<PAGE>
                                                                     Exhibit 4.1




================================================================================

================================================================================

                                 ANTIGENICS INC.

                                       and

                       HSBC BANK USA, NATIONAL ASSOCIATION

                                   as Trustee

                                   ----------

                                    INDENTURE

                          Dated as of January 25, 2005

                                   ----------

                          $50,000,000 Principal Amount

                     5.25% CONVERTIBLE SENIOR NOTES DUE 2025


================================================================================

================================================================================
<PAGE>
                              CROSS-REFERENCE TABLE

<TABLE>
<CAPTION>
  TIA                                                         Indenture
Section                                                        Section
-------                                                        -------
<S>                                                           <C>
310(a)(1)...............................................       7.10
    (a)(2)..............................................       7.10
    (a)(3)..............................................       N.A.
    (a)(4)..............................................       N.A.
    (a)(5)..............................................       7.10
    (b).................................................       7.08; 7.10; 11.02
    (c).................................................       N.A.
311(a)..................................................       7.11
    (b).................................................       7.11
    (c).................................................       N.A.
312(a)..................................................       2.05
    (b).................................................      11.03
    (c).................................................      11.03
313(a)..................................................       7.06
    (b)(1)..............................................       7.06
    (b)(2)..............................................       7.06
    (c).................................................       7.06; 11.02
    (d).................................................       7.06
314(a)..................................................       4.03
    (b).................................................       N.A.
    (c)(1)..............................................      11.04
    (c)(2)..............................................      11.04
    (c)(3)..............................................       N.A.
    (d).................................................       N.A.
    (e).................................................      11.05
    (f).................................................       N.A.
315(a)..................................................       7.01(B)
    (b).................................................       7.05; 11.02
    (c).................................................       7.01(A)
    (d).................................................       7.01(C)
    (e).................................................       6.11
316(a) (last sentence)..................................       2.09
    (a)(1)(A)...........................................       6.05
    (a)(1)(B)...........................................       6.04
    (a)(2)..............................................       N.A.
    (b).................................................       6.07
    (c).................................................       9.04
317(a)(1)...............................................       6.08
    (a)(2)..............................................       6.09
    (b).................................................       2.04
318(a)..................................................      11.01
</TABLE>




                                        I
<PAGE>
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                Page
                                                                                ----
<S>                                                                             <C>
I.    DEFINITIONS AND INCORPORATION BY REFERENCE                                   1

      1.01 Definitions......................................................       1
      1.02 Other Definitions................................................       5
      1.03 Incorporation by Reference of Trust Indenture Act................       7
      1.04 Rules of Construction............................................       7

II.   THE SECURITIES                                                               8

      2.01 Form and Dating..................................................       8
      2.02 Execution and Authentication.....................................       8
      2.03 Registrar, Paying Agent and Conversion Agent.....................       9
      2.04 Paying Agent to Hold Money in Trust..............................      10
      2.05 Securityholder Lists.............................................      10
      2.06 Transfer and Exchange............................................      10
      2.07 Replacement Securities...........................................      11
      2.08 Outstanding Securities...........................................      11
      2.09 Securities Held by the Company or an Affiliate...................      12
      2.10 Temporary Securities.............................................      12
      2.11 Cancellation.....................................................      13
      2.12 Defaulted Interest...............................................      13
      2.13 CUSIP Numbers....................................................      13
      2.14 Deposit of Moneys and Property...................................      13
      2.15 Book-Entry Provisions for Global Securities......................      14
      2.16 Special Transfer Provisions......................................      15
      2.17 Restrictive Legends..............................................      16
      2.18 Ranking..........................................................      16

III.  REDEMPTION AND REPURCHASE                                                   17

      3.01 Right of Redemption..............................................      17
      3.02 Notices to Trustee...............................................      17
      3.03 Selection of Securities to Be Redeemed...........................      17
      3.04 Notice of Redemption.............................................      18
      3.05 Effect of Notice of Redemption...................................      19
      3.06 Deposit of Redemption Price......................................      20
      3.07 Securities Redeemed in Part......................................      20
      3.08 Purchase of Securities at Option of the Holder...................      20
      3.09 Repurchase at Option of Holder Upon a Fundamental Change.........      24
      3.10 Conversion Arrangement on Call for Redemption....................      31
</TABLE>


                                       -i-
<PAGE>
<TABLE>
<S>                                                                             <C>
IV.   COVENANTS                                                                   32

      4.01 Payment of Securities............................................      32
      4.02 Maintenance of Office or Agency..................................      32
      4.03 Rule 144A Information and Annual Reports.........................      33
      4.04 Compliance Certificate...........................................      34
      4.05 Stay, Extension and Usury Laws...................................      34
      4.06 Corporate Existence..............................................      34
      4.07 Notice of Default................................................      34
      4.08 Further Instruments and Acts.....................................      34

V.    SUCCESSORS                                                                  35

      5.01 When Company May Merge, etc......................................      35
      5.02 Successor Substituted............................................      35

VI.   DEFAULTS AND REMEDIES                                                       36

      6.01 Events of Default................................................      36
      6.02 Acceleration.....................................................      37
      6.03 Other Remedies...................................................      38
      6.04 Waiver of Past Defaults..........................................      38
      6.05 Control by Majority..............................................      39
      6.06 Limitation on Suits..............................................      39
      6.07 Rights of Holders to Receive Payment.............................      39
      6.08 Collection Suit by Trustee.......................................      40
      6.09 Trustee May File Proofs of Claim.................................      40
      6.10 Priorities.......................................................      40
      6.11 Undertaking for Costs............................................      41

VII.  TRUSTEE                                                                     41

      7.01 Duties of Trustee................................................      41
      7.02 Rights of Trustee................................................      42
      7.03 Individual Rights of Trustee.....................................      43
      7.04 Trustee's Disclaimer.............................................      43
      7.05 Notice of Defaults...............................................      44
      7.06 Reports by Trustee to Holders....................................      44
      7.07 Compensation and Indemnity.......................................      44
      7.08 Replacement of Trustee...........................................      45
      7.09 Successor Trustee by Merger, etc.................................      46
      7.10 Eligibility; Disqualification....................................      46
      7.11 Preferential Collection of Claims Against Company................      46

VIII. DISCHARGE OF INDENTURE                                                      46

      8.01 Termination of the Obligations of the Company....................      46
      8.02 Application of Trust Money.......................................      47
</TABLE>


                                      -ii-
<PAGE>
<TABLE>
<S>                                                                             <C>
      8.03 Repayment to Company.............................................      47
      8.04 Reinstatement....................................................      47

IX.   AMENDMENTS                                                                  48

      9.01 Without Consent of Holders.......................................      48
      9.02 With Consent of Holders..........................................      48
      9.03 Compliance with Trust Indenture Act..............................      50
      9.04 Revocation and Effect of Consents................................      50
      9.05 Notation on or Exchange of Securities............................      51
      9.06 Trustee Protected................................................      51
      9.07 Effect of Supplemental Indentures................................      51

X.    CONVERSION                                                                  51

      10.01 Conversion Privilege; Restrictive Legends.......................      51
      10.02 Conversion Procedure............................................      52
      10.03 Fractional Shares...............................................      53
      10.04 Taxes on Conversion.............................................      53
      10.05 Company to Provide Stock........................................      54
      10.06 Adjustment of Conversion Rate...................................      54
      10.07 No Adjustment...................................................      59
      10.08 Other Adjustments...............................................      60
      10.09 Adjustments for Tax Purposes....................................      60
      10.10 Notice of Adjustment............................................      60
      10.11 Notice of Certain Transactions..................................      61
      10.12 Effect of Reclassifications, Consolidations, Mergers, Binding
              Share Exchanges or Sales on Conversion Privilege..............      61
      10.13 Trustee's Disclaimer............................................      62
      10.14 Rights Distributions Pursuant to Stockholders' Rights Plans.....      63
      10.15 Increased Conversion Rate Applicable to Certain Notes
              Surrendered in Connection With Make-Whole Fundamental Changes.      63

XI.   MISCELLANEOUS                                                               68

      11.01 Trust Indenture Act Controls....................................      68
      11.02 Notices.........................................................      68
      11.03 Communication by Holders with Other Holders.....................      69
      11.04 Certificate and Opinion as to Conditions Precedent..............      69
      11.05 Statements Required in Certificate or Opinion...................      70
      11.06 Rules by Trustee and Agents.....................................      70
      11.07 Legal Holidays..................................................      70
      11.08 Duplicate Originals.............................................      70
      11.09 Governing Law...................................................      71
      11.10 No Adverse Interpretation of Other Agreements...................      71
      11.11 Successors......................................................      71
      11.12 Separability....................................................      71
</TABLE>


                                      -iii-
<PAGE>
<TABLE>
<S>                                                                             <C>
      11.13 Table of Contents, Headings, etc................................      71
      11.14 Calculations in Respect of the Securities.......................      71
      11.15 No Personal Liability of Directors, Employees or Stockholders...      71
</TABLE>


Exhibit A   -     Form of Global Security

Exhibit B-1 -     Form of Private Placement Legend

Exhibit B-2 -     Form of Legend for Global Security

Exhibit C   -     Form of Notice of Transfer Pursuant to Registration Statement

Exhibit D   -     Form of Opinion of Counsel in Connection with Registration of
                  Securities




                                      -iv-
<PAGE>
      INDENTURE, dated as of January 25, 2005, between Antigenics Inc., a
Delaware corporation (the "COMPANY"), and HSBC Bank USA, National Association,
as trustee (the "TRUSTEE").

      Each party agrees as follows for the benefit of the other party and for
the equal and ratable benefit of the Holders of the Company's 5.25% Convertible
Senior Notes due 2025 (the "SECURITIES").

                  I. DEFINITIONS AND INCORPORATION BY REFERENCE

1.01  DEFINITIONS.

      The term "ADDITIONAL INTEREST" has the meaning ascribed to it in the
Registration Rights Agreement.

      "AFFILIATE" means any person directly or indirectly controlling or
controlled by or under direct or indirect common control with the Company. For
this purpose, "control" shall mean the power to direct the management and
policies of a person through the ownership of securities, by contract or
otherwise.

      "BOARD OF DIRECTORS" means the Board of Directors of the Company or any
committee thereof authorized to act for it hereunder.

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

      "CAPITAL STOCK" of any Person means any and all shares, interests,
participations or other equivalents (however designated) of capital stock of
such Person and all warrants or options to acquire such capital stock.

      "CLOSING SALE PRICE" means the price of a share of Common Stock on the
relevant date, determined (a) on the basis of the closing per share sale price
(or if no closing sale price is reported, the average of the bid and ask prices
or, if more than one in either case, the average of the average bid and the
average ask prices) on such date on the U.S. principal national securities
exchange on which the Common Stock is listed; or (b) if the Common Stock is not
listed on a U.S. national securities exchange, as reported by the National
Association of Securities Dealers Automated Quotation System; or (c) if not so
quoted, as reported by National Quotation Bureau, Incorporated or a similar
organization. In the absence of a quotation, the Closing Sale Price shall be
such price as the Company shall reasonably determine on the basis of such
quotations as most accurately reflecting the price that a fully informed buyer,
acting on his own accord, would pay to a fully informed seller, acting on his
own accord in an arms-length transaction, for a share of such Common Stock.


                                      -1-
<PAGE>
      "COMMON STOCK" means the common stock, $0.01 par value per share, of the
Company, or such other Capital Stock of the Company into which the Company's
common stock is reclassified or changed.

      "COMPANY" means the party named as such above until a successor replaces
it pursuant to the applicable provision hereof and thereafter means the
successor. The foregoing sentence shall likewise apply to any such successor or
subsequent successor.

      Each of "COMPANY ORDER" and "COMPANY REQUEST" means a written request or
order signed on behalf of the Company by its Chairman of the Board, its Chief
Executive Officer, its President, its Chief Operating Officer, its Chief
Financial Officer, any Executive Vice President or any Senior Vice President and
by its Treasurer or an Assistant Treasurer or its Secretary or an Assistant
Secretary, and delivered to the Trustee.

      "CONVERSION RATE" means the number of shares of Common Stock issuable upon
conversion of a Security per $1,000 principal amount, which Conversion Rate
shall initially be 92.9023 shares of Common Stock per $1,000 principal amount of
Securities, subject to adjustment as provided in Article X.

      "CONVERSION PRICE" means, as of any date of determination, the dollar
amount derived by dividing one thousand dollars ($1,000) by the Conversion Rate
in effect on such date.

      "CORPORATE TRUST OFFICE OF THE TRUSTEE" shall be at the address of the
Trustee specified in Section 11.02 or such other address as the Trustee may give
notice of to the Company and the Holders.

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

      "DEPOSITARY" means The Depository Trust Company, its nominees and
successors.

      "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended, and
the rules and regulations of the SEC thereunder.

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

      "INDEBTEDNESS" of a person means the principal of, premium, if any, and
interest on, and all other obligations in respect of (a) all indebtedness of
such person for borrowed money (including all indebtedness evidenced by notes,
bonds, debentures or other securities), (b) all obligations (other than trade
payables) incurred by such person in the acquisition (whether by way of
purchase, merger, consolidation or otherwise and whether by such person or
another person) of any business, real property or other assets, (c) all
reimbursement obligations of such person with respect to letters of credit,
bankers' acceptances or similar facilities issued for the account of such
person, (d) all capital lease obligations of such person, (e) all net
obligations of such person under interest rate swap, currency exchange or
similar agreements of such person, (f) all obligations and other liabilities,
contingent or otherwise, under any lease or related document, including a
purchase agreement, conditional sale or other title retention agreement, in

                                      -2-
<PAGE>
connection with the lease of real property or improvements thereon (or any
personal property included as part of any such lease) which provides that such
person is contractually obligated to purchase or cause a third party to purchase
the leased property or pay an agreed-upon residual value of the leased property,
including such person's obligations under such lease or related document to
purchase or cause a third party to purchase such leased property or pay an
agreed-upon residual value of the leased property to the lessor, (g) guarantees
by such person of indebtedness described in clauses (a) through (f) of another
person, and (h) all renewals, extensions, refundings, deferrals, restructurings,
amendments and modifications of any indebtedness, obligation, guarantee or
liability of the kind described in clauses (a) through (g).

      "INDENTURE" means this Indenture as amended or supplemented from time to
time.

      "INITIAL PURCHASERS" means UBS Securities LLC, Moors & Cabot, Inc. and
Brimberg & Co.

      "ISSUE DATE" means January 25, 2005.

      "MAKE-WHOLE FUNDAMENTAL CHANGE" means an Acquisition of Voting Control, a
Qualifying Asset Sale or a Qualifying Business Combination that occurs before
February 1, 2012, provided at least 10% of the consideration (excluding cash
payments for fractional shares or pursuant to statutory appraisal rights) for
the Common Stock in such Acquisition of Voting Control, Qualifying Asset Sale or
Qualifying Business Combination consists of any combination of cash or
securities (or other property) that are neither (A) traded on a U.S. national
securities exchange or quoted on the Nasdaq National Market nor (B) scheduled to
be so traded or quoted immediately after such Acquisition of Voting Control,
Qualifying Asset Sale or Qualifying Business Combination.

      "MATURITY DATE" means February 1, 2025.

      "OFFICER" means the Chairman of the Board, the Chief Executive Officer,
the President, the Chief Operating Officer, the Chief Financial Officer, any
Executive Vice President or any Senior Vice President of the Company.

      "OFFICER'S CERTIFICATE" means a certificate signed by an Officer of the
Company.

      "OPINION OF COUNSEL" means a written opinion from legal counsel who may be
an employee of or counsel for the Company, or other counsel reasonably
acceptable to the Trustee.

      "OPTION" means the Initial Purchasers' option to acquire up to $10,000,000
aggregate principal amount of additional Securities ("ADDITIONAL SECURITIES") as
provided for in the Purchase Agreement.

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

      "PUBLIC ACQUIRER FUNDAMENTAL CHANGE" shall mean an acquisition of the
Company pursuant to an Acquisition of Voting Control, a Qualifying Asset Sale or
a Qualifying Business

                                      -3-
<PAGE>
Combination, provided the acquirer in such Acquisition of Voting Control,
Qualifying Asset Sale or Qualifying Business Combination (or any entity that is
a direct or indirect wholly owned "subsidiary" (as defined in Rule 405 under the
Securities Act) of such acquirer) has a class of common stock ("PUBLIC ACQUIRER
COMMON STOCK") that either (A) is traded on a U.S. national securities exchange
or quoted on the Nasdaq National Market or (B) will be so traded or quoted when
issued or exchanged in connection with such Acquisition of Voting Control,
Qualifying Asset Sale or Qualifying Business Combination.

      "PURCHASE AGREEMENT" means the Purchase Agreement dated January 20, 2005
between the Company and the Initial Purchasers.

      "PURCHASE NOTICE" means a Purchase Notice in the form set forth in the
Securities.

      "QIB" means a "qualified institutional buyer" within the meaning of Rule
144A promulgated under the Securities Act.

      "REDEMPTION DATE" means the date specified for Redemption of the
Securities in accordance with the terms of the Securities and this Indenture.

      "REDEMPTION PRICE" means, with respect to a Security to be redeemed by the
Company in accordance with Article III, one hundred percent (100%) of the
outstanding principal amount of such Security to be redeemed.

      "REGISTRATION RIGHTS AGREEMENT" means the Registration Rights Agreement
dated as of the date hereof between the Company and the Initial Purchasers.

      "RESPONSIBLE OFFICER" shall mean, when used with respect to the Trustee,
any officer within the corporate trust department of the Trustee, including any
vice president, assistant vice president, assistant secretary, assistant
treasurer, trust officer or any other officer of the Trustee who customarily
performs functions similar to those performed by the Persons who at the time
shall be such officers, respectively, or to whom any corporate trust matter is
referred because of such person's knowledge of and familiarity with the
particular subject and who shall have direct responsibility for the
administration of this Indenture.

      "RESTRICTED SECURITY" means a Security that constitutes a "restricted
security" within the meaning of Rule 144(a)(3) under the Securities Act;
provided, however, that the Trustee shall be entitled to request and
conclusively rely on an Opinion of Counsel with respect to whether any Security
constitutes a Restricted Security.

      "RULE 144A" means Rule 144A promulgated under the Securities Act, as such
rule may be amended and in effect from time to time.

      "SEC" means the Securities and Exchange Commission.

      "SECURITIES" means the 5.25% Convertible Senior Notes due 2025 issued by
the Company pursuant to this Indenture.

                                      -4-
<PAGE>
      "SECURITIES ACT" means the Securities Act of 1933, as amended, and the
rules and regulations of the SEC thereunder.

      "SECURITY AGENT" means any Registrar, Paying Agent, Conversion Agent or
co-Registrar or co-agent.

      "SIGNIFICANT SUBSIDIARY" with respect to any person means any subsidiary
of such person that constitutes a "significant subsidiary" within the meaning of
Rule 1-02(w) of Regulation S-X promulgated under the Securities Act, as such
regulation is in effect on the date of this Indenture.

      "SUBSIDIARY" means (i) a corporation a majority of whose Capital Stock
with voting power, under ordinary circumstances, to elect directors is at the
time, directly or indirectly, owned by the Company, by one or more subsidiaries
of the Company or by the Company and one or more of its subsidiaries or (ii) any
other person (other than a corporation), including, without limitation, a
partnership or joint venture, in which the Company, one or more of its
subsidiaries, or the Company and one or more of its subsidiaries, directly or
indirectly, at the date of determination thereof, own at least a majority
ownership interest entitled to vote in the election of directors, managers or
trustees (or members of any other equivalent governing body) thereof.

      "TIA" means the Trust Indenture Act of 1939 (15 U.S. Code Sections
77aaa-77bbbb) as amended and in effect from time to time.

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

      "TRUSTEE" means the party named as such in this Indenture until a
successor replaces it in accordance with the provisions hereof and thereafter
means the successor.

      "VOTING STOCK" of any Person means the total voting power of all classes
of the Capital Stock of such Person entitled to vote generally in the election
of directors of such Person.

1.02  OTHER DEFINITIONS.

<TABLE>
<CAPTION>
             Term                                           Defined in Section
             ----                                           ------------------
<S>                                                         <C>
       "ACQUIRER STOCK CONVERSION RIGHT ADJUSTMENT" .....          10.15
       "ACQUISITION OF VOTING CONTROL" ..................           3.09
       "ADDITIONAL SECURITIES" ..........................           1.01
       "AGGREGATE AMOUNT" ...............................          10.06
       "APPLICABLE INCREASE" ............................          10.15
       "APPLICABLE PRICE" ...............................          10.15
</TABLE>


                                      -5-
<PAGE>
<TABLE>
<S>                                                         <C>
       "BANKRUPTCY LAW" .................................           6.01
       "BUSINESS DAY" ...................................          11.07
       "CHANGE IN CONTROL" ..............................           3.09
       "CONVERSION AGENT" ...............................           2.03
       "CONVERSION DATE" ................................          10.02
       "CONVERSION SHARES" ..............................          10.06
       "CUSTODIAN" ......................................           6.01
       "DETERMINATION DATE" .............................          10.06
       "DISTRIBUTION DATE" ..............................          10.06
       "EFFECTIVE DATE" .................................          10.15
       "EVENT OF DEFAULT" ...............................           6.01
       "EX DATE" ........................................          10.06
       "EXPIRATION DATE" ................................          10.06
       "EXPIRATION TIME" ................................          10.06
       "FUNDAMENTAL CHANGE" .............................           3.09
       "FUNDAMENTAL CHANGE NOTICE" ......................           3.09
       "FUNDAMENTAL CHANGE REPURCHASE DATE" .............           3.09
       "FUNDAMENTAL CHANGE REPURCHASE PRICE" ............           3.09
       "FUNDAMENTAL CHANGE REPURCHASE RIGHT" ............           3.09
       "GLOBAL SECURITY" ................................           2.01
       "LEGAL HOLIDAY" ..................................          11.07
       "MAKE-WHOLE CONSIDERATION" .......................          10.15
       "MAKE-WHOLE CONVERSION RATE ADJUSTMENT" ..........          10.15
       "NOTICE OF DEFAULT" ..............................           6.01
       "OPTION PURCHASE DATE" ...........................           3.08
       "OPTION PURCHASE NOTICE" .........................           3.08
       "OPTION PURCHASE PRICE" ..........................           3.08
       "PARTICIPANTS" ...................................           2.15
       "PAYING AGENT" ...................................           2.03
       "PERMITTED STRATEGIC TRANSACTION" ................           3.09
       "PHYSICAL SECURITIES" ............................           2.01
       "PRIVATE PLACEMENT LEGEND" .......................           2.17
       "PUBLIC ACQUIRER COMMON STOCK" ...................           1.01
       "PURCHASE AT HOLDER'S OPTION" ....................           3.01
       "PURCHASED SHARES" ...............................          10.06
       "QUALIFYING ASSET SALE" ..........................           3.09
       "QUALIFYING BUSINESS COMBINATION" ................           3.09
       "REDEMPTION" .....................................           3.01
       "REFERENCE PRICE" ................................          10.15
       "REGISTRAR" ......................................           2.03
       "REPURCHASE UPON FUNDAMENTAL CHANGE" .............           3.01
       "RESALE RESTRICTION TERMINATION DATE" ............           2.17
       "RIGHTS" .........................................          10.06
       "SHELF REGISTRATION STATEMENT" ...................           2.16
       "TERMINATION OF TRADING" .........................           3.09
       "UNDERLYING SHARES" ..............................          10.06
</TABLE>


                                      -6-
<PAGE>
1.03  INCORPORATION BY REFERENCE OF TRUST INDENTURE ACT.

      Whenever this Indenture refers to a provision of the TIA, the provision is
incorporated by reference in and made a part of this Indenture.

      The following TIA terms used in this Indenture have the following
meanings:

      "COMMISSION" means the SEC;

      "INDENTURE SECURITIES" means the Securities;

      "INDENTURE SECURITY HOLDER" means a Securityholder or a Holder;

      "INDENTURE TO BE QUALIFIED" means this Indenture;

      "INDENTURE TRUSTEE" or "INSTITUTIONAL TRUSTEE" means the Trustee; and

      "OBLIGOR" on the indenture securities means the Company or any successor
      thereof.

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

1.04  RULES OF CONSTRUCTION.

      Unless the context otherwise requires:

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

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

            (iii) "or" is not exclusive;

            (iv) words in the singular include the plural and in the plural
      include the singular;

            (v) provisions apply to successive events and transactions;

            (vi) "close of business" on a date shall refer to 5:00 pm, New York
      City time, on such date;

            (vii) the term "INTEREST" includes additional interest, unless the
      context otherwise requires or unless the terms of the Registration Rights
      Agreement provide otherwise;

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


                                      -7-
<PAGE>
            (ix) references to currency shall mean the lawful currency of the
      United States of America, unless the context requires otherwise.

                               II. THE SECURITIES

2.01  FORM AND DATING.

      The Securities and the Trustee's certificate of authentication shall be
substantially in the form set forth in EXHIBIT A, which is incorporated in and
forms a part of this Indenture. The Securities may have notations, legends or
endorsements required by law, stock exchange rule or usage, provided such
notations, legends or endorsements are in form reasonably acceptable to the
Company. The Company shall provide any such notations, legends or endorsements
to the Trustee in writing. Each Security shall be dated the date of its
authentication.

      Securities offered and sold in reliance on Rule 144A shall be issued
initially in the form of one or more Global Securities, in registered form,
substantially in the form set forth in EXHIBIT A (the "GLOBAL SECURITY"),
deposited with the Trustee, as custodian for the Depositary, and registered in
the name of the Depositary or a nominee thereof, duly executed by the Company
and authenticated by the Trustee as hereinafter provided and bearing the legends
set forth in EXHIBITS B-1 and B-2. The aggregate principal amount of the Global
Security may from time to time be increased or decreased by adjustments made on
the records of the Trustee, as custodian for the Depositary, as hereinafter
provided; provided, that in no event shall the aggregate principal amount of the
Global Security or Securities exceed $50,000,000 (or $60,000,000 if the Initial
Purchasers elect to purchase all of the Additional Securities pursuant to the
Option).

      Securities issued in exchange for interests in a Global Security pursuant
to Section 2.15 may be issued in the form of permanent certificated Securities
in registered form in substantially the form set forth in EXHIBIT A (the
"PHYSICAL SECURITIES") and, if applicable, bearing any legends required by
Section 2.17.

2.02  EXECUTION AND AUTHENTICATION.

      One duly authorized Officer shall sign the Securities for the Company by
manual or facsimile signature.

      A Security's validity shall not be affected by the failure of an Officer
whose signature is on such Security to hold, at the time the Security is
authenticated, the same office at the Company.

      A Security shall not be valid until authenticated by the manual signature
of the Trustee. The signature shall be conclusive evidence that the Security has
been authenticated under this Indenture.

      Upon a written order of the Company signed by one Officer of the Company,
the Trustee shall authenticate Securities for original issue in the aggregate
principal amount of $50,000,000 and such additional principal amount, if any, as
shall be determined pursuant to the next sentence of this Section 2.02. Upon
receipt by the Trustee of an Officer's Certificate stating that the

                                      -8-
<PAGE>
Initial Purchasers have elected to purchase from the Company a specified
principal amount of Additional Securities, not to exceed $10,000,000, pursuant
to the Option, the Trustee shall authenticate and deliver such specified
principal amount of Additional Securities to or upon the written order of the
Company signed as provided in the immediately preceding sentence. Such Officer's
Certificate must be received by the Trustee not later than the proposed date for
delivering of such Additional Securities. The aggregate principal amount of
Securities outstanding at any time may not exceed $50,000,000 except as provided
in this Section 2.02.

      Upon a written order of the Company signed by one Officer of the Company,
the Trustee shall authenticate Securities not bearing the Private Placement
Legend to be issued to the transferee when sold pursuant to an effective
registration statement under the Securities Act as set forth in Section 2.16(B).

      The Trustee shall act as the initial authenticating agent. Thereafter, the
Trustee may appoint an authenticating agent reasonably acceptable to the Company
to authenticate Securities. An authenticating agent may authenticate Securities
whenever the Trustee may do so. Each reference in this Indenture to
authentication by the Trustee includes authentication by such authenticating
agent. An authenticating agent has the same rights as a Security Agent to deal
with the Company and its Affiliates.

      If a written order of the Company pursuant to this Section 2.02 has been,
or simultaneously is, delivered, any instructions by the Company to the Trustee
with respect to endorsement, delivery or redelivery of a Security issued in
global form shall be in writing but need not comply with Section 11.04 hereof
and need not be accompanied by an Opinion of Counsel.

      The Securities shall be issuable only in registered form without interest
coupons and only in denominations of $1,000 principal amount and any integral
multiple thereof.

2.03  REGISTRAR, PAYING AGENT AND CONVERSION AGENT.

      The Company shall maintain, or cause to be maintained, (i) an office or
agency in the Borough of Manhattan, The City of New York, where Securities may
be presented for registration of transfer or for exchange ("REGISTRAR"); (ii) an
office or agency in the Borough of Manhattan, The City of New York, where
Securities may be presented for payment ("PAYING AGENT"); and (iii) an office or
agency in the Borough of Manhattan, The City of New York, where Securities may
be presented for conversion ("CONVERSION AGENT"). The Registrar shall keep a
register of the Securities and of their transfer and exchange. The Company may
appoint or change one or more co-Registrars, one or more additional paying
agents and one or more additional conversion agents without notice and may act
in any such capacity on its own behalf. The term "REGISTRAR" includes any
co-Registrar; the term "PAYING AGENT" includes any additional paying agent; and
the term "CONVERSION AGENT" includes any additional conversion agent.

      The Company shall enter into an appropriate agency agreement with any
Security Agent not a party to this Indenture. The agreement shall implement the
provisions of this Indenture that relate to such Security Agent. The Company
shall notify the Trustee in writing of the name and

                                      -9-
<PAGE>
address of any Security Agent not a party to this Indenture. If the Company
fails to maintain a Registrar, Paying Agent or Conversion Agent, the Trustee
shall act as such and shall be entitled to appropriate compensation therefor
pursuant to Section 7.07.

      The Company initially appoints the Trustee as Paying Agent, Registrar and
Conversion Agent and designates the Corporate Trust Office of the Trustee for
the purposes enumerated in the first paragraph of this Section 2.03.

2.04  PAYING AGENT TO HOLD MONEY IN TRUST.

      Each Paying Agent shall hold in trust for the benefit of the
Securityholders or the Trustee all moneys and, if applicable, other property
held by the Paying Agent for the payment of the Securities, and shall notify the
Trustee of any Default by the Company in making any such payment. While any such
Default continues, the Trustee may require a Paying Agent to pay all money and,
if applicable, other property held by it to the Trustee. The Company at any time
may require a Paying Agent to pay all money and, if applicable, other property
held by it to the Trustee and account for any funds so paid by it. Upon payment
over to the Trustee, the Paying Agent shall have no further liability for such
money and, if applicable, other property. If the Company acts as Paying Agent,
it shall segregate and hold as a separate trust fund all money and, if
applicable, other property held by it as Paying Agent.

2.05  SECURITYHOLDER LISTS.

      The Trustee shall preserve in as current a form as is reasonably
practicable the most recent list available to it of the names and addresses of
Securityholders. If the Trustee is not the Registrar, the Company shall (i)
furnish to the Trustee on or before each interest payment date, a list of the
names and addresses of Securityholders appearing on the security register of the
Registrar; and (ii) furnish, within thirty (30) days after the receipt by the
Company of such request, to the Trustee, at such other times as the Trustee may
request in writing, a list of similar form and content, which list shall be as
of a date not more than fifteen (15) days before the date such list is
furnished.

2.06  TRANSFER AND EXCHANGE.

      Subject to Sections 2.15 and 2.16 hereof, where Securities are presented
to the Registrar with a request to register their transfer or to exchange them
for an equal principal amount of Securities of other authorized denominations,
the Registrar shall register the transfer or make the exchange if its
requirements for such transaction are met. To permit registrations of transfer
and exchanges, the Trustee shall authenticate Securities at the Registrar's
request or upon the Trustee's receipt of a Company Order therefor. The Company
or the Trustee, as the case may be, shall not be required to register the
transfer of or exchange any Security (i) for a period of fifteen (15) days
before selecting, pursuant to Section 3.03, Securities to be redeemed or (ii)
during a period beginning at the opening of business fifteen (15) days before
the mailing of a notice of redemption of the Securities selected for Redemption
under Section 3.04 and ending at the close of business on the day of such
mailing or (iii) that has been selected for Redemption or for which a Purchase
Notice has been delivered, and not withdrawn, in accordance with this

                                      -10-
<PAGE>
Indenture, except the unredeemed or unrepurchased portion of Securities being
redeemed or repurchased in part.

      No service charge shall be made for any transfer, exchange or conversion
of Securities, but the Company may require payment of a sum sufficient to cover
any transfer tax or similar governmental charge that may be imposed in
connection with any transfer, exchange or conversion of Securities, other than
exchanges pursuant to Sections 2.10, 9.05 or 10.02, or Article III, not
involving any transfer.

2.07  REPLACEMENT SECURITIES.

      If the Holder of a Security claims that the Security has been mutilated,
lost, destroyed or wrongfully taken, the Company shall, in the absence of notice
to the Company or the Trustee that such Security has been acquired by a bona
fide purchaser, issue and the Trustee, upon receipt of a Company Order therefor,
shall authenticate a replacement Security upon surrender to the Trustee of the
mutilated Security, or upon delivery to the Trustee of evidence of the loss,
destruction or theft of the Security satisfactory to the Trustee and the
Company. In the case of a lost, destroyed or wrongfully taken Security, the
Trustee or the Company may require the Holder of such Security to deliver, prior
to the issuance and authentication of a replacement Security, an indemnity bond
that is reasonably satisfactory to the Trustee and the Company to indemnify and
hold harmless the Company, the Trustee and any Security Agent from any loss
which any of them may suffer if such Security is replaced. The Company and the
Trustee may charge such Holder for their expenses (including taxes or
governmental charges incurred) in replacing a Security.

      In case any such mutilated, lost, destroyed or wrongfully taken Security
has become or is about to become due and payable (whether at maturity, upon
Redemption, on an Option Purchase Date with respect to a Purchase at Holder's
Option or on a Fundamental Change Repurchase Date with respect to a Repurchase
Upon Fundamental Change), the Company in its discretion may, instead of issuing
a new Security, pay such Security when due.

      Every replacement Security is an additional obligation of the Company only
as provided in Section 2.08.

2.08  OUTSTANDING SECURITIES.

      Securities outstanding at any time are all the Securities authenticated by
the Trustee except for those converted, those cancelled by it, those delivered
to it for cancellation and those described in this Section 2.08 as not
outstanding. Except to the extent provided in Section 2.09, a Security does not
cease to be outstanding because the Company or one of its Subsidiaries or
Affiliates holds the Security.

      If a Security is replaced pursuant to Section 2.07, it ceases to be
outstanding unless the Trustee receives proof satisfactory to it, or a court
holds, that the replaced Security is held by a bona fide purchaser.

      If the Paying Agent (other than the Company) holds on an Option Purchase
Date, Redemption Date, Fundamental Change Repurchase Date or Maturity Date,
money sufficient to

                                      -11-
<PAGE>
pay the aggregate Option Purchase Price, Redemption Price, Fundamental Change
Repurchase Price or principal amount, as the case may be, with respect to all
Securities to be redeemed, purchased or paid upon Purchase at Holder's Option,
Redemption, Repurchase Upon Fundamental Change or maturity, as the case may be,
in each case plus, if applicable, accrued and unpaid interest, if any, payable
as herein provided upon Purchase at Holder's Option, Redemption, Repurchase Upon
Fundamental Change or maturity, then (unless there shall be a Default in the
payment of such aggregate Option Purchase Price, Redemption Price, Fundamental
Change Repurchase Price or principal amount, or of such accrued and unpaid
interest) on and after such date such Securities shall be deemed to be no longer
outstanding, interest on such Securities shall cease to accrue, and such
Securities shall be deemed paid whether or not such Securities are delivered to
the Paying Agent. Thereafter, all rights of the Holders of such Securities shall
terminate with respect to such Securities, other than the right to receive the
Option Purchase Price, Redemption Price, Fundamental Change Repurchase Price or
principal amount, as the case may be, plus, if applicable, such accrued and
unpaid interest, in accordance with this Indenture.

      If a Security is converted in accordance with Article X, then, from and
after the time of such conversion on the Conversion Date, such Security shall
cease to be outstanding, and interest, if any, shall cease to accrue on such
Security.

2.09  SECURITIES HELD BY THE COMPANY OR AN AFFILIATE.

      In determining whether the Holders of the required aggregate principal
amount of Securities have concurred in any request, demand, direction, waiver or
consent, Securities owned by the Company or any of its Subsidiaries or
Affiliates shall be considered as though not outstanding, except that, for the
purposes of determining whether a Responsible Officer of the Trustee shall be
protected in relying on any such request, demand, direction, waiver or consent,
only Securities which the Trustee knows are so owned shall be so disregarded.
Securities so owned which have been pledged in good faith may be considered to
be outstanding for purposes of this Section 2.09 if the pledgee establishes, to
the satisfaction of the Trustee, the pledgee's right so to concur with respect
to such Securities and that the pledgee is not, and is not acting at the
direction or on behalf of, the Company, any other obligor on the Securities, an
Affiliate of the Company or an affiliate of any such other obligor. In the event
of a dispute as to whether the pledgee has established the foregoing, the
Trustee may rely on the advice of counsel or on an Officer's Certificate.

2.10  TEMPORARY SECURITIES.

      Until definitive Securities are ready for delivery, the Company may
prepare and the Trustee shall, upon its receipt of a Company Order therefor,
authenticate temporary Securities. Temporary Securities shall be substantially
in the form of definitive Securities but may have variations that the Company
considers appropriate for temporary Securities. Without unreasonable delay, the
Company shall prepare and the Trustee shall authenticate definitive Securities
in exchange for temporary Securities. Until so exchanged, each temporary
Security shall in all respects be entitled to the same benefits under this
Indenture as definitive Securities, and such temporary Security shall be
exchangeable for definitive Securities in accordance with the terms of this
Indenture.

                                      -12-
<PAGE>
2.11  CANCELLATION.

      The Company at any time may deliver Securities (which the Company may have
duly acquired in any manner whatsoever) to the Trustee for cancellation. The
Registrar, Paying Agent and Conversion Agent shall forward to the Trustee any
Securities surrendered to them for Redemption, Purchase at Holder's Option,
Repurchase Upon Fundamental Change, transfer, exchange, payment or conversion.
The Trustee shall promptly cancel all Securities surrendered for transfer,
exchange, payment (whether at maturity, upon Redemption, upon a Purchase at
Holder's Option, or upon a Repurchase Upon Fundamental Change), conversion or
cancellation in accordance with its customary procedures. The Company may not
issue new Securities to replace Securities that it has paid or delivered to the
Trustee for cancellation or that any Securityholder has converted pursuant to
Article X. All cancelled Securities held by the Trustee shall be destroyed, and
certification of their destruction shall be delivered by the Trustee to the
Company unless the Company shall, by a Company Order, direct that cancelled
Securities be returned to it.

2.12  DEFAULTED INTEREST.

      If and to the extent the Company defaults in a payment of interest on the
Securities, the Company shall pay in cash the defaulted interest in any lawful
manner plus, to the extent not prohibited by applicable statute or case law,
interest on such defaulted interest at the rate provided in the Securities. The
Company may pay the defaulted interest (plus interest on such defaulted
interest) to the persons who are Securityholders on a subsequent special record
date. The Company shall fix such record date and payment date. At least fifteen
(15) calendar days before such record date, the Company shall mail to
Securityholders a notice that states the record date, payment date and amount of
interest to be paid, and the Company shall cause any such defaulted interest
(plus interest on such defaulted interest) to be paid to Holders of record of
each applicable Security at 5:00 p.m., New York City time, on such record date.
Upon such due payment in full, such defaulted interest (plus interest on such
defaulted interest) shall no longer be payable pursuant to this Section 2.12.

2.13  CUSIP NUMBERS.

      The Company in issuing the Securities may use one or more "CUSIP" numbers,
and, if so, the Trustee shall use the CUSIP numbers in notices of redemption or
exchange as a convenience to Holders; provided, however, that no representation
is hereby deemed to be made by the Trustee as to the correctness or accuracy of
the CUSIP numbers printed on the notice or on the Securities; provided further,
that reliance may be placed only on the other identification numbers printed on
the Securities, and the effectiveness of any such notice shall not be affected
by any defect in, or omission of, such CUSIP numbers. The Company shall promptly
notify the Trustee of any change in the CUSIP numbers.

2.14  DEPOSIT OF MONEYS AND PROPERTY.

      Prior to 11:00 A.M., New York City time, on each interest payment date,
Maturity Date, Redemption Date, Option Purchase Date or Fundamental Change
Repurchase Date, the Company shall have deposited with a Paying Agent (or, if
the Company is acting as its own

                                      -13-
<PAGE>
Paying Agent, segregate and hold in trust in accordance with Section 2.04)
money, in funds immediately available on such date, and, if applicable as
provided herein, such other consideration, sufficient to make cash payments and
deliver such other consideration, if any, due on such interest payment date,
Maturity Date, Redemption Date, Option Purchase Date or Fundamental Change
Repurchase Date, as the case may be, in a timely manner which permits the Paying
Agent to remit payment to the Holders on such interest payment date, Maturity
Date, Redemption Date, Option Purchase Date or Fundamental Change Repurchase
Date, as the case may be. If, pursuant to Section 4.01 hereof and paragraph 3 of
the Securities, payment shall be made to Holders by check, then such deposit
shall be made in such manner as will permit such remittance to be made by check
drawn upon a bank in the city in which the Paying Agent's principal office, or
the Corporate Trust Office of the Trustee, shall be located.

2.15  BOOK-ENTRY PROVISIONS FOR GLOBAL SECURITIES.

      (A) The Global Securities initially shall (i) be registered in the name of
the Depositary or the nominee of the Depositary, (ii) be delivered to the
Trustee as custodian for the Depositary and (iii) bear legends as set forth in
Section 2.17.

      Members of, or participants in, the Depositary ("PARTICIPANTS") shall have
no rights under this Indenture with respect to any Global Security held on their
behalf by the Depositary, or the Trustee as its custodian, or under the Global
Security, and the Depositary may be treated by the Company, the Trustee and any
agent of the Company or the Trustee as the absolute owner of the Global Security
for all purposes whatsoever. Notwithstanding the foregoing, nothing herein shall
prevent the Company, the Trustee or any agent of the Company or the Trustee from
giving effect to any written certification, proxy or other authorization
furnished by the Depositary or impair, as between the Depositary and
Participants, the operation of customary practices governing the exercise of the
rights of a Holder of any Security.

      (B) Transfers of Global Securities shall be limited to transfers in whole,
but not in part, to the Depositary, its successors or their respective nominees.
In addition, Physical Securities shall be transferred to all beneficial owners,
as identified by the Depositary, in exchange for their beneficial interests in
Global Securities only if (i) the Depositary notifies the Company that the
Depositary is unwilling or unable to continue as depositary for any Global
Security (or the Depositary ceases to be a "clearing agency" registered under
Section 17A of the Exchange Act) and a successor Depositary is not appointed by
the Company within ninety (90) days of such notice or cessation or (ii) an Event
of Default has occurred and is continuing and the Registrar has received a
written request from the Depositary to issue Physical Securities.

      (C) In connection with the transfer of a Global Security in its entirety
to beneficial owners pursuant to Section 2.15(B), such Global Security shall be
deemed to be surrendered to the Trustee for cancellation, and the Company shall
execute, and the Trustee shall upon written instructions from the Company
authenticate and deliver, to each beneficial owner identified by the Depositary
in exchange for its beneficial interest in such Global Security, an equal
aggregate principal amount of Physical Securities of authorized denominations.


                                      -14-
<PAGE>

      (D) Any Physical Security constituting a Restricted Security delivered in
exchange for an interest in a Global Security pursuant to Section 2.15(B) shall,
except as otherwise provided by Section 2.16, bear the Private Placement Legend.

      (E) The Holder of any Global Security may grant proxies and otherwise
authorize any Person, including Participants and Persons that may hold interests
through Participants, to take any action which a Holder is entitled to take
under this Indenture or the Securities.

2.16  SPECIAL TRANSFER PROVISIONS.

      (A) RESTRICTIONS ON TRANSFER AND EXCHANGE OF GLOBAL SECURITIES.
Notwithstanding any other provisions of this Indenture, but except as provided
in Section 2.15(B), a Global Security may not be transferred except as a whole
by the Depositary to a nominee of the Depositary or by a nominee of the
Depositary to the Depositary or another nominee of the Depositary or by the
Depositary or any such nominee to a successor Depositary or a nominee of such
successor Depositary.

      (B) PRIVATE PLACEMENT LEGEND. Upon the transfer, exchange or replacement
of Securities not bearing the Private Placement Legend, the Registrar or
co-Registrar shall deliver Securities that do not bear the Private Placement
Legend. Upon the transfer, exchange or replacement of Securities bearing the
Private Placement Legend, the Registrar or co-Registrar shall deliver only
Securities that bear the Private Placement Legend unless (i) the requested
transfer is after the Resale Restriction Termination Date, (ii) there is
delivered to the Trustee and the Company an Opinion of Counsel (upon which
Opinion of Counsel the Trustee may conclusively rely) reasonably satisfactory to
the Company and addressed to the Company to the effect that neither such legend
nor the related restrictions on transfer are required in order to maintain
compliance with the provisions of the Securities Act or (iii) such Security has
been sold pursuant to an effective registration statement under the Securities
Act and the Holder selling such Securities has delivered to the Registrar or
co-Registrar a notice in the form of EXHIBIT C hereto. Upon the effectiveness,
under the Securities Act, of the "SHELF REGISTRATION STATEMENT" (as defined in
the Registration Rights Agreement), the Company shall deliver to the Trustee a
notice of effectiveness, a Global Security or Global Securities, which do not
bear the Private Placement Legend, an authentication order in accordance with
Section 2.02 and an Opinion of Counsel in the form of EXHIBIT D hereto, and, if
required by the Depositary, the Company shall deliver to the Depositary a letter
of representations in a form reasonably acceptable to the Depositary. Upon the
effectiveness of any post-effective amendment to the "Shelf Registration
Statement" (as defined in the Registration Rights Agreement) and upon the
effectiveness, under the Securities Act, of any "Subsequent Shelf Registration
Statement" (as defined in the Registration Rights Agreement), the Company shall
deliver to the Trustee a notice of effectiveness and an Opinion of Counsel in
the form of EXHIBIT D hereto. Upon any sale, pursuant to a Shelf Registration
Statement, of a beneficial interest in a Global Security that theretofore
constituted a Restricted Security and delivery of appropriate evidence thereof
to the Trustee, and upon any sale or transfer of a beneficial interest in
connection with which the Private Placement Legend will be removed in accordance
with this Indenture, the Trustee shall increase the principal amount of the
Global Security that does not constitute a Restricted Security by the principal
amount of such sale or transfer and likewise reduce the principal amount of the
Global Security that does constitute a Restricted Security.


                                      -15-
<PAGE>
      (C) GENERAL. By its acceptance of any Security bearing the Private
Placement Legend, each Holder of such a Security acknowledges the restrictions
on transfer of such Security set forth in this Indenture and in the Private
Placement Legend and agrees that it will transfer such Security only as provided
in this Indenture and as permitted by applicable law.

      The Registrar shall retain copies of all letters, notices and other
written communications received pursuant to Section 2.15 or this Section 2.16.
The Company shall have the right to inspect and make copies of all such letters,
notices or other written communications at any reasonable time during normal
hours of operation of the Registrar upon the giving of reasonable written notice
to the Registrar.

      (D) TRANSFERS OF SECURITIES HELD BY AFFILIATES. Any certificate (i)
evidencing a Security that has been transferred to an Affiliate within two (2)
years after the Issue Date, as evidenced by a notation on the assignment form
for such transfer or in the representation letter delivered in respect thereof
or (ii) evidencing a Security that has been acquired from an Affiliate (other
than by an Affiliate) in a transaction or a chain of transactions not involving
any public offering, shall, until two (2) years after the last date on which the
Company or any Affiliate was an owner of such Security (or such longer period of
time as may be required under the Securities Act or applicable state securities
laws), in each case, bear the Private Placement Legend, unless otherwise agreed
by the Company (with written notice thereof to the Trustee).

2.17  RESTRICTIVE LEGENDS.

      Each Global Security and Physical Security that constitutes a Restricted
Security shall bear the legend (the "PRIVATE PLACEMENT LEGEND") as set forth in
EXHIBIT B-1 on the face thereof until after the second anniversary of the later
of (i) the Issue Date and (ii) the last date on which the Company or any
Affiliate was the owner of such Security (or any predecessor security) (or such
shorter period of time as permitted by Rule 144(k) promulgated under under the
Securities Act or any successor provision thereunder) (or such longer period of
time as may be required under the Securities Act or applicable state securities
laws, as set forth in an Opinion of Counsel, unless otherwise agreed between the
Company and the Holder thereof) (such date, the "RESALE RESTRICTION TERMINATION
DATE").

      Each Global Security shall also bear the legend as set forth in EXHIBIT
B-2.

2.18  RANKING.

      The indebtedness of the Company arising under or in connection with this
Indenture and every outstanding Security issued under this Indenture from time
to time constitutes and will constitute a senior unsecured obligation of the
Company, ranking equally with other existing and future senior unsecured
indebtedness of the Company and ranking senior to any existing or future
indebtedness of the Company that, by its terms, is made subordinate to senior
indebtedness of the Company.


                                      -16-
<PAGE>
                         III. REDEMPTION AND REPURCHASE

3.01  RIGHT OF REDEMPTION.

      (A) Redemption of the Securities, as permitted by any provision of this
Indenture, shall be made:

            (i) with respect to a repurchase at the Company's option, in
      accordance with paragraphs 6 and 7 of the Securities (a "REDEMPTION"),

            (ii) with respect to a repurchase at the Holder's option, in
      accordance with paragraph 8 of the Securities (a "PURCHASE AT HOLDER'S
      OPTION") and

            (iii) with respect to any repurchase upon a Fundamental Change, in
      accordance with paragraph 9 of the Securities (a "REPURCHASE UPON
      FUNDAMENTAL CHANGE"),

      in each case in accordance with the applicable provisions of this Article
III.

      (B) The Company will comply with all federal and state securities laws,
and any applicable laws of any foreign jurisdiction, in connection with any
offer to sell or solicitations of offers to buy Securities pursuant to this
Article III.

      (C) The Company shall not have the right to redeem any Securities prior to
February 1, 2012. The Company shall have the right, at the Company's option, at
any time, and from time to time, on a Redemption Date on or after February 1,
2012, to redeem all or any part of the Securities at a price payable in cash
equal to the Redemption Price plus accrued and unpaid interest, if any, to, but
excluding, the Redemption Date.

      (D) Securities in denominations larger than $1,000 principal amount may be
redeemed in part but only in integral multiples of $1,000 principal amount.

3.02  NOTICES TO TRUSTEE.

      If the Company elects to redeem Securities pursuant to paragraph 6 of the
Securities, it shall notify the Trustee in writing of the Redemption Date, the
applicable provision of this Indenture pursuant to which the Redemption is to be
made and the aggregate principal amount of Securities to be redeemed, which
notice shall be provided to the Trustee by the Company at least fifteen (15)
days prior to the mailing, in accordance with Section 3.04, of the notice of
Redemption (unless a shorter notice period shall be satisfactory to the
Trustee).

3.03  SELECTION OF SECURITIES TO BE REDEEMED.

      If the Company has elected to redeem less than all the Securities pursuant
to paragraph 6 of the Securities, the Trustee shall, within five (5) Business
Days after receiving the notice specified in Section 3.02, select the Securities
to be redeemed by lot, on a pro rata basis or in accordance with any other
method the Trustee considers fair and appropriate. The Trustee shall make such
selection from Securities then outstanding and not already to be redeemed by
virtue


                                      -17-
<PAGE>
of having been previously called for Redemption. The Trustee may select for
Redemption portions of the principal amount of Securities that have
denominations larger than $1,000 principal amount. Securities and portions of
them the Trustee selects for Redemption shall be in amounts of $1,000 principal
amount or integral multiples of $1,000 principal amount. The Trustee shall
promptly notify the Company in writing of the Securities selected for Redemption
and the principal amount thereof to be redeemed.

      The Registrar need not register the transfer of or exchange any Securities
that have been selected for Redemption, except the unredeemed portion of the
Securities being redeemed in part. The Registrar need not issue, authenticate,
register the transfer of or exchange any Security for a period of fifteen (15)
days before selecting, pursuant to this Section 3.03, Securities to be redeemed.

3.04  NOTICE OF REDEMPTION.

      At least thirty (30) days but not more than sixty (60) days before a
Redemption Date, the Company shall mail, or cause to be mailed, by first-class
mail a notice of Redemption to each Holder whose Securities are to be redeemed,
at the address of such Holder appearing in the security register.

      The notice shall identify the Securities and the aggregate principal
amount thereof to be redeemed pursuant to the Redemption and shall state:

            (i) the Redemption Date;

            (ii) the Redemption Price plus accrued and unpaid interest, if any,
      to, but excluding, the Redemption Date;

            (iii) the Conversion Rate and the Conversion Price;

            (iv) the names and addresses of the Paying Agent and the Conversion
      Agent;

            (v) that the right to convert the Securities called for Redemption
      will terminate at the close of business on the third (3rd) Business Day
      immediately preceding the Redemption Date, unless there shall be a Default
      in the payment of the Redemption Price or accrued and unpaid interest, if
      any, payable as herein provided upon Redemption;

            (vi) that Holders who want to convert Securities must satisfy the
      requirements of Article X;

            (vii) the paragraph of the Securities pursuant to which the
      Securities are to be redeemed;

            (viii) that Securities called for Redemption must be surrendered to
      the Paying Agent to collect the Redemption Price plus accrued and unpaid
      interest, if any, payable as herein provided upon Redemption;


                                      -18-
<PAGE>
            (ix) that, unless there shall be a Default in the payment of the
      Redemption Price or accrued and unpaid interest, if any, payable as herein
      provided upon Redemption, interest on Securities called for Redemption
      ceases to accrue on and after the Redemption Date, such Securities will
      cease to be convertible after the close of business on the third (3rd)
      Business Day immediately preceding the Redemption Date, and all rights of
      the Holders of such Securities shall terminate on and after the Redemption
      Date, other than the right to receive, upon surrender of such Securities
      and in accordance with this Indenture, the Redemption Price and such
      accrued and unpaid interest; and

            (x) the CUSIP number or numbers, as the case may be, of the
      Securities.

      The right, pursuant to Article X, to convert Securities called for
Redemption shall terminate at the close of business on the third (3rd) Business
Day immediately preceding the Redemption Date, unless there shall be a Default
in the payment of the Redemption Price or accrued and unpaid interest, if any,
payable as herein provided upon Redemption.

      At the Company's request, upon reasonable prior notice, the Trustee shall
mail the notice of Redemption in the Company's name and at the Company's
expense; provided, however, that the form and content of such notice shall be
prepared by the Company.

3.05  EFFECT OF NOTICE OF REDEMPTION.

      Once notice of Redemption is mailed, Securities called for Redemption
become due and payable on the Redemption Date at the Redemption Price plus
accrued and unpaid interest to, but excluding, the Redemption Date, and, on and
after such Redemption Date (unless there shall be a Default in the payment of
the Redemption Price or such accrued and unpaid interest), such Securities shall
cease to bear interest, and all rights of the Holders of such Securities shall
terminate, other than the right to receive, upon surrender of such Securities
and in accordance with the next sentence, the Redemption Price and such accrued
and unpaid interest. Upon surrender to the Paying Agent of a Security subject to
Redemption, such Security shall be paid, to the Holder surrendering such
Security, at the Redemption Price plus accrued and unpaid interest to, but
excluding, the Redemption Date, unless the Redemption Date is an interest
payment date, in which case such accrued and unpaid interest will instead be
paid on such interest payment date to the Holder of record of such Security at
the close of business on the record date for such interest payment.

      If any Security shall not be fully and duly paid upon surrender thereof
for Redemption, the principal of, and accrued and unpaid interest on, such
Security shall, until paid, bear interest from, and including, the Redemption
Date at the rate borne by such Security on the principal amount of such
Security, and such Security shall continue to be convertible pursuant to Article
X.

      Notwithstanding anything herein to the contrary, there shall be no
purchase of any Securities pursuant to a Redemption if there has occurred (prior
to, on or after, as the case may be, the mailing of the notice of Redemption
specified in Section 3.04) and is continuing an Event of Default (other than a
Default in the payment of the Redemption Price or accrued and unpaid


                                      -19-
<PAGE>
interest, if any, payable as herein provided upon Redemption). The Paying Agent
will promptly return to the respective Holders thereof any Securities held by it
during the continuance of such an Event of Default.

3.06  DEPOSIT OF REDEMPTION PRICE.

      Prior to 11:00 A.M., New York City time on the Redemption Date, the
Company shall deposit with a Paying Agent (or, if the Company is acting as its
own Paying Agent, segregate and hold in trust in accordance with Section 2.04)
money, in funds immediately available on the Redemption Date, sufficient to pay
the Redemption Price, plus accrued and unpaid interest to, but excluding, the
Redemption Date, of all Securities to be redeemed on that date. The Paying Agent
shall return to the Company, as soon as practicable, any money not required for
that purpose.

3.07  SECURITIES REDEEMED IN PART.

      Any Security to be submitted for Redemption only in part shall be
delivered pursuant to Section 3.05 (with, if the Company or the Trustee so
requires, due endorsement by, or a written instrument of transfer in form
satisfactory to the Company and the Trustee duly executed by, the Holder thereof
or its attorney duly authorized in writing). Upon receipt of such Security
together with any such required endorsements or transfer instruments, the
Company shall execute, and the Trustee shall, upon its receipt of a Company
Order therefor, authenticate and make available for delivery to the Holder of
such Security without service charge, a new Security or Securities, of any
authorized denomination as requested by such Holder, of the same tenor and in
aggregate principal amount equal to the portion of such Security not submitted
for Redemption.

      If any Security selected for partial Redemption is converted in part, the
principal of such Security subject to Redemption shall be reduced by the
principal amount of such Security that is converted.

3.08  PURCHASE OF SECURITIES AT OPTION OF THE HOLDER.

      (A) At the option of the Holder thereof, Securities (or portions thereof
that are integral multiples of $1,000 in principal amount) shall be purchased by
the Company pursuant to paragraph 8 of the Securities on February 1, 2012,
February 1, 2015 and February 1, 2020 (each, an "OPTION PURCHASE DATE"), at a
purchase price, payable in cash, equal to one hundred percent (100%) of the
principal amount of the Securities (or such portions thereof) to be so purchased
(the "OPTION PURCHASE PRICE"), plus accrued and unpaid interest, if any, to, but
excluding, the applicable Option Purchase Date, upon:

            (i) delivery to the Company (if it is acting as its own Paying
      Agent), or to a Paying Agent designated by the Company for such purpose in
      the Option Purchase Notice (as defined below), by such Holder, at any time
      from 9:00 a.m., New York City time, on the date that is twenty (20)
      Business Days prior to the applicable Option Purchase Date until 5:00
      p.m., New York City time, on the third (3rd) Business Day immediately
      preceding the applicable Option Purchase Date, of a Purchase Notice, in
      the form set forth in the Securities (or any other form of written notice
      delivered in


                                      -20-
<PAGE>
      good faith and substantially similar thereto), duly completed and signed,
      with appropriate signature guarantee, stating:

                  (a) the certificate number(s) of the Securities which the
            Holder will deliver to be purchased, if such Securities are in the
            form of Physical Securities;

                  (b) the principal amount of Securities to be purchased, which
            must be $1,000 or an integral multiple thereof; and

                  (c) that such principal amount of Securities are to be
            purchased as of the applicable Option Purchase Date pursuant to the
            terms and conditions specified in paragraph 8 of the Securities and
            in this Indenture; and

            (ii) delivery to the Company (if it is acting as its own Paying
      Agent), or to a Paying Agent designated by the Company for such purpose in
      the Option Purchase Notice, at any time after delivery of such Purchase
      Notice, of such Securities (such Securities to conform in all material
      respects to the description thereof in the related Option Purchase
      Notice), together with all necessary endorsements, such delivery being a
      condition to receipt by the Holder of the Option Purchase Price therefor
      plus accrued and unpaid interest, if any, payable as herein provided upon
      Purchase at Holder's Option;

      If such Securities are held in book-entry form through the Depositary, the
Purchase Notice shall comply with applicable procedures of the Depositary.

      Upon such delivery of Securities to the Company (if it is acting as its
own Paying Agent) or such Paying Agent, such Holder shall be entitled, upon
request, to receive from the Company or such Paying Agent, as the case may be, a
nontransferable receipt of deposit evidencing such delivery.

      Notwithstanding anything herein to the contrary, any Holder that has
delivered the Purchase Notice contemplated by this Section 3.08(A) to the
Company (if it is acting as its own Paying Agent) or to a Paying Agent
designated by the Company for such purpose in the Option Purchase Notice shall
have the right to withdraw such Purchase Notice by delivery, at any time prior
to 5:00 p.m., New York City time, on the third (3rd) Business Day immediately
preceding the applicable Option Purchase Date, of a written notice of withdrawal
to the Company (if acting as its own Paying Agent) or the Paying Agent, which
notice shall contain the information specified in Section 3.08(B)(vii).

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

      (B) The Company shall give notice (the "OPTION PURCHASE NOTICE") on a date
not less than twenty (20) Business Days prior to each Option Purchase Date to
all Holders at their addresses shown in the register of the Registrar and to
beneficial owners as required by applicable law. Such notice shall state:


                                      -21-
<PAGE>
            (i) the Option Purchase Price plus accrued and unpaid interest, if
      any, to, but excluding, such Option Purchase Date and the Conversion Rate;

            (ii) the names and addresses of the Paying Agent and the Conversion
      Agent;

            (iii) that Securities with respect to which a Purchase Notice is
      given by a Holder may be converted pursuant to Article X only if such
      Purchase Notice has been withdrawn in accordance with this Section 3.08 or
      if there shall be a Default in the payment of such Option Purchase Price
      or in accrued and unpaid interest, if any, payable as herein provided upon
      Purchase at Holder's Option;

            (iv) that Securities must be surrendered (together with any
      necessary endorsements) to the Paying Agent to collect payment of the
      Option Purchase Price plus accrued and unpaid interest, if any, payable as
      herein provided upon Purchase at Holder's Option;

            (v) that the Option Purchase Price, plus accrued and unpaid
      interest, if any, to, but excluding, such Option Purchase Date, for any
      Security as to which a Purchase Notice has been given and not withdrawn
      will be paid as promptly as practicable, but in no event more than three
      (3) Business Days, following the later of such Option Purchase Date or the
      time of delivery of the Security as described in clause (iv) above;

            (vi) the procedures the Holder must follow to exercise rights under
      this Section 3.08 (including the name and address of the Paying Agent) and
      a brief description of those rights;

            (vii) that a Holder will be entitled to withdraw its election in the
      Purchase Notice if the Company (if acting as its own Paying Agent) or the
      Paying Agent receives, at any time prior to 5:00 p.m., New York City time,
      on the third (3rd) Business Day immediately preceding the applicable
      Option Purchase Date, or such longer period as may be required by law, a
      letter or telegram, telex or facsimile transmission (receipt of which is
      confirmed and promptly followed by a letter) setting forth (I) the name of
      such Holder, (II) a statement that such Holder is withdrawing its election
      to have Securities purchased by the Company on such Option Purchase Date
      pursuant to a Purchase at Holder's Option, (III) the certificate number of
      such Securities to be so withdrawn (if such Securities are in the form of
      Physical Securities), (IV) the principal amount of the Securities of such
      Holder to be so withdrawn, which amount must be $1,000 or an integral
      multiple thereof and (V) the principal amount, if any, of the Securities
      of such Holder that remain subject to the Purchase Notice delivered by
      such Holder in accordance with this Section 3.08, which amount must be
      $1,000 or an integral multiple thereof;

            (viii) that, on and after the applicable Option Purchase Date
      (unless there shall be a Default in the payment of such Option Purchase
      Price or such accrued and unpaid interest), interest on Securities subject
      to Purchase at Holder's Option will


                                      -22-
<PAGE>
      cease to accrue, and all rights of the Holders of such Securities shall
      terminate, other than the right to receive, upon surrender of such
      Securities and in accordance with this Section 3.08, the Option Purchase
      Price and such accrued and unpaid interest; and

            (ix) the CUSIP number or numbers, as the case may be, of the
      Securities.

      At the Company's request, upon reasonable prior notice, the Trustee shall
mail such Option Purchase Notice in the Company's name and at the Company's
expense; provided, however, that the form and content of such Option Purchase
Notice shall be prepared by the Company.

      No failure of the Company to give an Option Purchase Notice shall limit
any Holder's right pursuant hereto to exercise its rights to require the Company
to purchase such Holder's Securities pursuant to a Purchase at Holder's Option.

      (C) Subject to the provisions of this Section 3.08, the Company shall pay,
or cause to be paid, the Option Purchase Price, plus accrued and unpaid
interest, if any, to, but excluding, the applicable Option Purchase Date, with
respect to each Security subject to Purchase at Holder's Option to the Holder of
record thereof as promptly as practicable, but in no event more than three (3)
Business Days, following the later of the applicable Option Purchase Date and
the time such Security (together with all necessary endorsements) is surrendered
to the Paying Agent.

      (D) Prior to 11:00 A.M., New York City time on the applicable Option
Purchase Date, the Company shall deposit with a Paying Agent (or, if the Company
is acting as its own Paying Agent, segregate and hold in trust in accordance
with Section 2.04) money, in funds immediately available on the applicable
Option Purchase Date, sufficient to pay the Option Purchase Price, plus accrued
and unpaid interest, if any, to, but excluding, such Option Purchase Date, of
all of the Securities that are to be purchased by the Company on such Option
Purchase Date pursuant to a Purchase at Holder's Option. The Paying Agent shall
return to the Company, as soon as practicable, any money not required for that
purpose.

      (E) Once the Purchase Notice has been duly delivered in accordance with
this Section 3.08, the Securities to be purchased pursuant to the Purchase at
Holder's Option shall, on the applicable Option Purchase Date, become due and
payable at the Option Purchase Price (plus accrued and unpaid interest, if any,
to, but excluding, such Option Purchase Date) applicable thereto, and, on and
after such date (unless there shall be a Default in the payment of the Option
Purchase Price or such accrued and unpaid interest), such Securities shall cease
to bear interest, and all rights of the Holders of such Securities shall
terminate, other than the right to receive, in accordance with this Section
3.08, the Option Purchase Price and such accrued and unpaid interest.

      (F) Securities with respect to which a Purchase Notice has been duly
delivered in accordance with this Section 3.08 may be converted pursuant to
Article X, if otherwise convertible in accordance with Article X, only if such
Purchase Notice has been withdrawn in accordance with this Section 3.08 or if
there shall be a Default in the payment of the Option Purchase Price or in the
accrued and unpaid interest, if any, payable as herein provided upon Purchase at
Holder's Option.


                                      -23-
<PAGE>
      (G) If any Security shall not be paid upon surrender thereof for Purchase
at Holder's Option, the principal of, and accrued and unpaid interest on, such
Security shall, until paid, bear interest from, and including, the applicable
Option Purchase Date at the rate borne by such Security on the principal amount
of such Security, and such Security shall continue to be convertible pursuant to
Article X.

      (H) Any Security which is to be submitted for Purchase at Holder's Option
only in part shall be delivered pursuant to this Section 3.08 (with, if the
Company or the Trustee so requires, due endorsement by, or a written instrument
of transfer in form satisfactory to the Company and the Trustee duly executed
by, the Holder thereof or its attorney duly authorized in writing), and the
Company shall execute, and the Trustee shall authenticate and make available for
delivery to the Holder of such Security without service charge, a new Security
or Securities, of any authorized denomination as requested by such Holder, of
the same tenor and in aggregate principal amount equal to the portion of such
Security not submitted for Purchase at Holder's Option.

      (I) Notwithstanding anything herein to the contrary, there shall be no
purchase of any Securities pursuant to this Section 3.08 if there has occurred
(prior to, on or after, as the case may be, the giving, by the Holders of such
Securities, of the required Purchase Notice) and is continuing an Event of
Default (other than a Default in the payment of the Option Purchase Price or
accrued and unpaid interest, if any, payable as herein provided upon Purchase at
Holder's Option or a Default arising from the Company's failure to provide the
applicable Option Purchase Notice). The Paying Agent will promptly return to the
respective Holders thereof any Securities held by it during the continuance of
an Event of Default (other than a Default in the payment of the Option Purchase
Price or such accrued and unpaid interest).

      (J) Notwithstanding anything herein to the contrary, if the option granted
to Holders to require the purchase of the Securities on the applicable Option
Purchase Date is determined to constitute a tender offer, the Company shall
comply with all applicable tender offer rules under the Exchange Act, including
Rule 13e-4 and Regulation 14E, and with all other applicable laws, and will file
a Schedule TO or any other schedules required under the Exchange Act or any
other applicable laws.

3.09  REPURCHASE AT OPTION OF HOLDER UPON A FUNDAMENTAL CHANGE.

      (A) In the event any Fundamental Change (as defined below) shall occur,
each Holder of Securities shall have the right (the "FUNDAMENTAL CHANGE
REPURCHASE RIGHT"), at such Holder's option, to require the Company to
repurchase all of such Holder's Securities (or portions thereof that are
integral multiples of $1,000 in principal amount), on a date selected by the
Company (the "FUNDAMENTAL CHANGE REPURCHASE DATE"), which Fundamental Change
Repurchase Date shall be no later than thirty (30) days after the date the
Fundamental Change Notice (as defined below) is mailed in accordance with
Section 3.09(B), at a price, payable in cash, equal to one hundred percent
(100%) of the principal amount of the Securities (or portions thereof) to be so
repurchased (the "FUNDAMENTAL CHANGE REPURCHASE PRICE"), plus accrued and unpaid
interest, if any, to, but excluding, the Fundamental Change Repurchase Date,
upon:


                                      -24-
<PAGE>
            (i) delivery to the Company (if it is acting as its own Paying
      Agent), or to a Paying Agent designated by the Company for such purpose in
      the Fundamental Change Notice, no later than 5:00 p.m., New York City
      time, on the third (3rd) Business Day immediately preceding the
      Fundamental Change Repurchase Date, of a Purchase Notice, in the form set
      forth in the Securities (or any other form of written notice delivered in
      good faith and substantially similar thereto), duly completed and signed,
      with appropriate signature guarantee, stating:

                  (a) the certificate number(s) of the Securities which the
            Holder will deliver to be repurchased, if such Securities are in the
            form of Physical Securities;

                  (b) the principal amount of Securities to be repurchased,
            which must be $1,000 or an integral multiple thereof; and

                  (c) that such principal amount of Securities are to be
            repurchased pursuant to the terms and conditions specified in
            paragraph 9 of the Securities and in this Indenture; and

            (ii) delivery to the Company (if it is acting as its own Paying
      Agent), or to a Paying Agent designated by the Company for such purpose in
      the Fundamental Change Notice, at any time after the delivery of such
      Purchase Notice, of such Securities (such Securities to conform in all
      material respects to the description thereof in the related Purchase
      Notice), together with all necessary endorsements, with respect to which
      the Fundamental Change Repurchase Right is being exercised, such delivery
      being a condition to receipt by the Holder of the Fundamental Change
      Repurchase Price therefor plus accrued and unpaid interest, if any,
      payable as herein provided upon Repurchase Upon Fundamental Change.

      If such Securities are held in book-entry form through the Depositary, the
Purchase Notice shall comply with applicable procedures of the Depositary.

      Upon such delivery of Securities to the Company (if it is acting as its
own Paying Agent) or such Paying Agent, such Holder shall be entitled to receive
from the Company or such Paying Agent, as the case may be, a nontransferable
receipt of deposit evidencing such delivery.

      Notwithstanding anything herein to the contrary, any Holder that has
delivered the Purchase Notice contemplated by this Section 3.09(A) to the
Company (if it is acting as its own Paying Agent) or to a Paying Agent
designated by the Company for such purpose in the Fundamental Change Notice
shall have the right to withdraw such Purchase Notice by delivery, at any time
prior to 5:00 p.m., New York City time, on the third (3rd) Business Day
immediately preceding the Fundamental Change Repurchase Date, of a written
notice of withdrawal to the Company (if acting as its own Paying Agent) or the
Paying Agent, which notice shall contain the information specified in Section
3.09(B)(xi).

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


                                      -25-
<PAGE>
      (B) Within thirty (30) days after the occurrence of a Fundamental Change,
the Company shall mail, or cause to be mailed, to all Holders of record of the
Securities at their addresses shown in the register of the Registrar, and to
beneficial owners as required by applicable law, a notice (the "FUNDAMENTAL
CHANGE NOTICE") of the occurrence of such Fundamental Change and the Fundamental
Change Repurchase Right arising as a result thereof. The Company shall deliver a
copy of the Fundamental Change Notice to the Trustee and shall publicly
announce, through a reputable national newswire service, the occurrence of each
Fundamental Change.

      Each Fundamental Change Notice shall state:

            (i) the events causing the Fundamental Change;

            (ii) the date of such Fundamental Change;

            (iii) the Fundamental Change Repurchase Date;

            (iv) the date by which the Fundamental Change Repurchase Right must
      be exercised;

            (v) the Fundamental Change Repurchase Price plus accrued and unpaid
      interest, if any, to, but excluding, the Fundamental Change Repurchase
      Date;

            (vi) the names and addresses of the Paying Agent and the Conversion
      Agent;

            (vii) a description of the procedures which a Holder must follow to
      exercise the Fundamental Change Repurchase Right;

            (viii) that, in order to exercise the Fundamental Change Repurchase
      Right, the Securities (together with all necessary endorsements) must be
      surrendered for payment of the Fundamental Change Repurchase Price plus
      accrued and unpaid interest, if any, payable as herein provided upon
      Repurchase Upon Fundamental Change;

            (ix) that the Fundamental Change Repurchase Price, plus accrued and
      unpaid interest, if any, to, but excluding, the Fundamental Change
      Repurchase Date, for any Security as to which a Purchase Notice has been
      given and not withdrawn will be paid as promptly as practicable, but in no
      event more than three (3) Business Days, following the later of such
      Fundamental Change Repurchase Date and the time of delivery of the
      Security (together with all necessary endorsements) as described in clause
      (VIII) above;

            (x) that, on and after such Fundamental Change Repurchase Date
      (unless there shall be a Default in the payment of such Fundamental Change
      Repurchase Price or such accrued and unpaid interest), interest on
      Securities subject to Repurchase Upon Fundamental Change will cease to
      accrue, and all rights of the Holders of such Securities shall terminate,
      other than the right to receive, upon surrender of such


                                      -26-
<PAGE>
      Securities (together with all necessary endorsements), the Fundamental
      Change Repurchase Price and such accrued and unpaid interest;

            (xi) that a Holder will be entitled to withdraw its election in the
      Purchase Notice if the Company (if acting as its own Paying Agent), or the
      Paying Agent receives, prior to 5:00 p.m., New York City time, on the
      third (3rd) Business Day immediately preceding the Fundamental Change
      Repurchase Date, or such longer period as may be required by law, a letter
      or telegram, telex or facsimile transmission (receipt of which is
      confirmed and promptly followed by a letter) setting forth (I) the name of
      such Holder, (II) a statement that such Holder is withdrawing its election
      to have Securities purchased by the Company on such Fundamental Change
      Repurchase Date pursuant to a Repurchase Upon Fundamental Change, (III)
      the certificate number of such Securities to be so withdrawn (if such
      Securities are in the form of Physical Securities), (IV) the principal
      amount of the Securities of such Holder to be so withdrawn, which amount
      must be $1,000 or an integral multiple thereof and (V) the principal
      amount, if any, of the Securities of such Holder that remain subject to
      the Purchase Notice delivered by such Holder in accordance with this
      Section 3.09, which amount must be $1,000 or an integral multiple thereof;

            (xii) the Conversion Rate and any adjustments to the Conversion Rate
      that will result from such Fundamental Change;

            (xiii) that Securities with respect to which a Purchase Notice is
      given by a Holder may be converted pursuant to Article X only if such
      Purchase Notice has been withdrawn in accordance with this Section 3.09 or
      if there shall be a Default in the payment of the Fundamental Change
      Repurchase Price or in the accrued and unpaid interest, if any, payable as
      herein provided upon Repurchase Upon Fundamental Change; and

            (xiv) the CUSIP number or numbers, as the case may be, of the
      Securities.

      At the Company's request, upon reasonable prior notice, the Trustee shall
mail such Fundamental Change Notice in the Company's name and at the Company's
expense; provided, however, that the form and content of such Fundamental Change
Notice shall be prepared by the Company.

      No failure of the Company to give a Fundamental Change Notice shall limit
any Holder's right pursuant hereto to exercise a Fundamental Change Repurchase
Right.

      (C) Subject to the provisions of this Section 3.09, the Company shall pay,
or cause to be paid, the Fundamental Change Repurchase Price, plus accrued and
unpaid interest, if any, to, but excluding, the Fundamental Change Repurchase
Date, with respect to each Security as to which the Fundamental Change
Repurchase Right shall have been exercised to the Holder thereof as promptly as
practicable, but in no event more than three (3) Business Days, following the
later of the Fundamental Change Repurchase Date and the time such Security is
surrendered to the Paying Agent.


                                      -27-
<PAGE>
      (D) Prior to 11:00 A.M., New York City time on a Fundamental Change
Repurchase Date, the Company shall deposit with a Paying Agent (or, if the
Company is acting as its own Paying Agent, segregate and hold in trust in
accordance with Section 2.04) money, in funds immediately available on the
Fundamental Change Repurchase Date, sufficient to pay the Fundamental Change
Repurchase Price, plus accrued and unpaid interest, if any, to, but excluding,
the Fundamental Change Repurchase Date, of all of the Securities that are to be
repurchased by the Company on such Fundamental Change Repurchase Date pursuant
to a Repurchase Upon Fundamental Change. The Paying Agent shall return to the
Company, as soon as practicable, any money not required for that purpose.

      (E) Once the Fundamental Change Notice and the Purchase Notice have been
duly given in accordance with this Section 3.09, the Securities to be
repurchased pursuant to a Repurchase Upon Fundamental Change shall, on the
Fundamental Change Repurchase Date, become due and payable at the Fundamental
Change Repurchase Price (plus accrued and unpaid interest, if any, to, but
excluding, the Fundamental Change Repurchase Date) applicable thereto, and, on
and after such date (unless there shall be a Default in the payment of the
Fundamental Change Repurchase Price or such accrued and unpaid interest), such
Securities shall cease to bear interest, and all rights of the Holders of such
Securities shall terminate, other than the right to receive, in accordance with
this Section 3.09, the Fundamental Change Repurchase Price and such accrued and
unpaid interest.

      (F) Securities with respect to which a Purchase Notice has been duly
delivered in accordance with this Section 3.09 may be converted pursuant to
Article X, if otherwise convertible in accordance with Article X, only if such
Purchase Notice has been withdrawn in accordance with this Section 3.09 or if
there shall be a Default in the payment of the Fundamental Change Repurchase
Price or in the accrued and unpaid interest, if any, payable as herein provided
upon Repurchase Upon Fundamental Change.

      (G) If any Security shall not be paid upon surrender thereof for
Repurchase Upon Fundamental Change, the principal of, and accrued and unpaid
interest on, such Security shall, until paid, bear interest, payable in cash,
from, and including, the Fundamental Change Repurchase Date at the rate borne by
such Security on the principal amount of such Security, and such Security shall
continue to be convertible pursuant to Article X.

      (H) Any Security which is to be submitted for Repurchase Upon Fundamental
Change only in part shall be delivered pursuant to this Section 3.09 (with, if
the Company or the Trustee so requires, due endorsement by, or a written
instrument of transfer in form satisfactory to the Company and the Trustee duly
executed by, the Holder thereof or its attorney duly authorized in writing), and
the Company shall execute, and the Trustee shall authenticate and make available
for delivery to the Holder of such Security without service charge, a new
Security or Securities, of any authorized denomination as requested by such
Holder, of the same tenor and in aggregate principal amount equal to the portion
of such Security not duly submitted for Repurchase Upon Fundamental Change.

      (I) Notwithstanding anything herein to the contrary, there shall be no
purchase of any Securities pursuant to this Section 3.09 if there has occurred
(prior to, on or after, as the case may be, the giving, by the Holders of such
Securities, of the required Purchase Notice) and is


                                      -28-
<PAGE>
continuing an Event of Default (other than a Default in the payment of the
Fundamental Change Repurchase Price or accrued and unpaid interest, if any,
payable as herein provided upon Repurchase Upon Fundamental Change or a Default
arising from the Company's failure to provide the applicable Fundamental Change
Notice). The Paying Agent will promptly return to the respective Holders thereof
any Securities held by it during the continuance of an Event of Default (other
than a Default in the payment of the Fundamental Change Repurchase Price or such
accrued and unpaid interest).

      (J) Notwithstanding anything herein to the contrary, if the option granted
to Holders to require the repurchase of the Securities upon the occurrence of a
Fundamental Change is determined to constitute a tender offer, the Company shall
comply with all applicable tender offer rules under the Exchange Act, including
Rule 13e-4 and Regulation 14E, and with all other applicable laws, and will file
a Schedule TO or any other schedules required under the Exchange Act or any
other applicable laws.

      (K) As used herein and in the Securities, a "FUNDAMENTAL CHANGE" shall be
deemed to have occurred upon the occurrence, on or after the Issue Date, of
either a "Change in Control" or a "Termination of Trading."

            (i) A "CHANGE IN CONTROL" shall be deemed to have occurred at such
      time as:

                  (a) any "person" or "group" (as such terms are used for
            purposes of Sections 13(d) and 14(d) of the Exchange Act), other
            than the Company, any Subsidiary or any employee benefit plan of the
            Company, is or becomes the "beneficial owner" (as such term is used
            in Rule 13d-3 under the Exchange Act), directly or indirectly, of
            fifty percent (50%) or more of the Voting Stock of the Company (such
            an event, an "ACQUISITION OF VOTING CONTROL"); or

                  (b) there occurs a sale, transfer, lease, conveyance or other
            disposition of all or substantially all of the property or assets of
            the Company to any "person" or "group" (as such terms are used in
            Sections 13(d) and 14(d) of the Exchange Act), including any group
            acting for the purpose of acquiring, holding, voting or disposing of
            securities within the meaning of Rule 13d-5(b)(1) under the Exchange
            Act (such an occurrence, a "QUALIFYING ASSET SALE"); or

                  (c) the Company consolidates with, or merges with or into,
            another person or any person consolidates with, or merges with or
            into, the Company, unless either:

                        (1) the persons that "beneficially owned" (as such term
                  is used in Rule 13d-3 under the Exchange Act), directly or
                  indirectly, the shares of the Company's Voting Stock
                  immediately prior to such consolidation or merger,
                  "beneficially own," directly or indirectly, immediately after
                  such consolidation or merger, shares of the surviving or
                  continuing corporation's Voting Stock representing at least a
                  majority of the total voting power of all outstanding classes
                  of the Voting Stock of the


                                      -29-
<PAGE>
                  surviving or continuing corporation in substantially the same
                  proportion as such ownership immediately prior to such
                  consolidation or merger; or

                        (2) at least ninety percent (90%) of the consideration
                  (other than cash payments for fractional shares or pursuant to
                  statutory appraisal rights) in such consolidation or merger
                  consists of common stock and any associated rights traded on a
                  U.S. national securities exchange or quoted on the Nasdaq
                  National Market (or which will be so traded or quoted when
                  issued or exchanged in connection with such consolidation or
                  merger), and, as a result of such consolidation or merger, the
                  Securities become convertible solely into such common stock,
                  associated rights and cash for fractional shares

            (such a consolidation or merger that does not satisfy the conditions
            set forth in the immediately preceding clauses (1) or (2), a
            "QUALIFYING BUSINESS COMBINATION"); or

                  (d) the following persons cease for any reason to constitute a
            majority of the Company's Board of Directors:

                        (1) individuals who on the Issue Date constituted the
                  Company's Board of Directors; and

                        (2) any new directors whose election to the Company's
                  Board of Directors or whose nomination for election by the
                  Company's stockholders was approved by at least a majority of
                  the directors of the Company then still in office either who
                  were directors of the Company on the Issue Date or whose
                  election or nomination for election was previously so
                  approved; or

                  (e) the Company is liquidated or dissolved or the holders of
            the Company's Capital Stock approve any plan or proposal for the
            liquidation or dissolution of the Company.

            (ii) A "TERMINATION OF TRADING" shall be deemed to occur if the
      Common Stock of the Company (or other common stock into which the
      Securities are then convertible) is neither listed for trading on a U.S.
      national securities exchange nor approved for trading on an established
      automated over-the-counter trading market in the United States.

            (iii) Notwithstanding any provision of Section 3.09(K)(i)(b) to the
      contrary, a strategic licensing arrangement, or a corporate partnering
      transaction or similar collaboration, involving one or more of the
      Company's product candidates, products or intellectual property, whether
      in a single transaction or a series of transactions, shall be deemed not
      to be a Qualifying Asset Sale if:

                  (a) the Company has obtained an opinion of a nationally
            recognized counsel reasonably satisfactory to the Trustee, dated the
            effective date of such


                                      -30-
<PAGE>
            transaction or series of transactions, addressed to the Trustee and
            in form and substance reasonably satisfactory to the Trustee, to the
            effect that such transaction or series of transactions does not,
            individually or in the aggregate, constitute a sale, transfer,
            lease, conveyance or other disposition of all or substantially all
            of the property or assets of the Company to any "person" or "group"
            (as such terms are used in Sections 13(d) and 14(d) of the Exchange
            Act), including any group acting for the purpose of acquiring,
            holding, voting or disposing of securities within the meaning of
            Rule 13d-5(b)(1) under the Exchange Act; and

                  (b) at the effective time of such transaction or series of
            transactions, a court of competent jurisdiction has not rendered a
            judgment or order that is binding on the Company and that prohibits
            the Company from proceeding with such transaction or series of
            transactions on the terms then proposed or that requires the Company
            to obtain the authorization or consent of the Company's stockholders
            in connection with such transaction or series of transactions
            pursuant to Section 271 of the Delaware General Corporation Law or
            any similar law that may then be applicable to the Company.

                  A transaction or series of transactions that satisfies the
          requirements of this Section 3.09(K)(iii) is herein referred to as a
          "PERMITTED STRATEGIC TRANSACTION."

3.10  CONVERSION ARRANGEMENT ON CALL FOR REDEMPTION.

      In connection with a Redemption of Securities, the Company may arrange, in
lieu of Redemption, for the purchase and conversion of any Securities called for
Redemption by an agreement with one or more investment banks or other purchasers
to purchase all or a portion of such Securities by paying, on or before 11:00
A.M., New York City time on the Redemption Date, to the Paying Agent in trust
for the Holders whose Securities are to be so purchased, an amount of money, in
funds immediately available on the Redemption Date, that, together with any
amounts deposited with the Paying Agent by the Company for Redemption of such
Securities, is not less than the aggregate Redemption Price, together with
accrued and unpaid interest, if any, to, but excluding, the Redemption Date, of
such Securities. Notwithstanding anything to the contrary contained in this
Article III, the obligation of the Company to pay the Redemption Price of such
Securities, including all accrued interest, if any, shall be deemed to be
satisfied and discharged to the extent such amount is so paid by such
purchasers, but no such agreement shall relieve the Company of its obligation to
pay such Redemption Price or such accrued and unpaid interest, if any. If such
an agreement is entered into, any Securities not duly surrendered for conversion
by the Holders thereof may, at the option of the Company, be deemed, to the
fullest extent permitted by law, acquired by such purchasers from such Holders
and (notwithstanding anything to the contrary contained in Article X)
surrendered by such purchasers for conversion, all as of immediately prior to
the close of business on the Redemption Date, subject to payment of the above
amount as aforesaid. The Paying Agent shall hold and pay to the Holders whose
Securities are selected for Redemption any such amount paid to it for purchase
and conversion in the same manner as it would moneys deposited with it by the
Company for the Redemption of Securities. Without the prior written consent of
the Trustee and the Paying Agent, no arrangement between the Company and such
purchasers for the purchase


                                      -31-
<PAGE>
and conversion of any Securities shall increase or otherwise affect any of the
powers, duties, rights, immunities, responsibilities or obligations of the
Trustee or Paying Agent as set forth in this Indenture, and the Company agrees
to indemnify the Trustee and Paying Agent from, and hold them harmless against,
any and all 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 counsel
fees and expenses) incurred by the Trustee or Paying Agent in the defense of any
claim or liability arising out of or in connection with the exercise or
performance of any of their powers, duties, responsibilities or obligations
under this Indenture except to the extent arising from their bad faith, willful
misconduct or negligence.

                                 IV. COVENANTS

4.01  PAYMENT OF SECURITIES.

      The Company shall pay all amounts due with respect to the Securities on
the dates and in the manner provided in the Securities and this Indenture, which
amounts, if payable hereunder in cash, shall be paid (A) in the case of a
Security that is in global form, by wire transfer of immediately available funds
to the account specified by the Holder hereof; or (B) in the case a Security is
held, other than global form, by a Holder who is the record holder of more than
five million dollars ($5,000,000) aggregate principal amount of Securities, by
wire transfer of immediately available funds to the account specified by such
Holder or, if no such account is specified, or if such Security is held, other
than in global form, by a Holder who is the record holder of five million
dollars ($5,000,000) or less in aggregate principal amount of Securities, by
mailing a check to such Holder's address shown in the register of the Registrar.
All such amounts shall be considered paid on the date due if the Paying Agent
holds (or, if the Company is acting as Paying Agent, the Company has segregated
and holds in trust in accordance with Section 2.04) on that date money
sufficient to pay the amount then due with respect to the Securities (unless
there shall be a Default in the payment of such amounts to the respective
Holder(s)).

      The Company shall pay interest on any overdue amount (including, to the
extent permitted by applicable law, overdue interest) at the rate borne by the
Securities.

4.02  MAINTENANCE OF OFFICE OR AGENCY.

      The Company will maintain, or cause to be maintained, in the Borough of
Manhattan, the City of New York, an office or agency (which may be an office of
the Trustee or an affiliate of the Trustee, Registrar or co-Registrar) where
Securities may be surrendered for registration of transfer or exchange, payment
or conversion and where notices and demands to or upon the Company in respect of
the Securities and this Indenture may be served. The Company will give prompt
written notice to the Trustee of the location, and any change in the location,
of such office or agency. If at any time the Company shall fail to maintain any
such required office or agency or shall fail to furnish the Trustee with the
address thereof, such presentations, surrenders, notices and demands may be made
or served at the Corporate Trust Office of the Trustee.


                                      -32-
<PAGE>
      The Company may also from time to time designate one or more other offices
or agencies where the Securities may be presented or surrendered for any or all
such purposes and may from time to time rescind such designations; provided,
however, that no such designation or rescission shall in any manner relieve the
Company of its obligation to maintain, or cause to be maintained, an office or
agency in the Borough of Manhattan, the City of New York for such purposes. The
Company will give prompt written notice to the Trustee of any such designation
or rescission and of any change in the location of any such other office or
agency.

      The Company hereby designates the Corporate Trust Office of the Trustee as
an agency of the Company in accordance with Section 2.03.

4.03  RULE 144A INFORMATION AND ANNUAL REPORTS.

      (A) At any time the Company is not subject to Sections 13 or 15(d) of the
Exchange Act, the Company shall, provided any of the Securities or shares of
Common Stock issuable upon conversion thereof shall, at such time, constitute
"restricted securities" within the meaning of Rule 144(a)(3) under the
Securities Act, promptly provide to the Trustee and shall, upon request, provide
to any Holder, beneficial owner or prospective purchaser of Securities or shares
of Common Stock issued upon conversion of any Securities, the information
required to be delivered pursuant to Rule 144A(d)(4) under the Securities Act to
facilitate the resale of such Securities or shares of Common Stock pursuant to
Rule 144A. The Company shall take such further action as any Holder or
beneficial holder of such Securities or shares of Common Stock may reasonably
request in writing to the extent required from time to time to enable such
Holder or beneficial holder to sell its Securities or shares of Common Stock in
accordance with Rule 144A, as such rule may be amended from time to time.

      (B) The Company shall, in accordance with TIA Section 314(a), deliver to
the Trustee, within thirty (30) calendar days after the Company files such
annual reports, information, documents and other reports with the SEC, copies of
the Company's annual reports (which shall contain audited financial statements
of the Company) and of the information, documents and other reports (or copies
of such portions of any of the foregoing as the SEC may by rules and regulations
prescribe) which the Company is required to file with the SEC pursuant to
Section 13 or Section 15(d) of the Exchange Act; provided, however, that the
Company shall not be required to deliver to the Trustee any material for which
the Company has sought and received confidential treatment by the SEC. In the
event the Company is at any time no longer subject to the reporting requirements
of Section 13 or Section 15(d) of the Exchange Act, the Company shall continue
to provide the Trustee and to each Holder, within thirty (30) calendar days
after the date the Company would have been required to file such reports with
the SEC, annual and quarterly consolidated financial statements substantially
equivalent to financial statements that would have been included in reports
filed with the SEC if the Company were subject to the reporting requirements of
Section 13 or Section 15(d) of the Exchange Act, including, with respect to
annual information only, a report thereon by the Company's certified independent
public accountants as such would be required in such reports filed with the SEC
and, in each case, together with a management's discussion and analysis of
financial condition and results of operations which would be so required. The
Company also shall comply with the other provisions of TIA Section 314(a).


                                      -33-
<PAGE>
4.04  COMPLIANCE CERTIFICATE.

      The Company shall deliver to the Trustee, within one hundred and twenty
(120) calendar days after the end of each fiscal year of the Company, an
Officer's Certificate stating whether or not the signatory to such Officer's
Certificate has actual knowledge of any Default or Event of Default by the
Company in performing any of its obligations under this Indenture or the
Securities. If such signatory does know of any such Default or Event of Default,
then such certificate shall describe such Default or Event of Default and its
status.

4.05  STAY, EXTENSION AND USURY LAWS.

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

4.06  CORPORATE EXISTENCE.

      Subject to Article V, the Company will do or cause to be done all things
necessary to preserve and keep in full force and effect its corporate existence
and the corporate existence of each of its Subsidiaries, in accordance with the
respective organizational documents of the Company and of each Subsidiary, and
the rights (charter and statutory), licenses and franchises of the Company and
its Subsidiaries; provided, however, that the Company shall not be required to
preserve any such right, license or franchise, or the corporate existence of any
Subsidiary, if in the good faith judgment of the Board of Directors (i) such
preservation or existence is not material to the conduct of business of the
Company and (ii) the loss of such right, license or franchise or the dissolution
of such Subsidiary does not have a material adverse impact on the Holders.

4.07  NOTICE OF DEFAULT.

      Upon the Company's becoming aware of the occurrence of any Default or
Event of Default, the Company shall give prompt written notice of such Default
or Event of Default, and any remedial action proposed to be taken, to the
Trustee.

4.08  FURTHER INSTRUMENTS AND ACTS.

      Upon the reasonable request of the Trustee, the Company shall execute and
deliver such further instruments and do such further acts as may be reasonably
necessary or proper to carry out more effectively the purposes of this
Indenture.


                                      -34-
<PAGE>
                                  V. SUCCESSORS

5.01 WHEN COMPANY MAY MERGE, ETC.

         The Company shall not consolidate with, or merge with or into, or sell,
transfer, lease, convey or otherwise dispose of all or substantially all of the
property or assets of the Company to, another person, whether in a single
transaction or series of related transactions, unless:

         (A) either:

                  (i) such transaction or series of related transactions shall
         be a merger or consolidation where the Company shall be the surviving
         corporation; or

                  (ii) the surviving, resulting or transferee person both (a) is
         a corporation organized and existing under the laws of the United
         States, any State thereof or the District of Columbia; and (b) assumes
         by supplemental indenture all the obligations of the Company under the
         Securities and this Indenture; and

         (B) immediately after giving effect to such transaction or series of
related transactions, no Default or Event of Default shall exist.

         The Company shall deliver to the Trustee prior to the consummation of
the proposed transaction an Officer's Certificate to the foregoing effect and an
Opinion of Counsel (which may rely upon (i) such Officer's Certificate as to the
absence of Defaults and Events of Default and (ii) a certificate of the
appropriate official of the jurisdiction in which any such surviving, resulting
or transferee person is organized certifying that such person is a corporation
organized in such jurisdiction) stating that the proposed transaction and such
supplemental indenture will, upon consummation of the proposed transaction,
comply with this Article V and with Articles IX and X and that all conditions
precedent herein provided to such transaction have been satisfied.

         For purposes of this Section 5.01, a Permitted Strategic Transaction
shall be deemed not to be a sale, transfer, lease, conveyance or other
disposition of all or substantially all of the property or assets of the Company
to another person.

5.02 SUCCESSOR SUBSTITUTED.

         Upon any consolidation, merger or any sale, transfer, lease, conveyance
or other disposition of all or substantially all of the property or assets of
the Company, the successor person formed by such consolidation or into which the
Company is merged or to which such sale, transfer, lease, conveyance or other
disposition is made shall succeed to, and, except in the case of a lease, be
substituted for, and may exercise every right and power of, and shall assume
every duty and obligation of, the Company under this Indenture with the same
effect as if such successor had been named as the Company herein. When the
successor assumes all obligations of the Company hereunder, except in the case
of a lease, all obligations of the predecessor shall terminate.

                                      -35-
<PAGE>
                           VI. DEFAULTS AND REMEDIES

6.01 EVENTS OF DEFAULT.

         An "EVENT OF DEFAULT" occurs if:

                  (i) the Company defaults in the payment of the principal of,
         or premium, if any, on, any Security when the same becomes due and
         payable, whether at maturity, upon Redemption, on an Option Purchase
         Date with respect to a Purchase at Holder's Option, on a Fundamental
         Change Repurchase Date with respect to a Repurchase Upon Fundamental
         Change or otherwise;

                  (ii) the Company defaults in the payment of an installment of
         interest or additional interest on any Security when due, if such
         failure continues for thirty (30) days after the date when due;

                  (iii) the Company fails to satisfy its conversion obligations
         upon exercise of a Holder's conversion rights pursuant hereto;

                  (iv) the Company fails to timely provide a Fundamental Change
         Notice, or an Option Purchase Notice, as required by the provisions of
         this Indenture;

                  (v) the Company fails to comply with any other term, covenant
         or agreement set forth in the Securities or this Indenture and such
         failure continues for the period, and after the notice, specified
         below;

                  (vi) the Company or any of its Subsidiaries defaults in the
         payment when due, after the expiration of any applicable grace period,
         of principal of, or premium, if any, or interest on, Indebtedness of
         the Company or any Subsidiary for money borrowed, in the aggregate
         principal amount then outstanding of ten million dollars ($10,000,000)
         or more, or the acceleration of Indebtedness of the Company or any of
         its Subsidiaries for money borrowed in such aggregate principal amount
         or more so that it becomes due and payable prior to the date on which
         it would otherwise become due and payable and such default is not cured
         or waived, or such acceleration is not rescinded, within sixty (60)
         days after notice to the Company by the Trustee or to the Company and
         the Trustee by Holders of at least twenty five percent (25%) in the
         aggregate principal amount of the Securities then outstanding, each in
         accordance with this Indenture;

                  (vii) the Company or any of its Significant Subsidiaries (or,
         within any period of one (1) year, each of two (2) or more Subsidiaries
         that, in the aggregate, would constitute a Significant Subsidiary of
         the Company), pursuant to, or within the meaning of, any Bankruptcy
         Law, insolvency law, or other similar law now or hereafter in effect or
         otherwise, either:

                           (A) commences a voluntary case,

                                      -36-
<PAGE>
                           (B) consents to the entry of an order for relief
                  against it in an involuntary case,

                           (C) consents to the appointment of a Custodian of it
                  or for all or substantially all of its property, or

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

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

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

                           (B) appoints a Custodian of the Company or any of its
                  Significant Subsidiaries for all or substantially all of the
                  property of the Company or any such Significant Subsidiary, as
                  the case may be, or

                           (C) orders the winding up or liquidation of the
                  Company or any of its Significant Subsidiaries,

           and, in the case of each of the foregoing clauses (A), (B) and (C) of
           this Section 6.01(viii), the order or decree remains unstayed and in
           effect for at least ninety (90) consecutive days (provided, that
           there shall be deemed to occur an Event of Default pursuant to this
           Section 6.01(viii) if, during any single period of (90) consecutive
           days, there shall have remained unstayed any one or more such orders
           or decrees with respect to two (2) or more Subsidiaries that, in the
           aggregate, would constitute a Significant Subsidiary of the Company).

         The term "BANKRUPTCY LAW" means Title 11, U.S. Code or any similar
Federal or U.S. State law for the relief of debtors. The term "CUSTODIAN" means
any receiver, trustee, assignee, liquidator or similar official under any
Bankruptcy Law.

         A Default under clause (v) above is not an Event of Default until (I)
the Trustee notifies the Company, or the Holders of at least twenty five percent
(25%) in aggregate principal amount of the Securities then outstanding notify
the Company and the Trustee, of the Default and (II) the Default is not cured
within sixty (60) days after receipt of such notice. Such notice must specify
the Default, demand that it be remedied and state that the notice is a "NOTICE
OF DEFAULT." If the Holders of at least twenty five percent (25%) in aggregate
principal amount of the outstanding Securities request the Trustee to give such
notice on their behalf, the Trustee shall do so. When a Default is cured, it
ceases to exist for every purpose under this Indenture.

6.02 ACCELERATION.

         If an Event of Default (excluding an Event of Default specified in
Section 6.01(vii) or (viii) with respect to the Company (but including an Event
of Default specified in Section 6.01(vii) or (viii) solely with respect to a
Significant Subsidiary of the Company or any group of

                                      -37-
<PAGE>
Subsidiaries that in the aggregate would constitute a Significant Subsidiary of
the Company)) occurs and is continuing, the Trustee by notice to the Company, or
the Holders of at least twenty five percent (25%) in aggregate principal amount
of the Securities then outstanding by notice to the Company and the Trustee, may
declare the Securities to be immediately due and payable in full. Upon such
declaration, the principal of, and any premium and accrued and unpaid interest
(including any additional interest) on, all Securities shall be due and payable
immediately. If an Event of Default specified in Section 6.01(vii) or (viii)
with respect to the Company (excluding, for purposes of this sentence, an Event
of Default specified in Section 6.01(vii) or (viii) solely with respect to a
Significant Subsidiary of the Company or any group of Subsidiaries that in the
aggregate would constitute a Significant Subsidiary of the Company) occurs, the
principal of, and any premium and accrued and unpaid interest (including any
additional interest) on, all the Securities shall ipso facto become and be
immediately due and payable without any declaration or other act on the part of
the Trustee or any Holder. The Holders of a majority in aggregate principal
amount of the Securities then outstanding by written notice to the Trustee may
rescind or annul an acceleration and its consequences if (A) the rescission
would not conflict with any governmental or court order or decree, (B) all
existing Events of Default, except the nonpayment of principal, premium, if any,
or interest that has become due solely because of the acceleration, have been
cured or waived and (C) all amounts due to the Trustee under Section 7.07 have
been paid.

6.03 OTHER REMEDIES.

         Notwithstanding any other provision of this Indenture, if an Event of
Default occurs and is continuing, the Trustee may pursue any available remedy by
proceeding at law or in equity to collect the payment of amounts due with
respect to the Securities or to enforce the performance of any provision of the
Securities or this Indenture.

         The Trustee may maintain a proceeding even if it does not possess any
of the Securities or does not produce any of them in the proceeding. A delay or
omission by the Trustee or any Holder in exercising any right or remedy accruing
upon an Event of Default shall not impair the right or remedy or constitute a
waiver of or acquiescence in the Event of Default. All remedies are cumulative.

6.04 WAIVER OF PAST DEFAULTS.

         Subject to Sections 6.07 and 9.02, the Holders of a majority in
aggregate principal amount of the Securities then outstanding may, by notice to
the Trustee, waive any past Default or Event of Default and its consequences,
other than (A) a Default or Event of Default in the payment of the principal of,
or premium, if any, or interest or additional interest on, any Security, or in
the payment of the Redemption Price, the Option Purchase Price or the
Fundamental Change Repurchase Price (or accrued and unpaid interest, if any,
payable as herein provided, upon Redemption, Purchase at Holder's Option or
Repurchase Upon Fundamental Change), (B) a Default or Event of Default arising
from a failure by the Company to convert any Securities into shares of Common
Stock in accordance with this Indenture or (C) any Default or Event of Default
in respect of any provision of this Indenture or the Securities which, under
Section 9.02, cannot be modified or amended without the consent of the Holder of
each outstanding Security affected. When a Default or an Event of Default is
waived, it is cured and ceases to exist for

                                      -38-
<PAGE>
every purpose of this indenture; provided, however, that no waiver of a Default
or Event of Default shall extend to any subsequent or other Default or Event of
Default or impair any consequent right. This Section 6.04 shall be in lieu of
TIA Section 316(a)(1)(B), and, as permitted by the TIA, TIA Section 316(a)(1)(B)
is hereby expressly excluded from this Indenture.

6.05 CONTROL BY MAJORITY.

         The Holders of a majority in aggregate principal amount of the
Securities then outstanding may 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 it. However, the Trustee may refuse to follow any
direction that conflicts with law or this Indenture, is unduly prejudicial to
the rights of other Holders or would involve the Trustee in personal liability
unless the Trustee is offered indemnity reasonably satisfactory to it; provided,
that the Trustee may take any other action deemed proper by the Trustee which is
not inconsistent with such direction. This Section 6.05 shall be in lieu of TIA
Section 316(a)(1)(A), and, as permitted by the TIA, TIA Section 316(a)(1)(A) is
hereby expressly excluded from this Indenture.

6.06 LIMITATION ON SUITS.

         Except as provided in Section 6.07, a Securityholder may not institute
any proceeding under this Indenture, or for the appointment of a receiver or a
trustee, or for any other remedy under this Indenture unless:

                  (i) the Holder gives to the Trustee written notice of a
         continuing Event of Default;

                  (ii) the Holders of at least twenty five percent (25%) in
         aggregate principal amount of the Securities then outstanding make a
         written request to the Trustee to pursue the remedy;

                  (iii) such Holder or Holders offer and, if requested, provide
         to the Trustee indemnity reasonably satisfactory to the Trustee against
         any loss, liability or expense to or of the Trustee in connection with
         pursuing such remedy;

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

                  (v) during such sixty (60) day period, the Holders of a
         majority in aggregate principal amount of the Securities then
         outstanding do not give the Trustee a direction inconsistent with the
         request.

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

6.07 RIGHTS OF HOLDERS TO RECEIVE PAYMENT.

         Notwithstanding any other provision of this Indenture, the right of any
Holder to receive payment of all amounts due with respect to the Securities, on
or after the respective due dates as

                                      -39-
<PAGE>
provided herein, or to bring suit for the enforcement of any such payment on or
after such respective dates, shall not be impaired or affected without the
consent of the Holder.

         Notwithstanding any other provision of this Indenture, the right of any
Holder to bring suit for the enforcement of the right to convert the Security in
accordance with this Indenture shall not be impaired or affected without the
consent of the Holder.

6.08 COLLECTION SUIT BY TRUSTEE.

         If an Event of Default specified in Section 6.01(i) or (ii) occurs and
is continuing, the Trustee may recover judgment in its own name and as trustee
of an express trust against the Company for the whole amount due with respect to
the Securities, including any unpaid and accrued interest.

6.09 TRUSTEE MAY FILE PROOFS OF CLAIM.

         The Trustee may file such proofs of claim and other papers or documents
as may be necessary or advisable in order to have the claims of the Trustee, any
predecessor Trustee and the Securityholders allowed in any judicial proceedings
relative to the Company or its creditors or properties.

         The Trustee may collect and receive any moneys or other property
payable or deliverable on any such claims and to distribute the same, and any
custodian, receiver, assignee, trustee, liquidator, sequestrator or similar
official in any judicial proceeding is hereby authorized by each Holder to make
such payments to the Trustee and, in the event that the Trustee shall consent to
the making of such payments directly to the Holders, to pay the Trustee any
amount due it for the reasonable compensation, expenses, disbursements and
advances of the Trustee, its agents and counsel, and any other amounts due the
Trustee under Section 7.07.

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

6.10 PRIORITIES.

         If the Trustee collects any money pursuant to this Article VI, it shall
pay out the money in the following order:

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

         Second:  to Securityholders for all amounts due and unpaid on the
                  Securities, without preference or priority of any kind,
                  according to the amounts due and payable on the Securities;
                  and

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

                                      -40-
<PAGE>
         The Trustee, upon prior written notice to the Company, may fix a record
date and payment date for any payment by it to Securityholders pursuant to this
Section 6.10. At least fifteen (15) days before each such record date, the
Trustee shall mail to each Holder and the Company a written notice that states
such record date and payment date and the amount of such payment.

6.11 UNDERTAKING FOR COSTS.

         In any suit for the enforcement of any right or remedy under this
Indenture or in any suit against the Trustee for any action taken or omitted by
it as Trustee, a court in its discretion may require the filing by any party
litigant in the suit other than the Trustee of an undertaking to pay the costs
of the suit, and the court in its discretion may assess reasonable costs,
including reasonable attorneys' fees, against any party litigant in the suit,
having due regard to the merits and good faith of the claims or defenses made by
the party litigant. This Section 6.11 does not apply to a suit by the Trustee, a
suit by a Holder pursuant to Section 6.07 or a suit by Holders of more than ten
percent (10%) in aggregate principal amount of the outstanding Securities.

                                  VII. TRUSTEE

7.01 DUTIES OF TRUSTEE.

         (A) If 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 person
would exercise or use under the circumstances in the conduct of his or her own
affairs.

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

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

                  (ii) in the absence of bad faith, willful misconduct or
         negligence on its part, the Trustee may conclusively rely, as to the
         truth of the statements and the correctness of the opinions expressed
         therein, upon certificates or opinions furnished to the Trustee and
         conforming to the requirements of this Indenture; but in the case of
         any such certificates or opinions which by any provision hereof are
         specifically required to be furnished to the Trustee, the Trustee shall
         examine the certificates and opinions to determine whether or not they
         conform to the requirements of this Indenture (but need not confirm or
         investigate the accuracy of mathematical calculations or other facts
         stated therein).

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

                                      -41-
<PAGE>
                  (i) the Trustee shall not be liable for any error of judgment
         made in good faith by a Responsible Officer, unless it is proved that
         the Trustee was negligent in ascertaining the pertinent facts; and

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

         (D) Every provision of this Indenture that in any way relates to the
Trustee is subject to the provisions of this Section 7.01.

         (E) The Trustee shall not be liable for interest on any money received
by it except as the Trustee may agree in writing with the Company. Money held in
trust by the Trustee shall be segregated from other funds, as directed by the
Company or as required by law, and shall be invested by the Trustee pursuant to
the written instructions of the Company reasonably satisfactory to the Trustee;
provided, however, that the Trustee shall have no liability hereunder with
respect to any such investment, other than by reason of the willful misconduct
or negligence of the Trustee; provided further, that in no event shall the
Trustee be liable for special, punitive, indirect, consequential or incidental
loss or damage of any kind whatsoever (including but not limited to lost
profits) with respect to such investments, even if the Trustee has been advised
of the likelihood of such loss or damage; provided further, that nothing in this
Section 7.01(E) shall affect the Company's obligations to make all payments due
under the Securities.

7.02 RIGHTS OF TRUSTEE.

         (A) Subject to Section 7.01, the Trustee may conclusively rely on any
document believed by it to be genuine and to have been signed or presented by
the proper person. The Trustee need not investigate any fact or matter stated in
the document; if, however, the Trustee shall determine to make such further
inquiry or investigation, it shall be entitled during normal business hours of
the Company to examine the relevant books, records and premises of the Company,
personally or by agent or attorney upon reasonable prior notice.

         (B) Before the Trustee acts or refrains from acting, it may require an
Officer's Certificate and/or an Opinion of Counsel which conforms to the
requirements of Section 11.05. The Trustee shall not be liable for any action it
takes or omits to take in good faith in reliance on such Officer's Certificate
or Opinion of Counsel.

         (C) 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.

         (D) The Trustee may consult with counsel (such counsel to be reasonably
acceptable to the Company), 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 may act through agents or attorneys and shall not be
responsible for the misconduct or negligence of any agent or attorney appointed
with due care.

                                      -42-
<PAGE>
         (F) The Trustee shall not be liable for any action it takes or omits to
take in good faith which it believes to be authorized or within its discretion,
rights or powers conferred upon it by this Indenture.

         (G) Except with respect to Section 6.01, the Trustee shall have no duty
to inquire as to the performance of the Company with respect to the covenants
contained in Article IV. In addition, the Trustee shall not be deemed to have
knowledge of an Event of Default except (i) any Default or Event of Default
occurring pursuant to Sections 6.01(i) or (ii) or (ii) any Default or Event of
Default of which a Responsible Officer of the Trustee shall have received
written notification or obtained actual knowledge. Delivery of reports,
information and documents to the Trustee under Article IV (other than Sections
4.04 and 4.07) is for informational purposes only and the Trustee's receipt of
the foregoing shall not constitute constructive notice of any information
contained therein or determinable from information contained therein, including
the Company's compliance with any of its covenants hereunder (as to which the
Trustee is entitled to rely on Officer's Certificates).

         (H) Subject to Section 7.01(A), the Trustee shall be under no
obligation to exercise any of the rights or powers vested by this Indenture at
the request or direction of any of the Holders pursuant to this Indenture unless
such Holders shall have offered to the Trustee security or indemnity reasonably
satisfactory to the Trustee against the costs, expenses and liabilities which
might be incurred by it in compliance with such request or direction.

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

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

7.03 INDIVIDUAL RIGHTS OF TRUSTEE.

         The Trustee in its individual or any other capacity may become the
owner or pledgee of Securities and may otherwise deal with the Company or any of
its Affiliates with the same rights the Trustee would have if it were not
Trustee. Any Security Agent may do the same with like rights. The Trustee,
however, must comply with Sections 7.10 and 7.11.

7.04 TRUSTEE'S DISCLAIMER.

         The Trustee makes no representation as to the validity or adequacy of
this Indenture or the Securities; the Trustee shall not be accountable for the
Company's use of the proceeds from the Securities, for the Company's performance
hereunder or for the Company's representations and warranties contained herein;
and the Trustee shall not be responsible for any statement in the Securities
(other than the Trustee's certificate of authentication), the Shelf Registration
Statement (other than any statement of eligibility executed by the Trustee and
filed with the

                                      -43-
<PAGE>
Shelf Registration Statement pursuant to Item 601(b)(25) of Regulation S-K
promulgated under the Securities Act) or any other offering document related to
the Securities.

7.05 NOTICE OF DEFAULTS.

         If a Default or Event of Default occurs and is continuing as to which
the Trustee has received notice pursuant to the provisions of this Indenture, or
as to which a Responsible Officer of the Trustee shall have actual knowledge,
then the Trustee shall mail to each Holder a notice of the Default or Event of
Default within thirty (30) days after the Trustee has received such notice or
after such Responsible Officer shall have acquired such actual knowledge,
whichever is earlier, unless such Default or Event of Default has been cured or
waived; provided, however, that, except in the case of a Default or Event of
Default in payment of any amounts due with respect to any Security, the Trustee
may withhold such notice if, and so long as it in good faith determines that,
withholding such notice is in the best interests of Holders.

7.06 REPORTS BY TRUSTEE TO HOLDERS.

         Within sixty (60) days after each May 15, beginning with May 15, 2005,
the Trustee shall mail to each Securityholder, pursuant to Section 11.02, if
required by TIA Section 313(a) a brief report dated as of such May 15 that
complies with TIA Section 313.

         A copy of each report at the time of its mailing to Securityholders
shall be mailed by first class mail to the Company and filed by the Trustee with
the SEC and each stock exchange, if any, on which the Securities are listed. The
Company shall promptly notify the Trustee of the listing or delisting of the
Securities on or from any stock exchange.

7.07 COMPENSATION AND INDEMNITY.

         The Company shall pay to the Trustee from time to time such
compensation for its services as shall be agreed upon in writing. The Trustee's
compensation shall not be limited by any law on compensation of a trustee of an
express trust. The Company shall reimburse the Trustee upon request for all
reasonable out-of-pocket expenses incurred by it pursuant to, and in accordance
with, any provision hereof. Such expenses shall include the reasonable
compensation and out-of-pocket expenses of the Trustee's agents and counsel.

         The Company shall indemnify the Trustee against any and all loss,
liability, damage, claim or expense (including the reasonable fees and expenses
of counsel and taxes other than those based upon the income of the Trustee)
incurred by it in connection with the acceptance or administration of this trust
and the performance of its duties hereunder, including the reasonable costs and
expenses of defending itself against any claim (whether asserted by the Company,
any Holder or any other Person) or liability in connection with the exercise or
performance of any of its powers and duties hereunder. The Company need not pay
for any settlement made without its consent. The Trustee shall notify the
Company promptly of any claim for which it may seek indemnification. The Company
need not reimburse any expense or indemnify against any loss or liability
incurred by the Trustee through the Trustee's negligence, bad faith or willful
misconduct.

                                      -44-
<PAGE>
         To secure the Company's payment obligations in this Section 7.07, the
Trustee shall have a lien prior to the Securities on all money or property held
or collected by the Trustee, except that held in trust to pay amounts due on
particular Securities.

         The indemnity obligations of the Company with respect to the Trustee
provided for in this Section 7.07 shall survive any resignation or removal of
the Trustee.

         When the Trustee incurs expenses or renders services after an Event of
Default specified in Section 6.01(vii) or (viii) occurs, the expenses and the
compensation for the services are intended to constitute expenses of
administration under any Bankruptcy Law.

7.08 REPLACEMENT OF TRUSTEE.

         A resignation or removal of the Trustee and appointment of a successor
Trustee shall become effective only upon the successor Trustee's acceptance of
appointment as provided in this Section 7.08.

         The Trustee may resign by so notifying the Company in writing thirty
(30) Business Days prior to such resignation. The Holders of a majority in
aggregate principal amount of the Securities then outstanding may remove the
Trustee by so notifying the Trustee and the Company in writing and may appoint a
successor Trustee with the Company's consent. The Company may remove the Trustee
if:

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

                  (ii) the Trustee is adjudged a bankrupt or an insolvent;

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

                  (iv) the Trustee becomes incapable of acting.

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

         If a successor Trustee does not take office within thirty (30) days
after the retiring Trustee resigns or is removed, the retiring Trustee (at the
Company's expense), the Company or the Holders of at least ten percent (10%) in
aggregate principal amount of the outstanding Securities may petition any court
of competent jurisdiction for the appointment of a successor Trustee.

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

         A successor Trustee shall deliver a written acceptance of its
appointment to the retiring Trustee and to the Company. Thereupon the
resignation or removal of the retiring Trustee shall become effective, and the
successor Trustee shall have all the rights, powers and duties of the

                                      -45-
<PAGE>
Trustee under this Indenture. The successor Trustee shall mail a notice of its
succession to Securityholders. The retiring Trustee shall promptly transfer all
property held by it as Trustee to the successor Trustee, subject to the lien
provided for in Section 7.07.

7.09 SUCCESSOR TRUSTEE BY MERGER, ETC.

         If the Trustee consolidates with, merges or converts into, or transfers
all or substantially all of its corporate trust business to, another
corporation, the successor corporation without any further act shall be the
successor Trustee, if such successor corporation is otherwise eligible
hereunder.

7.10 ELIGIBILITY; DISQUALIFICATION.

         There shall at all times be a Trustee hereunder that is a corporation
organized and doing business under the laws of the United States of America or
of any state thereof, which Trustee (A) is authorized under such laws to
exercise corporate trust powers, (B) is subject to supervision or examination by
federal, state or District of Columbia authorities and (C) has a combined
capital and surplus of at least $100 million as set forth in its most recent
published annual report of condition. The Trustee shall comply with TIA Section
310(b). Nothing in this Indenture shall prevent the Trustee from filing with the
SEC the application referred to in the penultimate paragraph of TIA Section
310(b). This Indenture shall at all times have a Trustee that satisfies the
requirements of TIA Section 310(a)(5).

7.11 PREFERENTIAL COLLECTION OF CLAIMS AGAINST COMPANY.

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

                          VIII. DISCHARGE OF INDENTURE

8.01 TERMINATION OF THE OBLIGATIONS OF THE COMPANY.

         This Indenture shall cease to be of further effect if (a) either (i)
all outstanding Securities (other than Securities replaced pursuant to Section
2.07 hereof) have been delivered to the Trustee for cancellation or (ii) all
outstanding Securities have become due and payable at their scheduled maturity
or upon Purchase at Holder's Option, Redemption or Repurchase Upon Fundamental
Change, and in either case the Company irrevocably deposits, prior to the
applicable due date, with the Trustee or the Paying Agent (if the Paying Agent
is not the Company or any of its Affiliates) cash, and, if applicable as herein
provided and in accordance herewith, such other consideration, sufficient to pay
all amounts due and owing on all outstanding Securities (other than Securities
replaced pursuant to Section 2.07 hereof) on the Maturity Date or an Option
Purchase Date, Redemption Date or Fundamental Change Repurchase Date, as the
case may be; (b) the Company pays to the Trustee all other sums payable
hereunder by the Company; (c) no Default or Event of Default with respect to the
Securities shall exist on the date of such deposit; (d) such deposit will not
result in a breach or violation of, or constitute a Default or Event of Default
under, this Indenture or any other

                                      -46-
<PAGE>
agreement or instrument to which the Company is a party or by which it is bound;
and (e) the Company has delivered to the Trustee an Officer's Certificate and an
Opinion of Counsel, each stating that all conditions precedent provided for
herein relating to the satisfaction and discharge of this Indenture have been
complied with; provided, however, that Sections 2.02, 2.03, 2.04, 2.05, 2.06,
2.07, 2.08, 2.15, 2.16, 2.17, 3.05, 3.08, 3.09, 4.01, 4.02, 4.05, 7.07 and 7.08
and Articles VIII and X shall survive any discharge of this Indenture until such
time as the Securities have been paid in full and there are no Securities
outstanding.

8.02 APPLICATION OF TRUST MONEY.

         The Trustee shall hold in trust all money and other consideration
deposited with it pursuant to Section 8.01 and shall apply such deposited money
and other consideration through the Paying Agent and in accordance with this
Indenture to the payment of the amounts due on the Securities.

8.03 REPAYMENT TO COMPANY.

         The Trustee and the Paying Agent shall promptly notify the Company of,
and pay to the Company upon the written request of the Company, any excess money
held by them at any time. The Trustee or the Paying Agent, as the case may be,
shall provide written notice to the Company of any money that has been held by
it and has, for a period of two (2) years, remained unclaimed for the payment of
the principal of, or any accrued and unpaid interest on, the Securities. The
Trustee and the Paying Agent shall pay to the Company, upon the written request
of the Company, any money held by them for the payment of the principal of,
premium, if any, or any accrued and unpaid interest or additional interest on,
the notes that remains unclaimed for two (2) years; provided, however, that the
Trustee or such Paying Agent, before being required to make any such repayment,
may, at the expense of the Company, cause to be published once in a newspaper of
general circulation in the City of New York or cause to be mailed to each
Holder, in accordance with Section 11.02, notice stating that such money remains
unclaimed and that, after a date specified therein, which shall not be less than
thirty (30) days from the date of such publication or mailing, any unclaimed
balance of such money then remaining will be repaid to the Company. After
payment to the Company, Securityholders entitled to the money must look to the
Company for payment as general creditors, subject to applicable law, and all
liability of the Trustee and the Paying Agent with respect to such money and
payment shall, subject to applicable law, cease.

8.04 REINSTATEMENT.

         If the Trustee or Paying Agent is unable to apply any money or other
consideration in accordance with Sections 8.01 and 8.02 by reason of any legal
proceeding or by reason of any order or judgment of any court or governmental
authority enjoining, restraining or otherwise prohibiting such application, the
obligations of the Company under this Indenture and the Securities shall be
revived and reinstated as though no deposit had occurred pursuant to Sections
8.01 and 8.02 until such time as the Trustee or Paying Agent is permitted to
apply all such money or other consideration in accordance with Sections 8.01 and
8.02; provided, however, that if the Company has made any payment of amounts due
with respect to any Securities because of the reinstatement of its obligations,
then the Company shall be subrogated to the rights of the

                                      -47-
<PAGE>
Holders of such Securities to receive such payment from the money held by the
Trustee or Paying Agent.

                                 IX. AMENDMENTS

9.01 WITHOUT CONSENT OF HOLDERS.

         The Company, with the consent of the Trustee, may amend or supplement
this Indenture or the Securities without notice to or the consent of any
Securityholder:

                  (i) to comply with Sections 5.01 and 10.12 and, in accordance
         with Section 10.15(F), to give effect to an election, pursuant to such
         Section 10.15(F), by the Company to make an Acquirer Stock Conversion
         Right Adjustment with respect to a Public Acquirer Fundamental Change;

                  (ii) to make any changes or modifications to this Indenture
         necessary in connection with the registration of the public offer and
         sale of the Securities under the Securities Act pursuant to the
         Registration Rights Agreement or the qualification of this Indenture
         under the TIA;

                  (iii) to secure the obligations of the Company in respect of
         the Securities;

                  (iv) to add to the covenants of the Company described in this
         Indenture for the benefit of Securityholders or to surrender any right
         or power conferred upon the Company;

                  (v) to make provisions with respect to adjustments to the
         Conversion Rate as required by this Indenture or to increase the
         Conversion Rate in accordance with this Indenture;

                  (vi) to add additional events which shall constitute an Event
         of Default hereunder; and

                  (vii) to provide for a successor Trustee in accordance
         herewith.

         In addition, the Company and the Trustee may enter into a supplemental
indenture without the consent of Holders of the Securities to cure any
ambiguity, defect, omission or inconsistency in this Indenture in a manner that
does not individually or in the aggregate adversely affect the rights of any
Holder in any material respect; provided, that the Trustee shall be entitled to
receive and conclusively rely upon an Opinion of Counsel as to whether any such
cure does not individually or in the aggregate adversely affect the rights of
any Holder in any material respect.

9.02 WITH CONSENT OF HOLDERS.

         The Company, with the consent of the Trustee, may amend or supplement
this Indenture or the Securities without notice to any Securityholder but with
the written consent of the Holders

                                      -48-
<PAGE>

of at least a majority in aggregate principal amount of the outstanding
Securities. Subject to Sections 6.04 and 6.07, the Holders of a majority in
aggregate principal amount of the outstanding Securities may, by notice to the
Trustee, waive compliance by the Company with any provision of this Indenture or
the Securities without notice to any other Securityholder. Notwithstanding
anything herein to the contrary, without the consent of each Holder of each
outstanding Security affected, an amendment, supplement or waiver, including a
waiver pursuant to Section 6.04, may not:

                           (a) change the stated maturity of the principal of,
                  or the payment date of any installment of interest or any
                  premium on, any Security;

                           (b) reduce the principal amount of, or any premium,
                  interest or additional interest on, any Security;

                           (c) change the place or currency of payment of
                  principal of, or any premium, interest or additional interest
                  on, any Security;

                           (d) impair the right to institute suit for the
                  enforcement of any payment on, or with respect to, any
                  Security;

                           (e) modify, in a manner adverse to Holders, the
                  provisions with respect to the right of Holders pursuant to
                  Article III to require the Company to purchase Securities on
                  an Option Purchase Date or to repurchase Securities upon the
                  occurrence of a Fundamental Change;

                           (f) modify the provisions of Section 2.18 in a manner
                  adverse to Holders;

                           (g) adversely affect the right of Holders to convert
                  Securities in accordance with Article X;

                           (h) reduce the percentage of the aggregate principal
                  amount of the outstanding Securities whose Holders must
                  consent to a modification to or amendment of any provision of
                  this Indenture or the Securities;

                           (i) reduce the percentage of the aggregate principal
                  amount of the outstanding Securities whose Holders must
                  consent to a waiver of compliance with any provision of this
                  Indenture or the Securities or a waiver of any Default or
                  Event of Default; or

                           (j) modify the provisions of this Indenture with
                  respect to modification and waiver (including waiver of a
                  Default or an Event of Default), except to increase the
                  percentage required for modification or waiver or to provide
                  for consent of each affected Holder.

         Promptly after an amendment, supplement or waiver under Section 9.01 or
this Section 9.02 becomes effective, the Company shall mail, or cause to be
mailed, to Securityholders a notice briefly describing such amendment,
supplement or waiver. Any failure of the Company to

                                      -49-
<PAGE>
mail such notice shall not in any way impair or affect the validity of such
amendment, supplement or waiver.

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

9.03 COMPLIANCE WITH TRUST INDENTURE ACT.

         Every amendment, waiver or supplement to this Indenture or the
Securities shall comply with the TIA as then in effect.

9.04 REVOCATION AND EFFECT OF CONSENTS.

         If the Company shall solicit from the Holders a consent to any
amendment or supplement to the Indenture or any waiver hereunder, in each case
in accordance herewith, the Company may, but shall not be obligated to,
establish, by Board Resolution and delivery of an Officer's Certificate to the
Trustee, a record date for the purpose of determining the Holders of record
entitled to give such consent; provided, however, that (i) such record date
shall not be more than fifteen (15) days prior to the first solicitation of such
consent, and (ii) at least fifteen (15) days prior to such record date, the
Company shall, in accordance with Section 11.02, mail, or cause to be mailed, by
first class mail a notice of such record date to each Holder and shall publicly
disseminate a press release through a reputable national newswire service,
disclosing such record date. If a record date is so fixed in accordance
herewith, then (A) only the Holders of record at 5:00 p.m., New York City time,
on such record date shall be deemed to be Holders for the purposes of
determining whether Holders of the requisite proportion of outstanding
Securities have consented to such amendment, supplement or waiver, and for that
purpose the outstanding Securities shall be computed as of such record date; and
(B) those persons who were Holders as of 5:00 p.m., New York City time, on such
record date (or their duly designated proxies), and only those persons, shall be
entitled to revoke any consent previously given, whether or not any such person
continues to be a Holder after such record date; provided, however, that no such
consent by the Holders on such record date shall be effective unless the
applicable amendment, supplement or waiver shall become effective pursuant to
the provisions hereof no later than six (6) months after such record date.

         Until an amendment, supplement or waiver becomes effective, a consent
to it by a Holder is a continuing consent by the Holder and every subsequent
Holder of a Security or portion of a Security that evidences the same debt as
the consenting Holder's Security, even if notation of the consent is not made on
any Security. However, any such Holder or, except as provided in the immediately
preceding paragraph, subsequent Holder may revoke the consent as to its Security
or portion of a Security if the Trustee receives the notice of revocation before
the date the amendment, supplement or waiver becomes effective. An amendment,
supplement or waiver becomes effective in accordance with its terms and
thereafter binds every Holder.

         After an amendment, supplement or waiver becomes effective with respect
to the Securities, it shall bind every Holder (including subsequent Holders)
unless such amendment, supplement or waiver makes a change that requires,
pursuant to Section 9.02, the consent of each

                                      -50-
<PAGE>
Holder affected. In that case, the amendment, supplement or waiver shall bind
each Holder of a Security who has consented to it and, provided that notice of
such amendment, supplement or waiver is reflected on a Security that evidences
the same debt as the consenting Holder's Security, every subsequent Holder of a
Security or portion of a Security that evidences the same debt as the consenting
Holder's Security.

         Nothing in this Section 9.04 shall impair the Company's rights pursuant
Section 9.01(i) to amend this Indenture or the Securities without the consent of
any Securityholder in the manner set forth in, and permitted by, such Section
9.01(i).

9.05 NOTATION ON OR EXCHANGE OF SECURITIES.

         If an amendment, supplement or waiver changes the terms of a Security,
the Trustee may require the Holder of the Security to deliver it to the Trustee.
The Trustee may place an appropriate notation on the Security as directed and
prepared by the Company about the changed terms and return it to the Holder.
Alternatively, if the Company so determines, the Company in exchange for the
Security shall issue and the Trustee shall authenticate a new Security that
reflects the changed terms.

9.06 TRUSTEE PROTECTED.

         The Trustee shall sign any amendment, supplemental indenture or waiver
authorized pursuant to this Article IX; provided, however, that the Trustee need
not sign any amendment, supplement or waiver authorized pursuant to this Article
IX that adversely affects the Trustee's rights, duties, liabilities or
immunities. The Trustee shall be entitled to receive and conclusively rely upon
an Opinion of Counsel as to legal matters and an Officer's Certificate as to
factual matters that any supplemental indenture, amendment or waiver is
permitted or authorized pursuant to this Indenture.

9.07 EFFECT OF SUPPLEMENTAL INDENTURES.

         Upon the due execution and delivery of any supplemental indenture in
accordance with this Article IX, this Indenture shall be modified in accordance
therewith, and such supplemental indenture shall form a part of this Indenture
for all purposes, and, except as set forth in Sections 9.02 and 9.04, every
Holder of Securities shall be bound thereby.

                                 X. CONVERSION

10.01 CONVERSION PRIVILEGE; RESTRICTIVE LEGENDS.

         (A) Subject to the provisions of Article III, the Securities shall be
convertible into shares of Common Stock in accordance with this Article X at any
time prior to stated maturity, upon the satisfaction of the conditions set forth
in the second paragraph of paragraph 10 of the Securities.

                                      -51-
<PAGE>
         (B) The initial Conversion Rate shall be 92.9023 shares of Common Stock
per $1,000 principal amount of Securities. The Conversion Rate shall be subject
to adjustment in accordance with Sections 10.06 through 10.15.

         (C) A Holder may convert a portion of the principal amount of a
Security if the portion is $1,000 principal amount or an integral multiple of
$1,000 principal amount. Provisions of this Indenture that apply to conversion
of all of a Security also apply to conversion of a portion of it.

         (D) Any shares of Common Stock that are issued upon conversion of a
Security shall bear the Private Placement Legend until the earlier of the second
anniversary of the later of the Issue Date and the last date on which the
Company or any Affiliate was the owner of such shares or the Security (or any
predecessor security) from which such shares were converted (or such shorter
period of time as permitted by Rule 144(k) under the Securities Act or any
successor provision thereunder) (or such longer period of time as may be
required under the Securities Act or applicable state securities laws, as set
forth in an Opinion of Counsel, unless otherwise agreed by the Company and the
Holder thereof).

10.02 CONVERSION PROCEDURE.

         (A) To convert a Security, a Holder must satisfy the requirements of
paragraph 10 of the Securities. As soon as practicable following the date (the
"CONVERSION DATE") on which the Holder satisfies all those requirements, the
Company shall deliver to the Holder through the Conversion Agent a certificate
for the number of full shares of Common Stock issuable upon the conversion, as
provided in paragraph 10 of the Securities, and a check for the amount of cash
payable in lieu of any fractional share; provided, however, that any Make-Whole
Consideration payable pursuant to Section 10.15 shall be delivered by the
Company within the time period specified in Section 10.15(D). Immediately before
the close of business on the Conversion Date, and thereafter, the person in
whose name such certificate is to be registered shall be treated as a
stockholder of record of the Company, and all rights of the Holder of the
Security to be converted shall terminate, other than the right to receive the
shares of Common Stock and cash deliverable as provided in the preceding
sentence. A Holder of Securities is not entitled, as such, to any rights of a
holder of Common Stock until such Holder has converted its Securities into
shares of Common Stock, or is deemed to be a stockholder of record of the
Company, as provided in this Section 10.02(A), and then only to the extent such
Securities are deemed to have been so converted or such Holder is so deemed to
be a stockholder of record.

                  If a Security is duly surrendered for conversion in accordance
herewith, the Company shall have fully satisfied its obligations with respect to
such Security once the Company shall have duly delivered, in accordance
herewith, both (i) the shares of Common Stock, together with any cash payment
for fractional shares, due hereunder upon such conversion; and (ii) if such
Security shall have been surrendered for such conversion after the close of
business on the record date for the payment pursuant hereto of an installment of
interest but before the related interest payment date, such installment of
interest.

         (B) Except as provided in the Securities or in this Article X, no
payment or adjustment will be made for accrued interest on, or additional
interest with respect to, a

                                      -52-
<PAGE>
converted Security or for dividends on any Common Stock issued on or prior to
conversion. If any Holder surrenders a Security for conversion after the close
of business on the record date for the payment of an installment of interest and
prior to the related interest payment date, then, notwithstanding such
conversion, the interest payable with respect to such Security on such interest
payment date shall be paid on such interest payment date to the Holder of record
of such Security at the close of business on such record date; provided,
however, that such Security, when surrendered for conversion, must be
accompanied by payment in cash to the Conversion Agent on behalf of the Company
of an amount equal to the interest payable on such interest payment date on the
portion so converted; provided further, however, that such payment to the
Conversion Agent described in the immediately preceding proviso in respect of a
Security surrendered for conversion shall not be required if such Security is
called for Redemption pursuant to Section 3.04 and paragraphs 6 and 7 of the
Securities; provided further, that, if the Company shall have, prior to the
Conversion Date with respect to a Security, defaulted in a payment of interest
on such Security, then in no event shall the Holder of such Security who
surrenders such Security for conversion be required to pay such defaulted
interest or the interest that shall have accrued on such defaulted interest
pursuant to Section 2.12 or otherwise (it being understood that nothing in this
Section 10.02(B) shall affect the Company's obligations under Section 2.12).

         (C) If a Holder converts more than one Security at the same time, the
number of full shares of Common Stock issuable upon such conversion shall be
based on the total principal amount of all Securities converted.

         (D) Upon surrender of a Security that is converted in part, the Trustee
shall authenticate for the Holder a new Security equal in principal amount to
the unconverted portion of the Security surrendered.

         (E) If the last day on which a Security may be converted is a Legal
Holiday in a place where a Conversion Agent is located, the Security may be
surrendered to that Conversion Agent on the next succeeding day that is not a
Legal Holiday.

10.03 FRACTIONAL SHARES.

         The Company will not issue fractional shares of Common Stock upon
conversion of Securities and instead will deliver a check in an amount equal to
the value of such fraction computed on the basis of the Closing Sale Price on
the Trading Day immediately before the Conversion Date.

10.04 TAXES ON CONVERSION.

         If a Holder converts its Security, the Company shall pay any
documentary, stamp or similar issue or transfer tax or duty due on the issue, if
any, of shares of Common Stock upon the conversion. However, such Holder shall
pay any such tax or duty which is due because such shares are issued in a name
other than such Holder's name. The Conversion Agent may refuse to deliver a
certificate representing the shares of Common Stock to be issued in a name other
than such Holder's name until the Conversion Agent receives a sum sufficient to
pay any tax or duty

                                      -53-
<PAGE>
which will be due because such shares are to be issued in a name other than such
Holder's name. Nothing herein shall preclude any tax withholding required by law
or regulation.

10.05 COMPANY TO PROVIDE STOCK.

         The Company shall at all times reserve out of its authorized but
unissued Common Stock or Common Stock held in its treasury enough shares of
Common Stock to permit the conversion, in accordance herewith, of all of the
Securities into shares of Common Stock. The shares of Common Stock due upon
conversion of a Global Security shall be delivered by the Company in accordance
with the Depositary's customary practices.

         All shares of Common Stock which may be issued upon conversion of the
Securities shall be validly issued, fully paid and non-assessable and shall be
free of preemptive or similar rights and free of any lien or adverse claim.

         The Company shall comply with all securities laws regulating the offer
and delivery of shares of Common Stock upon conversion of Securities and shall
list such shares on each national securities exchange or automated quotation
system on which the Common Stock is listed.

10.06 ADJUSTMENT OF CONVERSION RATE.

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

                           (a) In case the Company shall (1) pay a dividend in
                  shares of Common Stock to all holders of Common Stock, (2)
                  make a distribution in shares of Common Stock to all holders
                  of Common Stock, (3) subdivide the outstanding shares of
                  Common Stock into a greater number of shares of Common Stock
                  or (4) combine the outstanding shares of Common Stock into a
                  smaller number of shares of Common Stock, the Conversion Rate
                  shall be adjusted by multiplying the Conversion Rate in effect
                  immediately prior to close of business on the record date or
                  effective date, as applicable, of such dividend, distribution,
                  subdivision or combination by the number of shares of Common
                  Stock which a person who owns only one share of Common Stock
                  immediately before the record date or effective date, as
                  applicable, of such dividend, distribution, subdivision or
                  combination and who is entitled to participate in such
                  dividend, distribution, subdivision or combination would own
                  immediately after giving effect to such dividend,
                  distribution, subdivision or combination (without giving
                  effect to any arrangement pursuant to such dividend,
                  distribution, subdivision or combination not to issue
                  fractional shares of Common Stock). Any adjustment made
                  pursuant to this Section 10.06(a) shall become effective
                  immediately after the record date in the case of a dividend or
                  distribution and shall become effective immediately after the
                  effective date in the case of a subdivision or combination.

                           (b) If the Company shall issue rights or warrants to
                  all or substantially all holders of Common Stock, entitling
                  them, for a period expiring not more than sixty (60) days
                  immediately following the record date for the determination of
                  holders of Common Stock entitled to receive such rights or
                  warrants, to subscribe

                                      -54-
<PAGE>
                  for or purchase shares of Common Stock (or securities
                  convertible into or exchangeable or exercisable for Common
                  Stock), at a price per share (or having a conversion, exchange
                  or exercise price per share) that is less than the current
                  market price (as determined pursuant to Section 10.06(g)) per
                  share of Common Stock on the record date for the determination
                  of holders of Common Stock entitled to receive such rights or
                  warrants, then the Conversion Rate shall be increased by
                  multiplying the Conversion Rate in effect immediately prior to
                  such record date by a fraction of which (A) the numerator
                  shall be the sum of (I) the number of shares of Common Stock
                  outstanding at the close of business on such record date and
                  (II) the aggregate number of shares (the "UNDERLYING SHARES")
                  of Common Stock underlying all such issued rights or warrants
                  (whether by exercise, conversion, exchange or otherwise), and
                  (B) the denominator shall be the sum of (I) number of shares
                  of Common Stock outstanding at the close of business on such
                  record date and (II) the number of shares of Common Stock
                  which the aggregate exercise, conversion, exchange or other
                  price at which the Underlying Shares may be subscribed for or
                  purchased pursuant to such rights or warrants would purchase
                  at such current market price. Such increase shall become
                  effective immediately prior to the opening of business on the
                  day following such record date. Notwithstanding the foregoing,
                  the Company shall not be required to make an adjustment to the
                  Conversion Rate pursuant to this Section 10.06(b) on account
                  of a distribution of rights (whether by distribution of
                  separate certificates representing such rights or otherwise),
                  provided that (i) such rights are distributed pursuant to a
                  stockholders' rights plan; and (ii) the Company makes adequate
                  provision, on the same basis set forth in the second sentence
                  of Section 10.06(c) with respect to Rights, and in accordance
                  with Section 10.14, for Holders, upon conversion of
                  Securities, to receive such rights in addition to any other
                  consideration payable hereunder with respect to such
                  conversion. In no event shall the Conversion Rate be decreased
                  pursuant to this Section 10.06(b).

                           (c) In case the Company shall dividend or distribute
                  to all or substantially all holders of Common Stock shares of
                  Capital Stock of the Company (other than Common Stock),
                  evidences of Indebtedness or other assets (other than
                  dividends or distributions requiring an adjustment to the
                  Conversion Rate in accordance with Sections 10.06(d) or
                  10.06(e)), or shall dividend or distribute to all or
                  substantially all holders of Common Stock rights or warrants
                  to subscribe for or purchase securities of the Company (other
                  than dividends or distributions of rights or warrants
                  requiring an adjustment to the Conversion Rate in accordance
                  with Section 10.06(b)), then in each such case the Conversion
                  Rate shall be increased by multiplying the Conversion Rate in
                  effect immediately prior to the close of business on the
                  record date for the determination of stockholders entitled to
                  such dividend or distribution by a fraction of which (A) the
                  numerator shall be the current market price of Common Stock
                  (as determined pursuant to Section 10.06(g)) on such record
                  date and (B) the denominator shall be an amount equal to (I)
                  such current market price less (II) the fair market value (as
                  determined in good faith by the Board of Directors, whose
                  determination shall be conclusive and described in a Board
                  Resolution), on such record date, of the portion of the shares
                  of Capital Stock, evidences of Indebtedness, assets, rights
                  and warrants to be

                                      -55-
<PAGE>
                  dividended or distributed applicable to one share of Common
                  Stock, such increase to become effective immediately prior to
                  the opening of business on the day following such record date;
                  provided, however, that if such denominator is equal to or
                  less than zero, then, in lieu of the foregoing adjustment to
                  the Conversion Rate, adequate provision shall be made so that
                  each Holder shall have the right to receive upon conversion of
                  its Securities, in addition to any consideration otherwise
                  payable as herein provided upon such conversion, an amount of
                  shares of Capital Stock, evidences of Indebtedness, assets,
                  rights and/or warrants that such Holder would have received
                  had such Holder converted all of its Securities on such record
                  date. Notwithstanding the foregoing, in the event that the
                  Company shall distribute rights or warrants (other than
                  distributions of rights or warrants requiring an adjustment to
                  the Conversion Rate in accordance with Section 10.06(b))
                  (collectively, "RIGHTS") to all or substantially all holders
                  of Common Stock, the Company may, in lieu of making any
                  adjustment pursuant to this Section 10.06(c), make proper
                  provision so that each Holder of a Security who converts such
                  Security (or any portion thereof) on or after the record date
                  for such distribution and prior to the expiration or
                  redemption of the Rights shall be entitled to receive upon
                  such conversion, in addition to the shares of Common Stock
                  issuable (and cash, if any, payable) upon such conversion (the
                  "CONVERSION SHARES"), a number of Rights to be determined as
                  follows: (i) if such conversion occurs on or prior to the date
                  for the distribution to the holders of Rights of separate
                  certificates evidencing such Rights (the "DISTRIBUTION DATE"),
                  the same number of Rights to which a holder of a number of
                  shares of Common Stock equal to the number of shares of
                  Conversion Shares would be entitled at the time of such
                  conversion in accordance with the terms and provisions of and
                  applicable to the Rights; and (ii) if such conversion occurs
                  after the Distribution Date, the same number of Rights to
                  which a holder of the number of shares of Common Stock into
                  which the principal amount of the Security so converted was
                  convertible immediately prior to the Distribution Date would
                  have been entitled on the Distribution Date in accordance with
                  the terms and provisions of and applicable to the Rights. Any
                  distribution of rights (whether by distribution of separate
                  certificates representing such rights or otherwise) or
                  warrants pursuant to a stockholders' rights plan complying
                  with the requirements set forth in the preceding sentence of
                  this paragraph and with Section 10.14 shall not constitute a
                  distribution of rights or warrants pursuant to this Section
                  10.06(c). In no event shall the Conversion Rate be decreased
                  pursuant to this Section 10.06(c).

                           (d) In case the Company shall, by dividend or
                  otherwise, at any time make a distribution of cash (excluding
                  any cash that is distributed as part of a distribution
                  requiring a Conversion Rate adjustment pursuant to Section
                  10.06(e)) to all or substantially all holders of Common Stock,
                  the Conversion Rate shall be increased by multiplying the
                  Conversion Rate in effect immediately prior to the close of
                  business on the record date for the determination of holders
                  of Common Stock entitled to such distribution by a fraction
                  (A) whose numerator shall be the current market price per
                  share of Common Stock (as determined pursuant to Section
                  10.06(g)) on such record date and (B) whose denominator shall
                  be an amount equal to (I) such current market price per share
                  of Common Stock less (II)

                                      -56-
<PAGE>
                  the amount of the distribution per share of Common Stock;
                  provided, however, that the Conversion Rate shall not be
                  adjusted pursuant to this Section 10.06(d) to the extent, and
                  only to the extent, such adjustment would cause the Conversion
                  Price to be less than one cent ($0.01); provided further that,
                  if the denominator of such fraction shall be equal to or less
                  than zero, the Conversion Rate shall be instead adjusted so
                  that the Conversion Price is equal to one cent ($0.01). An
                  adjustment to the Conversion Rate pursuant to this Section
                  10.06(d) shall become effective immediately prior to the
                  opening of business on the day immediately following such
                  record date. In no event shall the Conversion Rate be
                  decreased pursuant to this Section 10.06(d).

                           (e) In case the Company or any Subsidiary shall
                  distribute cash or other consideration in respect of a tender
                  offer or exchange offer made by the Company or any Subsidiary
                  for all or any portion of the Common Stock where the sum of
                  the aggregate amount of such cash distributed and the
                  aggregate fair market value (as determined in good faith by
                  the Board of Directors, whose determination shall be
                  conclusive and set forth in a Board Resolution), as of the
                  Expiration Date (as defined below), of such other
                  consideration distributed (such sum, the "AGGREGATE AMOUNT")
                  expressed as an amount per share of Common Stock validly
                  tendered or exchanged, and not withdrawn, pursuant to such
                  tender offer or exchange offer as of the Expiration Time (as
                  defined below) (such tendered or exchanged shares of Common
                  Stock, the "PURCHASED SHARES") exceeds the current market
                  price per share of Common Stock (as determined pursuant to
                  Section 10.06(g)) on the last date (such last date, the
                  "EXPIRATION DATE") on which tenders or exchanges could have
                  been made pursuant to such tender offer or exchange offer (as
                  the same may be amended through the Expiration Date), then the
                  Conversion Rate shall be increased by multiplying the
                  Conversion Rate in effect immediately prior to the close of
                  business on the Expiration Date by a fraction (A) whose
                  numerator is equal to the sum of (I) the Aggregate Amount and
                  (II) the product of (a) the current market price per share of
                  Common Stock (as determined pursuant to Section 10.06(g)) on
                  the Expiration Date and (b) an amount equal to (i) the number
                  of shares of Common Stock outstanding as of the last time (the
                  "EXPIRATION TIME") at which tenders or exchanges could have
                  been made pursuant to such tender offer or exchange offer
                  (including all Purchased Shares) less (ii) the Purchased
                  Shares and (B) whose denominator is equal to the product of
                  (I) the number of shares of Common Stock outstanding as of the
                  Expiration Time (including all Purchased Shares) and (II) the
                  current market price per share of Common Stock on the
                  Expiration Date.

                                    An increase, if any, to the Conversion Rate
                  pursuant to this Section 10.06(e) shall become effective
                  immediately prior to the opening of business on the Business
                  Day following the Expiration Date. In the event that the
                  Company or a Subsidiary is obligated to purchase shares of
                  Common Stock pursuant to any such tender offer or exchange
                  offer, but the Company or such Subsidiary is permanently
                  prevented by applicable law from effecting any such purchases,
                  or all such purchases are rescinded, then the Conversion Rate
                  shall again be adjusted to be the Conversion Rate which would
                  then be in effect if such

                                      -57-
<PAGE>
                  tender offer or exchange offer had not been made. If the
                  application of this Section 10.06(e) to any tender offer or
                  exchange offer would result in a decrease in the Conversion
                  Rate, no adjustment shall be made for such tender offer or
                  exchange offer under this Section 10.06(e).

                           (f) In addition to the foregoing adjustments in
                  Subsections (a), (b), (c), (d) and (e) above, the Company,
                  from time to time and to the extent permitted by law and by
                  the rules of the Nasdaq National Market, may increase the
                  Conversion Rate by any amount for a period of at least twenty
                  (20) days or such longer period as may be permitted by law, if
                  the Board of Directors has made a determination, which
                  determination shall be conclusive, that such increase would be
                  in the best interests of the Company. Such Conversion Rate
                  increase shall be irrevocable during such period. The Company
                  shall give written notice to the Trustee and cause notice of
                  such increase to be mailed, in accordance with Section 11.02,
                  to each Holder of Securities, at least fifteen (15) days prior
                  to the date on which such increase commences.

                           (g) For the purpose of any computation under
                  Subsections (a), (b), (c) or (d) above of this Section 10.06,
                  the current market price per share of Common Stock on the date
                  fixed for determination of the stockholders entitled to
                  receive the issuance or distribution requiring such
                  computation (the "DETERMINATION DATE") shall be deemed to be
                  the average of the Closing Sale Prices for the ten (10)
                  consecutive Trading Days immediately preceding the
                  Determination Date, and, for the purpose of any computation
                  under Section 10.06(e), the current market price per share of
                  Common Stock on the Expiration Date for the tender offer or
                  exchange offer requiring such computation shall be deemed to
                  be the average of the Closing Sale Price for the ten (10)
                  consecutive Trading Days immediately preceding the Expiration
                  Date; provided, however, that (i) if the Ex Date for any event
                  (other than the event requiring such computation) that
                  requires an adjustment to the Conversion Rate pursuant to
                  Subsection (a), (b), (c), (d) or (e) above occurs on or after
                  the tenth (10th) Trading Day prior to the Determination Date
                  or Expiration Date, whichever is applicable, and prior to the
                  Ex Date for the issuance or distribution requiring such
                  computation, the Closing Sale Price for each Trading Day prior
                  to the Ex Date for such other event shall be adjusted by
                  multiplying such Closing Sale Price by the reciprocal of the
                  fraction by which the Conversion Rate is so required to be
                  adjusted as a result of such other event, (ii) if the Ex Date
                  for any event (other than the event requiring such
                  computation) that requires an adjustment to the Conversion
                  Rate pursuant to Subsection (a), (b), (c), (d) or (e) above
                  occurs on or after the Ex Date for the issuance or
                  distribution requiring such computation and on or prior to the
                  Determination Date or the Expiration Date, whichever is
                  applicable, the Closing Sale Price for each Trading Day on and
                  after the Ex Date for such other event shall be adjusted by
                  multiplying such Closing Sale Price by the same fraction by
                  which the Conversion Rate is so required to be adjusted as a
                  result of such other event, and (iii) if the Ex Date for the
                  event requiring such computation is on or prior to the
                  Determination Date or Expiration Date, whichever is
                  applicable, after taking into account any adjustment required
                  pursuant to clause (i) or (ii) of this

                                      -58-
<PAGE>
                  proviso, the Closing Sale Price for each Trading Day on and
                  after such Ex Date shall be adjusted by adding thereto the
                  amount of any cash and the fair market value (as determined in
                  good faith by the Board of Directors in a manner consistent
                  with any determination of such value for the purposes of this
                  Section 10.06, whose determination shall be conclusive and
                  described in a Resolution of the Board of Directors) of the
                  evidences of Indebtedness, shares of Capital Stock or other
                  securities or assets or cash being distributed (in the event
                  requiring such computation) applicable to one share of Common
                  Stock as of the close of business on the day before such Ex
                  Date.

                                    The term "EX DATE," (i) when used with
                  respect to any issuance or distribution, means the first date
                  on which the Common Stock trades the regular way on the
                  relevant exchange or in the relevant market from which the
                  Closing Sale Price was obtained without the right to receive
                  such issuance or distribution, (ii) when used with respect to
                  any subdivision or combination of shares of Common Stock,
                  means the first date on which the Common Stock trades the
                  regular way on such exchange or in such market after the time
                  at which such subdivision or combination becomes effective,
                  and (iii) when used with respect to any tender offer or
                  exchange offer means the first date on which the Common Stock
                  trades the regular way on such exchange or in such market
                  after the expiration time of such tender offer or exchange
                  offer (as it may be amended or extended).

10.07 NO ADJUSTMENT.

         Notwithstanding anything to the contrary in Section 10.06, no
adjustment in the Conversion Rate pursuant to Section 10.06 shall be required
until cumulative adjustments amount to one percent (1%) or more of the
Conversion Rate as last adjusted (or, if never adjusted, the initial Conversion
Rate); provided, however, that any adjustments to the Conversion Rate which by
reason of this Section 10.07 are not required to be made shall be carried
forward and taken into account in any subsequent adjustment to the Conversion
Rate. All calculations under this Article X shall be made to the nearest cent or
to the nearest one-millionth of a share, as the case may be.

         Notwithstanding anything to the contrary in Section 10.06, if any
rights, options or warrants issued by the Company and requiring an adjustment to
the Conversion Rate in accordance with Section 10.06 are only exercisable upon
the occurrence of certain triggering events, then the Conversion Rate will not
be adjusted as provided in Section 10.06 until the earliest of such triggering
event occurs. Upon the expiration or termination of any such rights, options or
warrants without the exercise of such rights, options or warrants, the
Conversion Rate then in effect shall be adjusted immediately to the Conversion
Rate which would have been in effect at the time of such expiration or
termination had such rights, options or warrants, to the extent outstanding
immediately prior to such expiration or termination, never been issued.

         Notwithstanding anything to the contrary in Section 10.06, if any
dividend or distribution is declared and the Conversion Rate is adjusted
pursuant to Section 10.06 on account of such dividend or distribution, but such
dividend or distribution is thereafter not paid or made, the

                                      -59-
<PAGE>
Conversion Rate shall again be adjusted to the Conversion Rate which would then
be in effect had such dividend or distribution not been declared.

         Notwithstanding anything to the contrary in Section 10.06, no
adjustment to the Conversion Rate need be made pursuant to Section 10.06 for a
transaction if Holders are to participate in the transaction without conversion
on a basis and with notice that the Board of Directors determines in good faith
to be fair and appropriate in light of the basis and notice on which holders of
Common Stock participate in the transaction (which determination shall be
described in a Board Resolution).

         No adjustment to the Conversion Rate need be made pursuant to Section
10.06 solely as a result of distributions or dividends solely on any preferred
stock of the Company.

         Except as otherwise provided in this Indenture, no adjustment to the
Conversion Rate shall be required pursuant to Section 10.06 for the issuance of
Common Stock or the right to purchase Common Stock or any security that is
convertible or exchangeable for Common Stock.

10.08 OTHER ADJUSTMENTS.

         In the event that, as a result of an adjustment made pursuant to
Section 10.06 hereof, the Holder of any Security thereafter surrendered for
conversion shall become entitled to receive any shares of Capital Stock other
than shares of Common Stock, thereafter the Conversion Rate of such other shares
so receivable upon conversion of any Security shall be subject to adjustment
from time to time in a manner and on terms as nearly equivalent as practicable
to the provisions with respect to Common Stock contained in this Article X.

10.09 ADJUSTMENTS FOR TAX PURPOSES.

         Except as prohibited by law or by the rules of the Nasdaq National
Market, the Company may make such increases in the Conversion Rate, in addition
to those required by Section 10.06 hereof, as it determines to be advisable in
order to eliminate or diminish any income taxes to holders of Common Stock
resulting from any stock dividend, subdivision of shares, distribution of rights
to purchase stock or securities or distribution of securities convertible into
or exchangeable for stock made by the Company or to its stockholders.

10.10 NOTICE OF ADJUSTMENT.

         Whenever the Conversion Rate is adjusted, the Company shall promptly
mail, or cause there to be mailed, to Holders at the addresses appearing on the
Registrar's books a notice of the adjustment and file with the Trustee an
Officer's Certificate briefly stating the facts requiring the adjustment and the
manner of computing it. The certificate shall be conclusive evidence of the
correctness of such adjustment.

                                      -60-
<PAGE>
10.11 NOTICE OF CERTAIN TRANSACTIONS.

         In the event that:

                           (1) the Company takes any action, or becomes aware of
                  any event, which would require an adjustment in the Conversion
                  Rate,

                           (2) the Company takes any action that would require a
                  supplemental indenture pursuant to Section 10.12, or

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

the Company shall mail to Holders at the addresses appearing on the Registrar's
books and the Trustee a written notice stating the proposed record, effective or
expiration date, as the case may be, of any transaction referred to in clause
(1), (2) or (3) of this Section 10.11. The Company shall mail such notice at
least twenty (20) days before such date; however, failure to mail such notice or
any defect therein shall not affect the validity of any transaction referred to
in clause (1), (2) or (3) of this Section 10.11.

10.12 EFFECT OF RECLASSIFICATIONS, CONSOLIDATIONS, MERGERS, BINDING SHARE
EXCHANGES OR SALES ON CONVERSION PRIVILEGE.

         Except as provided in Section 10.15(F), if any of the following shall
occur, namely: (i) any reclassification or change in the Common Stock issuable
upon conversion of Securities (other than a change in par value, or from par
value to no par value, or from no par value to par value, or as a result of a
subdivision or combination of the Common Stock), (ii) any consolidation, merger
or binding share exchange to which the Company is a party other than a merger in
which the Company is the continuing Person and which does not result in any
reclassification of, or change (other than a change in name, or par value, or
from par value to no par value, or from no par value to par value or as a result
of a subdivision or combination) in, the Common Stock or (iii) any sale,
transfer, lease, conveyance or other disposition of all or substantially all of
the property or assets of the Company, in each case pursuant to which the Common
Stock would be converted into, or exchanged for, cash, securities or other
property, then the Company or such successor or purchasing Person, as the case
may be, shall, as a condition precedent to such reclassification, change,
consolidation, merger, binding share exchange, sale, transfer, lease, conveyance
or disposition, execute and deliver to the Trustee a supplemental indenture in
form reasonably satisfactory to the Trustee providing that, at and after the
effective time of such reclassification, change, consolidation, merger, binding
share exchange, sale, transfer, lease, conveyance or disposition, the Holder of
each Security then outstanding shall have the right to convert such Security
into the kind and amount of shares of stock and other securities and property
(including cash), if any, receivable upon such reclassification, change,
consolidation, merger, binding share exchange, sale, transfer, lease, conveyance
or disposition by a holder of the number of shares of Common Stock deliverable
upon conversion of such Security immediately prior to such reclassification,
change, consolidation, merger, binding share exchange, sale, transfer, lease,
conveyance or disposition, assuming that such Holder would not have exercised
any rights of election that such Holder would have had as a holder of Common
Stock to select a particular type of consideration. Such

                                      -61-
<PAGE>
supplemental indenture shall provide for adjustments of the Conversion Rate
which shall be as nearly equivalent as may be practicable to the adjustments of
the Conversion Rate provided for in this Article X. The foregoing, however,
shall not in any way affect the right a Holder of a Security may otherwise have,
pursuant to Section 10.06(c), Section 10.06(b) or Section 10.14, to receive
rights or warrants upon conversion of a Security. If, in the case of any such
consolidation, merger, binding share exchange, sale, transfer, lease, conveyance
or disposition, the stock or other securities and property (including cash)
receivable thereupon by a holder of Common Stock includes shares of stock or
other securities and property of a Person other than the successor or purchasing
Person, as the case may be, in such consolidation, merger, binding share
exchange, sale, transfer, lease, conveyance or disposition, then such
supplemental indenture shall also be executed by such other Person and shall
contain such additional provisions to protect the interests of the Holders of
the Securities as the Board of Directors in good faith shall reasonably
determine necessary by reason of the foregoing (which determination shall be
described in a Board Resolution). The provisions of this Section 10.12 shall
similarly apply to successive consolidations, mergers, binding share exchanges,
sales, transfers, leases, conveyances or dispositions.

         In the event the Company shall execute a supplemental indenture
pursuant to this Section 10.12, the Company shall promptly file with the Trustee
an Officer's Certificate briefly stating the reasons therefor, the kind or
amount of shares of stock or securities or property (including cash) receivable
by Holders of the Securities upon the conversion of their Securities after any
such reclassification, change, consolidation, merger, binding share exchange,
sale, transfer, lease, conveyance or disposition and any adjustment to be made
with respect thereto.

10.13 TRUSTEE'S DISCLAIMER.

         The Trustee has no duty to determine when an adjustment under this
Article X should be made, how it should be made or what such adjustment should
be, but may accept as conclusive evidence of the correctness of any such
adjustment, and shall be protected in relying upon, the Officer's Certificate
with respect thereto which the Company is obligated to file with the Trustee
pursuant to Section 10.10 hereof. The Trustee makes no representation as to the
validity or value of any securities or assets issued upon conversion of
Securities, and the Trustee shall not be responsible for the failure by the
Company to comply with any provisions of this Article X.

         The Trustee shall not be under any responsibility to determine the
correctness of any provisions contained in any supplemental indenture executed
pursuant to Section 10.12, but may accept as conclusive evidence of the
correctness thereof, and shall be protected in relying upon, the Officer's
Certificate with respect thereto which the Company is obligated to file with the
Trustee pursuant to Section 10.12 hereof. Neither the Trustee nor any Conversion
Agent shall be responsible for any failure of the Company to (A) make any cash
payment or issue, transfer or deliver any shares of Common Stock or stock
certificates or other securities or property upon the surrender of any Security
for conversion hereunder, or (B) subject to Article VII, comply with any of the
covenants of the Company hereunder.

                                      -62-
<PAGE>
10.14 RIGHTS DISTRIBUTIONS PURSUANT TO STOCKHOLDERS' RIGHTS PLANS.

         Upon conversion of any Security or a portion thereof, the Company shall
make provision for the Holder thereof to receive, in addition to, and
concurrently with the delivery of, the consideration otherwise payable hereunder
upon such conversion, the rights described in each and any stockholders' rights
plan the Company may have in effect at such time (whether or not the rights have
been separated from the Common Stock prior to the time of conversion). In the
event that the Company implements a stockholders' rights plan after the date
hereof, the Company shall provide that the Holders will receive upon conversion
of their Securities, in addition to the consideration otherwise payable
hereunder upon such conversion, the rights described therein (whether or not the
rights have been separated from the Common Stock prior to the time of
conversion).

10.15 INCREASED CONVERSION RATE APPLICABLE TO CERTAIN NOTES SURRENDERED IN
CONNECTION WITH MAKE-WHOLE FUNDAMENTAL CHANGES.

         (A) Notwithstanding anything herein to the contrary, the Conversion
Rate applicable to each Security that is surrendered for conversion, in
accordance with this Article X, at any time from, and including, the date that
is fifteen (15) Business Days prior to the date originally announced by the
Company as the anticipated effective date of a Make-Whole Fundamental Change
(which anticipated effective date the Company shall disclose, in good faith, in
the written notice, public announcement and publication referred to in Section
10.15(E)) until, and including, the date that is fifteen (15) Business Days
after the actual effective date of such Make-Whole Fundamental Change shall be
increased to an amount equal to the Conversion Rate that would, but for this
Section 10.15, otherwise apply to such Security pursuant to this Article X, plus
an amount equal to the Make-Whole Conversion Rate Adjustment; provided, however,
that such increase to the Conversion Rate shall not apply if either:

                  (i) such Make-Whole Fundamental Change constitutes a Public
         Acquirer Fundamental with respect to which the Company shall have duly
         made, and given full effect to, an election, pursuant to and in
         accordance with Section 10.15(F), to make an Acquirer Stock Conversion
         Right Adjustment; or

                  (ii) such Make-Whole Fundamental Change is announced by the
         Company but shall not be consummated.

                  The additional consideration payable hereunder on account of
any Make-Whole Conversion Rate Adjustment with respect to a Security surrendered
for conversion is herein referred to as the "MAKE-WHOLE CONSIDERATION."

         (B) As used herein, "MAKE-WHOLE CONVERSION RATE ADJUSTMENT" shall mean,
with respect to each Make-Whole Fundamental Change and each applicable Security,
an amount equal to a fraction whose numerator is the product of the Applicable
Increase and the principal amount of such Security to be converted and whose
denominator is one thousand dollars ($1,000). As used herein, "APPLICABLE
INCREASE" shall mean, with respect to a Make-Whole Fundamental Change, the
amount, set forth in the following table, which corresponds to the

                                      -63-
<PAGE>
effective date of such Make-Whole Fundamental Change (the "EFFECTIVE DATE") and
the Applicable Price of such Make-Whole Fundamental Change:

                               APPLICABLE INCREASE
                   (per $1,000 principal amount of Securities)

<TABLE>
<CAPTION>
                                                                 EFFECTIVE DATE
                                                                 --------------
                       JANUARY     FEBRUARY    FEBRUARY     FEBRUARY    FEBRUARY    FEBRUARY     FEBRUARY    FEBRUARY
APPLICABLE PRICE      25, 2005     1, 2006     1, 2007      1, 2008     1, 2009      1, 2010      1, 2011     1, 2012
----------------      --------     -------     -------      -------     -------      -------      -------     -------
<S>                   <C>          <C>         <C>          <C>         <C>         <C>          <C>          <C>
$  8.97.......           37.76       39.53       38.38        36.95       35.06        32.34        28.07        0.00
$ 12.50.......           22.80       23.77       22.55        20.99       18.89        15.86        10.98        0.00
$ 15.00.......           17.01       17.74       16.61        15.17       13.26        10.54         6.36        0.00
$ 17.50.......           13.14       13.73       12.72        11.44        9.76         7.44         4.09        0.00
$ 20.00.......           10.41       10.91       10.02         8.90        7.45         5.51         2.89        0.00
$ 22.50.......            8.39        8.85        8.06         7.09        5.85         4.24         2.20        0.00
$ 25.00.......            6.87        7.29        6.60         5.75        4.70         3.37         1.78        0.00
$ 27.50.......            5.68        6.08        5.47         4.74        3.84         2.74         1.50        0.00
$ 30.00.......            4.73        5.12        4.59         3.95        3.18         2.27         1.29        0.00
$ 32.50.......            3.97        4.35        3.88         3.32        2.67         1.91         1.14        0.00
$ 35.00.......            3.35        3.72        3.31         2.82        2.26         1.62         1.01        0.00
$ 37.50.......            2.84        3.20        2.83         2.41        1.93         1.40         0.91        0.00
$ 40.00.......            2.41        2.76        2.44         2.07        1.65         1.21         0.82        0.00
$ 42.50.......            2.05        2.40        2.11         1.79        1.43         1.06         0.74        0.00
$ 45.00.......            1.74        2.08        1.83         1.55        1.24         0.93         0.68        0.00
$ 47.50.......            1.48        1.82        1.60         1.35        1.08         0.82         0.62        0.00
$ 50.00.......            1.26        1.59        1.39         1.17        0.95         0.73         0.56        0.00
$ 52.50.......            1.07        1.39        1.22         1.03        0.83         0.65         0.52        0.00
</TABLE>

            provided, however, that:

                  (i) if the actual Applicable Price of such Make-Whole
         Fundamental Change is between two (2) prices listed in the table above
         under the column titled "Applicable Price," or if the actual Effective
         Date of such Make-Whole Fundamental Change is between two dates listed
         in the table above in the row immediately below the title "Effective
         Date," then the Applicable Increase for such Make-Whole Fundamental
         Change shall be determined by linear interpolation between the
         Applicable Increases set forth for such two prices, or for such two
         dates based on a three hundred and sixty five (365) day year, as
         applicable;

                  (ii) if the actual Applicable Price of such Make-Whole
         Fundamental Change is greater than $52.50 per share (subject to
         adjustment as provided in Section 10.15(B)(iii)), or if the actual
         Applicable Price of such Make-Whole Fundamental Change is less than
         $8.97 per share (subject to adjustment as provided in Section
         10.15(B)(iii)), then the Applicable Increase shall be equal to zero (0)
         and this Section 10.15 shall not require the Company to increase the
         Conversion Rate with respect to such Make-Whole Fundamental Change;

                  (iii) if an event occurs that requires, pursuant to this
         Article X (other than solely pursuant to this Section 10.15), an
         adjustment to the Conversion Rate, then, on the date and at the time
         such adjustment is so required to be made, each price set forth in the
         table above under the column titled "Applicable Price" shall be deemed
         to be adjusted so that such price, at and after such time, shall be
         equal to the product of (1) such price as in effect immediately before
         such adjustment to such price and (2) a fraction whose numerator is the
         Conversion Rate in effect immediately before such

                                      -64-
<PAGE>
         adjustment to the Conversion Rate and whose denominator is the
         Conversion Rate to be in effect, in accordance with this Article X,
         immediately after such adjustment to the Conversion Rate;

                  (iv) each Applicable Increase amount set forth in the table
         above shall be adjusted in the same manner in which, and for the same
         events for which, the Conversion Rate is to be adjusted pursuant to
         Section 10.01 through Section 10.14; and

                  (v) in no event shall the Conversion Rate applicable to any
         Security be increased pursuant to this Section 10.15 to the extent, but
         only to the extent, such increase shall not be permitted by the
         continued listing standards of the Nasdaq National Market; provided,
         however, that any reduction, pursuant to this Section 10.15(B)(v), in
         such increase to the Conversion Rate shall be made by the Company in
         good faith and, to the extent practical, pro rata in accordance with
         the principal amount of Securities surrendered for conversion in
         connection with the applicable Make-Whole Fundamental Change.

         (C) As used herein, "APPLICABLE PRICE" shall have the following meaning
with respect to a Make-Whole Fundamental Change: (a) if the consideration
(excluding cash payments for fractional shares or pursuant to statutory
appraisal rights) for the Common Stock in such Make-Whole Fundamental Change
consists solely of cash, then the "Applicable Price" with respect to such
Make-Whole Fundamental Change shall be equal to the cash amount paid per share
of Common Stock in such Make-Whole Fundamental Change; and (b) in all other
circumstances, the "Applicable Price" with respect to such Make-Whole
Fundamental Change shall be equal to the average of the Closing Sale Prices per
share of Common Stock for the five (5) consecutive Trading Days immediately
preceding the Effective Date of such Make-Whole Fundamental Change, which
average shall be appropriately adjusted by the Board of Directors, in its good
faith determination (which determination shall be described in a Board
Resolution), to account for any adjustment, pursuant hereto, to the Conversion
Rate that shall become effective, or any event requiring, pursuant hereto, an
adjustment to the Conversion Rate where the Ex Date of such event occurs, at any
time during such five (5) consecutive Trading Days.

         (D) The Company shall cause any Make-Whole Consideration payable,
pursuant to this Section 10.15, with respect to a Security, in connection with
the conversion of such Security pursuant to Article X, to be paid, through the
Conversion Agent, as soon as practicable, but in no event after the later of (a)
the date such Security is surrendered for such conversion and (b) the fifth
(5th) Business Day immediately following the Effective Date of the applicable
Make-Whole Fundamental Change. The consideration in which the Make-Whole
Consideration is payable shall be determined in accordance herewith, including,
without limitation, in accordance, to the extent applicable, with Section 10.12.

         (E) At least fifteen (15) Business Days before the anticipated
effective date of each proposed Make-Whole Fundamental Change, the Company shall
mail to each Holder, in accordance with Section 11.02, written notice of, and
shall publicly announce, through a reputable national newswire service, and
publish on the Company's website, the anticipated effective date of such
proposed Make-Whole Fundamental Change. Each such notice,

                                      -65-
<PAGE>
announcement and publication shall also state (i) that the Company either (a)
has elected, in accordance with Section 10.15(F), to make an Acquirer Stock
Conversion Right Adjustment with respect to such Make-Whole Fundamental Change
in lieu of increasing the Conversion Rate pursuant to Section 10.15(A) or (b)
has elected not to make an Acquirer Stock Conversion Right Adjustment with
respect to such Make-Whole Fundamental Change; and (ii) if the Company has
elected not to make such Acquirer Stock Conversion Right Adjustment with respect
to such Make-Whole Fundamental Change, that, in connection with such Make-Whole
Fundamental Change, the Company shall increase, in accordance herewith, the
Conversion Rate applicable to Securities entitled as provided herein to such
increase (along with a description of how such increase shall be calculated and
the time periods during which Securities must be surrendered in order to be
entitled to such increase). No later than the actual Effective Date of each
Make-Whole Fundamental Change, the Company shall mail, in accordance with
Section 11.02, written notice of, and shall publicly announce, through a
reputable national newswire service, and publish on the Company's website, such
Effective Date.

         (F) Notwithstanding anything to the contrary in this Section 10.15, if
the Company shall make any mailing, announcement or publication referred to in
Section 10.15(E) in respect of a Make-Whole Fundamental Change that shall also
constitute a Public Acquirer Fundamental Change, then the Company shall have the
right to, in lieu of increasing the Conversion Rate pursuant to Section 10.15(A)
in connection with such Make-Whole Fundamental Change, cause the right to
convert the Securities in accordance with this Article X to change such that,
from and after the effective time of such Public Acquirer Fundamental Change,
the right of each Holder of any Security to convert such Security into shares of
Common Stock and cash for fractional shares shall be changed into the right to
convert such Security solely into shares of Public Acquirer Common Stock
applicable to such Public Acquirer Fundamental Change and cash for fractional
shares thereof, at an initial Conversion Rate (which shall take effect at such
effective time, but which shall thereafter be subject to adjustment in the same
manner in which, and for the same events for which, the Conversion Rate is to be
adjusted pursuant to this Article X) equal to the Conversion Rate in effect
immediately before such effective time multiplied by a fraction whose numerator
is the Reference Price and whose denominator is the average of the last reported
sale prices per share of such Public Acquirer Common Stock for the five (5)
consecutive Trading Days commencing on, and including, the Trading Day
immediately after the effective date of such Public Acquirer Fundamental Change,
which average shall be appropriately adjusted by the Board of Directors, in its
good faith determination (which determination shall be described in a Board
Resolution), to account for any event that, assuming such Public Acquirer Common
Stock were Common Stock, would require, pursuant hereto, an adjustment to the
Conversion Rate to become effective, or any such event whose Ex Date occurs, at
any time during such five (5) consecutive Trading Days. Any such change in the
right to convert the Securities in accordance with this Section 10.15(F) is
herein referred to as an "ACQUIRER STOCK CONVERSION RIGHT ADJUSTMENT."

                  If the Company shall have elected, in accordance with this
Section 10.15(F), to make an Acquirer Stock Conversion Right Adjustment with
respect to a Public Acquirer Fundamental Change, then:

                  (i) the Company shall cause there to be executed and delivered
         to the Trustee a supplemental indenture in form reasonably satisfactory
         to the Trustee, which

                                      -66-
<PAGE>
         supplemental indenture shall (a) give due effect to such election in
         accordance with this Section 10.15(F), including, without limitation,
         evidencing a binding and enforceable obligation of the issuer of the
         applicable Public Acquirer Common Stock to satisfy the right of Holders
         to convert Securities in accordance with this Article X and this
         Section 10.15(F); (b) be executed by, without limitation, such issuer;
         (c) contain such additional provisions to protect the interests of the
         Holders of the Securities as the Board of Directors in good faith shall
         reasonably determine (which determination shall be described in a Board
         Resolution); and (d) be in full force and effect no later than the
         effective time of such Public Acquirer Fundamental Change;

                  (ii) the Company shall promptly file with the Trustee an
         Officer's Certificate briefly stating the reasons for such supplemental
         indenture, the nature of the change in the conversion right pursuant to
         such Acquirer Stock Conversion Right Adjustment and the Conversion Rate
         as adjusted therefor;

                  (iii) the provisions of Section 10.12 shall not apply to such
         Public Acquirer Fundamental Change, provided such Public Acquirer
         Fundamental Change shall have been duly given effect in accordance with
         this Section 10.15(F); and

                  (iv) such election shall be irrevocable with respect to such
         Public Acquirer Fundamental Change and shall be deemed to have been
         made at the time the Company shall, with respect to such Public
         Acquirer Fundamental Change, mail the first notice, or make the first
         public announcement or publication, whichever shall occur earlier,
         referred to in Section 10.15(E) (it being understood that the Company
         shall discharge its obligations hereunder in good faith in determining
         whether an announced transaction and a completed transaction are
         deemed, for purposes of this clause (iv), to be the same Public
         Acquirer Fundamental Change despite differences in the announced terms
         and the terms as such transaction was consummated);

provided, however, that the Company shall not be required to give effect to such
election to make an Acquirer Stock Conversion Right Adjustment with respect to
such Public Acquirer Fundamental Change if such Public Acquirer Fundamental
Change is not consummated.

                  For avoidance of doubt, any change, pursuant to this Section
10.15(F), in the right of Holders to convert Securities shall apply to all
Holders.

                  As used herein, "REFERENCE PRICE" shall have the following
meaning with respect to a Public Acquirer Fundamental Change: (a) if such Public
Acquirer Fundamental Change shall be a share exchange, consolidation, merger or
binding share exchange pursuant to which the Common Stock is converted into
cash, securities or other property, then the "Reference Price" with respect to
such Public Acquirer Fundamental Change shall mean the fair market value (as
determined in good faith by the Board of Directors, which determination shall be
described in a Board Resolution), as of the effective time of such Public
Acquirer Fundamental Change, of such cash, securities and other property paid or
payable pursuant to such Public Acquirer Fundamental Change per share of Common
Stock; and (b) in all other circumstances, the "Reference Price" with respect to
such Public Acquirer Fundamental Change shall mean the average of the Closing
Sale Prices per share of Common Stock for the five (5) consecutive Trading Days
immediately

                                      -67-
<PAGE>
preceding, and excluding, the effective date of such Public Acquirer Fundamental
Change, which average shall be appropriately adjusted by the Board of Directors,
in its good faith determination (which determination shall be described in a
Board Resolution), to account for any adjustment, pursuant hereto, to the
Conversion Rate that shall become effective, or any event requiring, pursuant
hereto, an adjustment to the Conversion Rate where the Ex Date of such event
occurs, at any time during such five (5) consecutive Trading Days.

         (G) For avoidance of doubt, the provisions of this Section 10.15 shall
not affect or diminish the Company's obligations, if any, pursuant to Article V
with respect to a Public Acquirer Fundamental Change or Make-Whole Fundamental
Change.

         (H) Nothing in this Section 10.15 shall prevent an adjustment to the
Conversion Rate pursuant to Section 10.06 in respect of a Make-Whole Fundamental
Change or a Public Acquirer Fundamental Change.

                               XI. MISCELLANEOUS

11.01 TRUST INDENTURE ACT CONTROLS.

         If any provision of this Indenture limits, qualifies or conflicts with
another provision which is required or deemed to be included in this Indenture
by the TIA, then such provision of the TIA shall control.

11.02 NOTICES.

         Any notice or communication by the Company or the Trustee to the other
shall be deemed to be duly given if made in writing and delivered:

         (A) by hand (in which case such notice shall be effective upon
delivery);

         (B) by facsimile (in which case such notice shall be effective upon
receipt of confirmation of good transmission thereof); or

         (C) by overnight delivery by a nationally recognized courier service
(in which case such notice shall be effective on the Business Day immediately
after being deposited with such courier service),

in each case to the other party's address or facsimile number, as applicable,
stated in this Section 11.02. The Company or the Trustee by notice to the other
may designate additional or different addresses for subsequent notices or
communications.

         Any notice or communication to a Holder shall be mailed to its address
shown on the register kept by the Registrar. Failure to mail a notice or
communication to a Holder or any defect in it shall not affect its sufficiency
with respect to other Holders.

         If a notice or communication is mailed in the manner provided above, it
is duly given, whether or not the addressee receives it.

                                      -68-
<PAGE>

      If the Company mails a notice or communication to Holders, it shall mail a
copy to the Trustee and each Security Agent at the same time.

      All notices or communications shall be in writing.

      The Company's address is:

      Antigenics Inc.
      630 Fifth Avenue
      Suite 2100
      New York, NY 10111
      Fax: (212) 994-8299
      Attn: Chief Financial Officer

      The Trustee's address is:

      HSBC Bank USA, National Association
      Issuer Services
      452 Fifth Avenue
      New York, NY 10018
      Fax: (212) 525-1300
      Attn: Mr. Frank J. Godino
      Hand Delivery address:
      10 East 40th Street, 14th Floor
      New York, NY 10016

      If the Trustee is required, pursuant to the express terms of this
Indenture, to mail a notice or communication to Holders, the Trustee shall also
mail a copy of such notice or communication to the Company.

11.03 COMMUNICATION BY HOLDERS WITH OTHER HOLDERS.

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

11.04 CERTIFICATE AND OPINION AS TO CONDITIONS PRECEDENT.

      Upon any request or application by the Company to the Trustee to take any
action under this Indenture, the Company shall furnish to the Trustee:

            (i) an Officer's Certificate stating that, in the opinion of the
      signatory to such Officer's Certificate, all conditions precedent, if any,
      provided for in this Indenture relating to the proposed action have been
      complied with; and

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


                                      -69-
<PAGE>
      Each signatory to an Officer's Certificate or an Opinion of Counsel may
(if so stated) rely, effectively, upon an Opinion of Counsel as to legal matters
and an Officer's Certificate or certificates of public officials as to factual
matters if such signatory reasonably and in good faith believes in the accuracy
of the document relied upon.

11.05 STATEMENTS REQUIRED IN CERTIFICATE OR OPINION.

      Each Officer's Certificate or Opinion of Counsel with respect to
compliance with a condition or covenant provided for in this Indenture shall
include:

            (i) a statement that the person making such certificate or opinion
      has read such covenant or condition;

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

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

            (iv) a statement as to whether or not, in the opinion of such
      person, such condition or covenant has been complied with.

11.06 RULES BY TRUSTEE AND AGENTS.

      The Trustee may make reasonable rules for action by or at a meeting of
Holders. The Registrar, Paying Agent or Conversion Agent may make reasonable
rules and set reasonable requirements for their respective functions.

11.07 LEGAL HOLIDAYS.

      A "LEGAL HOLIDAY" is a Saturday, a Sunday or a day on which banking
institutions are not required to be open in the City of New York, in the State
of New York or in the city in which the Trustee administers its corporate trust
business. If a payment date is a Legal Holiday at a place of payment, payment
may be made at that place on the next succeeding day that is not a Legal
Holiday, and no interest shall accrue on that payment for the intervening
period.

      A "BUSINESS DAY" is a day other than a Legal Holiday.

11.08 DUPLICATE ORIGINALS.

      The parties may sign any number of copies of this Indenture. Each signed
copy shall be an original, but all of them together represent the same
agreement. Delivery of an executed counterpart by facsimile shall be effective
as delivery of a manually executed counterpart thereof.


                                      -70-
<PAGE>
11.09 GOVERNING LAW.

      The laws of the State of New York shall govern this Indenture and the
Securities.

11.10 NO ADVERSE INTERPRETATION OF OTHER AGREEMENTS.

      This Indenture may not be used to interpret another indenture, loan or
debt agreement of the Company or any of its Subsidiaries. Any such indenture,
loan or debt agreement may not be used to interpret this Indenture.

11.11 SUCCESSORS.

      All agreements and covenants of the Company in this Indenture and the
Securities shall bind its successors. All agreements and covenants of the
Trustee in this Indenture shall bind its successors.

11.12 SEPARABILITY.

      In case any provision in this Indenture or in the Securities shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions shall not in any way be affected or impaired thereby
and a Holder shall have no claim therefor against any party hereto.

11.13 TABLE OF CONTENTS, HEADINGS, ETC.

      The Table of Contents, Cross-Reference Table and headings of the Articles
and Sections of this Indenture have been inserted for convenience of reference
only, are not to be considered a part hereof and shall in no way modify or
restrict any of the terms or provisions hereof.

11.14 CALCULATIONS IN RESPECT OF THE SECURITIES.

      The Company or its agents shall make all calculations under this Indenture
and the Securities in good faith. In the absence of manifest error, such
calculations shall be final and binding on all Holders. The Company shall
provide a copy of such calculations to the Trustee as required hereunder, and,
absent contrary written notice by the Company to the Trustee, the Trustee shall
be entitled to rely on the accuracy of any such calculation without independent
verification.

11.15 NO PERSONAL LIABILITY OF DIRECTORS, EMPLOYEES OR STOCKHOLDERS

      None of the Company's past, present or future directors, officers,
employees or stockholders, as such, shall have any liability for any of the
Company's obligations under this Indenture or the Securities or for any claim
based on, or in respect or by reason of, such obligations or their creation.
Except as otherwise provided by applicable law, by accepting a Security, each
Holder waives and releases all such liability and such waiver and release is
part of the consideration for the issue of the Securities.

  [THE REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK; SIGNATURE PAGE FOLLOWS]


                                      -71-
<PAGE>
      IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed as of the date first above written.

                                        ANTIGENICS INC.


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



                                        HSBC BANK USA, NATIONAL ASSOCIATION,
                                           as Trustee



                                        By:
                                           -------------------------------------
                                           Name:
                                           Title:
<PAGE>
                                                                       EXHIBIT A

                               [Face of Security]

                                 ANTIGENICS INC.

Certificate No. _______

    [INSERT PRIVATE PLACEMENT LEGEND AND GLOBAL SECURITY LEGEND AS REQUIRED]


                     5.25% Convertible Senior Note due 2025

                             CUSIP No. ____________

      Antigenics Inc., a Delaware corporation (the "COMPANY"), for value
received, hereby promises to pay to Cede & Co., or its registered assigns, the
principal sum of _____________________ dollars ($__________) on February 1, 2025
and to pay interest thereon, as provided on the reverse hereof, until the
principal and any unpaid and accrued interest are paid or duly provided for.

      Interest Payment Dates: February 1 and August 1, with the first payment to
be made on August 1, 2005.

      Record Dates: January 15 and July 15.

      The provisions on the back of this certificate are incorporated as if set
forth on the face hereof.

      IN WITNESS WHEREOF, Antigenics Inc. has caused this instrument to be duly
signed.

                                        ANTIGENICS INC.



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


Dated: ________________


                                      A-1
<PAGE>
TRUSTEE'S CERTIFICATE OF AUTHENTICATION

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

HSBC BANK USA, NATIONAL ASSOCIATION, as Trustee


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

Dated: __________________


                                      A-2
<PAGE>
                              [REVERSE OF SECURITY]

                                 ANTIGENICS INC.

                     5.25% CONVERTIBLE SENIOR NOTE DUE 2025

      1. INTEREST. Antigenics Inc., a Delaware corporation (the "COMPANY"),
promises to pay interest on the principal amount of this Security at the rate
per annum shown above. The Company will pay interest, payable semi-annually in
arrears, on February 1 and August 1 of each year, with the first payment to be
made on August 1, 2005. Interest on the Securities will accrue on the principal
amount from, and including, the most recent date to which interest has been paid
or provided for or, if no interest has been paid or provided for, from, and
including, January 25, 2005, in each case to, but excluding, the next interest
payment date or Maturity Date, as the case may be. Interest will be computed on
the basis of a 360-day year of twelve 30-day months.

      2. MATURITY. The Securities will mature on February 1, 2025.

      3. METHOD OF PAYMENT. Except as provided in the Indenture (as defined
below), the Company will pay interest on the Securities to the persons who are
Holders of record of Securities at the close of business on the record date set
forth on the face of this Security next preceding the applicable interest
payment date. Holders must surrender Securities to a Paying Agent to collect the
principal amount, Redemption Price, Option Purchase Price or Fundamental Change
Repurchase Price of the Securities, plus, if applicable, accrued and unpaid
interest, if any, payable as herein provided upon Redemption, Purchase at
Holder's Option or Repurchase Upon Fundamental Change, as the case may be. The
Company will pay, in money of the United States that at the time of payment is
legal tender for payment of public and private debts, all amounts due in cash
with respect to the Securities, which amounts shall be paid (A) in the case this
Security is in global form, by wire transfer of immediately available funds to
the account specified by the Holder hereof; or (B) in the case this Security is
held, other than global form, by a Holder who is the record holder of more than
five million dollars ($5,000,000) aggregate principal amount of Securities, by
wire transfer of immediately available funds to the account specified by such
Holder or, if no such account is specified, or if this Security is held, other
than in global form, by a Holder who is the record holder of five million
dollars ($5,000,000) or less in aggregate principal amount of Securities, by
mailing a check to such Holder's address shown in the register of the Registrar.

      4. PAYING AGENT, REGISTRAR, CONVERSION AGENT. Initially, HSBC Bank USA,
National Association (the "TRUSTEE"), will act as Paying Agent, Registrar and
Conversion Agent. The Company may change any Paying Agent, Registrar or
Conversion Agent without notice.

      5. INDENTURE. The Company issued the Securities under an Indenture dated
as of January 25, 2005 (the "INDENTURE") between the Company and the Trustee.
The terms of the Securities include those stated in the Indenture and those made
part of the Indenture by reference to the Trust Indenture Act of 1939 (15 U.S.
Code Sections 77aaa-77bbbb) (the "TIA") as amended and in effect from time
to time. The Securities are subject to all such terms, and Holders are referred
to the Indenture and the TIA for a statement of such terms. The Securities are
general unsecured senior obligations of the Company limited to $50,000,000
aggregate principal amount


                                      A-3
<PAGE>
($60,000,000 if the Initial Purchasers have elected to exercise in full the
Option to purchase up to an additional $10,000,000 aggregate principal amount of
the Securities), except as otherwise provided in the Indenture (except for
Securities issued in substitution for destroyed, mutilated, lost or stolen
Securities). Terms used herein without definition and which are defined in the
Indenture have the meanings assigned to them in the Indenture.

      6. OPTIONAL REDEMPTION.

            The Company shall have the right, at the Company's option, at any
time, and from time to time, on a Redemption Date on or after February 1, 2012,
to redeem all or any part of the Securities at a price payable in cash equal to
one hundred percent (100%) of the principal amount of the Securities to be
redeemed, plus accrued and unpaid interest, if any, to, but excluding, the
Redemption Date.

            Upon surrender to the Paying Agent of a Security subject to
Redemption, such Security shall be paid, to the Holder surrendering such
Security, at the Redemption Price plus accrued and unpaid interest to, but
excluding, the Redemption Date, unless the Redemption Date is an interest
payment date, in which case such accrued and unpaid interest will instead be
paid on such interest payment date to the Holder of record of such Security at
the close of business on the record date for such interest payment. The Company
will make at least fourteen (14) semi-annual interest payments with respect to
the Securities prior to redeeming any Securities under this paragraph 6.

            If the Paying Agent (other than the Company) holds on a Redemption
Date money sufficient to pay the aggregate Redemption Price with respect to all
Securities to be redeemed, plus accrued and unpaid interest, if any, payable as
provided in the Indenture upon Redemption, then (unless there shall be a Default
in the payment of such aggregate Redemption Price or of such accrued and unpaid
interest) on and after such date such Securities shall be deemed to be no longer
outstanding, interest on such Securities shall cease to accrue, and such
Securities shall be deemed paid whether or not such Securities are delivered to
the Paying Agent. Thereafter, all rights of the Holders of such Securities shall
terminate with respect to such Securities, other than the right to receive the
Redemption Price, plus such accrued and unpaid interest, in accordance with the
Indenture.

      7. NOTICE OF REDEMPTION. Notice of Redemption will be mailed at least
thirty (30) days but not more than sixty (60) days before the Redemption Date to
each Holder of Securities to be redeemed at its address appearing in the
security register. Securities in denominations larger than $1,000 principal
amount may be redeemed in part but only in integral multiples of $1,000
principal amount.

      8. PURCHASE BY THE COMPANY AT THE OPTION OF THE HOLDER. Subject to the
terms and conditions of the Indenture, the Company shall become obligated to
purchase, at the option of the Holder, the Securities held by such Holder on
February 1, 2012, February 1, 2015 and February 1, 2020 (each, an "OPTION
PURCHASE DATE") at an Option Purchase Price, payable in cash, equal to one
hundred percent (100%) of the principal amount of the Securities to be
purchased, plus accrued and unpaid interest, if any, to, but excluding, the
applicable Option Purchase Date, upon delivery of a Purchase Notice containing
the information set forth in the


                                      A-4
<PAGE>
Indenture, at any time from 9:00 a.m., New York City time, on the date that is
twenty (20) Business Days prior to the applicable Option Purchase Date until
5:00 p.m., New York City time, on the third (3rd) Business Day immediately
preceding the applicable Option Purchase Date and upon delivery of the
Securities to the Paying Agent by the Holder as set forth in the Indenture.

      Holders have the right to withdraw any Purchase Notice by delivering to
the Paying Agent a written notice of withdrawal in accordance with the
provisions of the Indenture.

            If the Paying Agent (other than the Company) holds on an Option
Purchase Date money sufficient to pay the aggregate Option Purchase Price with
respect to all Securities to be purchased upon Purchase at Holder's Option, plus
accrued and unpaid interest, if any, payable as provided in the Indenture upon
Purchase at Holder's Option, then (unless there shall be a Default in the
payment of such aggregate Option Purchase Price or of such accrued and unpaid
interest) on and after such date such Securities shall be deemed to be no longer
outstanding, interest on such Securities shall cease to accrue, and such
Securities shall be deemed paid whether or not such Securities are delivered to
the Paying Agent. Thereafter, all rights of the Holders of such Securities shall
terminate with respect to such Securities, other than the right to receive the
Option Purchase Price, plus such accrued and unpaid interest, in accordance with
the Indenture.

      9. REPURCHASE AT OPTION OF HOLDER UPON A FUNDAMENTAL CHANGE. Subject to
the terms and conditions of the Indenture, in the event of a Fundamental Change,
each Holder of the Securities shall have the right, at the Holder's option, to
require the Company to repurchase such Holder's Securities including any portion
thereof which is $1,000 in principal amount or any integral multiple thereof on
a date selected by the Company (the "FUNDAMENTAL CHANGE REPURCHASE DATE"), which
date is no later than thirty (30) days after the date on which notice of such
Fundamental Change is mailed in accordance with the Indenture, at a price
payable in cash equal to one hundred percent (100%) of the principal amount of
such Security, plus accrued and unpaid interest to, but excluding, the
Fundamental Change Repurchase Date.

            Within thirty (30) days after the occurrence of the Fundamental
Change, the Company must mail, or cause to be mailed, notice of the occurrence
of such Fundamental Change to each Holder at the address of such Holder
appearing in the register of the Registrar. Such notice shall include, among
other things, a description of the procedure which a Holder must follow to
exercise the Fundamental Change Repurchase Right. To exercise the Fundamental
Change Repurchase Right, a Holder of Securities must, in accordance with the
provisions of the Indenture, (i) deliver, no later than 5:00 p.m., New York City
time, on the third (3rd) Business Day immediately preceding the Fundamental
Change Repurchase Date, a Purchase Notice to the Company (if it is acting as its
own Paying Agent) or to the Paying Agent; and (ii) deliver, at any time after
the delivery of such Purchase Notice, the Securities with respect to which the
Holder is exercising its Fundamental Change Repurchase Right (together with all
necessary endorsements). If the Securities delivered in connection with a
Holder's exercise of its Fundamental Change Repurchase Right are held in
book-entry form through the Depositary, then such Purchase Notice must comply
with applicable procedures of the Depositary.

      10. CONVERSION.


                                      A-5
<PAGE>
            Subject to earlier Redemption, Purchase at Holder's Option or
Repurchase Upon Fundamental Change, Holders may surrender Securities in integral
multiples of $1,000 principal amount for conversion into shares of Common Stock
in accordance with Article X of the Indenture at any time prior to stated
maturity.

            To convert a Security, a Holder must (1) complete and sign the
Conversion Notice, with appropriate signature guarantee, on the back of the
Security, (2) surrender the Security to a Conversion Agent, (3) furnish
appropriate endorsements and transfer documents if required by the Registrar or
Conversion Agent, (4) pay the amount of interest, if any, the Holder must pay in
accordance with the Indenture and (5) pay any tax or duty if required pursuant
to the Indenture. A Holder may convert a portion of a Security if the portion is
$1,000 principal amount or an integral multiple of $1,000 principal amount.

            The initial Conversion Rate is 92.9023 shares of Common Stock per
$1,000 principal amount of Securities (which results in an effective initial
Conversion Price of approximately $10.76 per share) subject to adjustment in the
event of certain circumstances as specified in the Indenture. The Company will
deliver a check in lieu of any fractional share. Except as other otherwise
provided herein or in the Indenture, on conversion, no payment or adjustment for
any unpaid and accrued interest on, or additional interest with respect to, the
Securities will be made. If a Holder surrenders a Security for conversion after
the close of business on the record date for the payment of an installment of
interest and prior to the related interest payment date, such Security, when
surrendered for conversion, must be accompanied by cash payment of an amount
equal to the interest thereon which the registered Holder at the close of
business on such record date is to receive (other than overdue interest, if any,
that has accrued on such Security), unless such Security has been called for
Redemption as described in the Indenture.

            The Conversion Rate applicable to each Security that is surrendered
for conversion, in accordance with the Securities and Article X of the
Indenture, at any time from, and including, the date that is fifteen (15)
Business Days prior to the date originally announced by the Company as the
anticipated effective date of a Make-Whole Fundamental Change until, and
including, the date that is fifteen (15) Business Days after the actual
effective date of such Make-Whole Fundamental Change shall be increased to an
amount equal to the Conversion Rate that would, but for Section 10.15 of the
Indenture, otherwise apply to such Security pursuant to Article X of the
Indenture, plus an amount equal to the Make-Whole Conversion Rate Adjustment;
provided, however, that such increase to the Conversion Rate shall not apply if
(i) such Make-Whole Fundamental Change constitutes a Public Acquirer Fundamental
with respect to which the Company shall have duly made, and given full effect
to, an election, pursuant to and in accordance with Section 10.15(F) of the
Indenture, to make an Acquirer Stock Conversion Right Adjustment; or (ii) such
Make-Whole Fundamental Change is announced by the Company but shall not be
consummated.

            Any shares of Common Stock that are issued upon conversion of a
Security shall bear the Private Placement Legend until after the second
anniversary of the later of the Issue Date and the last date on which the
Company or any Affiliate was the owner of such shares or the Security (or any
predecessor security) from which such shares were converted (or such shorter
period of time as permitted by Rule 144(k) under the Securities Act or any
successor


                                      A-6
<PAGE>
provision thereunder) (or such longer period of time as may be required under
the Securities Act or applicable state securities laws, as set forth in an
Opinion of Counsel, unless otherwise agreed by the Company and the Holder
thereof).

      11. DENOMINATIONS, TRANSFER, EXCHANGE. The Securities are in registered
form, without coupons, in denominations of $1,000 principal amount and integral
multiples of $1,000 principal amount. The transfer of Securities may be
registered and Securities may be exchanged as provided in the Indenture. The
Registrar may require a Holder, among other things, to furnish appropriate
endorsements and transfer documents. No service charge shall be made for any
such registration of transfer or exchange, but the Company may require payment
of a sum sufficient to cover any tax or similar governmental charge that may be
imposed in connection with certain transfers or exchanges. The Company or the
Trustee, as the case may be, shall not be required to register the transfer of
or exchange any Security (i) during a period beginning at the opening of
business fifteen (15) days before the mailing of a notice of redemption of the
Securities selected for Redemption under Section 3.04 of the Indenture and
ending at the close of business on the day of such mailing or (ii) for a period
of fifteen (15) days before selecting, pursuant to Section 3.03 of the
Indenture, Securities to be redeemed or (iii) that has been selected for
Redemption or for which a Purchase Notice has been delivered, and not withdrawn,
in accordance with the Indenture, except the unredeemed or unrepurchased portion
of Securities being redeemed or repurchased in part.

      12. PERSONS DEEMED OWNERS. The registered Holder of a Security may be
treated as the owner of such Security for all purposes.

      13. MERGER OR CONSOLIDATION. Except as provided in the Indenture, the
Company shall not consolidate with, or merge with or into, or sell, transfer,
lease, convey or otherwise dispose of all or substantially all of the property
or assets of the Company to, another person, whether in a single transaction or
series of related transactions, unless (A) either (i) such transaction or series
of transactions shall be a merger or consolidation where the Company shall be
the surviving corporation; or (ii) the surviving, resulting or transferee person
both (a) is a corporation organized and existing under the laws of the United
States, any State thereof or the District of Columbia; and (b) assumes by
supplemental indenture all the obligations of the Company under the Securities
and the Indenture; and (B) immediately after giving effect to such transaction
or series of transactions, no Default or Event of Default shall exist.

      14. AMENDMENTS, SUPPLEMENTS AND WAIVERS. Subject to certain exceptions,
the Indenture or the Securities may be amended or supplemented with the consent
of the Holders of at least a majority in aggregate principal amount of the
outstanding Securities, and certain existing Defaults or Events of Default may
be waived with the consent of the Holders of a majority in aggregate principal
amount of the Securities then outstanding. In accordance with the terms of the
Indenture, the Company, with the consent of the Trustee, may amend or supplement
this Indenture or the Securities without notice to or the consent of any
Securityholder: (i) to comply with Sections 5.01 and 10.12 of the Indenture and,
in accordance with Section 10.15(F) of the Indenture, to give effect to an
election, pursuant to such Section 10.15(F), by the Company to make an Acquirer
Stock Conversion Right Adjustment with respect to a Public Acquirer Fundamental
Change; (ii) to make any changes or modifications to the Indenture necessary in
connection with the registration of the Securities under the Securities Act


                                      A-7
<PAGE>
pursuant to the Registration Rights Agreement or the qualification of the
Indenture under the TIA; (iii) to secure the obligations of the Company in
respect of the Securities; (iv) to add to the covenants of the Company described
in the Indenture for the benefit of Securityholders or to surrender any right or
power conferred upon the Company; (v) to make provisions with respect to
adjustments to the Conversion Rate as required by the Indenture or to increase
the Conversion Rate in accordance with the Indenture; (vi) to add additional
events which shall constitute an Event of Default under the Indenture; and (vii)
to provide for a successor Trustee in accordance with the Indenture. In
addition, the Company and the Trustee may enter into a supplemental indenture
without the consent of Holders of the Securities to cure any ambiguity, defect,
omission or inconsistency in the Indenture in a manner that does not
individually or in the aggregate adversely affect the rights of any Holder in
any material respect.

      15. DEFAULTS AND REMEDIES. Subject to the provisions of the Indenture, an
"EVENT OF DEFAULT" occurs if (i) the Company defaults in the payment of the
principal of, or premium, if any, on, any Security when the same becomes due and
payable, whether at maturity, upon Redemption, on an Option Purchase Date with
respect to a Purchase at Holder's Option, on a Fundamental Change Repurchase
Date with respect to a Repurchase Upon Fundamental Change or otherwise; (ii) the
Company defaults in the payment of an installment of interest or additional
interest, on any Security when due, if such failure continues for thirty (30)
days after the date when due; (iii) the Company fails to satisfy its conversion
obligations upon exercise of a Holder's conversion rights pursuant to the
Indenture; (iv) the Company fails to timely provide a Fundamental Change Notice,
or an Option Purchase Notice, as required by the provisions of the Indenture;
(v) the Company fails to comply with any other term, covenant or agreement set
forth in the Securities or the Indenture and such failure continues for the
period, and after the notice, specified in the Indenture; (vi) the Company or
any of its Subsidiaries defaults in the payment when due, after the expiration
of any applicable grace period, of principal of, or premium, if any, or interest
on, Indebtedness of the Company or any Subsidiary for money borrowed, in the
aggregate principal amount then outstanding of ten million dollars ($10,000,000)
or more, or the acceleration of Indebtedness of the Company or any of its
Subsidiaries for money borrowed in such aggregate principal amount or more so
that it becomes due and payable prior to the date on which it would otherwise
become due and payable and such default is not cured or waived, or such
acceleration is not rescinded, within sixty (60) days after notice to the
Company by the Trustee or to the Company and the Trustee by Holders of at least
twenty five percent (25%) in the aggregate principal amount of the Securities
then outstanding, each in accordance with the Indenture; or (vii) there occur
certain events of bankruptcy or insolvency involving the Company or any of its
Significant Subsidiaries or any group of Subsidiaries that in the aggregate
would constitute a Significant Subsidiary of the Company.

      If an Event of Default (excluding an Event of Default specified in Section
6.01(vii) or (viii) of the Indenture with respect to the Company (but including
an Event of Default specified in Section 6.01(vii) or (viii) of the Indenture
solely with respect to a Significant Subsidiary of the Company or any group of
Subsidiaries that in the aggregate would constitute a Significant Subsidiary of
the Company)) occurs and is continuing, the Trustee by notice to the Company or
the Holders of at least twenty five percent (25%) in principal amount of the
Securities then outstanding by notice to the Company and the Trustee may declare
the Securities to be due and payable. Upon such declaration, the principal of,
and any premium and accrued and unpaid interest (including any additional
interest) on, all Securities shall be due and


                                      A-8
<PAGE>
payable immediately. If an Event of Default specified in Section 6.01(vii) or
(viii) of the Indenture with respect to the Company (excluding, for purposes of
this sentence, an Event of Default specified in Section 6.01(vii) or (viii) of
the Indenture solely with respect to a Significant Subsidiary of the Company or
any group of Subsidiaries that in the aggregate would constitute a Significant
Subsidiary of the Company) occurs, the principal of, and premium and accrued and
unpaid interest (including any additional interest) on, all the Securities shall
ipso facto become and be immediately due and payable without any declaration or
other act on the part of the Trustee or any Holder. The Holders of a majority in
aggregate principal amount of the Securities then outstanding by written notice
to the Trustee may rescind or annul an acceleration and its consequences if (A)
the rescission would not conflict with any governmental or court order or
decree, (B) all existing Events of Default, except the nonpayment of principal,
premium or interest that has become due solely because of the acceleration, have
been cured or waived and (C) all amounts due to the Trustee under Section 7.07
of the Indenture have been paid.

            Holders may not enforce the Indenture or the Securities except as
provided in the Indenture. The Holders of a majority in aggregate principal
amount of the Securities then outstanding may 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 it. However, the Trustee may refuse
to follow any direction that conflicts with law or the Indenture, is unduly
prejudicial to the rights of other Holders or would involve the Trustee in
personal liability unless the Trustee is offered indemnity reasonably
satisfactory to it ; provided, that the Trustee may take any other action deemed
proper by the Trustee which is not inconsistent with such direction.

            If a Default or Event of Default occurs and is continuing as to
which the Trustee has received notice pursuant to the provisions of the
Indenture, or as to which a Responsible Officer of the Trustee shall have actual
knowledge, then the Trustee shall mail to each Holder a notice of the Default or
Event of Default within thirty (30) days after the Trustee has received such
notice or after such Responsible Officer shall have acquired such actual
knowledge, whichever is earlier, unless such Default or Event of Default has
been cured or waived; provided, however, that, except in the case of a Default
or Event of Default in payment of any amounts due with respect to any Security,
the Trustee may withhold such notice if, and so long as it in good faith
determines that, withholding such notice is in the best interests of Holders.
The Company must deliver to the Trustee an annual compliance certificate.

      16. REGISTRATION RIGHTS. The Holders are entitled to registration rights
as set forth in the Registration Rights Agreement. The Holders shall be entitled
to receive additional interest in certain circumstances, all as set forth in the
Registration Rights Agreement.

      17. TRUSTEE DEALINGS WITH THE COMPANY. The Trustee under the Indenture, or
any banking institution serving as successor Trustee thereunder, in its
individual or any other capacity, may make loans to, accept deposits from, and
perform services for, the Company or its Affiliates, and may otherwise deal with
the Company or its Affiliates, as if it were not Trustee.

      18. NO RECOURSE AGAINST OTHERS. No past, present or future director,
officer, employee or stockholder, as such, of the Company shall have any
liability for any obligations of the Company under the Securities or the
Indenture or for any claim based on, in respect of, or by


                                      A-9
<PAGE>
reason of, such obligations or their creation. Each Holder, by accepting a
Security, waives and releases all such liability. The waiver and release are
part of the consideration for the issue of the Securities.

      19. AUTHENTICATION. This Security shall not be valid until authenticated
by the manual signature of the Trustee or an authenticating agent in accordance
with the Indenture.

      20. ABBREVIATIONS. Customary abbreviations may be used in the name of a
Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT (=
tenants by the entirety), JT TEN (= joint tenants with right of survivorship and
not as tenants in common), CUST (= Custodian), and U/G/M/A (Uniform Gifts to
Minors Act).

      THE COMPANY WILL FURNISH TO ANY HOLDER UPON WRITTEN REQUEST AND WITHOUT
CHARGE A COPY OF THE INDENTURE. REQUESTS MAY BE MADE TO:

                                 Antigenics Inc.
                                630 Fifth Avenue
                                   Suite 2100
                               New York, NY 10111


                                      A-10
<PAGE>
                              [FORM OF ASSIGNMENT]

I or we assign to
PLEASE INSERT SOCIAL SECURITY OR
OTHER IDENTIFYING NUMBER


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

--------------------------------------------------------------------------------
(please print or type name and address)

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

--------------------------------------------------------------------------------
the within Security and all rights thereunder, and hereby irrevocably constitute
and appoint

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

Attorney to transfer the Security on the books of the Company with full power of
substitution in the premises.

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

                                          NOTICE: The signature on this
                                          assignment must correspond with the
                                          name as it appears upon the face of
                                          the within Security in every
                                          particular without alteration or
                                          enlargement or any change whatsoever
                                          and be guaranteed by a guarantor
                                          institution participating in the
                                          Securities Transfer Agents Medallion
                                          Program or in such other guarantee
                                          program acceptable to the Trustee.


Signature Guarantee:
                    ------------------------------------------------------------


                                      A-11
<PAGE>
In connection with any transfer of this Security occurring prior to the date
which is the earlier of (i) the date of the declaration by the SEC of the
effectiveness of a registration statement under the Securities Act of 1933, as
amended, covering resales of this Security (which effectiveness shall not have
been suspended or terminated at the date of the transfer) and (ii) the Resale
Restriction Termination Date, the undersigned confirms that it is making, and it
has not utilized any general solicitation or general advertising in connection
with, the transfer:

                                   [Check One]

(1) ____ to the Company or any Subsidiary thereof, or

(2) ____ pursuant to, and in compliance with, the exemption from registration
         provided by Rule 144A under the Securities Act of 1933, as amended, or

(3) ____ pursuant to, and in compliance with, the exemption from registration
         provided by Rule 144 under the Securities Act of 1933, as amended, or

(4) ____ pursuant to, and in compliance with, an exemption from registration
         under the Securities Act of 1933, as amended, other than Rule 144A or
         Rule 144, or

(5) ____ pursuant to an effective registration statement under the Securities
         Act of 1933, as amended,

and, unless the box below is checked, the undersigned confirms that this
Security is not being transferred to an "affiliate" of the Company (an
"Affiliate") as defined in Rule 144 under the Securities Act of 1933, as
amended:

      [ ] The transferee is an Affiliate of the Company. (If the Security is
transferred to an Affiliate, the restrictive legend must remain on the Security
for at least two (2) years following the date of the transfer.)

Unless one of the items (1) through (5) is checked, the Trustee will refuse to
register any of the Securities evidenced by this certificate in the name of any
person other than the registered Holder thereof; provided, however, that if item
(3) or (4) is checked, the Company or the Trustee may require, prior to
registering any such transfer of the Securities, in their sole discretion, such
written legal opinions, certifications and other information as the Trustee or
the Company have reasonably requested to confirm that such transfer is being
made pursuant to an exemption from, or in a transaction not subject to, the
registration requirements of the Securities Act of 1933, as amended. If item (2)
is checked, the purchaser must complete the certification below.

If none of the foregoing items are checked, the Trustee or Registrar shall not
be obligated to register this Security in the name of any person other than the
Holder hereof unless and until the conditions to any such transfer of
registration set forth herein and in the Indenture shall have been satisfied.

Dated:                                  Signed:
       ------------------------------           --------------------------------
                                                (Sign exactly as name appears on
                                                the other side of this Security)

Signature Guarantee:
                    ------------------------------------------------------------


                                      A-12
<PAGE>
TO BE COMPLETED BY PURCHASER IF (2) ABOVE IS CHECKED

The undersigned represents and warrants that it is purchasing this Security for
its own account or an account with respect to which it exercises sole investment
discretion and that it and any such account is a "qualified institutional buyer"
within the meaning of Rule 144A under the Securities Act of 1933, as amended,
and is aware that the sale to it is being made in reliance on Rule 144A and
acknowledges that it has received such information regarding the Company as the
undersigned has requested pursuant to Rule 144A and acknowledges that the
transferor is relying upon the undersigned's foregoing representations in order
to claim the exemption from registration provided by Rule 144A.

Dated:
       ------------------------------   ----------------------------------------
                                        NOTICE: To be executed by an executive
                                                officer


                                      A-13
<PAGE>
                                CONVERSION NOTICE

To convert this Security in accordance with the Indenture, check the box: [ ]

To convert only part of this Security, state the principal amount to be
converted (must be in multiples of $1,000):


                               $
                                ------------------

If you want the stock certificate made out in another person's name, fill in the
form below:


--------------------------------------------------------------------------------
(Insert other person's soc. sec. or tax I.D. no.)

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

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

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

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

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

Date:                 Signature(s):
     --------------                ---------------------------------------------
                                   (Sign exactly as your name(s) appear(s) on
                                   the other side of this Security)


Signature(s) guaranteed by:
                            ----------------------------------------------------
                            (All signatures must be guaranteed by a guarantor
                            institution participating in the Securities Transfer
                            Agents Medallion Program or in such other guarantee
                            program acceptable to the Trustee.)


                                      A-14
<PAGE>
                                 PURCHASE NOTICE


Certificate No. of Security:  ___________

      If you want to elect to have this Security purchased by the Company
pursuant to Section 3.08 of the Indenture, check the box: [ ]

      If you want to elect to have this Security purchased by the Company
pursuant to Section 3.09 of the Indenture, check the box: [ ]

      If you want to elect to have only part of this Security purchased by the
Company pursuant to Sections 3.08 or 3.09 of the Indenture, as applicable, state
the principal amount to be so purchased by the Company:

                      $
                        ----------------------------------
                        (in an integral multiple of $1,000)

Date:                                   Signature(s):
     -----------------------                         ---------------------------


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


Signature(s) guaranteed by:
                                        ----------------------------------------

                                        (All signatures must be guaranteed by a
                                        guarantor institution participating in
                                        the Securities Transfer Agents Medallion
                                        Program or in such other guarantee
                                        program acceptable to the Trustee.)


                                      A-15
<PAGE>
                                   SCHEDULE A

           SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL SECURITY(a)


      The following exchanges of a part of this Global Security for an interest
in another Global Security or for Securities in certificated form, have been
made:


<TABLE>
<CAPTION>
                                                                          Principal amount of
                           Amount of decrease    Amount of Increase in        this Global           Signature or
                           in Principal amount    Principal amount of     Security following    authorized signatory
                             of this Global       this Global Security       such decrease       of Trustee or Note
    Date of Exchange            Security                                      or increase             Custodian
<S>                        <C>                   <C>                      <C>                   <C>

</TABLE>


---------------
(a) This is included in Global Securities only.


                                      A-16
<PAGE>
                                                                     EXHIBIT B-1


                        FORM OF PRIVATE PLACEMENT LEGEND


THIS SECURITY AND THE COMMON STOCK ISSUABLE UPON CONVERSION OF THIS SECURITY
HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
"SECURITIES ACT") OR ANY STATE SECURITIES LAWS, AND MAY NOT BE OFFERED, SOLD,
PLEDGED OR OTHERWISE TRANSFERRED EXCEPT IN ACCORDANCE WITH THE FOLLOWING
SENTENCE. BY ITS ACQUISITION HEREOF OR OF A BENEFICIAL INTEREST HEREIN, THE
ACQUIRER:

(1) REPRESENTS THAT IT AND ANY ACCOUNT FOR WHICH IT IS ACTING IS A "QUALIFIED
INSTITUTIONAL BUYER" (WITHIN THE MEANING OF RULE 144A UNDER THE SECURITIES ACT)
AND THAT IT EXERCISES SOLE INVESTMENT DISCRETION WITH RESPECT TO EACH SUCH
ACCOUNT, AND

(2) AGREES THAT IT WILL NOT DIRECTLY OR INDIRECTLY ENGAGE IN ANY HEDGING
TRANSACTIONS INVOLVING THIS SECURITY OR THE COMMON STOCK ISSUABLE UPON
CONVERSION OF THIS SECURITY UNLESS IN COMPLIANCE WITH THE SECURITIES ACT, AND

(3) AGREES FOR THE BENEFIT OF THE COMPANY THAT IT WILL NOT OFFER, SELL, PLEDGE
OR OTHERWISE TRANSFER THIS SECURITY OR THE COMMON STOCK ISSUABLE UPON CONVERSION
OF THIS SECURITY, OR ANY BENEFICIAL INTEREST HEREIN OR THEREIN, PRIOR TO THE
DATE THAT IS THE LATER OF (X) TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUE
DATE HEREOF AND THE LAST DATE ON WHICH THE COMPANY OR ANY AFFILIATE OF THE
COMPANY WAS THE OWNER OF THIS SECURITY (OR ANY PREDECESSOR OF THIS SECURITY) OR
SUCH SHORTER PERIOD OF TIME AS PERMITTED BY RULE 144(K) UNDER THE SECURITIES ACT
OR ANY SUCCESSOR PROVISION THEREUNDER, AND (Y) SUCH LATER DATE, IF ANY, AS MAY
BE REQUIRED BY APPLICABLE LAW, EXCEPT ONLY:

      (A)   TO THE COMPANY OR ANY SUBSIDIARY THEREOF, OR

      (B)   PURSUANT TO A REGISTRATION STATEMENT WHICH HAS BECOME EFFECTIVE
            UNDER THE SECURITIES ACT, OR

      (C)   TO A QUALIFIED INSTITUTIONAL BUYER IN COMPLIANCE WITH RULE 144A
            UNDER THE SECURITIES ACT, OR

      (D)   PURSUANT TO AN EXEMPTION FROM REGISTRATION PROVIDED BY RULE 144
            UNDER THE SECURITIES ACT OR ANY OTHER AVAILABLE EXEMPTION FROM THE
            REGISTRATION REQUIREMENTS OF THE SECURITIES ACT.

PRIOR TO THE REGISTRATION OF ANY TRANSFER IN ACCORDANCE WITH (3)(C) ABOVE, A
DULY COMPLETED AND SIGNED CERTIFICATE (THE FORM OF WHICH MAY BE OBTAINED FROM
THE TRUSTEE) MUST BE DELIVERED TO THE TRUSTEE. PRIOR TO THE REGISTRATION OF ANY
TRANSFER IN ACCORDANCE WITH (3)(D) ABOVE, THE COMPANY AND THE TRUSTEE RESERVE
THE RIGHT TO REQUIRE THE DELIVERY OF SUCH LEGAL OPINIONS, CERTIFICATIONS OR
OTHER EVIDENCE AS MAY REASONABLY BE REQUIRED IN ORDER TO DETERMINE THAT THE
PROPOSED TRANSFER IS BEING MADE IN COMPLIANCE WITH THE SECURITIES ACT AND
APPLICABLE STATE SECURITIES LAWS. NO REPRESENTATION IS MADE AS TO THE


                                     B-1-1
<PAGE>
AVAILABILITY OF ANY EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE
SECURITIES ACT.

THIS SECURITY SHALL BE ENTITLED TO THE BENEFITS OF THAT CERTAIN REGISTRATION
RIGHTS AGREEMENT, DATED JANUARY 25, 2005, AMONG ANTIGENICS INC. AND THE OTHER
PARTIES THERETO.


                                     B-1-2
<PAGE>
                                                                     EXHIBIT B-2

                       FORM OF LEGEND FOR GLOBAL SECURITY


      Any Global Security authenticated and delivered hereunder shall bear a
legend (which would be in addition to any other legends required in the case of
a Restricted Security) in substantially the following form:

            THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE
      INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A
      DEPOSITARY OR A NOMINEE OF A DEPOSITARY OR A SUCCESSOR DEPOSITARY. THIS
      SECURITY IS NOT EXCHANGEABLE FOR SECURITIES REGISTERED IN THE NAME OF A
      PERSON OTHER THAN THE DEPOSITARY OR ITS NOMINEE EXCEPT IN THE LIMITED
      CIRCUMSTANCES DESCRIBED IN THE INDENTURE, AND NO TRANSFER OF THIS SECURITY
      (OTHER THAN A TRANSFER OF THIS SECURITY AS A WHOLE BY THE DEPOSITARY TO A
      NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE
      DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY) MAY BE REGISTERED EXCEPT
      IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE.

            UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
      OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
      COMPANY 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.

            TRANSFERS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS IN
      WHOLE, BUT NOT IN PART, TO NOMINEES OF CEDE & CO. OR TO A SUCCESSOR
      THEREOF OR SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS
      GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
      RESTRICTIONS SET FORTH IN SECTION 2.16 OF THE INDENTURE.


                                     B-2-1
<PAGE>
                                                                       EXHIBIT C

          Form of Notice of Transfer Pursuant to Registration Statement


Antigenics Inc.
630 Fifth Avenue
Suite 2100
New York, NY 10111
Attention: General Counsel

HSBC Bank USA, National Association
Issuer Services
452 Fifth Avenue
New York, NY 10018
Attention: Mr. Frank J. Godino


      Re:   Antigenics Inc. (the "COMPANY") 5.25% Convertible Senior Notes due
            2025 (the "SECURITIES")

Ladies and Gentlemen:


      Please be advised that _____________ has transferred $___________
aggregate principal amount of the Securities and ________ shares of the Common
Stock, $0.01 par value per share, of the Company issued on conversion of the
Securities ("STOCK") pursuant to an effective Shelf Registration Statement on
Form S-3 (File No. 333-________).

      We hereby certify that the prospectus delivery requirements, if any, of
the Securities Act of 1933 as amended, have been satisfied with respect to the
transfer described above and that the above-named beneficial owner of the
Securities or Stock is named as a "Selling Security Holder" in the Prospectus
dated _________, or in amendments or supplements thereto, and that the aggregate
principal amount of the Securities and the number of shares of Stock transferred
are [a portion of] the Securities and Stock listed in such Prospectus, as
amended or supplemented, opposite such owner's name.


                                        Very truly yours,



                                        ----------------------------------------
                                                        (Name)


                                       C-1
<PAGE>
                                                                       EXHIBIT D


    Form of Opinion of Counsel in Connection with Registration of Securities


HSBC Bank USA, National Association
Issuer Services
452 Fifth Avenue
New York, NY 10018
Attention: Mr. Frank J. Godino

      Re:   Antigenics Inc. (the "COMPANY") 5.25% Convertible Senior Notes due
            2025 (the "SECURITIES")

Ladies and Gentlemen:


      Reference is made to the Securities issued pursuant to a certain Indenture
dated as of January 25, 2005 by and between the Company and HSBC Bank USA,
National Association, as trustee (the "TRUSTEE"). The Company issued $50,000,000
principal amount of Securities on January 25, 2005 [and an additional
$_____________ on ___________ [IF THE INITIAL PURCHASERS' OPTION IS EXERCISED]]
in transactions exempt from registration under the Securities Act of 1933, as
amended (the "SECURITIES ACT"). The Company has filed with the Securities and
Exchange Commission (the "SEC") [a] [Amendment No. [_] to the] Registration
Statement on Form S-3 (File No. 333-______) (the "REGISTRATION STATEMENT")
relating to the registration under the Securities Act of $______________
principal amount of the Securities and the shares of Common Stock of the Company
(the "SHARES") issuable upon conversion of the Securities being registered. The
Registration Statement was declared effective by order of the SEC dated _______.


      We have acted as counsel for the Company in connection with the issuance
of the Securities and the preparation and filing of the Registration Statement
and are familiar with the Securities, the Indenture, the Registration Statement,
the above-mentioned SEC order and such other documents as are necessary to
render this opinion.

      Based on the foregoing, it is our opinion that (1) the Registration
Statement has become effective under the Securities Act and, to our knowledge,
no stop order suspending the effectiveness of the Registration Statement has
been issued, (2) assuming that the Securities covered by the Registration
Statement and the Shares issuable upon conversion of such Securities are sold by
the Holder or Holders identified in the Registration Statement in a manner
specified in the Registration Statement, such sale or sales of the Securities
and Shares issuable upon conversion of the Securities will have been duly
registered under the Securities Act and (3) the Indenture has been duly
qualified under the Trust Indenture Act of 1939, as amended.

Yours truly,


                                      D-1