the
successor Trustee with respect to the Securities of such series and to that
extent supersede the successor Trustee appointed by the Company. If no successor
Trustee with respect to the Securities of any series shall have been so
appointed by the Company or the Holders and accepted appointment in the manner
required by Section 6.11, the retiring Trustee may petition, or any Holder who
has been a bona fide Holder of a Security of such series for at least six months
may petition, on behalf of himself and all others similarly situated, any court
of competent jurisdiction for the appointment of a successor Trustee with
respect to the Securities of such series.

     The Company shall give notice of each resignation and each removal of the
Trustee with respect to the Securities of any series and each appointment of a
successor Trustee with respect to the Securities of any series to all Holders of
Securities of such series in the manner provided in Section 1.6. Each notice
shall include the name of the successor Trustee with respect to the Securities
of such series and the address of its Corporate Trust Office.

Section 6.11 Acceptance of Appointment by Successor.

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

     In case of the appointment hereunder of a successor Trustee with respect to
the Securities of one or more (but not all) series, the Company, the retiring
Trustee and each successor Trustee with respect to the Securities of one or more
series shall execute and deliver an indenture supplemental hereto wherein each
successor Trustee shall accept such appointment and which (1) shall contain such
provisions as shall be necessary or desirable to transfer and confirm to, and to
vest in, each

                                                                            -47-

<PAGE>

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

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

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

Section 6.12 Merger, Conversion, Consolidation or Succession to Business.

     Any corporation into which the Trustee may be merged or converted or with
which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all the corporate trust business
of the Trustee (including the administration of the trust created by this
Indenture), shall be the successor of the Trustee hereunder, provided such
corporation shall be otherwise qualified and eligible under this Article,
without the execution or filing of any paper or any further act on the part of
any of the parties hereto. In case any Securities shall have been authenticated,
but not delivered, by the Trustee then in office, any successor by merger,
conversion or consolidation to such authenticating Trustee may adopt such
authentication and deliver the Securities so authenticated with the same effect
as if such successor Trustee had itself authenticated such Securities. In the
event that any Securities shall not have been authenticated by such predecessor
Trustee, any such successor trustee may authenticate and deliver such Securities
in either its own name or that of a predecessor Trustee, with the full force and
effect which this Indenture provides for the certificate of authentication of
the Trustee.

Section 6.13 Preferential Collection of Claims Against Company.

     If and when the Trustee shall be or become a creditor of the Company (or
any other obligor upon the Securities), the Trustee shall be subject to the
provisions of the Trust Indenture Act regarding the collection of claims against
the Company (or any such other obligor).

                                                                            -48-

<PAGE>

Section 6.14 Appointment of Authenticating Agent.

     The Trustee may appoint an Authenticating Agent or Agents with respect to
one or more series of Securities which shall be authorized to act on behalf of
the Trustee to authenticate Securities of such series issued upon original issue
and upon exchange, registration of transfer or partial redemption thereof or
pursuant to Section 3.6, and Securities so authenticated shall be entitled to
the benefits of this Indenture and shall be valid and obligatory for all
purposes as if authenticated by the Trustee hereunder. Wherever reference is
made in this Indenture to the authentication and delivery of Securities by the
Trustee or the Trustee's certificate of authentication, such reference shall be
deemed to include authentication and delivery on behalf of the Trustee by an
Authenticating Agent and a certificate of authentication executed on behalf of
the Trustee by an Authenticating Agent. Each Authenticating Agent shall be
acceptable to the Company and shall at all times be a corporation organized and
doing business under the laws of the United States of America, any state thereof
or the District of Columbia, authorized under such laws to act as Authenticating
Agent, having (or if the Authenticating Agent is a member of a bank holding
company system, its bank holding company has) a combined capital and surplus of
not less than $50,000,000 and subject to supervision or examination by federal
or state authority. If such Authenticating Agent publishes reports of condition
at least annually, pursuant to law or to the requirements of said supervising or
examining authority, then for the purposes of this Section, the combined capital
and surplus of such Authenticating Agent shall be deemed to be its combined
capital and surplus as set forth in its most recent report of condition so
published. If at any time an Authenticating Agent shall cease to be eligible in
accordance with the provisions of this Section, such Authenticating Agent shall
resign immediately in the manner and with the effect specified in this Section.

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

     An Authenticating Agent may resign at any time by giving written notice
thereof to the Trustee and to the Company. The Trustee may at any time terminate
the agency of an Authenticating Agent by giving written notice thereof to such
Authenticating Agent and to the Company. Upon receiving such a notice of
resignation or upon such a termination, or in case at any time such
Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent which shall be acceptable to the Company and shall give notice of such
appointment in the manner provided in Section 1.6 to all Holders of Securities
of the series with respect to which such Authenticating Agent will serve. Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, with like effect as if originally named as an Authenticating Agent.
No successor Authenticating Agent shall be appointed unless eligible under the
provisions of this Section.

                                                                            -49-

<PAGE>

     The Trustee agrees to pay to each Authenticating Agent from time to time
reasonable compensation for its services under this Section, and the Trustee
shall be entitled to be reimbursed for such payments, subject to the provisions
of Section 6.7.

     If an appointment with respect to one or more series is made pursuant to
this Section 6.12, the Securities of such series may have endorsed thereon, in
lieu of the Trustee's certificate of authentication, an alternative certificate
of authentication in the following form:

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

                                           U.S. Bank National Association

                                           By: _________________________________
                                               As Authenticating Agent

                                           By: _________________________________
                                               Authorized Officer

                                   ARTICLE 7

               HOLDERS' LISTS AND REPORTS BY TRUSTEE AND COMPANY

Section 7.1  Company to Furnish Trustee Names and Addresses of Holders.

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

          (1) semi-annually, not later than 15 days after the Regular Record
     Date for each respective series of Securities, a list, in such form as the
     Trustee may reasonably require, of the names and addresses of the Holders
     of Securities of each series as of such Regular Record Date, as the case
     may be, or if there is no Regular Record Date for such series of
     Securities, semiannually and

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

provided that no such list need be furnished by the Company to the Trustee so
long as the Trustee is acting as Security Registrar.

Section 7.2 Preservation of Information; Communications to Holders.

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

                                                                            -50-

<PAGE>

     The rights of Holders to communicate with other Holders with respect to
their rights under this Indenture or under the Securities, and the corresponding
rights and privileges of the Trustee, shall be as provided by the Trust
Indenture Act. Every Holder of Securities, by receiving and holding the same,
agrees with the Company and the Trustee that neither the Company nor the Trustee
nor any agent of either of them shall be held accountable by reason of any
disclosure of information as to names and addresses of Holders made pursuant to
the Trust Indenture Act.

Section 7.3  Reports by Trustee.

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

     Reports so required to be transmitted at stated intervals of not more than
12 months shall be transmitted no later than July 15 in each calendar year,
commencing with the first July 15 after the first issuance of Securities
pursuant to this Indenture.

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

Section 7.4  Reports by Company.

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

                                    ARTICLE 8

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

Section 8.1  Company May Consolidate, etc., Only on Certain Terms.

     The Company shall not consolidate with or merge into any other Person (in a
transaction in which the Company is not the surviving corporation) or convey,
transfer or lease its properties and assets substantially as an entirety to any
Person, unless:

          (1) in case the Company shall consolidate with or merge into another
     Person (in a transaction in which the Company is not the surviving
     corporation) or convey, transfer or lease its properties and assets
     substantially as an entirety to any Person, the Person formed by such
     consolidation or into which the Company is merged or the Person which
     acquires by

                                                                            -51-

<PAGE>

     conveyance or transfer, or which leases, the properties and assets of the
     Company substantially as an entirety shall be a corporation, limited
     liability company, partnership or trust, shall be organized and validly
     existing under the laws of the United States of America, any state thereof
     or the District of Columbia and shall expressly assume, by an indenture
     supplemental hereto, executed and delivered to the Trustee, in form
     satisfactory to the Trustee, the due and punctual payment of the principal
     of and any premium and interest on all the Securities and the performance
     or observance of every covenant of this Indenture on the part of the
     Company to be performed or observed, and the conversion rights shall be
     provided for in accordance with Article 14, if applicable, or as otherwise
     specified pursuant to Section 3.1, by supplemental indenture satisfactory
     in form to the Trustee, executed and delivered to the Trustee, by the
     Person (if other than the Company) formed by such consolidation or into
     which the Company shall have been merged or by the Person which shall have
     acquired the Company's assets;

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

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

Section 8.2  Successor Substituted.

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

                                                                            -52-

<PAGE>

                                   ARTICLE 9

                             SUPPLEMENTAL INDENTURES

Section 9.1  Supplemental Indentures Without Consent of Holders.

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

          (1) to evidence the succession of another Person to the Company, or
     successive successions, and the assumption by any such successor of the
     covenants of the Company herein and in the Securities in compliance with
     Article 8; or

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

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

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

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

          (6) to secure the Securities, including provisions regarding the
     circumstances under which collateral may be released or substituted; or

          (7) to add or provide for guaranties of the Securities or additional
     obligors on the Securities; or

          (8) to establish the form or terms of Securities of any series as
     permitted by Sections 2.1 and 3.1; or

          (9) to evidence and provide for the acceptance of appointment
     hereunder by a successor Trustee with respect to the Securities of one or
     more series and to add to or change any of the provisions of this Indenture
     as shall be necessary to provide for or facilitate the

                                                                            -53-

<PAGE>

     administration of the trusts hereunder by more than one Trustee, pursuant
     to the requirements of Section 6.11; or

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

          (11) to supplement any of the provisions of the Indenture to such
     extent as shall be necessary to permit or facilitate the defeasance and
     discharge of any series of Securities pursuant to Articles 4 and 13,
     provided that any such action shall not adversely affect the interests of
     the Holders of Securities of such series or any other series of Securities
     in any material respect.

Section 9.2  Supplemental Indentures with Consent of Holders.

     With the consent of the Holders of a majority in principal amount of the
Outstanding Securities of each series affected by such supplemental indenture,
by Act of said Holders delivered to the Company and the Trustee, the Company,
when authorized by a Board Resolution, and the Trustee may enter into an
indenture or indentures supplemental hereto for the purpose of adding any
provisions to or changing in any manner or eliminating any of the provisions of
this Indenture or of modifying in any manner the rights of the Holders of
Securities of such series under this Indenture; provided, however, that no such
                                                --------  -------
supplemental indenture shall, without the consent of the Holder of each
Outstanding Security affected thereby,

          (1) change the Stated Maturity of the principal of, or any installment
     of principal of or interest on, any Security, or reduce the principal
     amount thereof or the rate of interest thereon or any premium payable upon
     the redemption thereof, or reduce the amount of the principal of an
     Original Issue Discount Security or any other Security which would be due
     and payable upon a declaration of acceleration of the Maturity thereof
     pursuant to Section 5.2, or change the coin or currency in which, any
     Security or any premium or interest thereon is payable, or impair the right
     to institute suit for the enforcement of any such payment on or after the
     Stated Maturity thereof (or, in the case of redemption, on or after the
     Redemption Date), or modify the provisions of this Indenture with respect
     to the subordination of such series of Securities in a manner adverse to
     the Holders of Securities of such series, or, in the case of Securities of
     any series that are convertible into Securities or other securities of the
     Company, adversely affect the right of Holders to convert any of the
     Securities of such series other than as provided in or pursuant to this
     Indenture, or

                                                                            -54-

<PAGE>

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

          (3) modify any of the provisions of this Section, Section 5.13 or
     Section 10.8, except to increase any such percentage or to provide that
     certain other provisions of this Indenture cannot be modified or waived
     without the consent of the Holder of each Outstanding Security affected
     thereby; provided, however, that this clause shall not be deemed to require
              --------  -------
     the consent of any Holder with respect to changes in the references to "the
     Trustee" and concomitant changes in this Section and Section 10.8, or the
     deletion of this proviso, in accordance with the requirements of Sections
     6.11 and 9.1(8), or

          (4) if applicable, make any change that adversely affects the right to
     convert any security as provided in Article 14 or pursuant to Section 3.1
     (except as permitted by Section 9.1(9)) or decrease the conversion rate or
     increase the conversion price of any such security.

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

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

Section 9.3  Execution of Supplemental Indentures.

     In executing, or accepting the additional trusts created by, any
supplemental indenture permitted by this Article or the modifications thereby of
the trusts created by this Indenture, the Trustee shall be entitled to receive,
and (subject to Sections 6.1 and 6.3) shall be fully protected in relying upon,
an Opinion of Counsel stating that the execution of such supplemental indenture
is authorized or permitted by this Indenture. The Trustee may, but shall not be
obligated to, enter into any such supplemental indenture which affects the
Trustee's own rights, duties or immunities under this Indenture or otherwise.

Section 9.4  Effect of Supplemental Indentures.

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

                                                                            -55-

<PAGE>

Section 9.5  Conformity with Trust Indenture Act.

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

Section 9.6  Reference in Securities to Supplemental Indentures.

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

Section 9.7  Subordination Unimpaired.

     No provision in any supplemental indenture that affects the superior
position of the holders of Senior Debt shall be effective against holders of
Senior Debt.

                                   ARTICLE 10

                                   COVENANTS

Section 10.1 Payment of Principal, Premium and Interest.

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

Section 10.2 Maintenance of Office or Agency.

     The Company will maintain in each Place of Payment for any series of
Securities an office or agency where Securities of that series may be presented
or surrendered for payment, where Securities of that series may be surrendered
for registration of transfer or exchange, where Securities of that series may be
surrendered for conversion and where notices and demands to or upon the Company
in respect of the Securities of that series and this Indenture may be served.
The Company will give prompt written notice to the Trustee of the location, and
any change in the location, of such office or agency. If at any time the Company
shall fail to maintain any such required office or agency or shall fail to
furnish the Trustee with the address thereof, such presentations, surrenders,
notices and demands may be made or served at the Corporate Trust Office of the
Trustee, and the Company hereby appoints the Trustee as its agent to receive all
such presentations, surrenders, notices and demands. Unless otherwise provided
in a supplemental indenture or pursuant to Section 3.1 hereof, the Place of
Payment for any series of Securities shall be the Corporate Trust Office of the
Trustee.

                                                                            -56-

<PAGE>

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

Section 10.3 Money for Securities Payments to be Held in Trust.

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

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

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

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

     Any money deposited with the Trustee or any Paying Agent, or then held by
the Company, in trust for the payment of the principal of or any premium or
interest on any Security of any series and remaining unclaimed for a period
ending on the earlier of the date that is ten Business Days prior to the date
such money would escheat to the State or two years after such principal, premium
or interest has become due and payable shall be paid to the Company on Company
Request, or (if then held by the Company) shall be discharged from such trust;
and the Holder of such Security shall thereafter,

                                                                            -57-

<PAGE>

as an unsecured general creditor, look only to the Company for payment thereof,
and all liability of the Trustee or such Paying Agent with respect to such trust
money, and all liability of the Company as trustee thereof, shall thereupon
cease; provided, however, that the Trustee or such Paying Agent, before being
       --------  -------
required to make any such repayment, may at the expense of the Company cause to
be published once, in a newspaper published in the English language, customarily
published on each Business Day and of general circulation in each Place of
Payment, notice that such money remains unclaimed and that, after a date
specified therein, which shall not be less than 30 days from the date of such
publication, any unclaimed balance of such money then remaining will be repaid
to the Company.

Section 10.4 Statement by Officers as to Default.

     The Company will deliver to the Trustee, within 120 days after the end of
each fiscal year of the Company ending after the date hereof, an Officers'
Certificate, stating whether or not to the best knowledge of the signers thereof
the Company is in default in the performance and observance of any of the terms,
provisions and conditions of this Indenture (without regard to any period of
grace or requirement of notice provided hereunder) and, if the Company shall be
in default, specifying all such defaults and the nature and status thereof of
which they may have knowledge. The fiscal year of the Company currently ends on
December 31; and the Company will give the Trustee prompt written notice of any
change of its fiscal year.

Section 10.5 Existence.

     Subject to Article 8, the Company will do or cause to be done all things
necessary to preserve and keep in full force and effect its existence.

Section 10.6 Maintenance of Properties.

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

Section 10.7 Payment of Taxes and Other Claims.

     The Company will pay or discharge or cause to be paid or discharged, before
the same shall become delinquent, (1) all taxes, assessments and governmental
charges levied or imposed upon the Company or upon the income, profits or
property of the Company, and (2) all lawful claims for labor, materials and
supplies which, if unpaid, might by law become a lien upon the property of the
Company; provided, however, that the Company shall not be required to pay or
         --------  -------
discharge or cause to

                                                                            -58-

<PAGE>

be paid or discharged any such tax, assessment, charge or claim (i) whose
amount, applicability or validity is being contested in good faith by
appropriate proceedings or (ii) if the failure to pay or discharge would not
have a material adverse effect on the assets, business, operations, properties
or condition (financial or otherwise) of the Company and its subsidiaries, taken
as a whole.

Section 10.8 Waiver of Certain Covenants.

     Except as otherwise specified as contemplated by Section 3.1 for Securities
of such series, the Company may, with respect to the Securities of any series,
omit in any particular instance to comply with any term, provision or condition
set forth in any covenant provided pursuant to Section 3.1(19), 9.1(2), 9.1(7),
10.6 or 10.7 for the benefit of the Holders of such series if before the time
for such compliance the Holders of at least a majority in principal amount of
the Outstanding Securities of such series shall, by Act of such Holders, either
waive such compliance in such instance or generally waive compliance with such
term, provision or condition, but no such waiver shall extend to or affect such
term, provision or condition except to the extent so expressly waived, and,
until such waiver shall become effective, the obligations of the Company and the
duties of the Trustee in respect of any such term, provision or condition shall
remain in full force and effect.

                                   ARTICLE 11

                            REDEMPTION OF SECURITIES

Section 11.1 Applicability of Article.

     Securities of any series that are redeemable before their Stated Maturity
shall be redeemable in accordance with their terms and (except as otherwise
specified as contemplated by Section 3.1 for such Securities) in accordance with
this Article.

Section 11.2 Election to Redeem; Notice to Trustee.

     The election of the Company to redeem any Securities shall be evidenced by
a Board Resolution or in another manner specified as contemplated by Section 3.1
for such Securities. In case of any redemption at the election of the Company of
less than all the Securities of any series (including any such redemption
affecting only a single Security), the Company shall, at least 45 days prior to
the Redemption Date fixed by the Company (unless a shorter notice shall be
satisfactory to the Trustee), notify the Trustee of such Redemption Date, of the
principal amount of Securities of such series to be redeemed and, if applicable,
of the tenor of the Securities to be redeemed. In the case of any redemption of
Securities prior to the expiration of any restriction on such redemption
provided in the terms of such Securities or elsewhere in this Indenture, the
Company shall furnish the Trustee with an Officers' Certificate evidencing
compliance with such restriction.

Section 11.3 Selection by Trustee of Securities to Be Redeemed.

If less than all the Securities of any series are to be redeemed (unless all the
Securities of such series and of a specified tenor are to be redeemed or unless
such redemption affects only a

                                                                            -59-

<PAGE>

single Security), the particular Securities to be redeemed shall be selected not
more than 45 days prior to the Redemption Date by the Trustee, from the
Outstanding Securities of such series not previously called for redemption, by
lot, or in the Trustee's discretion, on a pro-rata basis, provided that the
unredeemed portion of the principal amount of any Security shall be in an
authorized denomination (which shall not be less than the minimum authorized
denomination) for such Security. If less than all the Securities of such series
and of a specified tenor are to be redeemed (unless such redemption affects only
a single Security), the particular Securities to be redeemed shall be selected
not more than 45 days prior to the Redemption Date by the Trustee, from the
Outstanding Securities of such series and specified tenor not previously called
for redemption in accordance with the preceding sentence.

     If any Security selected for partial redemption is converted in part before
termination of the conversion right with respect to the portion of the Security
so selected, the converted portion of such Security shall be deemed (so far as
may be) to be the portion selected for redemption. Securities that have been
converted during a selection of Securities to be redeemed shall be treated by
the Trustee as Outstanding for the purpose of such selection.

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

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

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

Section 11.4 Notice of Redemption.

     Notice of redemption shall be given by first-class mail, postage prepaid,
mailed not fewer than 30 nor more than 60 days prior to the Redemption Date,
unless a shorter period is specified in the Securities to be redeemed, to each
Holder of Securities to be redeemed, at its address appearing in the Security
Register.

     All notices of redemption shall state:

             (1)   the Redemption Date,

             (2)   the Redemption Price (including accrued interest, if any),

                                                                            -60-

<PAGE>

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

           (4) in case any Security is to be redeemed in part only, that on and
     after the Redemption Date, upon surrender of such Security, the Holder of
     such Security will receive, without charge, a new Security or Securities of
     authorized denominations for the principal amount thereof remaining
     unredeemed;

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

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

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

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

           (9) the CUSIP number or numbers and/or common codes of the Security
     being redeemed.

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

Section 11.5 Deposit of Redemption Price.

     On or prior to any Redemption Date, the Company shall deposit with the
Trustee or with a Paying Agent (or, if the Company is acting as its own Paying
Agent, segregate and hold in trust as provided in Section 10.3) an amount of
money sufficient to pay the Redemption Price of, and (except if the Redemption
Date shall be an Interest Payment Date) accrued interest on, all the Securities
which are to be redeemed on that date.

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

Section 11.6 Securities Payable on Redemption Date.

     Notice of redemption having been given as aforesaid, the Securities so to
be redeemed shall, on the Redemption Date, become due and payable at the
Redemption Price therein specified, and from and after such date (unless the
Company shall default in the payment of the Redemption Price and accrued
interest) such Securities shall cease to bear interest. Upon surrender of any
such

                                                                            -61-

<PAGE>

Security for redemption in accordance with said notice, such Security shall be
paid by the Company at the Redemption Price, together with accrued interest to
the Redemption Date; provided, however, that, unless otherwise specified as
                     --------  -------
contemplated by Section 3.1, installments of interest whose Stated Maturity is
on or prior to the Redemption Date will be payable to the Holders of such
Securities, or one or more Predecessor Securities, registered as such at the
close of business on the relevant Record Dates according to their terms and the
provisions of Section 3.7.

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

Section 11.7 Securities Redeemed in Part.

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

                                   ARTICLE 12

                                  SINKING FUNDS

Section 12.1 Applicability of Article.

     The provisions of this Article shall be applicable to any sinking fund for
the retirement of Securities of any series except as otherwise specified as
contemplated by Section 3.1 for such Securities.

     The minimum amount of any sinking fund payment provided for by the terms of
any Securities is herein referred to as a "mandatory sinking fund payment," and
any payment in excess of such minimum amount provided for by the terms of such
Securities is herein referred to as an "optional sinking fund payment." If
provided for by the terms of any Securities, the cash amount of any sinking fund
payment may be subject to reduction as provided in Section 12.2. Each sinking
fund payment shall be applied to the redemption of Securities as provided for by
the terms of such Securities.

Section 12.2 Satisfaction of Sinking Fund Payments with Securities.

     The Company (1) may deliver Outstanding Securities of a series (other than
any previously called for redemption) and (2) may apply as a credit Securities
of a series which have been redeemed either at the election of the Company
pursuant to the terms of such Securities or through the

                                                                            -62-

<PAGE>

application of permitted optional sinking fund payments pursuant to the terms of
such Securities, in each case in satisfaction of all or any part of any sinking
fund payment with respect to any Securities of such series required to be made
pursuant to the terms of such Securities as and to the extent provided for by
the terms of such Securities; provided that the Securities to be so credited
have not been previously so credited. The Securities to be so credited shall be
received and credited for such purpose by the Trustee at the Redemption Price,
as specified in the Securities so to be redeemed, for redemption through
operation of the sinking fund and the amount of such sinking fund payment shall
be reduced accordingly.

Section 12.3 Redemption of Securities for Sinking Fund.

     Not fewer than 60 days prior to each sinking fund payment date for any
Securities, the Company will deliver to the Trustee an Officers' Certificate
specifying the amount of the next ensuing sinking fund payment for such
Securities pursuant to the terms of such Securities, the portion thereof, if
any, which is to be satisfied by payment of cash and the portion thereof, if
any, which is to be satisfied by delivering and crediting Securities pursuant to
Section 12.2 and will also deliver to the Trustee any Securities to be so
delivered. Not fewer than 30 days prior to each such sinking fund payment date,
the Trustee shall select the Securities to be redeemed upon such sinking fund
payment date in the manner specified in Section 11.3 and cause notice of the
redemption thereof to be given in the name of and at the expense of the Company
in the manner provided in Section 11.4. Such notice having been duly given, the
redemption of such Securities shall be made upon the terms and in the manner
stated in Sections 11.6 and 11.7.

                                   ARTICLE 13

                       DEFEASANCE AND COVENANT DEFEASANCE

Section 13.1 Company's Option to Effect Defeasance or Covenant Defeasance.

     The Company may elect, at its option at any time, to have Section 13.2 or
Section 13.3 applied to any Securities or any series of Securities, as the case
may be, designated pursuant to Section 3.1 as being defeasible pursuant to such
Section 13.2 or 13.3, in accordance with any applicable requirements provided
pursuant to Section 3.1 and upon compliance with the conditions set forth below
in this Article. Any such election shall be evidenced by a Board Resolution or
in another manner specified as contemplated by Section 3.1 for such Securities.

Section 13.2 Defeasance and Discharge.

     Upon the Company's exercise of its option (if any) to have this Section
applied to any Securities or any series of Securities, as the case may be, the
Company shall be deemed to have been discharged from its obligations, and the
provisions of Article 15 shall cease to be effective, with respect to such
Securities as provided in this Section on and after the date the conditions set
forth in Section 13.4 are satisfied (hereinafter called "Defeasance"). For this
purpose, such Defeasance means that the Company shall be deemed to have paid and
discharged the entire indebtedness represented by such Securities and to have
satisfied all its other obligations under such Securities

                                                                            -63-

<PAGE>

and this Indenture insofar as such Securities are concerned (and the Trustee, at
the expense of the Company, shall execute proper instruments acknowledging the
same), subject to the following which shall survive until otherwise terminated
or discharged hereunder:

           (1) the rights of Holders of such Securities to receive, solely from
     the trust fund described in Section 13.4 and as more fully set forth in
     such Section, payments in respect of the principal of and any premium and
     interest on such Securities when payments are due,

           (2) the Company's obligations with respect to such Securities under
     Sections 3.4, 3.5, 3.6, 10.2 and 10.3, and, if applicable, Article 14,

           (3) the rights, powers, trusts, duties and immunities of the Trustee
     hereunder, and

           (4) this Article.

     Subject to compliance with this Article, the Company may exercise its
option (if any) to have this Section applied to any Securities notwithstanding
the prior exercise of its option (if any) to have Section 13.3 applied to such
Securities.

Section 13.3 Covenant Defeasance.

     Upon the Company's exercise of its option (if any) to have this Section
applied to any Securities or any series of Securities, as the case may be,

           (1) the Company shall be released from its obligations under Sections
     10.6 and 10.7 and any covenants provided pursuant to Sections 3.1(19),
     9.1(2) or 9.1(7) for the benefit of the Holders of such Securities,

          (2) the occurrence of any event specified in Section 5.1(4) (with
     respect to any of Sections 10.6 and 10.7 and any such covenants provided
     pursuant to Section 3.1(19), 9.1(2) or 9.1(7) and the occurrence of any
     Event of Default specified pursuant to Section 3.1), shall be deemed not to
     be or result in an Event of Default, and

           (3) the provisions of Article 15 shall cease to be effective,

in each case with respect to such Securities or series of Securities as provided
in this Section on and after the date the conditions set forth in Section 13.4
are satisfied (hereinafter called "Covenant Defeasance"). For this purpose, such
Covenant Defeasance means that, with respect to such Securities, the Company may
omit to comply with and shall have no liability in respect of any term,
condition or limitation set forth in any such specified Section (to the extent
so specified in the case of Section 5.1(4) and the occurrence of any Event of
Default specified pursuant to Section 3.1) or Article 15, whether directly or
indirectly by reason of any reference elsewhere herein to any such Section or
Article or by reason of any reference in any such Section or Article to any
other provision herein or in any other document, but the remainder of this
Indenture and such Securities shall be unaffected thereby.

                                                                            -64-

<PAGE>

Section 13.4 Conditions to Defeasance or Covenant Defeasance.

     The following shall be the conditions to the application of Section 13.2 or
Section 13.3 to any Securities or any series of Securities, as the case may be:

           (1) The Company shall irrevocably have deposited or caused to be
     deposited with the Trustee (or another trustee which satisfies the
     requirements contemplated by Section 6.9 and agrees to comply with the
     provisions of this Article applicable to it) as trust funds in trust for
     the purpose of making the following payments, specifically pledged as
     security for, and dedicated solely to, the benefits of the Holders of such
     Securities,

               (A) in the case of Securities of a series denominated in currency
           of the United States of America,

                   (i)   cash in currency of the United States of America in an
               amount, or

                   (ii)  U.S. Government Obligations which through the scheduled
               payment of principal and interest in respect thereof in
               accordance with their terms will provide, not later than one day
               before the due date of any payment, an amount in cash, or

                   (iii) a combination thereof, or

               (B) in the case of Securities of a series denominated in currency
           other than that of the United States of America,

                   (i)   cash in the currency in which such series of Securities
               is denominated in an amount, or

                   (ii)  Foreign Government Obligations which through the
               scheduled payment of principal and interest in respect thereof in
               accordance with their terms will provide, not later than one day
               before the due date of any payment, an amount in cash, or

                   (iii) a combination thereof,

     in each case sufficient, in the opinion of a nationally recognized firm of
     independent public accountants expressed in a written certification thereof
     delivered to the Trustee, to pay and discharge, and which shall be applied
     by the Trustee (or any such other qualifying trustee) to pay and discharge,
     the principal of and any premium and interest on such Securities on the
     respective Stated Maturities, in accordance with the terms of this
     Indenture and such Securities.

                                                                            -65-

<PAGE>

           (2) In the event of an election to have Section 13.2 apply to any
     Securities or any series of Securities, as the case may be, the Company
     shall have delivered to the Trustee an Opinion of Counsel stating that

               (A) the Company has received from, or there has been published
           by, the Internal Revenue Service a ruling or

               (B) since the date of this instrument, there has been a change in
           the applicable Federal income tax law,

     in either case (A) or (B) to the effect that, and based thereon such
     opinion shall confirm that, the Holders of such Securities will not
     recognize gain or loss for federal income tax purposes as a result of the
     deposit, Defeasance and discharge to be effected with respect to such
     Securities and will be subject to federal income tax on the same amount, in
     the same manner and at the same times as would be the case if such deposit,
     Defeasance and discharge were not to occur.

           (3) In the event of an election to have Section 13.3 apply to any
     Securities or any series of Securities, as the case may be, the Company
     shall have delivered to the Trustee an Opinion of Counsel to the effect
     that the Holders of such Securities will not recognize gain or loss for
     federal income tax purposes as a result of the deposit and Covenant
     Defeasance to be effected with respect to such Securities and will be
     subject to federal income tax on the same amount, in the same manner and at
     the same times as would be the case if such deposit and Covenant Defeasance
     were not to occur.

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

           (5) No event which is, or after notice or lapse of time or both would
     become, an Event of Default with respect to such Securities or any other
     Securities shall have occurred and be continuing at the time of such
     deposit or, with regard to any such event specified in Sections 5.1(5) and
     (6), at any time on or prior to the 90th day after the date of such deposit
     (it being understood that this condition shall not be deemed satisfied
     until after such 90th day).

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

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

                                                                            -66-

<PAGE>

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

           (9)  At the time of such deposit,

                (A) no default in the payment of any principal of or premium or
           interest on any Senior Debt shall have occurred and be continuing,

                (B) no event of default with respect to any Senior Debt shall
           have resulted in such Senior Debt becoming, and continuing to be, due
           and payable prior to the date on which it would otherwise have become
           due and payable (unless payment of such Senior Debt has been made or
           duly provided for), and

                (C) no other event of default with respect to any Senior Debt
           shall have occurred and be continuing permitting (after notice or
           lapse of time or both) the holders of such Senior Debt (or a trustee
           on behalf of such holders) to declare such Senior Debt due and
           payable prior to the date on which it would otherwise have become due
           and payable.

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

Section 13.5 Deposited Money, U. S. Government Obligations and Foreign
Government Obligations to be Held in Trust; Miscellaneous Provisions.

     Subject to the provisions of the last paragraph of Section 10.3, all money,
U.S. Government Obligations and Foreign Government Obligations (including the
proceeds thereof) deposited with the Trustee or other qualifying trustee (solely
for purposes of this Section and Section 13.6, the Trustee and any such other
trustee are referred to collectively as the "Trustee") pursuant to Section 13.4
in respect of any Securities shall be held in trust and applied by the Trustee,
in accordance with the provisions of such Securities and this Indenture, to the
payment, either directly or through any such Paying Agent (including the Company
acting as its own Paying Agent) as the Trustee may determine, to the Holders of
such Securities, of all sums due and to become due thereon in respect of
principal and any premium and interest, but money so held in trust need not be
segregated from other funds except to the extent required by law. Money, U.S.
Government Obligations and Foreign Government Obligations so held in trust shall
not be subject to the provisions of Article 15.

     The Company shall pay and indemnify the Trustee against any tax, fee or
other charge imposed on or assessed against the U.S. Government Obligations or
Foreign Government Obligations deposited pursuant to Section 13.4 or the
principal and interest received in respect

                                                                            -67-

<PAGE>

thereof other than any such tax, fee or other charge which by law is for the
account of the Holders of Outstanding Securities.

     Anything in this Article to the contrary notwithstanding, the Trustee shall
deliver or pay to the Company from time to time upon Company Request any money,
U.S. Government Obligations or Foreign Government Obligations held by it as
provided in Section 13.4 with respect to any Securities which, in the opinion of
a nationally recognized firm of independent public accountants expressed in a
written certification thereof delivered to the Trustee, are in excess of the
amount thereof which would then be required to be deposited to effect the
Defeasance or Covenant Defeasance, as the case may be, with respect to such
Securities.

Section 13.6 Reinstatement.

     If the Trustee or the Paying Agent is unable to apply any money in
accordance with this Article with respect to any Securities by reason of any
order or judgment of any court or governmental authority enjoining, restraining
or otherwise prohibiting such application, then the obligations under this
Indenture and such Securities from which the Company has been discharged or
released pursuant to Section 13.2 or 13.3 shall be revived and reinstated as
though no deposit had occurred pursuant to this Article with respect to such
Securities, until such time as the Trustee or Paying Agent is permitted to apply
all money held in trust pursuant to Section 13.5 with respect to such Securities
in accordance with this Article; provided, however, that if the Company makes
                                 --------  -------
any payment of principal of or any premium or interest on any such Security
following such reinstatement of its obligations, the Company shall be subrogated
to the rights (if any) of the Holders of such Securities to receive such payment
from the money so held in trust.

                                   ARTICLE 14

                            CONVERSION OF SECURITIES

Section 14.1 Applicability of Article.

     The provisions of this Article shall be applicable to the Securities of any
series which are convertible into shares of Common Stock of the Company, and the
issuance of such shares of Common Stock upon the conversion of such Securities,
except as otherwise specified as contemplated by Section 3.1 for the Securities
of such series.

Section 14.2 Exercise of Conversion Privilege.

     In order to exercise a conversion privilege, the Holder of a Security of a
series with such a privilege shall surrender such Security to the Company at the
office or agency maintained for that purpose pursuant to Section 10.2,
accompanied by a duly executed conversion notice to the Company substantially in
the form set forth in Section 2.6 stating that the Holder elects to convert such
Security or a specified portion thereof. Such notice shall also state, if
different from the name and address of such Holder, the name or names (with
address) in which the certificate or certificates for shares of Common Stock,
which shall be issuable on such conversion, shall be issued. Securities

                                                                            -68-

<PAGE>

surrendered for conversion shall (if so required by the Company or the Trustee)
be duly endorsed by or accompanied by instruments of transfer in forms
satisfactory to the Company and the Trustee duly executed by the Holder or its
attorney duly authorized in writing; and Securities so surrendered for
conversion (in whole or in part) during the period from the close of business on
any Regular Record Date to the opening of business on the next succeeding
Interest Payment Date (excluding Securities or portions thereof called for
redemption during the period beginning at the close of business on a Regular
Record Date and ending at the opening of business on the first Business Day
after the next succeeding Interest Payment Date, or if such Interest Payment
Date is not a Business Day, the second such Business Day) shall also be
accompanied by payment in funds acceptable to the Company of an amount equal to
the interest payable on such Interest Payment Date on the principal amount of
such Security then being converted, and such interest shall be payable to such
Holder notwithstanding the conversion of such Security, subject to the
provisions of Section 3.7 relating to the payment of Defaulted Interest by the
Company. As promptly as practicable after the receipt of such notice and of any
payment required pursuant to a Board Resolution and, subject to Section 3.3, set
forth, or determined in the manner provided, in an Officers' Certificate, or
established in one or more indentures supplemental hereto setting forth the
terms of such series of Security, and the surrender of such Security in
accordance with such reasonable regulations as the Company may prescribe, the
Company shall issue and shall deliver, at the office or agency at which such
Security is surrendered, to such Holder or on its written order, a certificate
or certificates for the number of full shares of Common Stock issuable upon the
conversion of such Security (or specified portion thereof), in accordance with
the provisions of such Board Resolution, Officers' Certificate or supplemental
indenture, and cash as provided therein in respect of any fractional share of
such Common Stock otherwise issuable upon such conversion. Such conversion shall
be deemed to have been effected immediately prior to the close of business on
the date on which such notice and such payment, if required, shall have been
received in proper order for conversion by the Company and such Security shall
have been surrendered as aforesaid (unless such Holder shall have so surrendered
such Security and shall have instructed the Company to effect the conversion on
a particular date following such surrender and such Holder shall be entitled to
convert such Security on such date, in which case such conversion shall be
deemed to be effected immediately prior to the close of business on such date)
and at such time the rights of the Holder of such Security as such Security
Holder shall cease and the person or persons in whose name or names any
certificate or certificates for shares of Common Stock of the Company shall be
issuable upon such conversion shall be deemed to have become the Holder or
Holders of record of the shares represented thereby. Except as set forth above
and subject to the final paragraph of Section 3.7, no payment or adjustment
shall be made upon any conversion on account of any interest accrued on the
Securities (or any part thereof) surrendered for conversion or on account of any
dividends on the Common Stock of the Company issued upon such conversion.

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

                                                                            -69-

<PAGE>

Section 14.3 No Fractional Shares.

     No fractional share of Common Stock of the Company shall be issued upon
conversions of Securities of any series. If more than one Security shall be
surrendered for conversion at one time by the same Holder, the number of full
shares which shall be issuable upon conversion shall be computed on the basis of
the aggregate principal amount of the Securities (or specified portions thereof
to the extent permitted hereby) so surrendered. If, except for the provisions of
this Section 14.3, any Holder of a Security or Securities would be entitled to a
fractional share of Common Stock of the Company upon the conversion of such
Security or Securities, or specified portions thereof, the Company shall pay to
such Holder an amount in cash equal to the current market value of such
fractional share computed, (i) if such Common Stock is listed or admitted to
unlisted trading privileges on a national securities exchange or market, on the
basis of the last reported sale price regular way on such exchange or market on
the last trading day prior to the date of conversion upon which such a sale
shall have been effected, or (ii) if such Common Stock is not at the time so
listed or admitted to unlisted trading privileges on a national securities
exchange or market, on the basis of the average of the bid and asked prices of
such Common Stock in the over-the-counter market, on the last trading day prior
to the date of conversion, as reported by the National Quotation Bureau,
Incorporated or similar organization if the National Quotation Bureau,
Incorporated is no longer reporting such information, or if not so available,
the fair market price as determined by the Board of Directors. For purposes of
this Section, "trading day" shall mean each Monday, Tuesday, Wednesday, Thursday
and Friday other than any day on which the Common Stock is not traded on the
Nasdaq National Market, or if the Common Stock is not traded on the Nasdaq
National Market, on the principal exchange or market on which the Common Stock
is traded or quoted.

Section 14.4 Adjustment of Conversion Price.

     The conversion price of Securities of any series that is convertible into
Common Stock of the Company shall be adjusted for any stock dividends, stock
splits, reclassifications, combinations or similar transactions in accordance
with the terms of the supplemental indenture or Board Resolutions setting forth
the terms of the Securities of such series.

     Whenever the conversion price is adjusted, the Company shall compute the
adjusted conversion price in accordance with terms of the applicable Board
Resolution or supplemental indenture and shall prepare an Officers' Certificate
setting forth the adjusted conversion price and showing in reasonable detail the
facts upon which such adjustment is based, and such certificate shall forthwith
be filed at each office or agency maintained for the purpose of conversion of
Securities pursuant to Section 10.2 and, if different, with the Trustee. The
Company shall forthwith cause a notice setting forth the adjusted conversion
price to be mailed, first class postage prepaid, to each Holder of Securities of
such series at its address appearing on the Security Register and to any
conversion agent other than the Trustee.

                                                                            -70-

<PAGE>

Section 14.5 Notice of Certain Corporate Actions.

     In case:

           (1) the Company shall declare a dividend (or any other distribution)
     on its Common Stock payable otherwise than in cash out of its retained
     earnings (other than a dividend for which approval of any shareholders of
     the Company is required) that would require an adjustment pursuant to
     Section 14.4; or

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

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

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

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

Section 14.6 Reservation of Shares of Common Stock.

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

                                                                            -71-

<PAGE>

Section 14.7 Payment of Certain Taxes upon Conversion.

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

Section 14.8 Nonassessability.

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

Section 14.9 Provision in Case of Consolidation, Merger or Sale of Assets.

     In case of any consolidation or merger of the Company with or into any
other Person, any merger of another Person with or into the Company (other than
a merger which does not result in any reclassification, conversion, exchange or
cancellation of outstanding shares of Common Stock of the Company) or any
conveyance, sale, transfer or lease of all or substantially all of the assets of
the Company, the Person formed by such consolidation or resulting from such
merger or which acquires such assets, as the case may be, shall execute and
deliver to the Trustee a supplemental indenture providing that the Holder of
each Security of a series then Outstanding that is convertible into Common Stock
of the Company shall have the right thereafter (which right shall be the
exclusive conversion right thereafter available to said Holder), during the
period such Security shall be convertible, to convert such Security only into
the kind and amount of securities, cash and other property receivable upon such
consolidation, merger, conveyance, sale, transfer or lease by a holder of the
number of shares of Common Stock of the Company into which such Security might
have been converted immediately prior to such consolidation, merger, conveyance,
sale, transfer or lease, assuming such holder of Common Stock of the Company (i)
is not a Person with which the Company consolidated or merged with or into or
which merged into or with the Company or to which such conveyance, sale,
transfer or lease was made, as the case may be (a "Constituent Person"), or an
Affiliate of a Constituent Person and (ii) failed to exercise his rights of
election, if any, as to the kind or amount of securities, cash and other
property receivable upon such consolidation, merger, conveyance, sale, transfer
or lease (provided that if the kind or amount of securities, cash and other
property receivable upon such consolidation, merger, conveyance, sale, transfer,
or lease is not the same for each share of Common Stock of the Company held
immediately prior to such consolidation, merger, conveyance, sale, transfer or
lease by others than a Constituent Person or an Affiliate thereof and in respect
of which such rights of election shall not have been exercised ("Non-electing
Share"), then for the purpose of this Section 14.9 the kind and amount of
securities, cash and other property receivable upon such consolidation, merger,
conveyance, sale, transfer or lease by the holders of each Non-electing Share
shall be deemed to be the kind and

                                                                            -72-

<PAGE>

amount so receivable per share by a plurality of the Non-electing Shares). Such
supplemental indenture shall provide for adjustments which, for events
subsequent to the effective date of such supplemental indenture, shall be as
nearly equivalent as may be practicable to the adjustments provided for in this
Article or in accordance with the terms of the supplemental indenture or Board
Resolutions setting forth the terms of such adjustments. The above provisions of
this Section 14.9 shall similarly apply to successive consolidations, mergers,
conveyances, sales, transfers or leases. Notice of the execution of such a
supplemental indenture shall be given by the Company to the Holder of each
Security of a series that is convertible into Common Stock of the Company as
provided in Section 1.6 promptly upon such execution.

     Neither the Trustee nor any conversion agent, if any, shall be under any
responsibility to determine the correctness of any provisions contained in any
such supplemental indenture relating either to the kind or amount of shares of
stock or other securities or property or cash receivable by Holders of
Securities of a series convertible into Common Stock of the Company upon the
conversion of their Securities after any such consolidation, merger, conveyance,
transfer, sale or lease or to any such adjustment, but may accept as conclusive
evidence of the correctness of any such provisions, and shall be protected in
relying upon, an Opinion of Counsel with respect thereto, which the Company
shall cause to be furnished to the Trustee upon request.

Section 14.10 Duties of Trustee Regarding Conversion.

     Neither the Trustee nor any conversion agent shall at any time be under any
duty or responsibility to any Holder of Securities of any series that is
convertible into Common Stock of the Company to determine whether any facts
exist which may require any adjustment of the conversion price, or with respect
to the nature or extent of any such adjustment when made, or with respect to the
method employed, whether herein or in any supplemental indenture, any
resolutions of the Board of Directors or written instrument executed by one or
more officers of the Company provided to be employed in making the same. Neither
the Trustee nor any conversion agent shall be accountable with respect to the
validity or value (or the kind or amount) of any shares of Common Stock of the
Company, or of any securities or property, which may at any time be issued or
delivered upon the conversion of any Securities and neither the Trustee nor any
conversion agent makes any representation with respect thereto. Subject to the
provisions of Section 6.1, neither the Trustee nor any conversion agent shall be
responsible for any failure of the Company to issue, transfer or deliver any
shares of its Common Stock or stock certificates or other securities or property
upon the surrender of any Security for the purpose of conversion or to comply
with any of the covenants of the Company contained in this Article 14 or in the
applicable supplemental indenture, resolutions of the Board of Directors or
written instrument executed by one or more duly authorized officers of the
Company.

Section 14.11 Repayment of Certain Funds upon Conversion.

     Any funds which at any time shall have been deposited by the Company or on
its behalf with the Trustee or any other paying agent for the purpose of paying
the principal of, and premium, if any, and interest, if any, on any of the
Securities (including, but not limited to, funds deposited for the sinking fund
referred to in Article 12 hereof and funds deposited pursuant to Article 13
hereof)

                                                                            -73-

<PAGE>

and which shall not be required for such purposes because of the conversion of
such Securities as provided in this Article 14 shall after such conversion be
repaid to the Company by the Trustee upon the Company's written request.

                                   ARTICLE 15

                           SUBORDINATION OF SECURITIES

Section 15.1 Agreement of Subordination.

     Except as otherwise provided in a supplemental indenture or pursuant to
Section 3.1, the Company covenants and agrees, and each Holder of Securities
issued hereunder by its acceptance thereof likewise covenants and agrees, that
all Securities shall be issued subject to the provisions of this Article 15; and
each Person holding any Security, whether upon original issue or upon transfer,
assignment or exchange thereof, accepts and agrees to be bound by such
provisions.

     The payment of the principal of, premium, if any, and interest on all
Securities (including, but not limited to, the redemption price with respect to
the Securities called for redemption in accordance with Article 11 as provided
in the Indenture) issued hereunder shall, to the extent and in the manner
hereinafter set forth, be subordinated and subject in right of payment to the
prior payment in full of all Senior Debt, whether outstanding at the date of
this Indenture or thereafter incurred.

     No provision of this Article 15 shall prevent the occurrence of any default
or Event of Default hereunder.

Section 15.2 Payments to Holders.

     No payment shall be made with respect to the principal of, or premium, if
any, or interest on the Securities (including, but not limited to, the
redemption price with respect to the Securities to be called for redemption in
accordance with Article 11 as provided in the Indenture), except payments and
distributions made by the Trustee as permitted by the first or second paragraph
of Section 15.5, if:

                    (i)  a default in the payment of principal, premium, if any,
               interest, rent or other obligations due on any Senior Debt occurs
               and is continuing (or, in the case of Senior Debt for which there
               is a period of grace, in the event of such a default that
               continues beyond the period of grace, if any, specified in the
               instrument or lease evidencing such Senior Debt) (a "Payment
               Default"), unless and until such default shall have been cured or
               waived or shall have ceased to exist; or

                    (ii) a default, other than a Payment Default, on any
               Designated Senior Debt occurs and is continuing that then permits
               holders of such Designated Senior Debt to accelerate its maturity
               and the Trustee receives a

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               notice of the default (a "Payment Blockage Notice") from a holder
               of Designated Senior Debt, a Representative of Designated Senior
               Debt or the Company (a "Non-Payment Default").

     If the Trustee receives any Payment Blockage Notice pursuant to clause (ii)
above, no subsequent Payment Blockage Notice shall be effective for purposes of
this Section unless and until at least 365 days shall have elapsed since the
initial effectiveness of the immediately prior Payment Blockage Notice. No
Non-Payment Default that existed or was continuing on the date of delivery of
any Payment Blockage Notice to the Trustee shall be, or be made, the basis for a
subsequent Payment Blockage Notice.

     The Company may and shall resume payments on and distributions in respect
of the Securities upon the earlier of:

           (1) in the case of a Payment Default, the date upon which the Payment
     Default is cured or waived or ceases to exist, or

           (2) in the case of a Non-Payment Default, the earlier of (a) the date
     upon which such Non-Payment Default is cured, waived or ceases to exist or
     (b) 179 days after the date on which the applicable Payment Blockage Notice
     is received by the Trustee,

unless this Article 15 otherwise prohibits the payment or distribution at such
time.

     Upon any payment, or distribution of the assets of the Company of any kind
or character, (whether in cash, property or securities, to creditors upon any
dissolution or winding-up or liquidation or reorganization of the Company,
whether voluntary or involuntary or in bankruptcy, insolvency, reorganization,
liquidation, receivership or other proceedings, or upon an assignment for the
benefit of creditors or any marshalling of the assets and liabilities of the
Company, or otherwise, all amounts due or to become due upon all Senior Debt
shall first be paid in full in cash or other payment satisfactory to the holders
of such Senior Debt, or payment thereof in accordance with its terms provided
for in cash or other payment satisfactory to the holders of such Senior Debt,
before any payment is made on account of the principal of, premium, if any, or
interest on the Securities (except payments made pursuant to Article 4 from
monies deposited with the Trustee pursuant thereto prior to commencement of
proceedings for such dissolution, winding-up, liquidation, reorganization,
assignment for the benefit of creditors or the marshalling of assets and
liabilities of the Company); and upon any such dissolution, winding-up,
liquidation or reorganization of the Company, assignment for the benefit of
creditors or the marshalling of assets and liabilities of the Company or
bankruptcy, insolvency, receivership or other proceeding, any payment by the
Company, or distribution of assets of the Company of any kind or character,
whether in cash, property or securities, to which the Holders of the Securities
or the Trustee would be entitled, except for the provision of this Article 15,
shall (except as aforesaid) be paid by the Company or by any receiver, trustee
in bankruptcy, liquidating trustee, agent or other Person making such payment or
distribution, or by the Holders of the Securities or by the Trustee under this
Indenture if received by them or it, directly to the holders of Senior Debt (pro
rata to such holders on the basis of the respective amounts of Senior Debt held
by such holders, or as otherwise required by law or a court order) or their
Representative or Representatives, or to the trustee or trustees under any
indenture pursuant to which any instruments evidencing any Senior Debt may have
been issued, as their respective interests may appear, to the

                                                                            -75-

<PAGE>

extent necessary to pay all Senior Debt in full, in cash or other payment
satisfactory to the holders of such Senior Debt, after giving effect to any
concurrent payment or distribution to or for the holders of Senior Debt, before
any payment or distribution or provision therefor is made to the Holders of the
Securities or to the Trustee.

     For purposes of this Article 15, the words, "cash, property or securities"
shall not be deemed to include shares of stock of the Company as reorganized or
readjusted, or securities of the Company or any other corporation provided for
by a plan of reorganization or readjustment, the payment of which is
subordinated at least to the extent provided in this Article 15 with respect to
the Securities to the payment of all Senior Debt which may at the time be
outstanding; provided that (i) the Senior Debt is assumed by the new
corporation, if any, resulting from any reorganization or readjustment, and (ii)
the rights of the holders of Senior Debt (other than leases which are not
assumed by the Company or the new corporation, as the case may be) are not,
without the consent of such holders, altered by such reorganization or
readjustment. The consolidation of the Company with, or the merger of the
Company into, another corporation or the liquidation or dissolution of the
Company following the conveyance or transfer of its property as an entirety, or
substantially as an entirety, to another corporation upon the terms and
conditions provided for in Article 8 shall not be deemed a dissolution,
winding-up, liquidation or reorganization for the purposes of this Section 15.2
if such other corporation shall, as a part of such consolidation, merger,
conveyance or transfer, comply with the conditions stated in Article 8.

     In the event of the acceleration of the Securities because of an Event of
Default, no payment or distribution shall be made to the Trustee or any Holder
of Securities in respect of the principal of, premium, if any, or interest on
the Securities (including, but not limited to, the redemption price with respect
to the Securities called for redemption in accordance with Article 11 as
provided in the Indenture), except payments and distributions made by the
Trustee as permitted by the first or second paragraph of Section 15.5, until all
Senior Debt has been paid in full in cash or other payment satisfactory to the
holders of Senior Debt or such acceleration is rescinded in accordance with the
terms of this Indenture. If payment of the Securities is accelerated because of
an Event of Default, the Company shall promptly notify holders of Senior Debt of
the acceleration.

     In the event that, notwithstanding the foregoing provisions, any payment or
distribution of assets of the Company of any kind or character, whether in cash,
property or securities (including, without limitation, by way of setoff or
otherwise), prohibited by the foregoing, shall be received by the Trustee or the
Holders of the Securities before all Senior Debt is paid in full in cash or
other payment satisfactory to the holders of such Senior Debt, or provision is
made for such payment thereof in accordance with its terms in cash or other
payment satisfactory to the holders of such Senior Debt, such payment or
distribution shall be held in trust for the benefit of and shall be paid over or
delivered to the holders of Senior Debt or their Representative or
Representatives, or to the trustee or trustees under any indenture pursuant to
which any instruments evidencing any Senior Debt may have been issued, as their
respective interests may appear, as calculated by the Company, for application
to the payment of all Senior Debt remaining unpaid to the extent necessary to
pay all Senior Debt in full in cash or other payment satisfactory to the holders
of such Senior Debt, after giving effect to any concurrent payment or
distribution to or for the holders of such Senior Debt.

                                                                            -76-

<PAGE>

     Nothing in this Section 15.2 shall apply to claims of, or payments to, the
Trustee under or pursuant to Section 6.7. This Section 15.2 shall be subject to
the further provisions of Section 15.5.

Section 15.3 Subrogation of Securities.

     Subject to the payment in full of all Senior Debt, the rights of the
Holders of the Securities shall be subrogated to the extent of the payments or
distributions made to the holders of such Senior Debt pursuant to the provisions
of this Article 15 (equally and ratably with the holders of all indebtedness of
the Company which by its express terms is subordinated to other indebtedness of
the Company to substantially the same extent as the Securities are subordinated
and is entitled to like rights of subrogation) to the rights of the holders of
Senior Debt to receive payments or distributions of cash, property or securities
of the Company applicable to the Senior Debt until the principal, premium, if
any, and interest on the Securities shall be paid in full; and, for the purposes
of such subrogation, no payments or distributions to the holders of the Senior
Debt of any cash, property or securities to which the Holders of the Securities
or the Trustee would be entitled except for the provisions of this Article 15,
and no payment over pursuant to the provisions of this Article 15, to or for the
benefit of the holders of Senior Debt by Holders of the Securities or the
Trustee, shall, as between the Company, its creditors other than holders of
Senior Debt, and the Holders of the Securities, be deemed to be a payment by the
Company to or on account of the Senior Debt; and no payments or distributions of
cash, property or securities to or for the benefit of the Holders of the
Securities pursuant to the subrogation provisions of this Article 15, which
would otherwise have been paid to the holders of Senior Debt shall be deemed to
be a payment by the Company to or for the account of the Securities. It is
understood that the provisions of this Article 15 are and are intended solely
for the purposes of defining the relative rights of the Holders of the
Securities, on the one hand, and the holders of the Senior Debt, on the other
hand.

     Nothing contained in this Article 15 or elsewhere in this Indenture or in
the Securities is intended to or shall impair, as among the Company, its
creditors other than the holders of Senior Debt, and the Holders of the
Securities, the obligation of the Company, which is absolute and unconditional,
to pay to the Holders of the Securities the principal of (and premium, if any)
and interest on the Securities as and when the same shall become due and payable
in accordance with their terms, or is intended to or shall affect the relative
rights of the Holders of the Securities and creditors of the Company other than
the holders of the Senior Debt, nor shall anything herein or therein prevent the
Trustee or the Holder of any Security from exercising all remedies otherwise
permitted by applicable law upon default under this Indenture, subject to the
rights, if any, under this Article 15 of the holders of Senior Debt in respect
of cash, property or securities of the Company received upon the exercise of any
such remedy.

     Upon any payment or distribution of assets of the Company referred to in
this Article 15, the Trustee, subject to the provisions of Section 6.1, and the
Holders of the Securities shall be entitled to rely upon any order or decree
made by any court of competent jurisdiction in which such bankruptcy,
dissolution, winding-up, liquidation or reorganization proceedings are pending,
or a certificate of the receiver, trustee in bankruptcy, liquidating trustee,
agent or other person making such payment or distribution, delivered to the
Trustee or to the Holders of the Securities, for the

                                                                            -77-

<PAGE>

purpose of ascertaining the persons entitled to participate in such
distribution, the holders of the Senior Debt and other indebtedness of the
Company, the amount thereof or payable thereon and all other facts pertinent
thereto or to this Article 15.

Section 15.4 Authorization to Effect Subordination.

     Each Holder of a Security by the holder's acceptance thereof authorizes and
directs the Trustee on the holder's behalf to take such action as may be
necessary or appropriate to effectuate the subordination as provided in this
Article 15 and appoints the Trustee to act as the holder's attorney-in-fact for
any and all such purposes. If the Trustee does not file a proper proof of claim
or proof of debt in the form required in any proceeding referred to in Section
5.4 hereof at least 30 days before the expiration of the time to file such
claim, the holders of any Senior Debt or their representatives are hereby
authorized to file an appropriate claim for and on behalf of the Holders of the
Securities.

Section 15.5 Notice to Trustee.

     The Company shall give prompt written notice in the form of an Officers'
Certificate to a Responsible Officer of the Trustee and to any Paying Agent of
any fact known to the Company which would prohibit the making of any payment of
monies to or by the Trustee or any Paying Agent in respect of the Securities
pursuant to the provisions of this Article 15. Notwithstanding the provisions of
this Article 15 or any other provision of this Indenture, the Trustee shall not
be charged with knowledge of the existence of any facts which would prohibit the
making of any payment of monies to or by the Trustee in respect of the
Securities pursuant to the provisions of this Article 15, unless and until a
Responsible Officer of the Trustee shall have received written notice thereof at
the Corporate Trust Office from the Company (in the form of an Officers'
Certificate) or a Representative or a holder or holders of Senior Debt or from
any trustee therefor; and before the receipt of any such written notice, the
Trustee, subject to the provisions of Section 6.1, shall be entitled in all
respects to assume that no such facts exist; provided that if on a date not
                                             --------
fewer than two Business Days prior to the date upon which by the terms hereof
any such monies may become payable for any purpose (including, without
limitation, the payment of the principal of, or premium, if any, or interest on
any Security) the Trustee shall not have received, with respect to such monies,
the notice provided for in this Section 15.5, then, anything herein contained to
the contrary notwithstanding, the Trustee shall have full power and authority to
receive such monies and to apply the same to the purpose for which they were
received, and shall not be affected by any notice to the contrary which may be
received by it on or after such prior date.

     Notwithstanding anything in this Article 15 to the contrary, nothing shall
prevent any payment by the Trustee to the Holders of monies deposited with it
pursuant to Section 4.1, and any such payment shall not be subject to the
provisions of Section 15.1 or 15.2.

     The Trustee, subject to the provisions of Section 6.1, shall be entitled to
rely on the delivery to it of a written notice by a Representative or a person
representing himself to be a holder of Senior Debt (or a trustee on behalf of
such holder) to establish that such notice has been given by a Representative or
a holder of Senior Debt or a trustee on behalf of any such holder or holders.
The

                                                                            -78-

<PAGE>

Trustee shall not be required to make any payment or distribution to or on
behalf of a holder of Senior Debt pursuant to this Article 15 unless it has
received satisfactory evidence as to the amount of Senior Debt held by such
person, the extent to which such person is entitled to participate in such
payment or distribution and any other facts pertinent to the rights of such
person under this Article 15.

Section 15.6 Trustee's Relation to Senior Debt.

     The Trustee in its individual capacity shall be entitled to all the rights
set forth in this Article 15 in respect of any Senior Debt at any time held by
it, to the same extent as any other holder of Senior Debt, and nothing in this
Indenture shall deprive the Trustee of any of its rights as such holder.

     With respect to the holders of Senior Debt, the Trustee undertakes to
perform or to observe only such of its covenants and obligations as are
specifically set forth in this Article 15, and no implied covenants or
obligations with respect to the holders of Senior Debt shall be read into this
Indenture against the Trustee. The Trustee shall not be deemed to owe any
fiduciary duty to the holders of Senior Debt and, subject to the provisions of
Section 6.1, the Trustee shall not be liable to any holder of Senior Debt (i)
for any failure to make any payments or distributions to such holders or (ii) if
it shall pay over or deliver to Holders of Securities, the Company or any other
Person money or assets to which any holder of Senior Debt shall be entitled by
virtue of this Article 15 or otherwise.

Section 15.7 No Impairment of Subordination.

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

Section 15.8 Certain Conversions/Exchanges Deemed Payment.

     For the purposes of this Article 15 only, (1) the issuance and delivery of
junior securities upon conversion or exchange of Securities in accordance with
Article 14 or otherwise (except upon conversion of the Securities in accordance
with their terms) shall not be deemed to constitute a payment or distribution on
account of the principal of (or premium, if any) or interest on Securities or on
account of the purchase or other acquisition of Securities, and (2) the payment,
issuance or delivery of cash (except in satisfaction of fractional shares
pursuant to Section 14.3), property or securities (other than junior securities)
upon conversion or exchange of a Security shall be deemed to constitute payment
on account of the principal of such Security. For the purposes of this Section
15.8, the term "junior securities" means (a) shares of any stock of any class of
the Company, or (b) securities of the Company which are subordinated in right of
payment to all Senior Debt which may be outstanding at the time of issuance or
delivery of such securities to substantially the same extent as, or to a greater
extent than, the Securities are so subordinated as provided in this Article.
Nothing contained in this Article 15 or elsewhere in this Indenture or in the
Securities is intended to or shall impair, as among

                                                                            -79-

<PAGE>

the Company, its creditors other than holders of Senior Debt and the Holders of
Securities, the right, which is absolute and unconditional, of the Holder of any
Security to convert such Security in accordance with Article 14.

Section 15.9  Article Applicable to Paying Agents.

     If at any time any Paying Agent other than the Trustee shall have been
appointed by the Company and be then acting hereunder, the term "Trustee" as
used in this Article shall (unless the context otherwise requires) be construed
as extending to and including such Paying Agent within its meaning as fully for
all intents and purposes as if such Paying Agent were named in this Article in
addition to or in place of the Trustee; provided, however, that the first
                                        --------  -------
paragraph of Section 15.5 shall not apply to the Company or any Affiliate of the
Company if the Company or such Affiliate acts as Paying Agent.

     The Trustee shall not be responsible for the actions or inactions of any
other Paying Agents (including the Company if acting as its own Paying Agent)
and shall have no control of any funds held by such other Paying Agents.

Section 15.10 Senior Debt Entitled to Rely.

     The holders of Senior Debt (including, without limitation, Designated
Senior Debt) shall have the right to rely upon this Article 15, and no amendment
or modification of the provisions contained herein shall diminish the rights of
such holders unless such holders shall have agreed in writing thereto.

Section 15.11 Reliance on Judicial Order or Certificate of Liquidating Agent.

     Upon any payment or distribution of assets of the Company referred to in
this Article, the Trustee and the Holders shall be entitled to rely upon any
order or decree entered by any court of competent jurisdiction in which such
dissolution, winding up, liquidation, reorganization, assignment for the benefit
of creditors or marshalling of assets and liabilities of the Company or
bankruptcy, insolvency, receivership or other like proceeding is pending, or a
certificate of the trustee in bankruptcy, liquidating trustee, custodian,
receiver, assignee for the benefit of creditors, agent or other person making
such payment or distribution, delivered to the Trustee or to the Holders, for
the purpose of ascertaining the persons entitled to participate in such payment
or distribution, the holders of Senior Debt and other indebtedness of the
Company, the amount thereof or payable thereon, the amount or amounts paid or
distributed thereon and all other facts pertinent thereto or to this Article.

Section 15.12 Trust Monies Not Subordinated.

     Notwithstanding anything contained herein to the contrary, payments from
money, U.S. Government Obligations and/or Foreign Government Obligations held in
trust under Article 4 or Article 13 by the Trustee for the payment of the
principal of, premium, if any, and interest on the Securities shall not be
subordinated to the prior payment in full of any Senior Debt of the Company or
subject to the restrictions set forth in this Article 15, and none of the
Holders shall be obligated to pay over any such amount to the Company or any
holder of Senior Debt of the Company or any other creditor of the Company.

            [The remainder of this page is intentionally left blank]

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<PAGE>

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

                                    NPS PHARMACEUTICALS, INC.

                                    By: ________________________________________

                                    Title: _____________________________________

                                    U.S. BANK NATIONAL ASSOCIATION, as Trustee

                                    By:  _______________________________________

                                    Title: _____________________________________

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