<PAGE>

                                                                     Exhibit 4.1

                           CELL THERAPEUTICS, INC.,
                                   as Issuer


           STATE STREET BANK AND TRUST COMPANY OF CALIFORNIA, N.A.,
                        a national banking association,
                                  as Trustee



                                   INDENTURE


                           Dated as of June 13, 2001






                 5.75% CONVERTIBLE SUBORDINATED NOTES DUE 2008
<PAGE>

                               TABLE OF CONTENTS
                               -----------------

<TABLE>
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                                                                                                          PAGE
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<S>                                                                                                       <C>
ARTICLE ONE 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.............................................   12
     SECTION 1.4  Acts of Holders of Securities..........................................................   13
     SECTION 1.5  Notices, Etc., to Trustee and Company..................................................   14
     SECTION 1.6  Notice to Holders of Securities; Waiver................................................   15
     SECTION 1.7  Effect of Headings and Table of Contents...............................................   15
     SECTION 1.8  Successors and Assigns.................................................................   16
     SECTION 1.9  Separability Clause....................................................................   16
     SECTION 1.10  Benefits of Indenture.................................................................   16
     SECTION 1.11  Governing Law.........................................................................   16
     SECTION 1.12  Legal Holidays........................................................................   16
     SECTION 1.13  Conflict with Trust Indenture Act.....................................................   17
     SECTION 1.14  Counterparts..........................................................................   17
ARTICLE TWO THE SECURITIES...............................................................................   17
     SECTION 2.1  Form Generally.........................................................................   17
     SECTION 2.2  Title and Terms........................................................................   18
     SECTION 2.3  Denominations..........................................................................   19
     SECTION 2.4  Execution, Authentication, Delivery and Dating.........................................   19
     SECTION 2.5  Global Securities; Temporary Securities................................................   19
     SECTION 2.6  Registration, Registration of Transfer and Exchange;
                   Restrictions on Transfer..............................................................   21
     SECTION 2.7  Mutilated, Destroyed, Lost or Stolen Securities........................................   23
     SECTION 2.8  Payment of Interest; Interest Rights Preserved.........................................   24
     SECTION 2.9  Persons Deemed Owners..................................................................   25
     SECTION 2.10  Cancellation..........................................................................   25
     SECTION 2.11  Computation of Interest...............................................................   26
</TABLE>

                                      -i-
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<TABLE>
<S>                                                                                                         <C>
     SECTION 2.12  CUSIP Numbers.........................................................................   26
ARTICLE THREE SATISFACTION AND DISCHARGE.................................................................   26
     SECTION 3.1  Satisfaction and Discharge of Indenture................................................   26
     SECTION 3.2  Application of Trust Money.............................................................   28
ARTICLE FOUR REMEDIES...................................................................................    28
     SECTION 4.1  Events of Default......................................................................   28
     SECTION 4.2  Acceleration of Maturity; Rescission and Annulment.....................................   29
     SECTION 4.3  Collection of Indebtedness and Suits for Enforcement by Trustee........................   30
     SECTION 4.4  Trustee May File Proofs of Claim.......................................................   31
     SECTION 4.5  Trustee May Enforce Claims without Possession of Securities............................   32
     SECTION 4.6  Application of Money Collected.........................................................   32
     SECTION 4.7  Limitation on Suits....................................................................   32
     SECTION 4.8  Unconditional Right of Holders to Receive Principal,
                   Premium and Interest and to Convert...................................................   33
     SECTION 4.9  Restoration of Rights and Remedies.....................................................   33
     SECTION 4.10  Rights and Remedies Cumulative........................................................   33
     SECTION 4.11  Delay or Omission Not Waiver..........................................................   34
     SECTION 4.12  Control by Holders of Securities......................................................   34
     SECTION 4.13  Waiver of Past Defaults...............................................................   34
     SECTION 4.14  Undertaking for Costs.................................................................   35
     SECTION 4.15  Waiver of Stay, Usury or Extension Laws...............................................   35
ARTICLE FIVE THE TRUSTEE.................................................................................   35
     SECTION 5.1  Certain Duties and Responsibilities....................................................   35
     SECTION 5.2  Notice of Defaults.....................................................................   36
     SECTION 5.3  Certain Rights of Trustee..............................................................   37
     SECTION 5.4  Not Responsible for Recitals or Issuance of Securities.................................   38
     SECTION 5.5  May Hold Securities, Act as Trustee under Other Indentures.............................   38
     SECTION 5.6  Money Held in Trust....................................................................   38
     SECTION 5.7  Compensation and Reimbursement.........................................................   38
     SECTION 5.8  Corporate Trustee Required; Eligibility................................................   39
     SECTION 5.9  Resignation and Removal; Appointment of Successor......................................   39
</TABLE>

                                     -ii-

<PAGE>

<TABLE>
<S>                                                                                                         <C>
     SECTION 5.10  Acceptance of Appointment by Successor................................................   40
     SECTION 5.11  Merger, Conversion, Consolidation or Succession to Business...........................   41
     SECTION 5.12  Authenticating Agents.................................................................   41
     SECTION 5.13  Disqualification; Conflicting Interests...............................................   42
     SECTION 5.14  Preferential Collection of Claims Against Company.....................................   43
ARTICLE SIX CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE.........................................   43
     SECTION 6.1  Company May Consolidate, Etc., Only on Certain Terms...................................   43
     SECTION 6.2  Successor Substituted..................................................................   43
ARTICLE SEVEN SUPPLEMENTAL INDENTURES....................................................................   44
     SECTION 7.1  Supplemental Indentures without Consent of Holders of Securities.......................   44
     SECTION 7.2  Supplemental Indentures with Consent of Holders of Securities..........................   45
     SECTION 7.3  Execution of Supplemental Indentures...................................................   46
     SECTION 7.4  Effect of Supplemental Indentures......................................................   46
     SECTION 7.5  Reference in Securities to Supplemental Indentures.....................................   46
     SECTION 7.6  Notice of Supplemental Indentures......................................................   47
ARTICLE EIGHT COVENANTS..................................................................................   47
     SECTION 8.1  Payment of Principal, Premium and Interest.............................................   47
     SECTION 8.2  Maintenance of Offices or Agencies.....................................................   47
     SECTION 8.3  Money for Security Payments to Be Held in Trust........................................   48
     SECTION 8.4  Existence..............................................................................   49
     SECTION 8.5  Statement by Officers as to Default....................................................   49
     SECTION 8.6  Delivery of Certain Information........................................................   49
ARTICLE NINE REDEMPTION OF SECURITIES....................................................................   50
     SECTION 9.1  Right of Redemption....................................................................   50
     SECTION 9.2  Applicability of Article...............................................................   50
     SECTION 9.3  Election to Redeem; Notice to Trustee..................................................   50
     SECTION 9.4  Selection by Trustee of Securities to Be Redeemed......................................   50
     SECTION 9.5  Notice of Redemption...................................................................   51
     SECTION 9.6  Deposit of Redemption Price............................................................   51
     SECTION 9.7  Securities Payable on Redemption Date..................................................   52
</TABLE>

                                     -iii-
<PAGE>

<TABLE>
<S>                                                                                                         <C>
     SECTION 9.8  Securities Redeemed in Part............................................................   52
     SECTION 9.9  Conversion Arrangement on Call for Redemption..........................................   53
ARTICLE TEN CONVERSION OF SECURITIES.....................................................................   53
     SECTION 10.1  Conversion Privilege and Conversion Rate..............................................   53
     SECTION 10.2  Exercise of Conversion Privilege......................................................   54
     SECTION 10.3  Fractions of Shares...................................................................   55
     SECTION 10.4  Adjustment of Conversion Rate.........................................................   55
     SECTION 10.5  Notice of Adjustments of Conversion Rate..............................................   61
     SECTION 10.6  Notice of Certain Corporate Action....................................................   61
     SECTION 10.7  Company to Reserve Common Stock.......................................................   62
     SECTION 10.8  Taxes on Conversions..................................................................   62
     SECTION 10.9  Covenant as to Common Stock...........................................................   62
     SECTION 10.10  Cancellation of Converted Securities.................................................   63
     SECTION 10.11  Provision in Case of Consolidation, Merger or Sale of Assets.........................   63
     SECTION 10.12  Responsibility of Trustee for Conversion Provisions..................................   64
ARTICLE ELEVEN SUBORDINATION OF SECURITIES...............................................................   64
     SECTION 11.1  Securities Subordinate to Senior Debt.................................................   64
     SECTION 11.2  No Payments in Certain Circumstances;
                     Payment Over of Proceeds Upon Dissolution, Etc......................................   64
     SECTION 11.3  Trustee to Effectuate Subordination...................................................   66
     SECTION 11.4  No Waiver of Subordination Provisions.................................................   66
     SECTION 11.5  Notice to Trustee.....................................................................   67
     SECTION 11.6  Reliance on Judicial Order or Certificate of Liquidating Agent........................   68
     SECTION 11.7  Trustee Not Fiduciary for Holders of Senior Debt......................................   68
     SECTION 11.8  Reliance by Holders of Senior Debt on Subordination Provisions........................   68
     SECTION 11.9  Rights of Trustee as Holder of Senior Debt;
                     Preservation of Trustee's Rights....................................................   68
     SECTION 11.10  Article Applicable to Paying Agents..................................................   69
     SECTION 11.11  Certain Conversions and Repurchases Deemed Payment...................................   69
ARTICLE TWELVE REPURCHASE OF SECURITIES AT THE OPTION OF THE HOLDER UPON A CHANGE IN CONTROL.............   70
</TABLE>

                                     -iv-
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<TABLE>
<S>                                                                                                         <C>
     SECTION 12.1  Right to Require Repurchase...........................................................   70
     SECTION 12.2  Conditions to the Company's Election to Pay the Repurchase
                     Price in Common Stock...............................................................   71
     SECTION 12.3  Notices; Method of Exercising Repurchase Right, Etc...................................   71
ARTICLE THIRTEEN HOLDERS LISTS AND REPORTS BY TRUSTEE AND COMPANY; NON-RECOURSE.........................    74
     SECTION 13.1  Company to Furnish Trustee Names and Addresses of Holders.............................   74
     SECTION 13.2  Preservation of Information...........................................................   74
     SECTION 13.3  No Recourse Against Others............................................................   75
     SECTION 13.4  Reports by Trustee....................................................................   75
     SECTION 13.5  Reports by Company....................................................................   75
</TABLE>

                                      -v-
<PAGE>

     INDENTURE, dated as of June 13, 2001, between Cell Therapeutics, Inc., a
corporation duly organized and existing under the laws of the State of
Washington, having its principal office at 201 Elliott Avenue West, Suite 400,
Seattle, Washington 98119 (herein called the "Company"), and State Street Bank
                                              -------
and Trust Company of California, N.A., a national banking association, as
Trustee hereunder (herein called the "Trustee").
                                      -------

                            RECITALS OF THE COMPANY

     The Company has duly authorized the creation of an issue of its 5.75%
Convertible Subordinated Notes due 2008 (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 shares of 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.

     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 ONE

                       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:

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

     (b)  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

     (c)  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.

                                      -1-
<PAGE>

         "Act," when used with respect to any Holder of a Security, 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.

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

         "aggregate current market price" has the meaning specified in Section
          ------------------------------
10.4(e).

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

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

         "Average Sales Price Per Share" means, with respect to the Common Stock
          -----------------------------
of the Company, for any day, (1) the average of the high and low sales price per
share regular way on a national securities exchange or, (2) if the Common Stock
is not listed on a national securities exchange, the average of the high and low
sales price per share regular way on The Nasdaq National Market, or (3) 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 high and low
sales 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.

         "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, Place
          ------------
of Conversion or any other place, as the case may be, means each Monday,
Tuesday, Wednesday, Thursday and Friday that is not a day on which banking
institutions in such Place of Payment, Place of Conversion or other place, as
the case may be, are authorized or obligated by law or executive 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 9.6 or Section 10.5.
                               -----------    ------------

                                      -2-
<PAGE>

         "Cash Equivalents" means (1) securities issued or directly and fully
          ----------------
guaranteed or insured by the United States government or any agency or
instrumentality thereof (provided that the full faith and credit of the United
States is pledged in support thereof) having maturities of not more than six
months from the date of acquisition, (2) certificates of deposit and eurodollar
time deposits with maturities of six months or less from the date of
acquisition, bankers' acceptances with maturities not exceeding six months and
overnight bank deposits, in each case with any domestic commercial bank having
capital and surplus in excess of $500 million and a Thompson Bank Watch Rating
of "B" or better, (3) repurchase obligations with a term of not more than seven
days for underlying securities of the types described in clause (1) above
entered into with any financial institution meeting the qualifications specified
in clause (2) above, (4) commercial paper having the highest rating obtainable
from Moody's Investors Service, Inc. or Standard & Poor's Ratings Services and
in each case maturing within six months after the date of acquisition and (5)
money market funds at least 95% of the assets of which constitute Cash
Equivalents of the kinds described in clauses (1)-(4) of this definition.

         "Change in Control" means the occurrence at any time, after the
          -----------------
original issuance of the Securities, of any of the following events:

                  (1) the acquisition by any Person (including any syndicated
         group that would be deemed to be a "person" under Section 13(d) (3) of
         the Exchange Act) 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 more than 50% 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 or any employee benefit plan of the Company; or

                  (2) any Person shall succeed in having sufficient of its
         nominees (who are not supported by a majority of the then current Board
         of Directors of the Company) elected to the Board of Directors of the
         Company such that such nominees, when added to any existing directors
         remaining on the Board of Directors of the Company after such election
         who are Affiliates of or acting in concert with any such Person, shall
         constitute a majority of the Board of Directors of the Company; or

                  (3) any consolidation or merger of the Company with or into
         any other Person, or any merger of another Person with or into the
         Company (other than (A) a merger (i) that does not result in any
         reclassification, conversion, exchange or cancellation of outstanding
         shares of the Company's capital stock and (ii) pursuant to which
         holders of Common Stock immediately prior to such transaction have,
         directly or indirectly, 50% or more of the total voting power of all
         shares of capital stock or other ownership interests entitled to vote
         generally in the election of directors of the continuing or surviving
         Person immediately after such transaction and (B) any merger that 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 solely into shares of common stock
         of the Company or another Person); or

                                      -3-
<PAGE>

                  (4) any conveyance, transfer, sale, lease or other disposition
         of all or substantially all of the Company's assets to another Person;

provided, however, that a Change in Control shall not be deemed to have occurred
if the Average Sales Price Per Share on any five Trading Days within (A) 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 (1) above but
not clause (2) or (3) above) or (B) the period of 10 consecutive Trading Days
ending immediately prior to the date of the Change in Control (in the case of a
Change in Control under clause (2) or (3) above) shall, in either case, equal or
exceed 105% of the Conversion Price of the Securities in effect on each such
Trading Day. For the purposes of this definition, "beneficial owner," has the
meaning attributed to it in Rules 13d-3 under the Exchange Act, whether or not
applicable.

         "Code" has the meaning specified in Section 2.1.
          ----                               -----------

         "combined cash and tender amount" has the meaning specified in Section
          -------------------------------                               -------
10.4(e).
-------

         "combined tender and cash amount" has the meaning specified in Section
          -------------------------------                               -------
10.4(f).
-------

         "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 shares of the class designated as common stock
          ------------
of the Company at the date of this Indenture or as such stock may be
reconstituted from time to time. Subject to the provisions of Section 10.11,
                                                              -------------
shares issuable on conversion 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 that the total number of shares of such class
resulting from all such reclassifications bears to the total number of shares of
all such classes resulting from all such reclassifications.

         "Company" means the 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 12.3(a).
          --------------                               ---------------

         "Company Request" or "Company Order" means a written request or order
          ---------------      -------------
signed in the name of the Company by its Chairman of the Board, its Vice
Chairman of the Board, its Chief Executive Officer, its President or a Vice
President, and by its principal financial officer,

                                      -4-
<PAGE>

Treasurer, an Assistant Treasurer, its Secretary or an Assistant Secretary, and
delivered to the Trustee.

         "Completion Date" has the meaning specified in Section 10.4(f).
          ---------------                               ---------------

         "Constituent Person" has the meaning specified in Section 10.11.
          ------------------                               -------------

         "Conversion Agent" means any Person authorized by the Company to
          ----------------
convert Securities in accordance with Article Ten. The Company has initially
                                      -----------
appointed the Trustee as its Conversion Agent.

         "Conversion Price" means the amount equal to U.S. $1,000 divided by the
          ----------------
Conversion Rate.

         "Conversion Rate" has the meaning specified in Section 10.1.
          ---------------                               ------------

         "Conversion Shares" has the meaning specified in Section 10.4(m).
          -----------------                               ---------------

         "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 633 West 5th
Street, 12th Floor, Los Angeles, California 90071, Attn: Corporate Trust
Department (Cell Therapeutics, Inc.)).

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

         "Defaulted Interest" has the meaning specified in Section 2.8.
          ------------------                               -----------

         "Depositary" means, with respect to any Registered 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 Registered Securities
(or any successor securities clearing agency so registered).

         "Designated Senior Debt" means the Company's obligations under any
          ----------------------
particular Senior Debt in which the instrument creating or evidencing the same,
or the assumption or guarantee thereof, or related agreements or documents to
which the Company is a party, expressly provides that such indebtedness 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).

         "Distribution Date" has the meaning specified in Section 10.4(m).
          -----------------                               ---------------

         "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.
          ---

                                      -5-
<PAGE>

         "Event of Default" has the meaning specified in Section 4.1.
          ----------------                               -----------

         "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 Registered 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 or as it may
          ---------
from time to time be supplemented or amended by one or more indentures
supplemental hereto entered into pursuant to the applicable provisions hereof,
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.

         "Initial Purchasers" means CIBC World Markets Corp., Banc of America
          ------------------
Securities LLC and U.S. Bancorp Piper Jaffray Inc.

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

         "Liquidated Damages" has the meaning specified in the Registration
          ------------------
Rights Agreement.

         "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 Thirteen or otherwise.
----------------

         "Non-electing Share" has the meaning specified in Section 10.11.
          ------------------                               -------------

         "Notice of Default" has the meaning specified in Section 4.1.
          -----------------                               -----------

         "Officers' Certificate" means a certificate signed by the Chairman of
          ---------------------
the Board, a Vice Chairman of the Board, the Chief Executive Officer, the
President or a Vice President and by the principal financial officer, the
Treasurer, an Assistant Treasurer, the Secretary or an Assistant Secretary of
the Company, and delivered to the Trustee.

         "Opinion of Counsel" means a written opinion of counsel, who may be
          ------------------
counsel for or employed by the Company and who shall be 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:

                                      -6-
<PAGE>

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

                  (2) Securities for the payment or redemption of which money in
         the necessary amount has been theretofore deposited with the Trustee or
         any Paying Agent (if 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); and

                  (3) Securities that have been paid pursuant to Section 2.7 or
                                                                 -----------
         in exchange for or in lieu of which other Securities have been
         authenticated and delivered pursuant to this Indenture, other than any
         such Securities in respect of which there shall have been presented to
         the Trustee proof satisfactory to it that such Securities are held by a
         bona fide purchaser in whose hands such Securities are valid
         obligations of the Company;

provided, however, that in determining whether the Holders of the requisite
principal amount of Outstanding Securities are present at a meeting of Holders
of Securities for quorum purposes or have given any request, demand,
authorization, direction, notice, consent or waiver hereunder, Securities owned
by the Company or any other obligor upon the Securities or any Affiliate of the
Company or such other obligor shall be disregarded and deemed not to be
Outstanding, except that, in determining whether the Trustee shall be protected
in relying upon any such determination as to the presence of a quorum or upon
any such request, demand, authorization, direction, notice, consent or waiver,
only Securities that a Responsible Officer of the Trustee actually knows to be
so owned shall be so disregarded. Securities so owned that have been pledged in
good faith may be regarded as Outstanding if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Securities and that the pledgee is not the Company or any other obligor upon the
Securities or any Affiliate of the Company or such other obligor.

         "Paying Agent" means any Person authorized by the Company to pay the
          ------------
principal of 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.

         "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 2.2.
          -------------------                               -----------

         "Place of Payment" has the meaning specified in Section 2.2.
          ----------------                               -----------

         "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,

                                      -7-
<PAGE>

for the purposes of this definition, any Security authenticated and delivered
under Section 2.7 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.

         "Purchase Agreement" means the Purchase Agreement, dated as of June 7,
          ------------------
2001, between the Company and the Initial Purchasers, as such agreement may be
amended from time to time.

         "Purchased Shares" has the meaning specified in Section 10.4(f).
          ----------------                               ---------------

         "Purchasers" has the meaning specified in Section 9.9.
          ----------                               -----------

         "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.

         "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.

         "Registered Securities" has the meaning specified in Section 2.1.
          ---------------------                               -----------

         "Registrable Securities" has the meaning specified in the Registration
          ----------------------
Rights Agreement.

         "Registration Default" has the meaning specified in the Registration
          --------------------
Rights Agreement.

         "Registration Rights Agreement" means the Registration Rights
          -----------------------------
Agreement, dated the date hereof, by and among the Company and the Initial
Purchasers.

         "Regular Record Date" for interest payable in respect of any Registered
          -------------------
Security on any Interest Payment Date means the June 1 and the December 1
(whether or not a Business Day), as the case may be, next preceding such
Interest Payment Date.

         "Representative" means (1) the indenture trustee or other trustee,
          --------------
agent or representative for any Designated Senior Debt or (2) with respect to
Designated Senior Debt that does not have any such trustee, agent or other
representative, (A) in the case of such Designated Senior Debt issued pursuant
to an agreement providing for voting arrangements as among the holders or owners
of such Designated Senior Debt, any holder or owner of such Designated Senior
Debt acting with the consent of the required Persons necessary to bind such
holders or owners of such Designated Senior Debt and (B) in the case of all
other such Designated Senior Debt, the holder or owner of such Designated Senior
Debt.

                                      -8-
<PAGE>

         "Repurchase Date" has the meaning specified in Section 12.1.
          ---------------                               ------------

         "Repurchase Price" has the meaning specified in Section 12.1.
          ----------------                               ------------

         "Responsible Officer," when used with respect to the Trustee, means any
          -------------------
officer within the Corporate Trust Office, 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.

         "Restricted Global Security" has the meaning specified in Section 2.1.
          --------------------------                               -----------

         "Restricted Securities Legend" means, collectively, the legends
          ----------------------------
substantially in the forms of the legends required in the form of Security
attached hereto as Exhibit A to be placed upon each Security.
                   ---------

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

         "Rule 144A Information" has the meaning specified in Section 8.9.
          ---------------------                               -----------

         "Securities" has the meaning ascribed to it in the first paragraph
          ----------
under the caption "Recitals of the Company."

         "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 2.6.
                      -----------

         "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 rent payable in
connection with, and all fees, costs, claims, expenses and other amounts payable
in connection with, the following, whether absolute or contingent, secured or
unsecured, due or to become due, outstanding on the date of this Indenture or
thereafter created, incurred or assumed: (1) all the Company's indebtedness
evidenced by a credit or loan agreement, note, bond, debenture, or other similar
instrument whether or not the recourse of the lender is to all of the Company's
assets or only to a portion, (2) all of the Company's indebtedness, obligations
and other liabilities, contingent or otherwise, for borrowed money, including,
without limitation, overdrafts, foreign exchange contracts, currency agreements,
interest rate protection agreements and any loans or advances from banks,
whether or not evidenced by notes or similar instruments, or bonds, debentures,
notes or similar instruments, whether or not the recourse of the lender is to
all of the Company's assets or only to a portion thereof, (3) all of the
Company's obligations as

                                      -9-
<PAGE>

lessee under leases required to be capitalized on the balance sheet of the
lessee under generally accepted accounting principles, (4) all of the Company's
obligations as lessee under leases for facilities, equipment or other assets
entered into for financing purposes, whether or not capitalized, (5) all of the
Company's obligations and other liabilities, contingent or otherwise, under any
lease or related document, including a purchase agreement, in connection with
the lease of real property or improvements, or any personal property included as
part of any such lease, which provides that the Company is contractually
obligated to purchase or cause a third party to purchase the leased property and
thereby guarantee a residual value of leased property to the lessor and all of
the Company's obligations under such lease or related document to purchase or
cause a third party to purchase the leased property, whether or not such lease
transaction is characterized as an operating lease or capitalized lease in
accordance with generally accepted accounting principles, (6) all of the
Company's obligations under interest rate and currency swaps, caps, floors,
collars, hedge agreements, forward contracts, or similar agreements or
arrangements, (7) all of the Company's obligations with respect to letters of
credit, bank guarantees, bankers' acceptances and similar facilities, including
related reimbursement obligations, (8) all of the Company's obligations issued
or assumed as the deferred purchase price of property or services (but excluding
trade accounts payable and accrued liabilities arising in the ordinary course of
business), (9) all of the Company's obligations of the type referred to in
clauses (1) through (8) 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 Company's property and (10) renewals, extensions,
modifications, replacements, restatements and refundings of, or any indebtedness
or obligation issued in exchange for, any such indebtedness or obligation
described in clauses (1) through (9) of this definition; provided, however, that
Senior Debt shall not include the Securities or any indebtedness or obligation
if the terms of such indebtedness or obligation (or the terms of the instrument
under which such indebtedness or obligation is issued) expressly provides that
such indebtedness or obligation is not superior in right of payment to the
Securities; and provided, further, that Senior Debt shall not include accounts
payable or other accrued liabilities or obligations incurred in the ordinary
course of business in connection with the obtaining of materials or services and
any indebtedness or obligation that the Company may owe to any direct or
indirect Subsidiary.

         "Shelf Registration Statement" has the meaning specified in the
          ----------------------------
Registration Rights Agreement.

         "Significant Subsidiary" means any Subsidiary that would be a
          ----------------------
"significant subsidiary" as defined in Article 1, Rule 1-02 of Regulation S-X,
promulgated pursuant to the Securities Act, as such regulation is in effect on
the date hereof.

         "Special Record Date" for the payment of any Defaulted Interest means a
          -------------------
date fixed by the Company pursuant to Section 2.8.

         "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.

                                     -10-
<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 that 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 2.7 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 Days" means (1) if the Common Stock is listed or admitted for
          ------------
trading on any national securities exchange, days on which such national
securities exchange is open for business; (2) 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; or (3) if the Common Stock is not listed or admitted for trading on
any national 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 as in force
          -------------------
at the date as of which this instrument was executed; provided, however, that in
the event the Trust Indenture Act of 1939 is amended after such date, "Trust
Indenture Act" means, to the extent required by any such amendment, the Trust
Indenture Act of 1939 as so amended.

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

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

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

         SECTION 1.2      Compliance Certificates and Opinions.
                          ------------------------------------

                                     -11-
<PAGE>

         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
                                                                       -------
8.8) shall include:
---

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

         (b) 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;

         (c) a statement that, in the opinion of 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

         (d) a statement as to whether, in the opinion of each such individual,
such condition or covenant has been complied with; provided, however, with
respect to matters of fact, an Opinion of Counsel may rely on an Officers'
Certificate or certificates of public officials.

         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 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, or in
the exercise of reasonable care should know, that the certificate or opinion or
representations with respect to such matters are erroneous.

                                     -12-
<PAGE>

         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 of Securities.
                           -----------------------------

         (a) Any request, demand, authorization, direction, notice, consent,
waiver or other action provided or permitted by this Indenture to be given or
taken by Holders of Securities may be embodied in and evidenced by 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. Such action
shall become effective when such instrument or instruments 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 delivered
to the Trustee. Such instrument or instruments (and the action embodied therein
and evidenced thereby) are herein sometimes referred to as the "Act" of the
                                                                ---
Holders of Securities signing such instrument or instruments. 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 5.1) conclusive in favor of the Trustee
                               -----------
and the Company if made in the manner provided in this Section 1.4.
                                                       -----------

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

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

         (d) 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 that 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.
     -----------

         (e) 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
thirtieth day (or, if later, the date of the most recent list of Holders
required to be provided pursuant to Section 13.1) 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,

                                     -13-
<PAGE>

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 (1) any notice of
default or breach referred to in Section 4.1(d), if such default or breach has
                                 --------------
occurred and is continuing and the Trustee shall not have given such a notice to
the Company, (2) any declaration of acceleration referred to in Section 4.2, if
                                                                -----------
an Event of Default has occurred and is continuing and the Trustee shall not
have given such a declaration to the Company, or (3) any direction referred to
in Section 4.12, if the Trustee shall not have taken the action specified in
   ------------
such direction, then, with respect to clauses (2) and (3), 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 next succeeding Business Day) following the day on which
the Trustee receives such declaration or direction, and, with respect to clause
(1), 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 (2) or (3), and promptly after setting any record date with respect to
clause (1), 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, however, 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 ninetieth day after such record date, such notice, declaration or
direction shall automatically and without any action by any Person be cancelled
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 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.

         (f) Except as provided in Sections 4.2 and 4.13, 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.

         SECTION 1.5       Notices, Etc., to Trustee and Company.
                           -------------------------------------

                                     -14-
<PAGE>

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

         (a) the Trustee by any Holder of Securities or by the Company shall be
sufficient for every purpose hereunder if made, given, furnished or filed in
writing to or with the Trustee and received at the Corporate Trust Office,
Attention: Corporate Trust Department, and shall be deemed given when received,

         (b) the Company by the Trustee or by any Holder of Securities 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 201 Elliott Avenue West, Suite
400, Seattle, Washington 98119, Attention: Louis A. Bianco (telecopy no.: (206)
284-6206), or at any other address previously furnished in writing to the
Trustee by the Company, and shall be deemed given when received.

         Any request, demand, authorization, direction, notice, consent,
election or waiver required or permitted under this Indenture shall be in the
English language, except that any published notice may be in an official
language of the country of publication.

         SECTION 1.6       Notice to Holders of Securities; Waiver.
                           ---------------------------------------

         Except as otherwise expressly provided herein, where this Indenture
provides for notice to Holders of Securities of any event, such notice shall be
sufficiently given to Holders if in writing and mailed, first-class postage
prepaid, to each Holder of a Security 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 of a Registered Security shall affect the
sufficiency of such notice with respect to other Holders of Registered
Securities. 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 of Registered Securities as shall be made 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
mailed.

         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 of Securities 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.
                          ----------------------------------------

                                     -15-
<PAGE>

         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 and by
the Trustee 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 of
Securities, any benefit or legal or equitable right, remedy or claim under this
Indenture. The provisions of Article Eleven 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,
INCLUDING, WITHOUT LIMITATION, THE NEW YORK GENERAL OBLIGATIONS LAW ss.5-1401.

         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 of a Security has a right to convert his Security shall not be a Business
Day at a Place of Payment or Place of Conversion, as the case may be, 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
Repurchase Price (whether the same is payable in cash or in shares of Common
Stock) with respect to, or delivery for conversion of, such Security need not be
made at such Place of Payment or Place of Conversion, as the case may be, 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, 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;
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,

                                     -16-
<PAGE>

Redemption Date, Repurchase Date, Stated Maturity or last day for conversion, 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 such act to be a part of and
govern this Indenture, the latter provision shall control. If any provision of
this Indenture modifies or excludes any provision of the Trust Indenture Act
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.

         SECTION 1.14     Counterparts.
                          ------------

         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.

                                  ARTICLE TWO

                                THE SECURITIES

         SECTION 2.1      Form Generally.
                          --------------

         The Securities and the Trustee's Certificate of Authentication shall be
in substantially the form set forth in Exhibit A hereto, which Exhibit is a part
                                       ---------
of this Indenture, with such appropriate insertions, omissions, substitutions
and other variations as are required or permitted by this Indenture, and may
have such letters, numbers or other marks of identification and such legends or
endorsements placed thereon as may be required to comply with the rules of any
securities exchange or the Internal Revenue Code of l986, as amended, and
regulations thereunder (the "Code"), or as may, consistently 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, and shall sometimes be referred to as the "Registered
                                                           ----------
Securities."
----------

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

                                     -17-
<PAGE>

         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). Such Global Security, together with its Successor
Securities that are Global Securities, are collectively herein called the
"Restricted Global Security."
 --------------------------

         SECTION 2.2      Title and Terms.
                          ---------------

         The aggregate principal amount of Securities that may be authenticated
and delivered under this Indenture is limited to U.S.$150,000,000 (or such
greater amount necessary to reflect exercise of the Initial Purchasers'
over-allotment option in compliance with the Purchase Agreement, but not in
excess of U.S.$180,000,000), except for Securities authenticated and delivered
in exchange for, or in lieu of, other Securities pursuant to Section 2.5, 2.6,
                                                             -----------  ---
2.7, 7.5, 9.8, 10.2 or 12.3(e).
---  ---  ---  ----    -------

         The Securities shall be known and designated as the "5.75% Convertible
Subordinated Notes due 2008" of the Company. Their Stated Maturity shall be June
15, 2008 and they shall bear interest on their principal amount from June 13,
2001, payable semiannually in arrears on June 15 and December 15 in each year,
commencing December 15, 2001, at the rate of 5.75% per annum until the principal
thereof is due and at the rate then in effect 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 attached hereto as Exhibit A,
                                                                    ---------
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 12.3 (any city in which any Paying Agent is located being
            ------------
herein called a "Place of Payment").
                 ----------------

         The Registrable Securities are entitled to the benefits of a
Registration Rights Agreement as provided by the form of Securities attached
hereto as Exhibit A. The Securities are entitled to the payment of Liquidated
          ---------
Damages as provided in the Registration Rights Agreement.

         The Securities shall be redeemable at the option of the Company, as
provided in Article Nine and in the form of Securities attached hereto as
Exhibit A.
---------

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

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

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

                                     -18-
<PAGE>

         SECTION 2.3      Denominations.
                          -------------

         The Securities shall be issuable only in registered form, without
coupons, in denominations of U.S.$1,000 and integral multiples thereof.

         SECTION 2.4      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, one of its Vice Presidents, its Chief Financial Officer,
its Treasurer or its Controller and attested by its 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 provided in this Indenture 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 2.5      Global Securities; Temporary Securities.
                          ---------------------------------------

         (a)      Global Securities

                  (1) 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.

                  (2) Notwithstanding any other provision in this Indenture, no
         Global Security may be exchanged in whole or in part for Securities
         registered, and no transfer of a Global Security in whole or in part
         may be registered, in the name of any Person other than the Depositary
         for such Global Security or a nominee thereof unless (A) such
         Depositary (i) has notified the Company that it is unwilling or unable
         to continue as

                                     -19-
<PAGE>

         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.

               (3)  If any Global Security is to be exchanged for other
         Securities or cancelled 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
                                                                      -------
         Two. If any Global Security is to be exchanged for other Securities or
         ---
         cancelled 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 2.6, then either (A) such Global Security
                              -----------
         shall be so surrendered for exchange or cancellation, as provided in
         this Article Two, or (B) the principal amount thereof shall be reduced
              -----------
         or increased by an amount equal to the portion thereof to be so
         exchanged or cancelled 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 Section 2.6(c) and as
                                                        --------------
         otherwise provided in this Article Two, authenticate and make available
                                    -----------
         for delivery 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 Two.
                                                                -----------

               (4)  Every Security authenticated and delivered upon registration
         of transfer of, or in exchange for or in lieu of, a Global Security or
         any portion thereof, whether pursuant to this Article Two 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 Security or
         a nominee thereof, in which case such Registered Security shall be
         authenticated and delivered in definitive, fully registered form,
         without interest coupons.

               (5)  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 Registered 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 shall 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 shall not be
         considered the owners or holders thereof.

                                     -20-
<PAGE>

         (b)   Temporary Securities

         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 Registered Securities in lieu of
which they are issued and with such appropriate insertions, omissions,
substitutions and other variations as the officers executing such Registered
Securities may determine, as evidenced by their execution of such Securities.

         If temporary Securities are issued, the Company shall 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 8.2, 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 2.6      Registration, Registration of Transfer and Exchange;
                          ----------------------------------------------------
                          Restrictions on Transfer.
                          ------------------------

         (a)   The Company shall cause to be kept at the Corporate Trust Office
a register (the register maintained in such office and in any other office or
agency of the Company designated pursuant to Section 8.2 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 Registered Securities and of transfers of Registered Securities.
The Trustee is hereby appointed "Security Registrar" for the purpose of
                                 -------- ---------
registering Registered Securities and transfers and exchanges of Registered
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 8.2 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.

         At the option of the Holder, and subject to the other provisions of
this Section 2.6, 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 2.6, the Company shall execute, and the Trustee shall
        -----------
authenticate and make available for delivery, the Securities 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

                                     -21-
<PAGE>

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.

         All Securities issued upon any registration of transfer or exchange of
Securities shall be the valid obligations of the Company, evidencing the same
debt, subject to the other provisions of this Section 2.6, 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 for any registration of transfer or
exchange of Securities except as provided in Section 2.7, 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 2.5, 7.5, 9.8,
                                                         -----------  ---  ---
10.2 or 12.3(e) (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, that 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.

         In the event of a redemption of the Securities, the Company shall not
be required (1) 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 (2) to register the
transfer of or exchange any Security, or portion thereof, called for redemption.

         (b)   Restricted Securities Legends. All Securities shall bear the
applicable Restricted Securities Legend subject to the following:

               (1)  subject to the following clauses of this Section 2.6(b), a
                                                             --------------
         Security or any portion thereof that is exchanged, upon transfer or
         otherwise, for a Global Security or any portion thereof shall bear the
         Restricted Securities Legend borne by such Global Security while
         represented thereby;

               (2)  subject to the following clauses of this Section 2.6(b), a
                                                             --------------
         new Security that is not a Global Security and is issued in exchange
         for another Security (including a Global Security) or any portion
         thereof, upon transfer or otherwise, shall bear the Restricted
         Securities Legend borne by such other Security;

               (3)  any Securities that are sold or otherwise disposed of
         pursuant to an effective registration statement under the Securities
         Act (including the Shelf Registration Statement), together with their
         Successor Securities, shall not bear a Restricted Securities Legend;
         the Company shall inform the Trustee in writing of the effective date
         of any such registration statement registering the Securities under the
         Securities Act and shall notify the Trustee at any time when
         prospectuses may not be delivered with respect to Securities to be sold
         pursuant to such registration statement. The Trustee shall not be
         liable for any action taken or omitted to be taken by it in good faith
         in accordance with the aforementioned registration statement;

                                     -22-
<PAGE>

               (4)  at any time after the Securities may be freely transferred
         without registration under the Securities Act or without being subject
         to transfer restrictions pursuant to the Securities Act, a new Security
         that does not bear a Restricted Securities Legend may be issued in
         exchange for or in lieu of a Security (other than a Global Security) or
         any portion thereof that bears such a legend if the Trustee has
         received a certificate regarding the unrestricted nature of the
         Securities, satisfactory to the Trustee and duly executed by the Holder
         of such legended Security or his attorney duly authorized in writing,
         and after such date and receipt of such certificate, the Trustee shall
         authenticate and make available for delivery such a new Security in
         exchange for or in lieu of such other Security as provided in this
         Article Two;
         -----------

               (5)  a new Security that does not bear a Restricted Securities
         Legend may be issued in exchange for or in lieu of a Security (other
         than a Global Security) or any portion thereof that bears such a legend
         if, in the Company's judgment, placing such a legend upon such new
         Security is not necessary to ensure compliance with the registration
         requirements of the Securities Act, and the Trustee, at the direction
         of the Company, shall authenticate and make available for delivery such
         a new Security as provided in this Article Two; and
                                            -----------

               (6)  notwithstanding the foregoing provisions of this Section
                                                                     -------
         2.6(b), a Successor Security of a Security that does not bear a
         ------
         particular form of Restricted Securities Legend shall not bear such
         form of legend unless the Company has reasonable cause to believe that
         such Successor Security is a "restricted security" within the meaning
         of Rule 144, in which case the Trustee, at the direction of the
         Company, shall authenticate and make available for delivery a new
         Security bearing a Restricted Securities Legend in exchange for such
         Successor Security as provided in this Article Two.
                                                -----------

         (c)   Neither the Trustee, the Paying Agent nor any of their agents
shall (1) have any duty to monitor compliance with or with respect to any
federal or state or other securities or tax laws or (2) have any duty to obtain
documentation on any transfers or exchanges other than as specifically required
hereunder.

         SECTION 2.7     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 make available for delivery
in exchange therefor a new Security of like tenor and principal amount and
bearing a number not contemporaneously outstanding.

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

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

         (b)   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,

                                     -23-
<PAGE>

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 make available for delivery, 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, 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 2.7, 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, that 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 2.7 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 2.7 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 2.8     Payment of Interest; Interest Rights Preserved.
                         ----------------------------------------------

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

         (a)   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

                                     -24-
<PAGE>

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 provided
in this clause. 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 15 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 (b).

         (b)   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 2.8 and Section
                                                     -----------     -------
2.6, 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, that were carried by such other
Security.

         Interest on any Security that is converted in accordance with Section
                                                                       -------
10.2 during a Record Date Period shall be payable in accordance with the
----
provisions of Section 10.2.
              ------------

         SECTION 2.9     Persons Deemed Owners.
                         ---------------------

         Prior to due presentment of a Security for registration of transfer,
the Company, the Trustee and any agent of the Company or the Trustee may treat
the Person in whose name such Security is registered as the owner of such
Security for the purpose of receiving payment of principal of, premium, if any,
and (subject to Section 2.8) interest on such Security and for all other
                -----------
purposes whatsoever, whether or not such Security be overdue, and neither the
Company, the Trustee nor any agent of the Company or the Trustee shall be
affected by notice to the contrary.

         SECTION 2.10    Cancellation.
                         ------------

         All Securities surrendered for payment, redemption, repurchase,
registration of transfer or exchange or conversion shall, if surrendered to any
Person other than the Trustee, be delivered to

                                     -25-
<PAGE>

the Trustee. All Securities so delivered to the Trustee shall be cancelled
promptly by the Trustee. No Securities shall be authenticated in lieu of or in
exchange for any Securities cancelled as provided in this Section 2.10. The
                                                          ------------
Trustee shall dispose of all cancelled Securities in accordance with applicable
law and its customary practices in effect from time to time.

         SECTION 2.11    Computation of Interest.
                         -----------------------

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

         SECTION 2.12    CUSIP Numbers.
                         -------------

         The Company in issuing Securities may use "CUSIP" numbers (if then
generally in use) in addition to serial numbers; the Trustee shall use such
CUSIP numbers in addition to serial numbers in notices of redemption and
repurchase as a convenience to Holders; provided, however, 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 shall promptly notify the Trustee in writing of any change
in any such CUSIP number.

                                 ARTICLE THREE

                          SATISFACTION AND DISCHARGE

         SECTION 3.1     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 registration of transfer or
exchange, or replacement of Securities herein expressly provided for and any
right to receive Liquidated Damages as provided in the form of Securities
attached hereto as Exhibit A and the Company's obligations to the Trustee
                   ---------
pursuant to Section 5.7), 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

         (a)   either

               (1)  all Securities theretofore authenticated and delivered
         (other than (A) Securities that have been destroyed, lost or stolen and
         that have been replaced or paid as provided in Section 2.7 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 8.3) have been delivered to the Trustee for cancellation; or
         -----------

                                     -26-
<PAGE>

               (2)    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 (a)(1) above)

               (i)    have become due and payable, or

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

               (iii)  are to be called for redemption within one year under
         arrangements satisfactory to the Trustee for the giving of notice of
         redemption by the Trustee in the name, and at the expense, of the
         Company, and the Company, in the case of clause (i), (ii) or (iii)
         above, has deposited or caused to be deposited with the Trustee as
         trust funds (immediately available to the Holders in the case of clause
         (i) above) an amount sufficient to pay and discharge the entire
         principal, premium, if any, interest and Liquidated Damages, if any, on
         such Securities not theretofore delivered to the Trustee for
         cancellation, to the date of such deposit (in the case of Securities
         that have become due and payable) or to the Stated Maturity or
         Redemption Date, as the case may be;

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

         (c)   the Company has delivered to the Trustee an Officers' Certificate
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 5.7, the obligations of
                                                -----------
the Company to any Authenticating Agent under Section 5.12, the obligation of
                                              ------------
the Company to pay Liquidated Damages, if money shall have been deposited with
the Trustee pursuant to clause (a)(2) of this Section 3.1, the obligations of
                                              -----------
the Trustee under Section 3.2 and the last paragraph of Section 8.3, and the
                  -----------                           -----------
obligations of the Company and the Trustee under Section 2.6 and Article Ten
                                                 -----------     -----------
shall survive. Funds held in trust pursuant to this Section 3.1 are not subject
                                                    -----------
to the provisions of Article Eleven.
                     --------------

         In the event that the Company is required to pay Liquidated Damages to
the Holders pursuant to the Registration Rights Agreement, the Company will
provide written notice ("Liquidated Damages Notice") to the Trustee of its
obligation to pay Liquidated Damages no later than 15 days prior to the proposed
payment date for the Liquidated Damages, and the Liquidated Damages Notice shall
set forth the amount of Liquidated Damages to be paid by the Company on such
payment date. The Trustee shall not at any time be under any duty or
responsibility to any Holder to determine the Liquidated Damages or with respect
to the nature, extent or calculation of the amount of Liquidated Damages when
made, or with respect to the method employed in such calculation of the
Liquidated Damages. Unless the Trustee receives a

                                     -27-

<PAGE>

Liquidated Damages Notice within the time period specified above, the Trustee is
entitled to assume that no Liquidated Damages are due and payable.

         SECTION 3.2     Application of Trust Money.
                         --------------------------

         Subject to the provisions of the last paragraph of Section 8.3, all
                                                            -----------
money deposited with the Trustee pursuant to Section 3.1 shall be held in trust
                                             -----------
and applied by it, in accordance with the provisions of the Securities and this
Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent), to the Persons entitled
thereto, of the principal, premium, if any, Liquidated Damages, if any, and
interest for whose payment such money has been deposited with the Trustee.

         All moneys deposited with the Trustee pursuant to Section 3.1 (and held
                                                           -----------
by it or any Paying Agent) for the payment of Securities subsequently converted
shall be returned to the Company upon Company Request.

                                  ARTICLE FOUR

                                    REMEDIES

         SECTION 4.1      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 Eleven 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):

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

         (b)   default in the payment of any interest if any, upon any Security
when it becomes due and payable, and continuance of such default for a period of
30 days, whether or not such payment is prohibited by the subordination
provisions of this Indenture; or

         (c)   failure by the Company to give the Company Notice in accordance
with Section 12.3, whether or not such notice is prohibited by the subordination
     ------------
provisions of this Indenture; or

         (d)   default in the performance, or breach, of any covenant of the
Company in this Indenture (other than a covenant a default in the performance or
breach of which is specifically dealt with elsewhere in this Section 4.1), 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 aggregate
principal

                                     -28-

<PAGE>

amount of the Outstanding Securities, a written notice specifying such default
or breach and requiring it to be remedied and stating that such notice is a
"Notice of Default" hereunder; or
 -----------------

         (e)   default in the payment when due of the principal of any
indebtedness under any bond, debenture, note or other evidence of indebtedness
for money borrowed by the Company or any Significant Subsidiary with a principal
amount then outstanding in excess of U.S. $10,000,000, whether such indebtedness
now exists or shall hereafter be created, if the indebtedness is not discharged
and such default continues for a period of 30 days or more, or if such
indebtedness has been accelerated, 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 such acceleration to
be rescinded or annulled and stating that such notice is a "Notice of Default"
hereunder; or

         (f)   the entry by a court having jurisdiction in the premises of (1) 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 (2) 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 its property, or ordering the winding up or liquidation of
its affairs, and the continuance of any such decree or order for relief or any
such other decree or order unstayed and in effect for a period of 60 consecutive
days; or

         (g)   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 it 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
it, or the filing by it of a petition or answer or consent seeking
reorganization or similar relief under any applicable federal or state law, or
the consent by it to the filing of such petition or to the appointment of or
taking possession by a custodian, receiver, liquidator, assignee, trustee,
sequestrator or other similar official of the Company or any Significant
Subsidiary or of any substantial part of its property, or the making by it of an
assignment for the benefit of creditors, or the admission by it in writing of
its inability to pay its debts generally as they become due, or the taking of
corporate action by the Company or any Significant Subsidiary in furtherance of
any such action.

         SECTION 4.2     Acceleration of Maturity; Rescission and Annulment.
                         --------------------------------------------------

         If an Event of Default (other than an Event of Default specified in
Section 4.1(f) or 4.1(g)) occurs and is continuing, then in every such case the
--------------    -------
Trustee or the Holders of not less

                                     -29-

<PAGE>

than 25% in principal amount of the Outstanding Securities may 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 and all accrued interest thereon shall
become immediately due and payable. If an Event of Default specified in Section
                                                                        -------
4.1(f) or 4.1(g) occurs, the principal of, and accrued interest on, all the
------    ------
Securities shall ipso facto become immediately due and payable without any
declaration or other Act of the Holder 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 Four provided, the Holders of a
                                   ------------
majority in principal amount of the Outstanding Securities, by written notice to
the Company and the Trustee, may rescind and annul such declaration and its
consequences if:

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

                  (1) all overdue interest and Liquidated Damages, if any, on
         all Securities,

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

                  (3) to the extent permitted by applicable law, interest upon
         overdue interest at the rate then in effect, and

                  (4) 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; and

         (b)      all Events of Default, other than the non-payment of the
principal of, and any premium and interest on, Securities that have become due
solely by such declaration of acceleration, have been cured or waived as
provided in Section 4.13.
            ------------

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

         SECTION 4.3      Collection of Indebtedness and Suits for Enforcement
                          ----------------------------------------------------
                          by Trustee.
                          ----------

         The Company covenants that if:

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

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

                                     -30-
<PAGE>

the Company will upon demand of the Trustee pay to it, for the benefit of the
Holders of such Securities, the whole amount then due and payable on such
Securities for principal, premium, if any, Liquidated Damages, if any, and
interest on any overdue principal, premium, if any, Liquidated Damages, if any,
and, to the extent permitted by applicable law, on any overdue interest at the
rate then in effect, 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 of Securities by such appropriate judicial proceedings as the Trustee
shall deem most effective 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 4.4      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 relating 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 (whether or not the principal of, and any
interest on, the Securities shall then be due and payable as therein expressed
or by declaration or otherwise and whether or not 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,

         (a) to file and prove a claim for the whole amount of principal,
premium, if any, Liquidated Damages, 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 of Securities allowed in such judicial proceeding, and

         (b) 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 of
Securities to make such payments to the Trustee and, in the event that the
Trustee shall

                                     -31-
<PAGE>

consent to the making of such payments directly to the Holders of Securities, 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 5.7.
                                            -----------

         Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder of a Security
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 of a Security 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 4.5      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 4.6      Application of Money Collected.
                          ------------------------------
         Subject to Article Eleven, any money collected by the Trustee pursuant
                    --------------
to this Article Four 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 5.7;
                                                                    -----------

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

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

         SECTION 4.7      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:

                                     -32-
<PAGE>

         (a) such Holder has previously given written notice to the Trustee of a
continuing Event of Default;

         (b) 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;

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

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

         (e) the Trustee has not received any direction inconsistent with such
written request from the Holders of a majority of the aggregate principal amount
of the Outstanding Securities during the 60 day period referred to in (d) above;
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.

         SECTION 4.8      Unconditional Right of Holders to Receive Principal,
                          ---------------------------------------------------
                          Premium and Interest and to Convert.
                          -----------------------------------

         Notwithstanding any other provision in this Indenture, the Holder of
any Security shall have the right, which is absolute and unconditional, to
receive payment of the principal of, premium, if any, and (subject to Section
                                                                      -------
2.8) 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 Ten, and to institute suit for the enforcement of any
                -----------
such payment and right to convert, and such rights shall not be impaired without
the consent of such Holder.

         SECTION 4.9      Restoration of Rights and Remedies.
                          ----------------------------------

         If the Trustee or any Holder of a Security 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 of Securities 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 4.10     Rights and Remedies Cumulative.
                          ------------------------------

                                     -33-
<PAGE>

         Except as otherwise provided with respect to the replacement or payment
of mutilated, destroyed, lost or stolen Securities in the last paragraph of
Section 2.7, no right or remedy herein conferred upon or reserved to the Trustee
-----------
or to the Holders of Securities 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 4.11     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 Four or by
                                                           ------------
law to the Trustee or to the Holders of Securities 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 of Securities, as the
case may be.

         SECTION 4.12     Control by Holders of Securities.
                          --------------------------------

         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

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

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

         SECTION 4.13     Waiver of Past Defaults.
                          -----------------------

         The Holders, either (a) through the written consent of not less than a
majority in principal amount of the Outstanding Securities 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 a majority 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 (1) in the payment of the principal of, premium,
if any, interest, the Repurchase Price or Liquidated Damages, if any, on any
Security or (2) in respect of a covenant or provision hereof that under Article
                                                                        -------
Seven 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.

                                     -34-
<PAGE>

         SECTION 4.14     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 4.14 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, Liquidated Damages, 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 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 Ten.
                                        -----------

         SECTION 4.15     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, that 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 FIVE

                                  THE TRUSTEE

         SECTION 5.1      Certain Duties and Responsibilities.
                          -----------------------------------

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

                  (1) 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 read into this Indenture
         against the Trustee; and

                  (2) 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
         that by any provision

                                     -35-
<PAGE>

         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.

         (b)      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.

         (c)      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

                  (1) this paragraph (c) shall not be construed to limit the
         effect of paragraph (a) of this Section 5.1;
                                         -----------

                  (2) 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;

                  (3) 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

                  (4) 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.

         (d)      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 5.1.
-----------

         SECTION 5.2      Notice of Defaults.
                          ------------------

         Within 90 days after the occurrence of any default hereunder as to
which a Responsible Officer of the Trustee has actually received written notice,
the Trustee shall give to all Holders of Securities, 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 determine that the withholding
of such notice is in the interest of the Holders. For the purpose of

                                     -36-
<PAGE>

this Section 5.2, the term "default" means any event that is, or after notice or
     -----------
lapse of time or both would become, an Event of Default.

         SECTION 5.3      Certain Rights of Trustee.
                          -------------------------

         Subject to the provisions of Section 5.1:
                                      -----------

         (a) the Trustee may 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 believed by it to be genuine and to have been signed or
presented by the proper party or parties;

         (b) 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;

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

         (d) 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;

         (e) 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 of Securities pursuant to this Indenture, unless such Holders
shall have offered to the Trustee reasonable security or indemnity against the
costs, expenses and liabilities that might be incurred by it in compliance with
such request or direction;

         (f) the Trustee shall not be bound to make any investigation into the
facts or matters stated in any resolution, certificate, statement, instrument,
opinion, report, notice, request, 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

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

                                     -37-
<PAGE>

         SECTION 5.4      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. The Trustee shall not be accountable for the use or
application by the Company of Securities or the proceeds thereof.

         SECTION 5.5      May Hold Securities, Act as Trustee under Other
                          -----------------------------------------------
                          Indentures.
                          ----------

         The Trustee, any Authenticating Agent, any Paying Agent, any Conversion
Agent 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 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 5.6      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 5.7      Compensation and Reimbursement.
                          ------------------------------

         The Company agrees

         (a) 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);

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

         (c) to indemnify the Trustee (and its directors, officers, employees
and agents) for, and to hold it harmless against, any and all loss, damage,
claim, liability or expense, including taxes (other than taxes based on the
income of the Trustee), incurred without negligence, bad faith or willful
misconduct on its part, arising out of or in connection with the acceptance or

                                     -38-
<PAGE>

administration of this trust, including the reasonable costs, expenses and
reasonable attorneys' fees of defending itself against any claim or liability in
connection with the exercise or performance of any of its powers or duties
hereunder.

         When the Trustee incurs expenses or renders services in connection with
an Event of Default specified in Section 4.1(f) or Section 4.1(g) with respect
                                 --------------    --------------
to the Company, 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 Trustee shall have a lien prior to the Securities as to all
property and funds held by it hereunder for any amount owing it or any
predecessor Trustee pursuant to this Section 5.7, except with respect to funds
                                     -----------
held in trust for the benefit of the Holders of particular Securities.

         The provisions of this Section 5.7 shall survive the termination of
                                -----------
this Indenture or the earlier resignation or removal of the Trustee.

         SECTION 5.8      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 a
combined capital and surplus (or for such purposes, the combined capital and
surplus of any parent holding company) of at least U.S. $25,000,000, subject to
supervision or examination by federal or state authority, in good standing and
having an established place of business or agency 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 5.8, 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 5.8, 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 5.9.
                               -----------

         SECTION 5.9      Resignation and Removal; Appointment of Successor.
                          -------------------------------------------------

         (a) No resignation or removal of the Trustee and no appointment of a
successor Trustee pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee in accordance with the
applicable requirements of Section 5.10.
                           ------------

         (b) 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 5.10 shall not have been delivered to the Trustee within 30 days
   ------------
after the giving of such notice of resignation, the resigning Trustee or the
Company may petition any court of competent jurisdiction for the appointment of
a successor Trustee.

         (c) The Trustee may be removed at any time by Act of the Holders of a
majority in principal amount of the Outstanding Securities, delivered to the
Trustee and the Company. If the

                                     -39-
<PAGE>

instrument of acceptance by a successor Trustee required by Section 5.10 shall
                                                            ------------
not have been delivered to the Trustee within 30 days after the giving of such
notice of removal, the removed Trustee or the Company may petition any court of
competent jurisdiction for the appointment of a successor Trustee.

         (d)      If at any time:

                  (1) the Trustee shall cease to be eligible under Section 5.8
                                                                   -----------
         and shall fail to resign after written request therefor by the Company
         or by any Holder of a Security who has been a bona fide Holder of a
         Security for at least six months, or

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

then, (i) in any such case the Company may remove the Trustee, or (ii) in the
case of clause (d)(1) above only and subject to Section 4.14, any Holder of a
                                                ------------
Security who has been a bona fide Holder of a Security for at least six months
may, on behalf of himself and all others similarly situated, petition any court
of competent jurisdiction for the removal of the Trustee and the appointment of
a successor Trustee.

         (e)      If the Trustee shall resign, be removed or become incapable of
acting, or if a vacancy shall occur in the office of Trustee for any cause, the
Company shall promptly appoint a successor Trustee and shall comply with the
applicable requirements of this Section 5.9 and Section 5.10. If, within one
                                -----------     ------------
year after such resignation, removal or incapability, or 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 5.10, 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 of Securities
and accepted appointment in the manner required by this Section 5.9 and Section
                                                        -----------     -------
5.10, any Holder of a Security who has been a bona fide Holder of a Security for
----
at least six months may, on behalf of himself and all others similarly situated,
petition any court of competent jurisdiction for the appointment of a successor
Trustee.

         (f)      The successor Trustee shall give notice of each resignation
and each removal of the Trustee and each appointment of a successor Trustee to
all Holders of Securities 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 5.10    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

                                     -40-
<PAGE>

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. Such retiring Trustee shall, upon payment of its
charges, promptly 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 5.11    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, 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 5.12    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 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 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 5.12, such Authenticating Agent
                                       ------------
shall resign immediately in the manner and with the effect specified in this
Section 5.12.
------------

                                     -41-
<PAGE>

         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 5.12), 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 5.12, 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 5.12.
                   ------------

         The Company agrees to pay to each Authenticating Agent from time to
time reasonable compensation for its services under this Section 5.12.
                                                         ------------

         If an Authenticating Agent is appointed with respect to the Securities
pursuant to this Section 5.12, 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.


         By:  State Street Bank and Trust Company of California, N.A.,
         as Authenticating Agent



         By _____________________________
                  Authorized Signature

         SECTION 5.13    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 as Trustee hereunder, to the extent and in the manner
provided by, and subject to the provisions of, the Trust Indenture Act and this
Indenture.

                                     -42-
<PAGE>

         SECTION 5.14    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 SIX

             CONSOLIDATION, MERGER, CONVEYANCE, TRANSFER OR LEASE

         SECTION 6.1     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 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 it or convey, transfer, sell or lease such
Person's properties and assets substantially as an entirety to it, unless:

         (a)      the Person formed by such consolidation or into or with which
the Company is merged, or the Person to which the Company's properties and
assets are conveyed, transferred, sold or leased, shall be (1) 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 or (2) organized under the laws of a jurisdiction outside
the United States of America and have common stock or American Depositary Shares
representing such common stock traded on a national securities exchange in the
United States, including The Nasdaq Stock Market, Inc., and, in each case, 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,
Liquidated Damages, if any, and interest on all of the Securities as applicable,
and the performance or observance of every covenant of this Indenture on the
part of the Company to be performed or observed;

         (b)      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

         (c)      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 7.3.
                         -----------

         SECTION 6.2     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 6.1, the successor Person formed by such consolidation
-----------

                                     -43-
<PAGE>

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 SEVEN

                            SUPPLEMENTAL INDENTURES

         SECTION 7.1     Supplemental Indentures without Consent of Holders of
                         -----------------------------------------------------
                         Securities.
                         ----------

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

         (a)      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 this Indenture; or

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

         (c)      to secure the Securities; or

         (d)      to make provision with respect to the conversion rights of
Holders of Securities pursuant to Section 10.11; or
                                  -------------
         (e)      to make any changes or modifications to this Indenture
necessary in connection with the registration of any Registrable Securities
under the Securities Act as contemplated by the Registration Rights Agreement
(provided such action pursuant to this clause (e) shall not, in the judgment of
the Company, adversely affect the interests of the Holders of Securities in any
material respect); or

         (f)      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

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

         (h)      to cure any ambiguity, to correct or supplement any provision
herein that may be inconsistent with any other provision herein or that 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 (h)

                                     -44-
<PAGE>

shall not, in the judgment of the Company, adversely affect the interests of the
Holders of Securities 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 7.3 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 that may be therein contained.

         SECTION 7.2     Supplemental Indentures with Consent of Holders of
                         --------------------------------------------------
                         Securities.
                         ----------

         With either (a) 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 (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 a majority 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 of Securities under this
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, any premium or the rate of interest payable thereon, or change
         the place at which or the coin or currency in which any Security or the
         interest or any premium thereon or any other amount in respect thereof
         is payable; or

                  (2)    reduce the amount payable on any Security upon
         redemption at the Company's option; or

                  (3)    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

                  (4)    except as permitted by Section 10.11, adversely affect
                                                -------------
         the right to convert any Security as provided in Article Ten; or
                                                          -----------

                  (5)    modify the provisions of this Indenture with respect to
         the subordination of the Securities in a manner adverse to the Holders
         of any Securities; or

                  (6)    reduce the percentage in principal amount of the
         Outstanding Securities the consent of whose Holders is required for any
         supplemental indenture to modify or amend any provision of this
         Indenture or the consent of whose Holders is required for

                                     -45-
<PAGE>

         any waiver (of compliance with certain provisions of this Indenture or
         certain defaults hereunder and their consequences) provided for in this
         Indenture; or

                  (7)    modify any of the provisions of this Section 7.2 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

                  (8)    amend or modify the provisions of Article Twelve in a
                                                           --------------
         manner adverse to the Holders after the Holder's right to require the
         Company to repurchase the Securities upon a Change in Control arises.

         It shall not be necessary for any Act of Holders of Securities under
this Section 7.2 to approve the particular form of any proposed supplemental
     -----------
indenture, but it shall be sufficient if such Act shall approve the substance
thereof.

         The quorum at any meeting called to adopt a resolution shall be Holders
representing a majority in aggregate principal amount of Securities at the time
Outstanding.

         SECTION 7.3     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 5.1 and 5.3) shall be fully protected in relying upon,
                ------------     ---
an Opinion of Counsel stating that the execution of such supplemental indenture
is authorized or permitted by this Indenture 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 that affects the
Trustee's own rights, duties or immunities under this Indenture or otherwise.

         SECTION 7.4     Effect of Supplemental Indentures.
                         ---------------------------------

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

         SECTION 7.5     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

                                     -46-
<PAGE>

the Company and authenticated and delivered by the Trustee in exchange for
Outstanding Securities.

         SECTION 7.6     Notice of Supplemental Indentures.
                         ---------------------------------

         Promptly after the execution by the Company and the Trustee of any
supplemental indenture pursuant to the provisions of Section 7.2, the Company
                                                     -----------
shall give notice to all Holders of Securities 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 EIGHT

                                   COVENANTS

         SECTION 8.1     Payment of Principal, Premium and Interest.
                         ------------------------------------------

         The Company covenants and agrees that it will duly and punctually pay
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
shall deposit or cause to be deposited with the Trustee, no later than 12:00
noon Eastern time on the date of the Stated Maturity of any Security or no later
than 12:00 noon Eastern time 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.

         SECTION 8.2     Maintenance of Offices or Agencies.
                         ----------------------------------

         The Company hereby appoints the Corporate Trust Office or such other
office or agency of the Trustee as its agent in the Borough of Manhattan, The
City of New York, where Securities may be presented or surrendered for payment,
where Securities may be surrendered for registration of transfer or exchange,
where Securities may be surrendered for conversion, and where notices and
demands to or upon the Company in respect of the Securities and this Indenture
may be served.

         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 8.3, the Company shall 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, 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 shall give prompt written notice to the Trustee, and

                                     -47-
<PAGE>

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.

         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,
presentations and surrenders may be made and notices and demands may be served
on the Corporate Trust Office.

         SECTION 8.3     Money for Security Payments to Be Held in Trust.
                         -----------------------------------------------

         If the Company will act as its own Paying Agent, it shall, 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.

         Whenever the Company shall have one or more Paying Agents, it will, no
later than 12:00 noon Eastern time on each due date of the principal of,
premium, if any, or interest on any Securities, deposit with the Trustee a sum
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 8.3,
                                                                -----------
that such Paying Agent will:

         (a)      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;

         (b)      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

         (c)      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.

         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.

                                     -48-
<PAGE>

         Anything contained herein to the contrary notwithstanding, any money
held by the Trustee or any Paying Agent in trust for the payment and discharge
of the principal of, premium, if any, Liquidated Damages, if any, or interest on
any Security that remains unclaimed for two years after the date when each
payment of such principal, premium, Liquidated Damages, if any, or interest has
become payable shall, upon the request of the Company, be repaid by the Trustee
to the Company as its absolute property free from trust, and the Trustee shall
thereupon be released and discharged with respect thereto and the Holders shall
look only to the Company for the payment of the principal, premium or interest
on such Security. The Trustee shall not be liable to the Company or any Holder
for interest on funds held by it for the payment and discharge of the principal,
premium or interest on any of the Securities to any Holder. 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.

         SECTION 8.4     Existence.
                         ---------

         Subject to Article Six, 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
Board of Directors shall determine that the preservation thereof is no longer
desirable in the conduct of the business of the Company and that the loss
thereof is not disadvantageous in any material respect to the Holders.

         SECTION 8.5     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 (one of the signers of which shall be the Company's principal
executive, principal financial or principal accounting officer), 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 have knowledge.

         The Company will deliver to the Trustee, forthwith upon becoming aware
of any default in the performance or observance of any covenant, agreement or
condition contained in this Indenture, or any Event of Default, 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.

         Any notice required to be given under this Section 8.5 shall be
                                                    -----------
delivered to the Trustee at the Corporate Trust Office.

         SECTION 8.6     Delivery of Certain Information.
                         -------------------------------

         At any time when the Company is not subject to Section 13 or 15(d) of
the Exchange Act, upon the request of a Holder of a Security or the holder of
shares of Common Stock issued upon

                                     -49-
<PAGE>

conversion thereof, the Company will promptly furnish or cause to be furnished
Rule 144A Information to such Holder of Securities or such holder of shares of
Common Stock issued upon conversion of Securities, or to a prospective purchaser
of any such security designated by any such Holder or holder, as the case may
be, to the extent required to permit compliance by such Holder or holder with
Rule 144A under the Securities Act (or any successor provision thereto) in
connection with the resale of any such security; provided, however, that the
Company shall not be required to furnish such information in connection with any
request made on or after the date that is two years from the later of (a) the
date such a security (or any such predecessor security) was last acquired from
the Company or (b) the date such a security (or any such predecessor security)
was last acquired from an "affiliate" of the Company within the meaning of Rule
144 under the Securities Act (or any successor provision thereto). "Rule 144A
                                                                    ---------
Information" shall be such information as is specified pursuant to Rule 144A(d)
-----------
(4) under the Securities Act (or any successor provision thereto).

                                 ARTICLE NINE

                           REDEMPTION OF SECURITIES

     SECTION 9.1    Right of Redemption.
                    -------------------

     The Securities may be redeemed in accordance with the provisions of the
form of Securities attached hereto as Exhibit A.
                                      ---------

     SECTION 9.2    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 Nine.
                                                         ------------

     SECTION 9.3    Election to Redeem; Notice to Trustee.
                    -------------------------------------

     In case of any redemption at the election of the Company of any of the
Securities, the Company shall, at least 35 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 9.4    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 at least three
Business Days prior to the date that the notice described in Section 9.5 is
                                                             -----------
given from the Outstanding Securities not previously called for redemption by
lot or such method as the Trustee may deem fair and appropriate.

     If any Registered 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

                                     -50-
<PAGE>

for redemption. Securities that 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.

     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 that has been or is to be redeemed.

     SECTION 9.5    Notice of Redemption.
                    --------------------

     Notice of redemption shall be given in the manner provided in Section 1.6
                                                                   -----------
to the Holders of Securities 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 identify the Securities to be redeemed
(including CUSIP numbers) and shall state:

     (a)  the Redemption Date,

     (b)  the Redemption Price, and accrued interest, if any,

     (c)  if less than all Outstanding Securities are to be redeemed, the
aggregate principal amount of Securities to be redeemed,

     (d)  that on the Redemption Date the Redemption Price, and accrued
interest, if any, 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,

     (e)  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, and

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

     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.

     SECTION 9.6    Deposit of Redemption Price.
                    ---------------------------

                                    -51-
<PAGE>

     Not less than one Business Day prior to 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 Section 8.3) 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 on, all the Securities that
are to be redeemed on that date other than any Securities called for redemption
on that date that have been converted prior to the date of such deposit.

     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 or such Security or any
Predecessor Security to receive interest as provided in the last paragraph of
Section 2.8) be paid to the Company on Company Request or, if then held by the
-----------
Company, shall be discharged from such trust.

     SECTION 9.7    Securities Payable on Redemption Date.
                    -------------------------------------

     Notice of redemption having been given as aforesaid, the Securities to be
so 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 2.8.
                                     -----------

     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 the rate then in effect,
and such Security shall remain convertible until the principal of such Security
(or portion thereof, as the case may be) shall have been paid or duly provided
for.

    SECTION 9.8     Securities Redeemed in Part.
                    ---------------------------

    Any Security that is to be redeemed only in part shall be surrendered at an
office or agency of the Company designated for that purpose pursuant to Section
                                                                        -------
8.2 (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 without service
charge, a new Registered 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.

                                     -52-
<PAGE>

     SECTION 9.9    Conversion Arrangement on Call for Redemption.
                    ---------------------------------------------

     In connection with any redemption of the 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
                                                                       -------
Nine, 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 second 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 this Article Nine) 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 loss,
liability or expense arising out of or in connection with any such arrangement
for the purchase and conversion of any Securities between the Company and such
Purchasers, including the costs and expenses, 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.

                                  ARTICLE TEN

                           CONVERSION OF SECURITIES

     SECTION 10.1   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 or any portion of the principal
amount thereof that is U.S.$l,000 or an integral multiple of U.S.$1,000 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
of the Securities and expire at the close of business on June 15, 2008, unless
the Security has been previously redeemed or repurchased, subject, in the case
of conversion of any Global Security, to any

                                     -53-
<PAGE>

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 29.4118 shares of
                    ---------------
Common Stock for each U.S.$l,000 principal amount of Securities. The Conversion
Rate shall be adjusted in certain instances as provided in this Article Ten.
                                                                -----------

     SECTION 10.2   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 or assigned to the
Company or in blank, at any office or agency of the Company maintained for that
purpose pursuant to Section 8.2, accompanied by a duly signed and completed
                    -----------
conversion notice substantially in the form attached hereto as Exhibit C 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 period from the close of business on any Regular Record Date next preceding
any Interest Payment Date to the opening of business on such Interest Payment
Date shall (except in the case of any Security or portion thereof that has been
called for redemption on a Redemption Date, or is to be repurchased on a
Repurchase Date, with the consequence that the conversion right of such Security
would terminate between such Regular Record Date and the close of business on
such Interest Payment Date) 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) that is surrendered for conversion
during the period from the close of business on any Record Date next preceding
any Interest Payment Date to the opening of business on such Interest Payment
Date, shall be paid to the Holder of such Security as of such Regular Record
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 2.8, 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 and any
rights and warrants pursuant to Section 10.4(m) will be deemed to satisfy the
                                ---------------
Company's obligation to pay the principal amount of the Security.

                                     -54-
<PAGE>

     Securities shall be deemed to have been converted 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 10.3.
                                           ------------

     All shares of Common Stock delivered upon such conversion of Securities
shall bear restrictive legends substantially in the form of the legends required
to be set forth on the Securities pursuant to Section 2.6 and shall be subject
                                              -----------
to the restrictions on transfer provided in such legends. Neither the Trustee
nor any agent maintained for the purpose of such conversion shall have any
responsibility for the inclusion or content of any such restrictive legends on
such Common Stock; provided, however, that the Trustee or any agent maintained
for the purpose of such conversion shall have provided to the Company or to the
Company's transfer agent for such Common Stock, prior to or concurrently with a
request to the Company to deliver such Common Stock, written notice that the
Securities delivered for conversion are Securities.

     In the case of any Security that is converted in part only, upon such
conversion the Company shall execute and the Trustee shall authenticate and make
available for delivery to the Holder thereof, at the expense of the Company, a
new Registered 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 any integral multiple of
U.S.$1,000 and the principal amount of such security to remain Outstanding after
such conversion is equal to U.S.$l,000 or any integral multiple of U.S.$l,000 in
excess thereof.

     SECTION 10.3   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 that 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 that 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 Average Sales Price Per
Share at the close of business on the day of conversion.

     SECTION 10.4   Adjustment of Conversion Rate.
                    -----------------------------

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

                                     -55-
<PAGE>

     (a)  In case the Company shall pay or make a dividend or other distribution
on 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 (subject to paragraph (l) of this Section
                                                                    -------
10.4) immediately after the opening of business on the day following the date
----
fixed for such determination. For the purposes of this paragraph (a), 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.

     (b)  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 (h) of this Section 10.4) 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 (1) 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 or (2) that are only exercisable upon the
occurrence of specified triggering event and such triggering event has not
occurred), 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 (subject to paragraph (l) of this Section 10.4) immediately
                                                      ------------
after the opening of business on the day following the date fixed for such
determination. For the purposes of this paragraph (b), 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.

     (c)  In case 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
outstanding shares of Common Stock shall each 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 combination becomes
effective shall be proportionately reduced, such increase or reduction, as the
case may

                                     -56-
<PAGE>

be, to become effective immediately after the opening of business on the day
following the day upon which such subdivision or combination becomes effective.

     (d)  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 (1) any rights, options or warrants referred to in paragraph (b) of
this Section 10.4 and the distribution of rights to all holders of Common Stock
     ------------
pursuant to the adoption of a stockholders' rights plan or the detachment of
such rights under the terms of such stockholders' rights plan, (2) any dividend
or distribution paid in cash, except as set forth in paragraphs (e) and (f) of
this Section 10.4, (3) any dividend or distribution referred to in paragraph (a)
     ------------
of this Section 10.4 and (4) any merger or consolidation to which Section 10.11
        ------------                                              -------------
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 (h)
of this Section 10.4) 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) 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 (subject to paragraph (l) of this Section 10.4) immediately
                                                   ------------
prior to the opening of business on the day following the date fixed for the
determination of stockholders entitled to receive such distribution.

     Under the provisions of the Company's Rights Agreement dated as of November
11, 1996 (the "Rights Plan"), between the Company and Harris Trust Company of
               -----------
California, upon conversion of the Securities into Common Stock, to the extent
that the Rights Plan is still in effect upon such conversion, the Holders of
Securities will receive, in addition to the Common Stock, the rights described
therein (whether or not the rights have separated from the Common Stock at the
tine of conversion), subject to the limitations set forth in the Rights Plan. In
addition, if the Company implements a new rights plan ("New Rights Plan"), the
                                                        ---------------
Company will provide under such New Rights Plan that the Holders of the
Securities will receive, in addition to the Common Stock, the rights under the
New Rights Plan (whether or not the rights under the New Rights Plan have
separated from the Common Stock at the time of conversion), subject to any
limitations set forth in the New Rights Plan.

     (e)  In case the Company shall, by dividend or otherwise, distribute to all
holders of its Common Stock cash (excluding cash portions of distribution
referred to in Section 10.4(d) and any cash that is distributed upon a merger or
               --------------
consolidation to which Section 10.11 applies) in an aggregate amount that,
                       -------------
combined together with (1) the aggregate amount of any other cash distributions
to all holders of its Common Stock made exclusively in 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 (e) has been made and (2) 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 Subsidiary for all or any portion of the Common Stock concluded
within the

                                     -57-
<PAGE>

365-day period preceding the date of payment of such distribution and in respect
of which no adjustment pursuant to paragraph (f) of this Section 10.4 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 (h) of this
Section 10.4) 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, subject to paragraph (l) of Section
                                                                     -------
10.4, 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 (A) the numerator of which
shall be equal to the current market price per share (determined as provided in
paragraph (h) of this Section 10.4) of the Common Stock on the date fixed for
                      ------------
such determination less an amount equal to the quotient of (i) the excess of
such combined cash and tender amount over 10% of such aggregate current market
price divided by (ii) the number of shares of Common Stock outstanding on such
date fixed for determination and (B) the denominator of which shall be equal to
the current market price per share (determined as provided in paragraph (h) of
this Section 10.4) of the Common Stock on such date fixed for determination.
     ------------

     (f)  In case a tender offer made by the Company or any Subsidiary for all
or any portion of the Common Stock shall be completed for an aggregate
consideration consisting of cash and/or property 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 (1) 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), 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
concluded within the 365-day period preceding the completion of such tender
offer and in respect of which no adjustment pursuant to this paragraph (f) has
been made and (2) the aggregate amount of any distributions to all holders of
the Company's Common Stock made exclusively in cash within the 365-day period
preceding the completion of such tender offer and in respect of which no
adjustment pursuant to paragraph (e) of this Section 10.4 has been made (the
                                             ------------
"combined tender and cash amount") exceeds 10% of the product of the current
 -------------------------------
market price per share of the Common Stock (determined as provided in paragraph
(h) of this Section 10.4) as of the completion of such tender offer (the
            ------------
"Completion Date") times the number of shares of Common Stock outstanding
 ---------------
(including any tendered shares) as of the Completion Date, then, and in each
such case, immediately prior to the opening of business on the day after the
date of the Completion Date, 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 Completion Date by a fraction (A) the
numerator of which shall be equal to (i) the product of (x) the current market
price per share of the Common Stock (determined as provided in paragraph (h) of
this Section 10.4) on the Completion Date multiplied by (y) the number of shares
     ------------
of Common Stock outstanding (including any tendered shares) on the Completion
Date less (ii) the combined tender and cash amount, and (B) the denominator of
which shall be equal to the product of (x) the current market price per share of
the Common Stock (determined as provided in paragraph (h) of this Section 10.4)
                                                                  ------------
as of the Completion Date multiplied by (y) the number of shares of Common Stock
outstanding

                                     -58-
<PAGE>

(including any tendered shares) as of the Completion Date less the number of all
shares validly tendered and not withdrawn as of the Completion Date (the shares
deemed so accepted up to any such maximum, being referred to as the "Purchased
                                                                     ---------
Shares").
------

     (g)  The reclassification of Common Stock into securities including other
than Common Stock (other than any reclassification upon a consolidation or
merger to which Section 10.11 applies) shall be deemed to involve (1) 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 (d) of this Section 10.4), and (2) 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 (c) of this Section 10.4).
                                                               ------------

     (h)  For the purpose of any computation under paragraphs (b), (d), (e) or
(f) of this Section 10.4, 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 Average Sales 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 regular way in the applicable securities market or on the
applicable securities exchange without the right to receive such issuance or
distribution.

     (i)  No adjustment in the Conversion Rate shall be required unless such
adjustment (plus any adjustments not previously made by reason of this paragraph
(i)) 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 (i)
are not required to be made shall be carried forward and 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.

     (j)  The Company may 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 (a), (b), (c), (d), (e) and (f) of this Section 10.4, 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 Common Stock or issuance of rights or warrants to purchase or
subscribe for Common Stock or from any event treated as such for income tax
purposes.

     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

                                     -59-
<PAGE>

the best interests of the Company, which determination shall be conclusive;
provided, however, that such increase shall not be taken into account for
purposes of determining whether the Average Sales Price Per Share of the Common
Stock exceeds the Conversion Price by 105% in connection with an event which
would otherwise be a Change in Control. Whenever the Conversion Rate is
increased pursuant to the preceding sentence, the Company shall give notice of
the increase to the Holders of Securities 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.

     (k)  Notwithstanding the foregoing provisions of this Section 10.4, no
                                                           ------------
adjustment of the Conversion Rate shall be required to be made (1) upon the
issuance of shares of Common Stock pursuant to any present or future plan for
the reinvestment of dividends, (2) 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 or (3) as a result of a rights plan or poison pill implemented by
the Company.

     (l)  In any case in which this Section 10.4 shall require that an
                                    ------------
adjustment be made immediately following a record date, the Company may elect to
defer the effectiveness of such adjustment (but in no event until a date later
than the effective time of the event giving rise to such adjustment), in which
case the Company shall, with respect to any Security converted after such record
date and on and before such adjustment shall have become effective (1) defer
paying any cash payment pursuant to Section 10.3 hereof or issuing to the Holder
                                    ------------
of such Security the number of shares of Common Stock issuable upon such
conversion in excess of the number of shares of Common Stock issuable thereupon
only on the basis of the Conversion Rate prior to adjustment, and (2) not later
than five Business Days after such adjustment shall have become effective, pay
to such Holder the appropriate cash payment pursuant to Section 10.3 hereof and
                                                        ------------
issue to such Holder the additional shares of Common Stock issuable on such
conversion. Notwithstanding the foregoing, no adjustment of the Conversion Rate
shall be made if the event giving rise to such adjustment does not occur.

     (m)  In the event that the Company distributes rights or warrants (other
than those referred to in paragraph (b) above) pro rata to holders of Common
Stock, so long as any such rights or warrants have not expired or been redeemed
by the Company, the Company shall make proper provision so that the Holder of
any Security surrendered for conversion will be entitled to receive upon such
conversion, in addition to the Common Stock issuable upon conversion of the
Securities (the "Conversion Shares"), a number of rights and warrants to be
                 -----------------
determined as follows: (i) if such conversion occurs on or prior to the date for
the distribution to the holders of rights or warrants of separate certificates
evidencing such rights or warrants (the "Distribution Date"), the same number of
                                         -----------------
rights or warrants to which a holder of a number of shares of Common Stock equal
to the number of Conversion Shares is entitled at the time of such conversion in
accordance with the terms and provisions of and applicable to the rights or
warrants, and (ii) if such conversion occurs after such Distribution Date, the
same number of rights or warrants to which a holder of the number of shares of
Common Stock into which the principal amount of such Security so converted was
convertible immediately prior to such Distribution Date would have been entitled
on such Distribution Date in accordance with the terms and provisions of and
applicable to the rights or warrants.

                                     -60-
<PAGE>

          SECTION 10.5     Notice of Adjustments of Conversion Rate.
                           ----------------------------------------

          Whenever the Conversion Rate is adjusted as herein provided:

          (a)  the Company shall compute the adjusted Conversion Rate in
accordance with Section 10.4 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 the
Conversion Agent; and

          (b)  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.
                                                          -----------

Neither the Trustee nor the 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 of
Securities desiring inspection thereof at its office during normal business
hours. Unless and until a Responsible Officer of the Trustee and Conversion
Agent receive notice of an adjusted Conversion Rate, the Trustee and the
Conversion Agent may rely without inquiry on the Conversion Rate most recently
in effect.

          SECTION 10.6     Notice of Certain Corporate Action.
                           ----------------------------------
          In case:

          (a)  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 10.4; or
------------

          (b)  the Company shall authorize the granting to 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

          (c)  of any reclassification of the Common Stock of the Company, 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

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

then the Company shall cause to be filed at each office or agency maintained for
the purpose of conversion of Securities pursuant to Section 8.2, 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 (a) or (b)

                                     -61-

<PAGE>

above) prior to the applicable record or effective date hereinafter specified, a
notice stating (1) 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 (2) 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
(a) through (d) of this Section 10.6. If at the time the Trustee shall not be
                        ------------
the Conversion Agent, a copy of such notice shall also forthwith be filed by the
Company with the Trustee.

          The Company shall cause to be filed at each office or agency
maintained for the purpose of conversion of Securities pursuant to Section 8.2,
                                                                   -----------
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 10.7     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 10.8    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 10.9    Covenant as to Common Stock.
                          ---------------------------

          The Company agrees that all shares of Common Stock that may be
delivered upon conversion of Securities, upon such delivery, will be newly
issued shares and will have been duly authorized and validly issued and will be
fully paid and nonassessable and, except as provided in Section 10.8, the
                                                        ------------
Company will pay all taxes, liens and charges with respect to the issue thereof.

                                     -62-

<PAGE>

          SECTION 10.10   Cancellation of Converted Securities.
                          ------------------------------------

          All Securities delivered for conversion shall be delivered to the
Trustee or its agent to be cancelled by or at the direction of the Trustee,
which shall dispose of the same as provided in Section 2.10.
                                               ------------

          SECTION 10.11   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 that does not result in any reclassification, conversion, exchange or
cancellation of outstanding shares of Common Stock of the Company) or any
conveyance, sale, transfer or lease of all or substantially all of the assets of
the Company, the Person formed by such consolidation or resulting from such
merger or that 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 1l.l, 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 (a) is not a Person with which the Company
consolidated or merged with or into or that merged into or with the Company or
to which such conveyance, sale, transfer or lease was made, as the case may be
(a "Constituent Person"), or an Affiliate of a Constituent Person and (b) 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
                 ------------------                                 -------
10.11 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 that, 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 10.11 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 the 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 of
Securities upon the conversion of their Securities after any such

                                     -63-
<PAGE>

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
an Opinion of Counsel with respect thereto, which the Company shall cause to be
furnished to the Trustee upon request.

          SECTION 10.12    Responsibility of Trustee for Conversion Provisions.
                           ---------------------------------------------------

          The Trustee, subject to the provisions of Section 5.1, and any
                                                    -----------
Conversion Agent shall not at any time be under any duty or responsibility to
any Holder of Securities to determine whether any facts exist that 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 5.1, 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,
that 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 5.1, nor any Conversion Agent
                                      -----------
shall be responsible for any failure of the 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 5.1, 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.

                                ARTICLE ELEVEN

                          SUBORDINATION OF SECURITIES

          SECTION 11.1     Securities Subordinate to Senior Debt.
                           -------------------------------------

          The Company covenants and agrees, and each Holder of a Security by his
acceptance thereof likewise covenants and agrees, that to the extent and in the
manner hereinafter set forth in this Article (subject to the provisions of
Article Three) the indebtedness represented by the Securities and the payment of
-------------
the principal of (and premium, if any) and interest on, and any payment of the
Repurchase Price with respect to, each and all of the Securities are hereby
expressly made subordinate and subject in right of payment to the prior payment
in full in cash or Cash Equivalents of all Senior Debt.

          SECTION 11.2    No Payments in Certain Circumstances; Payment Over of
                          -----------------------------------------------------
                          Proceeds Upon Dissolution, Etc.
                          ------------------------------

          No payment on account of principal of, premium, if any, or interest
(and Liquidated Damages, if any) on, or redemption or repurchase of, the
Securities shall be made if, at the time of such payment: (a) a default in the
payment of principal, premium, if any, or interest or other amounts due on or in
connection with any Senior Debt, including any default under any redemption or
repurchase obligation, 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

                                     -64-
<PAGE>

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 (b) a default, other than a payment default, on
Designated Senior Debt occurs and is continuing that then permits holders of
such Designated Senior Debt to accelerate its maturity and the Trustee receives
a notice of the default (a "Payment Blockage Notice") from the Company, a holder
                            -----------------------
of Designated Senior Debt or a Representative. Notwithstanding the foregoing,
the Company may make, and the Trustee may receive and shall apply, any payment
in respect of the Securities (for principal, premium, if any, or interest (and
Liquidated Damages, if any) or repurchase) if such payment was made prior to the
occurrence of any of the contingencies specified in clauses (a) and (b) above.

         If the Trustee receives any Payment Blockage Notice pursuant to clause
(b) above, no subsequent Payment Blockage Notice shall be effective for purposes
of this Section 11.2 unless and until (1) at least 365 days shall have elapsed
        ------------
since the effectiveness of the immediately prior Payment Blockage Notice and (2)
all scheduled payments of principal, premium, if any, interest and Liquidated
Damages, if any, on the Securities that have come due have been paid in full in
cash. 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 unless such existing nonpayment
default has been cured for a period of at least 90 days.

         The Company may and shall resume payments on and distributions in
respect of the Securities (including missed payments, if any) upon the earlier
of: (A) the date upon which the default is cured or waived, or (B) in the case
of a default referred to in clause (b) of the second preceding paragraph, 179
days after notice is received if the maturity of such Designated Senior Debt has
not been accelerated such that such debt is then presently payable, unless this
Indenture otherwise prohibits the payment or distribution at the time of such
payment or distribution.

         Upon (i) any acceleration of the principal amount due on the Securities
or (ii) any payment or distribution of assets of the Company of any kind or
character, whether in cash, property or securities, to creditors upon any
dissolution, winding up or total or partial liquidation or reorganization of the
Company, whether voluntary or involuntary, or in bankruptcy, insolvency,
receivership or other proceedings, all principal of, premium, if any, sinking
fund and interest or other amounts due, or to become due, upon or in connection
with all Senior Debt shall first be paid in full in cash or Cash Equivalents, or
payment thereof provided for in cash or Cash Equivalents in accordance with its
terms, before any payment is made on account of the principal of, premium, if
any, or interest (and Liquidated Damages, if any) on, or repurchase of, the
indebtedness evidenced by the Securities, and upon any such dissolution or
winding up or liquidation or reorganization any payment or distribution of
assets of the Company of any kind or character, whether in cash, property or
securities, to which the Holders of the Securities or the Trustee under this
Indenture would be entitled, except for the provisions hereof, shall be paid by
the Company or by any receiver, trustee in bankruptcy, liquidating trustee,
agent or other Person making such payment or distribution, or by the Holders of
the Securities or by the Trustee under this Indenture if received by them or it,
as the case may be, directly to the holders of Senior Debt (pro rata to each
such holder on the basis of the respective amounts of Senior Debt held by such
holder) or their representatives, to the extent necessary to pay all Senior Debt
in full, in cash or

                                     -65-
<PAGE>

Cash Equivalents, after giving effect to any concurrent payment or distribution
to or for the holders of Senior Debt, before any payment or distribution is made
to the Holders of the Securities or to the Trustee under this Indenture.

          In the event that, contrary to the foregoing, any payment or
distribution of assets of the Company of any kind or character, whether in cash,
property or securities (other than junior securities, as defined in Section
                                                                    -------
11.11), shall be received by the Trustee or the Holders of the Securities before
-----
all Senior Debt is paid in full in cash or Cash Equivalents or provision made
for such payment in accordance with its terms, such payment or distribution
shall be paid over or delivered to the holders of such Senior Debt or their
representative or representatives, or to the trustee or trustees under any
indenture pursuant to which any instruments evidencing any of such Senior Debt
have been issued, as their respective interests may appear, for application to
the payment of all Senior Debt remaining unpaid to the extent necessary to pay
all such Senior Debt in full in cash or Cash Equivalents in accordance with its
terms, after giving effect to any concurrent payment or distribution to or for
the holders of such Senior Debt.

          Subject to the payment in full in cash or Cash Equivalents of all
Senior Debt, the Holders of the Securities (together with the holders of any
other indebtedness of the Company that is subordinated in right of payment to
the payment in full of all Senior Debt that is not subordinated in right of
payment to the Securities and that by its terms grants such right of subrogation
to the holders thereof) shall be subrogated to the rights of the holders of
Senior Debt to receive payments or distribution of assets of the Company made on
the Senior Debt until the principal of, premium, if any, and interest on, or
amounts payable upon repurchase of, the Securities shall be paid in full; and,
for the purposes of such subrogation, no payments or distributions to the
holders of 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 payment over pursuant to the provisions of this Article to
the holders of Senior Debt by the Holders of the Securities or the Trustee,
shall, as between the Company, its creditors other than the holders of Senior
Debt, and the Holders of Securities, be deemed to be a payment by the Company to
the holders of or on account of Senior Debt, it being understood that 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.

          SECTION 11.3     Trustee to Effectuate Subordination.
                           -----------------------------------

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

          SECTION 11.4     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

                                     -66-
<PAGE>

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: (a) 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; (b) sell,
exchange, release or otherwise deal with any property pledged, mortgaged or
otherwise securing Senior Debt; (c) release any Person liable in any manner for
the collection of Senior Debt; and (d) exercise or refrain from exercising any
rights against the Company and any other Person.

          SECTION 11.5     Notice to Trustee.
                           -----------------

          The Company shall give prompt written notice to the Trustee of any
fact known to the Company that 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 that 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 holder of Senior Debt or from any trustee,
agent or representative therefor; and, prior to the receipt of any such written
notice, the Trustee, subject to the provisions of Section 5.1, 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 11.5
                                                                    ------------
prior to the date upon which by the terms hereof any money may become payable
for any purpose (including without limitation the payment of the principal of
(and premium, 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
that may be received by it within two Business Days prior to such date.

          Subject to the provisions of Section 5.1, the Trustee shall be
                                       -----------
entitled to rely on the delivery to it of a written notice by a Person
representing himself to be a holder of Senior Debt (or a trustee, agent or
representative therefor) to establish that such notice has been given by a
holder of Senior Debt (or a trustee, agent or representative therefor). In the
event that the Trustee determines in good faith that further evidence is
required with respect to the right of any Person as a holder of Senior Debt to
participate in any payment or distribution pursuant to this Article Eleven, 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 Eleven, and if such evidence is not
     ------- ------

                                     -67-
<PAGE>

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 11.6     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 5.1, 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 of Securities, 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 11.7     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 distribute to Holders of Securities 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 the 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 Eleven, and no implied covenants or obligations with
              ------- ------
respect to holders of Senior Debt shall be read into this Indenture against the
Trustee.

          SECTION 11.8     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. Such holders of the Company's Senior Debt are
intended by the parties to the Indenture to be third party creditor
beneficiaries under this Indenture for the purposes of enforcing the provisions
of this Article Eleven.
        ------- ------

          SECTION 11.9     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 Eleven with respect to any Senior Debt that may
                         ------- ------
at any time be held by it, to the same

                                     -68-
<PAGE>

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 Eleven shall apply to claims of, or payments
                          --------------
to, the Trustee under or pursuant to Section 5.7.
                                     -----------

          SECTION 11.10    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 Eleven in addition to or in place of the Trustee;
              ------- ------
provided, however, that Section 11.9 shall not apply to the Company or any
                        ------------
Affiliate of the Company if it or such Affiliate acts as Paying Agent.

          SECTION 11.11    Certain Conversions and Repurchases Deemed Payment.
                           --------------------------------------------------

          For the purposes of this Article Eleven only, (a) the issuance and
                                   --------------
delivery of junior securities upon conversion of Securities in accordance with
Article Ten or upon the repurchase of Securities in accordance with Article
-----------                                                         -------
Twelve shall not be deemed to constitute a payment or distribution on account of
------
the principal of or premium or interest or Liquidated Damages on Securities or
on account of the purchase or other acquisition of Securities, and (b) the
payment, issuance or delivery of cash, property or securities (other than junior
securities) upon conversion of a Security shall be deemed to constitute payment
on account of the principal of such Security. For the purposes of this Section
                                                                       -------
11.11, the term "junior securities" means (1) shares of any stock of any class
-----
of the Company and any cash, property or securities into which the Securities
are convertible pursuant to Article Ten and (2) securities of the Company that
                            -----------
are subordinated in right of payment to all Senior Debt that 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 Eleven. Nothing contained in this Article Eleven 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
                                                                       -------
Ten or to exchange such Security for Common Stock in accordance with Article
---                                                                  -------
Twelve if the Company elects to satisfy the obligations under Article Twelve by
------                                                        --------------
the delivery of Common Stock.

                                     -69-
<PAGE>

                                 ARTICLE TWELVE

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

         SECTION 12.1     Right to Require Repurchase.
                          ---------------------------

         In the event that a Change in Control shall occur, then each Holder
shall have the right, at the Holder's option, but subject to the provisions of
Section 12.2, 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 is equal to U.S.$1,000 or any greater integral multiple of
U.S.$1,000, on the date (the "Repurchase Date") that is fixed by the Company at
                              ---------------
a cash purchase price equal to 100% 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 2.8. The Repurchase Date will be determined by the Company in the
-----------
following manner: (i) the Company will give notice of the Change in Control as
contemplated in Section 12.3(a); (ii) each Holder electing to exercise the
repurchase right must deliver, on or before the thirtieth (30th) day (or such
greater period as may be required by applicable law) after the date of the
Company's notice provided in provision (i) above: (A) irrevocable written notice
to the trustee of such Holder's exercise of its repurchase right, and (B) the
Securities with respect to which such repurchase right is being exercised; and
(iii) the Company will make the repurchase on a date that is no later than 45
days after the Holder has delivered the notice provided in proviso (ii) above.
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 Three 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 12.2, by delivery of shares of Common Stock or in a
          ------------
combination of cash and Common Stock having a fair market value equal to the
Repurchase Price. Whenever in this Indenture (including Sections 2.2, 4.1(a) and
                                                        --------------------
4.8) 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 that has become and remains 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 Eleven such reference shall be deemed
                                  --------------
to include reference to the Repurchase Price only to the extent the Repurchase
Price is payable in cash.

         For purposes of this Section 12.1, the fair market value of shares of
                              ------------
Common Stock shall be determined by the Company and shall be equal to 95% of the
average of the closing price per share of the Common Stock or the principal
exchange on which the Common Stock is traded in

                                     -70-
<PAGE>

on The Nasdaq National Market for each of the five consecutive Trading Days
immediately preceding and including the third Trading Day prior to the
Repurchase Date.

         SECTION 12.2     Conditions to the Company's Election to Pay the
                          -----------------------------------------------
                          Repurchase Price in Common Stock.
                          --------------------------------

         The Company may elect to pay the Repurchase Price by delivery of shares
of Common Stock pursuant to Section 12.1 if and only if the following conditions
                            ------------
shall have been satisfied:

         (a) As to each Holder, the Repurchase Price shall be paid only in cash
in the event any shares of Common Stock to be issued to such Holder upon
repurchase of Securities hereunder (1) 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 (2) 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 and if such
registration is not completed or does not become effective or such approval is
not obtained prior to the Repurchase Date;

         (b) Payment of the Repurchase Price 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 or quoted on a national securities exchange or other
quotation system, in either case, prior to the Repurchase Date; and

         (c) All shares of Common Stock that may be issued upon repurchase of
Securities will be issued out of the Company's authorized but unissued Common
Stock will and, upon issue, be duly and validly issued and fully paid and
non-assessable and free of any preemptive rights.

         If all of the conditions set forth in this Section 12.2 are not
                                                    ------------
satisfied in accordance with the terms thereof, the Repurchase Price shall be
paid by the Company only in cash.

         SECTION 12.3     Notices; Method of Exercising Repurchase Right, Etc.

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

         Each notice of a repurchase right shall state:

             (1) the Repurchase Date,

                                     -71-
<PAGE>

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

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

             (4) a description of the procedure that 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,

             (5) that on the Repurchase Date, the Repurchase Price, and accrued
         interest, if any, 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,

             (6) 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,

             (7) the place or places that the Notice of Election of Holder to
         Require Repurchase attached hereto as Exhibit B, shall be delivered,
                                               ---------
         and the form of such notice, and

             (8) the CUSIP number or numbers of such Securities.

         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
                                                                        -------
Twelve are inconsistent with applicable law, such law shall govern.
------

         (b) To exercise a repurchase right, a Holder shall deliver to the
Trustee on or before the thirtieth day (or such greater period as may be
required by applicable law) after the date of the Company Notice (1) 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 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
(2) 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.

                                     -72-
<PAGE>

         (c) In the event 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 purchase 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.

         (d) 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 then in effect 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.

         (e) Any Security that 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.

         (f) 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 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.

         (g) 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 that 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 that 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

                                     -73-
<PAGE>

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 12.3, the current market price of a share of Common
                 ------------
Stock is the average of the high and low sales price per Share of the Common
Stock on the Trading Day immediately preceding the Repurchase Date.

         (h) Any issuance and delivery of certificates for shares of Common
Stock on repurchase of Securities shall be made without charge to the Holder of
Securities 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 that may be payable in respect of (1) income of the
Holder or (2) 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
satisfaction of the Company, that such tax or duty has been paid.

         (i) 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 2.10.
                        ------------

                                ARTICLE THIRTEEN

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

         SECTION 13.1 Company to Furnish Trustee Names and Addresses of Holders.
                      ---------------------------------------------------------

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

         (a) 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 of Securities as of such Regular Record Date, and

         (b) 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;

provided, however, that no such list need be furnished so long as the Trustee is
acting as Security Registrar.

         SECTION 13.2     Preservation of Information.
                          ---------------------------

         (a) 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 13.1 and the names and
                                             ------------
addresses of Holders received by the Trustee in its

                                     -74-
<PAGE>

capacity as Security Registrar. The Trustee may destroy any list furnished to it
as provided in Section 13.1 upon receipt of a new list so furnished.
               ------------

         (b) After this Indenture has been qualified under the Trust Indenture
Act, 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.

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

         SECTION 13.3     No Recourse Against Others.
                          --------------------------

         An incorporator or any past, present or future director, officer,
employee or stockholder, as such, of the Company shall not have any liability
for any obligations of the Company under the Securities or this Indenture or for
any claim based on, in respect of or by reason of such obligations or their
creation. By accepting a Security, each Holder shall waive and release all such
liability. Such waiver and release shall be part of the consideration for the
issue of the Securities.

         SECTION 13.4     Reports by Trustee.
                          ------------------

         (a) After this Indenture has been qualified under the Trust Indenture
Act, 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 therein. If required by
Section 313(a) of the Trust Indenture Act, the Trustee shall, within 60 days
after each May 15 following the date of this Indenture, deliver to Holders a
brief report, dated as of such May 15, that complies with the provisions of such
Section 313(a).

         (b) After this Indenture has been qualified under the Trust Indenture
Act, 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 promptly notify the Trustee when the Securities are listed on any stock
exchange.

         SECTION 13.5     Reports by Company.
                          ------------------

         After this Indenture has been qualified under the Trust Indenture Act,
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 therein; provided, however, that any such information,
documents or reports required to be filed with the Commission pursuant to
Section 13 or 15(d) of the Exchange Act shall be filed with the Trustee within
15 days after the same is so required to be filed with the Commission.

                                     -75-
<PAGE>

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

                                     -76-
<PAGE>

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

                              Cell Therapeutics, Inc.


                              By   /s/ Jim Bianco
                                 ------------------------------------------
                                 Name:  James A. Bianco, M.D.
                                 Title:  President and Chief Executive Officer

                              State Street Bank and Trust Company
                              of California, N.A.,
                              a national banking association, as Trustee


                              By  /s/ Scott C. Emmons
                                  --------------------------------------------
                                  Name: Scott C. Emmons
                                  Title:  Vice President

                                     -77-
<PAGE>

                                                                       EXHIBIT A

         [FORM OF FACE]

[THE FOLLOWING LEGEND SHALL APPEAR ON THE FACE OF EACH RESTRICTED SECURITY OTHER
THAN ANY RESTRICTED GLOBAL SECURITY:

         THIS NOTE AND ANY COMMON STOCK ISSUABLE UPON THE CONVERSION OF THIS
NOTE HAVE NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT OF 1933, AS AMENDED
(THE "SECURITIES ACT"), AND MAY NOT BE SOLD OR OTHERWISE TRANSFERRED IN THE
ABSENCE OF SUCH REGISTRATION OR AN APPLICABLE EXEMPTION THEREFROM. EACH
PURCHASER OF THIS NOTE IS HEREBY NOTIFIED THAT THE SELLER OF THIS NOTE MAY BE
RELYING ON THE EXEMPTION FROM THE PROVISIONS OF SECTION 5 OF THE SECURITIES ACT
PROVIDED BY RULE 144A THEREUNDER.

         THIS NOTE AND ANY COMMON STOCK ISSUABLE UPON CONVERSION OF THIS NOTE
MAY NOT BE OFFERED, SOLD, PLEDGED OR OTHERWISE TRANSFERRED EXCEPT (A)(1) TO A
PERSON WHO THE TRANSFEROR REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL BUYER
WITHIN THE MEANING OF RULE 144A UNDER THE SECURITIES ACT ACQUIRING FOR ITS OWN
ACCOUNT OR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER IN A TRANSACTION
MEETING THE REQUIREMENTS OF RULE 144A, (2) PURSUANT TO AN EXEMPTION FROM
REGISTRATION UNDER THE SECURITIES ACT PROVIDED BY RULE 144 THEREUNDER (IF
AVAILABLE), (3) TO AN INSTITUTIONAL INVESTOR THAT IS AN ACCREDITED INVESTOR
WITHIN THE MEANING OF RULE 501(A)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
SECURITIES ACT THAT PRIOR TO SUCH TRANSFER PROVIDES TO THE TRUSTEE FOR THE NOTES
A SIGNED LETTER CONTAINING CERTAIN REPRESENTATIONS AND AGREEMENTS RELATING TO
THE RESTRICTIONS ON TRANSFER OF THE NOTES (THE FORM OF THE LETTER CAN BE
OBTAINED FROM THE TRUSTEE OF THE NOTES), (4) PURSUANT TO ANOTHER EXEMPTION FROM
REGISTRATION UNDER THE SECURITIES ACT (IF AVAILABLE) (AND BASED UPON AN OPINION
OF COUNSEL ACCEPTABLE TO CELL THERAPEUTICS, INC.) OR (5) PURSUANT TO AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT, AND (B) IN ACCORDANCE
WITH ALL APPLICABLE SECURITIES LAWS OF THE STATES OF THE UNITED STATES AND OTHER
JURISDICTIONS.

         THIS NOTE, ANY SHARES OF COMMON STOCK ISSUABLE UPON ITS CONVERSION AND
ANY RELATED DOCUMENTATION MAY BE AMENDED OR SUPPLEMENTED FROM TIME TO TIME TO
MODIFY THE RESTRICTIONS ON RESALES AND OTHER TRANSFERS OF THIS NOTE AND ANY SUCH
SHARES TO REFLECT ANY CHANGE IN APPLICABLE LAW OR REGULATION (OR THE
INTERPRETATION THEREOF) OR IN PRACTICES RELATING TO THE RESALE OR TRANSFER OF
RESTRICTED SECURITIES GENERALLY. THE HOLDER OF

                                      A-1
<PAGE>

THIS NOTE AND SUCH SHARES SHALL BE DEEMED BY THE ACCEPTANCE OF THIS NOTE AND ANY
SUCH SHARES TO HAVE AGREED TO ANY SUCH AMENDMENT OR SUPPLEMENT.]

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

         THE SECURITIES EVIDENCED BY THIS GLOBAL SECURITY AND ANY COMMON STOCK
ISSUABLE UPON THE CONVERSION OF THE SECURITIES HAVE NOT BEEN REGISTERED UNDER
THE U.S. SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND MAY NOT
BE SOLD OR OTHERWISE TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR AN
APPLICABLE EXEMPTION THEREFROM. EACH PURCHASER OF ANY BENEFICIAL INTEREST IN THE
SECURITIES IS HEREBY NOTIFIED THAT THE SELLER OF SUCH BENEFICIAL INTEREST IN THE
SECURITIES MAY BE RELYING ON THE EXEMPTION FROM THE PROVISIONS OF SECTION 5 OF
THE SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER.

         EACH BENEFICIAL OWNER OF AN INTEREST IN ANY OF THE SECURITIES EVIDENCED
BY THIS GLOBAL SECURITY (INCLUDING ANY PARTICIPANT IN THE DEPOSITARY HOLDING THE
GLOBAL SECURITY THAT IS SHOWN AS HOLDING SUCH AN INTEREST ON THE RECORDS OF SUCH
DEPOSITARY AND EACH BENEFICIAL OWNER THAT HOLDS THROUGH ANY SUCH PARTICIPANT)
AGREES FOR THE BENEFIT OF CELL THERAPEUTICS, INC. (THE "COMPANY") THAT (A) ANY
BENEFICIAL INTEREST IN THE SECURITIES AND ANY SHARES OF COMMON STOCK ISSUABLE
UPON THEIR CONVERSION MAY BE OFFERED, SOLD, PLEDGED OR OTHERWISE TRANSFERRED
ONLY (A)(1) TO A PERSON WHO THE TRANSFEROR REASONABLY BELIEVES IS A QUALIFIED
INSTITUTIONAL BUYER WITHIN THE MEANING OF RULE 144A UNDER THE SECURITIES ACT
ACQUIRING FOR ITS OWN ACCOUNT OR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER
IN A TRANSACTION MEETING THE REQUIREMENTS OF RULE 144A, (2) PURSUANT TO AN
EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT PROVIDED BY RULE 144
THEREUNDER (IF AVAILABLE), (3) TO AN INSTITUTIONAL INVESTOR THAT IS AN
ACCREDITED INVESTOR WITHIN THE MEANING OF RULE 501(A)(1), (2), (3) OR (7) OF
REGULATION D UNDER THE SECURITIES ACT THAT PRIOR TO SUCH TRANSFER PROVIDES TO
THE TRUSTEE FOR THE NOTES A SIGNED LETTER CONTAINING CERTAIN REPRESENTATIONS AND
AGREEMENTS RELATING TO THE RESTRICTIONS ON TRANSFER OF THE NOTES (THE FORM OF
THE LETTER CAN BE OBTAINED FROM THE TRUSTEE OF THE NOTES), (4) PURSUANT TO
ANOTHER EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT (IF AVAILABLE) (AND
BASED UPON AN OPINION OF COUNSEL ACCEPTABLE TO CELL THERAPEUTICS, INC.) OR (5)
PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT, AND
(B) IN ACCORDANCE WITH ALL APPLICABLE SECURITIES LAWS OF THE STATES OF THE
UNITED STATES AND OTHER JURISDICTIONS AND THAT (B) THE BENEFICIAL OWNER WILL,
AND EACH SUBSEQUENT BENEFICIAL OWNER OF AN

                                      A-2
<PAGE>

INTEREST IN ANY OF THE SECURITIES EVIDENCED BY THIS GLOBAL SECURITY OR ANY
COMMON STOCK ISSUABLE UPON CONVERSION THEREOF IS REQUIRED TO, NOTIFY ANY
PURCHASER OF ANY BENEFICIAL INTEREST IN THE SECURITIES OR SUCH COMMON STOCK
ISSUABLE UPON ITS CONVERSION FROM IT OF THE RESALE RESTRICTIONS REFERRED TO IN
(A) ABOVE.

     THIS SECURITY, ANY SHARES OF COMMON STOCK ISSUABLE UPON ITS CONVERSION AND
ANY RELATED DOCUMENTATION MAY BE AMENDED OR SUPPLEMENTED FROM TIME TO TIME TO
MODIFY THE RESTRICTIONS ON RESALES AND OTHER TRANSFERS OF THIS NOTE AND ANY SUCH
SHARES TO REFLECT ANY CHANGE IN APPLICABLE LAW OR REGULATION (OR THE
INTERPRETATION THEREOF) OR IN PRACTICES RELATING TO THE RESALE OR TRANSFER OF
RESTRICTED SECURITIES GENERALLY. THE HOLDER OF THIS NOTE AND SUCH SHARES SHALL
BE DEEMED BY THE ACCEPTANCE OF THIS NOTE AND ANY SUCH SHARES TO HAVE AGREED TO
ANY SUCH AMENDMENT OR SUPPLEMENT.]

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

     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.]

                                      A-3
<PAGE>

     CELL THERAPEUTICS, INC.

     5.75% CONVERTIBLE SUBORDINATED NOTE DUE JUNE 15, 2008


No. ____________  U.S.$_____


CUSIP No. 150934 AA 5


     Cell Therapeutics, Inc., a corporation duly organized and existing under
the laws of the State of Washington (herein called the "Company," which term
includes any successor Person under the Indenture referred to on the reverse
hereof), for value received, hereby promises to pay to Cede & Co., or registered
assigns, the principal sum of _____________ United States Dollars (U.S.$ _____)
[if this Security is a Global Security, then insert -- (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 $150,000,000 in the aggregate at any time, unless
the Initial Purchasers exercise their over-allotment rights, in which case the
principal amount of the Outstanding Securities shall not exceed U.S.
$180,000,000) by adjustments made on the records of the Trustee hereinafter
referred to in accordance with the Indenture)] on June 15, 2008, unless redeemed
or repurchased on an earlier date, and to pay interest thereon, from June 13,
2001, or from the most recent Interest Payment Date (as defined below) to which
interest has been paid or duly provided for, semiannually in arrears on June 15
and December 15 in each year (each, an "Interest Payment Date"), commencing
December 15, 2001, at the rate of 5.75% per annum, until the principal hereof is
due, and at the rate then in effect 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
June 1 and December 1 (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 of Registered Securities not
less than ten days prior to such Special Record Date, or be paid at any time in
any other lawful manner not inconsistent with the requirements of any securities
exchange on which the Securities may be 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 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 coin or currency 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 Registered Securities in excess of
U.S.$2,000,000 and only if such Holder shall have

                                      A-4
<PAGE>

furnished wire instructions in writing to the Trustee no later than 15 days
prior to the relevant payment date) maintained by the payee. 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 Registered 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.

     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.

     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.

                                      A-5
<PAGE>

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

                                    CELL THERAPEUTICS, INC.


                                    By:___________________________________
                                       Name:
                                       Title:
Attest:



_______________________________
Name:


Dated:  June 13, 2001

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

STATE STREET BANK AND TRUST COMPANY OF CALIFORNIA, N.A.,
as Trustee



By:  ______________________________
     Authorized Signatory

                                      A-6
<PAGE>

                               [FORM OF REVERSE]

     This Security is one of a duly authorized issue of securities of the
Company designated as its "5.75% Convertible Subordinated Notes due June 15,
2008" (herein called the "Securities"), limited in aggregate principal amount to
U.S.$150,000,000 (U.S.$180,000,000 if the over-allotment is fully exercised),
issued and to be issued under an Indenture, dated as of June 13, 2001 (herein
called the "Indenture"), between the Company and State Street Bank and Trust
Company of California, N.A., a national banking association, as Trustee (herein
called the "Trustee," which term includes any successor trustee under the
Indenture), 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 set forth therein, Registered
Securities are exchangeable for a like aggregate principal amount of Registered
Securities of any authorized denominations as requested by the Holder
surrendering the same upon surrender of the Registered Security or Registered
Securities to be exchanged at the Corporate Trust Office. The Trustee upon such
surrender by the Holder will issue the new Registered Securities in the
requested denominations.

     No sinking fund is provided for the Securities.

     The Securities are subject to redemption at the option of the Company at
any time on or after June 21, 2004, 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
following Redemption Prices (expressed as percentages of the principal amount)
for the twelve-month period beginning on June 15 of the following years (June 21
through June 14 in the case of the first of such periods):

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

2004...........................................................   103.286%
2005...........................................................   102.464%
2006...........................................................   101.643%
2007...........................................................   100.821%

and thereafter at a Redemption Price equal to 100% of the principal amount,
together, in each case, with accrued interest to, but excluding 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.

     The Securities are subject to redemption at the option of the Company at
any time before June 21, 2004 ("Provisional Redemption"), in whole or in part,
upon not less than 30 nor more

                                      A-7
<PAGE>

than 60 days' notice to the Holders prior to the Redemption Date at a Redemption
Price equal to 100% of the principal amount, together, in each case, with
accrued interest to, but excluding, the Redemption Date, if (a) the closing
price of the Company's Common Stock has exceeded 150% of the Conversion Price
then in effect for at least 20 trading days within a period of 30 consecutive
trading days ending on the trading day before the date of mailing of the notice
of the Provisional Redemption, and (b) the Shelf Registration Statement is
effective and available for use and is expected to remain effective and
available for use for the 30 days following the Redemption Date, unless
registration is no longer required. Upon any Provisional Redemption, the Company
will pay to the Holders cash or Common Stock, or in a combination of cash and
Common Stock, with respect to the Securities called for Provisional Redemption,
and previously converted after the notice of Provisional Redemption and before
to the date of the Provisional Redemption, in an amount equal to $172.50 per
$1,000 principal amount of the Securities, less the amount of any interest paid
on the Securities before the date of the Provisional Redemption. For purposes of
any such payment in Common Stock, the value of such Common Stock will be based
upon the highest closing price of shares of the Common Stock for the 20 trading
days referred to above.

     In the event of a redemption of the Securities, the Company will not be
required (a) to register the transfer or exchange of Registered 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 (it being understood
that the Company will not be required to identify the serial numbers of
Outstanding Securities if all such Securities are called for redemption) or (b)
to register the transfer or exchange of any Registered Security, or portion
thereof, called for redemption.

     Notice to the Holders will be given not less than 30 nor more than 60 days
prior to the Redemption Date as provided in the Indenture.

     In any case where the due date for the payment of the principal of,
premium, if any, Liquidated Damages, if any, or interest on any Security or the
last day on which a Holder of a Security has a right to convert his Security
shall be, at any Place of Payment or Place of Conversion, as the case may be, a
day on which banking institutions at such Place of Payment or Place of
Conversion are authorized or obligated by law or executive order to close, then
payment of principal, premium, if any, Liquidated Damages, if any, or interest
or delivery for conversion of such Security 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, 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 following the
original issue date of the Securities

                                      A-8
<PAGE>

and on or before the close of business on June 15, 2008, 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 U.S.$1,000 or any integral multiple of
U.S.$1,000 in excess thereof) into fully paid and nonassessable shares of Common
Stock of the Company at an initial Conversion Rate of 29.4118 (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 has been called for redemption on a Redemption Date or
is repurchasable on a Repurchase Date, with the consequence that the conversion
right of such Security would terminate between such Regular Record Date and the
close of business on such Interest Payment Date), 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, 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 (each a "Conversion
Agent"), provided, further, that in case surrender of this Security for
conversion 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 and if this Security or portion hereof
has been called for redemption on a Redemption Date or is repurchasable on a
Repurchase Date, with the consequence that the conversion right of such Security
would terminate between such Regular Record Date and the close of business on
such Interest Payment Date, then the Holder of this Security 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 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 or

                                      A-9
<PAGE>

rights or warrants, as provided in the Indenture) into which this Security is
convertible and such delivery will be 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 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 of Securities, so that this
Security, if then Outstanding, will be convertible thereafter, during the period
this Security shall be convertible as specified above, only into the kind and
amount of securities, cash and other property receivable upon 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.

     Subject to certain limitations in the Indenture, at any time when the
Company is not subject to Section 13 or 15(d) of the United States Securities
Exchange Act of 1934, as amended, upon the request of a Holder of a Security or
the holder of shares of Common Stock issued upon conversion thereof, the Company
will promptly furnish or cause to be furnished Rule 144A Information (as defined
below) to such Holder of Securities or such holder of shares of Common Stock
issued upon conversion of Securities, or to a prospective purchaser of any such
security designated by any such Holder or holder, as the case may be, to the
extent required to permit compliance by such Holder or holder with Rule 144A
under the Securities Act of 1933, as amended (the "Securities Act"), in
connection with the resale of any such security. "Rule 144A Information" shall
be such information as is specified pursuant to Rule 144A(d) (4) under the
Securities Act (or any successor provision thereto).

     The Holder of this Security [if this Security is a Global Security, then
insert (including any Person that has a beneficial interest in this Security)]
and the Common Stock issuable upon conversion hereof is entitled to the benefits
of a Registration Rights Agreement, dated as of June 13, 2001 (the "Registration
Rights Agreement"), executed by the Company. Pursuant to the Registration Rights
Agreement, the Company has agreed for the benefit of the Holders from time to
time of Registered Securities and the Common Stock issuable upon conversion
thereof, in each case, that are Registrable Securities, at the Company's
expense, (a) to file on or before 90 days after the first date of original
issuance of the Securities, a shelf registration statement (the "Shelf
Registration Statement") with the Commission with respect to resales of the
Registrable Securities, (b) thereafter to use its reasonable efforts to cause
such Shelf Registration Statement

                                     A-10
<PAGE>

to be declared effective by the Commission on or before 180 days after the first
date of original issuance of the Securities, subject to the Company's right to
postpone having the Shelf Registration Statement declared effective for an
additional 60 days in limited circumstances described in the Registration
Rights Agreement, and (c) to use all reasonable efforts to maintain such Shelf
Registration Statement continuously effective under the Securities Act until the
earlier of (1) the sale under the Shelf Registration Statement of all the
Registrable Securities registered thereunder and (2) the expiration of the
holding period applicable to such Registrable Securities held by persons that
are not affiliates of the Company under Rule 144(k) under the Securities Act or
any successor previously subject to specific permitted exceptions. The Company
is required to pay Liquidated Damages to holders of Registrable Securities for
failure to comply with the foregoing registration obligations, all as more fully
set forth in the Registration Rights Agreement.

     Whenever in this Security there is a reference, in any context, to the
payment of the principal of, premium, if any, or interest on, or in respect of,
any Security such mention shall be deemed to include mention of the payment of
Liquidated Damages payable as described in the Registration Rights Agreement to
the extent that, in such context, Liquidated Damages are, were or would be
payable in respect of this Security pursuant to the Registration Rights
Agreement, and an express mention of the payment of Liquidated Damages (if
applicable) in any provisions of this Security shall not be construed as
excluding Liquidated Damages in those provisions of this Security where such
express mention is not made. If the Holder of this Security [if this Security is
a Global Security, then insert (including any Person that has a beneficial
interest in this Security)] elects to sell this Security pursuant to the Shelf
Registration Statement then, by its acceptance hereof, such Holder of this
Security agrees to be bound by the terms of the Registration Rights Agreement
relating to the Registrable Securities which are the subject of such election.

     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 U.S.$1,000 or any greater integral
multiple of U.S.$1,000) for cash at a Repurchase Price equal to 100% of the
principal amount thereof plus interest accrued to, but excluding, the Repurchase
Date. At the option of the Company, the Repurchase Price may be paid in cash or,
subject to the conditions provided in the Indenture, by delivery of shares of
Common Stock or in a combination of cash and 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 95% 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

                                     A-11
<PAGE>

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
paragraph below concerning the consequences of an Event of Default, such
reference shall be deemed to include reference to the Repurchase Price only to
the extent the Repurchase Price is payable in cash.

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

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

     [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 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 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 in cash or Cash Equivalents 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

                                     A-12
<PAGE>

the written consent of the Holders of a majority in principal amount of the
Securities at the time Outstanding. The Indenture also contains provisions
permitting the Holders of 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 herefor 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, the Trustee
shall have failed to institute any such proceeding for 60 days after receipt of
such notice, request and offer of indemnity, and the Trustee has not received
any direction inconsistent with such written request from the Holders of a
majority of the aggregate principal amount of the Outstanding Securities during
such 60 day period. 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, Liquidated Damages, 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.

         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,
Liquidated Damages, 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.

         As provided in the Indenture and subject to certain limitations therein
set forth, the transfer of Registered Securities is registrable on the Security
Register upon surrender of a Registered 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, 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 Registered 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-13
<PAGE>

a sum sufficient to recover any tax or other governmental charge payable in
connection therewith.

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

         Interest on the Securities shall be computed on the basis of a 360-day
year of twelve 30-day months. 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, including, without limitation, Section 5-1401 of the New York
General Obligations Law.

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

                                     A-14
<PAGE>

                                                                       EXHIBIT B


                   ELECTION OF HOLDER TO REQUIRE REPURCHASE


         1. Pursuant to Section 12.1 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 equal to 100% of the principal amount
to be repurchased (as set forth below), plus interest accrued to the Repurchase
Date or, at the Company's election, Common Stock, valued as set forth in the
Indenture.


                                    Dated:__________


                                    ________________
                                    Signature

                                    Signature Guaranteed


                                    ________________


Principal amount to be repurchased:


____________________________________
(must be equal to U.S.$1,000 or any
greater integral multiple of U.S.$1,000):

Remaining principal amount following such repurchase:




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.

                                      B-1
<PAGE>

                                                                       EXHIBIT C

                               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) 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, the undersigned will pay all transfer taxes payable with
respect thereto. Any amount required to be paid by the undersigned on account of
interest accompanies this Security.

Dated: _________________                ________________________________________
                                                       Signature

If shares or Registered Securities      If only a portion of the Securities is
are to be registered in the name of a   to be converted, please indicate:
Person other than the Holder, please
print such Person's name and address:
                                        1. Principal amount to be converted:

_____________________________________      U.S.$_______________________
                                           (any integral multiple of U.S.
                                             $1,000)
_____________________________________
               Address
                                        2. Principal amount and denomination of
                                           Registered Securities representing
                                           unconverted principal amount to be
                                           issued:
_____________________________________
Social Security or other Taxpayer
Identification Number, if any
                                           Amount: U.S.$__________________

_____________________________________
       [Signature Guaranteed]

                                      C-1