Document:

<PAGE>

                                                                   Exhibit 4.3

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

                              SONUS NETWORKS, INC.

                                     ISSUER

                                       TO

                           [-------------------------]

                                     TRUSTEE

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

                                    INDENTURE

                        Dated as of              ,
                                    -------------  -----

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

                          SUBORDINATED DEBT SECURITIES

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

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                                TABLE OF CONTENTS

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

  SECTION 1.1  Definitions ..................................................1
  SECTION 1.2  Compliance Certificates And Opinions.........................11
  SECTION 1.3  Form of Documents Delivered to the Trustee...................11
  SECTION 1.4  Acts of Holders .............................................12
  SECTION 1.5  Notices, Etc. to the Trustee and Company.....................14
  SECTION 1.6  Notice to Holders; Waiver....................................14
  SECTION 1.7  Effect of Headings and Table of Contents.....................15
  SECTION 1.8  Successors and Assigns.......................................15
  SECTION 1.9  Separability Clause..........................................15
  SECTION 1.10 Benefits of Indenture........................................15
  SECTION 1.11 Governing Law................................................15
  SECTION 1.12 Legal Holidays...............................................16
  SECTION 1.13 Conflict With Trust Indenture Act............................16

ARTICLE II SECURITY FORMS...................................................17

  SECTION 2.1  Form Generally...............................................17
  SECTION 2.2  Form of Security.............................................17
  SECTION 2.3  Form of Certificate of Authentication........................28
  SECTION 2.4  Form of Conversion Notice....................................29
  SECTION 2.5  Form of Assignment...........................................30

ARTICLE III THE SECURITIES..................................................31

  SECTION 3.1  Title and Terms..............................................31
  SECTION 3.2  Denominations................................................32
  SECTION 3.3  Execution, Authentication, Delivery and Dating...............32
  SECTION 3.4  Global Securities; Non-global Securities; Book-entry
               Provisions...................................................32
  SECTION 3.5  Registration; Registration of Transfer and Exchange;
               Restrictions on Transfer.....................................34
  SECTION 3.6  Mutilated, Destroyed, Lost or Stolen Securities..............35
  SECTION 3.7  Payment of Interest; Interest Rights Preserved...............36
  SECTION 3.8  Persons Deemed Owners........................................37
  SECTION 3.9  Cancellation.................................................38
  SECTION 3.10 Computation of Interest......................................38
  SECTION 3.11 CUSIP Numbers................................................38
</TABLE>

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<TABLE>
<S>                                                                         <C>
ARTICLE IV SATISFACTION AND DISCHARGE.......................................38

  SECTION 4.1  Satisfaction and Discharge of Indenture......................38
  SECTION 4.2  Application of Trust Money...................................39

ARTICLE V REMEDIES..........................................................40

  SECTION 5.1  Events of Default............................................40
  SECTION 5.2  Acceleration of Maturity; Rescission and Annulment...........42
  SECTION 5.3  Collection of Indebtedness and Suits for Enforcement
                 by Trustee.................................................43
  SECTION 5.4  Trustee May File Proofs of Claim.............................43
  SECTION 5.5  Trustee May Enforce Claims Without Possession
                 of Securities..............................................44
  SECTION 5.6  Application of Money Collected...............................44
  SECTION 5.7  Limitation on Suits..........................................45
  SECTION 5.8  Unconditional Right of Holders to Receive Principal,
                 Premium and Interest and to Convert........................46
  SECTION 5.9  Restoration of Rights and Remedies...........................46
  SECTION 5.10 Rights and Remedies Cumulative...............................46
  SECTION 5.11 Delay or Omission Not Waiver.................................46
  SECTION 5.12 Control by Holders...........................................47
  SECTION 5.13 Waiver of Past Defaults......................................47
  SECTION 5.14 Undertaking for Costs........................................47
  SECTION 5.15 Waiver of Stay, Usury or Extension Laws......................48

ARTICLE VI THE TRUSTEE......................................................48

  SECTION 6.1  Certain Duties and Responsibilities..........................48
  SECTION 6.2  Notice of Defaults...........................................49
  SECTION 6.3  Certain Rights of Trustee....................................50
  SECTION 6.4  Not Responsible for Recitals or Issuance of Securities.......51
  SECTION 6.5  May Hold Securities, Act as Trustee under Other Indentures...51
  SECTION 6.6  Money Held in Trust..........................................51
  SECTION 6.7  Compensation and Reimbursement...............................51
  SECTION 6.8  Corporate Trustee Required; Eligibility......................52
  SECTION 6.9  Resignation and Removal; Appointment of Successor............52
  SECTION 6.10 Acceptance of Appointment by Successor.......................54
  SECTION 6.11 Merger, Conversion, Consolidation or Succession
                  to Business...............................................54
  SECTION 6.12  Authenticating Agents.......................................54
  SECTION 6.13  Disqualification; Conflicting Interests.....................56
  SECTION 6.14  Preferential Collection of Claims Against Company...........56
</TABLE>
                                      -ii-

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<TABLE>
<S>                                                                         <C>
ARTICLE VII CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE............56

  SECTION 7.1  Company May Consolidate, Etc., Only on
    Certain Terms...........................................................56
  SECTION 7.2  Successor Substituted........................................57

ARTICLE VIII SUPPLEMENTAL INDENTURES........................................57

  SECTION 8.1  Supplemental Indentures Without Consent of Holders...........57
  SECTION 8.2  Supplemental Indentures with Consent of Holders..............58
  SECTION 8.3  Execution of Supplemental Indentures.........................59
  SECTION 8.4  Effect of Supplemental Indentures............................60
  SECTION 8.5  Reference in Securities to Supplemental Indentures...........60
  SECTION 8.6  Notice of Supplemental Indentures............................60

ARTICLE IX MEETINGS OF HOLDERS..............................................60

  SECTION 9.1  Purposes for Which Meetings May Be Called....................60
  SECTION 9.2  Call, Notice and Place of Meetings...........................61
  SECTION 9.3  Persons Entitled to Vote at Meetings.........................61
  SECTION 9.4  Quorum; Action...............................................61
  SECTION 9.5  Determination of Voting Rights; Conduct and
                 Adjournment of Meetings....................................62
  SECTION 9.6  Counting Votes and Recording Action of Meetings..............63

ARTICLE X COVENANTS.........................................................63

  SECTION 10.1  Payment of Principal, Premium and Interest..................63
  SECTION 10.2  Maintenance of Offices or Agencies..........................64
  SECTION 10.3  Money for Security Payments to Be Held in Trust.............64
  SECTION 10.4  Existence...................................................66
  SECTION 10.5  Payment of Taxes and Other Claims...........................66
  SECTION 10.6  Registration and Listing....................................66
  SECTION 10.7  Statement by Officers as to Default.........................67
  SECTION 10.8  Waiver of Certain Covenants.................................67

ARTICLE XI REDEMPTION OF SECURITIES.........................................67

  SECTION 11.1  Right of Redemption.........................................67
  SECTION 11.2  Applicability of Article....................................68
  SECTION 11.3  Election to Redeem; Notice to Trustee.......................68
  SECTION 11.4  Selection by Trustee of Securities to Be Redeemed...........68
  SECTION 11.5  Notice of Redemption........................................69
  SECTION 11.6  Deposit of Redemption Price.................................69
  SECTION 11.7  Securities Payable on Redemption Date.......................70
  SECTION 11.8  Conversion Arrangement on Call for Redemption...............71
</TABLE>

                                     -iii-

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<TABLE>
<S>                                                                         <C>
ARTICLE XII CONVERSION OF SECURITIES........................................72

  SECTION 12.1  Conversion Privilege and Conversion Rate....................72
  SECTION 12.2  Exercise of Conversion Privilege............................72
  SECTION 12.3  Fractions of Shares.........................................73
  SECTION 12.4  Adjustment of Conversion Rate...............................74
  SECTION 12.5  Notice of Adjustments of Conversion Rate....................78
  SECTION 12.6  Notice of Certain Corporate Action..........................79
  SECTION 12.7  Company to Reserve Common Stock.............................80
  SECTION 12.8  Taxes on Conversions........................................80
  SECTION 12.9  Covenant as to Common Stock.................................80
  SECTION 12.10 Cancellation of Converted Securities........................80
  SECTION 12.11 Provision in Case of Consolidation, Merger or
                   Sale of Assets...........................................80
  SECTION 12.12 Rights Issued in respect of Common Stock....................81
  SECTION 12.13 Responsibility of Trustee for Conversion Provisions.........82

ARTICLE XIII SUBORDINATION OF SECURITIES....................................83

  SECTION 13.1  Securities Subordinate to Senior Debt.......................83
  SECTION 13.2  No Payment in Certain Circumstances, Payment over
                  of Proceeds upon Dissolution, Etc.........................83
  SECTION 13.3  Prior Payment to Senior Debt upon Acceleration
                  of Securities.............................................85
  SECTION 13.4  Payment Permitted If No Default.............................86
  SECTION 13.5  Subrogation to Rights of Holders of Senior Debt.............86
  SECTION 13.6  Provisions Solely to Define Relative Rights.................86
  SECTION 13.7  Trustee to Effectuate Subordination.........................87
  SECTION 13.8  No Waiver of Subordination Provisions.......................87
  SECTION 13.9  Notice to Trustee...........................................87
  SECTION 13.10 Reliance on Judicial Order or Certificate of
                   Liquidating Agent........................................88
  SECTION 13.11 Trustee Not Fiduciary for Holders of Senior Debt............88
  SECTION 13.12 Reliance by Holders of Senior Debt on Subordination
                   Provisions...............................................89
  SECTION 13.13 Rights of Trustee as Holder of Senior Debt;
                   Preservation of Trustee's Rights.........................89
  SECTION 13.14 Article Applicable to Paying Agents.........................89
  SECTION 13.15 Certain Conversions and Repurchases Deemed Payment..........90

ARTICLE XIV REPURCHASE OF SECURITIES AT THE OPTION OF THE HOLDER
         UPON A CHANGE IN CONTROL...........................................91

  SECTION 14.1  Right to Require Repurchase.................................91
  SECTION 14.2  Conditions to the Company's Election to Pay the
                   Repurchase Price or the Make-Whole Payment in
                   Common Stock.............................................91
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                                      -iv-

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  SECTION 14.3  Notices; Method of Exercising Repurchase Right, Etc.........92
  SECTION 14.4  Certain Definitions.........................................95
  SECTION 14.5  Consolidation, Merger, Etc..................................97

ARTICLE XV HOLDERS LISTS AND REPORTS BY TRUSTEE AND COMPANY;
  NON-RECOURSE..............................................................97

  SECTION 15.1  Company to Furnish Trustee Names and Addresses of
                  Holders...................................................97
  SECTION 15.2  Preservation of Information.................................98
  SECTION 15.3  Reports by Trustee..........................................98
  SECTION 15.4  Reports by Company..........................................98

ARTICLE XVI IMMUNITY OF INCORPORATORS, STOCKHOLDERS, OFFICERS
         AND DIRECTORS......................................................99

  SECTION 16.1  Indenture and Securities Solely Corporate Obligations.......99

                                      -v-

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<TABLE>
<CAPTION>
TRUST INDENTURE ACT SECTION                                                              INDENTURE SECTION

<S>                                                                                      <C>
Section     310    (a)(1)..............................................................  6.8
                   (a)(2)..............................................................  6.8
                   (a)(3)..............................................................  Not Applicable
                   (a)(4)..............................................................  Not Applicable
                   (b).................................................................  6.8, 6.9, 6.13
Section     311    (a).................................................................  6.14
                   (b).................................................................  6.14
Section     312    (a).................................................................  15.1, 15.2(1)
                   (b).................................................................  15.2(2)
                   (c).................................................................  15.2(3)
Section     313    (a).................................................................  15.3(1)
                   (b).................................................................  15.3(1)
                   (c).................................................................  15.3(1)
                   (d).................................................................  15.3(2)
Section     314    (a)(1)..............................................................  15.4
                   (a)(2)..............................................................  15.4
                   (a)(3)..............................................................  15.4
                   (a)(4)..............................................................  10.7
                   (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(1), 6.3
                   (b).................................................................  6.2
                   (c).................................................................  6.1(2)
                   (d).................................................................  6.1(3)
                   (e).................................................................  5.14
Section     316    (a)(last sentence)..................................................  1.1 ("Outstanding")
                   (a)(1)(A)...........................................................  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
</TABLE>

                                      -vi-

<PAGE>

        INDENTURE, dated as of _________________________,____ between SONUS
NETWORKS, INC., a corporation duly organized and existing under the laws of the
State of Delaware, having its principal office at 5 Carlisle Road, Westford,
Massachusetts 01886 (herein called the "Company"), and _____________________, a
________________ corporation, as Trustee hereunder (herein called the
"Trustee").

                             RECITALS OF THE COMPANY

        The Company has duly authorized the creation of an issue of its ____%
[Convertible](1) Subordinated Notes due ______,_____ (herein called the
"Securities") of substantially the tenor and amount hereinafter set forth, and
to provide therefor the Company has duly authorized the execution and delivery
of this Indenture.

        All things necessary to make the Securities, when the Securities are
executed by the Company and authenticated and delivered hereunder, the valid
obligations of the Company, and to make this Indenture a valid agreement of the
Company, in accordance with their and its terms, have been done. [Further, all
things necessary to duly authorize the issuance of the Common Stock of the
Company issuable upon the conversion of the Securities, and to duly reserve for
issuance the number of shares of Common Stock issuable upon such conversion,
have been done.](2)

        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, as follows:

                                    ARTICLE I

        DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

        SECTION 1.1 DEFINITIONS.

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

        (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;

----------
        (1) INSERT IF SECURITIES ARE CONVERTIBLE

        (2) INSERT IF SECURITIES ARE CONVERTIBLE

<PAGE>

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

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

        "Agent Member" means any member of, or participant in, the Depositary.

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

         "Authenticating Agent" means any Person authorized pursuant to Section
6.12 to act on behalf of the Trustee to authenticate Securities.

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

         "Board Resolution" means a resolution duly adopted by the Board of
Directors, a copy of which, 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, shall have been
delivered to the Trustee.

        "Business Day", when used with respect to any Place of Payment [or Place
of Conversion, as the case may be,](3) means each Monday, Tuesday, Wednesday,
Thursday and Friday which is not a day on which banking institutions in such
Place of Payment[, Place of Conversion](4) or other place, as the case may be,
are authorized or obligated by law or executive

----------

        (3) INSERT IF SECURITIES ARE CONVERTIBLE

        (4) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -2-
<PAGE>

order to close; provided, however, that a day on which banking institutions in
New York, New York are authorized or obligated by law or executive order to
close shall not be a Business Day for purposes of Section 13.9.

         "Change in Control" has the meaning specified in Section 14.4(2).

         "Closing Price Per Share" means, with respect to the Common Stock, for
any day, (i) the last reported bid price regular way on the Nasdaq National
Market or, (ii) if the Common Stock is not quoted on the Nasdaq National Market,
the last reported sale price regular way per share or, in case no such reported
sale takes place on such day, the average of the reported closing bid and asked
prices regular way, in either case, on the principal national securities
exchange on which the Common Stock is listed or admitted to trading, or (iii) if
the Common Stock is not quoted on the Nasdaq National Market or listed or
admitted to trading on any national securities exchange, the average of the
closing bid prices in the over-the-counter market as furnished by any New York
Stock Exchange member firm selected from time to time by the Company for that
purpose.

         "Code" has the meaning specified in Section 2.l.

         "Commission" means the United States Securities and Exchange
Commission, as 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" means the Common Stock, par value $0.001 per share, of
the Company authorized at the date of this instrument as originally executed.
[Subject to the provisions of Section 12.11,](5) shares issuable on
[conversion](6) or repurchase of Securities shall include only shares of Common
Stock or shares of any class or classes of common stock resulting from any
reclassification or reclassifications thereof[; provided, however, that if at
any time there shall be more than one such resulting class, the shares so
issuable on conversion of Securities shall include shares of all such classes,
and 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.](7)

        "common stock" includes any stock of any class of capital stock which
has no preference in respect of dividends or of amounts payable in the event of
any voluntary or involuntary

----------

        (5) INSERT IF SECURITIES ARE CONVERTIBLE

        (6) INSERT IF SECURITIES ARE CONVERTIBLE

        (7) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -3-
<PAGE>

liquidation, dissolution or winding up of the issuer thereof and which is not
subject to redemption by the issuer thereof.

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

         "Company Notice" has the meaning specified in Section 14.3.

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

         ["Conversion Agent" means any Person authorized by the Company to
convert Securities in accordance with Article XII. The Company has initially
appointed the Trustee as its Conversion Agent pursuant to Section 10.2 hereof.

         "Constituent Person" has the meaning specified in Section 12.11.]

         ["Conversion Price" has the meaning specified in Section 14.4(3).

         "Conversion Rate" has the meaning specified in Section 12.1.](9)

        "Corporate Trust Office" means the office of the Trustee at which at any
particular time its corporate trust business shall be principally administered
(which at the date of this Indenture is located at _______________, Attention:
_____________________________ .

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

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

         "Depositary" means, with respect to any Securities (including any
Global Securities), a clearing agency that is registered as such under the
Exchange Act and is designated by the Company to act as Depositary for such
Securities (or any successor securities clearing agency so registered).

----------

        (8) INSERT IF SECURITIES ARE CONVERTIBLE

        (9)  INSERT IF SECURITIES ARE CONVERTIBLE

                                      -4-

<PAGE>

        "Designated Senior Debt" means 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).

         "Dollar" or "U.S. $" means a dollar or other equivalent unit in such
coin or currency of the United States as at the time shall be legal tender for
the payment of public and private debts.

        "DTC" means The Depository Trust Company, a New York corporation.

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

        "Exchange Act" means the United States Securities Exchange Act of 1934
(or any successor statute), as amended from time to time.

        "Global Security" means a Security that is registered in the Security
Register in the name of a Depositary or a nominee thereof.

        "Holder" means the Person in whose name the 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.

        "Interest Payment Date" means the Stated Maturity of an installment of
interest on the Securities.

        "Issue Date" means ____________, ______.

        "Make-Whole Payment" has the meaning specified in Section 2.2.

        "Maturity", when used with respect to any Security, means the date on
which the principal of such Security becomes due and payable as therein or
herein provided, whether at the Stated Maturity or by declaration of
acceleration, call for redemption, exercise of the repurchase right set forth in
Article XIV or otherwise.

                                       -5-

<PAGE>

         ["Non-electing Share" has the meaning specified in Section 12.11.](10)

         "Notice Date" has the meaning specified in Section 2.2.

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

         "Officers' Certificate" means a certificate signed by (i) the Chairman
of the Board, a Vice Chairman of the Board, the Chief Executive Officer, the
President, an Executive Vice President or a Vice President and by (ii) 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 10.8 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 the Company (including internal counsel) and who shall be reasonably
acceptable to the Trustee.

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

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

                 (ii) Securities for the payment or redemption of which 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;

                 (iii) 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[; and

                 (iv) Securities converted into Common Stock pursuant to
         Article XII](11);

  provided, however, that in determining whether the Holders of the requisite
  principal amount of Outstanding Securities are present at a meeting of Holders
  for quorum purposes or have given, made or taken any request, demand,
  authorization, direction, notice, consent or waiver or other

----------

        (10) INSERT IF SECURITIES ARE CONVERTIBLE

        (11) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -6-

<PAGE>

action hereunder as of any date, Securities owned by the Company or any other
obligor upon the Securities or any Affiliate of the Company or such other
obligor shall be disregarded and deemed not to be Outstanding, except that, in
determining whether the Trustee shall be protected in relying upon any such
determination as to the presence of a quorum or upon any such request, demand,
authorization, direction, notice, consent, waiver or other action, only
Securities which a Responsible Officer of the Trustee has been notified in
writing 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 is not
the Company or any other obligor upon the Securities or any Affiliate of the
Company or such other obligor, and the Trustee shall be protected in relying
upon an Officers' Certificate to such effect.

         "Over-allotment Option" has the meaning specified in Section 3.1.

         "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 and, except as otherwise specifically set forth herein, such term shall
include the Company if it shall act as its own Paying Agent. The Company has
initially appointed the Trustee as its Paying Agent pursuant to Section 10.2
hereof.

         "Payment Blockage Notice" has the meaning specified in Section 13.2.

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

         ["Place of Conversion" has the meaning specified in Section 3.1.](12)

         "Place of Payment" has the meaning specified in 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.

         "Privately Placed Note" means that certain 4.75% Convertible
Subordinated Note Due 2006, No. R-1 issued by the Company to the holder
thereof on May 1, 2001, in the aggregate principal amount of $10,000,000.

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

         "Record Date Period" means the period from the close of business of any
Regular Record Date next preceding any Interest Payment Date to the opening of
business on such Interest Payment Date.

----------

        (12) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -7-

<PAGE>

         "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 interest payable in respect of any Security
on any Interest Payment Date means the ___________ or __________ (whether or not
a Business Day), as the case may be, next preceding such Interest Payment Date.

         "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.

         "Repurchase Date" has the meaning specified in Section 14.1.

         "Repurchase Price" has the meaning specified in Section 14.1.

         "Responsible Officer", when used with respect to the Trustee, means any
officer within the Corporate Trust Office of the Trustee, including without
limitation, any vice president, assistant vice president, assistant treasurer,
corporate trust officer or other employee of the Trustee customarily performing
functions similar to those performed by any of the above designated officers,
and also means, with respect to a particular corporate trust matter, any other
officer to whom such matter is referred because of his knowledge and familiarity
with the particular subject.

         "Securities" has the meaning ascribed to it in the first paragraph
under the caption "Recitals of the Company" and more particularly means any
Securities authenticated and delivered under this Indenture.

         "Securities Act" means the United States Securities Act of 1933 (or any
successor statute), as amended from time to time.

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

         "Senior Debt" means the principal of (and premium, if any) and 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) on, and all fees,
expenses and other amounts payable in connection with, the following, whether

                                      -8-

<PAGE>

absolute or contingent, secured or unsecured, due or to become due,
outstanding on the date of this Indenture or thereafter created, incurred or
assumed: (a) indebtedness of the Company evidenced by a credit or loan
agreement, note, bond, debenture or other written obligation (including
without limitation indebtedness that is convertible or exchangeable for
securities of the Company), (b) all obligations of the Company for money
borrowed, (c) all obligations of the Company evidenced by a note or similar
instrument given in connection with the acquisition of any businesses,
properties or assets of any kind, (d) obligations of the Company (i) as
lessee under leases required or permitted to be capitalized on the balance
sheet of the lessee under generally accepted accounting principles and (ii)
as lessee under other leases for facilities, equipment or other assets,
whether or not capitalized, entered into or leased for financing purposes
(including so-called "synthetic leases"), as determined in good faith by the
Company, (e) all obligations of the Company under interest rate and currency
swaps, caps, floors, collars, hedge agreements, currency spot and forward
contracts or similar agreements or arrangements including, without
limitation, agreements and arrangements intended to protect the Company from
fluctuations in interest or currency exchange rates or commodity prices, (f)
all obligations of the Company with respect to letters of credit, bankers'
guarantees or bankers' acceptances and similar facilities (including
reimbursement obligations with respect to the foregoing), (g) all standby
fees due and payable to lending institutions with respect to credit
facilities or letters of credit, (h) all obligations of the Company issued or
assumed as the deferred purchase price of any business, property, assets
(including intangibles) or services (but excluding trade accounts payable and
accrued liabilities that constitute liabilities arising in the ordinary
course of business as determined in good faith by the Company), (i) all
obligations of the type referred to in clauses (a) through (h) above of
another Person and all dividends of another Person, the payment of which, in
either case, the Company has assumed or guaranteed, or for which the Company
is responsible or liable, directly or indirectly, jointly or severally, as
obligor, guarantor or otherwise, or which is secured by a lien on the
property of the Company, and (j) renewals, extensions, deferrals,
modifications, amendments, replacements, restatements and refundings of, or
any indebtedness or obligation issued in exchange for, any such indebtedness
or obligation described in clauses (a) through (i) of this paragraph;
provided, however, that Senior Debt shall not include the Securities, the
Privately Placed Note, or any such indebtedness or obligation if the terms of
such indebtedness or obligation (or the terms of the instrument under which,
or pursuant to which it is issued) expressly provide that such indebtedness
or obligation is not superior in right of payment to the Securities.

         "Significant Subsidiary" means, with respect to any Person, a
Subsidiary of such Person that would constitute a "significant subsidiary" as
such term is defined under Rule 1-02 of Regulation S-X under the Securities Act
and the Exchange Act.

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

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

                                      -9-

<PAGE>

         "Subsidiary" means a corporation more than 50% of the outstanding
voting stock of which is owned, directly or indirectly, by the Company or by one
or more other Subsidiaries, or by the Company and one or more other
Subsidiaries. For the purposes of this definition, "voting stock" means stock or
other similar interests in the corporation which ordinarily has or have voting
power for the election of directors, or persons performing similar functions,
whether at all times or only so long as no senior class of stock or other
interests has or have such voting power by reason of any contingency.

         "Successor Security" of any particular Security means every Security
issued after, and 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.

         "Trading Day" means (i) if the Common Stock is quoted on the Nasdaq
National Market or any other system of automated dissemination of quotations of
securities prices, days on which trades may be effected through such system,
(ii) if the Common Stock is listed or admitted for trading on any national or
regional securities exchange, days on which such national or regional securities
exchange is open for business, or (iii) if the Common Stock is not listed on a
national or regional securities exchange or quoted on the Nasdaq National Market
or any other system of automated dissemination of quotation of securities
prices, days on which the Common Stock is traded regular way in the over-the-
counter market and for which a closing bid and a closing asked price for the
Common Stock are available.

         "Trust Indenture Act" means the Trust Indenture Act of 1939, and the
rules and regulations thereunder, 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,
and the rules and regulations thereunder, 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 such successor Trustee.

         "Underwriting Agreement" means the Underwriting Agreement, dated as of
____________________, ______, among the Company and
_____________________________, as underwriters relating to the offering and sale
of the Securities.

         "United States" means the United States of America (including the
States and the District of Columbia), its territories, its possessions and other
areas subject to its jurisdiction (its "possessions" including Puerto Rico, the
U.S. Virgin Islands, Guam, American Samoa, Wake Island and the Northern Mariana
Islands).

                                      -10-

<PAGE>

         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 an Officers' Certificate stating that all conditions precedent, if
any, provided for in this Indenture relating to the proposed action have been
complied with and, if required by the Trust Indenture Act, an Opinion of Counsel
stating that in the opinion of such counsel all such conditions precedent, if
any, have been complied with, except that in the case of any such application or
request as to which the furnishing of such documents is specifically required by
any provision of this Indenture relating to such particular application or
request, no additional certificate or opinion need be furnished.

         Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture (including certificates
provided for in Section 10.7) shall include:

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

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

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

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

         SECTION 1.3 FORM OF DOCUMENTS DELIVERED TO THE 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 such 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

                                      -11-

<PAGE>

Company or any other Person stating that the information with respect to such
factual matters is in the possession of the Company or such other Person, unless
such counsel knows 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.

         (1) 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 (A) one or more
instruments of substantially similar tenor signed by such Holders in person or
by an agent or proxy duly appointed in writing by such Holders or (B) the record
of Holders voting in favor thereof, either in person or by proxies duly
appointed in writing, at any meeting of Holders duly called and held in
accordance with the provisions of Article IX. Such action shall become effective
when such instrument or instruments or record is 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 instruments and records
delivered to the Trustee. Such instrument or instruments and records (and the
action embodied therein and evidenced thereby) are herein sometimes referred to
as the "Act" of the Holders signing such instrument or instruments and so voting
at such meeting. Proof of execution of any such instrument or of a writing
appointing any such agent or proxy, or of the holding by any Person of a
Security, 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 record of any meeting of Holders shall be
proved in the manner provided in Section 9.6.

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

         (3) The principal amount and serial number of any Security held by any
Person, and the date of his holding the same, shall be proved by the Security
Register.

         (4) The fact and date of execution of any such instrument or writing
and the authority of the Person executing the same may also be proved in any
other manner which the Trustee deems sufficient; and the Trustee may in any
instance require further proof with respect to any of the matters referred to in
this Section 1.4.

                                      -12-

<PAGE>

         (5) The Company may set any day as the record date for the purpose of
determining the Holders entitled to give or take any request, demand,
authorization, direction, notice, consent, waiver or other action, or to vote on
any action, authorized or permitted by this Indenture to be given or taken by
Holders. Promptly and in any case not later than ten days after setting a record
date, the Company shall notify the Trustee and the Holders of such record date.
If not set by the Company prior to the first solicitation of a Holder made by
any Person in respect of any such action, or, in the case of any such vote,
prior to such vote, the record date for any such action or vote shall be the
30th day (or, if later, the date of the most recent list of Holders required to
be provided pursuant to Section 15.1) prior to such first solicitation or vote,
as the case may be. With regard to any record date, the Holders on such date (or
their duly appointed agents or proxies), and only such Persons, shall be
entitled to give or take, or vote on, the relevant action, whether or not such
Holders remain Holders after such record date. Notwithstanding the foregoing,
the Company shall not set a record date for, and the provisions of this
paragraph shall not apply with respect to, any notice, declaration or direction
referred to in the next paragraph.

         Upon receipt by the Trustee from any Holder of (i) any notice of
default or breach referred to in Section 5.1(4) or 5.1(5), if such default or
breach has occurred and is continuing and the Trustee shall not have given such
a notice to the Company, (ii) any declaration of acceleration referred to in
Section 5.2, if an Event of Default has occurred and is continuing and the
Trustee shall not have given such a declaration to the Company, or (iii) any
direction referred to in Section 5.12, if the Trustee shall not have taken the
action specified in such direction, then, with respect to clauses (ii) and
(iii), a record date shall automatically and without any action by the Company
or the Trustee be set for determining the Holders entitled to join in such
declaration or direction, which record date shall be the close of business on
the tenth day (or, if such day is not a Business Day, the first Business Day
thereafter) following the day on which the Trustee receives such declaration or
direction, and, with respect to clause (i), the Trustee may set any day as a
record date for the purpose of determining the Holders entitled to join in such
notice of default. Promptly after such receipt by the Trustee of any such
declaration or direction referred to in clause (ii) or (iii), and promptly after
setting any record date with respect to clause (i), and as soon as practicable
thereafter, the Trustee shall notify the Company and the Holders of any such
record date so fixed. The Holders on such record date (or their duly appointed
agents or proxies), and only such Persons, shall be entitled to join in such
notice, declaration or direction, whether or not such Holders remain Holders
after such record date; provided that, unless such notice, declaration or
direction shall have become effective by virtue of Holders of the requisite
principal amount of Securities on such record date (or their duly appointed
agents or proxies) having joined therein on or prior to the 90th day after such
record date, such notice, declaration or direction shall automatically and
without any action by any Person be canceled and of no further effect. Nothing
in this paragraph shall be construed to prevent a Holder (or a duly appointed
agent or proxy thereof) from giving, before or after the expiration of such
90-day period, a notice, declaration or direction contrary to or different from,
or, after the expiration of such period, identical to, the notice, declaration
or direction to which such record date relates, in which event a new record date
in respect thereof shall be set pursuant to this paragraph. In addition, nothing
in this paragraph shall be construed to render ineffective any notice,
declaration or direction of the type referred to in this paragraph given at any
time to the Trustee and the

                                      -13-

<PAGE>

Company by Holders (or their duly appointed agents or proxies) of the requisite
principal amount of Securities on the date such notice, declaration or direction
is so given.

         (6) Except as provided in Sections 5.12 and 5.13, any request, demand,
authorization, direction, notice, consent, election, 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.

         (7) The provisions of this Section 1.4 are subject to the provisions of
Section 9.5.

         SECTION 1.5 NOTICES, ETC. TO THE TRUSTEE AND THE COMPANY.

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

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

         (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, mailed, first-class postage prepaid, or telecopied and confirmed by
mail, first-class postage prepaid, or delivered by hand or overnight courier,
addressed to the Company at 5 Carlisle Road, Westford, Massachusetts 01886,
Attention: Chief Financial Officer, or at any other address previously furnished
in writing to the Trustee by the Company.

         SECTION 1.6  NOTICE TO HOLDERS; WAIVER.

         Except as otherwise expressly provided herein, where this Indenture
provides for notice to Holders of any event, such notice shall be sufficiently
given to Holders if in writing and mailed, first-class postage prepaid or
delivered by an overnight delivery service, to each Holder affected by such
event, at the address of such Holder as it appears in the Security Register, not
earlier than the earliest date and not later than the latest date prescribed for
the giving of such notice.

         Neither the failure to mail such notice, nor any defect in any notice
so mailed, to any particular Holder shall affect the sufficiency of such notice
with respect to other Holders. 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 to Holders as shall be made in

                                      -14-

<PAGE>

such manner with the approval of the Trustee, which approval shall not be
unreasonably withheld or delayed, shall constitute a sufficient notification to
such Holders for every purpose hereunder.

         Such notice shall be deemed to have been given when such notice is
received.

         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.

         SECTION 1.7 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 1.8 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 1.9 SEPARABILITY CLAUSE.

         In case any provision in this Indenture or 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 1.10 BENEFITS OF INDENTURE.

         Except as provided in the next sentence, nothing in this Indenture or
in the Securities, express or implied, shall give to any Person, other than the
parties hereto and their successors and assigns hereunder and the Holders, any
benefit or legal or equitable right, remedy or claim under this Indenture. The
provisions of Article XIII are intended to be for the benefit of, and shall be
enforceable directly by, the holders of Senior Debt.

         SECTION 1.11 GOVERNING LAW.

         THIS INDENTURE AND THE SECURITIES SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, THE UNITED STATES OF AMERICA,
WITHOUT REGARD TO THE CONFLICTS OF LAWS PRINCIPLES THEREOF.

                                      -15-

<PAGE>

         SECTION 1.12 LEGAL HOLIDAYS.

         In any case where any Interest Payment Date, Redemption Date,
Repurchase Date or Stated Maturity of any Security [or the last day on which a
Holder has a right to convert his Security(13)] shall not be a Business Day at a
Place of Payment [or Place of Conversion, as the case may be](14), then
(notwithstanding any other provision of this Indenture or of the Securities)
payment of principal of, premium, if any, or interest on, or the payment of the
Redemption Price or Repurchase Price (whether the same is payable in cash or in
shares of Common Stock) with respect to[, or delivery for conversion of,](15)
such Security need not be made at such Place of Payment [or Place of Conversion,
as the case may be,](16) on or by such day, but may be made on or by the next
succeeding Business Day at such Place of Payment [or Place of Conversion, as the
case may be,](17) with the same force and effect as if made on the Interest
Payment Date, Redemption Date or Repurchase Date, or at the Stated Maturity [or
by such last day for conversion](18); provided, however, that in the case that
payment is made on such succeeding Business Day, no interest shall accrue on the
amount so payable for the period from and after such Interest Payment Date,
Redemption Date, Repurchase Date, Stated Maturity [or last day for
conversion](19), as the case may be.

         SECTION 1.13 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 that 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. Until such time as this Indenture shall be qualified under the Trust
Indenture Act, this Indenture, the Company and the Trustee shall be deemed for
all purposes hereof to be subject to and governed by the Trust Indenture Act to
the same extent as would be the case if this Indenture were so qualified on the
date hereof.

----------

        (13) INSERT IF SECURITIES ARE CONVERTIBLE

        (14) INSERT IF SECURITIES ARE CONVERTIBLE

        (15) INSERT IF SECURITIES ARE CONVERTIBLE

        (16) INSERT IF SECURITIES ARE CONVERTIBLE

        (17) INSERT IF SECURITIES ARE CONVERTIBLE

        (18) INSERT IF SECURITIES ARE CONVERTIBLE

        (19) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -16-

<PAGE>

                                   ARTICLE II

                                 SECURITY FORMS

         SECTION 2.1 FORM GENERALLY.

         The Securities shall be in substantially the form set forth in this
Article, 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, the Internal Revenue Code of 1986, as amended, and
regulations thereunder (the "Code"), or as may, consistent herewith, be
determined by the officers executing such Securities, as evidenced by their
execution thereof. All Securities shall be issued in registered form, as opposed
to bearer form.

         The Trustee's certificates of authentication shall be in substantially
the form set forth in Section 2.3.

         [Conversion notices shall be in substantially the form set forth in
Section 2.4.](20)

         Repurchase notices shall be substantially in the form set forth in
Section 2.2.

         The Securities shall be printed, lithographed, typewritten or engraved
or produced by any combination of these methods or may be produced in any other
manner permitted by the rules of any automated quotation system or securities
exchange (including on steel engraved borders if so required by any securities
exchange upon which the Securities may be listed) on which the Securities may be
quoted or listed, as the case may be or, if the Securities are not listed on a
securities exchange or automated quotation system, in any other manner approved
by the Company, all as determined by the officers executing such Securities, as
evidenced by their execution thereof.

         Upon their original issuance, Securities shall be issued in the form of
one or more Global Securities without interest coupons and shall be registered
in the name of DTC, as Depositary, or its nominee and deposited with the
Trustee, as custodian for DTC, for credit by DTC to the respective accounts of
beneficial owners of the Securities represented thereby (or such other accounts
as they may direct).

         SECTION 2.2 FORM OF SECURITY.

[FORM OF FACE]

         [THE FOLLOWING LEGEND SHALL APPEAR ON THE FACE OF EACH GLOBAL SECURITY:

----------

        (20) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -17-

<PAGE>

         THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE
HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF THE DEPOSITARY OR A
NOMINEE OF THE DEPOSITARY, WHICH MAY BE TREATED BY THE COMPANY, THE TRUSTEE AND
ANY AGENT THEREOF AS OWNER AND HOLDER OF THIS SECURITY FOR ALL PURPOSES.

         THE FOLLOWING LEGEND SHALL APPEAR ON THE FACE OF EACH GLOBAL SECURITY
FOR WHICH THE DEPOSITORY TRUST COMPANY IS TO BE THE DEPOSITARY:

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

         UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN
DEFINITIVE REGISTERED FORM IN THE LIMITED CIRCUMSTANCES REFERRED TO IN THE
INDENTURE, THIS GLOBAL SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE
DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO
THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY
SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR
DEPOSITARY.]

                              SONUS NETWORKS, INC.

______% [CONVERTIBLE](21) SUBORDINATED NOTE DUE _________________, ____

No.____  $ __________________

CUSIP NO. ___________

         SONUS NETWORKS, INC., a corporation duly organized and existing under
the laws of the State of Delaware (herein called the "Company", which term
includes any successor Person

----------

        (21) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -18-

<PAGE>

under the Indenture referred to on the reverse hereof), for value received,
hereby promises to pay to _________________, or registered assigns, the
principal sum of ________ United States Dollars (U.S.$______ ) (which
principal amount may from time to time be increased or decreased to such
other principal amounts (which, taken together with the principal amounts of
all other Outstanding Securities, shall not exceed $___________ (or
$___________ if the Over-allotment Option is exercised in full)) by
adjustments made on the records of the Trustee hereinafter referred to in
accordance with the Indenture) on __________________, ______ and to pay
interest thereon, from _________, _____, or from the most recent Interest
Payment Date (as defined below) to which interest has been paid or duly
provided for, semi-annually in arrears on __________________ and
__________________ in each year (each, an "Interest Payment Date"),
commencing _______, _____, at the rate of _____% per annum, until the
principal hereof is due, and at the rate of _____% per annum on any overdue
principal and premium, if any, and, to the extent permitted by law, on any
overdue interest. The interest so payable, and punctually paid or duly
provided for, on any Interest Payment Date will, as provided in the
Indenture, be paid to the Person in whose name this 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. Except as otherwise provided in the Indenture, 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 Company, notice
whereof shall be given to Holders 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 automated quotation system or
securities exchange on which the Securities may be quoted or listed, and upon
such notice as may be required by such exchange, all as more fully provided
in the Indenture. Payments of principal shall be made upon the surrender of
this Security at the option of the Holder at the Corporate Trust Office of
the Trustee, or at such other office or agency of the Company as may be
designated by it for such purpose in the Borough of Manhattan, The City of
New York, in such lawful monies of the United States of America as at the
time of payment shall be legal tender for the payment of public and private
debts, or at such other offices or agencies as the Company may designate, by
United States Dollar check drawn on, or wire transfer to, a United States
Dollar account (such a wire transfer to be made only to a Holder of an
aggregate principal amount of Securities in excess of U.S. $2,000,000 and
only if such Holder shall have furnished wire instructions in writing to the
Trustee no later than 15 days prior to the relevant payment date) maintained
by the payee with a bank in the Borough of Manhattan, The City of New York.
Payment of interest on this Security may be made by United States Dollar
check mailed to the address of the Person entitled thereto as such address
shall appear in the Security Register, or, upon written application by the
Holder to the Security Registrar setting forth wire instructions not later
than the relevant Record Date, by wire transfer to a United States Dollar
account (such a wire transfer to be made only to a Holder of an aggregate
principal amount of Securities in excess of U.S. $2,000,000 and only if such
Holder shall have furnished wire instructions in writing to the Trustee no
later than 15 days prior to the relevant payment date) maintained by the
payee with a bank in the Borough of Manhattan, The

                                      -19-

<PAGE>

City of New York. Except as specifically provided herein and in the Indenture,
the Company shall not be required to make any payment with respect to any tax,
assessment or other governmental charge imposed by any government or any
political subdivision or taxing authority thereof or therein.

         Interest on the Securities shall be computed on the basis of a
360-day year of twelve 30-day months.

         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 or an Authenticating Agent by the
manual signature of one of their respective authorized signatories, 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 Security to be duly
executed.

                                       SONUS NETWORKS, INC.

                                       By:
                                          _____________________________________
                                       Name:
                                       Title:

Attest:

By:
   ________________________________
Name:
Title:

TRUSTEE'S CERTIFICATE OF AUTHENTICATION

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

     Dated:______________________________
     as Trustee

     By:
        ________________________________
        Authorized Signatory

                                [FORM OF REVERSE]

                                      -20-

<PAGE>

This Security is one of a duly authorized issue of securities of the Company
designated as its "_____% [Convertible](22) Subordinated Notes due
__________________" (herein called the "Securities"), limited in aggregate
principal amount to U.S. $___________ (or $___________ if the Over-allotment
Option is exercised in full), issued and to be issued under an Indenture, dated
as of _______________, _____ (herein called the "Indenture"), between the
Company and _________________, as Trustee (herein called the "Trustee", which
term includes any successor trustee under the Indenture), and to which Indenture
and all indentures supplemental thereto reference is hereby made for a statement
of the respective rights, limitations of rights, duties and immunities
thereunder of the 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. As provided in the Indenture and subject
to certain limitations therein set forth, Securities are exchangeable for a like
aggregate principal amount of Securities of any authorized denominations as
requested by the Holder surrendering the same upon surrender of the Security or
Securities to be exchanged, at the Corporate Trust Office of the Trustee. The
Trustee upon such surrender by the Holder will issue the new Securities in the
requested denominations. No sinking fund is provided for the Securities. The
Securities are subject to redemption by the Company, in whole or in part, at any
time prior to __________________, ________, upon notice as set forth in Section
11.5 of the Indenture, at a redemption price equal to the principal amount of
the Securities to be redeemed plus accrued and unpaid interest, if any, to the
Redemption Date if the Closing Price of the Common Stock shall have
________________ for at least 20 Trading Days in any 30-Trading Day period
ending on the Trading Day prior to the date of mailing of the notice of
redemption pursuant to Section 11.5 of the Indenture (the "Notice Date"). Upon
any such redemption, the Company shall make an additional payment (the
"Make-Whole Payment") with respect to the Securities called for redemption to
holders on the Notice Date in an amount equal to $_______ per U.S. $1,000
Security, less the amount of any interest actually paid on such Security prior
to the Notice Date. The Company shall make the Make-Whole Payment on all
Securities called for redemption[,including any Securities converted into Common
Stock pursuant to the terms of the Indenture after the Notice Date and prior to
the Redemption Date.](23) The Company may make the Make-Whole Payment, at its
option, in cash, in shares of Common Stock or through a combination of cash and
shares of Common Stock. For purposes of this paragraph, the fair market value of
shares of Common Stock shall be determined by the Company and shall be equal to
___% of the average of the Closing Price Per Share for the five consecutive
Trading Days immediately preceding the Redemption Date.

         The Securities are also subject to redemption at the option of the
Company at any time on or after __________________,___ in whole or in part, upon
not less than 30 nor more than 60 days notice to the Holders prior to the
Redemption Date at the Redemption Prices (expressed as percentages of the
principal amount) set forth below.

----------

        (22) INSERT IF SECURITIES ARE CONVERTIBLE

        (23) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -21-

<PAGE>

         The following table sets forth the Redemption Prices (expressed as
percentages of the principal amount) if such Security is redeemed during the
12-month period beginning on __________ of the following years:

<TABLE>
<CAPTION>
YEAR                             REDEMPTION PRICE
<S>                              <C>
</TABLE>

and thereafter at a Redemption Price equal to _____% of the principal amount,
together, in each case, with accrued interest to the Redemption Date; provided,
however, that interest installments on Securities 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.

         In the event of a redemption of the Securities, the Company will not be
required (a) to register the transfer or exchange of Securities for a period of
15 days immediately preceding the date notice is given identifying the serial
numbers of the Securities called for such redemption or (b) to register the
transfer or exchange of any Security, or portion thereof, called for redemption.
In any case where the due date for the payment of the principal of, premium, if
any, or interest on any Security [or the last day on which a Holder has a right
to convert his Security](24) shall be, at any Place of Payment [or Place of
Conversion, as the case may be,](25) a day on which banking institutions at such
Place of Payment [or Place of Conversion](26) are authorized or obligated by law
or executive order to close, then payment of principal, premium, if any, or
interest, [or delivery for conversion of such Security](27) need not be made on
or by such date at such place but may be made on or by the next succeeding day
at such place which is not a day on which banking institutions are authorized or
obligated by law or executive order to close, with the same force and effect as
if made on the date for such payment or the date fixed for redemption or
repurchase[, or by such last day for conversion,](28) and no interest shall
accrue on the amount so payable for the period from and after such due date.

         [Subject to and upon compliance with the provisions of the Indenture,
the Holder of this Security is entitled, at his option, at any time on or before
the close of business on the date of

----------

        (24) INSERT IF SECURITIES ARE CONVERTIBLE

        (25) INSERT IF SECURITIES ARE CONVERTIBLE

        (26) INSERT IF SECURITIES ARE CONVERTIBLE

        (27) INSERT IF SECURITIES ARE CONVERTIBLE

        (28) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -22-

<PAGE>

Maturity, or in case this Security or a portion hereof is called for redemption
or the Holder hereof has exercised his right to require the Company to
repurchase this Security or such portion hereof, then in respect of this
Security until and including, but (unless the Company defaults in making the
payment due upon redemption or repurchase, as the case may be) not after, the
close of business on the Business Day immediately preceding the Redemption Date
or the Repurchase Date, as the case may be, to convert this Security (or any
portion of the principal amount hereof that is an integral multiple of
U.S.$1,000, provided that the unconverted portion of such principal amount is an
integral multiple of U.S.$1,000) into fully paid and nonassessable shares of
Common Stock of the Company at an initial Conversion Rate of ______ shares of
Common Stock for each U.S.$1,000 principal amount of Securities (or at the
current adjusted Conversion Rate if an adjustment has been made as provided in
the Indenture) by surrender of this Security, duly endorsed or assigned to the
Company or in blank and, in case such surrender shall be made during the period
from the close of business on any Regular Record Date next preceding any
Interest Payment Date to the opening of business on such Interest Payment Date
(except if this Security or portion thereof has been called for redemption on a
Redemption Date or is repurchasable on a Repurchase Date occurring, in either
case, during such period and, as a result, the right to convert would terminate
in such period), also accompanied by payment in New York Clearing House or other
funds acceptable to the Company of an amount equal to the interest payable on
such Interest Payment Date on the principal amount of this Security then being
converted, and also the conversion notice hereon duly executed, to the Company
at the Corporate Trust Office of the Trustee, or at such other office or agency
of the Company, subject to any laws or regulations applicable thereto and
subject to the right of the Company to terminate the appointment of any
Conversion Agent (as defined below) as may be designated by it for such purpose
in the Borough of Manhattan, The City of New York, or at such other offices or
agencies as the Company may designate in the Borough of Manhattan, The City of
New York (each a "Conversion Agent"), provided, further, that if this Security
or portion hereof has been called for redemption on a Redemption Date or is
repurchasable on a Repurchase Date occurring, in either case, during the period
from the close of business on any Regular Record Date next preceding any
Interest Payment Date to the opening of business on such succeeding Interest
Payment Date, and is surrendered for conversion during such period, then the
Holder of this Security on such Regular Record Date will be entitled to receive
the interest accruing hereon from the Interest Payment Date next preceding the
date of such conversion to such succeeding Interest Payment Date and the Holder
of this Security who converts this Security or a portion hereof during such
period shall not be required to pay such interest upon surrender of this
Security for conversion. Subject to the provisions of the preceding sentence
and, in the case of a conversion after the close of business on the Regular
Record Date next preceding any Interest Payment Date and on or before the close
of business on such Interest Payment Date, to the right of the Holder of this
Security (or any Predecessor Security of record as of such Regular Record Date)
to receive the related installment of interest to the extent and under the
circumstances provided in the Indenture, no cash payment or adjustment is to be
made on conversion for interest accrued hereon from the Interest Payment Date
next preceding the day of conversion, or for dividends on the Common Stock
issued on conversion hereof. The Company shall thereafter deliver to the Holder
the fixed number of shares of Common Stock (together with any cash adjustment,
as provided in the Indenture) into which this Security is convertible and such
delivery will be

                                      -23-

<PAGE>

deemed to satisfy the Company's obligation to pay the principal amount of this
Security. No fractions of shares or scrip representing fractions of shares will
be issued on conversion, but instead of any fractional interest (calculated to
the nearest 1/100th of a share) the Company shall pay a cash adjustment as
provided in the Indenture. The Conversion Rate 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 (other than a
consolidation or merger that does not result in any reclassification,
conversion, exchange or cancellation of the Common Stock) or the conveyance,
transfer, sale or lease of all or substantially all of the property and assets
of the Company, the Indenture shall be amended, without the consent of any
Holders, 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 such consolidation, merger, conveyance, transfer, sale or lease
by a holder of the number of shares of Common Stock of the Company into which
this Security could have been converted immediately prior to such consolidation,
merger, conveyance, transfer, sale or lease (assuming such holder of Common
Stock is not a Constituent Person, 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). No adjustment in the Conversion Rate will be made until
such adjustment would require an increase or decrease of at least one percent of
such rate, provided that any adjustment that would otherwise be made will be
carried forward and taken into account in the computation of any subsequent
adjustment.](29) If a Change in Control occurs, the Holder of this Security, at
the Holder's option, shall have the right, in accordance with the provisions of
the Indenture, to require the Company to repurchase this Security (or any
portion of the principal amount hereof that is equal to an integral multiple of
$1,000, provided that the portion of the principal amount of this Security to be
Outstanding after such repurchase is an integral multiple of U.S.$1,000) for
cash at a Repurchase Price equal to ____% of the principal amount thereof plus
interest accrued to the Repurchase Date. At the option of the Company as
determined prior to the time of the Change in Control, the Repurchase Price may
be paid in cash or, subject to the conditions provided in the Indenture, by
delivery of shares of Common Stock having a fair market value equal to the
Repurchase Price. For purposes of this paragraph, the fair market value of
shares of Common Stock shall be determined by the Company and shall be equal to
_______% of the average of the Closing Price Per Share for the five consecutive
Trading Days immediately preceding and including the third Trading Day prior to
the Repurchase Date. Whenever in this Security there is a reference, in any
context, to the principal of any Security as of any time, such reference shall
be deemed to include reference to the Repurchase Price payable in respect of
such Security to the extent that such Repurchase Price is, was or would be so
payable at such time, and express mention of the Repurchase Price in any
provision of this Security shall not be construed as excluding the Repurchase
Price so payable in those provisions of this Security when such express mention
is not made; provided, however, that, for the purposes of the second succeeding
paragraph, such reference shall be deemed to include reference to the Repurchase
Price only to the extent the Repurchase Price is payable in cash.

----------

        (29) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -24-

<PAGE>

         The following paragraph shall appear in each Global Security:

         [In the event of a deposit or withdrawal of an interest in this
Security, including an exchange, transfer, redemption, repurchase [or
conversion](30) of this Security in part only, the Trustee, as custodian of the
Depositary, shall make an adjustment on its records to reflect such deposit or
withdrawal in accordance with the Applicable Procedures.]

         [The following paragraph shall appear in each Security that is not a
Global Security:

         In the event of redemption, repurchase [or conversion](31) of this
Security in part only, a new Security or Securities for the unredeemed,
unrepurchased [or unconverted](32) portion hereof will be issued in the name of
the Holder hereof.]

         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 an Event of Default shall occur and be continuing, the principal of
all the Securities, together with accrued interest to the date of declaration,
may be declared due and payable in the manner and with the effect provided in
the Indenture. Upon payment (i) of the amount of principal so declared due and
payable, together with accrued interest to the date of declaration, and (ii) of
interest on any overdue principal and, to the extent permitted by applicable
law, overdue interest, all of the Company's obligations in respect of the
payment of the principal of and interest on the Securities 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 under the Indenture at
any time by the Company and the Trustee with either (a) the written consent of
the Holders of not less than ___________ in principal amount of the Securities
at the time Outstanding, or (b) by the adoption of a resolution, at a meeting of
Holders of the Outstanding Securities at which a quorum is present, by the
Holders of at least _______% in aggregate principal amount of the Outstanding
Securities represented and entitled to vote at such meeting. The Indenture also
contains provisions permitting the Holders of

----------

        (30) INSERT IF SECURITIES ARE CONVERTIBLE

        (31) INSERT IF SECURITIES ARE CONVERTIBLE

        (32) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -25-

<PAGE>

specified percentages in principal amount of the Securities at the time
Outstanding, on behalf of the Holders of all the Securities, 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 in
exchange therefor or in lieu hereof whether or not notation of such consent or
waiver is made upon this Security or such other 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, the Holders of not less than 25% in principal
amount of the Outstanding Securities 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 the Securities
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, premium, if any, or interest hereon on or after the respective due dates
expressed herein [or for the enforcement of the right to convert this Security
as provided in the Indenture.](33)

         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, premium, if any, and
interest on this Security at the times, places and rate, and in the coin or
currency, herein prescribed [or to convert this Security as provided in the
Indenture.](34)

         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 Corporate
Trust Office of the Trustee or at such other office or agency of the Company as
may be designated by it for such purpose in the Borough of Manhattan, The City
of New York (which shall initially be an office or agency of the Trustee), or at
such other offices or agencies as the Company may designate, 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 thereof or his
attorney duly authorized in writing, and thereupon one or more new Securities,
of authorized denominations and for the same aggregate principal amount, will be
issued to the designated transferee or transferees by the Registrar. 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 recover any tax or other
governmental charge payable in connection therewith.

----------

        (33) INSERT IF SECURITIES ARE CONVERTIBLE

        (34) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -26-

<PAGE>

         Prior to due presentation of this Security for registration of
transfer, the Company, the Trustee, any Authenticating Agent or any other 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 Authenticating Agent or
other agent of the Company or the Trustee shall be affected by notice to the
contrary.

         No recourse for the payment of the principal (and premium, if any or
interest on this Security and no recourse under or upon any obligation, covenant
or agreement of the Company in the Indenture or any indenture supplemental
thereto 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, all such liability being, by the acceptance hereof and as
part of consideration for the issue hereof, expressly waived and released.

         THE INDENTURE AND THIS SECURITY SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, UNITED STATES OF AMERICA,
WITHOUT REGARD TO THE PRINCIPLES OF CONFLICTS OF LAWS.

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

                                  ABBREVIATIONS

         The following abbreviations, when used in the inscription of the face
of this Security, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM   as tenants in common
TEN ENT   as tenants by the entireties
JT TEN    as joint tenants with right of  survivorship and not as tenants in
          common

UNIF GIFT MIN ACT ____ Custodian ____
                  (Cust)         (Minor)
                  under Uniform Gifts
                  to Minors Act_____

         Additional abbreviations may also be used though not in the above list.

         ELECTION OF HOLDER TO REQUIRE REPURCHASE

                                      -27-

<PAGE>

         (1) Pursuant to Section 14.1 of the Indenture, the undersigned hereby
elects to have this Security repurchased by the Company.

         (2) The undersigned hereby directs the Trustee or the Company to pay it
or ______________ an amount in cash or, at the Company's election, Common Stock
valued as set forth in the Indenture, equal to ______% of the principal amount
to be repurchased (as set forth below), plus interest accrued to the Repurchase
Date, as provided in the Indenture.

Dated:

________________________________

________________________________
Signature(s)

Signature(s) must be guaranteed by an Eligible Guarantor Institution with
membership in an approved signature guarantee program pursuant to Rule 17Ad-15
under the Securities Exchange Act of 1934.

________________________________
Signature Guaranteed

Principal amount to be repurchased (an integral multiple of $1,000):

________________________________

Remaining principal amount, if any, following such repurchase (not less than
U.S. $1,000): ______________

NOTICE: The signature to the foregoing Election must correspond to the Name as
written upon the face of this Security in every particular, without alteration
or any change whatsoever.

SECTION 2.3 FORM OF CERTIFICATE OF AUTHENTICATION.

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

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

Dated:[DATE OF AUTHENTICATION]

                                      -28-

<PAGE>

_______________________________________

         ______________________________
         as Trustee

         By:
            __________________________
         Authorized Signatory

         [SECTION 2.4  FORM OF CONVERSION NOTICE.

                                CONVERSION NOTICE

         The undersigned Holder of this Security hereby irrevocably exercises
the option to convert this Security, or any portion of the principal amount
hereof (which is an integral multiple of U.S.$1,000 provided that the
unconverted portion of such principal amount is an integral multiple of
U.S.$1,000) below designated, into shares of Common Stock in accordance with the
terms of the Indenture referred to in this Security, and directs that such
shares, together with a check in payment for any fractional share and any
Securities representing any unconverted principal amount hereof, be delivered to
and be registered in the name of the undersigned unless a different name has
been indicated below. If shares of Common Stock or Securities are to be
registered in the name of a Person other than the undersigned, (a) the
undersigned will pay all transfer taxes payable with respect thereto and (b)
signature(s) must be guaranteed by an Eligible Guarantor Institution with
membership in an approved signature guarantee program pursuant to Rule 17Ad-15
under the Securities Exchange Act of 1934. Any amount required to be paid by the
undersigned on account of interest accompanies this Security.

Dated:
      ________________________________ ________________________________
                    Signature(s)

If shares or Securities are to be registered in the name of a Person other than
the Holder, please print such Person's name and address:

_______________________
(Name)

_______________________

_______________________
(Address)

Social Security or other Identification
Number, if any

                                      -29-

<PAGE>

_______________________
[Signature Guaranteed]

If only a portion of the Securities is to be converted, please indicate:

1.  Principal amount to be converted: U.S. $ ___________

2.  Principal amount and denomination of Securities representing unconverted
    principal amount to be issued:

         Amount: U.S. $___________Denominations: U.S. $____________

(any integral multiple of U.S. $1,000, provided that the unconverted portion of
such principal amount is an integral multiple of U.S. $1,000)](35)

         SECTION 2.5  FORM OF ASSIGNMENT.

         For value received ________________ hereby sell(s), assign(s) and
transfer(s) unto ________________ (Please insert social security or other
identifying number of assignee) the within Security, and hereby irrevocably
constitutes and appoints ____________________as attorney to transfer the said
Security on the books of the Company, with full power of substitution in the
premises.

Dated:
      ________________________________ ________________________________
                    Signature(s)

Signature(s) must be guaranteed by an Eligible Guarantor Institution with
membership in an approved signature guarantee program pursuant to Rule 17Ad-15
under the Securities Exchange Act of 1934.

_______________________
Signature Guaranteed

----------

        (35) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -30-
<PAGE>

                                   ARTICLE III

                                 THE SECURITIES

         SECTION 3.1 TITLE AND TERMS.

         The aggregate principal amount of Securities which may be authenticated
and delivered under this Indenture is limited to U.S. $____________ (or
$_____________ if the Over-allotment Option set forth in the Underwriting
Agreement is exercised in full (the "Over-allotment Option")), except for
Securities authenticated and delivered pursuant to Section 3.4, 3.5, 3.6, 8.5,
11.7[, 12.2](36) or 14.3(5) in exchange for, or in lieu of, other Securities
previously authenticated and delivered under this Indenture.

         The Securities shall be known and designated as the "____%
[Convertible](37) Subordinated Notes due _________, ______" of the Company.
Their Stated Maturity shall be _______________, _____ and they shall bear
interest on their principal amount from ____________, _____, payable
semi-annually in arrears on ________ and ________ in each year, commencing
_________________, ______, at the rate of ____% per annum until the principal
thereof is due and at the rate of ____% per annum on any overdue principal and,
to the extent permitted by law, on any overdue interest; provided, however, that
payments shall only be made on Business Days as provided in Section 1.12.

         The principal of, premium, if any, and interest on the Securities shall
be payable as provided in the form of Securities set forth in Section 2.2, and
the Repurchase Price, whether payable in cash or in shares of Common Stock,
shall be payable at such places as are identified in the Company Notice given
pursuant to Section 14.3 (any city in which any Paying Agent is located being
herein called a "Place of Payment").

         The Securities shall be redeemable at the option of the Company at any
time on or after _________________, ____, in whole or in part, subject to the
conditions and as otherwise provided in Article XI and in the form of Securities
set forth in Section 2.2.

         The Securities are not entitled to the benefit of any sinking fund.

         [The Securities shall be convertible as provided in Article XII (any
city in which any Conversion Agent is located being herein called a "Place of
Conversion").](38)

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

         The Securities shall be subject to repurchase by the Company at the
option of the Holders as provided in Article XIV.

----------

        (36) INSERT IF SECURITIES ARE CONVERTIBLE

        (37) INSERT IF SECURITIES ARE CONVERTIBLE

        (38) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -31-

<PAGE>

         SECTION 3.2 DENOMINATIONS.

         The Securities shall be issuable only in registered form, without
coupons, in denominations of U.S. $1,000 and integral multiples 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 President, or one of its Vice Presidents, with or without a
corporate seal reproduced thereon, and attested by its Chief Executive Officer,
President, Chief Financial Officer, Secretary or one of its Assistant
Secretaries. Any such signature may be manual or facsimile.

         Securities bearing the manual or facsimile signature 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 executed by the Company to
the Trustee or to its order for authentication, together with a Company Order
for the authentication and delivery of such Securities, and the Trustee in
accordance with such Company Order shall authenticate and make available for
delivery such Securities as in this Indenture provided and not otherwise.

         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 of an authorized signatory, and such
certificate upon any Security shall be conclusive evidence, and the only
evidence, that such Security has been duly authenticated and delivered
hereunder.

         SECTION 3.4 GLOBAL SECURITIES; NON-GLOBAL SECURITIES; BOOK-ENTRY
PROVISIONS.

         (1) Global Securities

                 (i) Each Global Security authenticated under this Indenture
         shall be registered in the name of the Depositary designated by the
         Company 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.

                 (ii) Except for exchanges of Global Securities for definitive,
         Non-global Securities at the sole discretion of the Company, no Global
         Security may be exchanged in

                                      -32-

<PAGE>

         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 as such
         under the Exchange Act or announces an intention permanently to cease
         business or does in fact do so or (B) there shall have occurred and be
         continuing an Event of Default with respect to such Global Security. In
         such event, if a successor Depositary for such Global Security is not
         appointed by the Company within 90 days after the Company receives such
         notice or becomes aware of such ineligibility, the Company will
         execute, and the Trustee, upon receipt of an Officers' Certificate
         directing the authentication and delivery of Securities, will
         authenticate and deliver, Securities, in any authorized denominations
         in an aggregate principal amount equal to the principal amount of such
         Global Security in exchange for such Global Security.

                 (iii) If any Global Security is to be exchanged for other
         Securities or canceled in whole, it shall be surrendered by or on
         behalf of the Depositary or its nominee to the Trustee, as Security
         Registrar, for exchange or cancellation, as provided in this Article
         III. If any Global Security is to be exchanged for other Securities or
         canceled in part, or if another Security is to be exchanged in whole or
         in part for a beneficial interest in any Global Security, in each case,
         as provided in Section 3.5, then either (A) such Global Security shall
         be so surrendered for exchange or cancellation, as provided in this
         Article III, or (B) the principal amount thereof shall be reduced or
         increased by an amount equal to the portion thereof to be so exchanged
         or canceled, or equal to the principal amount of such other Security to
         be so exchanged for a beneficial interest therein, as the case may be,
         by means of an appropriate adjustment made on the records of the
         Trustee, as Security Registrar, whereupon the Trustee, in accordance
         with the Applicable Procedures, shall instruct the Depositary or its
         authorized representative to make a corresponding adjustment to its
         records. Upon any such surrender or adjustment of a Global Security,
         the Trustee shall, subject to the provisions of Section 3.5 and as
         otherwise provided in this Article III, authenticate and deliver any
         Securities issuable in exchange for such Global Security (or any
         portion thereof) to or upon the order of, and registered in such names
         as may be directed by, the Depositary or its authorized representative.
         Upon the request of the Trustee in connection with the occurrence of
         any of the events specified in the preceding paragraph, the Company
         shall promptly make available to the Trustee a reasonable supply of
         Securities that are not in the form of Global Securities. The Trustee
         shall be entitled to rely upon any order, direction or request of the
         Depositary or its authorized representative which is given or made
         pursuant to this Article III if such order, direction or request is
         given or made in accordance with the Applicable Procedures.

                 (iv) 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
         Article III or otherwise, shall be authenticated and delivered in the
         form of, and shall be, a registered Global Security, unless such
         Security is registered in the name of a Person other than the
         Depositary for such Global

                                      -33-

<PAGE>

         Security or a nominee thereof, in which case such Security shall be
         authenticated and delivered in definitive, fully registered form,
         without interest coupons.

                 (v) The Depositary or its nominee, as registered owner of a
         Global Security, shall be the Holder of such Global Security for all
         purposes under the Indenture and the Securities, and owners of
         beneficial interests in a Global Security shall hold such interests
         pursuant to the Applicable Procedures. Accordingly, any such owner's
         beneficial interest in a Global Security will be shown only on, and the
         transfer of such interest shall be effected only through, records
         maintained by the Depositary or its nominee or its Agent Members and
         such owners of beneficial interests in a Global Security will not be
         considered the owners or holders thereof.

         (2) Pending the preparation of definitive Securities, the Company may
execute, and upon Company Order the Trustee shall authenticate and make
available for delivery, 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 are
issued, the Company will cause definitive Securities to be prepared without
unreasonable delay. After the preparation of definitive Securities, the
temporary Securities shall be exchangeable for definitive Securities upon
surrender of the temporary Securities at any office or agency of the Company
designated pursuant to Section 10.2, without charge to the Holder. Upon
surrender for cancellation of any one or more temporary Securities the Company
shall execute and the Trustee shall authenticate and make available for delivery
in exchange therefor a like principal amount of definitive Securities of
authorized denominations. Until so exchanged the temporary Securities shall in
all respects be entitled to the same benefits under this Indenture as definitive
Securities.

         SECTION 3.5 REGISTRATION; REGISTRATION OF TRANSFER AND EXCHANGE;
RESTRICTIONS ON TRANSFER.

         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 designated pursuant to Section 10.2 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 and exchanges of Securities as herein provided.

         Upon surrender for registration of transfer of any Security at an
office or agency of the Company designated pursuant to Section 10.2 for such
purpose, the Company shall execute, and the Trustee shall authenticate and
deliver, in the name of the designated transferee or transferees, one or more
new Securities of any authorized denominations and of a like aggregate principal
amount and bearing such restrictive legends as may be required by this
Indenture.

                                      -34-

<PAGE>

         At the option of the Holder, and subject to the other provisions of
this Section 3.5, Securities may be exchanged for other Securities of any
authorized denomination and of a like aggregate principal amount, upon surrender
of the Securities to be exchanged at any such office or agency. Whenever any
Securities are so surrendered for exchange, and subject to the other provisions
of this Section 3.5, the Company shall execute, and the Trustee shall
authenticate and deliver, the Securities which the Holder making the exchange is
entitled to receive. Every Security presented or surrendered for registration of
transfer or for exchange shall (if so required by the Company or the Security
Registrar) be duly endorsed, or be accompanied by a written instrument of
transfer in form satisfactory to the Company, the Trustee and the Security
Registrar duly executed, by the Holder thereof or his attorney duly authorized
in writing. 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.

         No service charge shall be made to a Holder for any registration of
transfer or exchange of Securities except as provided in Section 3.6, 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, 8.5[, 12.2](39) or 14.3 (other than where the shares of Common Stock are to
be issued or delivered in a name other than that of the Holder of the Security)
not involving any transfer and other than any stamp and other duties, if any,
which may be imposed in connection with any such transfer or exchange by the
United States or any political subdivision thereof or therein, which shall be
paid by the Company.

         Each Holder of a Security agrees to indemnify the Company and the
Trustee against any liability that may result from the transfer, exchange or
assignment of such Holder's Security in violation of any provision of this
Indenture and/or applicable United States Federal or state securities law.

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

         In the event of a redemption of the Securities, neither the Company nor
the Securities Registrar will be required (a) to register the transfer of or
exchange Securities for a period of 15 days immediately preceding the date
notice is given identifying the serial numbers of the Securities called for such
redemption or (b) to register the transfer of or exchange any Security, or
portion thereof, called for redemption.

         SECTION 3.6 MUTILATED, DESTROYED, LOST OR 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 like tenor and principal amount and bearing a number
not contemporaneously outstanding.

         If there shall be delivered to the Company and to the Trustee:

         (1) evidence to their satisfaction of the destruction, loss or theft of
any Security, and

----------

        (39) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -35-

<PAGE>

         (2) such security or indemnity as may be satisfactory to the Company
and the Trustee to save each of them and any agent of either of them harmless,
then, in the absence of actual 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 like tenor and principal amount and
bearing a number not contemporaneously outstanding.

         In case any such mutilated, destroyed, lost or stolen Security has
become or is about to become due and payable, the Company in its discretion [,
but subject to any conversion rights,](40) may, instead of issuing a new
Security, pay such Security, upon satisfaction of the conditions set forth in
the preceding paragraph.

         Upon the issuance of any new Security under this Section 3.6, 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 (other than any
stamp and other duties, if any, which may be imposed in connection therewith by
the United States or any political subdivision thereof or therein, which shall
be paid by the Company) and any other expenses (including the fees and expenses
of the Trustee) connected therewith.

         Every new Security issued pursuant to this Section 3.6 in lieu of any
mutilated, destroyed, lost or stolen Security shall constitute an original
additional contractual obligation of the Company, whether or not the mutilated,
destroyed, lost or stolen Security shall be at any time enforceable by anyone,
and such new Security shall be entitled to all the benefits of this Indenture
equally and proportionately with any and all other Securities duly issued
hereunder.

         The provisions of this Section 3.6 are exclusive and shall preclude (to
the extent lawful) all other rights and remedies of any Holder with respect to
the replacement or payment of mutilated, destroyed, lost or stolen Securities.

         SECTION 3.7 PAYMENT OF INTEREST; INTEREST RIGHTS PRESERVED.

         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 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

----------

        (40) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -36-
<PAGE>

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 (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, the date of the
proposed payment and the Special Record Date, 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. The Special Record Date for the payment of such Defaulted Interest
shall be not more than 15 days and not less than 10 days prior to the date of
the proposed payment and not less than 10 days after the receipt by the Trustee
of the notice of the proposed payment. The Trustee, in the name and at the
expense of the Company, shall cause notice of the proposed payment of such
Defaulted Interest and the Special Record Date therefor to be mailed,
first-class postage prepaid, to each Holder at such Holder's address as it
appears in the Security Register, not less than 10 days prior to such Special
Record Date. Notice of the proposed payment of such Defaulted Interest and the
Special Record Date therefor having been so mailed, such Defaulted Interest
shall be paid to the Persons in whose names the Securities (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 in any other
lawful manner not inconsistent with the requirements of any securities exchange
on which the 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 and Section 3.5,
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.

         [Interest on any Security which is converted in accordance with Section
12.2 during a Record Date Period shall be payable in accordance with the
provisions of Section 12.2.](41)

         SECTION 3.8 PERSONS DEEMED OWNERS.

         Prior to due presentment of a Security for registration of transfer,
the Company, the Trustee, any Paying Agent and any agent of the Company, the
Trustee or any Paying Agent may

----------

        (41) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -37-

<PAGE>

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, premium, if any,
and (subject to Section 3.7) interest on such Security and for all other
purposes whatsoever, whether or not such Security be overdue, and neither the
Company, the Trustee, any Paying Agent nor any agent of the Company, the Trustee
or any Paying Agent shall be affected by notice to the contrary.

         SECTION 3.9 CANCELLATION.

         All Securities surrendered for payment, redemption, repurchase,
registration of transfer or exchange [or conversion](42) or any Securities that
the Company may have acquired in any manner whatsoever, shall, if surrendered to
any Person other than the Trustee, be delivered to the Trustee. All Securities
so delivered to the Trustee shall be canceled promptly by the Trustee. No
Securities shall be authenticated in lieu of or in exchange for any Securities
canceled as provided in this Section 3.9. The Trustee shall dispose of all
canceled Securities in accordance with applicable law and its customary
practices in effect from time to time.

         SECTION 3.10 COMPUTATION OF INTEREST.

         Interest on the Securities shall be computed on the basis of a 360-day
year of twelve 30-day months.

         SECTION 3.11 CUSIP NUMBERS.

         The Company in issuing Securities may use "CUSIP" numbers (if then
generally in use) in addition to serial numbers; if so, the Trustee shall use
such CUSIP numbers in addition to serial numbers in notices of redemption and
repurchase as a convenience to Holders; provided that any such notice may state
that no representation is made as to the correctness of such CUSIP numbers
either as printed on the Securities or as contained in any notice of a
redemption or repurchase and that reliance may be placed only on the serial or
other identification numbers printed on the Securities, and any such redemption
or repurchase shall not be affected by any defect in or omission of such CUSIP
numbers. The Company will promptly notify the Trustee of any change in the
CUSIP numbers.

                                   ARTICLE IV

                           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 [conversion, or](43) registration of
transfer or exchange, or replacement of

----------

        (42) INSERT IF SECURITIES ARE CONVERTIBLE

        (43) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -38-

<PAGE>

Securities herein expressly provided for and the Company's obligations to the
Trustee pursuant to Section 6.7), and the Trustee, at the expense of the
Company, shall execute proper instruments in form and substance satisfactory to
the Trustee acknowledging satisfaction and discharge of this Indenture, when

         (1) either (i) all Securities theretofore authenticated and delivered
(other than (A) Securities which have been destroyed, lost or stolen and which
have been replaced or paid as provided in Section 3.6 and (B) Securities for
whose payment money has theretofore been deposited in trust or segregated and
held in trust by 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 (ii) all such Securities not theretofore delivered to the
Trustee or its agent for cancellation (other than Securities referred to in
clauses (A) and (B) of clause (1)(i) above) (a) have become due and payable, or
(b) will have become due and payable at their Stated Maturity within one year,
or (c) 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 clause (a), (b) or (c) above, has deposited or caused to be deposited
with the Trustee as trust funds (immediately available to the Holders in the
case of clause (a)) in trust for the purpose an amount in cash sufficient to pay
and discharge the entire indebtedness on such Securities not theretofore
delivered to the Trustee for cancellation, for principal, premium, if any, 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 Company to any Authenticating Agent under Section 6.12, the obligations of
the Trustee under Section 4.2 and the last paragraph of Section 10.3 and the
obligations of the Company and the Trustee under Section 3.5 [and Article
XII](44) shall survive. Funds held in trust pursuant to this Section are not
subject to the provisions of Article XIII.

         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 and in accordance with
the provisions of Article XIII shall be

----------

        (44) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -39-

<PAGE>

held in trust for the sole benefit of the Holders and not be subject to the
subordination provisions of Article XIII, and such monies shall be applied by
the Trustee, 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), to the Persons entitled
thereto, of the principal, premium, if any, and interest for whose payment such
money has been deposited with the Trustee.

         [All moneys deposited with the Trustee pursuant to Section 4.1 (and
held by it or any Paying Agent) for the payment of Securities subsequently
converted shall be returned to the Company upon Company Request.](45)

                                    ARTICLE V

                                    REMEDIES

         SECTION 5.1 EVENTS OF DEFAULT.

         "Event of Default", wherever used herein, 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 XIII or be voluntary or
involuntary or be effected by operation of law or pursuant to any judgment,
decree or order of any court or any order, rule or regulation of any
administrative or governmental body):

         (1) default in the payment of the principal of or premium, if any, on
any Security at its Maturity, whether or not such payment is prohibited by the
subordination provisions of the Securities or of this Indenture; or

         (2) default in the payment of any interest upon any Security when it
becomes due and payable, and continuance of such default for a period of 30
days, whether or such payment is prohibited by the subordination provisions of
the Securities or of this Indenture; or

         (3) failure by the Company to give a Company Notice in accordance with
Section 14.3, whether or not such Company Notice is prohibited by the
subordination provisions of the Securities or of this Indenture; 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
the performance or breach of which is specifically dealt with elsewhere in this
Section), and continuance of such default or breach for a period of 60 days
after there has been given, by registered or certified mail, to the Company by
the Trustee or to the Company and the Trustee by the Holders of at least 25% in
principal amount of the Outstanding Securities a written notice specifying such

----------

        (45) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -40-

<PAGE>

default or breach and requiring it to be remedied and stating that such notice
is a "Notice of Default" hereunder; or

         (5) a default in the payment when due (whether at stated maturity or
any acceleration thereof) of the principal of, or acceleration of, any
indebtedness under any bonds, debentures, notes or other evidences of
indebtedness for money borrowed (or guarantee thereof) by the Company or any
Significant Subsidiary or under any mortgage, indenture or instrument under
which there may be issued or by which there may be secured or evidenced any
indebtedness for money borrowed by the Company or any Significant Subsidiary (an
"Instrument") with an aggregate principal amount then outstanding in excess of
U.S. $10,000,000, whether such indebtedness now exists or shall hereafter be
created if such indebtedness is not discharged, or such acceleration is not
rescinded or annulled, within a period of 30 days after there shall have 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 a written notice specifying such default and
requiring the Company to cause such indebtedness to be discharged or cause such
default to be cured or waived or such acceleration to be rescinded or annulled
and stating that such notice is a "Notice of Default" hereunder; or

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

         (7) the commencement by the Company or any Significant Subsidiary 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 either to the entry of a decree or order for relief in respect of the
Company or any Significant Subsidiary 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 either, or the filing by either of a petition or
answer or consent seeking reorganization or similar relief under any
applicable Federal or State law, or the consent by either 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 any Significant Subsidiary or of any substantial
part of the property of either, or the making by either of an assignment for
the benefit of creditors, or the admission by either in writing of its
inability to pay its debts generally as they become due, or the taking of
corporate action by the Company or any Significant Subsidiary in furtherance
of any such action.

                                      -41-

<PAGE>

         SECTION 5.2 ACCELERATION OF MATURITY; RESCISSION AND ANNULMENT.

         If an Event of Default (other than an Event of Default specified in
Section 5.1(6) or 5.1(7) with respect to the Company) 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 may, subject to the provisions of
Article XIII, declare the principal of all the Securities 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 and all
accrued interest thereon shall become immediately due and payable. If an Event
of Default specified in Section 5.1(6) or 5.1(7) with respect to the Company
occurs, the principal amount of, and accrued interest on, all the Securities
shall, subject to the provisions of Article XIII, ipso facto become immediately
due and payable without any declaration or other Act of the Holders or any act
on the part of the Trustee.

         At any time after such declaration of acceleration 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 V provided, the Holders of a majority
in principal amount of the Outstanding Securities, by written notice to the
Company and the Trustee, may, on behalf of all Holders, rescind and annul such
declaration and its consequences if:

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

                 (i) all overdue interest on all Securities;

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

                 (iii) to the extent permitted by applicable law, interest upon
         overdue interest at a rate of _____% per annum, and (iv) all sums paid
         or advanced by the Trustee hereunder and the reasonable compensation,
         expenses, disbursements and advances of the Trustee, its agents and its
         counsel;

         (2) all Events of Default, other than the nonpayment of the principal
of, and any premium and interest on, Securities which have become due solely by
such declaration of acceleration, have been cured or waived as provided in
Section 5.13; and

         (3) such rescission and annulment would not conflict with any judgment
or decree issued in appropriate judicial proceedings regarding the payment by
the Trustee to the Holders of the amounts referred to in 5.2(1).

         No rescission or annulment referred to above shall affect any
subsequent default or impair any right consequent thereon.

                                      -42-

<PAGE>

         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
it 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 but subject to the provisions of
Article XIII 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 interest
and interest on any overdue principal and premium, if any, and, to the extent
permitted by applicable law, on any overdue interest, at a rate of _____% per
annum, and in addition thereto, such further amount as shall be sufficient to
cover the reasonable costs and expenses of collection, including the reasonable
compensation, expenses, disbursements and advances of the Trustee, its agents
and its counsel.

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

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

         SECTION 5.4 TRUSTEE MAY FILE PROOFS OF CLAIM.

         In case of the pendency of any receivership, insolvency, liquidation,
bankruptcy, reorganization, arrangement, adjustment, composition or other
judicial proceeding relative to the Company or any other obligor upon the
Securities or the property of the Company or of such other obligor or the
creditors of either, the Trustee (irrespective of whether the principal of, and
any interest on, the Securities shall then be due and payable as therein
expressed or by declaration or otherwise and irrespective of whether the Trustee
shall have made any demand on the Company for the payment of overdue principal
or interest) shall be entitled and empowered, by intervention in such proceeding
or otherwise,

                                      -43-

<PAGE>

         (1) to file and prove a claim for the whole amount of principal,
premium, if any, and interest owing and unpaid in respect of the Securities and
take such other actions, including participating as a member, voting or
otherwise, of any official committee of creditors appointed in such matter, and
to file such other papers or documents, in each of the foregoing cases, as may
be necessary or advisable in order to have the claims of the Trustee (including
any claim for the reasonable compensation, expenses, disbursements and advances
of the Trustee, its agents and its counsel) and of the Holders allowed in such
judicial proceeding, and

         (2) to collect and receive any moneys or other property payable or
deliverable on any such claim 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 to it for the reasonable compensation, expenses, disbursements and advances
of the Trustee, its agents and its counsel and any other amounts due the Trustee
under Section 6.7.

         Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder any plan of
reorganization, arrangement, adjustment or composition affecting the 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 such Holders, vote for the election of a
trustee in bankruptcy or similar official.

         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 its counsel, be for
the ratable benefit of the Holders of the Securities in respect of which
judgment has been recovered.

         SECTION 5.6 APPLICATION OF MONEY COLLECTED.

         Subject to Article XIII, any money collected by the Trustee pursuant to
this Article V 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, premium, if any, 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;

                                      -44-

<PAGE>

         SECOND: To the payment of the amounts then due and unpaid for principal
of, premium, if any, or 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, premium, if any, and interest, respectively;

         THIRD: To such other Person or Persons, if any, to the extent entitled
thereto; and

         FOURTH: Any remaining amounts shall be repaid to the Company.

         SECTION 5.7 LIMITATION ON SUITS.

         No Holder of any Security 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;

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

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

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

         (5) no direction inconsistent with such written request has been given
to the Trustee during such 60 day period by the Holders of a majority in
principal amount of the Outstanding Securities; 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
seek to obtain priority or preference over any other of such Holders or to
enforce any right under this Indenture, except in the manner herein provided and
for the equal and ratable benefit of all such Holders.

                                      -45-

<PAGE>

         SECTION 5.8 UNCONDITIONAL RIGHT OF HOLDERS TO RECEIVE PRINCIPAL,
PREMIUM AND INTEREST [AND TO CONVERT.](46)

         Notwithstanding any other provision of this Indenture, but subject to
the provisions of Article XIII, the Holder of any Security shall have the right,
which is absolute and unconditional, to receive payment of the principal of,
premium, if any, 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 or repurchase, on the Redemption Date or Repurchase Date, as the case
may be), [and to convert such Security in accordance with Article XII,](47) and
to institute suit for the enforcement of any such payment [and right to
convert](48), 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 such 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 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 Security 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 any
acquiescence therein. Every right and remedy given by this Article V or by law
to the Trustee or to the Holders may be exercised from time to time, and as
often as may be deemed expedient, by the Trustee or (subject to the limitations
contained in this Indenture) by the Holders as the case may be.

----------

        (46) INSERT IF SECURITIES ARE CONVERTIBLE

        (47) INSERT IF SECURITIES ARE CONVERTIBLE

        (48) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -46-

<PAGE>

         SECTION 5.12 CONTROL BY HOLDERS.

         Subject to Section 6.3, the Holders of a majority in principal amount
of the Outstanding Securities 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, provided that

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

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

         SECTION 5.13 WAIVER OF PAST DEFAULTS.

         The Holders, either (i) through the written consent of not less than a
majority in principal amount of the Outstanding Securities or (ii) by the
adoption of a resolution, at a meeting of Holders of the Outstanding Securities
at which a quorum is present, by the Holders of at least 66 2/3% in principal
amount of the Outstanding Securities represented at such meeting, may on behalf
of the Holders of all the Securities waive any past default hereunder and its
consequences, except a default (A) in the payment of the principal of, premium,
if any, or interest on any Security, or (B) in respect of a covenant or
provision hereof which under Article VIII cannot be modified or amended without
the consent of the Holder of each Outstanding Security affected.

         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.

         All parties to this Indenture agree, and each Holder of any Security
by his acceptance thereof shall be deemed to have agreed, that any court may
in its discretion require, in any suit for the enforcement of any right or
remedy under this Indenture, or in any suit against the Trustee for any
action taken, suffered or omitted by it as Trustee, the filing by any party
litigant in such suit of an undertaking to pay the costs of such suit, and
that such court may in its discretion assess reasonable costs, including
reasonable attorneys' fees and expenses, against any party litigant in such
suit, having due regard to the merits and good faith of the claims or
defenses made by such party litigant; but the provisions of this Section 5.14
shall not apply to any suit instituted by the Company, to any suit instituted
by the Trustee, to any suit instituted by any Holder, or group of Holders,
holding in the aggregate more than 10% in principal amount of the Outstanding
Securities, or to any suit instituted by any Holder of any Security for the
enforcement of the payment of the principal of, premium, if any, or interest
on any Security on or after the respective Stated Maturity or Maturities
expressed in such Security (or, in the case of redemption or

                                      -47-

<PAGE>

repurchase, on or after the Redemption Date or Repurchase Date, as the case may
be) [or for the enforcement of the right to convert any Security in accordance
with Article XII.](49)

         SECTION 5.15 WAIVER OF STAY, USURY 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 stay, usury 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 by reason of such law the
execution of any power herein granted to the Trustee, but will suffer and permit
the execution of every such power as though no such law had been enacted.

                                   ARTICLE VI

                                   THE TRUSTEE

         SECTION 6.1 CERTAIN DUTIES AND RESPONSIBILITIES.

         (1) Except during the continuance of an Event of Default,

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

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

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

----------

        (49) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -48-

<PAGE>

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

                 (i) this paragraph (3) shall not be construed to limit the
         effect of paragraph (1) of this Section;

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

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

                 (iv) 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.

         (4) Whether or not therein expressly so provided, every provision of
this Indenture relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section.

         SECTION 6.2 NOTICE OF DEFAULTS.

         Within 90 days after the occurrence of any default hereunder as to
which a Responsible Officer of the Trustee has received written notice, the
Trustee shall give to all Holders, in the manner provided in Section 1.6, notice
of such default, unless such default shall have been cured or waived; provided,
however, that, except in the case of a default in the payment of the principal
of, premium, if any, or interest on any Security the Trustee shall be protected
in withholding such notice if and so long as the board of directors, the
executive committee or a trust committee of directors or Responsible Officers of
the Trustee in good faith determines that the withholding of such notice is in
the interest of the Holders; and provided, further, that in the case of any
default of the character specified in Section 5.1(4), no such notice to Holders
shall be given until at least 60 days after the occurrence thereof or, if
applicable, the cure period specified therein. 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.

                                      -49-

<PAGE>

         SECTION 6.3 CERTAIN RIGHTS OF TRUSTEE.

         Subject to the provisions of Section 6.1:

         (1) the Trustee may conclusively rely, and shall be protected in
acting or refraining from acting, upon any resolution, Officers' Certificate,
other certificate, statement, instrument, opinion, report, notice, request,
direction, consent, order, bond, debenture, note, coupon, other evidence of
indebtedness or other paper or document (collectively, the "Documents")
believed by it to be genuine and to have been signed or presented by the
proper party or parties, and the Trustee need not investigate any fact or
matter stated in such Documents;

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

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

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

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

         (6) the Trustee shall not be bound to make any investigation into
the facts or matters stated in any resolution, certificate, statement,
instrument, opinion, report, notice, request, direction, consent, order,
bond, debenture, note, coupon, other evidence of indebtedness or other paper
or document, but the Trustee 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 shall incur no liability or additional liability of any
kind by reason of such inquiry or investigation; and Company shall reimburse
the reasonable out-of-pocket costs actually incurred by the Trustee in
connection with any such inquiry or investigation;

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

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

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

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

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

                                      -50-

<PAGE>

        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 the Trustee assumes no responsibility for their correctness.
The Trustee makes no representations as to the validity or sufficiency of this
Indenture, of the Securities [or of the Common Stock issuable upon the
conversion of the Securities](50). The Trustee shall not be accountable for the
use or application by the Company of Securities or the proceeds thereof.

        SECTION 6.5 MAY HOLD SECURITIES, ACT AS TRUSTEE UNDER OTHER INDENTURES.

        The Trustee, any Authenticating Agent, any Paying Agent[, any Conversion
Agent](51) or any other agent of the Company or the Trustee, in its individual
or any other capacity, may become the owner or pledgee of Securities and may
otherwise deal with the Company with the same rights it would have if it were
not Trustee, Authenticating Agent, Paying Agent[, Conversion Agent](52) or such
other agent.

        The Trustee may become and act as trustee under other indentures under
which other securities, or certificates of interest or participation in other
securities, of the Company are outstanding in the same manner as if it were not
Trustee hereunder.

        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 in writing with the Company.

        SECTION 6.7 COMPENSATION AND REIMBURSEMENT.

        The Company agrees:

        (1) to pay to the Trustee from time to time such reasonable compensation
as the Company and the Trustee shall from time to time agree in writing for all
services rendered by it hereunder (which compensation shall not be limited 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

----------

        (50) INSERT IF SECURITIES ARE CONVERTIBLE

        (51) INSERT IF SECURITIES ARE CONVERTIBLE

        (52) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -51-

<PAGE>

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 (and its directors, officers, employees
and agents) for, and to hold it harmless against, any and all loss,
liability, claim, damage or expense including taxes (other than taxes based
on the income of the Trustee) incurred without negligence or bad faith on its
part, arising out of or in connection with the acceptance or administration
of this trust, including the reasonable costs, expenses and reasonable
attorneys' fees of defending itself against any claim (whether asserted by
the Company, any Holder or any other Person) 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 in connection with
an Event of Default specified in Section 5.1(6) or Section 5.1(7), the expenses
(including the reasonable charges of its counsel) and the compensation for the
services are intended to constitute expenses of the administration under any
applicable Federal or state bankruptcy, insolvency or other similar law.

        The provisions of this Section shall survive the termination of this
Indenture or the earlier resignation or removal of the Trustee.

        SECTION 6.8 CORPORATE TRUSTEE REQUIRED; ELIGIBILITY.

        There shall at all times be a Trustee hereunder which shall be a Person
that is eligible pursuant to the Trust Indenture Act to act as such, having (or
being part of a holding company group with) a combined capital and surplus of at
least U.S. $50,000,000, subject to supervision or examination by federal or
state authority, and in good standing. The Trustee or an Affiliate of the
Trustee shall maintain an established place of business in the Borough of
Manhattan, The City of New York. If such corporation 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 corporation shall be deemed to be its
combined capital and surplus as set forth in its most recent report of condition
so published. If at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section, it shall resign immediately in
the manner and with the effect hereinafter specified in this Article and a
successor shall be appointed pursuant to Section 6.9.

        SECTION 6.9 RESIGNATION AND REMOVAL; APPOINTMENT OF SUCCESSOR.

        (1) 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 6.10.

        (2) The Trustee may resign at any time by giving written notice thereof
to the Company. If the instrument of acceptance by a successor Trustee required
by Section 6.10 shall not have been delivered to the Trustee within 30 days
after the giving of such notice of

                                      -52-

<PAGE>

resignation, the resigning Trustee may petition any court of competent
jurisdiction for the appointment of a successor Trustee. The Company shall
reimburse the reasonable out-of-pocket costs actually incurred by the Trustee
in connection with any such opinion.

        (3) The Trustee may be removed at any time by an Act of the Holders
of a majority in principal amount of the Outstanding Securities, delivered to
the Trustee and the Company. If the instrument of acceptance by a successor
Trustee required by Section 6.10 shall not have been delivered to the Trustee
within 30 days after the giving of such notice of removal, the removed
Trustee may petition any court of competent jurisdiction for the appointment
of a successor Trustee. The Company shall reimburse the reasonable
out-of-pocket costs actually incurred by the Trustee in connection with any
such petition.

        (4) If at any time:

                (i) the Trustee shall cease to be eligible under Section 6.8 and
        shall fail to resign after written request therefor by the Company or by
        any Holder who has been a bona fide Holder for at least six months,

                (ii) 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, or

                (iii) the Trustee shall fail to comply with the provisions of
        Section 6.13 after written request therefor by the Company or any Holder
        who has been a bona fide Holder for at least six months, then, in any
        such case (i) the Company by a Board Resolution may remove the Trustee,
        or (ii) subject to Section 5.14, any Holder who has been a bona fide
        Holder 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 and the appointment of a successor Trustee.

        (5) 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, the
Company, by a Board Resolution, shall promptly appoint a successor Trustee and
shall comply with the applicable requirements of this Section and Section 6.10.
If, within one year after such resignation, removal or incapability, or the
occurrence of such vacancy, a successor Trustee shall be appointed by Act of the
Holders of a majority in principal amount of the Outstanding Securities
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 6.10, become the successor Trustee
and supersede the successor Trustee appointed by the Company. If no successor
Trustee shall have been so appointed by the Company or the Holders and accepted
appointment in the manner required by this Section and Section 6.10, any Holder
who has been a bona fide Holder for at least six months may, on behalf of
himself and all others similarly situated, petition any court of competent
jurisdiction for the appointment of a successor Trustee.

                                      -53-

<PAGE>

        (6) The Company shall give notice of each resignation and each removal
of the Trustee and each appointment of a successor Trustee to all Holders in the
manner provided in Section 1.6. Each notice shall include the name of the
successor Trustee and the address of its Corporate Trust Office.

        SECTION 6.10 ACCEPTANCE OF APPOINTMENT BY SUCCESSOR.

        Every successor Trustee appointed hereunder 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. 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.

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

        SECTION 6.11 MERGER, CONVERSION, CONSOLIDATION OR SUCCESSION TO
BUSINESS.

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

        SECTION 6.12 AUTHENTICATING AGENTS.

        The Trustee may, with the consent of the Company, appoint an
Authenticating Agent or Agents acceptable to the Company with respect to the
Securities which shall be authorized to act on behalf of the Trustee to
authenticate Securities issued upon original issue and upon registration of
transfer or redemption, exchange or substitution pursuant to this Indenture.
Securities authenticated by an Authenticating Agent shall be entitled to the
benefits of this Indenture and shall be valid and obligatory for all purposes as
if authenticated by the Trustee

                                      -54-

<PAGE>

hereunder, and every reference in this Indenture to the authentication and
delivery of Securities by the Trustee or the Trustee's certificate of
authentication 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 subject to acceptance by 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 and subject to
supervision or examination by government or other fiscal authority. If at any
time an Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section 6.12, such Authenticating Agent shall resign
immediately in the manner and with the effect specified in this Section 6.12.

        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 6.12, 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 6.12, the Trustee may appoint a successor
Authenticating Agent which shall be subject to acceptance by the Company. Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, 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 6.12.

        The Company agrees to pay to each Authenticating Agent from time to time
reasonable compensation for its services under this Section 6.12.

        If an Authenticating Agent is appointed with respect to the Securities
pursuant to this Section 6.12, the Securities may have endorsed thereon, in
addition to or in lieu of the Trustee's certification of authentication, an
alternative certificate of authentication in the following form:

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

                              __________________________________
                              as Trustee

                                      -55-

<PAGE>

                              By:_______________________________
                              As Authenticating Agent

                              By:_______________________________
                              Authorized Signatory

        SECTION 6.13 DISQUALIFICATION; CONFLICTING INTERESTS.

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

        SECTION 6.14 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).

                                   ARTICLE VII

              CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

        SECTION 7.1 COMPANY MAY CONSOLIDATE, ETC., ONLY ON CERTAIN TERMS.

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

        (1) the Person formed by such consolidation or into or with which the
Company is merged or the Person to which the properties and assets of the
Company are so conveyed, transferred, sold or leased shall be a corporation,
limited liability company, partnership or trust organized and validly existing
under the laws of the United States of America, any State thereof or the
District of Columbia and, if other than the Company, 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,
premium, if any, and interest on all of the Securities as applicable, and the
performance or observance of every covenant of this

                                      -56-

<PAGE>

Indenture on the part of the Company to be performed or observed [and shall have
provided for conversion rights in accordance with Article XII](53);

        (2) immediately after giving effect to such transaction, no Event of
Default, and no event that after notice or lapse of time or both, would become
an Event of Default, shall have occurred 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, together with any documents required under
Section 8.3.

        SECTION 7.2 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 all or
substantially all the properties and assets of the Company in accordance with
Section 7.1, the successor Person formed by such consolidation or into or with
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 VIII

                             SUPPLEMENTAL INDENTURES

         SECTION 8.1 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 in form reasonably
satisfactory to the Trustee hereto for any of the following purposes:

        (1) to evidence the succession of another Person to the Company and the
assumption by any such successor of the covenants and obligations of the Company
herein and in the Securities as permitted by Article VII of this Indenture; or

----------

        (53) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -57-

<PAGE>

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

        (3) to secure the Securities; or

        (4) [to make provision with respect to the conversion rights of Holders
pursuant to Section 12.11 or](54) to make provision with respect to the
repurchase rights of Holders pursuant to Section 14.5; or

        (5) to comply with the requirements of the Trust Indenture Act or the
rules and regulations of the Commission thereunder in order to effect or
maintain the qualification of this Indenture under the Trust Indenture Act, as
contemplated by this Indenture or otherwise; or

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

        (7) subject to Section 13.12, to make any change in Article XIII that
would limit or terminate the benefits available to any holder of Senior Debt
under such Article; or

        (8) to cure any ambiguity, to correct or supplement any provision herein
which may be inconsistent with any other provision herein or which is otherwise
defective, or to make any other provisions with respect to matters or questions
arising under this Indenture as the Company and the Trustee may deem necessary
or desirable, provided such action pursuant to this clause (8) shall not
adversely affect the interests of the Holders in any material respect.

        Upon Company Request, accompanied by a Board Resolution authorizing the
execution of any such supplemental indenture, and subject to and upon receipt by
the Trustee of the documents described in Section 8.3 hereof, the Trustee shall
join with the Company in the execution of any supplemental indenture authorized
or permitted by the terms of this Indenture and to make any further appropriate
agreements and stipulations which may be therein contained.

        SECTION 8.2 SUPPLEMENTAL INDENTURES WITH CONSENT OF HOLDERS.

        With either (i) the written consent of the Holders of not less than a
majority in principal amount of the Outstanding Securities, by the Act of said
Holders delivered to the Company and the Trustee, or (ii) by the adoption of a
resolution, at a meeting of Holders of the Outstanding Securities at which a
quorum is present, by the Holders of at least ______% in principal amount of the
Outstanding Securities represented at such meeting, 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 under this

----------

        (54) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -58-

<PAGE>

Indenture; provided, however, that no such supplemental indenture shall, without
the consent or affirmative vote of the Holder of each Outstanding Security
affected thereby,

        (1) change the Stated Maturity of the principal of, or any installment
of interest on, any Security, or reduce the principal amount of, or the premium,
if any, or the rate of interest payable thereon, or reduce the amount payable
upon a redemption or mandatory repurchase, or change the coin or currency of
payment of the principal of, premium, if any, or interest on any Security
(including any payment of the Redemption Price or Repurchase Price in respect of
such Security) or impair the right to institute suit for the enforcement of any
payment in respect of any Security on or after the Stated Maturity thereof (or,
in the case of redemption or any repurchase, on or after the Redemption Date or
Repurchase Date, as the case may be) [or, except as permitted by Section 12.11,
adversely affect the right of Holders to convert any Security as provided in
Article XII,](55) or modify the provisions of this Indenture with respect to the
subordination of the Securities in a manner adverse to the Holders; or

        (2) reduce the requirements of Section 9.4 for quorum or voting, or
reduce the percentage in principal amount of the Outstanding Securities 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 the obligation of the Company to maintain an office or agency
in the Borough of Manhattan, The City of New York, pursuant to Section 10.2; or

        (4) modify any of the provisions of this Section or Section 5.13, except
to increase any percentage contained herein or therein 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; or

        (5) modify the provisions of Article XIV in a manner adverse to the
Holders.

        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 8.3 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 and Officers' Certificate stating that
the execution of such supplemental indenture

----------

        (55) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -59-

<PAGE>

is authorized or permitted by this Indenture, and that such supplemental
indenture has been duly authorized, executed and delivered by the Company and
constitutes a valid and legally binding obligation of the Company enforceable
against the Company in accordance with its terms. 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 8.4 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
theretofore or thereafter authenticated and delivered hereunder appertaining
thereto shall be bound thereby.

        SECTION 8.5 REFERENCE IN SECURITIES TO SUPPLEMENTAL INDENTURES.

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

        SECTION 8.6 NOTICE OF SUPPLEMENTAL INDENTURES.

        Promptly after the execution by the Company and the Trustee of any
supplemental indenture pursuant to the provisions of Section 8.2, the Company
shall give notice to all Holders of such fact, setting forth in general terms
the substance of such supplemental indenture, in the manner provided in Section
1.6. Any failure of the Company to give such notice, or any defect therein,
shall not in any way impair or affect the validity of any such supplemental
indenture.

                                   ARTICLE IX

                               MEETINGS OF HOLDERS

             SECTION 9.1 PURPOSES FOR WHICH MEETINGS MAY BE CALLED.

        A meeting of Holders may be called at any time and from time to time
pursuant to this Article to make, give or take any request, demand,
authorization, direction, notice, consent, waiver or other action provided by
this Indenture to be made, given or taken by Holders.

                                      -60-

<PAGE>

        SECTION 9.2 CALL, NOTICE AND PLACE OF MEETINGS.

        (1) The Trustee may at any time call a meeting of Holders for any
purpose specified in Section 9.1, to be held at such time and at such place in
the Borough of Manhattan, The City of New York, as the Trustee shall determine.
Notice of every meeting of Holders, setting forth the time and the place of such
meeting and in general terms the action proposed to be taken at such meeting,
shall be given, in the manner provided in Section 1.6, not less than 21 nor more
than 180 days prior to the date fixed for the meeting.

        (2) In case at any time the Company, pursuant to a Board Resolution, or
the Holders of at least 10% in principal amount of the Outstanding Securities
shall have requested the Trustee to call a meeting of the Holders for any
purpose specified in Section 9.1, by written request setting forth in reasonable
detail the action proposed to be taken at the meeting, and the Trustee shall not
have mailed the notice of such meeting within 21 days after receipt of such
request or shall not thereafter proceed to cause the meeting to be held as
provided herein, then the Company or the Holders in the amount specified, as the
case may be, may determine the time and the place in the Borough of Manhattan,
The City of New York, for such meeting and may call such meeting for such
purposes by giving notice thereof as provided in paragraph (1) of this Section.

        SECTION 9.3 PERSONS ENTITLED TO VOTE AT MEETINGS.

        To be entitled to vote at any meeting of Holders, a Person shall be (i)
a Holder of one or more Outstanding Securities, or (ii) a Person appointed by an
instrument in writing as proxy for a Holder or Holders of one or more
Outstanding Securities by such Holder or Holders. The only Persons who shall be
entitled to be present or to speak at any meeting of Holders shall be the
Persons entitled to vote at such meeting and their counsel, any representatives
of the Trustee and its counsel and any representatives of the Company and its
counsel.

        SECTION 9.4 QUORUM; ACTION.

        The Persons entitled to vote a majority in principal amount of the
Outstanding Securities shall constitute a quorum. In the absence of a quorum
within 30 minutes of the time appointed for any such meeting, the meeting shall,
if convened at the request of Holders, be dissolved. In any other case, the
meeting may be adjourned for a period of not less than 10 days as determined by
the chairman of the meeting prior to the adjournment of such meeting. In the
absence of a quorum at any such adjourned meeting, such adjourned meeting may be
further adjourned for a period not less than 10 days as determined by the
chairman of the meeting prior to the adjournment of such adjourned meeting
(subject to repeated applications of this sentence). Notice of the reconvening
of any adjourned meeting shall be given as provided in Section 9.2(1), except
that such notice need be given only once not less than five days prior to the
date on which the meeting is scheduled to be reconvened. Notice of the
reconvening of an adjourned meeting shall state expressly the percentage of the
principal amount of the Outstanding Securities which shall constitute a quorum.

                                      -61-

<PAGE>

        Subject to the foregoing, at the reconvening of any meeting adjourned
for a lack of a quorum, the Persons entitled to vote 25% in principal amount of
the Outstanding Securities at the time shall constitute a quorum for the taking
of any action set forth in the notice of the original meeting.

        At a meeting or an adjourned meeting duly reconvened and at which a
quorum is present as aforesaid, any resolution and all matters (except as
limited by the proviso to Section 8.2 and except to the extent Section 10.12
requires a different vote) shall be effectively passed and decided if passed or
decided by the lesser of (i) the Holders of not less than a majority in
principal amount of Outstanding Securities and (ii) the Persons entitled to vote
not less than 66 2/3% in aggregate principal amount of Outstanding Securities
represented and entitled to vote at such meeting.

        Any resolution passed or decisions taken at any meeting of Holders duly
held in accordance with this Section shall be binding on all the Holders whether
or not present or represented at the meeting. The Trustee shall, in the name and
at the expense of the Company, notify all the Holders of any such resolutions or
decisions pursuant to Section 1.6.

        SECTION 9.5 DETERMINATION OF VOTING RIGHTS; CONDUCT AND ADJOURNMENT OF
MEETINGS.

        (1) The Trustee may make such reasonable regulations as it may deem
advisable for any meeting of Holders in regard to proof of the holding of
Securities and of the appointment of proxies and in regard to the appointment
and duties of inspectors of votes, the submission and examination of proxies,
certificates and other evidence of the right to vote, and such other matters
concerning the conduct of the meeting as it shall deem appropriate. Except as
otherwise permitted or required by any such regulations, the holding of
Securities shall be proved in the manner specified in Section 1.4 and the
appointment of any proxy shall be proved in the manner specified in Section 1.4
or by having the signature of the Person executing the proxy guaranteed by any
bank, broker or other eligible institution participating in a recognized
medallion signature guarantee program.

        (2) The Trustee shall, by an instrument in writing, appoint a temporary
chairman (which may be the Trustee) of the meeting, unless the meeting shall
have been called by the Company or by Holders as provided in Section 9.2(1), in
which case the Company or the Holders calling the meeting, as the case may be,
shall in like manner appoint a temporary chairman. A permanent chairman and a
permanent secretary of the meeting shall be elected by vote of the Persons
entitled to vote a majority in principal amount of the Outstanding Securities
represented at the meeting.

        (3) At any meeting, each Holder or proxy shall be entitled to one vote
for each U.S.$1,000 principal amount of Securities held or represented by him;
provided, however, that no vote shall be cast or counted at any meeting in
respect of any Security challenged as not

                                      -62-

<PAGE>

Outstanding and ruled by the chairman of the meeting to be not Outstanding. The
chairman of the meeting shall have no right to vote, except as a Holder or
proxy.

        (4) Any meeting of Holders duly called pursuant to Section 9.2 at which
a quorum is present may be adjourned from time to time by Persons entitled to
vote a majority in principal amount of the Outstanding Securities represented at
the meeting, and the meeting may be held as so adjourned without further notice.

        SECTION 9.6 COUNTING VOTES AND RECORDING ACTION OF MEETINGS.

        The vote upon any resolution submitted to any meeting of Holders shall
be by written ballots on which shall be subscribed the signatures of the Holders
or of their representatives by proxy and the principal amounts at Stated
Maturity and serial numbers of the Outstanding Securities held or represented by
them. The permanent chairman of the meeting shall appoint two inspectors of
votes who shall count all votes cast at the meeting for or against any
resolution and who shall make and file with the secretary of the meeting their
verified written reports in duplicate of all votes cast at the meeting. A
record, at least in duplicate, of the proceedings of each meeting of Holders
shall be prepared by the secretary of the meeting and there shall be attached to
said record the original reports of the inspectors of votes on any vote by
ballot taken thereat and affidavits by one or more Persons having knowledge of
the facts setting forth a copy of the notice of the meeting and showing that
said notice was given as provided in Section 9.2 and, if applicable, Section
9.4. Each copy shall be signed and verified by the affidavits of the permanent
chairman and secretary of the meeting and one such copy shall be delivered to
the Company and another to the Trustee to be preserved by the Trustee, the
latter to have attached thereto the ballots voted at the meeting. Any record so
signed and verified shall be conclusive evidence of the matters therein stated.

                                    ARTICLE X

                                    COVENANTS

            SECTION 10.1 PAYMENT OF PRINCIPAL, PREMIUM AND INTEREST.

        The Company covenants and agrees that it will duly and punctually pay
or cause to be paid the principal of and premium, if any, and interest on the
Securities in accordance with the terms of the Securities and this Indenture.
The Company will deposit or cause to be deposited with the Trustee, no later
than 10 a.m. New York time on the date of the Stated Maturity of any Security
or no later than the opening of business on the due date for any installment
of interest, all payments so due, which payments shall be in immediately
available funds on the date of such Stated Maturity or due date, as the case
may be.

                                      -63-

<PAGE>

        SECTION 10.2 MAINTENANCE OF OFFICES OR AGENCIES.

        The Company will maintain in the Borough of Manhattan, The City of New
York, an office or agency where the Securities may be surrendered for
registration of transfer or exchange or for presentation for payment or for
[conversion,](56) redemption or repurchase and where notices and demands to or
upon the Company in respect of the Securities 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 not designated or appointed
by the Trustee. If at any time the Company shall fail to maintain any such
required office or agency or shall fail to furnish the Trustee with the address
thereof, such presentations, surrenders, notices and demands may be made or
served at the Corporate Trust Office or the office or agency of the Trustee in
the Borough of Manhattan, The City of New York.

        The Company may at any time and from time to time vary or terminate the
appointment of any such agent or appoint any additional agents for any or all of
such purposes; provided, however, that until all of the Securities have been
delivered to the Trustee for cancellation, or moneys sufficient to pay the
principal of, premium, if any, and interest on the Securities have been made
available for payment and either paid or returned to the Company pursuant to the
provisions of Section 10.3, the Company will maintain in the Borough of
Manhattan, The City of New York, an office or agency where Securities may be
presented or surrendered for payment [and conversion](57), which shall initially
be ___________________, where Securities may be surrendered for registration of
transfer or exchange and where notices and demands to or upon the Company in
respect of the Securities and this Indenture may be served. The Company will
give prompt written notice to the Trustee, and notice to the Holders in
accordance with Section 1.6, of the appointment or termination of any such
agents and of the location and any change in the location of any such office or
agency.

        The Company hereby initially designates the Trustee as Paying Agent,
Security Registrar [and Conversion Agent](58), and each of the Corporate Trust
Office of the Trustee and the office or agency of the Trustee in the Borough of
Manhattan, The City of New York, located at______,
___________________________attention:___________________________________________
as one such office or agency of the Company for each of the aforesaid purposes.

          SECTION 10.3 MONEY FOR SECURITY PAYMENTS TO BE HELD IN TRUST.

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

----------

        (56) INSERT IF SECURITIES ARE CONVERTIBLE

        (57) INSERT IF SECURITIES ARE CONVERTIBLE

        (58) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -64-

<PAGE>

        Whenever the Company shall have one or more Paying Agents, it will,
no later than 10 a.m. New York time on each due date of the principal of,
premium, if any, or interest on any Securities, deposit with the Trustee a
sum in funds immediately payable on the payment date sufficient to pay the
principal, premium, if any, or interest so becoming due, such sum to be held
for the benefit of the Persons entitled to such principal, premium, if any,
or interest, and (unless such Paying Agent is the Trustee) the Company will
promptly notify the Trustee of any failure so to act.

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

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

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

        (3) at any time during the continuance of any such default, upon the
written request of the Trustee, forthwith pay to the Trustee all sums so held by
such Paying Agent.

        Anything in this Section 10.3 to the contrary notwithstanding, 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, premium, if any,
or interest on any Security and remaining unclaimed for two years after such
principal, premium, if any, 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. The Company shall not be liable for any interest on the sums paid to it
pursuant to this paragraph and shall not be regarded as a trustee of such money.

                                      -65-

<PAGE>

        SECTION 10.4 EXISTENCE.

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

        SECTION 10.5 PAYMENT OF TAXES AND OTHER CLAIMS.

        The Company will pay or discharge, or cause to be paid or discharged,
before the same may become delinquent, (i) all taxes, assessments and
governmental charges levied or imposed upon the Company or any Significant
Subsidiary or upon the income, profits or property of the Company or any
Significant Subsidiary, (ii) all claims for labor, materials and supplies which,
if unpaid, might by law become a lien or charge upon the property of the Company
or any Significant Subsidiary, and (iii) all stamps and other duties, if any,
which may be imposed by the United States or any political subdivision thereof
or therein in connection with the issuance, transfer, exchange [or
conversion](59) of any Securities or with respect to this Indenture; provided,
however, that, in the case of clauses (i) and (ii), the Company shall not be
required to pay or discharge or cause to be paid or discharged any such tax,
assessment, charge or claim (A) if the failure to do so will not, in the
aggregate, have a material adverse impact on the Company, or (B) if the amount,
applicability or validity is being contested in good faith by appropriate
proceedings.

        [SECTION 10.6 REGISTRATION AND LISTING.

        The Company (i) will effect all registrations with, and obtain all
approvals by, all governmental authorities that may be necessary under any
United States Federal or state law (including the Securities Act, the Exchange
Act and state securities and Blue Sky laws) before the shares of Common Stock
issuable upon conversion of Securities are issued and delivered, and qualified
or listed as contemplated by clause (ii); and (ii) will qualify the shares of
Common Stock required to be issued and delivered upon conversion of Securities,
prior to such issuance or delivery, for quotation on the Nasdaq National Market
or, if the Common Stock is not then quoted on the Nasdaq National Market, list
the Common Stock on each national securities exchange or quotation system on
which outstanding Common Stock is listed or quoted at the time of such
delivery.](60)

----------

        (59) INSERT IF SECURITIES ARE CONVERTIBLE

        (60) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -66-

<PAGE>

        SECTION 10.7 STATEMENT BY OFFICERS AS TO DEFAULT.

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

        The Company will deliver to the Trustee, forthwith upon becoming aware
of any default or any Event of Default under the Indenture, an Officers'
Certificate specifying with particularity such default or Event of Default and
further stating what action the Company has taken, is taking or proposes to take
with respect thereto. 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.

        Any notice required to be given under this Section 10.7 shall be
delivered to the Trustee at its Corporate Trust Office.

        SECTION 10.8 WAIVER OF CERTAIN COVENANTS.

        The Company may omit in any particular instance to comply with any
covenant or condition set forth in Sections 10.4 (other than with respect to the
existence of the Company (subject to Article VII)) and 10.5, inclusive (other
than a covenant or condition which under Article VIII cannot be modified or
amended without the consent of the Holder of each Outstanding Security
affected), if before the time for such compliance the Holders shall, through the
written consent of, or the adoption of a resolution at a meeting of Holders of
the Outstanding Securities at which a quorum is present by, not less than a
majority in principal amount of the Outstanding Securities, either waive such
compliance in such instance or generally waive compliance with such covenant or
condition, but no such waiver shall extend to or affect such covenant or
condition except to the extent so expressly waived, and, until such waiver shall
become effective, the obligations of the Company and the duties of the Trustee
or any Paying [or Conversion](61) Agent in respect of any such covenant or
condition shall remain in full force and effect.

                                   ARTICLE XI

                            REDEMPTION OF SECURITIES

        SECTION 11.1 RIGHT OF REDEMPTION.

        The Securities may be redeemed in accordance with the provisions of the
form of Securities set forth in Section 2.2.

----------

        (61) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -67-

<PAGE>

        SECTION 11.2 APPLICABILITY OF ARTICLE.

        Redemption of Securities at the election of the Company or otherwise, as
permitted or required by any provision of the Securities or this Indenture,
shall be made in accordance with such provision and this Article XI.

        SECTION 11.3 ELECTION TO REDEEM; NOTICE TO TRUSTEE.

        The election of the Company to redeem any Securities shall be evidenced
by a Board Resolution. In case of any redemption at the election of the Company
of any of the Securities, 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 in writing of such Redemption
Date.

        SECTION 11.4 SELECTION BY TRUSTEE OF SECURITIES TO BE REDEEMED.

        If less than all the Securities are to be redeemed, the particular
Securities to be redeemed shall be selected by the Trustee within three Business
Days after it receives the notice described in 11.3, from the Outstanding
Securities not previously called for redemption, by such method as the Trustee
may deem fair and appropriate.

        [If any Security selected for partial redemption is converted in part
before termination of the conversion right with respect to the portion of the
Security so selected, the converted portion of such Security shall be deemed (so
far as may be) to be the portion selected for redemption. Securities which have
been converted during a selection of Securities to be redeemed may be treated by
the Trustee as Outstanding for the purpose of such selection.](62) The Trustee
shall promptly notify the Company and each Security Registrar in writing of the
Securities selected for redemption and, in the case of any Securities selected
for partial redemption, the principal amount and certificate numbers thereof to
be redeemed.

        For all purposes of this Indenture, unless the context otherwise
requires, all provisions relating to the redemption of Securities shall relate,
in the case of any

        Securities redeemed or to be redeemed only in part, to the portion of
the principal amount of such Securities which has been or is to be redeemed.

----------

        (62) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -68-

<PAGE>

        SECTION 11.5 NOTICE OF REDEMPTION.

        Notice of redemption shall be given in the manner provided in Section
1.6 to the Holders to be redeemed not less than 30 nor more than 60 days prior
to the Redemption Date, and such notice shall be irrevocable.

        All notices of redemption shall include the CUSIP number and state:

        (1) the Redemption Date;

        (2) the Redemption Price, and accrued interest, if any, to the
Redemption Date;

        (3) if less than all Outstanding Securities are to be redeemed, the
aggregate principal amount of Securities to be redeemed and the aggregate
principal amount of Securities which will be outstanding after such partial
redemption;

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

        [(5) the Conversion Rate, the date on which the right to convert the
Securities to be redeemed will terminate and the places where such Securities
may be surrendered for conversion;](63) and

        (6) the place or places where such Securities are to be surrendered for
payment of the Redemption Price and accrued interest, if any, to the Redemption
Date.

        In case of a partial redemption, the notice shall specify the serial and
CUSIP numbers (if any) and the portions thereof called for redemption and that
transfers and exchanges may occur on or prior to the Redemption Date.

        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 written request, by
the Trustee in the name of and at the expense of the Company. Notice of
redemption of Securities to be redeemed at the election of the Company received
by the Trustee shall be given by the Trustee to each Paying Agent in the name of
and at the expense of the Company. Notice of redemption of the Securities to be
redeemed at the election of the Company shall also be given to one or more
nationally-recognized reporting institutions such as Bloomberg.

        SECTION 11.6 DEPOSIT OF REDEMPTION PRICE.

        Prior to 10 a.m. New York time on any Redemption Date, the Company
shall deposit with the Trustee (or, if the Company is acting as its own
Paying Agent, segregate and hold in trust as provided in

----------

        (63) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -69-

<PAGE>

Section 10.3) an amount of money (which shall be in immediately available funds
on such Redemption Date) sufficient to pay the Redemption Price of, and (except
if the Redemption Date shall be an Interest Payment Date) accrued interest to
the Redemption Date on, all the Securities which are to be redeemed on that date
[other than any Securities called for redemption on that date which have been
converted prior to the date of such deposit](64).

        [If any Security called for redemption is converted, any money deposited
with the Trustee or so segregated and held in trust for the redemption of such
Security shall (subject to any right of the Holder of such Security or any
Predecessor Security to receive interest as provided in the last paragraph of
Section 3.7) be paid to the Company on Company Request or, if then held by the
Company, shall be discharged from such trust.](65)

        SECTION 11.7 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, including accrued
interest) such Securities shall cease to bear interest. Upon surrender of any
Security for redemption in accordance with said notice, such Security shall be
paid by the Company at the Redemption Price together with accrued and unpaid
interest to the Redemption Date; provided, however, that installments of
interest on Securities whose Stated Maturity is on or prior to the Redemption
Date shall be payable to the Holders of such Securities, or one or more
Predecessor Securities, registered as such on the relevant Record Date 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 amount of, premium, if any, and,
to the extent permitted by applicable law, accrued interest on such Security
shall, until paid, bear interest from the Redemption Date at a rate of _____%
per annum [and such Security shall remain convertible](66) until the Redemption
Price of such Security (or portion thereof, as the case may be) shall have been
paid or duly provided for.

        Any Security which is to be redeemed only in part shall be surrendered
at the Corporate Trust Office or an office or agency of the Company designated
for that purpose pursuant to Section 10.2 (with, if the Company or the Trustee
so requires, due endorsement by, or a written instrument of transfer in form
satisfactory to the Company and the Trustee duly executed by, the Holder thereof
or his attorney duly authorized in writing), and the Company shall execute, and
the Trustee shall authenticate and make available for delivery to the Holder of
such Security

----------

        (64) INSERT IF SECURITIES ARE CONVERTIBLE

        (65) INSERT IF SECURITIES ARE CONVERTIBLE

        (66) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -70-

<PAGE>

without service charge, a new Security or Securities, of any authorized
denomination as requested by such Holder, in aggregate principal amount equal to
and in exchange for the unredeemed portion of the principal of the Security so
surrendered.

        [SECTION 11.8 CONVERSION ARRANGEMENT ON CALL FOR REDEMPTION.

        In connection with any redemption of Securities, the Company may
arrange for the purchase and conversion of any Securities by an agreement
with one or more investment bankers or other purchasers (the "Purchasers") to
purchase such Securities by paying to the Trustee in trust for the Holders,
on or before the Redemption Date, an amount not less than the applicable
Redemption Price, together with interest accrued and unpaid to the Redemption
Date, of such Securities. Notwithstanding anything to the contrary contained
in this Article XI, the obligation of the Company to pay the Redemption
Price, together with interest accrued and unpaid to the Redemption Date,
shall be deemed to be satisfied and discharged to the extent such amount is
so paid by such Purchasers. If such an agreement is entered into (a copy of
which shall be filed with the Trustee prior to the close of business on the
Business Day immediately prior to the Redemption Date), any Securities called
for redemption that are not duly surrendered for conversion by the Holders
thereof may, at the option of the Company, be deemed, to the fullest extent
permitted by law, and consistent with any agreement or agreements with such
Purchasers, to be acquired by such Purchasers from such Holders and
(notwithstanding anything to the contrary contained in Article XII)
surrendered by such Purchasers for conversion, all as of immediately prior to
the close of business on the Redemption Date (and the right to convert any
such Securities shall be extended through such time), subject to payment of
the above amount as aforesaid. At the direction of the Company, the Trustee
shall hold and dispose of any such amount paid to it by the Purchasers to the
Holders in the same manner as it would monies deposited with it by the
Company for the redemption of Securities. Without the Trustee's prior written
consent, no arrangement between the Company and such Purchasers for the
purchase and conversion of any Securities shall increase or otherwise affect
any of the powers, duties, responsibilities or obligations of the Trustee as
set forth in this Indenture, and the Company agrees to indemnify the Trustee
from, and hold it harmless against, any and all loss, liability, claim,
damage or expense arising out of or in connection with any such arrangement
for the purchase and conversion of any Securities between the Company and
such Purchasers, including the costs and expenses, including reasonable legal
fees, incurred by the Trustee in the defense of any claim or liability
arising out of or in connection with the exercise or performance of any of
its powers, duties, responsibilities or obligations under this Indenture.](67)

----------

        (67) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -71-

<PAGE>

                                  [ARTICLE XII

                            CONVERSION OF SECURITIES

             SECTION 12.1 CONVERSION PRIVILEGE AND CONVERSION RATE.

        Subject to and upon compliance with the provisions of this Article, at
the option of the Holder thereof, any Security may be converted into fully paid
and nonassessable shares (calculated as to each conversion to the nearest
1/100th of a share) of Common Stock of the Company at the Conversion Rate,
determined as hereinafter provided, in effect at the time of conversion. Such
conversion right shall commence upon the original issuance date of the
Securities and expire at the close of business on the date of Maturity, subject,
in the case of conversion of any Global Security, to any Applicable Procedures.
In case a Security or portion thereof is called for redemption at the election
of the Company or the Holder thereof exercises his right to require the Company
to repurchase the Security, such conversion right in respect of the Security, or
portion thereof so called, shall expire at the close of business on the Business
Day immediately preceding the Redemption Date or the Repurchase Date, as the
case may be, unless the Company defaults in making the payment due upon
redemption or repurchase, as the case may be (in each case subject as aforesaid
to any Applicable Procedures with respect to any Global Security).

        The rate at which shares of Common Stock shall be delivered upon
conversion (herein called the "Conversion Rate") shall be initially ______
shares of Common Stock for each U.S. $1,000 principal amount of Securities. The
Conversion Rate shall be adjusted in certain instances as provided in this
Article XII.

        SECTION 12.2 EXERCISE OF CONVERSION PRIVILEGE.

        In order to exercise the conversion privilege, the Holder of any
Security to be converted shall surrender such Security, duly endorsed in blank,
at any office or agency of the Company maintained for that purpose pursuant to
Section 10.2, accompanied by a duly signed conversion notice substantially in
the form set forth in Section 2.4 stating that the Holder elects to convert such
Security or, if less than the entire principal amount thereof is to be
converted, the portion thereof to be converted. Each Security surrendered for
conversion (in whole or in part) during the Record Date Period shall (except in
the case of any Security or portion thereof which has been called for redemption
on a Redemption Date, or is repurchasable on a Repurchase Date, occurring, in
either case, within such Record Date Period and, as a result, the right to
convert would terminate in such period) be accompanied by payment in New York
Clearing House funds or other funds acceptable to the Company of an amount equal
to the interest payable on such Interest Payment Date on the principal amount of
such Security (or part thereof, as the case may be) being surrendered for
conversion. The interest so payable on such Interest Payment Date with respect
to any Security (or portion thereof, if applicable) which is surrendered for
conversion during the Record Date Period shall be paid to the Holder of such
Security as of such Regular Record Date in an amount equal to the interest that
would have been payable on such Security if

                                      -72-

<PAGE>

such Security had been converted as of the close of business on such Interest
Payment Date. Interest payable in respect of any Security surrendered for
conversion on or after an Interest Payment Date shall be paid to the Holder of
such Security as of the next preceding Regular Record Date, notwithstanding the
exercise of the right of conversion. Except as provided in this paragraph and
subject to the last paragraph of Section 3.7, no cash payment or adjustment
shall be made upon any conversion on account of any interest accrued from the
Interest Payment Date next preceding the conversion date, in respect of any
Security (or part thereof, as the case may be) surrendered for conversion, or on
account of any dividends on the Common Stock issued upon conversion. The
Company's delivery to the Holder of the number of shares of Common Stock (and
cash in lieu of fractions thereof, as provided in this Indenture) into which a
Security is convertible will be deemed to satisfy the Company's obligation to
pay the principal amount of the Security.

        Securities shall be deemed to have been converted immediately prior to
the close of business on the day of surrender of such Securities for conversion
in accordance with the foregoing provisions, and at such time the rights of the
Holders of such Securities as Holders shall cease, and the Person or Persons
entitled to receive the Common Stock issuable upon conversion shall be treated
for all purposes as the record holder or holders of such Common Stock at such
time. As promptly as practicable on or after the conversion date, the Company
shall issue and deliver to the Trustee, for delivery to the Holder, a
certificate or certificates for the number of full shares of Common Stock
issuable upon conversion, together with payment in lieu of any fraction of a
share, as provided in Section 12.3.

        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 the Holder thereof, at the expense of the Company, a new Security or
Securities of authorized denominations in an aggregate principal amount equal to
the unconverted portion of the principal amount of such Security. A Security may
be converted in part, but only if the principal amount of such Security to be
converted is an integral multiple of U.S.$1,000 and the principal amount of such
security to remain Outstanding after such conversion is an integral multiple of
$1,000.

        SECTION 12.3 FRACTIONS OF SHARES.

        No fractional shares of Common Stock shall be issued upon conversion
of any Security or Securities. 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 thereof shall be computed on the
basis of the aggregate principal amount of the Securities (or specified
portions thereof) so surrendered. Instead of any fractional share of Common
Stock which would otherwise be issuable upon conversion of any Security or
Securities (or specified portions thereof), the Company shall calculate and
pay a cash adjustment in respect of such fraction (calculated to the nearest
1/100th of a share) in an amount equal to the same fraction of the Closing
Price Per Share at the close of business on the day of conversion.

                                      -73-

<PAGE>

        SECTION 12.4 ADJUSTMENT OF CONVERSION RATE.

        The Conversion Rate shall be subject to adjustments from time to time as
follows:

        (1) In case the Company shall pay or make a dividend or other
distribution on shares of any class of capital stock of the Company payable in
shares of Common Stock, the Conversion Rate in effect at the opening of business
on the day following the date fixed for the determination of stockholders
entitled to receive such dividend or other distribution shall be increased by
dividing such Conversion Rate by a fraction of which the numerator shall be the
number of shares of Common Stock outstanding at the close of business on the
date fixed for such determination and the denominator shall be the sum of such
number of shares and the total number of shares constituting such dividend or
other distribution, such increase to become effective immediately after the
opening of business on the day following the date fixed for such determination.
If, after any such date fixed for determination, any dividend or distribution is
not in fact paid, the Conversion Rate shall be immediately readjusted, effective
as of the date the Board of Directors determines not to pay such dividend or
distribution, to the Conversion Rate that would have been in effect if such
determination date had not been fixed. For the purposes of this paragraph (1),
the number of shares of Common Stock at any time outstanding shall not include
shares held in the treasury of the Company but shall include shares issuable in
respect of scrip certificates issued in lieu of fractions of shares of Common
Stock. The Company will not pay any dividend or make any distribution on shares
of Common Stock held in the treasury of the Company.

        (2) In case the Company shall issue rights, options or warrants to all
holders of its Common Stock entitling them to subscribe for or purchase shares
of Common Stock at a price per share less than the current market price per
share (determined as provided in paragraph (8) of this Section 12.4) of the
Common Stock on the date fixed for the determination of stockholders entitled to
receive such rights, options or warrants (other than any rights, options or
warrants that by their terms will also be issued to any Holder upon conversion
of a Security into shares of Common Stock without any action required by the
Company or any other Person), the Conversion Rate in effect at the opening of
business on the day following the date fixed for such determination shall be
increased by dividing such Conversion Rate by a fraction of which the numerator
shall be the number of shares of Common Stock outstanding at the close of
business on the date fixed for such determination plus the number of shares of
Common Stock which the aggregate of the offering price of the total number of
shares of Common Stock so offered for subscription or purchase would purchase at
such current market price and the denominator shall be the number of shares of
Common Stock outstanding at the close of business on the date fixed for such
determination plus the number of shares of Common Stock so offered for
subscription or purchase, such increase to become effective immediately after
the opening of business on the day following the date fixed for such
determination. If, after any such date fixed for determination, any such rights,
options or warrants are not in fact issued, or are not exercised prior to the
expiration thereof, the Conversion Rate shall be immediately readjusted,
effective as of the date such rights, options or warrants expire, or the date
the Board of Directors determines not to issue such rights, options or warrants,
to the Conversion Rate that would have been in

                                      -74-

<PAGE>

effect if the unexercised rights, options or warrants had never been granted or
such determination date had not been fixed, as the case may be. For the purposes
of this paragraph (2), the number of shares of Common Stock at any time
outstanding shall not include shares held in the treasury of the Company but
shall include shares issuable in respect of scrip certificates issued in lieu of
fractions of shares of Common Stock. The Company will not issue any rights,
options or warrants in respect of shares of Common Stock held in the treasury of
the Company.

        (3) In case the outstanding shares of Common Stock shall be subdivided
into a greater number of shares of Common Stock, the Conversion Rate in effect
at the opening of business on the day following the day upon which such
subdivision becomes effective shall be proportionately increased, and,
conversely, in case the outstanding shares of Common Stock shall be combined
into a smaller number of shares of Common Stock, the Conversion Rate in effect
at the opening of business on the day following the day upon which such
subdivision or combination becomes effective shall be proportionately reduced,
such increase or reduction, as the case may be, to become effective immediately
after the opening of business on the day following the day upon which such
subdivision or combination becomes effective.

        (4) In case the Company shall, by dividend or otherwise, distribute to
all holders of its Common Stock evidences of its indebtedness, shares of any
class of capital stock or other property (including cash or assets or
securities, but excluding (i) any rights, options or warrants referred to in
paragraph (2) of this Section, (ii) any dividend or distribution paid
exclusively in cash, (iii) any dividend or distribution referred to in paragraph
(1) of this Section and (iv) any mergers or consolidations to which Section
12.11 applies), the Conversion Rate shall be adjusted so that the same shall
equal the rate determined by dividing the Conversion Rate in effect immediately
prior to the close of business on the date fixed for the determination of
stockholders entitled to receive such distribution by a fraction of which the
numerator shall be the current market price per share (determined as provided in
paragraph (8) of this Section 12.4) of the Common Stock on the date fixed for
such determination less the then fair market value (as determined by the Board
of Directors, whose determination shall be conclusive and described in a Board
Resolution filed with the Trustee) of the portion of the assets, shares or
evidences of indebtedness so distributed applicable to one share of Common Stock
and the denominator shall be such current market price per share of the Common
Stock, such adjustment to become effective immediately prior to the opening of
business on the day following the date fixed for the determination of
stockholders entitled to receive such distribution. If, after any such date
fixed for determination, any such distribution is not in fact made, the
Conversion Rate shall be immediately readjusted, effective as of the date that
the Board of Directors determines not to make such distribution, to the
Conversion Rate that would have been in effect if such determination date had
not been fixed.

        (5) In case the Company shall, by dividend or otherwise, distribute to
all holders of its Common Stock cash (excluding any cash that is distributed as
part of a distribution referred to in paragraph (4) of this Section or cash
distributed upon a merger or consolidation to which Section 12.11 applies) in an
aggregate amount that, combined together with (I) the aggregate amount of any
other cash distributions to all holders of its Common Stock made exclusively in

                                      -75-

<PAGE>

cash within the 365-day period preceding the date of payment of such
distribution and in respect of which no adjustment pursuant to this paragraph
(5) has been made and (II) the aggregate of any cash plus the fair market value
(as determined by the Board of Directors, whose determination shall be
conclusive and described in a Board Resolution) of consideration payable in
respect of any tender offer by the Company or any of its Subsidiaries for all or
any portion of the Common Stock concluded within the 365-day period preceding
the date of payment of such distribution and in respect of which no adjustment
pursuant to paragraph (6) of this Section 12.4 has been made (the "combined cash
and tender amount") exceeds 10% of the product of the current market price per
share (determined as provided in paragraph (8) of this Section 12.4) of the
Common Stock on the date for the determination of holders of shares of Common
Stock entitled to receive such distribution times the number of shares of Common
Stock outstanding on such date (the "aggregate current market price"), then, and
in each such case, immediately after the close of business on such date for
determination, the Conversion Rate shall be adjusted so that the same shall
equal the rate determined by dividing the Conversion Rate in effect immediately
prior to the close of business on the date fixed for determination of the
stockholders entitled to receive such distribution by a fraction (i) the
numerator of which shall be equal to the current market price per share
(determined as provided in paragraph (8) of this Section) of the Common Stock on
the date fixed for such determination less an amount equal to the quotient of
(x) the excess of such combined cash and tender amount over such aggregate
current market price divided by (y) the number of shares of Common Stock
outstanding on such date for determination and (ii) the denominator of which
shall be equal to the current market price per share (determined as provided in
paragraph (8) of this Section 12.4) of the Common Stock on such date fixed for
determination.

        (6) In case a tender offer made by the Company or any Subsidiary for all
or any portion of the Common Stock shall expire and such tender offer (as
amended upon the expiration thereof) shall require the payment to stockholders
(based on the acceptance (up to any maximum specified in the terms of the tender
offer) of Purchased Shares (as defined below)) of an aggregate consideration
having a fair market value (as determined by the Board of Directors, whose
determination shall be conclusive and described in a Board Resolution) that
combined together with (I) the aggregate of the cash plus the fair market value
(as determined by the Board of Directors, whose determination shall be
conclusive and described in a Board Resolution), as of the expiration of such
tender offer, of consideration payable in respect of any other tender offer by
the Company or any Subsidiary for all or any portion of the Common Stock
expiring within the 365-day period preceding the expiration of such tender offer
and in respect of which no adjustment pursuant to this paragraph (6) has been
made and (II) the aggregate amount of any cash distributions to all holders of
the Common Stock within the 365-day period preceding the expiration of such
tender offer and in respect of which no adjustment pursuant to paragraph (5) of
this Section has been made (the "combined tender and cash amount") exceeds ___%
of the product of the current market price per share of the Common Stock
(determined as provided in paragraph (8) of this Section 12.4) as of the last
time (the "Expiration Time") tenders could have been made pursuant to such
tender offer (as it may be amended) times the number of shares of Common Stock
outstanding (including any tendered shares) as of the Expiration Time, then, and
in each such case, immediately prior to the opening of business on the day after
the date of the

                                      -76-

<PAGE>

Expiration Time, the Conversion Rate shall be adjusted so that the same shall
equal the rate determined by dividing the Conversion Rate immediately prior to
close of business on the date of the Expiration Time by a fraction (i) the
numerator of which shall be equal to (A) the product of (I) the current market
price per share of the Common Stock (determined as provided in paragraph (8) of
this Section 12.4) on the date of the Expiration Time multiplied by (II) the
number of shares of Common Stock outstanding (including any tendered shares) on
the Expiration Time less (B) the combined tender and cash amount, and (ii) the
denominator of which shall be equal to the product of (A) the current market
price per share of the Common Stock (determined as provided in paragraph (8) of
this Section 12.4) as of the Expiration Time multiplied by (B) the number of
shares of Common Stock outstanding (including any tendered shares) as of the
Expiration Time less the number of all shares validly tendered and not withdrawn
as of the Expiration Time (the shares deemed so accepted up to any such maximum,
being referred to as the "Purchased Shares").

        (7) The reclassification of Common Stock into securities other than
Common Stock (other than any reclassification upon a consolidation or merger to
which Section 12.11 applies) shall be deemed to involve (a) a distribution of
such securities other than Common Stock to all holders of Common Stock (and the
effective date of such reclassification shall be deemed to be "the date fixed
for the determination of stockholders entitled to receive such distribution" and
"the date fixed for such determination" within the meaning of paragraph (4) of
this Section), and (b) a subdivision or combination, as the case may be, of the
number of shares of Common Stock outstanding immediately prior to such
reclassification into the number of shares of Common Stock outstanding
immediately thereafter (and the effective date of such reclassification shall be
deemed to be "the day upon which such subdivision becomes effective" or "the day
upon which such combination becomes effective", as the case may be, and "the day
upon which such subdivision or combination becomes effective" within the meaning
of paragraph (3) of this Section 12.4).

        (8) For the purpose of any computation under paragraphs (2), (4), (5) or
(6) of this Section 12.4, the current market price per share of Common Stock on
any date shall be calculated by the Company and be deemed to be the average of
the daily Closing Prices Per Share for the five consecutive Trading Days
selected by the Company commencing not more than 10 Trading Days before, and
ending not later than the earlier of the day in question and the day before the
"ex" date with respect to the issuance or distribution requiring such
computation. For purposes of this paragraph, the term "'ex' date", when used
with respect to any issuance or distribution, means the first date on which the
Common Stock trades the regular way in the applicable securities market or on
the applicable securities exchange without the right to receive such issuance or
distribution.

        (9) No adjustment in the Conversion Rate shall be required unless such
adjustment (plus any adjustments not previously made by reason of this paragraph
(9)) would require an increase or decrease of at least one percent in such rate;
provided, however, that any adjustments which by reason of this paragraph (9)
are not required to be made shall be carried forward and

                                      -77-

<PAGE>

taken into account in any subsequent adjustment. All calculations under this
Article shall be made to the nearest cent or to the nearest one-hundredth of a
share, as the case may be.

        (10) The Company may in its sole discretion make such increases in the
Conversion Rate, for the remaining term of the Securities or any shorter term,
in addition to those required by paragraphs (1), (2), (3), (4), (5) and (6) of
this Section 12.4, as it considers to be advisable in order to avoid or diminish
any income tax liability to any holders of shares of Common Stock resulting from
any dividend or distribution of stock or issuance of rights or warrants to
purchase or subscribe for stock or from any event treated as such for income tax
purposes. The Company shall have the power to resolve any ambiguity or correct
any error in this paragraph (10) and its actions in so doing shall, absent
manifest error, be final and conclusive.

        (11) Notwithstanding the foregoing provisions of this Section, no
adjustment of the Conversion Rate shall be required to be made (a) upon the
issuance of shares of Common Stock pursuant to any present or future plan for
the reinvestment of dividends or (b) because of a tender or exchange offer of
the character described in Rule 13e-4(h)(5) under the Exchange Act or any
successor rule thereto.

        (12) To the extent permitted by applicable law, the Company from time to
time may increase the Conversion Rate by any amount for any period of time if
the period is at least twenty (20) days and the Board of Directors shall have
made a determination that such increase would be in the best interests of the
Company, which determination shall be conclusive; provided, however, that no
such increase shall be taken into account for purposes of determining whether
the Closing Price Per Share of the Common Stock equals or exceeds ____% of the
Conversion Price in connection with an event which would otherwise be a Change
of Control pursuant to Section 14.4. Whenever the Conversion Rate is increased
pursuant to the preceding sentence, the Company shall give notice of the
increase to the Holders in the manner provided in Section 1.6 at least fifteen
(15) days prior to the date the increased Conversion Rate takes effect, and such
notice shall state the increased Conversion Rate and the period during which it
will be in effect.

        SECTION 12.5 NOTICE OF ADJUSTMENTS OF CONVERSION RATE.

        Whenever the Conversion Rate is adjusted as herein provided:

        (1) the Company shall compute the adjusted Conversion Rate in accordance
with Section 12.4 and shall prepare a certificate signed by the Chief Financial
Officer of the Company setting forth the adjusted Conversion Rate and showing in
reasonable detail the facts upon which such adjustment is based, and such
certificate shall promptly be filed with the Trustee and with each Conversion
Agent; and

        (2) upon each such adjustment, a notice stating that the Conversion Rate
has been adjusted and setting forth the adjusted Conversion Rate shall be
required, and as soon as practicable after it is required, such notice shall be
provided by the Company to all Holders in accordance with Section 1.6.

                                      -78-

<PAGE>

        Neither the Trustee nor any Conversion Agent shall be under any duty or
responsibility with respect to any such certificate or the information and
calculations contained therein, except to exhibit the same to any Holder
desiring inspection thereof at its office during normal business hours, and
shall not be deemed to have knowledge of any adjustment in the Conversion Rate
unless and until a Responsible Officer of the Trustee shall have received such a
certificate. Until a Responsible Officer of the Trustee receives such a
certificate, the Trustee and each Conversion Agent may assume without inquiry
that the last Conversion Rate of which the Trustee has knowledge of remains in
effect.

        SECTION 12.6 NOTICE OF CERTAIN CORPORATE ACTION.

        In case:

        (1) the Company shall declare a dividend (or any other distribution) on
its Common Stock payable (i) otherwise than exclusively in cash or (ii)
exclusively in cash in an amount that would require any adjustment pursuant to
Section 12.4; 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;
or

        (3) of any reclassification of the Common Stock, or of any
consolidation, merger or share exchange to which the Company is a party and for
which approval of any stockholders of the Company is required, or of the
conveyance, sale, transfer or lease 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 at each office or
agency maintained for the purpose of conversion of Securities pursuant to
Section 10.2, and shall cause to be provided to all Holders in accordance with
Section 1.6, at least 20 days (or 10 days in any case specified in clause (1) or
(2) above) prior to the applicable record or effective date hereinafter
specified, a notice stating (x) the date on which a record is to be taken for
the purpose of such dividend, distribution, rights, 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 (y) the date on which such reclassification,
consolidation, merger, conveyance, transfer, sale, lease, 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, conveyance,
transfer, sale, lease, dissolution, liquidation or winding up. Neither the
failure to give such notice or the notice referred to in the following paragraph
nor any defect therein shall affect the legality or validity of the proceedings
described in clauses (1) through (4) of this Section 12.6. If at the time the
Trustee shall not be the Conversion Agent, a copy of such notice shall also
forthwith be filed by

                                      -79-

<PAGE>

the Company with the Trustee. The Company shall cause to be filed at each office
or agency maintained for the purpose of conversion of Securities pursuant to
Section 10.2, and shall cause to be provided to all Holders in accordance with
Section 1.6, notice of any tender offer by the Company or any Subsidiary for all
or any portion of the Common Stock at or about the time that such notice of
tender offer is provided to the public generally.

        SECTION 12.7 COMPANY TO RESERVE 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 then issuable upon the conversion of all Outstanding Securities.

        SECTION 12.8 TAXES ON CONVERSIONS.

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

        SECTION 12.9 COVENANT AS TO COMMON STOCK.

        The Company agrees that all shares of Common Stock which may be
delivered upon conversion of Securities, upon such delivery, will have been duly
authorized and validly issued and will be fully paid and nonassessable and,
except as provided in Section 12.8, the Company will pay all taxes, liens and
charges with respect to the issue thereof.

        SECTION 12.10 CANCELLATION OF CONVERTED SECURITIES.

        All Securities delivered for conversion shall be delivered to the
Trustee or its agent to be canceled by or at the direction of the Trustee, which
shall dispose of the same as provided in Section 3.9.

        SECTION 12.11 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

                                      -80-

<PAGE>

assets of the Company, the Person formed by such consolidation or resulting from
such merger or which acquires such assets, as the case may be, shall execute and
deliver to the Trustee a supplemental indenture providing that the Holder of
each Security then Outstanding shall have the right thereafter, during the
period such Security shall be convertible as specified in Section 12.1, 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) 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 (B) 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 12.11 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. The above provisions of this Section 12.11 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 as provided in Section 1.6 promptly upon
such execution.

        Neither the Trustee nor any Conversion Agent 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 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 Officers' Certificate or Opinion of Counsel with respect
thereto, which the Company shall cause to be furnished to the Trustee upon
request.

        SECTION 12.12 RIGHTS ISSUED IN RESPECT OF COMMON STOCK.

        Rights, options or warrants distributed by the Company to all holders of
Common Stock entitling the holders thereof to subscribe for or purchase shares
of the Company's capital stock

                                      -81-

<PAGE>

(either initially or under certain circumstances), which rights, options or
warrants, until the occurrence of a specified event or events ("Trigger Event"):

        (i) are deemed to be transferred with such shares of Common Stock,

        (ii) are not exercisable, and

        (iii) are also issued in respect of future issuances of Common Stock

shall not be deemed distributed for purposes of Section 12.4(2) until the
occurrence of the earliest Trigger Event. If such right, option or warrant is
subject to subsequent events, upon the occurrence of which such right, option or
warrant shall become exercisable to purchase different securities, evidences of
indebtedness or other assets or entitle the holder to purchase a different
number or amount of the foregoing or to purchase any of the foregoing at a
different purchase price, then the occurrence of each such event shall be deemed
to be the date of issuance and record date with respect to a new right, option
or warrant (and a termination or expiration of the existing right, option or
warrant without exercise by the holder thereof). In addition, in the event of
any distribution (or deemed distribution) of rights, options or warrants, or any
Trigger Event or other event (of the type described in the preceding sentence)
with respect thereto, that shall have resulted in an adjustment to the
Conversion Rate under Section 12.4(2), (1) in the case of any such rights,
options or warrants which shall all have been redeemed or repurchased without
exercise by any holders thereof, the Conversion Rate shall be readjusted upon
such final redemption or repurchase to give effect to such distribution or
Trigger Event, as the case may be, as though it were a cash distribution, equal
to the per share redemption or repurchase price received by a holder of Common
Stock with respect to such rights, options or warrants (assuming such holder had
retained such rights, options or warrants), made to all holders of Common Stock
as of the date of such redemption or repurchase, and (2) in the case of any such
rights, options or warrants all of which shall have expired without exercise by
any holder thereof, the Conversion Price shall be readjusted as if such issuance
had not occurred.

        SECTION 12.13 RESPONSIBILITY OF TRUSTEE FOR CONVERSION PROVISIONS.

        The Trustee, subject to the provisions of Section 6.1, and any
Conversion Agent shall not at any time be under any duty or responsibility to
any Holder to determine whether any facts exist which may require any adjustment
of the Conversion Rate, or with respect to the nature or extent of any such
adjustment when made, or with respect to the method employed, or herein or in
any supplemental indenture provided to be employed, in making the same, or
whether a supplemental indenture need be entered into. Neither the Trustee,
subject to the provisions of Section 6.1, nor any Conversion Agent shall be
accountable with respect to the validity or value (or the kind or amount) of any
Common Stock, or of any other securities or property or cash, which may at any
time be issued or delivered upon the conversion of any Security; and it or they
do not make any representation with respect thereto. Neither the Trustee,
subject to the provisions of Section 6.1, nor any Conversion Agent shall be
responsible for any failure of the

                                      -82-

<PAGE>

Company to make or calculate any cash payment or to issue, transfer or deliver
any shares of Common Stock or share certificates or other securities or property
or cash upon the surrender of any Security for the purpose of conversion; and
the Trustee, subject to the provisions of Section 6.1, and any Conversion Agent
shall not be responsible for any failure of the Company to comply with any of
the covenants of the Company contained in this Article.](68)

                                  ARTICLE XIII

                           SUBORDINATION OF SECURITIES

               SECTION 13.1 SECURITIES SUBORDINATE TO SENIOR DEBT.

        The Company covenants and agrees, and each Holder, by its acceptance
thereof, likewise covenants and agrees, that, to the extent and in the manner
hereinafter set forth in this Article (subject to the provisions of Article IV),
the indebtedness represented by the Securities and the payment of the principal
of, or premium (including any Make-Whole Payment), if any, or interest on, each
and all of the Securities (including, but not limited to, the Redemption Price
with respect to the Securities to be called for redemption in accordance with
Article XI or the Repurchase Price with respect to Securities submitted for
repurchase in accordance with Article XIV), are hereby expressly made
subordinate and subject in right of payment to the prior payment in full in cash
of all Senior Debt.

        SECTION 13.2 NO PAYMENT IN CERTAIN CIRCUMSTANCES, PAYMENT OVER OF
PROCEEDS UPON DISSOLUTION, ETC.

        No payment shall be made with respect to the principal of, or premium
(including any Make-Whole Payment), 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 XI or the
Repurchase Price with respect to Securities submitted for repurchase in
accordance with Article XIV) except payments and distributions made by the
Trustee as permitted by Section 13.9, if:

        (i) a default in the payment of principal, premium, if any, or interest
(including a default under any repurchase or redemption obligation) or other
amounts with respect to 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) unless and until such default
shall have been cured or waived or shall have ceased to exist; or

        (ii) any other event of default occurs and is continuing with respect to
Designated Senior Debt that then permits holders of such Designated Senior Debt
to accelerate its maturity

----------

        (68) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -83-

<PAGE>

and the Trustee receives a notice of the default (a "Payment Blockage Notice")
from a Representative or holder of Designated Senior Debt or the Company.

        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 (A) at least 365 days shall have
elapsed since the initial effectiveness of the immediately prior Payment
Blockage Notice, and (B) all scheduled payments of principal, premium (including
any Make-Whole Payment), if any, and interest on the Securities that have come
due have been paid in full in cash (or, at the election of the Company and to
the extent permitted by the Indenture, shares of Common Stock). No nonpayment
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 default referred to in clause (i) above, the date
upon which the default is cured or waived or ceases to exist, or

        (2) in the case of a default referred to in clause (ii) above, the date
upon which the default is cured or waived or ceases to exist or 179 days pass
after notice is received if the maturity of such Designated Senior Debt has not
been accelerated, unless this Article XIII otherwise prohibits the payment or
distribution at the time of such payment or distribution.

        In the event of (a) any insolvency or bankruptcy case or proceeding, or
any receivership, liquidation, reorganization or other similar case or
proceeding in connection therewith, relative to the Company or to its creditors,
as such, or to its assets, or (b) any liquidation, dissolution or other winding
up of the Company, whether voluntary or involuntary and whether or not involving
insolvency or bankruptcy, or (c) any assignment for the benefit of creditors or
any other marshaling of assets and liabilities of the Company, then and in any
such event the holders of Senior Debt shall be entitled to receive payment in
full in cash of all amounts due or to become due on or in respect of all Senior
Debt before the Holders of the Securities are entitled to receive any payment on
account of principal of (or premium, including any Make-Whole Payment, if any)
or interest on the Securities or on account of the purchase, redemption or other
acquisition of Securities, and to that end the holders of Senior Debt shall be
entitled to receive, for application to the payment thereof, any payment or
distribution of any kind or character, whether in cash, property or securities,
which may be payable or deliverable in respect of the Securities in any such
case, proceeding, dissolution, liquidation or other winding up or event.

        In the event that, notwithstanding the foregoing provisions of this
Section, the Trustee or the Holder of any Security shall have received any
payment or distribution of assets of the Company of any kind or character,
whether in cash, securities or other property, before all Senior Debt is paid in
full in cash, then and in such event such payment or distribution shall be paid
over or delivered forthwith to the trustee in bankruptcy, receiver, liquidating
trustee, custodian,

                                      -84-

<PAGE>

assignee, agent or other Person making payment or distribution of assets of 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, after giving effect
to any concurrent payment or distribution to or for the holders of Senior Debt.

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

        In the event that, notwithstanding the foregoing, the Company shall make
any payment to the Trustee or the Holder of any Security prohibited by the
foregoing provisions of this Section, then and in such event such payment shall
be paid over and delivered forthwith to the Company, in the case of the Trustee,
or the Trustee, in the case of such Holder.

        SECTION 13.3 PRIOR PAYMENT TO SENIOR DEBT UPON ACCELERATION OF
SECURITIES.

        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 (including any
Make-Whole Payment), 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 XI or the Repurchase Price with respect to
the Securities submitted for repurchase in accordance with Article XIV), except
payments and distributions made by the Trustee as permitted by Section 13.9,
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.

                                      -85-

<PAGE>

        SECTION 13.4 PAYMENT PERMITTED IF NO DEFAULT.

        Nothing contained in this Article or elsewhere in this Indenture or in
any of the Securities shall prevent (a) the Company, at any time except during
the pendency of any case, proceeding, dissolution, liquidation or other winding
up, assignment for the benefit of creditors or other marshaling of assets and
liabilities of the Company referred to in Section 13.2, or during the
circumstances referred to in the first paragraph of Section 13.2, or under the
conditions described in Section 13.3, from making payments at any time of
principal of (and premium (including any Make-Whole Payment), if any) or
interest on the Securities, or (b) the application by the Trustee of any money
deposited with it hereunder to the payment of or on account of the principal of
(and premium (including any Make-Whole Payment), if any) or interest on the
Securities, if, at the time of such application by the Trustee, it did not have
knowledge that such payment would have been prohibited by the provisions of this
Article.

        SECTION 13.5 SUBROGATION TO RIGHTS OF HOLDERS OF SENIOR DEBT.

        Subject to the payment in full in cash of all Senior Debt, 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 to the rights of the holders of such Senior Debt to receive
payments and distributions of cash, property and securities applicable to the
Senior Debt until the principal of (and premium (including any Make-Whole
Payment), if any) and interest on the Securities shall be paid in full. For
purposes of such subrogation, no payments or distributions to the holders of the
Senior 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, and no payments over pursuant to the provisions of this Article to the
holders of Senior Debt by Holders of the Securities or the Trustee, shall, as
among the Company, its creditors other than holders of Senior Debt and the
Holders of the Securities, be deemed to be a payment or distribution by the
Company to or on account of the Senior Debt.

        SECTION 13.6 PROVISIONS SOLELY TO DEFINE RELATIVE RIGHTS.

        The provisions of this Article are and are intended solely for the
purpose of defining the relative rights of the Holders of the Securities on the
one hand and the holders of Senior Debt on the other hand. Nothing contained in
this Article or elsewhere in this Indenture or in the Securities is intended to
or shall (i) impair, as among the Company, its creditors other than 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, including any Make-Whole Payment, if any) and
interest on the Securities as and when the same shall become due and payable in
accordance with their terms; or (ii) affect the relative rights against the
Company of the Holders of the Securities and creditors of the Company other than
the holders of Senior Debt; or (iii) prevent the Trustee or the Holder of any
Security from exercising all remedies otherwise permitted by applicable law upon
default under this Indenture, subject to the rights, if any, under this Article
of the holders of Senior Debt to receive cash, property and securities otherwise
payable or deliverable to the Trustee or such Holder.

                                      -86-

<PAGE>

        SECTION 13.7 TRUSTEE TO EFFECTUATE SUBORDINATION.

        Each Holder by its acceptance thereof authorizes and directs the Trustee
on its behalf to take such action as may be necessary or appropriate to
effectuate the subordination provided in this Article and appoints the Trustee
its attorney-in-fact for any and all such purposes. Without limiting the
generality of the foregoing, the Trustee shall, if requested in writing by a
Representative or a holder of Designated Senior Debt, timely file proofs of
claim under Section 5.4 hereof in respect of the Securities prior to any "bar
date" or deadline for the filing thereof.

        SECTION 13.8 NO WAIVER OF SUBORDINATION PROVISIONS.

        No right of any present or future holder of any Senior Debt to enforce
subordination as herein provided shall at any time in any way be prejudiced or
impaired by any act or failure to act on the part of the Company or by any act
or failure to act, in good faith, by any such holder of any Senior Debt, or by
any non- compliance by the Company with the terms, provisions and covenants of
this Indenture, regardless of any knowledge thereof any such holder may have or
be otherwise charged with.

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

        SECTION 13.9 NOTICE TO TRUSTEE.

        The Company shall give prompt written notice to the Trustee of any
fact known to the Company which would prohibit the making of any payment to
or by the Trustee in respect of the Securities. Notwithstanding the
provisions of this Article or any other provision of this Indenture, the
Trustee shall not be charged with knowledge of the existence of any facts
which would prohibit the making of any payment to or by the Trustee in
respect of the Securities, unless and until a Responsible Officer of the
Trustee shall have received written notice thereof from the Company or a
Representative or a holder of Senior Debt (including, without limitation, a
holder of Designated Senior Debt) and, prior to 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,
however, that if the Trustee shall not have received the notice provided for
in this Section 13.9 at least three Business Days prior to the date upon
which by the terms hereof

                                      -87-

<PAGE>

any money may become payable for any purpose (including, without limitation, the
payment of the principal of (and premium (including any Make-Whole Payment), if
any) or interest on any Security), then, anything herein contained to the
contrary notwithstanding, the Trustee shall have full power and authority to
receive such money and to apply the same to the purpose for which such money was
received and shall not be affected by any notice to the contrary which may be
received by it within three Business Days prior to such date.

        Notwithstanding anything in this Article XIII 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 13.2 and 13.3.

        Subject to the provisions of Section 6.1, the Trustee shall be entitled
to rely on the delivery to it of a written notice by a Person representing
himself to be a Representative or a holder of Senior Debt (including, without
limitation, a holder of Designated Senior Debt) to establish that such notice
has been given by a Representative or a holder of Senior Debt (including,
without limitation, a holder of Designated Senior Debt). In the event that the
Trustee determines in good faith that further evidence is required with respect
to the right of any Person as a holder of Senior Debt to participate in any
payment or distribution pursuant to this Article, the Trustee may request such
Person to furnish evidence to the reasonable satisfaction of the Trustee as to
the amount of Senior 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, and if such evidence
is not furnished, the Trustee may defer any payment to such Person pending
judicial determination as to the right of such Person to receive such payment.

        SECTION 13.10 RELIANCE ON JUDICIAL ORDER OR CERTIFICATE OF LIQUIDATING
AGENT.

        Upon any payment or distribution of assets of the Company referred to in
this Article, the Trustee, subject to the provisions of Section 6.1, and the
Holders of the Securities shall be entitled to rely upon any order or decree
entered by any court of competent jurisdiction in which such insolvency,
bankruptcy, receivership, liquidation, reorganization, dissolution, winding up
or similar case or proceeding is pending, or a certificate of the trustee in
bankruptcy, receiver, liquidating trustee, custodian, assignee for the benefit
of creditors, agent or other Person making such payment or distribution,
delivered to the Trustee or to the Holders, for the purpose of ascertaining the
Persons entitled to participate in such payment or distribution, the holders of
the Senior Debt and other indebtedness of the Company, the amount thereof or
payable thereon, the amount or amounts paid or distributed thereon and all other
facts pertinent thereto or to this Article.

        SECTION 13.11 TRUSTEE NOT FIDUCIARY FOR HOLDERS OF SENIOR DEBT.

        The Trustee shall not be deemed to owe any fiduciary duty to the holders
of Senior Debt and shall not be liable to any such holders if it shall in good
faith mistakenly pay over or

                                      -88-

<PAGE>

distribute to Holders or to the Company or to any other Person cash, property or
securities to which any holders of Senior Debt shall be entitled by virtue of
this Article or otherwise.

         With respect to holders of Senior Debt, the Trustee undertakes to
perform or to observe only such of its covenants or obligations as are
specifically set forth in this Article and no implied covenants or
obligations with respect to holders of Senior Debt shall be read into this
Indenture against the Trustee.

        SECTION 13.12 RELIANCE BY HOLDERS OF SENIOR DEBT ON SUBORDINATION
PROVISIONS.

        Each Holder by accepting a Security acknowledges and agrees that the
foregoing subordination provisions are, and are intended to be, an inducement
and a consideration to each holder of any Senior Debt, whether such Senior Debt
was created or acquired before or after the issuance of the Securities, to
acquire and continue to hold, or to continue to hold, such Senior Debt and such
holder of Senior Debt shall be deemed conclusively to have relied on such
subordination provisions in acquiring and continuing to hold, or in continuing
to hold, such Senior Debt, and no amendment or modification of the provisions
contained herein shall diminish the rights of such holders of Senior Debt unless
such holders shall have agreed in writing thereto.

        SECTION 13.13 RIGHTS OF TRUSTEE AS HOLDER OF SENIOR DEBT; PRESERVATION
OF TRUSTEE'S RIGHTS.

        The Trustee in its individual capacity shall be entitled to all the
rights set forth in this Article with respect to any Senior Debt which may at
any time be held by it, to the same extent as any other holder of Senior Debt,
and nothing in this Indenture shall deprive the Trustee of any of its rights as
such holder.

        Nothing in this Article shall apply to claims of, or payments to, the
Trustee under or pursuant to Section 6.7.

        SECTION 13.14 ARTICLE APPLICABLE TO PAYING AGENTS.

        In case at any time any Paying Agent other than the Trustee shall have
been appointed by the Company and be then acting hereunder, the term "Trustee"
as used in this Article shall in such case (unless the context otherwise
requires) be construed as extending to and including such Paying Agent within
its meaning as fully for all intents and purposes as if such Paying Agent were
named in this Article in addition to or in place of the Trustee; provided,
however, that Section 13.13 shall not apply to the Company or any Affiliate of
the Company if it or such Affiliate acts as Paying Agent.

                                      -89-

<PAGE>

        SECTION 13.15 CERTAIN [CONVERSIONS AND](69) REPURCHASES DEEMED PAYMENT.

        For the purposes of this Article only, (i) the issuance and delivery of
junior securities [upon conversion of Securities in accordance with Article XII
or](70) upon the repurchase of Securities in accordance with Article XIV shall
not be deemed to constitute a payment or distribution on account of the
principal of or premium or interest on Securities or on account of the
purchase or other acquisition of Securities[, and (ii) the payment,
issuance or delivery of cash (except in satisfaction of fractional shares
pursuant to Section 12.3 or 14.3(7)), property or securities (other than
junior securities) upon conversion of a Security shall be deemed to
constitute payment on account of the principal of such Security](71). For the
purposes of this Section, the term "junior securities" means [(a) shares of any
stock of any class of the Company and securities into which the Securities
are convertible pursuant to Article XII and (b)](72) 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 or elsewhere in this Indenture or in the Securities is intended to or
shall impair, as among the Company, its creditors other than holders of
Senior Debt and the Holders of the Securities, the right, which is absolute
and unconditional, of the Holder of any Security [to convert such Security in
accordance with Article XII or](73) to exchange such Security for Common Stock
in accordance with Article XIV if the Company elects to satisfy the obligations
under Article XIV by the delivery of Common Stock.

----------

        (69) INSERT IF SECURITIES ARE CONVERTIBLE

        (70) INSERT IF SECURITIES ARE CONVERTIBLE

        (71) INSERT IF SECURITIES ARE CONVERTIBLE

        (72) INSERT IF SECURITIES ARE CONVERTIBLE

        (73) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -90-

<PAGE>

                                   ARTICLE XIV

                     REPURCHASE OF SECURITIES AT THE OPTION
                     OF THE HOLDER UPON A CHANGE IN CONTROL

        SECTION 14.1 RIGHT TO REQUIRE REPURCHASE.

        In the event that a Change in Control (as hereinafter defined) shall
occur, then each Holder shall have the right, at the Holder's option, but
subject to the provisions of Section 14.2, to require the Company to repurchase,
and upon the exercise of such right the Company shall repurchase, all of such
Holder's Securities not theretofore called for redemption, or any portion of the
principal amount thereof that an integral multiple of U.S. $1,000 (provided that
no single Security may be repurchased in part unless the portion of the
principal amount of such Security to be Outstanding after such repurchase is
equal to an integral multiple of U.S. $1,000), on the date (the "Repurchase
Date") that is 45 days after the date of the Company Notice (as defined in
Section 14.3) at a purchase price equal to _____% of the principal amount of the
Securities to be repurchased plus interest accrued to the Repurchase Date (the
"Repurchase Price"); provided, however, that installments of interest on
Securities whose Stated Maturity is on or prior to the Repurchase Date shall be
payable to the Holders of such Securities, or one or more Predecessor
Securities, registered as such on the relevant Record Date according to their
terms and the provisions of Section 3.7. Such right to require the repurchase of
the Securities shall not continue after a discharge of the Company from its
obligations with respect to the Securities in accordance with Article IV, unless
a Change in Control shall have occurred prior to such discharge. At the option
of the Company, the Repurchase Price may be paid in cash or, subject to the
fulfillment by the Company of the conditions set forth Section 14.2, by delivery
of shares of Common Stock having a fair market value equal to the Repurchase
Price. Whenever in this Indenture (including Sections 2.2, 3.1, 5.1(1) and 5.8)
there is a reference, in any context, to the principal of any Security as of any
time, such reference shall be deemed to include reference to the Repurchase
Price payable in respect of such Security to the extent that such Repurchase
Price is, was or would be so payable at such time, and express mention of the
Repurchase Price in any provision of this Indenture shall not be construed as
excluding the Repurchase Price in those provisions of this Indenture when such
express mention is not made; provided, however, that for the purposes of Article
XIII such reference shall be deemed to include reference to the Repurchase Price
only to the extent the Repurchase Price is payable in cash.

        SECTION 14.2 CONDITIONS TO THE COMPANY'S ELECTION TO PAY THE REPURCHASE
PRICE OR THE MAKE-WHOLE PAYMENT IN COMMON STOCK.

        The Company may elect to pay the Repurchase Price by delivery of shares
of Common Stock pursuant to Section 14.1, and the Company may elect to pay the

                                      -91-

<PAGE>

Make-Whole Payment by delivery of shares of Common Stock pursuant to Section
2.2, if and only if the following conditions shall have been satisfied:

        (1) The shares of Common Stock deliverable in payment of the Repurchase
Price or Make-Whole Payment, as the case may be, shall have a fair market value
as of the Repurchase Date or the Redemption Date, as the case may be, of not
less than the Repurchase Price or Make-Whole Payment, as the case may be. For
purposes of Section 14.1 and this Section 14.2, the fair market value of shares
of Common Stock shall be determined by the Company and shall be equal to ____%
of the average of the Closing Price Per Share for the five consecutive Trading
Days immediately preceding and including the third Trading Day prior to the
Repurchase Date or the Redemption Date, as the case may be;

        (2) The Repurchase Price or Make-Whole Payment, as the case may be,
shall be paid only in cash in the event any shares of Common Stock to be issued
upon repurchase or redemption, as the case may be, of Securities hereunder (i)
require registration under any federal securities law before such shares may be
freely transferable without being subject to any transfer restrictions under the
Securities Act upon repurchase and if such registration is not completed or does
not become effective prior to the Repurchase Date or the Redemption Date, as the
case may be, and/or (ii) require registration with or approval of any
governmental authority under any state law or any other federal law before such
shares may be validly issued or delivered upon repurchase or redemption, as the
case may be, and if such registration is not completed or does not become
effective or such approval is not obtained prior to the Repurchase Date or the
Redemption Date, as the case may be;

        (3) Payment of the Repurchase Price or Make-Whole Payment, as the case
may be, may not be made in Common Stock unless such stock is, or shall have
been, approved for quotation on the Nasdaq National Market or listed on a
national securities exchange, in either case, prior to the Repurchase Date or
the Redemption Date, as the case may be; and

        (4) All shares of Common Stock which may be issued upon repurchase or
redemption, as the case may be, of Securities will be issued out of the
Company's authorized but unissued Common Stock and, will upon issue, be duly and
validly issued and fully paid and non-assessable and free of any preemptive
rights or rights of first refusal.

        If all of the conditions set forth in this Section 14.2 are not
satisfied in accordance with the terms thereof, the Repurchase Price or
Make-Whole Payment, as the case may be, shall be paid by the Company only in
cash.

        SECTION 14.3 NOTICES; METHOD OF EXERCISING REPURCHASE RIGHT, ETC.

        (1) Unless the Company shall have theretofore called for redemption all
of the Outstanding Securities, on or before the 30th day after the occurrence of
a Change in Control, the Company or, at the request and expense of the Company
on or before the 30th day after such occurrence, the Trustee, shall give to all
Holders, in the manner provided in Section 1.6, notice (the "Company Notice") of
the occurrence of the Change of Control and of the repurchase right set forth
herein arising as a result thereof. The Company shall also deliver a copy of
such notice

                                      -92-

<PAGE>

of a repurchase right to the Trustee and notify one or more
nationally-recognized reporting institutions such as Bloomberg of the Change in
Control and repurchase right.

        Each notice of a repurchase right shall state:

                (i) the Repurchase Date,

                (ii) the date by which the repurchase right must be exercised,

                (iii) the Repurchase Price, and whether the Repurchase Price
        shall be paid by the Company in cash or by delivery of shares of Common
        Stock,

                (iv) a description of the procedure which a Holder must follow
        to exercise a repurchase right, and the place or places where such
        Securities are to be surrendered for payment of the Repurchase Price and
        accrued interest, if any to the Repurchase Date,

                (v) that on the Repurchase Date the Repurchase Price, and
        accrued interest, if any to the Repurchase Date, will become due and
        payable upon each such Security designated by the Holder to be
        repurchased, and that interest thereon shall cease to accrue on and
        after said date,

                [(vi) the Conversion Rate then in effect, the date on which the
        right to convert the principal amount of the Securities to be
        repurchased will terminate and the place or places where such Securities
        may be surrendered for CONVERSION,](74) and

                (vii) the place or places that the Notice of Election of Holder
        to Require Repurchase as specified in Section 2.2 shall be delivered.

        No failure of the Company to give the foregoing notices or defect
therein shall limit any Holder's right to exercise a repurchase right or affect
the validity of the proceedings for the repurchase of Securities.

        If any of the foregoing provisions or other provisions of this Article
XIV are inconsistent with applicable law, such law shall govern.

        (2) To exercise a repurchase right, a Holder shall deliver to the
Trustee on or before the 30th day after the date of the Company Notice (i)
irrevocable written notice of the Holder's exercise of such right, which notice
shall set forth the name of the Holder, the principal amount of the Securities
to be repurchased (and, if any Security is to repurchased in part, the serial
number thereof, the portion of the principal amount thereof to be repurchased
and the name of the Person in which the portion thereof to remain Outstanding
after such repurchase is to be

----------

        (74) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -93-

<PAGE>

registered) and a statement that an election to exercise the repurchase right is
being made thereby, and, in the event that the Repurchase Price shall be paid in
shares of Common Stock, the name or names (with addresses) in which the
certificate or certificates for shares of Common Stock shall be issued, and (ii)
the Securities with respect to which the repurchase right is being exercised.
Such written notice shall be irrevocable[, except that the right of the Holder
to convert the Securities with respect to which the repurchase right is being
exercised shall continue until the close of business on the Business Day
immediately preceding the Repurchase Date](75).

        (3) In the event that a repurchase right shall be exercised in
accordance with the terms hereof, the Company shall pay or cause to be paid to
the Trustee the Repurchase Price in cash or shares of Common Stock, as provided
above, for payment to the Holder on the Repurchase Date or, if shares of Common
Stock are to be paid, as promptly after the Repurchase Date as practicable,
together with accrued and unpaid interest to the Repurchase Date payable with
respect to the Securities as to which the repurchase right has been exercised;
provided, however, that installments of interest that mature on or prior to the
Repurchase Date shall be payable in cash to the Holders of such Securities, or
one or more Predecessor Securities, registered as such at the close of business
on the relevant Regular Record Date.

        (4) If any Security (or portion thereof) surrendered for repurchase
shall not be so paid on the Repurchase Date, the principal amount of such
Security (or portion thereof, as the case may be) shall, until paid, bear
interest to the extent permitted by applicable law from the Repurchase Date at
the rate of _____% per annum[, and each Security shall remain convertible into
Common Stock until the principal of such Security (or portion thereof, as the
case may be) shall have been paid or duly provided for](76).

        (5) Any Security which is to be repurchased only in part shall be
surrendered to the Trustee (with, if the Company or the Trustee so requires, due
endorsement by, or a written instrument of transfer in form satisfactory to the
Company and the Trustee duly executed by, the Holder thereof or his attorney
duly authorized in writing), and the Company shall execute, and the Trustee
shall authenticate and make available for delivery to the Holder of such
Security without service charge, a new Security or Securities, containing
identical terms and conditions, each in an authorized denomination in aggregate
principal amount equal to and in exchange for the unrepurchased portion of the
principal of the Security so surrendered.

        (6) Any issuance of shares of Common Stock in respect of the Repurchase
Price shall be deemed to have been effected immediately prior to the close of
business on the Repurchase Date and the Person or Persons in whose name or names
any certificate or certificates for shares of Common Stock shall be issuable
upon such repurchase shall be deemed to have become on the Repurchase Date the
holder or holders of record of the shares represented thereby; provided,
however, that any surrender for repurchase on a date when the stock transfer
books of the

----------

        (75) INSERT IF SECURITIES ARE CONVERTIBLE

        (76) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -94-

<PAGE>

Company shall be closed shall constitute the Person or Persons in whose name or
names the certificate or certificates for such shares are to be issued as the
record holder or holders thereof for all purposes at the opening of business on
the next succeeding day on which such stock transfer books are open. No payment
or adjustment shall be made for dividends or distributions on any Common Stock
issued upon repurchase of any Security declared prior to the Repurchase Date.

        (7) No fractions of shares shall be issued upon repurchase of
Securities. If more than one Security shall be repurchased from the same Holder
and the Repurchase Price shall be payable in shares of Common Stock, the number
of full shares which shall be issuable upon such repurchase shall be computed on
the basis of the aggregate principal amount of the Securities so repurchased.
Instead of any fractional share of Common Stock which would otherwise be
issuable on the repurchase of any Security or Securities, the Company will
deliver to the applicable Holder its check for the current market value of such
fractional share. The current market value of a fraction of a share is
determined by multiplying the current market price of a full share by the
fraction, and rounding the result to the nearest cent. For purposes of this
Section, the current market price of a share of Common Stock is the Closing
Price Per Share on the Trading Day immediately preceding the Repurchase Date.

        (8) Any issuance and delivery of certificates for shares of Common Stock
on repurchase of Securities shall be made without charge to the Holder being
repurchased for such certificates or for any tax or duty in respect of the
issuance or delivery of such certificates or the securities represented thereby;
provided, however, that the Company shall not be required to pay any tax or duty
which may be payable in respect of (i) income of the Holder or (ii) any transfer
involved in the issuance or delivery of certificates for shares of Common Stock
in a name other than that of the Holder of the Securities being repurchased, and
no such issuance or delivery shall be made unless and until the Person
requesting such issuance or delivery has paid to the Company the amount of any
such tax or duty or has established, to the reasonable satisfaction of the
Company, that such tax or duty has been paid.

        (9) All Securities delivered for repurchase shall be delivered to the
Trustee to be canceled at the direction of the Trustee, which shall dispose of
the same as provided in Section 3.9.

        SECTION 14.4 CERTAIN DEFINITIONS.

        For purposes of this Article XIV,

        (1) the term "beneficial owner" shall be determined in accordance with
Rule 13d-3, as in effect on the date of the original execution of this
Indenture, promulgated by the Commission pursuant to the Exchange Act;

                                      -95-

<PAGE>

        (2) a "Change in Control" shall be deemed to have occurred at the time,
after the original issuance of the Securities, of:

                        (i) the acquisition by any Person of beneficial
                ownership, directly or indirectly, through a purchase, merger or
                other acquisition transaction or series of transactions, of
                shares of capital stock of the Company entitling such person to
                exercise 50% or more of the total voting power of all shares of
                capital stock of the Company entitled to vote generally in the
                elections of directors, other than any such acquisition by the
                Company, any subsidiary of the Company or any employee benefit
                plan of the Company; or

                        (ii) any consolidation of the Company with, or merger of
                the Company into, any other Person, any merger of another Person
                into the Company, or any conveyance, sale, transfer or lease of
                all or substantially all of the assets of the Company to another
                Person (other than (a) any such transaction [(x)](77) which does
                not result in any reclassification, conversion, exchange or
                cancellation of outstanding shares of capital stock of the
                Company and (y) pursuant to which the holders of the Common
                Stock immediately prior to such transaction have the entitlement
                to exercise, directly or indirectly, 50% or more of the total
                voting power of all shares of capital stock entitled to vote
                generally in the election of directors of the continuing or
                surviving Person immediately after such transaction and (b) any
                merger which is effected solely to change the jurisdiction of
                incorporation of the Company and results in a reclassification,
                conversion or exchange of outstanding shares of Common Stock
                into solely shares of common stock); provided, however, that a
                Change in Control shall not be deemed to have occurred if (x)
                the Closing Price Per Share on any five Trading Days within the
                period of 10 consecutive Trading Days ending immediately after
                the later of the date of the Change in Control or the date of
                the public announcement of the Change in Control (in the case of
                a Change in Control under clause (i) above) or the period of 10
                consecutive Trading Days ending immediately before the Change in
                Control (in the case of a Change in Control under clause (ii)
                above) shall equal or exceed _______________ [or (y) all of the
                consideration (excluding cash payments for fractional shares and
                cash payments made pursuant to dissenters' appraisal rights) in
                a merger or consolidation otherwise constituting a Change of
                Control under clause (i) and/or clause (ii) above consists of
                shares of common stock traded on a national securities exchange
                or quoted on the Nasdaq National Market (or will be so traded or
                quoted immediately following such merger or consolidation) and
                as a result of such merger or consolidation the notes become
                convertible into such common stock](78).

        [(3) the term "Conversion Price" shall equal U.S. $1,000 divided by the
Conversion Rate (rounded to the nearest cent)](79); -- and

----------

        (77) INSERT IF SECURITIES ARE CONVERTIBLE

        (78) INSERT IF SECURITIES ARE CONVERTIBLE

        (79) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -96-

<PAGE>

        (4) for purposes of Section 14.4(2)(i), the term "Person" shall include
any syndicate or group which would be deemed to be a "Person" under Section
13(d)(3) of the Exchange Act, as in effect on the date of the original execution
of this Indenture.

        [SECTION 14.5 CONSOLIDATION, MERGER, ETC.

        In the case of any merger, consolidation, conveyance, sale, transfer or
lease of all or substantially all of the assets of the Company to which Section
12.11 applies, in which the Common Stock of the Company is changed or exchanged
as a result into the right to receive shares of stock and other securities or
property or assets (including cash) which includes shares of Common Stock of the
Company or common stock of another Person that are, or upon issuance will be,
traded on a United States national securities exchange or approved for trading
on an established automated over-the-counter trading market in the United States
and such shares constitute at the time such change or exchange becomes effective
in excess of 50% of the aggregate fair market value of such shares of stock and
other securities, property and assets (including cash) (as determined by the
Company, which determination shall be conclusive and binding), then the Person
formed by such consolidation or resulting from such merger or combination or
which acquires the properties or assets (including cash) of the Company, as the
case may be, shall execute and deliver to the Trustee a supplemental indenture
(which shall comply with the Trust Indenture Act as in force at the date of
execution of such supplemental indenture) modifying the provisions of this
Indenture relating to the right of Holders to cause the Company to repurchase
the Securities following a Change in Control, including without limitation the
applicable provisions of this Article XIV and the definitions of the Common
Stock and Change in Control, as appropriate, and such other related definitions
set forth herein as determined in good faith by the Company (which determination
shall be conclusive and binding), to make such provisions apply in the event of
a subsequent Change in Control to the common stock and the issuer thereof if
different from the Company and Common Stock of the Company (in lieu of the
Company and the Common Stock of the Company).](80)

                                   ARTICLE XV

         HOLDERS LISTS AND REPORTS BY TRUSTEE AND COMPANY; NON-RECOURSE

     SECTION 15.1 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 more than 15 days after the Regular Record Date,
a list, in such form as the Trustee may reasonably require, of the names and
addresses of the Holders as of such Regular Record Date, and

----------

        (80) INSERT IF SECURITIES ARE CONVERTIBLE

                                      -97-

<PAGE>

        (2) at such other times as the Trustee may reasonably request in
writing, within 30 days after the receipt by the Company of any such request, a
list of similar form and content as of a date not more than 15 days prior to the
time such list is furnished; excluding from any such list names and addresses
received by the Trustee acting in its capacity as Security Registrar.

        SECTION 15.2 PRESERVATION OF INFORMATION.

        (1) 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 15.1 and the names and
addresses of Holders received by the Trustee in its capacity as Security
Registrar. The Trustee may destroy any list, if any, furnished to it as provided
in Section 15.1 upon receipt of a new list so furnished.

        (2) 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 duties of the Trustee, shall be as provided by the
Trust Indenture Act.

        (3) Every Holder, 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 15.3 REPORTS BY TRUSTEE.

        (1) 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.

        (2) 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 the
Securities are listed, with the Commission and with the Company. The Company
will notify the Trustee when the Securities are listed on any stock exchange.

        SECTION 15.4 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

                                      -98-

<PAGE>

the Commission pursuant to Section 13 or 15(d) of the Exchange Act shall be
filed with the Trustee within 15 days after the same is so required to be filed
with the Commission.

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

                                   ARTICLE XVI

         IMMUNITY OF INCORPORATORS, STOCKHOLDERS, OFFICERS AND DIRECTORS

        SECTION 16.1 INDENTURE AND SECURITIES SOLELY CORPORATE OBLIGATIONS.

        No recourse for the payment of the principal of or premium (including
any Make-Whole Payment), if any, or interest on any Security 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, 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 waived and released as a condition
of, and as a consideration for, the execution of this Indenture and the issue of
the Securities.

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

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

SONUS NETWORKS, INC.

By:
   ____________________________
Name:
Title:

_______________________________,
as Trustee

By:
   ____________________________
Name:
Title:

                                      -99-<PAGE>

                                                                   EXHIBIT 10.1

                                1999 EQUITY PLAN
                                FOR EMPLOYEES OF
                     ALLIANCE IMAGING, INC. AND SUBSIDIARIES

1.       PURPOSE OF PLAN

         The 1999 Equity Plan for Employees of Alliance Imaging, Inc. and
Subsidiaries (the "Plan") is designed:

                  (a) to promote the long term financial interests and growth of
         Alliance Imaging, Inc. (the "Company") and its Subsidiaries by
         attracting and retaining management and personnel with the training,
         experience and ability to enable them to make a substantial
         contribution to the success of the Company's business;

                  (b) to motivate personnel by means of growth-related
         incentives to achieve long range goals; and

                  (c) to further the identity of interests of participants with
         those of the stockholders of the Company through opportunities for
         stock or stock-based ownership in the Company.

2.       DEFINITIONS

         As used in the Plan, the following words shall have the following
         meanings:

                  (a) "Affiliate" shall mean (i) with respect to any Person, any
         other Person directly or indirectly controlling, controlled by, or
         under common control with, such Person, and (ii) with respect to the
         Company, also any entity designated by the Board of Directors of the
         Company in which the Company or one of its Affiliates has an interest,
         and (iii) with respect to Kohlberg Kravis Roberts & Co., L.P. ("KKR"),
         also any Affiliate of any partner of KKR. For purposes of this Plan,
         "Person" means an individual, partnership, corporation, limited
         liability company, business trust, joint stock company, trust,
         unincorporated association, joint venture, governmental authority or
         other entity of whatever nature, and "control" shall have the meaning
         given such term under Rule 405 of the Securities Act.

                  (b) "Board of Directors" means the Board of Directors of the
         Company.

                  (c) "Committee" means the Compensation Committee of the Board
         of Directors or another committee of the Board designated by the Board
         to administer the Plan.

                  (d) "Common Stock" or "Share" means $.01 par value common
         stock of the Company.

<PAGE>

                  (e) "Employee" means a person, including an officer, in the
         regular full-time employment of the Company or one of its Subsidiaries.

                  (f) "Exchange Act" means the Securities Exchange Act of 1934,
         as amended.

                  (g) "Fair Market Value" means such value of a Share as
         reported for stock exchange transactions and/or determined in
         accordance with any applicable resolutions or regulations of the
         Committee in effect at the relevant time.

                  (h) "Grant" means a Non-Qualified Stock Option award made to a
         Participant pursuant to the Plan and described in Section 5.

                  (i) "Grant Agreement" means an agreement between the Company
         and a Participant that sets forth the terms, conditions and limitations
         applicable to a Grant.

                  (j) "Participant" means an Employee, consultant, or other
         person having a unique relationship with the Company or one of its
         Subsidiaries, to whom one or more Grants have been made and such Grants
         have not all been forfeited or terminated under the Plan; provided,
         however, a non-employee director of the Company or one of its
         Subsidiaries may not be a Participant.

                  (k) "Securities Act" means the Securities Act of 1933, as
         amended and the rules and regulations promulgated thereunder.

                  (l) "Stock Options" means the "Non-Qualified Stock Options"
         described in Section 5.

                  (m) "Subsidiary" means any corporation (or other entity) other
         than the Company in an unbroken chain of entities beginning with the
         Company if each of the entities, or group of commonly controlled
         entities, other than the last entity in the unbroken chain, then owns
         stock (or other equity interest) possessing 50% or more of the total
         combined voting power of all classes of equity in one of the other
         entities in such chain.

3.       ADMINISTRATION OF PLAN

                  (a) The Plan shall be administered by the Committee. The
         members of the Committee shall consist solely of individuals who are
         both "non-employee directors" as defined by Rule 16b-3 promulgated
         under the Exchange Act and "outside directors" for purposes of Section
         162(m) of the Internal Revenue Code of 1986, as amended (the "Code"),
         to the extent that the Company and its Employees are subject to Section
         16 of the Exchange Act or Section 162(m) of the Code. The Committee may
         adopt its own rules of procedure, and the action of a majority of the
         Committee, taken at a meeting or taken without a meeting by a writing
         signed by such majority, shall constitute action by the Committee. The
         Committee shall have the power, authority and the discretion to
         administer,

                                        2
<PAGE>

         construe and interpret the Plan and Grant Agreements, to make rules
         for carrying out the Plan and to make changes in such rules. Any such
         interpretations, rules, and administration shall be made and done in
         good faith and consistent with the basic purposes of the Plan.

                  (b) The Committee may delegate to the Chief Executive Officer
         and to other senior officers of the Company its duties under the Plan
         subject to such conditions and limitations as the Committee shall
         prescribe except that only the Committee may designate and make Grants
         to Participants who are subject to Section 16 of the Exchange Act or
         Section 162(m) of the Code.

                  (c) The Committee may employ attorneys, consultants,
         accountants, appraisers, brokers or other persons. The Committee, the
         Company, and the officers and directors of the Company shall be
         entitled to rely upon the advice, opinions or valuations of any such
         persons. Subject to the terms and conditions of this Plan and any
         applicable Grant Agreement, all actions taken and all interpretations
         and determinations made by the Committee in good faith shall be final
         and binding upon all Participants, the Company and all other interested
         persons. No member of the Committee shall be personally liable for any
         action, determination or interpretation made in good faith with respect
         to the Plan or the Grants, and all members of the Committee shall be
         fully protected by the Company with respect to any such action,
         determination or interpretation.

4.       ELIGIBILITY

         The Committee may from time to time make Grants under the Plan to such
Employees, consultants, or other persons having a unique relationship with the
Company or any of its Subsidiaries, and in such form and having such terms,
conditions and limitations as the Committee may determine. No Grants may be made
under this Plan to non-employee directors of the Company or any of its
Subsidiaries. Grants may be granted singly, in combination or in tandem. The
terms, conditions and limitations of each Grant under the Plan shall be set
forth in a Grant Agreement, in a form approved by the Committee, consistent,
however, with the terms of the Plan; provided, however, such Grant Agreement
shall contain provisions dealing with the treatment of Grants in the event of
the termination, death or disability of the Participant, and may also include
provisions concerning the treatment of Grants in the event of a change of
control of the Company.

5.       GRANTS

         From time to time, the Committee will grant options to purchase Common
Stock which are not "incentive stock options," within the meaning of Section 422
of the Internal Revenue Code of 1986, as amended. At the time of grant, the
Committee shall determine, and shall have specified in the Grant Agreement or
other Plan rules, the option exercise period, the option exercise price, and
such other conditions or restrictions on the grant or exercise of the Stock
Option as the Committee deems appropriate. In addition to other restrictions
contained in the Plan and Grant Agreement, Stock Options granted under this
Section 5 (i) may not be exercised more than 10 years after the date granted

                                   3
<PAGE>

and (ii) may not have an option exercise price less than 85% of the Fair
Market Value of Common Stock on the date the option is granted. Payment of
the option exercise price shall be made in cash or, with the consent of the
Committee, in shares of Common Stock (including shares acquired by
contemporaneous exercise of other Stock Options), or a combination thereof,
in accordance with the terms of the Plan, the Grant Agreement and any
applicable guidelines of the Committee in effect at the time.

6.       LIMITATIONS AND CONDITIONS

                  (a) The number of Shares available for Grants under this Plan
         shall be 632,500 shares of the authorized Common Stock as of the
         effective date of the Plan. Unless restricted by applicable law, Shares
         related to Grants that are forfeited, terminated, canceled or expire
         unexercised, shall immediately become available for Grants.

                  (b) No Grants shall be made under the Plan beyond ten years
         after the effective date of the Plan, but the terms of Grants made on
         or before the expiration thereof may extend beyond such expiration. At
         the time a Grant is made or amended or the terms or conditions of a
         Grant are changed, the Committee may provide for limitations or
         conditions on such Grant.

                  (c) Nothing contained herein shall affect the right of the
         Company or any Subsidiary to terminate any Participant's employment at
         any time or for any reason.

                  (d) Except as otherwise prescribed by the Committee, the
         amounts of the Grants for any employee of a Subsidiary, along with
         interest, dividends, and other expenses accrued on deferred Grants
         shall be charged to the Participant's employer during the period for
         which the Grant is made. If the Participant is employed by more than
         one Subsidiary or by a combination of the Company and a Subsidiary
         during the period for which the Grant is made, the Participant's Grant
         and related expenses will be allocated between the companies employing
         the Participant in a manner prescribed by the Committee.

                  (e) Other than as specifically provided by will or by the
         applicable laws of descent and distribution or the terms of any
         applicable trust, no benefit under the Plan shall be subject in any
         manner to anticipation, alienation, sale, transfer, assignment, pledge,
         encumbrance, or charge, and any attempt to do so shall be void. No such
         benefit shall, prior to receipt thereof by the Participant, be in any
         manner liable for or subject to the debts, contracts, liabilities,
         engagements, or torts of the Participant.

                  (f) Participants shall not be, and shall not have any of the
         rights or privileges of, stockholders of the Company in respect of any
         Shares purchasable or otherwise acquired in connection with any Grant
         unless and until certificates representing any such Shares have been
         issued by the Company to such Participants; provided however that no
         delay in the issuance of certificates due to

                                         4
<PAGE>

         be issued hereunder representing any such Shares shall operate to
         impair or prejudice any Participant's rights to participate in a
         corporate transaction providing for the disposition of such Shares.

                  (g) No election as to benefits or exercise of Stock Options or
         other rights may be made during a Participant's lifetime by anyone
         other than the Participant except by a legal representative appointed
         for or by the Participant.

                  (h) Absent express provisions to the contrary, no Grant under
         this Plan shall be deemed "compensation" for purposes of computing
         benefits or contributions under any retirement plan of the Company or
         its Subsidiaries and shall not affect any benefits under any other
         benefit plan of any kind or subsequently in effect under which the
         availability or amount of benefits is related to level of compensation.
         This Plan is not a "Pension Plan" or "Welfare Plan" under the Employee
         Retirement Income Security Act of 1974, as amended.

                  (i) Unless the Committee determines otherwise, no benefit or
         promise under the Plan shall be secured by any specific assets of the
         Company or any of its Subsidiaries, nor shall any assets of the Company
         or any of its Subsidiaries be designated as attributable or allocated
         to the satisfaction of the Company's obligations under the Plan.

                  (j) To the extent designated by the Committee, no Grant shall
         be effective unless and until it is approved by the stockholders of the
         Company holding more than 75% of the voting power of all outstanding
         Common Stock of the Company in accordance with the provisions of
         Section 280G(b)(5) of the Code.

7.       TRANSFERS AND LEAVES OF ABSENCE

         For purposes of the Plan, unless the Committee determines otherwise:
(a) a transfer of a Participant's employment without an intervening period of
separation among the Company and any Subsidiary shall not be deemed a
termination of employment, and (b) a Participant who is granted in writing a
leave of absence shall be deemed to have remained in the employ of the Company
or a Subsidiary during such leave of absence.

8.       ADJUSTMENTS

         In the event of any change in the outstanding Common Stock (including
an exchange for cash) by reason of a stock split, reverse stock split, spin-off,
stock dividend, stock combination or reclassification, recapitalization,
reorganization, consolidation, merger, change of control, or similar event, the
Committee shall adjust appropriately the number and kind of Shares subject to
the Plan and available for or covered by Grants and Share prices related to
outstanding Grants, and make such other revisions to outstanding Grants as it
deems are equitably required.

                                   5
<PAGE>

9.       MERGER, CONSOLIDATION, EXCHANGE, ACQUISITION, DISTRIBUTION, LIQUIDATION
         OR DISSOLUTION

         In its sole discretion, and on such terms and conditions as it deems
appropriate, coincident with or after the grant of any Stock Option, the
Committee may provide that such Stock Option cannot be exercised after the
consummation of the merger or consolidation of the Company into another
corporation, the exchange of all or substantially all of the assets of the
Company for the securities of another corporation, the acquisition by another
corporation of 80% or more of the Company's then outstanding shares of voting
stock or the recapitalization, reclassification, liquidation or dissolution of
the Company, or other adjustment or event which results in shares of Common
Stock being exchanged for or converted into cash, securities or other property,
and if the Committee so provides, it shall, on such terms and conditions as it
deems appropriate in its absolute discretion, also provide, either by the terms
of such Stock Option or by a resolution adopted prior to the consummation of
such merger, consolidation, exchange, acquisition, recapitalization,
reclassification, liquidation or dissolution, that, for some period of time
prior to the consummation of such transaction or event, such Stock Option shall
be exercisable as to all shares subject thereto, notwithstanding anything to the
contrary herein (but subject to the provisions of Section 6(b)) and that, upon
the consummation of such event, such Stock Option shall terminate and be of no
further force or effect; provided, however, that the Committee may also provide,
in its absolute discretion, that even if the Stock Option shall remain
exercisable after any such event, from and after such event, any such Stock
Option shall be exercisable only for the kind and amount of cash, securities
and/or other property, or the cash equivalent thereof (net of any applicable
exercise price), receivable as a result of such event by the holder of a number
of shares of stock for which such Stock Option could have been exercised
immediately prior to such event.

         In the event of a "spin-off" or other substantial distribution of
assets of the Company which has a material diminutive effect upon the Fair
Market Value of the Company's Common Stock, the Committee shall in its
discretion make an appropriate and equitable adjustment to any Stock Option
exercise price to reflect such diminution.

10.      AMENDMENT AND TERMINATION

         The Committee shall have the authority to make such amendments to any
terms and conditions applicable to outstanding Grants as are consistent with
this Plan provided that, except for adjustments under Section 8 or 9 hereof, no
such action shall modify such Grant in a manner adverse to the Participant
without the Participant's consent except as such modification is provided for or
contemplated in the terms of the Grant. The Board of Directors may amend,
suspend or terminate the Plan.

11.      WITHHOLDING TAXES

         The Company shall have the right to deduct from any cash payment made
under the Plan any federal, state or local income or other taxes required by law
to be withheld with respect to such payment. It shall be a condition to the
obligation of the Company to deliver Shares upon the exercise of a Stock Option
that the Participant pay to the Company such amount as may be requested by the
Company for the purpose of satisfying any liability for such withholding taxes.
Any Grant Agreement may provide that the Participant may elect, in accordance
with any

                                   6
<PAGE>

conditions set forth in such Grant Agreement, to pay a portion or all of such
withholding taxes in shares of Common Stock (including shares acquired by
contemporaneous exercise of other Stock Options).

12.      REGISTRATION

                  (a) If the Company shall have filed a registration statement
         pursuant to the requirements of Section 12 of the Exchange Act, or
         engaged in a Public Offering (as defined below), (i) the Company shall
         use reasonable efforts to register the Stock Options and the Common
         Stock to be acquired on exercise of the Stock Options on a Form S-8
         Registration Statement or any successor to Form S-8 to the extent that
         such registration is then available with respect to such Stock Options
         and Common Stock and (ii) the Company will use reasonable efforts to
         file the reports required to be filed by it under the Securities Act
         and the Exchange Act and the rules and regulations adopted by the
         Securities and Exchange Commission ("SEC") thereunder, to the extent
         required from time to time to enable the Participant to sell shares of
         Common Stock without registration under the Securities Act within the
         limitations of the exemptions provided under any applicable rule or
         regulation of the SEC. Notwithstanding anything contained in this
         Section 12, the Company may deregister under Section 12 of the Exchange
         Act if it is then permitted to do so pursuant to the Exchange Act and
         the rules and regulations thereunder. Nothing in this Section 12 shall
         be deemed to limit in any manner any otherwise applicable restrictions
         on sales of Common Stock.

                  (b) As used herein the term "Public Offering" shall mean the
         sale of shares of Common Stock to the public pursuant to a registration
         statement under the Securities Act which has been declared effective by
         the SEC (other than a registration statement on Form S-8 or any other
         similar form) which results in an active trading market in the Common
         Stock.

13.      EFFECTIVE DATE AND TERMINATION DATES

         The Plan shall be effective on and as of the date of its approval by
the stockholders of the Company and shall terminate ten years later, subject to
earlier termination by the Board of Directors pursuant to Section 10.

                               * * * * * * * * * *

         I hereby certify that the foregoing Plan was duly adopted by the Board
of Directors of Alliance Imaging, Inc. and approved by the shareholders of the
Company on November 2, 1999. Executed on this ____ day of November, 1999.

                                                   /s/ Russell D. Phillips, Jr.,
                                                   -----------------------------
                                                   Russell D. Phillips, Jr.,
                                                   Secretary

                                          7

<PAGE>

                 FORM OF NON-QUALIFIED STOCK OPTION AGREEMENT

                  This Non-Qualified Stock Option Agreement (this "Agreement"),
is entered into as of November 2, 1999 by and between Alliance Imaging, Inc., a
Delaware corporation hereinafter referred to as the "Company," and            ,
an employee of the Company or a Subsidiary (as defined below) or Affiliate (as
defined below) of the Company, hereinafter referred to as "Optionee."

                  WHEREAS, the Company wishes to afford the Optionee the
opportunity to purchase shares of its $.01 par value Common Stock ("Common
Stock");

                  WHEREAS, the Company wishes to carry out the Plan (as defined
below), the terms of which are hereby incorporated by reference and made a part
of this Agreement; and

                  WHEREAS, the Committee (as defined below) appointed to
administer the Plan has determined that it would be to the advantage and best
interest of the Company and its stockholders to grant the Non-Qualified Stock
Option(s) provided for herein to the Optionee as an incentive for increased
efforts during his term of employment with the Company or its Subsidiaries or
Affiliates, and has advised the Company thereof and instructed the undersigned
officers to issue said Options;

                  NOW, THEREFORE, in consideration of the mutual covenants
herein contained and other good and valuable consideration, receipt of which is
hereby acknowledged, the parties hereto do hereby agree as follows:

                                    ARTICLE I

                                   DEFINITIONS

                  Whenever the following terms are used in this Agreement, they
shall have the meaning specified in the Plan or below unless the context clearly
indicates to the contrary.

SECTION 1.1        - AFFILIATE

                  "Affiliate" shall mean (a) with respect to any Person, any
other Person directly or indirectly controlling, controlled by, or under common
control with, such Person, and (b) with respect to the Company, also any entity
designated by the Board of Directors of the Company in which the Company or one
of its Affiliates has an interest, and (c) with respect to Viewer, Kohlberg
Kravis Roberts & Co., L.P. ("KKR"), and any Affiliate of any partner of KKR. For
purposes of this Agreement, "Person" means an individual, partnership,
corporation, business trust, joint stock company, trust, unincorporated
association, joint venture, governmental

<PAGE>

authority or other entity of whatever nature, and "control" shall have the
meaning given such term under Rule 405 of the Securities Act.

SECTION 1.2        - CAUSE

                  "Cause" shall mean (i) the Optionee's willful refusal to
perform in any material respects the Optionee's lawful duties or
responsibilities for the Company or its Subsidiaries, (ii) the Optionee's
willful disregard in any material respect of any financial or other budgetary
limitations established in good faith by the Company's Board of Directors, (iii)
misconduct by the Optionee that causes material and demonstrable injury,
monetarily or otherwise, to the Company or its Subsidiaries, including but not
limited to misappropriation or conversion of assets of the Company or its
Subsidiaries (other than non-material assets); (iv) conviction of or entry of a
plea of NOLO CONTENDERE to a non-vehicular felony; or (v) the Optionee's
violation of any restrictive covenant contained in any employment agreement to
which he and the Company or one of its Subsidiaries are parties, which violation
constitutes a material breach by Optionee of such agreement. No act or failure
to act by the Optionee shall be deemed "willful" if done, or omitted to be done,
by him in good faith and with the reasonable belief that his action or omission
was in the best interest of the Company or consistent with Company policies or
the directive of the Company's Board of Directors.

SECTION 1.3        - CODE

                  "Code" shall mean the Internal Revenue Code of 1986, as
amended.

SECTION 1.4        - COMMITTEE

                  "Committee" shall mean the Compensation Committee of the Board
of Directors or any other committee of the Board of Directors of the Company
designated to administer the Plan.

SECTION 1.5        - DETERMINATION DATE

                  "Determination Date" means the second December 31 following
the Vesting Reference Date and each of the next four anniversaries thereof.

SECTION 1.6        - OPTIONS

                  "Options" shall mean the Non-Qualified Stock Options, which
may include a Time Option and/or a Performance Option, to purchase Common Stock
granted under this Agreement.

SECTION 1.7        - PERFORMANCE OPTION

                  "Performance Option" shall mean an Option with respect to
which the commencement of exercisability is governed by Section 3.1(b) hereof.

                                       2
<PAGE>

SECTION 1.8        - PERMANENT DISABILITY

                  The Optionee shall be deemed to have a "Permanent Disability"
if the Optionee is unable to engage in the activities required by his employment
by reason of any medically determined physical or mental impairment which can be
expected to result in death or which has lasted or can be expected to last for a
continuous period of not less than 12 months, as reasonably determined by the
Board of Directors of the Company in good faith and in its discretion.

SECTION 1.9       - PERMITTED RETIREMENT

                  "Permitted Retirement" shall mean retirement at age 65 or over
(or such other age as may be approved by the Board of Directors of the Company)
after having been employed by the Company or one of its Subsidiaries or
Affiliates for at least three years after the Vesting Reference Date.

SECTION 1.10       - PLAN

                  "Plan" shall mean the 1999 Equity Plan for Employees of
Alliance Imaging, Inc. and Subsidiaries, as the same may be amended from time
to time.

SECTION 1.11      - PRONOUNS

                  The masculine pronoun shall include the feminine and neuter,
and the singular the plural, where the context so indicates.

SECTION 1.12       - SECRETARY

                  "Secretary" shall mean the Secretary of the Company.

SECTION 1.13       - SECURITIES ACT

                  "Securities Act" means the Securities Act of 1933, as amended
and the rules and regulations promulgated thereunder.

SECTION 1.14       - STOCKHOLDER'S  AGREEMENT

                  "Stockholder's Agreement" shall mean that certain
Stockholder's Agreement dated as of November 2, 1999 by and between the Company,
the Optionee and Viewer.

SECTION 1.15       - SUBSIDIARY

                  "Subsidiary" with respect to any entity shall mean any
corporation in an unbroken chain of corporations beginning with such entity if
each of the corporations, or group of commonly controlled corporations, other
than the last corporation in the unbroken chain, then

                                       3
<PAGE>

owns stock possessing 50% or more of the total combined voting power of all
classes of stock in one of the other corporations in such chain.

SECTION 1.16       - TIME OPTION

                  "Time Option" shall mean an Option with respect to which the
commencement of exercisability is governed by Section 3.1(a) hereof.

SECTION 1.17      - VIEWER

                  "Viewer" shall mean Viewer Holdings LLC, a Delaware limited
liability company.

SECTION 1.18       - VESTING REFERENCE DATE

                  "Vesting Reference Date" shall mean the date of this
Agreement.

                                   ARTICLE II
                                GRANT OF OPTIONS

SECTION 2.1        - GRANT OF OPTIONS

                  For good and valuable consideration, on and as of the date
hereof the Company irrevocably grants to the Optionee a Time Option and/or a
Performance Option to purchase any part or all of an aggregate of the number of
shares set forth with respect to each such Option on the signature page hereof
of its Common Stock upon the terms and conditions set forth in this Agreement.

SECTION 2.2        - EXERCISE PRICE

                  The exercise price of the shares of stock covered by the
Option(s) is set forth on Exhibit A.

SECTION 2.3        - CONSIDERATION TO THE COMPANY

                  In consideration of the granting of these Option(s) by the
Company, the Optionee agrees to render faithful and efficient services to the
Company or one of its Subsidiaries or Affiliates, with such duties and
responsibilities as the Company shall from time to time prescribe. Nothing in
this Agreement or in the Plan shall confer upon the Optionee any right to
continue in the employ of the Company or any of its Subsidiaries or Affiliates
or shall interfere with or restrict in any way the rights of the Company and its
Subsidiaries and Affiliates, which are hereby expressly reserved, to terminate
the employment of the Optionee at any time for any reason whatsoever, with or
without Cause.

                                       4
<PAGE>

SECTION 2.4        - ADJUSTMENTS IN OPTIONS

                  Subject to Section 9 of the Plan, in the event that the
outstanding shares of the stock subject to an Option are, from time to time,
changed into or exchanged for cash or a different number or kind of shares of
the Company or other securities of the Company by reason of a merger,
consolidation, recapitalization, reclassification, stock split, stock dividend,
combination of shares, or otherwise, the Committee shall make an appropriate and
equitable adjustment in the number and kind of shares or other consideration and
the exercise price as to which such Option, or portions thereof then
unexercised, shall be exercisable in order to prevent dilution or enlargement of
the benefits intended to be made available with respect to any Option. Any such
adjustment made by the Committee shall be final and binding upon the Optionee,
the Company and all other interested persons.

                                   ARTICLE III

                            PERIOD OF EXERCISABILITY

SECTION 3.1       - COMMENCEMENT OF EXERCISABILITY

                (a) The Time Option shall become exercisable with respect to 20%
of the shares of Common Stock subject to such Time Option on each anniversary of
the Vesting Reference Date; provided, that notwithstanding the foregoing, the
Time Option shall become exercisable as to 100% of the shares of Common Stock
subject to such Option immediately prior to the consummation of a Change of
Control (but only to the extent such Option has not otherwise terminated);
provided, however, that as a condition subsequent to the acceleration of the
exercisability of the Option pursuant to this paragraph, the Change of Control
shall be consummated. In the event the contemplated Change of Control is not
consummated, the acceleration of exercisability and the exercise, if any, of the
Option shall be void AB INITIO. A "Change of Control" means (i) a sale of all or
substantially all of the assets of the Company to a Person who is not an
Affiliate of Viewer or an entity in which the shareholders of the Company
immediately prior to such transaction do not control more than 50% of the voting
power immediately following the transaction, (ii) a sale by Viewer or any of its
Affiliates resulting in more than 50% of the voting stock of the Company being
held by a Person or Group that does not include Viewer or any of its Affiliates
or (iii) a merger or consolidation of the Company into another Person which is
not an Affiliate of Viewer, if and only if, after such merger or consolidation
Viewer and its Affiliates lose the ability to elect a majority of the Board of
Directors of the Company or the surviving Company. "Group" means two or more
Persons acting together as a partnership, limited partnership, syndicate or
other group for the purpose of acquiring, holding or disposing of securities of
the Company.

                (b) (i) Except as provided in (ii) and (iii) below, the
Performance Option shall be exercisable on the eighth anniversary of the
Vesting Reference Date.

                  (ii) Notwithstanding the foregoing, on each Determination Date
the Performance Option shall become exercisable for an incremental percentage of
the shares of

                                       5
<PAGE>

Common Stock subject to such Option equal to the product of 20% and the
Achievement Ratio for such year, provided that on each Determination Date in no
event shall the total percentage of shares of Common Stock subject to the
Performance Option that are exercisable be less than the product of (A) 20%, (B)
the Achievement Ratio for such Determination Date and (C) the number of
Determination Dates (including such Determination Date) as have fallen from and
after the Vesting Reference Date (but only to the extent such Option has not
otherwise terminated).

                  (iii) Notwithstanding the foregoing, in the event that upon
the consummation of a Change of Control the internal rate of return on its
investment, after giving effect to dilution from the number of shares of Common
Stock issuable upon exercise of all vested stock options and options which will
become vested upon the Change of Control, realized by Viewer is at least equal
to the applicable percentage set forth in Exhibit A for the year in which such
transaction occurs, the Performance Option shall become exercisable as to that
percentage set forth in Exhibit A for such applicable percentage of the shares
of Common Stock subject to such Option immediately prior to the consummation of
a Change of Control (but only to the extent such Option has not otherwise
terminated); provided, however, that as a condition subsequent to the
acceleration of the exercisability of the Option pursuant to this paragraph, the
Change of Control shall be consummated. In the event the contemplated Change of
Control is not consummated, the acceleration of exercisability and the exercise,
if any, of the Option shall be void AB INITIO.

                      (c) For purposes of this Section 3.1 the "Achievement
Ratio" for each fiscal year shall be defined in Exhibit A.

                      (d) Notwithstanding the foregoing, no Option or portion
thereof shall become exercisable as to any additional shares of Common Stock
following the termination of employment of the Optionee for any reason and
any Option which is non-exercisable as of the Optionee's termination of
employment shall be immediately cancelled.

SECTION 3.2        - EXPIRATION OF OPTIONS

                  Except as otherwise provided in Section 5 or 6 of the
Stockholder's Agreement, the Options may not be exercised to any extent by
anyone after the first to occur of the following events:

                  (a) The tenth anniversary of the date hereof; or

                  (b) The first anniversary of the date of the Optionee's
         termination of employment by reason of death, Permanent Disability or
         Permitted Retirement; or

                  (c) The first business day which is fifteen calendar days
         after the earlier of (i) 75 days after termination of employment of the
         Optionee for any reason other than for Cause, death, Permanent
         Disability or Permitted Retirement or (ii) the delivery of notice by
         the Company that it does not intend to exercise its call right under
         Section 6 of the Stockholder's Agreement; PROVIDED, HOWEVER, that in
         any event the Options shall remain exercisable under this subsection
         3.2(c) until at least 45 days after termination of

                                       6
<PAGE>

         employment of the Optionee for any reason other than for death,
         Permanent Disability or Permitted Retirement; or

                  (d) The date the Option is terminated pursuant to Section
         5, 6 or 10(b) of the Stockholder's  Agreement;

                  (e) The opening of business on the date of an Optionee's
         termination of employment by the Company for Cause; or

                  (f) Subject to the provisions for accelerated exercisability
         pursuant to Sections 3.1(a) and (b) upon a Change of Control, if the
         Committee so determines pursuant to Section 9 of the Plan, the
         effective date of either the merger or consolidation of the Company
         into another Person, or the exchange or acquisition by another Person
         of all or substantially all of the Company's assets or 80% or more of
         its then outstanding voting stock, or the recapitalization,
         reclassification, liquidation or dissolution of the Company. At least
         ten (10) days prior to the effective date of such merger,
         consolidation, exchange, acquisition, recapitalization,
         reclassification, liquidation or dissolution, the Committee shall give
         the Optionee notice of such event if the Option has then neither been
         fully exercised nor become unexercisable under this Section 3.2.

                                   ARTICLE IV

                               EXERCISE OF OPTION

SECTION 4.1       - PERSON ELIGIBLE TO EXERCISE

                  During the lifetime of the Optionee, only he may exercise an
Option or any portion thereof. After the death of the Optionee, any exercisable
portion of an Option may, prior to the time when an Option becomes unexercisable
under Section 3.2, be exercised by his personal representative or by any person
empowered to do so under the Optionee's will or under the then applicable laws
of descent and distribution.

SECTION 4.2        - PARTIAL EXERCISE

                  Any exercisable portion of an Option or the entire Option, if
then wholly exercisable, may be exercised in whole or in part at any time prior
to the time when the Option or portion thereof becomes unexercisable under
Section 3.2; provided, however, that any partial exercise shall be for whole
shares of Common Stock only.

SECTION 4.3        - MANNER OF EXERCISE

                  An Option, or any exercisable portion thereof, may be
exercised solely by delivering to the Secretary or his office all of the
following prior to the time when the Option or such portion becomes
unexercisable under Section 3.2:

                                       7
<PAGE>

                  (a) Notice in writing signed by the Optionee or the other
         person then entitled to exercise the Option or portion thereof, stating
         that the Option or portion thereof is thereby exercised, such notice
         complying with all applicable rules established by the Committee;

                  (b) Full payment (in cash, by check or by a combination
         thereof) for the shares with respect to which such Option or portion
         thereof is exercised;

                  (c) A bona fide written representation and agreement, in a
         form satisfactory to the Committee, signed by the Optionee or other
         person then entitled to exercise such Option or portion thereof,
         stating that the shares of stock are being acquired for his own
         account, for investment and without any present intention of
         distributing or reselling said shares or any of them except as may be
         permitted under the Securities Act, and then applicable rules and
         regulations thereunder, and that the Optionee or other person then
         entitled to exercise such Option or portion thereof will indemnify the
         Company against and hold it free and harmless from any loss, damage,
         expense or liability resulting to the Company if any sale or
         distribution of the shares by such person is contrary to the
         representation and agreement referred to above; provided, however, that
         the Committee may, in its absolute discretion, take whatever additional
         actions it deems appropriate to ensure the observance and performance
         of such representation and agreement and to effect compliance with the
         Act and any other federal or state securities laws or regulations;

                  (d) Full payment to the Company (in cash, by check or by a
         combination thereof) of all amounts which, under federal, state or
         local law, it is required to withhold upon exercise of the Option; and

                  (e) In the event the Option or portion thereof shall be
         exercised pursuant to Section 4.1 by any person or persons other than
         the Optionee, appropriate proof of the right of such person or persons
         to exercise the Option.

Without limiting the generality of the foregoing, the Committee may require an
opinion of counsel acceptable to it to the effect that any subsequent transfer
of shares acquired on exercise of an Option does not violate the Securities Act,
and may issue stop-transfer orders covering such shares. Share certificates
evidencing stock issued on exercise of this Option shall bear an appropriate
legend referring to the provisions of subsection (c) above and the agreements
herein. The written representation and agreement referred to in subsection (c)
above shall, however, not be required if the shares to be issued pursuant to
such exercise have been registered under the Securities Act, and such
registration is then effective in respect of such shares.

SECTION 4.4        - CONDITIONS TO ISSUANCE OF STOCK CERTIFICATES

                  The shares of stock deliverable upon the exercise of an
Option, or any portion thereof, may be either previously authorized but unissued
shares or issued shares which have then been reacquired by the Company. Such
shares shall be fully paid and nonassessable. The

                                       8
<PAGE>

Company shall not be required to issue or deliver any certificate or
certificates for shares of stock purchased upon the exercise of an Option or
portion thereof prior to fulfillment of all of the following conditions:

                  (a) The obtaining of approval or other clearance from any
         state or federal or foreign governmental agency which the Committee
         shall, in its absolute discretion, determine to be necessary or
         advisable; and

                  (b) The lapse of such reasonable period of time following the
         exercise of the Option as the Committee may from time to time establish
         for reasons of administrative convenience; provided, however, that no
         delay in the issuance of any certificate to be issued hereunder shall
         operate to prejudice or impair the Optionee's rights to participate in
         a corporate transaction providing for the disposition of stock or to
         exercise his rights under the Stockholder's Agreement.

SECTION 4.5        - RIGHTS AS STOCKHOLDER

                  The holder of an Option shall not be, nor have any of the
rights or privileges of, a stockholder of the Company in respect of any shares
purchasable upon the exercise of the Option or any portion thereof unless and
until certificates representing such shares shall have been issued by the
Company to such holder.

                                    ARTICLE V

                                  MISCELLANEOUS

SECTION 5.1       - ADMINISTRATION

                  The Committee shall have the power to interpret the Plan and
this Agreement and to adopt such rules for the administration, interpretation
and application of the Plan as are consistent therewith and to interpret or
revoke any such rules. All actions taken and all interpretations and
determinations made by the Committee shall be final and binding upon the
Optionee, the Company and all other interested persons. No member of the
Committee shall be personally liable for any action, determination or
interpretation made in good faith with respect to the Plan or the Options. In
its absolute discretion, the Board of Directors may at any time and from time to
time exercise any and all rights and duties of the Committee under the Plan and
this Agreement.

                                       9
<PAGE>

SECTION 5.2        - OPTIONS NOT TRANSFERABLE

                  Neither the Options nor any interest or right therein or part
thereof shall be liable for the debts, contracts or engagements of the Optionee
or his successors in interest or shall be subject to disposition by transfer,
alienation, anticipation, pledge, encumbrance, assignment or any other means
whether such disposition be voluntary or involuntary or by operation of law by
judgment, levy, attachment, garnishment or any other legal or equitable
proceedings (including bankruptcy), and any attempted disposition thereof shall
be null and void and of no effect; provided, however, that this Section 5.2
shall not prevent transfers by will or by the applicable laws of descent and
distribution.

SECTION 5.3        - SHARES TO BE RESERVED

                  The Company shall at all times during the term of the Options
reserve and keep available such number of shares of stock as will be sufficient
to satisfy the requirements of this Agreement.

SECTION 5.4        - NOTICES

                  Any notice to be given under the terms of this Agreement to
the Company shall be addressed to the Company in care of its Secretary, and any
notice to be given to the Optionee shall be addressed to him at his most recent
address as reflected in the Company's records. By a notice given pursuant to
this Section 5.4, either party may hereafter designate a different address for
notices to be given to him or it. Any notice which is required to be given to
the Optionee shall, if the Optionee is then deceased, be given to the Optionee's
personal representative if such representative has previously informed the
Company of his status and address by written notice under this Section 5.4. Any
notice shall have been deemed duly given when enclosed in a properly sealed
envelope or wrapper addressed as aforesaid, and delivered by hand (whether by
courier or otherwise) or sent by registered or certified mail, return receipt
requested (with postage prepaid).

SECTION 5.5        - TITLES

                  Titles are provided herein for convenience only and are not to
serve as a basis for interpretation or construction of this Agreement.

SECTION 5.6        - APPLICABILITY OF PLAN AND STOCKHOLDER'S  AGREEMENT

                  The Options and the shares of Common Stock issued to the
Optionee upon exercise of the Options shall be subject to all of the terms and
provisions of the Plan and the Stockholder's Agreement, to the extent applicable
to the Options and such shares. In the event of any conflict between this
Agreement and the Plan, the terms of the Plan shall control. In the event of any
conflict between this Agreement or the Plan and the Stockholder's Agreement, the
terms of the Stockholder's Agreement shall control.

                                       10
<PAGE>

SECTION 5.7        - AMENDMENT

                  This Agreement may be amended only by a writing executed by
the parties hereto, which specifically states that it is amending this
Agreement.

SECTION 5.8        - GOVERNING LAW

                  The laws of the State of Delaware shall govern the
interpretation, validity and performance of the terms of this Agreement
regardless of the law that might be applied under principles of conflicts of
laws.

SECTION 5.9        - JURISDICTION

                  Any suit, action or proceeding against the Optionee with
respect to this Agreement, or any judgment entered by any court in respect of
any thereof, may be brought in any court of competent jurisdiction in the State
of Delaware, and the Optionee hereby submits to the non-exclusive jurisdiction
of such courts for the purpose of any such suit, action, proceeding or judgment.
The Optionee hereby irrevocably waives any objections which he may now or
hereafter have to the laying of the venue of any suit, action or proceeding
arising out of or relating to this Agreement brought in any court of competent
jurisdiction in the State of Delaware, and hereby further irrevocably waives any
claim that any such suit, action or proceeding brought in any such court has
been brought in any inconvenient forum. No suit, action or proceeding against
the Company with respect to this Agreement may be brought in any court, domestic
or foreign, or before any similar domestic or foreign authority other than in a
court of competent jurisdiction in the State of Delaware, and the Optionee
hereby irrevocably waives any right which he may otherwise have had to bring
such an action in any other court, domestic or foreign, or before any similar
domestic or foreign authority. The Company hereby submits to the jurisdiction of
such courts for the purpose of any such suit, action or proceeding.

                                       11
<PAGE>

                  IN WITNESS WHEREOF, this Non-Qualified Stock Option Agreement
has been executed and delivered by the parties hereto as of the date first
written above.

NAME, OPTIONEE                         ALLIANCE IMAGING, INC.

                                       By
---------------------------------        --------------------------------------
Signature                              Its
                                          -------------------------------------

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

---------------------------------
       Optionee's Address

Aggregate number of shares of Common Stock
for which the Time Option granted hereunder is exercisable:

Aggregate number of shares of Common Stock for which
the Performance Option granted hereunder is exercisable:

                                       12
<PAGE>

                                    EXHIBIT A

1.   EXERCISE PRICE. The per share exercise price for the Option shall be the
     "Initial Price Per Share" as defined in the Stockholder's Agreement,
     without commission or other charge.

2.   SECTION 3.1 DEFINITIONS.

A.   Section 3.1(c)

          (i) The "Achievement Ratio" for a fiscal year shall be determined on
     the basis of the value of the Performance Metric for such year as compared
     to the Performance Targets described below. For values of the Performance
     Metric between the amounts indicated for Achievement Ratios of 50% and
     100%, the Achievement Ratio shall be determined by linear interpolation.
     For values of the Performance Metric below the amount indicated for an
     Achievement Ratio of 50%, the Achievement Ratio shall be zero.

          (ii) "Performance Metric" means the "Equity Value" per "Fully Diluted
     Share" of the Company. For this purpose,

               (A) "Equity Value" for a Company fiscal year shall be equal to
          (x) 6.5 times the sum of (1) the Company's earnings (including, in the
          case of business operations acquired by the Company during a fiscal
          period, the pro-forma earnings (as reasonably determined by, or at the
          direction of, the Board of Directors of the Company) of such
          operations for the portion of such period as falls prior to the
          acquisition) for such year before interest, taxes, depreciation and
          amortization (2) any management fees paid in such year to KKR and (3)
          legal, accounting and other similar direct, one-time expenses related
          to (a) the transactions effectuated by the "Merger Agreement" as
          defined in the Stockholder's Agreement, (b) the "American Shared" and
          "SMT" transactions and (c) other transactions deemed to be similar by
          the Board of Directors of the Company, minus (y) the Company's net
          debt (including preferred stock and capitalized leases); and

               (B) the Company's Fully Diluted Shares shall be the sum of (x)
          the number of the Company's shares of Common Stock outstanding upon
          consummation of the transactions contemplated by the Agreement and
          Plan of Merger between Viewer Acquisition Corp. and Alliance Imaging,
          Inc. dated September 13, 1999 (the "Closing") and (y) the number of
          shares of Common Stock issuable upon the exercise of all stock options
          and other dilutive rights to acquire Common Stock which are
          outstanding as of the Closing and the conversion of all dilutive
          securities convertible into Common Stock which are outstanding as of
          the Closing, PROVIDED, HOWEVER, that the number of such shares of
          Common Stock shall not include Common Stock issuable upon the exercise
          of stock options granted in connection with the Closing.

          (iii) The "Performance Target" for each fiscal year shall be as set
     forth below; provided, that to the extent that the Company issues Common
     Stock other than pursuant to exercise of Options or engages in a leveraged
     recapitalization or other

<PAGE>

     transaction of similar effect, the Board of Directors of the Company will
     adjust the Performance Target to account therefor.

     Performance Targets: Values of Performance Metric for Achievement Ratio
     Target:*

<TABLE>
<CAPTION>
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
                                    2000              2001             2002              2003               2004
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
<S>                           <C>               <C>               <C>              <C>                <C>
   100% Achievement Ratio          $82.54           $131.57           $185.36          $247.69            $292.70
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
   50% Achievement Ratio             **             $124.53           $168.27          $217.68            $245.59
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
</TABLE>

*Includes all shares and options outstanding at Closing. Does not include new
options granted in connection with Closing.

** No vesting in the year 2000 for values of Performance Metric below 100%
Achievement Ratio.

B.       Internal Rates of Return for Acceleration of Option Vesting Upon Change
in Control under Section 3.1(b)(iii):

<TABLE>
<CAPTION>
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
                                    2000              2001             2002              2003               2004
                                                                                                       and thereafter
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
<S>                           <C>               <C>               <C>              <C>                 <C>
 100% applicable percentage         35%*             40%**             40%**            40%**               35%*
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
 50% applicable percentage                           35%**             35%**            35%**
----------------------------- ----------------- ----------------- ---------------- ----------------- -------------------
</TABLE>

* No accelerated vesting for internal rate of return below 35%.

** Linear interpolation for internal rates of return between 35 and 40%.

<PAGE>

                                    FORM OF
                               FIRST AMENDMENT TO
                      NON-QUALIFIED STOCK OPTION AGREEMENT

         This First Amendment to Non-Qualified Stock Option Agreement is entered
into as of the ______ day of June, 2001 by and between Alliance Imaging, Inc., a
Delaware corporation, hereinafter referred to as the "Company," and
_________________, an employee of the Company, hereinafter referred to as
"Optionee."

         WHEREAS, the Company and Optionee have entered into a Non-Qualified
Stock Option Agreement dated as of November 2, 1999, hereinafter referred to as
the "Option Agreement";

         WHEREAS, pursuant to Section 5.7 of the Option Agreement, the Option
Agreement may only be amended in a writing executed by both parties, which
specifically states that it is amending the Option Agreement;

         WHEREAS, the Company and Optionee mutually desire to amend the Option
Agreement as set forth in this First Amendment to Non-Qualified Stock Option
Agreement;

         NOW, THEREFORE, the parties hereto do hereby agree to amend the Option
Agreement effective June 20, 2001 as follows:

         1. By substituting the following for the definition of Determination
Date contained in Section 1.5 of the Option Agreement:

                  "Determination Date" means the third December 31 following
         the Vesting Reference Date and each of the next three anniversaries
         thereof.

         2. By substituting the following for Section 3.1(b)(ii) of the Option
Agreement:

                  "(ii) Notwithstanding the foregoing, on each Determination
         Date the Performance Option shall become exercisable for 25% of the
         shares of Common Stock subject to such Option if the Performance Metric
         equals or exceeds the Performance Target for such year, provided that
         on any such Determination Date in no event shall the total percentage
         of shares of Common Stock subject to the Performance Option that are
         exercisable be less than the product of (A) 25% and (B) the number of
         Determination Dates (including such Determination Date) as have fallen
         from and after the Vesting Reference Date (but only to the extent such
         Option has not otherwise terminated)."

         3. By substituting the following for Section 3.1(c) of the Option
Agreement:

                  "For purposes of this Section 3.1 the "Performance Metric" and
         the "Performance Target" for each fiscal year shall be defined in
         Exhibit A."

         4. By reducing the aggregate number of shares of Common Stock for which
the Performance Option is exercisable as set forth on the signature page of the
Option Agreement by 20%.

<PAGE>

         5. By substituting the Exhibit A attached hereto for Exhibit A to the
Option Agreement.

                  IN WITNESS WHEREOF, this First Amendment to Non-Qualified
Stock Option Agreement has been executed and delivered by the parties hereto as
of the date first written above.

                                       OPTIONEE

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

                                       Name:
                                            ------------------------------------

                                       ALLIANCE IMAGING, INC.

                                       By:
                                          --------------------------------------

                                       Its:
                                           -------------------------------------

                                       2
<PAGE>

                                    EXHIBIT A
                                  (AS AMENDED)

         1. EXERCISE PRICE. The per share exercise price for the Option shall be
the "Initial Price Per Share" as defined in the Stockholder's Agreement, without
commission or other charge.

         2. SECTION 3.1 DEFINITIONS.

                  A. Section 3.1(c)

                           (i) "Performance Metric" for a Company fiscal year
                  shall be equal to the quotient of (I) (x) 6.5 times the sum of
                  (1) the Company's earnings (including in the case of business
                  operations acquired by the Company during a fiscal period, the
                  pro-forma earnings (as reasonably determined by, or at the
                  direction of, the Board of Directors of the Company) of such
                  operations for the portion of such period as falls prior to
                  the acquisition) for such year before interest, taxes,
                  depreciation and amortization, as adjusted in the reasonable
                  determination of the Board of Directors of the Company for any
                  unusual non-operating and/or non-cash items not included in
                  the Company's financial statements for fiscal year 2001 (2)
                  any management fees paid in such year to KKR and (3) legal,
                  accounting and other similar direct, one-time expenses related
                  to (a) the transactions effectuated by the "Merger Agreement"
                  as defined in the Stockholder's Agreement, (b) the "American
                  Shared" and "SMT" transactions and (c) other transactions
                  deemed to be similar by the Board of Directors of the Company,
                  minus (y) the Company's net debt (including preferred stock
                  and capitalized leases) as adjusted for any unusual or other
                  items which in the reasonable determination of the Board of
                  Directors of the Company require adjustment, divided by (II)
                  the sum of (x) the shares of the Company's Common Stock
                  outstanding on June 20, 2001 and (y) any shares of Common
                  Stock issued by the Company (other than shares issued pursuant
                  to the exercise of Options) for consideration in an
                  acquisition or pursuant to an offering of its Common Stock to
                  the public, as adjusted for any events or issuances that in
                  the reasonable determination of the Board of Directors of the
                  Company may require adjustment.

                           (ii) The "Performance Target" for each fiscal year
                  shall be as set forth below; provided, that to the extent that
                  the Company issues Common Stock other than pursuant to
                  exercise of Options or engages in a leveraged recapitalization
                  or other transaction of similar effect, then the Board of
                  Directors of the Company will adjust the Performance Target to
                  account therefor.

<TABLE>
<CAPTION>
------------------- ---------------- ----------------- -------------------
       2001              2002              2003               2004
------------------- ---------------- ----------------- -------------------
<S>                 <C>              <C>               <C>
      103.61            133.92            165.92             200.71
------------------- ---------------- ----------------- -------------------
</TABLE>

                  B. Internal Rates of Return for Acceleration of Option Vesting
         Upon Change in Control under Section 3.1(b)(iii):

<PAGE>

<TABLE>
<CAPTION>
--------------------------------- ------------------- -------------------- ------------------ ----------------------
                                         2001                2002                2003                 2004
                                                                                                 and thereafter
--------------------------------- ------------------- -------------------- ------------------ ----------------------
<S>                               <C>                 <C>                  <C>                <C>
   100% applicable percentage           40%**                40%**               40%**                35%*
--------------------------------- ------------------- -------------------- ------------------ ----------------------
   50% applicable percentage            35%**                35%**               35%**
--------------------------------- ------------------- -------------------- ------------------ ----------------------
</TABLE>

* No accelerated vesting for internal rate of return below 35%.

** Linear interpolation for internal rates of return between 35 and 40%.

                                       4
<PAGE>

                                    FORM OF
                               FIRST AMENDMENT TO
                      NON-QUALIFIED STOCK OPTION AGREEMENT

         This First Amendment to Non-Qualified Stock Option Agreement is entered
into as of the ______ day of June, 2001 by and between Alliance Imaging, Inc., a
Delaware corporation, hereinafter referred to as the "Company," and
_________________________, an employee of the Company, hereinafter referred to
as "Optionee."

         WHEREAS, the Company and Optionee have entered into a Non-Qualified
Stock Option Agreement dated as of ______________________, hereinafter referred
to as the "Option Agreement";

         WHEREAS, pursuant to Section 5.7 of the Option Agreement, the Option
Agreement may only be amended in a writing executed by both parties, which
specifically states that it is amending the Option Agreement;

         WHEREAS, the Company and Optionee mutually desire to amend the Option
Agreement as set forth in this First Amendment to Non-Qualified Stock Option
Agreement;

         NOW, THEREFORE, the parties hereto do hereby agree to amend the Option
Agreement effective as of June 20, 2001 as follows:

         1. By substituting the following for Section 3.1(b)(ii) of the Option
Agreement:

                  "(ii) Notwithstanding the foregoing, on each Determination
         Date the Performance Option shall become exercisable for 20% of the
         shares of Common Stock subject to such Option if the Performance Metric
         equals or exceeds the Performance Target for such year, provided that
         on any such Determination Date in no event shall the total percentage
         of shares of Common Stock subject to the Performance Option that are
         exercisable be less than the product of (A) 20% and (B) the number of
         Determination Dates (including such Determination Date) as have fallen
         from and after the Vesting Reference Date (but only to the extent such
         Option has not otherwise terminated)."

         2. By substituting the following for Section 3.1(c) of the Option
Agreement:

                  "For purposes of this Section 3.1 the "Performance Metric" and
         the "Performance Target" for each fiscal year shall be defined in
         Exhibit A."

         3. By substituting the Exhibit A attached hereto for Exhibit A to the
Option Agreement.

<PAGE>

         IN WITNESS WHEREOF, this First Amendment to Non-Qualified Stock Option
Agreement has been executed and delivered by the parties hereto as of the date
first written above.

                                       OPTIONEE

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

                                       Name:
                                            ------------------------------------

                                       ALLIANCE IMAGING, INC.

                                       By:
                                          --------------------------------------

                                       Its:
                                           -------------------------------------

                                       2
<PAGE>

                                    EXHIBIT A
                                  (AS AMENDED)

         1. EXERCISE PRICE. The per share exercise price for the Option shall be
the "Initial Price Per Share" as defined in the Stockholder's Agreement, without
commission or other charge.

         2. SECTION 3.1 DEFINITIONS.

                  A. Section 3.1(c)

                           (i) "Performance Metric" for a Company fiscal year
                  shall be equal to the quotient of (I) (x) 6.5 times the sum of
                  (1) the Company's earnings (including in the case of business
                  operations acquired by the Company during a fiscal period, the
                  pro-forma earnings (as reasonably determined by, or at the
                  direction of, the Board of Directors of the Company) of such
                  operations for the portion of such period as falls prior to
                  the acquisition) for such year before interest, taxes,
                  depreciation and amortization, as adjusted in the reasonable
                  determination of the Board of Directors of the Company for any
                  unusual non-operating and/or non-cash items not included in
                  the Company's financial statements for fiscal year 2001 (2)
                  any management fees paid in such year to KKR and (3) legal,
                  accounting and other similar direct, one-time expenses related
                  to (a) the transactions effectuated by the "Merger Agreement"
                  as defined in the Stockholder's Agreement, (b) the "American
                  Shared" and "SMT" transactions and (c) other transactions
                  deemed to be similar by the Board of Directors of the Company,
                  minus (y) the Company's net debt (including preferred stock
                  and capitalized leases) as adjusted for any unusual or other
                  items which in the reasonable determination of the Board of
                  Directors of the Company require adjustment, divided by (II)
                  the sum of (x) the shares of the Company's Common Stock
                  outstanding on June 20, 2001 and (y) any shares of Common
                  Stock issued by the Company (other than shares issued pursuant
                  to the exercise of Options) for consideration in an
                  acquisition or pursuant to an offering of its Common Stock to
                  the public, as adjusted for any events or issuances that in
                  the reasonable determination of the Board of Directors of the
                  Company may require adjustment.

                           (ii) The "Performance Target" for each fiscal year
                  shall be as set forth below; provided, that to the extent that
                  the Company issues Common Stock other than pursuant to
                  exercise of Options or engages in a leveraged recapitalization
                  or other transaction of similar effect, then the Board of
                  Directors of the Company will adjust the Performance Target to
                  account therefor.

<TABLE>
<CAPTION>
----------------------- ------------------ ------------------ ----------------- ---------------------
         2001                 2002               2003               2004                2005
----------------------- ------------------ ------------------ ----------------- ---------------------
<S>                     <C>                <C>                <C>               <C>
        103.61               133.92             165.92             200.71                239.51
----------------------- ------------------ ------------------ ----------------- ---------------------
</TABLE>

                  B. Internal Rates of Return for Acceleration of Option Vesting
         Upon Change in Control under Section 3.1(b)(iii):

<PAGE>

<TABLE>
<CAPTION>
---------------------- -------------- ---------------- -------------- ----------------------
                           2001            2002            2003               2004
                                                                         and thereafter
---------------------- -------------- ---------------- -------------- ----------------------
<S>                    <C>            <C>              <C>            <C>
   100% applicable         40%**           40%**           40%**              35%*
     percentage
---------------------- -------------- ---------------- -------------- ----------------------
   50% applicable          35%**           35%**           35%**
     percentage
---------------------- -------------- ---------------- -------------- ----------------------
</TABLE>

* No accelerated vesting for internal rate of return below 35%.

** Linear interpolation for internal rates of return between 35 and 40%.

                                       4

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