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                                                                  Exhibit 4.01
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                            CETUS CORPORATION

                                    TO

                          BANKERS TRUST COMPANY,
                                        TRUSTEE

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

                                INDENTURE
                         Dated as of May 21, 1987

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

                             U.S. $100,000,000
           5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES
                                DUE 2002

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                            TABLE OF CONTENTS

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PARTIES...................................................        1
RECITALS OF THE COMPANY...................................        1


                              ARTICLE ONE

                  Definitions and Other Provisions of
                          General Application

Section 101. Definitions:
             Act..........................................        2
             Affiliate; control...........................        2
             Authenticating Agent.........................        2
             Authorized Newspaper.........................        2
             Bearer Security..............................        2
             Board of Directors...........................        3
             Board Resolution.............................        3
             Business Day.................................        3
             Closing Market Price Per Share...............        3
             Common Stock.................................        3
             Company......................................        4
             Company Request; Company Order...............        4
             Conversion Agent.............................        4
             Conversion Price.............................        4
             Converted Securities.........................        4
             Corporate Trust Office.......................        4
             corporation..................................        4
             coupon.......................................        4
             Defaulted Interest...........................        4
             Dollar; U.S.$................................        4
             Event of Default.............................        5
             Exchange Date................................        5
             Global Security..............................        5
             Holder.......................................        5
             Indenture....................................        5
             Interest Payment Date........................        5
             Maturity.....................................        5
             Officers' Certificate........................        5
             Opinion of Counsel...........................        5
             Outstanding..................................        5
             Paying Agent.................................        6
             Paying Agency Agreement......................        7

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NOTE: This table of contents shall not, for any purpose, be deemed part of
      the Indenture.

                                      i
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Section 101. Definitions:
             Person.......................................        7
             Place of Conversion..........................        7
             Place of Payment.............................        7
             Predecessor Security.........................        7
             Principal Office.............................        7
             Principal Paying Agent.......................        7
             Redemption Date..............................        7
             Redemption Price.............................        7
             Registered Security..........................        7
             Regular Record Date..........................        8
             Responsible Officer..........................        8
             Rights.......................................        8
             SBCI.........................................        8
             Security Register; Security Registrar........        8
             Senior Debt..................................        8
             Special Record Date..........................        9
             Stated Maturity..............................        9
             Subsidiary...................................        9
             Transfer Agent...............................        9
             Trustee......................................        9
             United States................................        9
             United States Alien..........................        9
             United States Bank Branch....................        9
             United States Institutional Investor.........        9
             Vice President...............................       10
Section 102. Form of Documents Delivered to Trustee.......       10
Section 103. Acts of Holders of Securities................       10
Section 104. Notices, Etc., to Trustee and Company........       12
Section 105. Notice to Holders of Securities; Waiver......       13
Section 106. Effect of Headings and Table of Contents.....       14
Section 107. Successors and Assigns.......................       14
Section 108. Separability Clause..........................       15
Section 109. Benefits of Indenture........................       15
Section 110. Governing Law; Submission to Jurisdiction....       15
Section 111. Legal Holidays...............................       15

                                ARTICLE TWO

                               Security Forms

Section 201. Forms Generally..............................       17
Section 202. Forms of Definitive Securities...............       17
Section 203. Form of Temporary Global Security............       34
Section 204. Form of Coupon...............................       37
Section 205. Form of Trustee's Certificate of
               Authentication.............................       40
Section 206. Form of Conversion Notice....................       40

                                      ii
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                                ARTICLE THREE

                               The Securities

Section 301. Title and Terms..............................       42
Section 302. Denominations................................       42
Section 303. Execution, Authentication, Delivery and
               Dating.....................................       43
Section 304. Temporary Global Security; Exchange of
               Temporary Global Security for Definitive
               Securities.................................       44
Section 305. Registration, Registration of Transfer and
               Exchange...................................       46
Section 306. Mutilated, Destroyed, Lost or Stolen
               Securities and Coupons.....................       49
Section 307. Payment of Interest; Interest Rights
               Preserved..................................       50
Section 308. Persons Deemed Owners........................       53
Section 309. Cancellation.................................       53
Section 310. Computation of Interest......................       54

                              ARTICLE FOUR

                       Satisfaction and Discharge

Section 401. Satisfaction and Discharge of Indenture......       55
Section 402. Application of Trust Money...................       56

                              ARTICLE FIVE

                                Remedies

Section 501. Events of Default............................       58
Section 502. Acceleration of Maturity; Rescission and
               Annulment..................................       60
Section 503. Collection of Indebtedness and Suits for
               Enforcement by Trustee.....................       61
Section 504. Trustee May File Proofs of Claim.............       62
Section 505. Trustee May Enforce Claims Without
               Possession of Securities or Coupons........       63
Section 506. Application of Money Collected...............       63
Section 507. Limitation on Suits..........................       64
Section 508. Unconditional Right of Holders to Receive
               Principal, Premium and Interest and to
               Convert....................................       65
Section 509. Restoration of Rights and Remedies...........       65
Section 510. Rights and Remedies Cumulative...............       66

                                      iii
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Section 511. Delay or Omission Not Waiver.................       66
Section 512. Control by Holders of Securities.............       66
Section 513. Waiver of Past Defaults......................       67
Section 514. Undertaking for Costs........................       67
Section 515. Waiver of Stay or Extension Laws.............       68

                                  ARTICLE SIX

                                  The Trustee

Section 601. Certain Duties and Responsibilities..........       69
Section 602. Certain Rights of Trustee....................       70
Section 603. Not Responsible for Recitals or Issuance of
               Securities.................................       71
Section 604. May Hold Securities, Act as Trustee Under
               Other Indentures...........................       72
Section 605. Money Held in Trust..........................       72
Section 606. Compensation and Reimbursement...............       72
Section 607. Corporate Trustee Required; Eligibility......       73
Section 608. Resignation and Removal; Appointment of
               Successor..................................       74
Section 609. Acceptance of Appointment by Successor.......       75
Section 610. Merger, Conversion, Consolidation or
               Succession to Business.....................       76
Section 611. Appointment of Authenticating Agent..........       76

                                 ARTICLE SEVEN

                   Consolidation, Merger, Conveyance, Transfer
                                   or Lease

Section 701. Company May Consolidate, Etc., Only on
               Certain Terms..............................       79
Section 702. Successor Substituted........................       80

                                 ARTICLE EIGHT

                            Supplemental Indentures

Section 801. Supplemental Indentures Without Consent of
               Holders....................................       81
Section 802. Supplemental Indentures with Consent of
               Holders....................................       81
Section 803. Execution of Supplemental Indentures.........       83
Section 804. Effect of Supplemental Indentures............       83

                                      iv
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Section 805. Reference in Securities to Supplemental
               Indentures.................................       83
Section 806. Notice of Supplemental Indentures............       83

                                 ARTICLE NINE

                      Meetings of Holders of Securities

Section 901. Purposes for Which Meetings May Be Called....       85
Section 902. Call, Notice and Place of Meetings...........       85
Section 903. Persons Entitled to Vote at Meetings.........       86
Section 904. Quorum; Action...............................       86
Section 905. Determination of Voting Rights; Conduct and
               Adjournment of Meetings....................       87
Section 906. Counting Votes and Recording Action of
               Meetings...................................       88

                                 ARTICLE TEN

                                  Covenants

Section 1001. Payment of Principal, Premium and
                Interest..................................       89
Section 1002. Maintenance of Offices or Agencies..........       89
Section 1003. Money for Security Payments to Be Held in
                Trust.....................................       91
Section 1004. Additional Interest.........................       93
Section 1005. Corporate Existence.........................       94
Section 1006. Maintenance of Properties...................       94
Section 1007. Payment of Taxes and Other Claims...........       95
Section 1008. Statement of Officers as to Default.........       95
Section 1009. Waiver of Certain Covenants.................       95
Section 1010. Waiver of Usury Laws........................       96

                               ARTICLE ELEVEN

                         Redemption of Securities

Section 1101. Right of Redemption.........................       97
Section 1102. Applicability of Article....................       97
Section 1103. Election to Redeem; Notice to Trustee.......       97
Section 1104. Selection by Trustee of Securities to Be
                Redeemed..................................       98
Section 1105. Notice of Redemption........................       99
Section 1106. Deposit of Redemption Price..................     100
Section 1107. Securities Payable on Redemption Date........     100
Section 1108. Registered Securities Redeemed in Part.......     101

                                      v
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                               ARTICLE TWELVE

                           Conversion of Securities

Section 1201. Conversion Privilege and Conversion Price...      103
Section 1202. Exercise of Conversion Privilege............      103
Section 1203. Fractions of Shares.........................      105
Section 1204. Adjustment of Conversion Price..............      105
Section 1205. Notice of Adjustments of Conversion Price...      109
Section 1206. Notice of Certain Corporation Action........      109
Section 1207. Company to Reserve Common Stock.............      111
Section 1208. Taxes on Conversions........................      111
Section 1209. Covenant as to Common Stock.................      111
Section 1210. Cancellation of Converted Securities........      112
Section 1211. Provisions in Case of Consolidation,
                Merger, Sale of Assets or
                Reclassification..........................      112
Section 1212. Responsibility of Trustee for Conversion
                Provisions................................      113

                               ARTICLE THIRTEEN

                          Subordination of Securities

Section 1301. Securities Subordinate to Senior Debt.......      115
Section 1302. Payment Over of Proceeds Upon Dissolution,
                Etc.......................................      115
Section 1303. Prior Payment to Senior Debt Upon
                Acceleration of Securities................      116
Section 1304. No Payment When Senior Debt in Default......      117
Section 1305. Payment Permitted If No Default.............      118
Section 1306. Subrogation to Rights of Holders of Senior
                Debt......................................      118
Section 1307. Provisions Solely to Define Relative
                Rights....................................      119
Section 1308. Trustee to Effectuate Subordination.........      120
Section 1309. No Waiver of Subordination Provisions.......      120
Section 1310. Notice to Trustee...........................      120
Section 1311. Reliance on Judicial Order or Certificate
                of Liquidating Agent......................      121
Section 1312. Trustee Not Fiduciary for Holders of Senior
                Debt......................................      122
Section 1313. Rights of Trustee as Holder of Senior Debt;
                Preservation of Trustee's Rights..........      122
Section 1314. Article Applicable to Paying Agents.........      122

                                      vi
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TESTIMONIUM...............................................      124
SIGNATURES AND SEALS......................................      125
ACKNOWLEDGEMENTS..........................................      126

EXHIBIT A     Form of certificate to be given by Euro-clear
                and CEDEL S.A.
EXHIBIT B     Form of certificate to be given by Account Holders
EXHIBIT C     Form of Investment Letter for U.S. Bank Branch
EXHIBIT D     Form of certificate to be given by SBCI
EXHIBIT E     Form of letter delivered by United States
                Institutional Investors, to be attached to the
                certificate given by SBCI
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                                      vii
<PAGE>

          INDENTURE, dated as of May 21, 1987, between CETUS CORPORATION, a
corporation duly organized and existing under the laws of the State of
Delaware (herein called the "Company"), having its principal office at 1400
Fifty-Third Street, Emeryville, California 94608, and Bankers Trust Company,
a New York State banking corporation having its principal corporate trust and
agency office at Four Albany Street, New York, New York 10015, Trustee
(herein called the "Trustee").

                            Recitals of the Company

          The Company has duly authorized the creation of an issue of its
5 1/4 per cent. Convertible Subordinated Debentures due 2002 (herein called the
"Securities") and the coupons, if any, thereto appertaining, of substantially
the tenor and amount hereinafter set forth, and to provide therefor the
Company has duly authorized the execution and delivery of this Indenture.

          All things necessary to make the Securities and the coupons, if
any, thereto appertaining, when the Securities are executed by the Company
and authenticated and delivered hereunder and duly issued by the Company, the
valid obligations of the Company, and to make this Indenture a valid
agreement of the Company, in accordance with their and its terms, have been
done.

          NOW, THEREFORE, THIS INDENTURE WITNESSETH:

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

                                 ARTICLE ONE

                      Definitions and Other Provisions
                           of General Application

          SECTION 101. DEFINITIONS.

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

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

<PAGE>

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

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

          "Act", when used with respect to any Holder of a Security, has the
meaning specified in Section 103.

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

          "Authenticating Agent" means any Person authorized by the Trustee
pursuant to Section 611.

          "Authorized Newspaper" means a newspaper, in an official language
of the country of publication or in the English language, customarily
published on each Business Day, whether or not published on Saturdays,
Sundays or holidays, and of general circulation in the place in connection
with which the term is used or in the financial community of such place.
Where successive publications are required to be made in Authorized
Newspapers, the successive publications may be made in the same or in
different newspapers in the same city meeting the foregoing requirements and
in each case on any Business Day.

          "Bearer Security" means any Security in the form for Bearer
Securities set forth in Section 202 payable to bearer.

                                      2

<PAGE>

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

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

          "Business Day", when used with respect to any Place of Payment or
Place of Conversion, means each Monday, Tuesday, Wednesday, Thursday and
Friday which is not a day on which banking institutions in that Place of
Payment or Place of Conversion, as the case may be, (or on which banking
institutions in London or New York) are authorized or obligated by law to
close.

          "Closing Market Price Per Share" means, for any trading day, the
last reported sales price regular way of the Common Stock or, in case no such
reported sale takes place on such trading day, the average of the reported
closing bid and asked prices regular way of the Common Stock, in either case
on the New York Stock Exchange or, if the Common Stock is not listed or
admitted to trading on such Exchange, on the principal national securities
exchange within the United States on which the Common Stock is listed or
admitted to trading or, if not listed or admitted to trading on any national
securities exchange within the United States, the average of the closing bid
and asked prices of the Common Stock in the over-the-counter market as
reported by National Association of Securities Dealers' Automated Quotation
System ("NASDAQ") or, if not so reported by NASDAQ, the average of the
closing bid and asked prices of the Common Stock as furnished by any leading
New York Stock Exchange member firm selected from time to time by the Company
for that purpose.

          "Common Stock" includes any stock of any class of the Company which
has no preference in respect of dividends or of amounts payable in the event
of any voluntary or involuntary liquidation, dissolution or winding up of the
Company and which is not subject to redemption by the Company. However,
subject to the provisions of Section 1211, shares issuable on conversion of
Securities shall include only shares of the class designated as Common Stock
of the Company at the date of this instrument or shares of any class or
classes resulting from any reclassification or reclassifications thereof and
which have no preference in

                                      3

<PAGE>

respect of dividends or of amounts payable in the event of any voluntary or
involuntary liquidation, dissolution or winding up of the Company and which
are not subject to redemption by the Company; PROVIDED that if at any time
there shall be more than one such resulting class, the shares of each such
class then so issuable shall be substantially in the proportion which the
total number of shares of such class resulting from all such
reclassifications bears to the total number of shares of all such classes
resulting from all such reclassifications.

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

          "Company Request" or "Company Order" means a written request or
order in the form of an Officers' Certificate.

          "Conversion Agent" means any Person authorized by the Company to
convert Securities in accordance with Article Twelve.

          "Conversion Price" has the meaning specified in Section 1201.

          "Converted Securities" means all Securities which have been
converted pursuant to Article Twelve.

          "Corporate Trust Office" means the principal office of the Trustee
in New York City, at which at any particular time its corporate trust
business shall be administered, which office at the date of original
execution of this Indenture is located at 4 Albany Street, New York, New York
10015.

          "corporation" includes corporations, associations, companies and
business trusts.

          "coupon" means any interest coupon appertaining to a Bearer
Security.

          "Defaulted Interest" has the meaning specified in Section 307.

          "Dollar" or "U.S. $" means a dollar or other equivalent unit in
such coin or currency of the United

                                      4

<PAGE>

States of America as at the time shall be legal tender for the payment of
public and private debts.

          "Event of Default" has the meaning specified in Section 501.

          "Exchange Date" means the date 90 days after completion of
distribution of the Securities as advised by SBCI to the Trustee in writing
pursuant to Section 304.

          "Global Security" means a temporary security in the form set forth
in Section 203.

          "Holder", when used with respect to any Security, means in the case
of a Registered Security the Person in whose name the Security is registered
in the Security Register and in the case of a Bearer Security or the Global
Security the bearer thereof and, when used with respect to any coupon, means
the bearer thereof.

          "Indenture" means this instrument as originally executed or as it
may from time to time be supplemented or amended by one or more indentures
supplemental hereto entered into pursuant to the applicable provisions hereof.

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

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

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

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

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

                                      5

<PAGE>

            (i) Securities theretofore cancelled by the Trustee or Principal
     Paying Agent or delivered to the Trustee or Principal Paying Agent for
     cancellation;

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

          (iii) Securities which have been paid pursuant to Section 306 or in
     exchange for or in lieu of which other Securities have been
     authenticated and delivered pursuant to this Indenture, other than any
     such Securities in respect of which there shall have been presented to
     the Trustee or Principal Paying Agent proof satisfactory to it that such
     Securities are held by a bona fide purchaser in whose hands such
     Securities are valid obligations of the Company;

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

          "Paying Agent" means any Person authorized by the Company to pay
the principal of and premium, if any, or

                                      6

<PAGE>

interest on any Securities on behalf of the Company (which term shall
include, except where the context otherwise requires, the Principal Paying
Agent).

          "Paying Agency Agreement" means the Paying Agency Agreement, dated
as of May 21, 1987, between the Company, the Principal Paying Agent and the
Paying Agents, Conversion Agents and Transfer Agents named therein.

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

          "Place of Conversion" has the meaning specified in Section 301.

          "Place of Payment" has the meaning specified in Section 301.

          "Predecessor Security" of any particular Security means every
previous Security evidencing all or a portion of the same debt as that
evidenced by such particular Security; and, for the purposes of this
definition, any Security authenticated and delivered under Section 306 in
exchange for or in lieu of a mutilated, destroyed, lost or stolen Security
shall be deemed to evidence the same debt as the mutilated, destroyed, lost
or stolen Security.

          "Principal Office" means the principal office of the Principal
Paying Agent in New York City at which at any particular time corporate trust
services are administered.

          "Principal Paying Agent" means any Person appointed by the Company
as Principal Paying Agent.

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

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

          "Registered Security" means any Security in the form for Registered
Securities set forth in Section 202 registered in the Security Register.

                                      7
<PAGE>

         "Regular Record Date" for the interest payable on any Interest
Payment Date means the May 7 (whether or not a Business Day) next preceding
each such Interest Payment Date.

         "Responsible Officer", when used with respect to the Trustee, means
any officer within the Corporate Trust and Agency Group (or any successor
group of the Trustee) including any vice president, assistant vice president,
assistant secretary or any other officer or assistant officer of the Trustee
customarily performing functions similar to those performed by the persons
who at the time shall be such officers, respectively, or to whom any
corporate trust matter is referred at the Corporate Trust Office because of
his knowledge of and familiarity with the particular subject.

         "Rights" has the meaning specified in Section 1204(3).

         "SBCI" means Swiss Bank Corporation International Limited.

         "Security Register" and "Security Registrar" have the respective
meanings specified in Section 305.

         "Senior Debt" means the present and future principal of and premium,
if any, and interest on (a) indebtedness of the Company for money borrowed
evidenced by bonds, notes, debentures or similar obligations, including any
guaranty by the Company of any indebtedness for money borrowed of any other
Person, whether outstanding on the date of the Indenture or thereafter
created, assumed or incurred; (b) indebtedness incurred, assumed or
guaranteed by the Company in connection with the acquisition by it or a
Subsidiary of any other businesses, properties or other assets (except
purchase-money indebtedness classified as accounts payable under generally
accepted accounting principles); (c) obligations of the Company as lessee
under leases required to be capitalized on the balance sheet of the lessee
under generally accepted accounting principles and leases of property or
assets made as part of any sale and lease-back transaction to which the
Company is a party; (d) reimbursement obligations in respect of letters of
credit relating to indebtedness or other obligations of the Company that
qualify as Senior Debt; and (e) any refundings, renewals or extensions of any
indebtedness described in clauses (a), (b), (c) and (d), unless in the
instrument creating or evidencing the indebtedness it is provided that


                                       8

<PAGE>

such indebtedness is not superior in right of payment to the Securities.

         "Special Record Date" for the payment of any Defaulted Interest
means a date fixed by the Trustee pursuant to Section 307.

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

         "Subsidiary" means any corporation or other entity at least a
majority of the outstanding voting shares of which is at the date of
determination directly owned or controlled by the Company or any Subsidiary,
or which corporation or entity is otherwise consolidated with the Company
for financial reporting purposes.

         "Transfer Agent" means any Person, which may be the Company,
authorized by the Company to exchange or register the transfer of Securities.

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

         "United States" means the United States of America (including the
States and the District of Columbia), its territories, its possessions and
other areas subject to its jurisdiction.

         "United States Alien" has the meaning set forth in the forms of
Definitive Securities contained in Section 202.

         "United States Bank Branch" means a branch located outside the
United States of a bank organized under federal or state law in the United
States.

         "United States Institutional Investor" means any Person who delivers
the letter in the form of Exhibit E to the Indenture in connection with its
acquisition of Securities and as to whom SBCI delivers the certificate in the
form of Exhibit D to the Indenture.


                                       9

<PAGE>

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

         SECTION 102.  FORM OF DOCUMENTS DELIVERED TO TRUSTEE.

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

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

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

         SECTION 103.  ACTS OF HOLDERS OF SECURITIES.

         (a) Any request, demand, authorization, direction, notice, consent,
election, waiver or other action provided by this Indenture to be given or
taken by Holders of Securities may be embodied in and evidenced by (1) one or
more instruments of substantially similar tenor


                                      10

<PAGE>

signed by such Holders in person or by agent or proxy duly appointed in
writing, (2) the record of Holders of Securities voting in favor thereof,
either in person or by proxies duly appointed in writing, at any meeting of
Holders of Securities duly called and held in accordance with the provisions
of Article Nine, or (3) a combination of such instruments and any such
record. Except as herein otherwise expressly provided, such action shall
become effective when such instrument or instruments or record or both are
delivered to the Trustee and, where it is hereby expressly required, to the
Company. Such instrument or instruments and record (and the action embodied
therein and evidenced thereby) are herein sometimes referred to as the "Act"
of the Holders of Securities signing such instrument or instruments or so
voting at such meeting. Proof of execution of any such instrument or of a
writing appointing any such agent or proxy, or of the holding by any Person
of a Security, shall be sufficient for any purpose of this Indenture and
(subject to Section 601) conclusive in favor of the Trustee and the Company
if made in the manner provided in this Section. The record of any meeting of
Holders of Securities shall be proved in the manner provided in Section 906.

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

         (c) The principal amount and serial numbers of Bearer Securities
held by any Person, and the date of his holding the same, may be proved by
the production of such Bearer Securities or by a certificate executed, as
depositary, by any trust company, bank, banker or other depositary, wherever
situated, if such certificate shall be deemed by the Trustee to be
satisfactory, showing that at the date therein mentioned such Person had on
deposit with such depositary, or exhibited to it, the Bearer Securities
therein described; or such facts may be proved by the


                                      11

<PAGE>

certificate or affidavit of the Person holding such Bearer Securities, if
such certificate or affidavit is deemed by the Trustee to be satisfactory.
The Trustee and the Company may assume that such ownership of any Bearer
Security continues until (1) another certificate or affidavit bearing a later
date issued in respect of the same Bearer Security is produced, or (2) such
Bearer Security is produced to the Trustee by some other Person, or (3) such
Bearer Security is surrendered in exchange for a Registered Security, or (4)
such Bearer Security is no longer Outstanding.

         (d) The fact and date of execution of any such instrument or
writing, the authority of the Person executing the same and the principal
amount and serial numbers of Bearer Securities held by the Person so
executing such instrument or writing and the date of holding the same may
also be proved in any other manner which the Trustee deems sufficient; and
the Trustee may in any instance require further proof with respect to any of
the matters referred to in this Section.

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

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

         SECTION 104.  NOTICES, ETC., TO TRUSTEE AND COMPANY.

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

         (1) the Trustee by any Holder of Securities or by the Company shall
    be sufficient for every purpose hereunder if made, given, furnished or
    filed in writing to or with the Trustee at its Corporate Trust Office, or


                                      12

<PAGE>

         (2) the Company by the Trustee or by any Holder of Securities shall
    be sufficient for every purpose hereunder (unless otherwise herein
    expressly provided) if in writing, mailed, first-class postage prepaid,
    or telexed or telecopied and confirmed by mail, first-class postage
    prepaid, addressed to it at the address of its principal office specified
    in the first paragraph of this instrument, to the attention of its
    Treasurer, or at any other address previously furnished in writing to the
    Trustee by the Company.

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

         SECTION 105.  NOTICE TO HOLDERS OF SECURITIES; WAIVER.

         Except as otherwise expressly provided herein, where this Indenture
provides for notice to Holders of Securities of any event (the expense for which
shall be borne by the Company),

         (1) such notice shall be sufficiently given to Holders of Bearer
    Securities if published in an Authorized Newspaper in London and, so long
    as the Securities are listed on the Luxembourg Stock Exchange and such
    Exchange so requires, in Luxembourg, on a Business Day not earlier than
    the earliest date and not later than the latest date prescribed for the
    giving of such notice. If publication in London or Luxembourg is not
    practicable, such publication shall be in an Authorized Newspaper
    elsewhere in Western Europe; and

         (2) such notice shall be sufficiently given to Holders of Registered
    Securities if in writing and mailed, first-class postage prepaid, to each
    Holder of a Registered Security, at the address of such Holder as it
    appears in the Security Register, not earlier than the earliest date, and
    not later than the latest date, prescribed for the giving of such notice.

         Neither failure to give notice by publication to Holders of Bearer
Securities as provided above, nor any defect in any notice so published,
shall affect the sufficiency of any notice mailed to Holders of Registered


                                      13

<PAGE>

Securities as provided above. In case by reason of the suspension of
publication of any Authorized Newspaper or Authorized Newspapers or by reason
of any other cause it shall be impracticable to publish any notice to Holders
of Bearer Securities as provided above, then such notification to Holders of
Bearer Securities as shall be given with the approval of the Trustee shall
constitute sufficient notice to such Holders for every purpose hereunder.

         In any case where notice to Holders of Registered Securities is
given by mail, neither the failure to mail such notice, nor any defect in any
notice so mailed, to any particular Holder of a Registered Security shall
affect the sufficiency of such notice with respect to other Holders of
Registered Securities or the sufficiency of any notice by publication to
Holders of Bearer Securities given as provided above. In case by reason of
the suspension of regular mail service or by reason of any other cause it
shall be impracticable to give such notice by mail, then such notification to
Holders of Registered Securities as shall be made with the approval of the
Trustee shall constitute a sufficient notification to such Holders for every
purpose hereunder.

         Where this Indenture provides for notice in any manner, such notice
may be waived in writing by the Person entitled to receive such notice,
either before or after the event, and such waiver shall be the equivalent of
such notice. Waivers of notice by Holders shall be filed with the Trustee,
but such filing shall not be a condition precedent to the validity of any
action taken in reliance upon such waiver.

         SECTION 106.  EFFECT OF HEADINGS AND TABLE OF CONTENTS.

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

         SECTION 107.  SUCCESSORS AND ASSIGNS.

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


                                      14
<PAGE>

         SECTION 108.  SEPARABILITY CLAUSE.

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

         SECTION 109.  BENEFITS OF INDENTURE.

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

         SECTION 110.  GOVERNING LAW; SUBMISSION TO JURISDICTION.

         This Indenture and each of the Securities and coupons shall be
governed by and construed in accordance with the laws of the State of New
York.

         The Company hereby submits to the non-exclusive jurisdiction of any
United States Federal or New York State court sitting in New York City solely
for the purpose of any legal action or proceeding brought to enforce the
Company's obligations hereunder or with respect to any Security. As long as
any of the Securities remain outstanding, the Company shall have an
authorized agent in New York City upon whom process may be served in any such
legal action or proceeding. Service of process upon such agent and written
notice of such service mailed or delivered to the Company shall to the extent
permitted by law be deemed in every respect effective service of process upon
the Company in any such legal action or proceeding. The Company hereby
appoints C.T. Corporation System, 1633 Broadway, New York, N.Y. 10019 as its
agent for such purposes, and covenants and agrees that service of process in
any legal action or proceeding may be made upon it at the corporate trust
office or at the principal office in New York City of such agent.

         SECTION 111.  LEGAL HOLIDAYS.

         In any case where any Interest Payment Date, any Redemption Date or
the Stated Maturity of any Security or the last day on which a Holder of a
Security has the right


                                      15

<PAGE>

to convert his Security shall not be a Business Day at any Place of Payment
or Place of Conversion or in London or New York, then (notwithstanding any
other provision of this Indenture or of the Securities or coupons) payment of
interest or principal and premium, if any, or conversion of the Securities
need not be made at such Place of Payment or Place of Conversion on such day,
but may be made on the next succeeding Business Day at such Place of Payment
or Place of Conversion with the same force and effect as if made on the
Interest Payment Date or Redemption Date, or at the Stated Maturity or on
such last day for conversion, PROVIDED that, in the case of payment, no
interest shall accrue on the amount so payable for the period from and after
such Interest Payment Date, Redemption Date or Stated Maturity, as the case
may be.


                                      16

<PAGE>

                                  ARTICLE TWO

                                 Security Forms

         SECTION 201.  FORMS GENERALLY.

         The Securities and the coupons shall be in substantially the forms
set forth in this Article, with such appropriate insertions, omissions,
substitutions and other variations as are required or permitted by this
Indenture, and may have such letters, numbers or other marks of
identification and such legends or endorsements placed thereon as may be
required to comply with the rules of any securities exchange or applicable
law or as may, consistently herewith, be determined necessary or appropriate
by the officers executing such Securities and coupons, as evidenced by their
execution of the Securities.

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

         Conversion notices shall be in substantially the form set forth in
this Article.

         The definitive Securities and coupons shall be printed, lithographed
or engraved or produced by any combination of these methods on steel engraved
borders or may be produced in any other manner, all as determined by the
officers executing such Securities and coupons, as evidenced by their
execution of such Securities, and in conformity with the requirements of the
Luxembourg Stock Exchange.

         SECTION 202.  FORMS OF DEFINITIVE SECURITIES.

                      [FORM OF FACE]

[IF BEARER SECURITY:

         ANY UNITED STATES PERSON WHO HOLDS THIS OBLIGATION WILL BE SUBJECT
TO LIMITATIONS UNDER THE UNITED STATES INCOME TAX LAWS, INCLUDING THE
LIMITATIONS PROVIDED IN SECTIONS 165(j) AND 1287(a) OF THE INTERNAL REVENUE
CODE.

                                      17

<PAGE>

                              CETUS CORPORATION

5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES DUE 2002

No. B-                                                           U.S. $5,000

         CETUS CORPORATION, a corporation duly organized and existing under
the laws of the State of Delaware (herein called the "Company", which term
includes any successor corporation under the Indenture referred to on the
reverse hereof), for value received, hereby promises to pay to bearer upon
presentation and surrender of this Security the principal sum of Five
Thousand United States Dollars on May 21, 2002 and to pay interest thereon,
from May 21, 1987 or from the most recent Interest Payment Date to which
interest has been paid or duly provided for, annually in arrears on May 21 in
each year (each of such dates being an "Interest Payment Date"), commencing
May 21, 1988, at the rate of 5 1/4 per cent. per annum, until the principal
hereof is paid or made available for payment. Such payments (including
premium, if any) shall be made, subject to any laws or regulations applicable
thereto and to the right of the Company (limited as provided in the
Indenture) to terminate the appointment of any such Paying Agent, only at the
main offices of Morgan Guaranty Trust Company of New York in Brussels and
London, Banque Internationale a Luxembourg S.A. in Luxembourg, Algemene Bank
Nederland N.V. in Amsterdam and Swiss Bank Corporation in Basel, or at such
other offices or agencies outside the United States (as defined below) as the
Company may designate and notify the Holder as provided on the reverse
hereof, by United States dollar check drawn on a bank in The City of New
York, or by transfer to a United States dollar account maintained by the
Holder with a bank outside the United States. Interest on this Security due
on or before maturity (but not any additional interest which may be payable
as provided below in respect of principal of, and premium, if any, on, this
Security) shall be payable only upon presentation and surrender at such
office or agency of the interest coupons hereto attached as they severally
mature. No payment of principal, premium or interest with respect to this
Security shall be made at the Corporate Trust Office of the Trustee under the
Indenture or at the Principal Office of the Principal Paying Agent or at any
other office or agency in the United States nor will any such payment be made
by mail to an address in the United States or by transfer to an account in
the United States. Notwithstanding the foregoing, payment of principal of and
premium, if any, and interest on this Security and payment


                                      18

<PAGE>

of any such additional interest may be made at the Principal Office of the
Principal Paying Agent in the Borough of Manhattan, The City of New York if
(but only if) payment of the full amount of such principal, premium, interest
or additional interest, as the case may be, at all offices outside the United
States maintained for the purpose by the Company in accordance with the
Indenture is illegal or effectively precluded because of the imposition of
exchange controls or other similar restrictions on the full payment or
receipt of such amounts in Dollars.]

[IF REGISTERED SECURITY:

         THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE UNITED STATES
SECURITIES ACT OF 1933 AND MAY NOT BE OFFERED OR SOLD EXCEPT IN COMPLIANCE
WITH SUCH ACT. THE TRANSFER OF THIS SECURITY IS SUBJECT TO CERTAIN
RESTRICTIONS AS SET FORTH IN A LETTER TO SWISS BANK CORPORATION INTERNATIONAL
LIMITED AND CETUS CORPORATION EXECUTED BY OR ON BEHALF OF THE HOLDER HEREOF.[*]

            THIS SECURITY CANNOT BE EXCHANGED FOR A BEARER SECURITY.




----------
*   This legend to appear only on Securities privately placed with United
    States Institutional Investors and, except as provided in Section 305 of
    the Indenture, on Securities issued upon transfer or exchange for such
    Securities.


                                      19

<PAGE>

                              CETUS CORPORATION

5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES DUE 2002

No. R-                                                          U.S. $_________

         CETUS CORPORATION, a corporation duly organized and existing under
the laws of the State of Delaware (herein called the "Company", which term
includes any successor corporation under the Indenture referred to on the
reverse hereof), for value received, hereby promises to pay to ______________
______________________________, or registered assigns, the principal sum of
______________________ Thousand United States Dollars on May 21, 2002 and to
pay interest thereon, from May 21, 1987 or the most recent Interest Payment
Date to which interest has been paid or duly provided for, annually in
arrears on May 21 in each year (each of such dates being an "Interest Payment
Date"), commencing May 21, 1988, at the rate of 5 1/4 per cent. per annum,
until the principal hereof is paid or made available for payment. The
interest so payable, and punctually paid or duly provided for, on any
Interest Payment Date will, as provided in the Indenture, be paid to the
Person in whose name this Security (or one or more Predecessor Securities) is
registered at the close of business on the Regular Record Date for such
interest, which shall be the May 7 (whether or not a Business Day) next
preceding each such Interest Payment Date. Except as otherwise provided in
the Indenture, any such interest not so punctually paid or duly provided for
will forthwith cease to be payable to the Holder on such Regular Record Date
and may either be paid to the Person in whose name this Security (or one or
more Predecessor Securities) is registered at the close of business on a
Special Record Date for the payment of such Defaulted Interest to be fixed by
the Trustee, notice whereof shall be given to Holders of Securities not less
than 10 days prior to such Special Record Date, or be paid at any time in any
other lawful manner not inconsistent with the requirements of any securities
exchange on which the Securities may be listed, and upon such notice as may
be required by such exchange, all as more fully provided in the Indenture.
Payments of principal of and premium, if any, on this Security shall be made
at the option of the Holder (a) at the office in the Borough of Manhattan,
The City of New York of the Principal Paying Agent, or at such other office
or agency of the Company as may be designated by it for such purpose in the
Borough of Manhattan, The City of New York, not less than three Business Days
prior to the due date for payment, in such coin or currency of


                                      20

<PAGE>

the United States of America as at the time of payment shall be legal tender
for the payment of public and private debts or (b) subject to any laws or
regulations applicable thereto and to the right of the Company (limited as
provided in the Indenture) to terminate the appointment of any such Paying
Agent, at the main offices of Banque Internationale a Luxembourg S.A. in
Luxembourg, or at such other offices or agencies which are both Paying and
Transfer Agents as the Company may designate and notify the Holder as
provided on the reverse hereof, by United States dollar check drawn on, or by
transfer to a United States dollar account maintained by the payee with, a
bank in The City of New York. Payment of interest on this Security shall be
made by United States dollar check drawn on a bank in The City of New York
and mailed to the address of the Person entitled thereto as such address
shall appear in the Security Register, or upon application by the Holder
hereof to the Security Registrar not later than the Regular Record Date in
the year the payment is to be received, by transfer to a United States dollar
account maintained by the payee with a bank in The City of New York.]

         The Company will, subject to the exceptions and limitations set
forth below, pay as additional interest to the Holder of a Security or coupon
that is a United States Alien (as defined below) such amounts as may be
necessary so that every net payment on such Security or coupon, after
withholding for or on account of any present or future tax, assessment or
other governmental charge imposed upon or as a result of such payment by the
United States (or any political subdivision or taxing authority thereof or
therein), will not be less than the amount provided in such Security or
coupon to be then due and payable. However, the Company will not be required
to make any payment of additional interest for or on account of:

         (a)  any tax, assessment or other governmental charge that would not
have been imposed but for (i) the existence of any present or former
connection between such Holder (or between a fiduciary, settlor or
beneficiary of, or a person holding a power over, such Holder, if such
Holder is an estate or a trust, or a member or shareholder of such Holder, if
such Holder is a partnership or corporation) and the United States,
including, without limitation, such Holder (or such fiduciary, settlor,
beneficiary, person holding a power, member or shareholder) being or having
been a citizen or resident thereof or being or having been engaged in trade
or business or present therein or having or having had a permanent
establishment therein,


                                      21

<PAGE>

or (ii) such Holder's past or present status as a personal holding company,
foreign personal holding company or private foundation or other tax-exempt
organization for purposes of United States federal income tax or as a
corporation that accumulates earnings to avoid United States federal income
tax;

         (b)  any estate, inheritance, gift, sales, transfer or personal
property tax or any similar tax, assessment or other governmental charge;

         (c)  any tax, assessment or other governmental charge that would not
have been imposed but for the presentation by the Holder of a Security or
coupon for payment more than 15 days after the date on which such payment
became due and payable or the date on which payment thereof was duly provided
for, whichever occurred later;

         (d)  any tax, assessment or other governmental charge that is
payable otherwise than by withholding from a payment on a Security or coupon;

         (e)  any tax, assessment or other governmental charge required to be
withheld by any Paying Agent from a payment on a Security or coupon, if such
payment can be made without such withholding by any other Paying Agent;

         (f)  any tax, assessment or other governmental charge that would not
have been imposed but for a failure to comply with applicable certification,
information, documentation or other reporting requirements concerning the
nationality, residence, identity or connection with the United States (or any
political subdivision thereof) of the Holder or beneficial owner of a
Security or coupon if, without regard to any tax treaty, such compliance is
required by statute or regulation of the United States (or any political
subdivision or taxing authority thereof or therein) as a precondition to
relief or exemption from such tax, assessment or other governmental charge; or

         (g)  any tax, assessment or other governmental charge imposed on a
Holder that actually or constructively owns 10 per cent. or more of the
combined voting power of all classes of voting stock of the Company or that
is a controlled foreign corporation related to the Company through stock
ownership;

nor shall additional interest be paid with respect to a payment on a Security
or coupon to a Holder that is a


                                      22


<PAGE>


fiduciary or partnership or other than the sole beneficial owner of such
payment to the extent such payment would be required by the laws of the United
States (or any political subdivision thereof) to be included in the income for
tax purposes of a beneficiary or settlor with respect to such fiduciary or a
member of such partnership or a beneficial owner that would not have been
entitled to the additional interest had such beneficiary, settlor, member or
beneficial owner been the Holder of such Security or coupon.

    The term "United States Alien" means any person who, for United States
federal income tax purposes, is a foreign corporation, a non-resident alien
individual, a non-resident alien fiduciary of a foreign estate or trust, or a
foreign partnership one or more of the members of which is, for United States
federal income tax purposes, a foreign corporation, a non-resident alien
individual or a non-resident alien fiduciary of a foreign estate or trust. The
term "United States" means the United States of America (including the States
and the District of Columbia), its territories, its possessions and other areas
subject to its jurisdiction.

    If and so long as the certification, documentation, information or other
reporting requirement referred to in the fourth paragraph on the reverse hereof
would be fully satisfied by payment of a backup withholding tax or similar
charge, the Company may elect to pay as additional interest such amounts as may
be necessary so that every net payment made outside the United States following
the effective date of such requirement by the Company or any of its Paying
Agents in respect of any Bearer Security or any coupon of which the beneficial
owner is a United States Alien (but without any requirement that the
nationality, residence or identity of such beneficial owner be disclosed to the
Company, any Paying Agent or any governmental authority), after deduction or
withholding for or on account of such backup withholding tax or similar charge
(other than a backup withholding tax or similar charge which (i) would not be
applicable in the circumstances referred to in the second parenthetical clause
of the first sentence of the fourth paragraph on the reverse hereof, or (ii) is
imposed as a result of presentation of such Bearer Security or coupon for
payment more than 15 days after the date on which such payment became due and
payable or on which payment thereof was duly provided for, whichever occurred
later), will not be less than the amount provided in such Bearer Security or
coupon to be then due and payable. If the Company elects to pay additional
interest

                                23
<PAGE>

pursuant to this paragraph, the Company shall have the right to redeem the
Securities at any time as a whole at a Redemption Price equal to the
principal amount thereof, together with accrued interest to the date fixed
for redemption, subject to the provisions of the last two sentences of the
fourth paragraph on the reverse hereof. If the Company elects to pay
additional interest pursuant to this paragraph and the condition specified in
the first sentence of this paragraph should no longer be satisfied, then the
Company shall redeem the Securities as a whole at a Redemption Price equal to
the principal amount thereof, together with accrued interest to the date
fixed for redemption, subject to the provisions of the last two sentences of
the fourth paragraph on the reverse hereof. Any redemption payments made by
the Company pursuant to the two immediately preceding sentences shall be
subject to the continuing obligation of the Company to pay additional
interest pursuant to this paragraph.

    Except as specifically provided herein and in the Indenture, the Company
shall not be required to make any payment with respect to any tax, assessment or
other governmental charge imposed upon or as a result of payments on the
Securities or coupons by any government or any political subdivision or taxing
authority thereof or therein.

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

[IF BEARER SECURITY:

    Unless the certificate of authentication hereon has been executed by the
Trustee by the manual signature of one of its authorized signatories, neither
this Security, nor any coupon appertaining hereto, shall be entitled to any
benefit under the Indenture or be valid or obligatory for any purpose.

    IN WITNESS WHEREOF, the Company has caused this Security to be duly executed
under its corporate seal and coupons bearing the facsimile signature of its
Chief Financial Officer or Treasurer to be annexed hereto.

Dated as of May 21, 1987]

[IF REGISTERED SECURITY:

                                 24
<PAGE>


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

    IN WITNESS WHEREOF, the Company has caused this Security to be duly
executed under its corporate seal.

Dated:__________________]


                                   CETUS CORPORATION


                                   By ___________________________




Attest:

__________________________
        Secretary



                             [Form of Reverse]


    This Security is one of a duly authorized issue of Securities of the
Company designated as its 5 1/4 per cent. Convertible Subordinated Debentures
due 2002 (herein called the "Securities"), limited (except as otherwise provided
in the Indenture) in aggregate principal amount to U.S. $100,000,000, issued and
to be issued under an Indenture, dated as of May 21, 1987 (herein called the
"Indenture"), between the Company and BANKERS TRUST COMPANY, as Trustee (herein
called the "Trustee", which term includes any successor trustee under the
Indenture), to which Indenture and all indentures supplemental thereto reference
is hereby made for a statement of the respective rights, limitations of rights,
duties and immunities thereunder of the Company, the Trustee, the holders of
Senior Debt and the Holders of the Securities and any coupons appertaining
thereto and of the terms upon which the Securities are, and are to be,
authenticated and delivered. The Securities are issuable as Bearer Securities,
with interest coupons attached, in the denomination of U.S. $5,000 each and as
Registered Securities, without coupons, in denominations of U.S. $5,000 and
integral multiples thereof. As provided in

                                25
<PAGE>

the Indenture and subject to certain limitations therein set forth, [IF
BEARER SECURITY - Bearer Securities and] Registered Securities are exchangeable
for a like aggregate principal amount of Registered Securities of any authorized
denominations as requested by the Holder surrendering the same upon surrender of
the Security or Securities to be exchanged, [IF BEARER SECURITY - with all
unmatured coupons and all matured coupons in default thereto appertaining,
except as provided below,] at the office or agency of the Company in the Borough
of Manhattan, The City of New York or, subject to any laws or regulations
applicable thereto and to the right of the Company to terminate the appointment
of any such Transfer Agent, at the main offices of Banque Internationale a
Luxembourg S.A. in Luxembourg, or at such other offices or agencies as the
Company may designate. [IF BEARER SECURITY - Bearer Securities surrendered in
exchange for Registered Securities between a Regular Record Date and the
relevant Interest Payment Date will not be required to be surrendered with the
coupon relating to such Interest Payment Date.] Registered Securities, including
Registered Securities received in exchange for Bearer Securities, may not be
surrendered in exchange for Bearer Securities.

    The Securities may be redeemed, at the option of the Company, as a whole or
in part at any time after the expiration of 90 days following the Exchange Date,
upon notice given in the manner provided below, at a Redemption Price (expressed
as a percentage of the principal amount of the Securities to be redeemed) set
forth below, if redeemed during the 12-month period beginning May 21 of the
years indicated;

<TABLE>
    <S>             <C>                <C>             <C>
    1987 .........  106 per cent.      1990 .........  103 per cent.
    1988 .........  105 per cent.      1991 .........  102 per cent.
    1989 .........  104 per cent.      1992 .........  101 per cent.
</TABLE>

and at their principal amount if redeemed thereafter, in each case together
with accrued interest to the Redemption Date; PROVIDED, HOWEVER, that interest
installments on Bearer Securities the Stated Maturity of which installment is on
or prior to such Redemption Date will be payable only upon presentation and
surrender of coupons for such interest (at an office or agency outside the
United States except as otherwise provided herein), and PROVIDED, FURTHER, that
interest installments on Registered Securities whose Stated Maturity is on or
prior to such Redemption Date will be payable to the Holders of such
Securities, or one or more Predecessor Securities, of record at the close of
business


                                  26
<PAGE>


on the relevant Regular Record Date referred to on the face hereof, all as
provided in the Indenture. Notwithstanding the foregoing, the Securities may not
be so redeemed prior to May 21, 1990, unless the Closing Market Price Per Share
(as defined in the Indenture) of the Common Stock has been at least 130 per
cent. of the Conversion Price for any 25 trading days out of the 35 consecutive
trading days (being days on which there was such a price) prior to the initial
publication of the notice of such redemption.

    The Securities may also be redeemed at the option of the Company as a whole
at any time, on not less than 30 nor more than 60 days' notice, at a Redemption
Price equal to the principal amount thereof, together with accrued interest to
the date fixed for redemption, if the Company determines that it has or will
become obligated to pay additional interest on the Securities pursuant to the
second paragraph on the face of the Securities on the next succeeding Interest
Payment Date as a result of any change in, or amendment to, the laws (or any
regulations or rulings promulgated thereunder) of the United States or any
political subdivision or taxing authority thereof or therein, or any change in
official position regarding the application or interpretation of such laws,
regulations or rulings, which change or amendment occurs on or after May 5,
1987. Before publication of any notice of redemption pursuant to this
paragraph, the Company shall deliver to the Trustee and the Principal Paying
Agent (i) a certificate stating that the Company is entitled to redeem and
setting forth a statement of facts showing that the conditions precedent to the
right of the Company to redeem have occurred, and (ii) an opinion of independent
counsel satisfactory to the Trustee to such effect based on such statement of
facts.

    If the Company shall determine that any payment made outside the United
States by the Company or any of its Paying Agents in respect of any Bearer
Security or coupon would, under any present or future laws or regulations of the
United States (or any political subdivision or taxing authority thereof or
therein), be subject to any certification, documentation, information or other
reporting requirement of any kind, the effect of which requirement is the
disclosure to the Company, any Paying Agent or any governmental authority of the
nationality, residence or identity of a beneficial owner of such Bearer Security
or coupon that is a United States Alien (other than a requirement (a) that
would not be applicable to a payment made by the Company or any one of its
Paying Agents (i) directly to the

                                      27
<PAGE>


beneficial owner or (ii) to a custodian, nominee or other agent of the
beneficial owner or (b) that can be satisfied if such custodian, nominee or
other agent certifies that the beneficial owner is a United States Alien,
provided that in any case referred to in clause (a)(ii) or (b), payment by
the custodian, nominee or agent to the beneficial owner is not otherwise
subject to any such requirement), the Company shall elect either (x) to
redeem the Securities, as a whole, at a Redemption Price equal to the
principal amount thereof, together with accrued interest to the date fixed
for redemption, or (y) if the conditions of the fourth paragraph on the face
hereof are satisfied, to pay the additional interest specified in such
paragraph. The Company shall make such determination as soon as practicable
and publish prompt notice thereof (the "Determination Notice"), stating the
effective date of such certification, documentation, information or reporting
requirement, whether the Company elects to redeem the Securities or to pay
the additional interest specified in the fourth paragraph on the face hereof,
and (if applicable) the last date by which the redemption of the Securities
must take place, as provided in the next succeeding sentence. If the
Securities are to be redeemed pursuant to this paragraph, the redemption
shall take place on such date, not later than one year after the publication
of the Determination Notice, as the Company shall specify by notice to the
Trustee and the Principal Paying Agent given at least 60 days before the date
fixed for redemption. Notice of such redemption shall be given to the Holders
of the Securities not more than 60 nor less than 30 days prior to the date
fixed for redemption. Notwithstanding the foregoing, the Company shall not
redeem the Securities if the Company shall subsequently determine, not less
than 30 days prior to the date fixed for redemption, that subsequent payments
on the Bearer Securities and coupons would not be subject to any such
certification, documentation, information or other reporting requirement, in
which case the Company shall publish prompt notice of such subsequent
determination and any earlier redemption notice shall be revoked and of
no further effect.

    Notice of intention to redeem Securities will be given by the Company to
the Holders of the Securities by publication in Authorized Newspapers in London
and, so long as the Securities are listed on the Luxembourg Stock Exchange and
such Exchange so requires, in Luxembourg or, if not practicable in London or
Luxembourg, elsewhere in Western Europe, and by mail to Holders of Registered
Securities. In the case of a redemption in whole, notice will be given once not
more than 60 nor less than 30 days

                                   28
<PAGE>

prior to the date fixed for redemption. In the case of a partial redemption,
notice will be given twice, the first such notice to be given not more than
75 nor less than 60 days prior to the date fixed for redemption, and the
second such notice at least 20 days thereafter but not less than 30 days
prior to the date fixed for redemption.

    In the event of a redemption in part, the Company shall not be required (i)
to register the transfer of or exchange Registered Securities or to exchange
Bearer Securities for Registered Securities for a period of 15 days immediately
preceding the date notice is given identifying the serial numbers of the
Securities called for such redemption; (ii) to register the transfer of or
exchange any Registered Security, or portion thereof, called for redemption; or
(iii) to exchange any Bearer Security called for redemption, PROVIDED, HOWEVER,
that a Bearer Security called for redemption may be exchanged for a Registered
Security which is simultaneously surrendered to the Security Registrar or
Transfer Agent making such exchange with written instruction for payment
consistent with the provisions of the Indenture.

    Subject to and upon compliance with the provisions of the Indenture, the
Holder of this Security is entitled, at his option, at any time on or after the
opening of business on the Exchange Date and on or before the close of business
on May 21, 2002, or in case this Security [IF REGISTERED SECURITY - or a portion
hereof] is called for redemption, then in respect of this Security [IF
REGISTERED SECURITY - or such portion hereof] until and including, but (unless
the Company defaults in making the payment due upon redemption) not after, the
close of business on the date five business days preceding the Redemption Date,
to convert this security [IF REGISTERED SECURITY - (or any portion of the
principal amount hereof which is U.S. $5,000 or an integral multiple thereof)],
at the principal amount hereof [IF REGISTERED SECURITY - or of such portion],
into fully paid and nonassessable shares (calculated as to each conversion to
the nearest 1/100 of a share) of Common Stock of the Company at a Conversion
Price equal to U.S. $37.00 per share of Common Stock (or at the current adjusted
Conversion Price if an adjustment has been made as provided in the Indenture) by
surrender of this Security together with [IF BEARER SECURITY - all unmatured
coupons and any matured coupons in default appertaining hereto] [IF
REGISTERED SECURITY - (if so required by the Company or the Security Registrar)
instruments of transfer in form satisfactory to the Company and the Security
Registrar,

                                     29
<PAGE>

duly executed by the registered Holder or by his duly authorized attorney
and, in case such surrender shall be made during the period from the
close of business on any Regular Record Date next preceding any Interest
Payment Date to the opening of business on such Interest Payment Date (unless
this Security or the portion thereof being converted has been called for
redemption on a Redemption Date within such period), also accompanied by
payment in funds reasonably acceptable to the Company of an amount equal to
the interest payable on such Interest Payment Date on the principal amount of
the Security then being converted (or, if such Registered Security was issued
in exchange for a Bearer Security after the close of business on such Regular
Record Date, by surrender of one or more coupons relating to such Interest
Payment Date or by both payment in such funds and surrender of such coupon or
coupons, in either case, in an amount equal to the interest payable on such
Interest Payment Date on the principal amount of the Security then being
converted),] and the conversion notice hereon duly executed [IF REGISTERED
SECURITY - (a) at the Principal Office in the Borough of Manhattan, the City
of New York of the Principal Paying Agent, or at such other office or agency
of the Company as may be designated by it for such purpose in the Borough of
Manhattan, The City of New York, or (b)] subject to any laws or regulations
applicable thereto and subject to the right of the Company to terminate the
appointment of any such Conversion Agent, [IF BEARER SECURITY - only] at the
main offices of Morgan Guaranty Trust Company of New York in Brussels or
Banque Internationale a Luxembourg S.A. in Luxembourg, or at such other
offices or agencies [IF BEARER SECURITY - outside the United States] as the
Company may designate. [IF BEARER SECURITY - Notwithstanding the foregoing,
this Security may be surrendered for conversion at the Principal Office in
the Borough of Manhattan, The City of New York of the Principal Paying Agent
if conversion at all Conversion Agents outside the United States is illegal
or is effectively precluded because of the imposition of exchange controls
or other similar restrictions.] [IF REGISTERED SECURITY - Subject to the
aforesaid requirement for payment and, in the case of a conversion after the
Regular Record Date next preceding any Interest Payment Date and on or before
such Interest Payment Date, to the right of the Holder of this Security (or
any Predecessor Security) of record at such Regular Record Date to receive an
installment of interest (with certain exceptions provided in the Indenture),
and subject] [IF BEARER SECURITY - Subject] to the provisions of the first
sentence of the second paragraph on the reverse of this Security, no payment
or adjustment is to be

                                       30
<PAGE>

made on conversion for interest accrued hereon or for dividends on the Common
Stock delivered on conversion. No fractions of shares or scrip representing
fractions of shares will be issued or delivered on conversion, but instead of
any fractional interest the Company shall pay a cash adjustment as provided
in the Indenture.

    The Conversion Price is subject to adjustment as provided in the
Indenture in certain events, including the payment of dividends or the making
of a distribution on the capital stock of the Company in shares of Common
Stock; subdivisions, combinations and reclassifications of the Common Stock; the
making of a distribution on the Common Stock in shares of capital stock other
than Common Stock; certain consolidations, mergers and sales of the property
of the Company; the issuance to all holders of Common Stock of certain rights
or warrants entitling them to subscribe for Common Stock at a price per share
below the then-current market price; and the distribution to all holders of
Common Stock of assets (other than cash) or certain rights or warrants to
purchase securities of the Company. No adjustment in the Conversion Price
will be required unless such adjustment would require a change of at least
one per cent. in the Conversion Price then in effect; provided, however, that
any adjustment that would otherwise be required to be made will be carried
forward and taken into account in determining any subsequent adjustment. The
Conversion Price will not be adjusted in the case of transactions in which
the Holders of Securities are entitled to participate or which effectuate a
change in the par value or lack thereof of the Common Stock. In addition, in
the case of certain of such rights and warrants, the Company may elect not to
adjust the Conversion Price but instead to provide that Holders of Securities
would receive the rights or warrants, if and when they convert their
Securities into Common Stock, to the extent such rights or warrants would
be issued with other shares of Common Stock issued at the time of conversion.
The Company is entitled from time to time to reduce the Conversion Price by
any amount for a minimum period of 20 days, by at least 15 days prior notice
to the Holders of Securities. The Company may also reduce the Conversion
Price in order to avoid taxation of its stockholders as a result of an
adjustment of, or failure to adjust, the Conversion Price.

    In addition, the Indenture provides that in case of certain consolidations
or mergers to which the Company is a party, the transfer of substantially all
of the assets of the Company as an entirety, or certain reclassifications

                                       31
<PAGE>

or changes of the shares of Common Stock, the Indenture shall be amended,
without the consent of any Holders of Securities, so that this Security, if
then outstanding, will be convertible thereafter, during the period this
Security shall be convertible as specified above, in lieu of conversion into
the shares of Common Stock deliverable on conversion immediately prior to such
event, only into the kind and amount of securities and/or cash and/or other
property receivable upon such consolidation, merger, transfer,
reclassification or change by a holder of the number of shares of Common
Stock into which such Security might have been converted immediately prior to
such consolidation, merger, transfer, reclassification or change, assuming,
if such consolidation, merger, transfer, reclassification or change is prior
to the Exchange Date, that this Security were convertible at the time of such
event at the initial Conversion Price specified above as adjusted from May 5,
1987 to such time pursuant to the Indenture.

    [IF REGISTERED SECURITY - In the event of redemption or conversion of this
Security in part only, a new Security or Securities for the unredeemed or
unconverted portion hereof will be issued in the name of the Holder hereof upon
the cancellation hereof.]

    The payment of the principal of, premium (if any) and interest on this
Security is subordinated in right of payment, to the extent set forth in the
Indenture, to the prior payment in full of all Senior Debt. Each Holder of this
Security [IF BEARER SECURITY - or any coupon appertaining to this Security], by
accepting the same, (a) agrees to and shall be bound by such provisions of the
Indenture, (b) authorizes and directs the Trustee on his behalf to take such
action as may be necessary or appropriate to effectuate the subordination of
this Security [IF BEARER SECURITY - and any such coupon] as provided in the
Indenture and (c) appoints the Trustee his attorney-in-fact for any and all such
purposes.

    If an Event of Default shall occur and be continuing, the principal of all
the Securities may be declared due and payable in the manner and with the effect
provided in the Indenture.

    The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities and coupons under

                                      32
<PAGE>

the Indenture at any time by the Company and the Trustee with the consent of
the Holders of a majority in aggregate principal amount of the Securities at
the time Outstanding (or such lesser amount as shall have acted at a meeting
pursuant to the provisions of the Indenture). The Indenture also contains
provisions permitting the Holders of specified percentages in aggregate
principal amount of the Securities at the time Outstanding, on behalf of the
Holders of all the Securities and coupons, to waive compliance by the Company
with certain provisions of the Indenture and certain past defaults under the
Indenture and their consequences. Any such consent or waiver by the Holder of
this Security shall be conclusive and binding upon such Holder and upon all
future Holders of this Security [IF BEARER SECURITY - and any coupon
appertaining hereto] and of any Security issued [IF REGISTERED SECURITY - upon
registration of transfer hereof or] in exchange herefor or in lieu hereof,
whether or not notation of such consent or waiver is made upon this Security
or such other Security.

    Subject to Article Thirteen of the Indenture, no reference herein to the
Indenture and no provision of this Security or of the Indenture shall alter or
impair the obligation of the Company, which is absolute and unconditional, to
pay the principal of (and premium, if any) and interest (including additional
interest, as described on the face hereof) on this Security at the times, places
and rate, and in the coin or currency, herein prescribed or to convert this
Security as provided in the Indenture.

    Title to Bearer Securities and coupons shall pass by delivery. As provided
in the Indenture and subject to certain limitations therein set forth, the
transfer of Registered Securities is registrable on the Security Register upon
surrender of a Registered Security for registration of transfer at the office of
Morgan Guaranty Trust Company of New York, as Security Registrar, in the Borough
of Manhattan, The City of New York or, subject to any laws or regulations
applicable thereto and to the right of the Company to terminate the appointment
of any such Transfer Agent, at the main offices of Banque Internationale a
Luxembourg S.A. in Luxembourg, or at such other offices or agencies as the
Company may designate, duly endorsed by, or accompanied by a written instrument
of transfer in form satisfactory to the Company and the Security Registrar or
any such Transfer Agent, as the case may be, duly executed by, the Holder
thereof or his attorney duly authorized in writing, and thereupon one or more
new Registered Securities, of authorized denominations and for the same

                                     33
<PAGE>

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

    The Company, the Trustee and any agent of the Company or the Trustee may
treat the bearer of a Bearer Security and any coupon appertaining thereto and,
prior to due presentment for registration of transfer, the Person in whose name
a Registered Security is registered as the owner thereof for all purposes,
whether or not the Security or coupon be overdue, and neither the Company, the
Trustee or any such agent shall be affected by notice to the contrary.

    The Indenture, the Securities and any coupons appertaining thereto shall be
governed by and construed in accordance with the law of the State of New York.

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

    SECTION 203. FORM OF TEMPORARY GLOBAL SECURITY.

    THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES
ACT OF 1933. NEITHER THIS SECURITY NOR ANY PORTION HEREOF MAY BE OFFERED OR
SOLD DIRECTLY OR INDIRECTLY IN THE UNITED STATES OF AMERICA (INCLUDING THE
STATES AND THE DISTRICT OF COLUMBIA), ITS TERRITORIES, ITS POSSESSIONS AND
OTHER AREAS SUBJECT TO ITS JURISDICTION ("UNITED STATES") OR TO ANY CITIZEN
OR RESIDENT OF THE UNITED STATES, ANY CORPORATION, PARTNERSHIP OR OTHER
ENTITY CREATED OR ORGANIZED IN OR UNDER THE LAWS OF THE UNITED STATES OR ANY
STATE THEREOF OR TO ANY ESTATE OR TRUST THE INCOME OF WHICH IS SUBJECT TO
UNITED STATES FEDERAL INCOME TAXATION REGARDLESS OF ITS SOURCE (ALL OF THE
FOREGOING BEING "U.S. PERSONS"), EXCEPT IN COMPLIANCE WITH THE REGISTRATION
REQUIREMENTS OF SUCH ACT OR AN EXEMPTION THEREFROM.

ANY UNITED STATES PERSON WHO HOLDS THIS OBLIGATION WILL BE SUBJECT TO
LIMITATIONS UNDER THE UNITED STATES INCOME TAX LAWS, INCLUDING THE LIMITATIONS
PROVIDED IN SECTIONS 165(j) AND 1287(a) OF THE INTERNAL REVENUE CODE.

                                   34
<PAGE>

                            CETUS CORPORATION

    5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES DUE 2002

                        TEMPORARY GLOBAL SECURITY

    CETUS CORPORATION, a corporation duly organized and existing under the laws
of the State of Delaware (herein called the "Company", which term includes any
successor corporation under the Indenture hereinafter referred to), for value
received, hereby promises to pay to bearer upon presentation and surrender of
this Global Security the principal sum of U.S. $100,000,000 on May 21, 2002 and
to pay interest thereon, from the date hereof, annually in arrears on May 21 in
each year, commencing May 21, 1988, at the rate of 5 1/4 per cent. per annum,
until the principal hereof is paid or made available for payment; PROVIDED,
HOWEVER, that interest on this Global Security shall be payable only after the
issuance of the definitive Securities for which this Global Security is
exchangeable and, in the case of definitive Securities in bearer form, only upon
presentation and surrender (at an office or agency outside the United States,
except as otherwise provided in the Indenture referred to below) of the interest
coupons thereto attached as they severally mature.

    This Global Security is issued in respect of an issue of Securities of the
Company designated as specified in the title hereof, issued and to be issued
under the Indenture, dated as of May 21, 1987 (herein called the "Indenture"),
between the Company and Bankers Trust Company, as Trustee (herein called the
"Trustee", which term includes any successor trustee under the Indenture). This
Global Security is a temporary security and is exchangeable in whole or from
time to time in part without charge upon request of the Holder hereof for
definitive Securities in bearer form, with interest coupons attached, or in
registered form, without coupons, of authorized denominations, (a) not earlier
than 90 days after the date on which the distribution of the Securities has been
completed as Swiss Bank Corporation International Limited shall have advised the
Trustee in writing and (b) as promptly as practicable following presentation of
certification, in the form set forth in Exhibit A to the Indenture, that the
beneficial owner or owners of this Global Security (or, if such exchange is only
for a part of this Global Security, of such part) (i) are not U.S. Persons or
(ii) are United States Bank Branches that have acquired the Securities in
compliance with the applicable requirements of Section 304

                                      35
<PAGE>

of the Indenture. Notwithstanding the foregoing, this Global Security is
exchangeable at any time for Registered Securities that have been sold to United
States Institutional Investors upon compliance with the applicable requirements
of Section 304 of the Indenture. Definitive Securities in bearer form to be
delivered in exchange for any part of this Global Security shall be delivered
only outside the United States. Upon any exchange of a part of this Global
Security for definitive Securities, the portion of the principal amount hereof
so exchanged shall be endorsed by the Trustee on the Schedule hereto, and the
principal amount hereof shall be reduced for all purposes by the amount so
exchanged.

    Until exchanged in full for definitive Securities, this Global Security
shall in all respects be entitled to the same benefits under, and subject to the
same terms and conditions of, the Indenture as definitive Securities
authenticated and delivered thereunder, except that neither the Holder hereof
nor the beneficial owners of this Global Security shall be entitled to receive
payment of interest hereon or to convert this Global Security into Common Stock
of the Company or any other security, cash or other property.

    This Global Security shall be governed by and construed in accordance with
the law of the State of New York.

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

    Unless the certificate of authentication hereon has been executed by the
Trustee by the manual or facsimile signature of one of its authorized officers,
this Global Security shall not be entitled to any benefit under the Indenture or
be valid or obligatory for any purpose.

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

Dated as of May 21, 1987

                                       CETUS CORPORATION

                                       By_______________________________
                                                  [Title]


                                     36

<PAGE>
                               SCHEDULE OF EXCHANGES


<TABLE>
<CAPTION>
                                          Remaining
                                          principal
                     Principal             amount
                      amount              following
   Date           exchanged for              such
   Made       definitive Securities       exchange          Notation made
   ----       ---------------------       ----------        -------------
   <S>        <C>                         <C>               <C>


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

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

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

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

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

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

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

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

   ----       ---------------------       ----------        -------------
</TABLE>


                         SECTION 204. FORM OF COUPON.

                               [Form of Face]

    ANY UNITED STATES PERSON WHO HOLDS THIS OBLIGATION WILL BE SUBJECT TO
LIMITATIONS UNDER THE UNITED STATES INCOME TAX LAWS, INCLUDING THE LIMITATIONS
PROVIDED IN SECTIONS 165(j) AND 1287(a) OF THE INTERNAL REVENUE CODE.

                                            No.
    CETUS CORPORATION                       U.S. $
                                            Due________

5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES DUE 2002

    Unless the Security to which this coupon appertains shall have been called
for previous redemption and payment thereof duly provided for or converted, on
the date set forth hereon, CETUS CORPORATION (herein called the

                                       37
<PAGE>

"Company") will pay to bearer, upon surrender hereof, the amount shown
hereon (together with any additional interest in respect thereof which the
Company may be required to pay according to the terms of said Security and the
Indenture referred to therein) only at the Paying Agents set out on the reverse
hereof or at such other places (which, except as otherwise provided in the
Security to which this coupon appertains, shall be located outside the United
States of America (including the States and the District of Columbia), its
territories, its possessions and other areas subject to its jurisdiction
("United States")) as the Company may determine from time to time, by United
States dollar check drawn on a bank in The City of New York, or by transfer to a
United States dollar account maintained by the payee with a bank located outside
the United States. No payment hereon will be made by mail to an address in the
United States or by transfer to an account in the United States.

                                CETUS CORPORATION

                                By____________________________
                                         [Title]



                                           38
<PAGE>


     SECTION 205.  FORM OF TRUSTEE'S CERTIFICATE OF AUTHENTICATION.

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

                                    ____________________________
                                    as TRUSTEE



                                    By_____________________________
                                         AUTHORIZED SIGNATORY


     SECTION 206. FORM OF CONVERSION NOTICE.

                              CONVERSION NOTICE

     The undersigned Holder of this Security hereby irrevocably
exercises the option to convert this Security [if Registered Security -- or
portion hereof (which is U.S. $5,000 or an integral multiple thereof) below
designated,] into shares of Common Stock in accordance with the terms of the
Indenture referred to in this Security [if Registered Security -- delivers
herewith the amount of interest payable on the next Interest Payment Date if
this conversion is made between the Regular Record Date for such Interest
Payment Date and such Interest Payment Date,] [if Bearer Security -- delivers
herewith the coupons appertaining to such Security,] and directs that such
shares, together with a check in payment for any fractional share [if Registered
Security -- and any Securities representing any unconverted principal amount
hereof,] be delivered to and be registered in the name of the undersigned unless
a different name has been indicated below. If shares [if Registered Security --
or Securities] are to be registered in the name of a Person other than the
undersigned, the undersigned will pay all transfer taxes payable with respect
thereto.

    Dated:____________________

                                             _____________________________
                                                      SIGNATURE

                                        40
<PAGE>

     If Bearer Security, please            [If Registered Security --
     print name and address of             IF ONLY A PORTION OF THE
     Holder:                               SECURITIES IS TO BE CONVERTED,
                                           PLEASE INDICATE:


                                            1.   PRINCIPAL AMOUNT TO BE
     _________________________                   CONVERTED (IN AN INTEGRAL
                                                 MULTIPLE OF U.S. $5,000
     _________________________                   IF LESS THAN ALL):
                                                 U.S. $
     _________________________

                                            2.   AMOUNT AND DENOMINATION
     IF SHARES OR SECURITIES                     OF SECURITIES REPRESENTING
     ARE TO BE REGISTERED IN THE                 UNCONVERTED PRINCIPAL AMOUNT
     NAME OF A PERSON OTHER THAN                 TO BE ISSUED:
     THE HOLDER, PLEASE PRINT
     SUCH PERSON'S NAME AND ADDRESS:             AMOUNT:   U.S. $

     _________________________                   DENOMINATIONS:

     _________________________                   U.S. $
                                                 (U.S. 5,000 OR AN INTEGRAL
     _________________________                   MULTIPLE THEREOF)]


                                       41

<PAGE>

                                ARTICLE THREE

                                The Securities

     SECTION 301. TITLE AND TERMS.

     The aggregate principal amount of Securities which may be authenticated
and delivered under this Indenture is limited to $100,000,000 except for
Securities authenticated and delivered upon registration of transfer of, or
in exchange for, or in lieu of, other Securities pursuant to Section 304,
305, 306, 805, 1109 or 1202.

     The Securities shall be known and designated as the "5 1/4 per cent.
Convertible Subordinated Debentures due 2002" of the Company. Their Stated
Maturity shall be May 21, 2002, and they shall bear interest at the rate of
5 1/4 per cent. per annum from May 21, 1987 payable annually in arrears on May
21 in each year, commencing May 21, 1988, until the principal thereof is paid
or made available for payment.

     The principal of (and premium, if any) and interest on the Securities
shall be payable as provided in the forms of Securities set forth in Section
202 (any city in which any Paying Agent is located being herein called a
"Place of Payment").

     The Securities shall be redeemable as provided in Article Eleven.

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

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

     SECTION 302. DENOMINATIONS.

     The definitive Securities shall be issuable in bearer form, with interest
coupons attached, in the denomination of U.S. $5,000 each and in fully
registered form, without coupons, in the denominations of U.S. $5,000 and
integral multiples thereof.

                                       42
<PAGE>

     SECTION 303. EXECUTION, AUTHENTICATION, DELIVERY AND DATING.

     The definitive Securities shall be executed on behalf of the Company by
its Chairman of the Board, its President or one of its Vice Presidents, under
its corporate seal reproduced thereon attested by its Secretary or one of its
Assistant Secretaries. The signature of any of these officers on the
definitive Securities may be manual or facsimile. Coupons shall bear the
facsimile signature of the Chief Financial Officer, the Treasurer or any
Assistant Treasurer of the Company. The temporary Global Security referred to
in Section 304 shall be manually executed on behalf of the Company by its
Chairman of the Board, its President or one of its Vice Presidents or by a
duly appointed attorney-in-fact of the Company, and need not bear the
corporate seal of the Company or any attestation by its Secretary or an
Assistant Secretary.

     Securities and coupons bearing the manual or facsimile signature of any
Person who was at any time a proper officer of the Company shall bind the
Company, notwithstanding that such Person has ceased to hold such office
prior to the authentication and delivery of such Securities or did not hold
such office at the date of such Securities.

     At any time and from time to time after the execution and delivery of
this Indenture, the Company may deliver Securities executed by the Company to
the Trustee for authentication, together with a Company Order for the
authentication and delivery of such Securities; and the Trustee in accordance
with the Company Order shall authenticate and deliver such Securities as in
this Indenture provided and not otherwise.

     Each Bearer Security and the Global Security shall be dated as of the
date of this Indenture. Each Registered Security shall be dated the date of
its authentication.

     No Security or coupon shall be entitled to any benefit under this
Indenture or be valid or obligatory for any purpose unless there appears on
such Security a certificate of authentication substantially in the form
provided for herein executed by the Trustee by manual signature, and such
certificate upon any Security shall be conclusive evidence, and the only
evidence, that such Security has been duly authenticated and delivered
hereunder. Except as permitted by Section 304, 306 or 307, the Trustee shall
not

                                     43
<PAGE>

authenticate and deliver any Bearer Security unless all appurtenant coupons
for interest then matured have been detached and cancelled.

     SECTION 304.   TEMPORARY GLOBAL SECURITY; EXCHANGE OF TEMPORARY GLOBAL
                    SECURITY FOR DEFINITIVE SECURITIES.

     The Securities shall be issued initially in the form of one temporary
Global Security, which temporary Global Security shall be deposited on behalf
of the purchasers of the Securities with a common depositary outside the
United States (the "Common Depositary"), for credit to their respective
accounts (or to such other accounts as they may direct) at Morgan Guaranty
Trust Company of New York, Brussels Office, as operator of the Euro-clear
System ("Euro-clear"), or CEDEL S.A. ("CEDEL").

     Without unnecessary delay but in any event prior to the Exchange Date,
the Company shall deliver to the Trustee definitive Securities in aggregate
principal amount equal to the principal amount of the Global Security,
executed by the Company. Such definitive Securities shall be in the form of
Bearer Securities or Registered Securities, or any combination thereof, as
may be specified by the Trustee. On and after the Exchange Date, except as
provided below, the interest of a beneficial owner of Securities in the
Global Security shall be exchanged for definitive Securities when the account
holder of Euro-clear or CEDEL that holds such interest on behalf of such
beneficial owner instructs Euro-clear or CEDEL, as the case may be, to
request such exchange on his behalf and delivers to Euro-clear or CEDEL, as
the case may be, a certificate substantially in the form set forth in Exhibit
B to this Indenture, copies of which certificate shall be available from the
offices of Euro-clear and CEDEL, the Trustee and each other paying agency of
the Company. If the beneficial owner of any Securities is a United States
Bank Branch, then that beneficial owner must deliver to the applicable
account holder a certificate substantially in the form of Exhibit C to this
Indenture prior to the submission by the account holder of a certificate
substantially in the form of Exhibit B to this Indenture in respect of those
Securities. Notwithstanding the foregoing, the interest of a United States
Institutional Investor in the Global Security shall be exchanged for
definitive Securities when SBCI instructs Euro-clear or CEDEL, as the case
may be, to request such exchange on its behalf and delivers to Euro-clear or
CEDEL, as the case may be, a certificate

                                   44
<PAGE>

substantially in the form set forth in Exhibit D to this Indenture.
Securities issued to United States Institutional Investors shall be
Registered Securities, shall bear the legend appearing on the face of the
form of definitive Registered Securities set forth in Section 202 and may be
in temporary form if the Company so elects and such exchange takes place
prior to the Exchange Date. Any exchange pursuant to this Section shall be
made free of charge to the beneficial owners of the Global Security, except
that a person receiving definitive Securities must bear the cost of
insurance, postage, transportation and the like in the event that such person
does not take delivery of such definitive Securities in person at the offices
of Euro-clear or CEDEL.

     Until so exchanged in full, the Global Security shall be surrendered by
the Common Depositary to the Trustee, as the Company's agent, for purposes of
the exchange of Securities described below. Following such surrender, upon
the request of Euro-clear or CEDEL, acting on behalf of beneficial owners of
Securities, the Trustee shall authenticate and deliver (outside the United
States, in the case of Bearer Securities) to Euro-clear or CEDEL, as the case
may be, for the account of such owners, definitive Securities in the form of
Bearer Securities or Registered Securities, or any combination thereof, as
shall be specified by such owners, in exchange for the aggregate principal
amount of the Global Security beneficially owned by such owners, but only
upon delivery by Euro-clear or CEDEL, acting on behalf of such owners, to the
Trustee at its principal office in London of a certificate or certificates
substantially in the form set forth in Exhibit A hereto. The delivery to the
Trustee by Euro-clear or CEDEL of such a certificate may be relied upon by
the Company and the Trustee as conclusive evidence that a related certificate
or certificates has or have been delivered to Euro-clear or CEDEL, as the
case may be, as contemplated by the terms of the next preceding paragraph.

     Upon any such exchange of a portion of the Global Security for definitive
Securities, the Global Security shall be endorsed to reflect the reduction of
the principal amount evidenced thereby. Until so exchanged in full, the
Global Security shall in all respects be entitled to the same benefits under,
and subject to the same terms and conditions of, this Indenture as definitive
Securities authenticated and delivered hereunder, except that none of
Euro-clear, CEDEL or the beneficial owners of the Global Security shall be
entitled to receive payment of interest

                                       45
<PAGE>

thereon or to convert the Global Security into Common Stock of the Company or
any other security, cash or other property.

     SECTION 305. REGISTRATION, REGISTRATION OF TRANSFER AND EXCHANGE.

     The Company shall cause to be kept at the Principal Office of the
Principal Paying Agent a register (the register maintained in such office and
in any other office or agency designated pursuant to Section 1002 as a
Transfer Agent being herein sometimes collectively referred to as the
"Security Register") in which, subject to such reasonable regulations as it
may prescribe, the Company shall provide for the registration of Registered
Securities and of transfers of Registered Securities. Pursuant to the Paying
Agency Agreement, the Company has appointed the Principal Paying Agent and
each Transfer Agent as "Security Registrars" for the purpose of registering
Registered Securities and transfers of Registered Securities as herein
provided.

     Subject to the provisions of this Section 305, upon surrender for
registration of transfer of any Registered Security at an office or agency of
the Company designated pursuant to Section 1002 for such purpose, the Company
shall execute, and the Trustee shall authenticate and deliver, in the name of
the designated transferee or transferees, one or more new Registered
Securities of any authorized denominations and of a like aggregate principal
amount.

     Registration of transfer of Registered Securities containing the first
legend set forth on the form of definitive Registered Security in Section 202
shall be effected only if:

          (i)  (A) the sale is to an Eligible Purchaser (as defined in
     Exhibit E to this Indenture) of at least U.S. $500,000 principal amount of
     Registered Securities and (B) a letter to substantially the same effect as
     paragraphs (i), (ii)(b), (iii), (iv) and (v) of the form of letter set
     forth in Exhibit E to this Indenture, executed by the purchaser is
     delivered to SBCI and the Security Registrar; or

          (ii) the Registered Securities are transferred pursuant to Rule
     144 under the Securities Act of 1933 by the transferor after it has held
     them for more than three years; or

                                       46
<PAGE>

          (iii) the Registered Securities are transferred in any other
     transaction that does not require registration under the Securities Act of
     1933 and an opinion of counsel in form and substance satisfactory to the
     Company is furnished to such effect.

     Registered Securities issued upon registration of transfer of, or
Registered Securities issued in exchange for, Registered Securities bearing
the first legend set forth on the form of definitive Registered Security in
Section 202 shall also bear such legend unless the Company determines that
such transfer is pursuant to Rule 144 under the Securities Act of 1933 or the
Company receives an opinion of counsel in form and substance satisfactory to
it to the effect that such legend may be removed.

     The shares of Common Stock issuable on conversion of Registered
Securities bearing the first legend set forth on the form of definitive
Registered Security in Section 202 shall be subject to the provisions of the
next preceding two paragraphs and the Company shall take all actions
necessary to comply with such provisions.

     At the option of the Holder, Bearer Securities may be exchanged for
Registered Securities, of any authorized denominations and of a like
aggregate principal amount, upon surrender of the Bearer Securities to be
exchanged at an office or agency of the Company designated pursuant to
Section 1002 for such purpose, with all unmatured coupons and all matured
coupons in default appertaining thereto. If the Holder of a Bearer Security
is unable to produce any such unmatured coupon or coupons or matured coupon
or coupons in default, such exchange may be effected if the Bearer Securities
are accompanied by payment in funds reasonably acceptable to the Company in
an amount equal to the face amount of such missing coupon or coupons or the
surrender of such missing coupon or coupons may be waived by the Company and
the Trustee or Principal Paying Agent, if there be furnished to them such
security or indemnity as they may require to save each of them and any agent
of each of them harmless. If thereafter the Holder of such Security shall
surrender to any Paying Agent any such missing coupon in respect of
which such a payment shall have been made, such Holder shall be entitled to
receive the amount of such payment; PROVIDED, HOWEVER, that, except as
otherwise provided in the forms of Security set forth in Section 202,
interest represented by coupons shall be payable only upon presentation and
surrender of those coupons at an office or agency outside the United

                                    47
<PAGE>

States. Notwithstanding the foregoing, in case a Bearer Security is
surrendered in exchange for a Registered Security at an office or agency
designated pursuant to Section 1002 after the close of business at such office
or agency on (i) any Regular Record Date and before the opening of business at
such office or agency on the relevant Interest Payment Date, or (ii) any Special
Record Date and before the opening of business at such office or agency on the
related date for payment of Defaulted Interest, such Bearer Security shall be
surrendered without the coupon relating to such Interest Payment Date or
proposed date of payment, as the case may be.

     At the option of the Holder, Registered Securities may be exchanged for
other Registered Securities of any authorized denominations and of a like
aggregate principal amount, upon surrender of the Securities to be exchanged
at an office or agency of the Company designated pursuant to Section 1002 for
such purpose. Whenever any Registered Securities are so surrendered for
exchange, the Company shall execute, and the Trustee shall authenticate and
deliver, the Registered Securities which the Holder making the exchange is
entitled to receive. Registered Securities, including Registered Securities
received in exchange for Bearer Securities, may not be surrendered in
exchange for Bearer Securities.

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

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

     No service charge shall be made for any registration of transfer or
exchange of Securities, but the Company may require payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed
in connection with any registration of transfer or exchange of Securities,
other than exchanges pursuant to Section 304, 805, 1109 or 1202 not involving
any transfer.

                                      48
<PAGE>

     The Company shall not be required (i) to register the transfer of or
exchange Registered Securities or to exchange Bearer Securities for
Registered Securities for a period of 15 days immediately preceding the date
Securities are selected for redemption by the Principal Paying Agent, or (ii)
to register the transfer of or exchange any Registered Security, or portion
thereof, called for redemption, or (iii) to exchange any Bearer Security
called for redemption, PROVIDED, HOWEVER, that a Bearer Security called for
redemption may be exchanged for a Registered Security which is simultaneously
surrendered to the Security Registrar or Transfer Agent making such exchange
with written instruction for payment consistent with the provisions of this
Indenture.

     SECTION 306.   MUTILATED, DESTROYED, LOST OR STOLEN SECURITIES AND COUPONS.

     If any mutilated Security or a Security with a mutilated coupon
appertaining to it is surrendered to the Principal Paying Agent, the Company
shall execute, and the Trustee shall authenticate and deliver in exchange
therefor a new Security of like tenor and principal amount and bearing a number
not contemporaneously outstanding, with coupons corresponding to the coupons, if
any, appertaining to the surrendered Security.

     If there shall be delivered to the Company and the Trustee or the
Principal Paying Agent (i) evidence to their satisfaction of the destruction,
loss or theft of any Security or coupon, and (ii) such security or indemnity
as may be required by them to save each of them and any agent of either of
them harmless, then, in the absence of notice to the Company or the Trustee
or the Principal Paying Agent that such Security or coupon has been acquired
by a bona fide purchaser, the Company shall execute and upon Company Request
the Trustee shall authenticate and the Company shall cause to have delivered,
in lieu of any such destroyed, lost or stolen Security or in exchange for the
Security to which such coupon appertains (with all appurtenant coupons not
destroyed, lost or stolen), a new Security of like tenor and principal amount
and bearing a number not contemporaneously outstanding, with coupons
corresponding to the coupons, if any, appertaining to such destroyed, lost or
stolen Security or the Security to which such destroyed, lost or stolen
coupon appertains.

     In case any such mutilated, destroyed, lost or stolen Security or
coupon has become or is about to become

                                       49
<PAGE>

due and payable, the Company in its discretion may, instead of issuing a new
Security, pay such Security or coupon; PROVIDED, HOWEVER, that, except as
otherwise provided in the forms of Security set forth in Section 202, the
principal of (and premium, if any) and interest on Bearer Securities shall be
payable only at an office or agency outside the United States and, in the
case of interest (but not in the case of any additional interest payable with
respect to principal and premium, if any, as provided in Section 1004), only
upon presentation and surrender of the coupons appertaining thereto.

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

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

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

     SECTION 307.   PAYMENT OF INTEREST; INTEREST RIGHTS PRESERVED.

     Interest on any Registered Security which is payable, and is punctually
paid or duly provided for, on any Interest Payment Date shall be paid to the
Person in whose name that Security (or one or more Predecessor Securities) is
registered at the close of business on the Regular Record Date for such
interest. In case a Bearer Security is surrendered in exchange for a
Registered Security at an office or agency of the Company designated pursuant
to Section 1002 for the purpose after the close of business (at such office
or agency) on any Regular Record

                                       50
<PAGE>

Date and before the opening of business (at such office or agency) on the
next succeeding Interest Payment Date, such Bearer Security shall be
surrendered without the coupon relating to such Interest Payment Date and
interest will not be payable on such Interest Payment Date in respect of the
Registered Security issued in exchange for such Bearer Security, but will be
payable only to the Holder of such coupon when due.

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

         (1) The Company may elect to make payment of any Defaulted Interest
     to the Persons in whose names the Registered Securities (or their
     respective Predecessor Securities) are registered at the close of
     business on a Special Record Date for the payment of such Defaulted
     Interest, which shall be fixed in the following manner. The Company
     shall notify the Trustee and Principal Paying Agent in writing of the
     amount of Defaulted Interest proposed to be paid on each Registered
     Security and the date of the proposed payment, and at the same time the
     Company shall deposit with the Principal Paying Agent an amount of money
     equal to the aggregate amount proposed to be paid in respect of such
     Defaulted Interest or shall make arrangements satisfactory to the
     Principal Paying Agent for such deposit prior to the date of the
     proposed payment, such money when deposited to be held in trust for the
     benefit of the Persons entitled to such Defaulted Interest as in this
     Clause provided. The Trustee shall fix a Special Record Date for the
     payment of such Defaulted Interest which shall be not more than 15 days
     and not less than 10 days prior to the date of the proposed payment and
     not less than 10 days after the receipt by the Principal Paying Agent of
     the notice of the proposed payment. The Trustee shall promptly notify
     the Company of such Special Record Date and, in the name and at the
     expense of the Company, shall cause notice of the proposed payment of
     such Defaulted Interest and the Special Record Date therefor to
     be mailed, first-class postage prepaid, to

                                      51
<PAGE>

     each Holder of Registered Securities at the address of such Holder as it
     appears in the Security Register, not less than 10 days prior to such
     Special Record Date. Notice of the proposed payment of such Defaulted
     Interest and the Special Record Date therefor having been so mailed,
     such Defaulted Interest shall be paid to the Persons in whose names the
     Registered Securities (or their respective Predecessor Securities) are
     registered at the close of business on such Special Record Date and
     shall no longer be payable pursuant to the following Clause (2). In case
     a Bearer Security is surrendered in exchange for a Registered Security
     at an office or agency of the Company designated pursuant to Section
     1002 for the purpose after the close of business (at such office or
     agency) on any Special Record Date and before the opening of business
     (at such office or agency) on the related proposed date for payment of
     Defaulted Interest, such Bearer Security shall be surrendered without
     the coupon relating to such proposed date of payment and Defaulted
     Interest will not be payable on such proposed date of payment in respect
     of the Registered Security issued in exchange for such Bearer Security,
     but will be payable only to the Holder of such coupon.

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

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

               In the case of any Registered Security which is converted after
any Regular Record Date and on or prior to the next succeeding Interest Payment
Date (other than any Registered Security whose Maturity is prior to such
Interest Payment Date), interest whose Stated Maturity is on such Interest
Payment Date shall be payable on such Interest

                                        52

<PAGE>

Payment Date notwithstanding such conversion, and such interest (whether or
not punctually paid or duly provided for) shall be paid to the Person in whose
name that Registered Security (or one or more Predecessor Securities) is
registered at the close of business on such Regular Record Date. Except as
otherwise expressly provided in the immediately preceding sentence, in the case
of any Security which is converted, interest whose Stated Maturity is after the
date of conversion of such Security shall not be payable.

     SECTION 308. PERSONS DEEMED OWNERS.

     The Company, the Trustee and any agent of the Company or the Trustee may
treat the bearer of any Bearer Security or the Global Security and the bearer
of any coupon as the absolute owner of such Security or coupon for the
purpose of receiving payment thereof or on account thereof and for all other
purposes whatsoever, whether or not such Security or coupon be overdue, and
neither the Company, the Trustee nor any agent of the Company or the Trustee
shall be affected by notice to the contrary. Prior to due presentment of a
Registered Security for registration of transfer, the Company, the Trustee
and any agent of the Company or the Trustee may treat the Person in whose
name such Security is registered as the owner of such Security for the
purpose of receiving payment of principal of (and premium, if any) and
(subject to Section 307) interest on such Security and for all other purposes
whatsoever, whether or not such Security be overdue, and neither the Company,
the Trustee nor any agent of the Company or the Trustee shall be affected by
notice to the contrary.

     SECTION 309. CANCELLATION.

     All Securities and coupons surrendered for payment, redemption, conversion,
registration of transfer or exchange shall, if surrendered to any Person other
than the Trustee or Principal Paying Agent, be delivered to the Trustee or
Principal Paying Agent. All Securities and coupons so delivered shall be
cancelled promptly by the Trustee or Principal Paying Agent. The Company may at
any time deliver to the Trustee or Principal Paying Agent for cancellation any
Securities previously authenticated and delivered hereunder which the Company
may have acquired in any manner whatsoever, and all Securities so delivered
shall be promptly cancelled. No Securities shall be authenticated in lieu of or
in exchange for any Securities cancelled as provided in this Section, except as
expressly

                                     53
<PAGE>

permitted by this Indenture. All cancelled Securities and coupons held by the
Trustee or Principal Paying Agent shall be destroyed and the Trustee or
Principal Paying Agent shall furnish to the Company a certificate with
respect to such destruction, except that the cancelled Global Security and
certificates referred to in Section 304 shall not be destroyed but shall be
delivered to the Company.

     SECTION 310. COMPUTATION OF INTEREST.

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

                                      54
<PAGE>

                                ARTICLE FOUR

                         Satisfaction and Discharge

     SECTION 401. SATISFACTION AND DISCHARGE OF INDENTURE.

     This Indenture shall cease to be of further effect (except as to any
surviving rights of conversion, registration of transfer or exchange of
Securities herein expressly provided for, and any right to receive additional
interest under the second or third paragraph on the face of the forms of
Securities set forth in Section 202), and the Trustee, on demand of and at
the expense of the Company, shall execute proper instruments acknowledging
satisfaction and discharge of this Indenture, when

     (1) either

     (A) all Securities theretofore authenticated and delivered and all
coupons appertaining thereto (other than (i) coupons appertaining to Bearer
Securities surrendered for exchange for Registered Securities and maturing
after such exchange, whose surrender is not required or has been waived as
provided in Section 305, (ii) Securities and coupons which have been
destroyed, lost or stolen and which have been replaced or paid as provided in
Section 306, (iii) coupons appertaining to Securities called for redemption
and maturing after the relevant Redemption Date, whose surrender has been
waived as provided in Section 1107, and (iv) Securities and coupons for whose
payment money has theretofore been deposited in trust or segregated and held
in trust by the Company and thereafter repaid to the Company or discharged
from such trust, as provided in Section 1003) have been delivered to the
Trustee or Principal Paying Agent for cancellation; or

     (B) all such Securities not theretofore delivered to the Trustee or
Principal Paying Agent for cancellation

          (i) have become due and payable, or

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

                                    55
<PAGE>

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

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

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

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

     Notwithstanding the satisfaction and discharge of this Indenture, the
obligations of the Company to the Trustee under Section 606 shall survive
and, if money shall have been deposited with the Trustee or the Principal
Paying Agent pursuant to Clause (1)(B) of this Section, the obligations of
the Trustee under Section 402 and the last paragraph of Section 1003 shall
survive.

     SECTION 402. APPLICATION OF TRUST MONEY.

     Subject to the provisions of the last paragraph of Section 1003, all
money deposited with the Trustee or the Principal Paying Agent pursuant to
Section 401 shall be held in trust and applied by it, in accordance with the
provisions of the Securities, the coupons and this Indenture, to the payment,
through any Paying Agent (including the Company acting as its own Paying
Agent) as the Trustee may determine, to the Persons entitled thereto, of the
principal (and premium, if any) and interest for whose payment such money has
been deposited with the

                                 56
<PAGE>

Trustee or the Principal Paying Agent. All moneys deposited with the Trustee
or the Principal Paying Agent pursuant to Section 401 (and held by it or any
Paying Agent) for the payment of Securities subsequently converted shall be
returned to the Company upon Company Request.

                                  57
<PAGE>

                             ARTICLE FIVE

                               Remedies

     SECTION 501. EVENTS OF DEFAULT.

     "Event of Default", wherever used herein, means any one of the
following events (whatever the reason for such Event of Default and whether it
shall be occasioned by the provisions of Article Thirteen or be voluntary or
involuntary or be effected by operation of law or pursuant to any judgment,
decree or order of any court or any order, rule or regulation of any
administrative or governmental body):

          (1) default in the payment when due of the principal of (or
     premium, if any, on) any Security; or

          (2) default in the payment of any installment of interest or any
     required payment of additional interest on any Security when it becomes due
     and payable, and continuance of such default for a period of 30 days after
     the date when due; or

          (3) default in the performance, or breach, of any covenant or
     warranty of the Company in this Indenture (other than a covenant or
     warranty a default in whose performance or whose breach is elsewhere in
     this Section specifically dealt with) or the Securities, and (unless
     such failure shall not be capable of being remedied) continuance of such
     default or breach for a period of 60 days after there has been given, by
     registered or certified mail, to the Company by the Trustee or to the
     Company and the Trustee by the Holders of at least 25 per cent. in
     principal amount of the Outstanding Securities a written notice
     specifying such default or breach and requiring it to be remedied and
     stating that such notice is a "Notice of Default" hereunder; or

          (4) default under any bond, debenture, note or other evidence of
     indebtedness for money borrowed by the Company or under any mortgage,
     indenture or instrument under which there may be issued or by which
     there may be secured or evidenced any indebtedness for money borrowed by
     the Company, whether such indebtedness now exists or shall hereafter be
     created, which default shall constitute a failure to pay any portion

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     of the principal of such indebtedness when due and payable after the
     expiration of any applicable grace period with respect thereto or shall
     have resulted in such indebtedness becoming or being declared due and
     payable prior to the date on which it would otherwise have become due
     and payable, and the aggregate amount of any and all issues of such
     indebtedness exceeds U.S. $5,000,000 without such indebtedness having
     been discharged, or such acceleration having been rescinded or annulled,
     within a period of 10 days after there shall have been given, by
     registered or certified mail, to the Company by the Trustee or to the
     Company and the Trustee by the Holders of at least 25 per cent. in
     aggregate principal amount of the Outstanding Securities a written
     notice specifying such default and requiring the Company to cause such
     indebtedness to be discharged or cause such acceleration to be rescinded
     or annulled and stating that such notice is a "Notice of Default"
     hereunder; or

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

          (6) the commencement by the Company or any of its Subsidiaries of a
     voluntary case or proceeding under any applicable United States Federal
     or State bankruptcy, insolvency, reorganization or other similar law or
     of any other case or proceeding to be adjudicated a bankrupt or
     insolvent, or the consent by the Company or any of its Subsidiaries to
     the entry of a decree or order for relief in respect of the Company

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     or any of its Subsidiaries in an involuntary case or proceeding under
     any applicable United States Federal or State bankruptcy, insolvency,
     reorganization or other similar law or to the commencement of any
     bankruptcy or insolvency case or proceeding against the Company or any
     of its Subsidiaries, or the filing by the Company or any of its
     Subsidiaries of a petition or answer or consent seeking reorganization
     or relief under any applicable United States Federal or State law, or
     the consent by the Company or any of its Subsidiaries to the filing of
     such petition or to the appointment of or the taking possession by a
     custodian, receiver, liquidator, assignee, trustee, sequestrator or
     similar official of the Company or any of its Subsidiaries or of any
     substantial part of its property, or the making by the Company or any of
     its Subsidiaries of an assignment for the benefit of creditors, or the
     admission by the Company or any of its Subsidiaries in writing of its
     inability to pay its debts generally as they become due, or the taking
     of corporate action by the Company or any of its Subsidiaries in
     furtherance of any such action.

     SECTION 502. ACCELERATION OF MATURITY; RESCISSION AND ANNULMENT.

     If an Event of Default occurs and is continuing, then and in every such
case the Trustee or the Holders of not less than 25 per cent. in principal
amount of the Outstanding Securities may declare the principal of all the
Securities to be due and payable immediately, by a notice in writing to the
Company (and to the Trustee if given by Holders), and upon any such
declaration such principal amount shall become immediately due and payable.

     At any time after such a declaration of acceleration has been made and
before a judgment or decree for payment of the money due has been obtained by
the Trustee as hereinafter in this Article provided, the Holders of a
majority in principal amount of the Outstanding Securities (or 66 2/3 per
cent. in aggregate principal amount of the Securities represented and voting
at a meeting of the Holders duly called in accordance with the provisions of
this Indenture and at which a quorum is present), by written notice to the
Company and the Trustee, may rescind and annul such declaration and its
consequences if

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

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              (A) all overdue interest on all Securities,

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

              (C) to the extent that payment of such interest is lawful,
          interest upon overdue interest at the rate borne by the Securities,
          and

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

          and

          (2) all Events of Default, other than the nonpayment of the
     principal of Securities which have become due solely by such declaration
     of acceleration, have been cured or waived as provided in Section 513.

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

     SECTION 503. COLLECTION OF INDEBTEDNESS AND SUITS FOR ENFORCEMENT BY
                  TRUSTEE.

          The Company covenants that if

          (1) default is made in the payment when due of the principal of (or
     premium, if any, on) any Security, or

          (2) default is made in the payment of any installment of interest
     or any required payment of additional interest on any Security when it
     becomes due and payable and such default continues for a period of 30
     days after the date when due,

the Company will, upon demand of the Trustee, pay to it, for the benefit of
the Holders of such Securities and coupons, the whole amount then due and
payable on such Securities and coupons for principal (and premium, if any) and
interest and, to the extent that payment of such interest shall be legally
enforceable, interest on any

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<PAGE>

overdue principal (and premium, if any) and on any overdue interest, at the
rate borne by the Securities, and, in addition thereto, such further amount as
shall be sufficient to cover the costs and expenses of collection, including the
reasonable compensation, expenses, disbursements and advances of the Trustee,
its agents and counsel.

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

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

     SECTION 504. TRUSTEE MAY FILE PROOFS OF CLAIM.

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

          (i) to file and prove a claim for the whole amount of principal
     (and premium, if any) and interest owing and unpaid in respect of the
     Securities and to file such other papers or documents as may be necessary
     or advisable in order to have the claims of the Trustee (including any
     claim for the reasonable compensation,

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<PAGE>

     expenses, disbursements and advances of the Trustee, its agents and
     counsel) and the Holders of Securities and coupons allowed in such
     judicial proceeding, and

          (ii) to collect and receive any moneys or other property payable
     or deliverable on any such claims and to distribute the same;

and any custodian, receiver, assignee, trustee, liquidator, sequestrator or
other similar official in any such judicial proceeding is hereby authorized by
each Holder of Securities and coupons 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 of Securities and coupons, to pay to the Trustee any
amount due to 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 606.

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

     SECTION 505. TRUSTEE MAY ENFORCE CLAIMS WITHOUT POSSESSION OF
                  SECURITIES OR COUPONS.

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

     SECTION 506. APPLICATION OF MONEY COLLECTED.

     Subject to Article Thirteen and the provisions of the Securities
restricting payments on the Bearer Securities and the coupons in the United
States, any money collected

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<PAGE>

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

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

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

     SECTION 507. LIMITATION ON SUITS.

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

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

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

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

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

          (5) no direction inconsistent with such written request has been
     given to the Trustee during such

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<PAGE>

     60-day period by the Holders of a majority in principal amount of the
     Outstanding Securities (or such lesser amount as shall have acted at a
     meeting pursuant to the provisions of this Indenture, PROVIDED that such
     lesser amount is more than the principal amount of the Outstanding
     Securities whose Holders shall have made such written request);

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

     SECTION 508.   UNCONDITIONAL RIGHT OF HOLDERS TO RECEIVE PRINCIPAL, PREMIUM
                    AND INTEREST AND TO CONVERT.

     Notwithstanding any other provision in this Indenture, but subject to
Article Thirteen, the Holder of any Security or coupon shall have the right,
which is absolute and unconditional, to receive payment of the principal of
(and premium, if any) and (subject to Section 307) interest on such Security
or payment of such coupon at the times, places and rate, and in the coin or
currency expressed in such Security or coupon (or, in the case of redemption,
on the Redemption Date) and to convert such Security in accordance with
Article Twelve, or to institute suit for the enforcement of any such payment
or right to convert, and such rights shall not be impaired or affected
without the consent of such Holder.

     SECTION 509. RESTORATION OF RIGHTS AND REMEDIES.

     If the Trustee or any Holder of a Security or coupon has instituted any
proceeding to enforce any right or remedy under this Indenture and such
proceeding has been discontinued or abandoned for any reason, or has been
determined adversely to the Trustee or to such Holder, then and in every such
case, subject to any determination in such proceeding, the Company, the
Trustee and the Holders of Securities and coupons shall be restored severally
and respectively to their former positions hereunder, and thereafter all
rights and remedies of the Trustee and the

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<PAGE>


Holders shall continue as though no such proceeding had been instituted.

     SECTION 510. RIGHTS AND REMEDIES CUMULATIVE.

     Except as otherwise provided in Section 507 or with respect to the
replacement or payment of mutilated, destroyed, lost or stolen Securities or
coupons in the last paragraph of Section 306, no right or remedy herein
conferred upon or reserved to the Trustee or to the Holders of Securities or
coupons is intended to be exclusive of any other right or remedy, and every
right and remedy shall, to the extent permitted by law, be cumulative and in
addition to every other right and remedy given hereunder or now or hereafter
existing at law or in equity or otherwise. The assertion or employment of any
right or remedy hereunder, or otherwise, shall not prevent the concurrent
assertion or employment of any other appropriate right or remedy.

     SECTION 511. DELAY OR OMISSION NOT WAIVER.

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

     SECTION 512. CONTROL BY HOLDERS OF SECURITIES.

     The Holders of a majority in principal amount of the Outstanding
Securities (or such lesser amount as shall have acted at a meeting pursuant
to the provisions of this Indenture) shall have the right to direct the time,
method and place of conducting any proceeding for any remedy available to the
Trustee or exercising any trust or power conferred on the Trustee, PROVIDED
that

          (1) such direction shall not be in conflict with any rule of law
    or with this Indenture, including, but not limited to Section 507 and 602(e)
    hereof, and

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

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<PAGE>


     SECTION 513. WAIVER OF PAST DEFAULTS.

     The Holders of not less than a majority in principal amount of the
Outstanding Securities (or such lesser amount as shall have acted at a
meeting pursuant to the provisions of this Indenture) may on behalf of the
Holders of all the Securities and coupons waive any past default hereunder
and its consequences, except a default

          (1) in the payment of the principal of (or premium, if any) or
     interest on any Security, or

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

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

     SECTION 514. UNDERTAKING FOR COSTS.

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

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<PAGE>

Redemption Date) or for the enforcement of the right to convert any Security
in accordance with Article Twelve.

         SECTION 515. WAIVER OF STAY OR EXTENSION LAWS.

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

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                                 ARTICLE SIX

                                 The Trustee

         SECTION 601. CERTAIN DUTIES AND RESPONSIBILITIES.

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

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

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

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

        (c) No provision of this Indenture shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent
failure to act, or its own wilful misconduct, EXCEPT that

        (1) this Subsection shall not be construed to limit the effect of
    Subsection (a) of this Section;

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

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<PAGE>

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

         (4) no provision of this Indenture shall require the Trustee to
    expend or risk its own funds or otherwise incur any financial liability
    in the performance of any of its duties hereunder, or in the exercise of
    any of its rights or powers, if it shall have reasonable grounds for
    believing that repayment of such funds or adequate indemnity against such
    risk or liability is not reasonably assured to it.

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

         SECTION 602. CERTAIN RIGHTS OF TRUSTEE.

         Subject to the provisions of Section 601:

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

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

         (c) whenever in the administration of this Indenture the Trustee
    shall deem it desirable that a matter be proved or established prior to
    taking, suffering or omitting any action hereunder, the

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<PAGE>

    Trustee (unless other evidence be herein specifically prescribed) may, in
    the absence of bad faith on its part, rely upon an Officers' Certificate;

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

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

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

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

         SECTION 603. NOT RESPONSIBLE FOR RECITALS OR ISSUANCE OF SECURITIES.

         The recitals contained herein and in the Securities (except the
Trustee's certificates of authentication) and in the coupons shall be taken
as the statements of the Company, and the Trustee assumes no responsibility
for their correctness. The Trustee makes no representations

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<PAGE>

as to the validity or sufficiency of this Indenture or of the Securities or
coupons. The Trustee shall not be accountable for the use or application by
the Company of Securities or the proceeds thereof.

         SECTION 604. MAY HOLD SECURITIES, ACT AS TRUSTEE UNDER OTHER
                      INDENTURES.

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

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

         SECTION 605. MONEY HELD IN TRUST.

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

         SECTION 606. COMPENSATION AND REIMBURSEMENT.

         The Company agrees:

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

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

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<PAGE>

    disbursement or advance as may be attributable to its negligence or bad
    faith; and

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

         As security for the performance of the obligations of the Company
under this Section the Trustee shall have a claim prior to the Securities
upon all property and funds held or collected by the Trustee as such, except
funds held in trust (whether or not segregated) for the payment of principal
of (and premium, if any) or interest on Securities.

         SECTION 607. CORPORATE TRUSTEE REQUIRED; ELIGIBILITY.

         There shall at all times be a Trustee hereunder which shall be a
corporation organized and doing business under the laws of the United States
of America, any State thereof or the District of Columbia, authorized under
such laws to exercise corporate trust powers, having a combined capital and
surplus of at least U.S. $50,000,000, subject to supervision or examination
by Federal or State authority and having a corporate trust office in the
Borough of Manhattan, The City of New York. If such corporation publishes
reports of condition at least annually, pursuant to law or to the
requirements of said supervising or examining authority, then for the
purposes of this Section, the combined capital and surplus of such
corporation shall be deemed to be its combined capital and surplus as set
forth in its most recent report of condition so published. If at any time the
Trustee shall cease to be eligible in accordance with the provisions of this
Section, it shall resign immediately in the manner and with the effect
hereinafter specified in this Article.

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<PAGE>

         SECTION 608. RESIGNATION AND REMOVAL; APPOINTMENT OF SUCCESSOR.

         (a) No resignation or removal of the Trustee and no appointment of a
successor Trustee pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee in accordance with the
applicable requirements of Section 609.

         (b) The Trustee may resign at any time giving written notice thereof
to the Company. If the instrument of acceptance by a successor Trustee
required by Section 609 shall not have been delivered to the Trustee within
30 days after the giving of such notice of resignation, the resigning Trustee
may petition any court of competent jurisdiction for the appointment of a
successor Trustee.

         (c) The Trustee may be removed at any time by Act of the Holders of
a majority in principal amount of the Outstanding Securities (or such lesser
amount as shall have acted at a meeting pursuant to the provisions of this
Indenture), delivered to the Trustee and the Company.

         (d) If at any time:

         (1) the Trustee shall cease to be eligible under Section 607 and
    shall fail to resign after written request therefor by the Company or by
    any Holder of a Security who has been a bona fide Holder of a Security
    for at least six months, or

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

then, in any such case, (i) the Company by a Board Resolution may remove the
Trustee, or (ii) subject to Section 514, any Holder of a Security who has
been a bona fide Holder of a Security for at least six months may, on behalf
of himself and all others similarly situated, petition any court of competent
jurisdiction for the removal of the Trustee and the appointment of a
successor Trustee.

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         (e) If the Trustee shall resign, be removed or become incapable of
acting, or if a vacancy shall occur in the office of Trustee for any cause,
the Company, by a Board Resolution, shall promptly appoint a successor
Trustee and shall comply with the applicable requirements of Section 609. If,
within one year after such resignation, removal or incapability, or the
occurrence of such vacancy, a successor Trustee shall be appointed by Act of
the Holders of a majority in principal amount of the Outstanding Securities
(or such lesser amount as shall have acted at a meeting pursuant to the
provisions of this Indenture) delivered to the Company and the retiring
Trustee, the successor Trustee so appointed shall, forthwith upon its
acceptance of such appointment in accordance with the applicable requirements
of Section 609, become the successor Trustee and supersede the successor
Trustee appointed by the Company. If no successor Trustee shall have been so
appointed by the Company or the Holders of Securities and accepted
appointment in the manner required by Section 609, any Holder of a Security
who has been a bona fide Holder of a Security for at least six months may, on
behalf of himself and all others similarly situated, petition any court of
competent jurisdiction for the appointment of a successor Trustee.

         (f) The Company shall give notice of each resignation and each
removal of the Trustee and each appointment of a successor Trustee to the
Holders of Securities in the manner provided in Section 105. Each notice
shall include the name of the successor Trustee and the address of its
Corporate Trust Office.

         SECTION 609. ACCEPTANCE OF APPOINTMENT BY SUCCESSOR.

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

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request of any such successor Trustee, the Company shall execute any and all
instruments for more fully and certainly vesting in and confirming to such
successor Trustee all such rights, powers and trusts.

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

         SECTION 610. MERGER, CONVERSION, CONSOLIDATION OR SUCCESSION TO
                      BUSINESS.

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

         SECTION 611. APPOINTMENT OF AUTHENTICATING AGENT.

         The Trustee may appoint an Authenticating Agent or Agents which
shall be authorized to act on behalf of the Trustee to authenticate
Securities issued upon original issue and upon exchange, registration or
transfer, partial conversion or partial redemption or pursuant to Section 304
or Section 306, and Securities so authenticated shall be entitled to the
benefits of this Indenture and shall be valid and obligatory for all purposes
as if authenticated by the Trustee hereunder. Wherever reference is made in
this Indenture to the authentication and delivery or endorsement of
Securities by the Trustee or the Trustee's certificate of authentication,
such reference shall be deemed to include authentication and delivery or
endorsement on behalf of the Trustee by an Authenticating Agent and a
certificate of authentication executed on behalf of the Trustee by an
Authenticating Agent. Each Authenticating Agent shall be acceptable to the
Company and shall at all times be a corporation organized and doing business
under the laws of

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the United States of America, any State thereof or the District of Columbia,
authorized under such laws to exercise corporate trust powers and to act as
Authenticating Agent, having a combined capital and surplus of not less than
U.S. $50,000,000, subject to supervision or examination by Federal or State
authority and having its corporate trust office in the Borough of Manhattan,
The City of New York. If such Authenticating Agent publishes reports of
condition at least annually, pursuant to law or to the requirements of said
supervising or examining authority, then for the purposes of this Section
611, the combined capital and surplus of such Authenticating Agent shall be
deemed to be its combined capital and surplus as set forth in its most recent
report of condition so published. If at any time an Authenticating Agent
shall cease to be eligible in accordance with the provisions of this Section,
such Authenticating Agent shall resign immediately in the manner and with the
effect specified in this Section.

         Any corporation into which an Authenticating Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, conversion or consolidation to which such Authenticating
Agent shall be a party, or any corporation succeeding to all or substantially
all the corporate trust business of an Authenticating Agent, shall continue
to be an Authenticating Agent, provided such corporation shall be otherwise
eligible under this Section 611, without the execution or filing of any paper
or any further act on the part of the Trustee or the Authenticating Agent.

         An Authenticating Agent may resign at any time by giving written
notice thereof to the Trustee and to the Company. The Trustee may at any time
terminate the agency of an Authenticating Agent by giving written notice
thereof to such Authenticating Agent and to the Company. Upon receiving such
a notice of resignation or upon such a termination, or in case at any time
such Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor
Authenticating Agent which shall be acceptable to the Company and shall
provide notice of such appointment to all Holders of Securities in the manner
provided in Section 105. Any successor Authenticating Agent upon acceptance
of its appointment hereunder shall become vested with all the rights, powers
and duties of its predecessor hereunder with like effect as if originally
named as an Authenticating Agent. No successor Authenticating Agent

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<PAGE>

shall be appointed unless eligible under the provisions of this Section.

         The Company agrees to pay to each Authenticating Agent from time to
time reasonable compensation for its services under this Section 611.

         If an appointment is made pursuant to this Section, the Securities
may have endorsed thereon, in addition to the Trustee's certificate of
authentication, an alternate certificate of authentication in the following
form:

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

                                       BANKERS TRUST COMPANY
                                         as Trustee


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

                                       As Authenticating Agent


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

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                                ARTICLE SEVEN

            Consolidation, Merger, Conveyance, Transfer or Lease

         SECTION 701. COMPANY MAY CONSOLIDATE, ETC., ONLY ON CERTAIN TERMS.

         The Company shall not consolidate with or merge into any other
Person or convey, transfer or lease all or substantially all of its
properties and assets to any Person, unless:

         (1) the Person formed by such consolidation or into which the
    Company is merged or the Person which acquires by conveyance or transfer,
    or which leases, the properties and assets of the Company substantially
    as an entirety shall be a corporation, organized and validly existing
    under the laws of the United States of America, any State thereof or the
    District of Columbia, shall expressly assume, by an indenture
    supplemental hereto, executed and delivered to the Trustee, in form
    satisfactory to the Trustee, the due and punctual payment of the
    principal of (and premium, if any) and interest (including all additional
    interest payable pursuant to Section 1004) on all the Securities and the
    performance of every covenant of this Indenture on the part of the
    Company to be performed or observed and shall have provided for
    conversion rights in accordance with Section 1211, and shall expressly
    waive, by such indenture supplemental hereto, any right to redeem the
    Securities under circumstances in which the Company would not have been
    entitled to redeem the Securities if such consolidation, merger,
    conveyance, transfer or lease had not occurred;

         (2) immediately after giving effect to such transaction, no Event of
    Default and no event which, after notice or lapse of time or both, would
    become an Event of Default, shall have happened and be continuing; and

         (3) the Company shall have delivered to the Trustee an Officers'
    Certificate and an Opinion of Counsel, each stating that such
    consolidation, merger, conveyance, transfer or lease and, if a
    supplemental indenture is required in connection with such transaction,
    such supplemental indenture comply with this

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    Article and that all conditions precedent herein provided for relating to
    such transaction have been complied with.

         SECTION 702. SUCCESSOR SUBSTITUTED.

         Upon any consolidation of the Company with, or merger of the Company
into, any other Person or any conveyance, transfer or lease of the properties
and assets of the Company substantially as an entirety in accordance with
Section 701, the successor corporation formed by such consolidation or into
which the Company is merged or to which such conveyance, transfer or lease is
made shall succeed to, and be substituted for, and may exercise every right
and power of, the Company under this Indenture with the same effect as if
such successor corporation had been named as the Company herein, and
thereafter, except in the case of a lease, the predecessor corporation shall
be relieved of all obligations and covenants under this Indenture and the
Securities and coupons.

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                                ARTICLE EIGHT

                           Supplemental Indentures

         SECTION 801. SUPPLEMENTAL INDENTURES WITHOUT CONSENT OF HOLDERS.

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

         (1) to evidence the succession of another corporation to the Company
    and the assumption by any such successor of the covenants of the Company
    herein in the Securities and in the coupons; or

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

         (3) to relax or eliminate the restrictions on payment of principal
    of (and premium, if any) and interest on Bearer Securities in the United
    States under the circumstances described in the last sentence of the
    first paragraph of the face of the form of Bearer Securities set forth in
    Section 202; or

         (4) to make provision with respect to the conversion rights of
    Holders of Securities pursuant to Section 1211; or

         (5) to cure any ambiguity, to correct or supplement any provision
    herein which may be inconsistent with any other provision herein, or to
    make any other provisions with respect to matters or questions arising
    under this Indenture, PROVIDED such action pursuant to this clause (5)
    shall not adversely affect the interest of the Holders of Securities or
    coupons in any material respect.

         SECTION 802. SUPPLEMENTAL INDENTURES WITH CONSENT OF HOLDERS.

         With the consent of the Holders of not less than a majority in
principal amount of the Outstanding Securities

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<PAGE>

(or such lesser amount as shall have acted at a meeting pursuant to the
provisions of this Indenture), by Act of said Holders delivered to the
Company and the Trustee, the Company, when authorized by a Board Resolution,
and the Trustee may enter into an indenture or indentures supplemental hereto
for the purpose of adding any provisions to or changing in any manner or
eliminating any of the provisions of this Indenture or of modifying in any
manner the rights of the Holders of the Securities or coupons under this
Indenture; PROVIDED, HOWEVER, that no such supplemental indenture shall,
without the consent of the Holder of each Outstanding Security or coupon
affected thereby,

         (1) change the Stated Maturity of the principal of, or any
    instalment of interest on, any Security, or reduce the principal amount
    thereof or the rate of interest thereon or any premium payable upon the
    redemption thereof, or change the obligation of the Company to pay
    additional interest pursuant to Section 1004 or change the coin or currency
    in which any Security or any premium or the interest thereon is payable, or
    impair the right to institute suit for the enforcement of any such payment
    on or after the Stated Maturity thereof (or, in the case of redemption, on
    or after the Redemption Date), or adversely affect the right to convert any
    Securities as provided in Article Twelve or modify the provisions of this
    Indenture with respect to the subordination of the Securities in a manner
    adverse to the Holders, or

         (2) reduce the requirements of Section 904 for quorum or voting, or
    reduce the percentage in principal amount of the Outstanding Securities
    the consent of whose Holders is required for any such supplemental
    indenture or the consent of whose Holders is required for any waiver (or
    compliance with certain provisions of this Indenture or certain defaults
    hereunder and their consequences) provided for in this Indenture, or

         (3) change the obligation of the Company to maintain an office or
    agency in the Borough of Manhattan, The City of New York, and in a
    European city pursuant to Section 1002, or

         (4) modify any of the provisions of this Section, Section 513 or
    Section 1009, except to increase any such percentage or to provide that
    certain other provisions of this Indenture cannot be modified or waived
    without the consent of the Holder of each Outstanding Security affected
    thereby.

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<PAGE>

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

         SECTION 803. EXECUTION OF SUPPLEMENTAL INDENTURES.

         In executing, or accepting the additional trusts created by, any
supplemental indenture permitted by this Article or the modifications thereby
of the trusts created by this Indenture, the Trustee shall be entitled to
receive, and (subject to Section 601) shall be fully protected in relying
upon, an Opinion of Counsel stating that the execution of such supplemental
indenture is authorized or permitted by this Indenture. The Trustee may, but
shall not be obligated to, enter into any such supplemental indenture which
affects the Trustee's own rights, duties or immunities under this Indenture
or otherwise.

         SECTION 804. EFFECT OF SUPPLEMENTAL INDENTURES.

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

         SECTION 805. REFERENCE IN SECURITIES TO SUPPLEMENTAL INDENTURES.

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

         SECTION 806. NOTICE OF SUPPLEMENTAL INDENTURES.

         Promptly after the execution by the Company and the Trustee of any
supplemental indenture pursuant to the

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<PAGE>

provisions of Section 802, the Company shall give notice, setting forth in
general terms the substance of such supplemental indenture, in the manner
provided in Section 105. Any failure of the Company to give such notice, or
any defect therein, shall not in any way impair or affect the validity of any
such supplemental indenture.

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<PAGE>

                                ARTICLE NINE

                      Meetings of Holders of Securities

         SECTION 901. PURPOSES FOR WHICH MEETINGS MAY BE CALLED.

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

         SECTION 902. CALL, NOTICE AND PLACE OF MEETINGS.

         (a) The Trustee may at any time call a meeting of Holders of
Securities for any purpose specified in Section 901, to be held at such time
and at such place in the Borough of Manhattan, The City of New York, or in
London as the Trustee shall determine. Notice of every meeting of Holders of
Securities, setting forth the time and the place of such meeting and in
general terms the action proposed to be taken at such meeting, shall be
given, in the manner provided in Section 105, not less than 21 nor more than
180 days prior to the date fixed for the meeting.

         (b)  In case at any time the Company, pursuant to a Board
Resolution, or the Holders of at least 10 per cent. in principal amount of
the Outstanding Securities shall have requested the Trustee to call a meeting
of the Holders of Securities for any purpose specified in Section 901, by
written request setting forth in reasonable detail the action proposed to be
taken at the meeting, and the Trustee shall not have made the first
publication of the notice of such meeting within 21 days after receipt of
such request or shall not thereafter proceed to cause the meeting to be held
as provided herein, then the Company or the Holders of Securities in the
amount above specified, as the case may be, may determine the time and the
place in the Borough of Manhattan, The City of New York, or in London for
such meeting and may call such meeting for such purposes by giving notice
thereof as provided in subsection (a) of this Section.

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<PAGE>

         SECTION 903. PERSONS ENTITLED TO VOTE AT MEETINGS.

         To be entitled to vote at any meeting of Holders of Securities, a
Person shall be (1) a Holder of one or more Outstanding Securities, or (2) a
Person appointed by an instrument in writing as proxy for a Holder or Holders
of one or more Outstanding Securities by such Holder or Holders. The only
Persons who shall be entitled to be present or to speak at any meeting of
Holders shall be the Persons entitled to vote at such meeting and their
counsel, and representatives of the Trustee and its counsel and any
representatives of the Company and its counsel.

         SECTION 904. QUORUM; ACTION.

         The Persons entitled to vote a majority in principal amount of the
Outstanding Securities shall constitute a quorum. In the absence of a quorum
within 30 minutes of the time appointed for any such meeting, the meeting
shall, if convened at the request of Holders of Securities, be dissolved. In
any other case the meeting may be adjourned for a period of not less than 10
days as determined by the chairman of the meeting prior to the adjournment of
such meeting. In the absence of a quorum at any such adjourned meeting, such
adjourned meeting may be further adjourned for a period of not less than 10
days as determined by the chairman of the meeting prior to the adjournment of
such adjourned meeting. Notice of the reconvening of any adjourned meeting
shall be given as provided in Section 902(a), except that such notice need be
given only once not less than five days prior to the date on which the
meeting is scheduled to be reconvened. Notice of the reconvening of an
adjourned meeting shall state expressly the percentage of the principal
amount of the Outstanding Securities which shall constitute a quorum.

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

         Except as limited by the proviso to Section 802, any modifications,
amendments or waivers to this Indenture or the terms and conditions of the
Securities or coupons shall require the lesser of (i) the written consent of
the holders of a majority in principal amount of the Outstanding

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<PAGE>

Securities or (ii) the approval of persons entitled to vote a majority of the
principal amount of such Securities represented and voting at a meeting of
the Holders duly called in accordance with the provisions hereof and at which
a quorum is present.

         Any modification, amendment or waiver approved in accordance with
the provisions of the next preceding paragraph shall be binding on all the
Holders of Securities and coupons, whether or not present or represented at
the meeting.

         SECTION 905. DETERMINATION OF VOTING RIGHTS; CONDUCT AND ADJOURNMENT
                      OF MEETINGS.

         (a) Notwithstanding any other provisions of this Indenture, the
Trustee may make such reasonable regulations as it may deem advisable for any
meeting of Holders of Securities in regard to proof of the holding of
Securities and of the appointment of proxies and in regard to the appointment
and duties of inspectors of votes, the submission and examination of proxies,
certificates and other evidence of the right to vote, and such other matters
concerning the conduct of the meeting as it shall deem appropriate. Except as
otherwise permitted or required by any such regulations, the holding of
Securities shall be proved in the manner specified in Section 103 and the
appointment of any proxy shall be proved in the manner specified in Section
103 or by having the signature of the person executing the proxy witnessed or
guaranteed by any trust company, bank or banker authorized by Section 103 to
certify to the holding of Bearer Securities. Such regulations may provide
that written instruments appointing proxies, regular on their face, may be
presumed valid and genuine without the proof specified in Section 103 or
other proof.

         (b) The Trustee shall, by an instrument in writing, appoint a
temporary chairman of the meeting, unless the meeting shall have been called
by the Company or by Holders of Securities as provided in Section 902(b), in
which case the Company or the Holders of Securities calling the meeting, as
the case may be, shall in like manner appoint a temporary chairman. A
permanent chairman and a permanent secretary of the meeting shall be elected
by vote of the Persons entitled to vote a majority in principal amount of the
Outstanding Securities represented at the meeting.

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<PAGE>

         (c) At any meeting each Holder of a Security or proxy shall be
entitled to one vote for each U.S. $5,000 principal amount of Securities held
or represented by him; PROVIDED, HOWEVER, that no vote shall be cast or
counted at any meeting in respect of any Security challenged as not
Outstanding and ruled by the chairman of the meeting to be not Outstanding.
The chairman of the meeting shall have no right to vote, except as a Holder
of a Security or proxy.

         (d) Any meeting of Holders of Securities duly called pursuant to
Section 902 at which a quorum is present may be adjourned from time to time
by Persons entitled to vote a majority in principal amount of the Outstanding
Securities represented at the meeting; and the meeting may be held as so
adjourned without further notice.

         SECTION 906. COUNTING VOTES AND RECORDING ACTION OF MEETINGS.

         The vote upon any resolution submitted to any meeting of Holders of
Securities shall be by written ballots on which shall be subscribed the
signatures of the Holders of Securities or of their representatives by proxy
and the principal amounts and serial numbers of the Outstanding Securities
held or represented by them. The permanent chairman of the meeting shall
appoint two inspectors of votes who shall count all votes cast at the meeting
for or against any resolution and who shall make and file with the secretary
of the meeting their verified written reports in duplicate of all votes cast
at the meeting. A record, at least in duplicate, of the proceedings of each
meeting of Holders of Securities shall be prepared by the secretary of the
meeting and there shall be attached to said record the original reports of
the inspectors of votes on any vote by ballot taken thereat and affidavits by
one or more persons having knowledge of the facts setting forth a copy of the
notice of the meeting and showing that said notice was given as provided in
Section 902 and, if applicable, Section 904. Each copy shall be signed and
verified by the affidavits of the permanent chairman and secretary of the
meeting and one such copy shall be delivered to the Company and another to
the Trustee to be preserved by the Trustee, the latter to have attached
thereto the ballots voted at the meeting. Any record so signed and verified
shall be conclusive evidence of the matters therein stated.

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<PAGE>

                                 ARTICLE TEN

                                  Covenants

         SECTION 1001.  PAYMENT OF PRINCIPAL, PREMIUM AND INTEREST.

         The Company will duly and punctually pay the principal of (and
premium, if any) and interest on the Securities in accordance with the terms
of the Securities, the coupons appertaining thereto and this Indenture. The
interest due on the Bearer Securities on or before Maturity, other than
additional interest payable as provided in Section 1004 in respect of
principal of (or premium, if any, on) such a Security, shall be payable only
upon presentation and surrender of the several coupons for such interest
installments as are evidenced thereby as they severally mature.

         SECTION 1002. MAINTENANCE OF OFFICES OR AGENCIES.

         Pursuant to the Paying Agency Agreement, the Company has appointed
(1) the Principal Office of Morgan Guaranty Trust Company of New York as its
agent in the Borough of Manhattan, The City of New York, where Registered
Securities may be presented or surrendered for payment, where Bearer
Securities and coupons may be presented or surrendered for payment in the
circumstance described in the next sentence (and not otherwise), where
Securities may be surrendered for registration of transfer or exchange, where
Registered Securities may be surrendered for conversion, where Bearer
Securities may be surrendered for conversion in the circumstance described in
the next sentence (and not otherwise) and where notices to or upon the
Company in respect of the Securities and coupons and this Indenture may be
served and demands to or upon the Company with respect to Registered
Securities may be made, (2) the main office of Banque Internationale a
Luxembourg S.A. in Luxembourg as its agent outside the United States where,
subject to any applicable laws or regulations, Securities and coupons may be
presented and surrendered for payment and where Securities may be presented
for registration of transfer or exchange and where demands upon the Company
in respect of Bearer Securities and coupons may be made and (3) the main
office of Morgan Guaranty Trust Company of New York in Brussels and Banque
Internationale a Luxembourg S.A. in Luxembourg as its agents outside the
United States where, subject to any applicable laws or regulations, Securities

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<PAGE>

may be surrendered for conversion. As provided in the forms of Security set
forth in Section 202, (i) payment of principal of and premium, if any, and
interest on Bearer Securities and payment of any additional interest payable
on Bearer Securities pursuant to Section 1004 may be made at the Principal
Office of the Principal Paying Agent in the Borough of Manhattan, The City of
New York, if (but only if) payment of the full amount of such principal,
premium, interest or additional interest, as the case may be, at all offices
outside the United States maintained for the purpose by the Company in
accordance with this Indenture is illegal or effectively precluded because of
the imposition of exchange controls or other similar restrictions on the full
payment or receipt of such amounts in Dollars and (ii) Bearer Securities may
be surrendered for conversion at such office if (but only if) conversion at
all offices outside the United States maintained for the purpose by the
Company in accordance with this Indenture is illegal or effectively precluded
because of the imposition of exchange controls or other similar restrictions.

         In addition, the Company has appointed the main offices of Morgan
Guaranty Trust Company in London, Algemene Bank Nederland N.V. in Amsterdam
and Swiss Bank Corporation in Basel as additional Paying Agents for the
payment of principal of (and premium, if any) and interest on the Bearer
Securities.

         The Company may at any time and from time to time vary or terminate
the appointment of any such agent or appoint any additional agents for any or
all of such purposes; PROVIDED, HOWEVER, that until the Securities have been
delivered to the Trustee or the Principal Paying Agent for cancellation, or
moneys sufficient to pay the principal of and premium, if any, and interest
on the Securities have been made available for payment and either paid or
returned to the Company pursuant to the provisions of Section 1003, the
Company will maintain (1) in the Borough of Manhattan, The City of New York,
an office or agency where Registered Securities may be presented or
surrendered for payment, where Bearer Securities and coupons may be presented
or surrendered for payment in the circumstance described in the last sentence
of the first paragraph of this Section (and not otherwise), where Securities
may be surrendered for registration of transfer or exchange, where Registered
Securities may be surrendered for conversion, where Bearer Securities may be
surrendered for conversion in the circumstances described in the last
sentence of the first paragraph of this Section (and not otherwise), and where

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<PAGE>

notices to or upon the Company in respect of the Securities and coupons and
this Indenture may be served and demands to or upon the Company with respect
to Registered Securities may be made and (2) subject to any laws or
regulations applicable thereto, in a European city an office or agency where
Securities and coupons may be presented or surrendered for payment and where
Securities may be presented for registration of transfer or exchange and
surrendered for conversion and were demands upon the Company in respect of
Bearer Securities and coupons may be made; and PROVIDED, FURTHER, that so
long as the Securities are listed on the Luxembourg Stock Exchange and such
Exchange shall so require, the Company will maintain a Paying Agent and
Conversion Agent in Luxembourg. The Company will give prompt written notice
to the Trustee and the Principal Paying Agent and the Holders of the
appointment or termination of any such agent and of the location and any
change in the location of any such office or agency.

         If at any time the Company shall fail to maintain any such required
office or agency in the Borough of Manhattan, The City of New York, or in a
European city, or shall fail to furnish the Trustee with the address thereof,
presentations and surrenders of Registered Securities may be made (subject to
the limitations described in the preceding paragraph) at and notices and
demands may be served on and Registered Securities may be surrendered for
conversion to the Corporate Trust Office of the Trustee, and Bearer
Securities and coupons may be presented and surrendered for payment or
surrendered for conversion to the Trustee at its main office in London, and
the Company hereby appoints the same as its agent to receive such
presentations, surrenders, notices and demands.

         SECTION 1003. MONEY FOR SECURITY PAYMENTS TO BE HELD IN TRUST.

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

         Whenever the Company shall have one or more Paying Agents, it will,
on or prior to each due date of the

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principal of (and premium, if any) or interest on any Securities, deposit
with a Paying Agent a sum sufficient to pay the principal (and premium, if
any) or interest so becoming due, such sum to be held in trust for the
benefit of the Persons entitled to such principal, premium or interest, and
(unless such Paying Agent is the Trustee) the Company will promptly notify
the Trustee of its action or failure so to act.

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

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

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

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

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

         Any money deposited with the Trustee or any Paying Agent, or then
held by the Company, in trust for the payment of the principal of (and
premium, if any) or interest on any Security and remaining unclaimed for two
years after such principal (and premium, if any) or interest has become due
and payable shall be repaid to the Company on Company Request, or (if then
held by the Company) shall be dis-

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charged from such trust; and the Holder of such Security or any coupon
appertaining thereto shall thereafter, as an unsecured general creditor, look
only to the Company for payment thereof, and all liability of the Trustee or
such Paying Agent with respect to such trust money, and all liability of the
Company as trustee thereof, shall thereupon cease; PROVIDED, HOWEVER, that the
Trustee or such Paying Agent, before being required to make any such
repayment, may at the expense of the Company cause notice to be given as
provided in Section 105, except that such notice need be given only once,
that such money remains unclaimed and that, after a date specified therein,
which shall not be less than 30 days from the latest date of such notice, any
unclaimed balance of such money then remaining will be repaid to the Company.

         SECTION 1004. ADDITIONAL INTEREST.

         The Company will pay as additional interest to the Holder of any
Security or any coupon appertaining thereto any additional interest which may
become payable as provided in the second paragraph on the face of the forms
of Securities set forth in Section 202 and any additional interest which may
become payable as provided in the fourth paragraph on the face of the forms
of Securities set forth in Section 202. Whenever in this Indenture there is
mentioned, in any context, the payment of the principal of (or premium, if
any) or interest on, or in respect of, any Security or any coupon, such
mention shall be deemed to include mention of the payment of additional
interest provided for in this Section to the extent that, in such context,
additional interest is, was or would be payable in respect thereof pursuant
to the provisions of this Section and express mention of the payment of
additional interest (if applicable) in any provision hereof shall not be
construed as excluding additional interest in those provisions hereof where
such express mention is not made.

         At least 10 days prior to May 21, 1988 (and at least 10 days prior
to each May 21 thereafter if there has been any change with respect to the
matters set forth in the below-mentioned Officers' Certificate) the Company
will furnish the Trustee and the Principal Paying Agent in the Borough of
Manhattan, The City of New York, with an Officers' Certificate instructing
the Trustee and the Principal Paying Agent whether such payment of principal
of (and premium, if any) or interest on the Securities shall be made to
Holders of Securities or coupons who are United States Aliens without
withholding for or on account of any

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tax, assessment or other governmental charge described in the second
paragraph on the face of the forms of Securities set forth in Section 202. If
any such withholding shall be required, then such Officers' Certificate shall
specify by country the amount, if any, required to be withheld on such
payments to such Holders of Securities or coupons and the Company will pay to
the Trustee or such Paying Agent the additional interest required by this
Section to be paid in the event of any such withholding. The Company
covenants to indemnify the Trustee, the Principal Paying Agent and any other
Paying Agent for, and to hold them harmless against, any loss, liability or
expense reasonably incurred without negligence or bad faith on their part
arising out of or in connection with actions taken or omitted by any of them
in reliance on any Officers' Certificate furnished pursuant to this Section.

         SECTION 1005. CORPORATE EXISTENCE.

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

         SECTION 1006. MAINTENANCE OF PROPERTIES.

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

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         SECTION 1007. PAYMENT OF TAXES AND OTHER CLAIMS.

         The Company will pay or discharge or cause to be paid or discharged
(1) all taxes, assessments and governmental charges levied or imposed upon
the Company or any Subsidiary or upon the income, profits or property of the
Company or any Subsidiary, and (2) all lawful claims for labor, materials and
supplies which, if unpaid, might by law become a lien upon the property of
the Company or any Subsidiary; PROVIDED, HOWEVER, that the Company shall not
be required to pay or discharge or cause to be paid or discharged any such
tax, assessment, charge or claim whose amount, applicability or validity is
being contested in good faith by appropriate proceedings.

         SECTION 1008.  STATEMENT OF OFFICERS AS TO DEFAULT.

         The Company will deliver to the Trustee, within 120 days after the
end of each fiscal year (which on the date hereof ends on June 30) of the
Company ending after the date hereof, an Officers' Certificate, stating
whether or not to the best knowledge of the signers thereof the Company is in
default in the performance and observance of any of the terms, provisions and
conditions of this Indenture, and if the Company shall be in default,
specifying all such defaults and the nature and status thereof of which they
may have knowledge.

         SECTION 1009. WAIVER OF CERTAIN COVENANTS.

         The Company may omit in any particular instance to comply with any
term, provision or condition set forth in Sections 1005 to 1007, inclusive,
if before the time for such compliance the Holders of at least a majority in
principal amount of the Outstanding Securities (or such lesser amount as
shall have acted at a meeting pursuant to the provisions of this Indenture)
shall, by Act of such Holders, either waive such compliance in such instance
or generally waive compliance with such term, provision or condition, but no
such waiver shall extend to or affect such term, provision or condition
except to the extent so expressly waived, and, until such waiver shall become
effective, the obligations of the Company and the duties of the Trustee in
respect of any such term, provision or condition shall remain in full force
and effect.

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         SECTION 1010. WAIVER OF USURY LAWS.

         The Company shall not insist (to the extent that it may lawfully do
so) at any time upon, or plead, or in any manner whatsoever claim or take the
benefit or advantage of, any usury or similar law which would prohibit or
forgive the Company from paying all or any portion of the interest on the
Securities as contemplated herein, wherever enacted, now or at any time
hereafter in force.

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                               ARTICLE ELEVEN

                          Redemption of Securities

         SECTION 1101. RIGHT OF REDEMPTION.

         The Securities may be redeemed subject to the conditions, at the
times and at the Redemption Prices specified in the forms of Securities set
forth in Section 202, together with accrued interest to the Redemption Date;
PROVIDED, HOWEVER, that until the ninetieth day after the Exchange Date, the
Company may not redeem the Securities other than under the circumstances
described in the third paragraph on the reverse side of such forms (involving
United States taxes) or in the fourth paragraph on the reverse side of such
forms (involving certification requirements).

         SECTION 1102. APPLICABILITY OF ARTICLE.

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

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

         SECTION 1103. ELECTION TO REDEEM; NOTICE TO TRUSTEE

         The election of the Company to redeem any Securities shall be
evidenced by a Board Resolution. In case of any redemption of all of the
Securities, the Company shall, at least 60 days prior to the Redemption Date
fixed by the Company (unless a shorter notice shall be satisfactory to the
Trustee and the Principal Paying Agent), notify the Trustee and the Principal
Paying Agent of such Redemption Date. In case of any redemption of less than
all the Securities, the Company shall, at least 75 days prior to the
Redemption Date fixed by the Company (unless a shorter notice shall be
satisfactory to the Trustee and the Principal Paying Agent), notify the
Trustee and the Principal Paying Agent of such Redemption Date and of the
principal amount of Securities to be redeemed. If

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the Securities are to be redeemed pursuant to an election of the Company
which is subject to a condition specified in the forms of Securities set
forth in Section 202, the Company shall furnish the Trustee and the Principal
Paying Agent with (i) an Officers' Certificate stating that the Company is
entitled to effect such redemption and setting forth a statement of facts
showing that the conditions precedent to the right of the Company to so
redeem have occurred and (ii) with respect to a redemption as a result of
the circumstances described in the third paragraph on the reverse of the form
of Securities set forth in Section 202, an opinion of independent counsel
(who shall be reasonably satisfactory to the Trustee) to such effect based on
such statement of facts.

         SECTION 1104.  SELECTION BY TRUSTEE OF SECURITIES TO BE REDEEMED.

         If less than all the Securities are to be redeemed, the particular
Securities to be so redeemed shall be selected not more than 60 days prior to
the Redemption Date by the Principal Paying Agent, from the Outstanding
Securities not previously called for redemption, by such method as the
Trustee shall deem fair and equitable and which may provide for the selection
for redemption of portions (equal to U.S. $5,000 or any integral multiple
thereof) of the principal amount of Registered Securities of a denomination
larger than U.S. $5,000. Partial redemptions of Securities at the option of
the Company may only be made in aggregate principal amounts of not less than
U.S. $1,000,000.

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

         The Principal Paying Agent shall promptly notify the Company, the
Trustee and each Security Registrar in writing of the Securities selected for
redemption and, in the case of any Registered Securities selected for
partial redemption, the principal amount thereof to be redeemed.

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         SECTION 1105. NOTICE OF REDEMPTION.

         Notice of redemption shall be given in the manner provided in
Section 105 to the Holders of Securities to be redeemed. If all of the
Outstanding Securities are to be so redeemed, notice shall be given once not
less than 30 nor more than 60 days prior to the Redemption Date. If less than
all the Outstanding Securities are to be so redeemed, notice shall be given
twice, the first such notice to be given not more than 75 nor less than 60
days prior to the Redemption Date and the second notice to be given at least
20 days after the first such notice but not less than 30 days prior to the
Redemption Date.

         All notices of redemption shall state:

         (1) the Redemption Date,

         (2) the Redemption Price,

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

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

         (5) the Conversion Price, the date on which the right to convert the
    principal of the Securities to be redeemed will terminate and the place
    or places where such Securities may be surrendered for conversion, and

         (6) the place or places where such Securities, together in the case
    of Bearer Securities with all coupons appertaining thereto, if any,
    maturing after the Redemption Date, are to be surrendered for payment of
    the Redemption Price.

         In case of a partial redemption, the first notice given shall
specify the last date on which exchanges or transfers of Securities may be
made pursuant to Section 305, and the second notice shall specify the serial
numbers of the Bearer Securities called for redemption and, in the case of
Registered Securities, the serial numbers and the portions thereof called for
redemption.

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         Notice of redemption of Securities to be redeemed shall be given by
the Company or, at the Company's request, by the Principal Paying Agent in
the name of and at the expense of the Company.

         SECTION 1106. DEPOSIT OF REDEMPTION PRICE.

         On or prior to any Redemption Date, the Company shall deposit with
the Principal Paying Agent (or, if the Company is acting as its own Paying
Agent, segregate and hold in trust as provided in Section 1003) an amount of
money sufficient to pay the Redemption Price of, and (except if the
Redemption Date shall be an Interest Payment Date) accrued interest on, all
the Securities which are to be redeemed on that date other than any
Securities called or tendered for redemption on that date which have been
converted prior to the date of such deposit.

         If any Security called or tendered for redemption is converted, any
money deposited with the Principal Paying Agent or so segregated and held in
trust for the redemption of such Security shall (subject to any right of the
Holder of such Security or any Predecessor Security to receive interest as
provided in the last paragraph of Section 307) be paid to the Company upon
Company Request or, if then held by the Company, shall be discharged from
such trust.

         SECTION 1107. SECURITIES PAYABLE ON REDEMPTION DATE

         Notice of redemption having been given as aforesaid, the Securities
so to be redeemed shall, on the Redemption Date, become due and payable at
the Redemption Price therein specified, and from and after such date (unless
the Company shall default in the payment of the Redemption Price and accrued
interest) such Securities shall cease to bear interest and the coupons for
such interest appertaining to Bearer Securities shall, except to the extent
provided below, be void. Upon surrender of any such Security for redemption
in accordance with said notice, together with all coupons, if any,
appertaining thereto maturing after the Redemption Date, such Security shall
be paid by the Company at the Redemption Price together with accrued interest
to the Redemption Date; PROVIDED, HOWEVER, that installments of interest on
Bearer Securities whose Stated Maturity is on or prior to the Redemption Date
shall be payable only upon presentation and surrender of coupons for such
interest (at an office or agency outside the United States except as
otherwise provided in the forms of

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Security set forth in Section 202); and PROVIDED, FURTHER, that installments
of interest on Registered Securities whose Stated Maturity is on or prior to
the Redemption Date shall be payable to the Holders of such Securities, or
one or more Predecessor Securities, registered as such at the close of
business on the relevant Record Date according to their terms and the
provisions of Section 307.

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

         If any Bearer Security surrendered for redemption shall not be
accompanied by all appurtenant coupons maturing after the Redemption Date,
such Security may be paid after deducting from the Redemption Price an amount
equal to the face amount of all such missing coupons or the surrender of such
missing coupon or coupons may be waived by the Company and the Trustee or the
Principal Paying Agent, if there be furnished to them such security or
indemnity as they may require to save each of them and any Paying Agent
harmless. If thereafter the Holder of such Security shall surrender to any
Paying Agent any such missing coupon in respect of which a deduction shall
have been made from the Redemption Price, such Holder shall be entitled to
receive the amount so deducted; PROVIDED, HOWEVER, that interest represented
by coupons shall be payable only upon presentation and surrender of those
coupons at an office or agency located outside of the United States (except
as otherwise provided in the forms of Security set forth in Section 202).

         SECTION 1108. REGISTERED SECURITIES REDEEMED IN PART.

         Any Registered Security which is to be redeemed only in part shall
be surrendered at an office or agency of the Company designated for that
purpose pursuant to Section 1002 (with, if the Company or the Trustee or the
Principal Paying Agent so requires, due endorsement by, or a written
instrument of transfer in form satisfactory to the Company and the Trustee
and the Principal Paying Agent duly executed by, the Holder thereof or his
attorney duly authorized in writing), and the Company shall execute, and the
Trustee shall authenticate and deliver to the Holder of such Registered
Security without service charge, a new Registered Security or Securities, of
any authorized

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denomination as requested by such Holder, in aggregate principal amount equal
to and in exchange for the unredeemed portion of the principal of the
Registered Security so surrendered.

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<PAGE>

                               ARTICLE TWELVE

                          Conversion of Securities

         SECTION 1201. CONVERSION PRIVILEGE AND CONVERSION PRICE.

         Subject to and upon compliance with the provisions of this Article,
at the option of the Holder thereof, any definitive Security or, in the case
of any Registered Security, any portion of the principal amount thereof which
is U.S. $5,000 or an integral multiple of U.S. $5,000 may be converted at the
principal amount thereof, or of such portion thereof, into fully paid and
nonassessable shares (calculated as to each conversion to the nearest 1/100
of a share) of Common Stock, at the Conversion Price, determined as
hereinafter provided, in effect at the time of conversion. Such conversion
right shall commence at the opening of business on the Exchange Date and
expire at the close of business on May 21, 2002. In case a Security or
portion thereof is called for redemption, such conversion right in respect of
the Security or portion so called shall expire at the close of business on
the date five business days next preceding the Redemption Date, unless the
Company defaults in making the payment due upon redemption.

         The price at which shares of Common Stock shall be delivered upon
conversion (herein called the "Conversion Price") shall be initially U.S.
$37.00 per share of Common Stock. The Conversion Price shall be adjusted in
certain instances as provided in paragraphs (1), (2), (3) and (5) of Section
1204.

         SECTION 1202. EXERCISE OF CONVERSION PRIVILEGE.

         In order to exercise the conversion privilege, the Holder of any
definitive Security to be converted shall surrender such Security, together
in the case of Bearer Securities with all unmatured coupons and any matured
coupons in default appertaining thereto, duly endorsed or assigned to the
Company or in blank, at any office or agency of the Company maintained for
that purpose pursuant to Section 1002, accompanied by written notice to the
Company at such office or agency that the Holder elects to convert such
Security or, in the case of Registered Securities, if less than the entire
principal amount thereof is to be converted, the portion thereof to be
converted that is U.S. $5,000 or an integral multiple of

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<PAGE>

U.S. $5,000. Registered Securities surrendered for conversion during the
period from the close of business on any Regular Record Date next preceding
any Interest Payment Date to the opening of business on such Interest Payment
Date shall (except in the case of Registered Securities or portions thereof
which have been called for redemption on a Redemption Date within such
period) be accompanied by payment in funds reasonably acceptable to the
Company of an amount equal to the interest payable on such Interest Payment
Date on the principal amount of Registered Securities being surrendered for
conversion (or, if such Registered Security was issued in exchange for a
Bearer Security after the close of business on such Regular Record Date, by
surrender of one or more coupons relating to such Interest Payment Date or by
both payment in such funds and surrender of such coupon or coupons, in either
case, in an amount equal to the interest payable on such Interest Payment
Date on the principal amount of the Registered Security then being
converted). Except as provided in the preceding sentence and subject to the
last paragraph of Section 307, no payment or adjustment shall be made upon
any conversion on account of any interest accrued on the Securities
surrendered for conversion or on account of any dividends on the Common Stock
issued upon conversion.

         Securities shall be deemed to have been converted immediately prior
to the close of business on the day of surrender of such Securities for
conversion in accordance with the foregoing provisions, and at such time the
rights of the Holders of such Securities as Holders shall cease, and the
Person or Persons entitled to receive the Common Stock issuable upon
conversion shall be treated for all purposes as the record holder or holders
of such Common Stock at such time. As promptly as practicable on or after the
conversion date, the Company shall issue and shall deliver at such office or
agency a certificate or certificates for the number of full shares of Common
Stock issuable upon conversion, together with payment in lieu of any fraction
of a share, as provided in Section 1203.

         In the case of any Registered Security which is converted in part
only, upon such conversion the Company shall execute and the Trustee shall
authenticate and deliver to the Holder thereof, at the expense of the
Company, a new Registered Security or Registered Securities of authorized
denominations in aggregate principal amount equal to the unconverted portion
of the principal amount of such Registered Securities, which new Registered
Security or

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Securities shall bear the same legend or legends as the Registered Security
surrendered for conversion.

         SECTION 1203. FRACTIONS OF SHARES.

         No fractional shares or scrip representing fractional shares of
Common Stock shall be issued upon conversion of Securities. If more than one
Security shall be surrendered for conversion at one time by the same Holder,
the number of full shares which shall be issuable upon conversion thereof
shall be computed on the basis of the aggregate principal amount of the
Securities (or, in the case of Registered Securities, specified portions
thereof) so surrendered. Instead of any fractional share of Common Stock
which would otherwise be issuable upon the conversion of any Security or
Securities (or in the case of Registered Securities, specified portions
thereof), the Company shall pay a cash adjustment in respect of such fraction
in an amount equal to the current market value of such fractional interest
computed to the nearest cent on the basis of the Closing Market Price Per
Share of the Common Stock on the last day prior to the day of conversion on
which there is such a Closing Market Price Per Share.

         SECTION 1204. ADJUSTMENT OF CONVERSION PRICE.

         (1) In case at any time after May 5, 1987 the Company shall (i) pay
or make a dividend or other distribution on any class or series of capital
stock of the Company in shares of Common Stock, (ii) subdivide its
outstanding shares of Common Stock, (iii) combine its outstanding shares of
Common Stock into a smaller number of shares, (iv) issue by reclassification
of its Common Stock any shares of its capital stock, or (v) make a
distribution on its Common Stock in shares of its capital stock other than
Common Stock, the Conversion Price in effect immediately prior thereto shall
be adjusted so that the Holder of a Security thereafter converted may receive
the number of shares of Common Stock or capital stock of the Company which
he would have owned immediately following such action if he had converted
the Security immediately prior to such action. Such adjustment shall become
effective immediately at the opening of business on the day following the
record date, if any, in the case of a dividend, distribution, subdivision,
combination or reclassification with respect to which the Company has fixed a
record date for the determination of shareholders entitled to receive such
dividend, distribution, subdivision, combination or reclassification, or if
no such record date has been fixed, such reduction

                                      105

<PAGE>

shall become effective immediately after the opening of business on the day
following the effective date of such dividend, distribution, subdivision,
combination or reclassification. For the purposes of paragraph (1)(i), the
number of shares of Common Stock at any time outstanding shall not include
shares held in the treasury of the Company but shall include shares issuable
in respect of scrip certificates issued in lieu of fractions of shares of
Common Stock. The Company will not pay any dividend or make any distribution
on shares of Common Stock held in the treasury of the Company.

         (2) In case at any time after May 5, 1987 the Company shall issue
rights or warrants to all holders of its Common Stock entitling them
initially to subscribe for or purchase shares of Common Stock at a price per
share less than the current market price per share (determined as provided in
paragraph (4) of this Section 1204) of the Common Stock on the date fixed for
the determination of stockholders entitled to receive such rights or
warrants, the Conversion Price in effect at the opening of business on the
day following the date fixed for such determination shall be reduced by
multiplying such Conversion Price by a fraction of which the numerator shall
be the number of shares of Common Stock outstanding at the close of business
on the date fixed for such determination plus the number of shares of Common
Stock which the aggregate of the offering price of the total number of shares
of Common Stock so offered for subscription or purchase would purchase at
such current market price and the denominator shall be the number of shares
of Common Stock outstanding at the close of business on the date fixed for
such determination plus the number of shares of Common Stock so offered for
subscription or purchase, such reduction to be made whenever such rights or
warrants are issued and will become effective immediately at the opening of
business on the day following the date fixed for such determination. For the
purposes of this paragraph (2), the number of shares of Common Stock at any
time outstanding shall not include shares held in the treasury of the Company
but shall include shares issuable in respect of scrip certificates issued in
lieu of fractions of shares of Common Stock. The Company will not issue any
rights or warrants in respect of shares of Common Stock held in the treasury
of the Company.

         (3)  In case at any time after May 5, 1987 the Company shall, by
dividend or otherwise, distribute to all holders of its Common Stock
evidences of its indebtedness or any of its assets, or any rights or warrants
entitling

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<PAGE>

holders thereof to subscribe for or purchase securities of the Company or any
other securities (but excluding any rights or warrants referred to in
paragraph (2) of this Section 1204, any dividend or distribution paid in
cash, any dividend or distribution paid out of the surplus of the Company or
the consolidated net profits for the then current or preceding fiscal year of
the Company and any dividend or distribution referred to in paragraph (1) of
this Section), the Conversion Price shall be adjusted so that the same shall
equal the price determined by multiplying the Conversion Price in effect
immediately prior to such action by a fraction of which the numerator shall
be the current market price per share (determined as provided in paragraph
(4) of this Section) of the Common Stock on the date fixed for the
determination of stockholders entitled to receive such distribution less the
then fair market value (as determined by the Board of Directors, whose
determination shall be conclusive and described in a Board Resolution) of the
portion of such assets or evidences of indebtedness or shares or rights or
warrants so distributed applicable to one share of Common Stock and the
denominator shall be such current market price per share of the Common Stock,
such adjustment to be made whenever such distribution is made and shall
become effective immediately at the opening of business on the day following
the date fixed for the determination of stockholders entitled to receive such
distribution. In the event that the Company shall distribute or shall have
distributed to all holders of shares of Common Stock, rights or warrants to
purchase securities that are not initially detachable from the Common Stock
(whether or not such distribution shall have occurred prior to the date of
this Indenture), then the distribution of separate certificates representing
such rights or warrants subsequent to their initial distribution shall be
deemed to be the distribution of such rights or warrants for purposes of this
paragraph (3). Notwithstanding the foregoing, in the event that the Company
shall distribute rights or warrants to purchase securities ("Rights") to
holders of Common Stock, the Company may, in lieu of making the foregoing
adjustment pursuant to this paragraph (3) and to the extent such Rights would
be issued with other shares of Common Stock issued at the time of conversion,
make proper provision so that each Holder of a Security who converts such
Security (or any portion thereof) (a) before the record date for such
distribution shall be entitled to receive upon such conversion shares of
Common Stock issued with Rights and (b) after the record date for such
distribution (but prior to the expiration or redemption of the Rights) shall
be entitled to receive upon such conversion,

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in addition to the shares of Common Stock issuable upon such conversion, 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 record date for such distribution would
have been entitled on the record date for such distribution in accordance
with the terms and provisions of and applicable to the Rights.

          (4) For the purpose of any computation under paragraphs (2) and (3)
of this Section, the current market price per share of Common Stock in any
case shall be deemed to be the average of the Closing Market Prices Per Share
for 20 consecutive trading days selected by the Company during the period
commencing 30 trading days before the day in question.

          (5) No adjustment in the Conversion Price shall be required unless
such adjustment would require an increase or decrease of at least 1 per cent.
in the Conversion Price; PROVIDED, HOWEVER, that any adjustments which by
reason of this paragraph (5) are not required to be made shall be carried
forward and taken into account in any subsequent adjustment. All calculations
shall be made to the nearest cent or to the nearest one-hundredth of a share,
as the case may be.

          (6) No adjustment in the Conversion Price shall be required in the
case of transactions (i) in which the Holders of Securities are entitled to
participate on a basis and with notice that the Board of Directors determines
to be fair and appropriate or (ii) which effectuate a change in the par value
or lack thereof of the Common Stock.

          (7) The Company from time to time may reduce the Conversion Price
by any amount for any period of time, provided that the reduction is
effective for at least 20 days and that the reduction is irrevocable during
such period. Whenever the Conversion Price is reduced, the Company shall
publish notice of the reduction to Holders of Securities. The Company shall
publish such notice at least 15 days before the date the reduced Conversion
Price takes effect. The notice shall state the reduced Conversion Price and
the period it will be in effect. After the expiration of such period, the
Conversion Price shall revert to the price immediately preceding such
reduction. The Company may also, from time to time, reduce the Conversion
Price in order to avoid taxation of the Company's stockholders in connection
with the transactions described in this Section

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1204. The Company may, but is not required to, reduce the Conversion Price if
the making of, or a failure to make, an adjustment in the Conversion Price
under this Article would cause imposition of a tax on the Company's
stockholders.

         (8)  In any case in which this Section 1204 shall require that an
adjustment be made, the Company may elect to defer (but only until five
Business Days in the Place of Conversion following the effective date of such
adjustment) the issuance to the holder of any Securities converted after such
effective date of the shares of Common Stock or rights or warrants issuable
on such conversion in excess of or in addition to the shares of Common Stock
issuable on such conversion on the basis of the Conversion Price prior to
such adjustment.

         SECTION 1205. NOTICE OF ADJUSTMENTS OF CONVERSION PRICE.

         Whenever the Conversion Price is adjusted as herein provided:

         (a) the Company shall compute the adjusted Conversion Price in
    accordance with Section 1204 and shall prepare a certificate signed by
    the Treasurer of the Company setting forth the adjusted Conversion Price
    and showing in reasonable detail the facts upon which such adjustment is
    based, and such certificate shall forthwith be filed with the Trustee and
    at each office or agency maintained for the purpose of conversion of
    Securities pursuant to Section 1002; and

         (b)  a notice stating that the Conversion Price has been adjusted
    and setting forth in reasonable detail the facts upon which such
    adjustment is based the adjusted Conversion Price shall as soon as
    practicable after the effectiveness of such adjustment be mailed by the
    Company to all Registered Holders at their last addresses as they shall
    appear in the Security Register and shall be published (but only once) in
    accordance with Section 105.

         SECTION 1206. NOTICE OF CERTAIN CORPORATE ACTION.

         In case at any time after May 5, 1987:

         (a) the Company shall declare a dividend (or any other distribution)
    on its Common Stock payable

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    otherwise than in cash or out of its surplus or its consolidated net
    profits for its then current or preceding fiscal year; or

         (b) the Company shall authorize the granting to all holders of its
    Common Stock of rights or warrants to subscribe for or purchase Common
    Stock or of any other rights; or

         (c) there shall occur any reclassification of the Common Stock of
    the Company (other than a subdivision or combination of its outstanding
    shares of Common Stock), or any consolidation or merger to which the
    Company is a party and for which approval of any stockholders of the
    Company is required, or the sale or transfer of all or substantially all
    of the assets of the Company; or

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

then (unless the Company has filed and mailed a notice pursuant to Section
1205 with respect to the events described in this Section 1206) the Company
shall cause to be filed with the Trustee and at each office or agency
maintained for the purpose of conversion of Securities pursuant to Section
1002, and shall cause to be mailed to all Registered Holders at their last
addresses as they shall appear in the Security Register and shall publish
(but only once) in accordance with Section 105, in each case, at least 20
days (or 10 days in any case specified in clause (a) or (b) above) prior to
the applicable record date hereinafter specified, a notice stating (x) the
date on which a record is to be taken for the purpose of such dividend,
distribution, rights or warrants, or, if a record is not to be taken, the
date as of which the holders of Common Stock of record to be entitled to
such dividend, distribution, rights or warrants are to be determined, or (y)
the date on which such reclassification, consolidation, merger, sale,
transfer, dissolution, liquidation or winding up is expected to become
effective, and the date as of which it is expected that holders of Common
Stock of record shall be entitled to exchange their shares of Common Stock
for securities, cash or other property deliverable upon such
reclassification, consolidation, merger, sale, transfer, dissolution,
liquidation or winding up. Failure to give any such notice, or any defect
therein, shall not

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affect the validity of the proceedings referred to in clauses (a), (b), (c)
or (d) above.

         SECTION 1207. COMPANY TO RESERVE COMMON STOCK.

         The Company shall at all times reserve and keep available, free from
pre-emptive rights, out of its authorized but unissued Common Stock, for the
purpose of effecting the conversion of Securities, the full number of shares
of Common Stock then issuable upon the conversion of all Outstanding
Securities.

         The Company shall promptly after the issuance of the Global Security
endeavor (i) to cause all registrations with, and to obtain any approval by,
any governmental authority under any Federal or state law of the United
States that may be required before the shares of Common Stock may be lawfully
issued or transferred and delivered pursuant to this Article and (ii) to list
or arrange for the quotation of the shares of Common Stock required to be
issued or delivered upon conversion of Securities prior to such issue or
delivery on each national securities exchange or quotation system on which
the outstanding Common Stock is listed or quoted at the time of such delivery.

         SECTION 1208. TAXES ON CONVERSIONS.

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

         SECTION 1209. COVENANT AS TO COMMON STOCK.

         The Company covenants that all shares of Common Stock which may be
issued upon conversion of Securities will upon issue be fully paid and
nonassessable and, except as provided in Section 1208, the Company will pay
all taxes or duties, liens and charges with respect to the issue thereof.

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         SECTION 1210. CANCELLATION OF CONVERTED SECURITIES.

         All Securities delivered for conversion shall be delivered to the
Principal Paying Agent to be cancelled by or at the direction of the
Principal Paying Agent, which shall dispose of the same as provided in
Section 309.

         SECTION 1211.  PROVISIONS IN CASE OF CONSOLIDATION, MERGER, SALE OF
                        ASSETS OR RECLASSIFICATION.

        (a) In case of any consolidation of the Company with, or merger of
the Company into, any other corporation (other than a merger or consolidation
in which the Company is the continuing corporation), or in case of any sale
or transfer of all or substantially all of the properties and assets of the
Company as an entirety, the corporation formed by such consolidation or
resulting from such merger or which acquires such assets, as the case may be,
shall execute and deliver to the Trustee a supplemental indenture providing
that the Holder of each Security then outstanding shall have the right
thereafter, during the period such Security shall be convertible as specified
in Section 1201, to convert such Security, in lieu of conversion into the
shares of Common Stock deliverable on conversion immediately prior to such
event, only into the kind and amount of securities and/or cash and/or other
property, if any, receivable upon such consolidation, merger, sale or
transfer by a holder of the number of shares of Common Stock into which such
Security might have been converted immediately prior to such consolidation,
merger, sale or transfer, assuming, if such consolidation, merger, sale or
transfer is prior to the Exchange Date, that the Securities were convertible
at the time of such consolidation, merger, sale or transfer at the initial
Conversion Price specified in Section 1201 as adjusted from May 5, 1987 to
such time pursuant to Section 1204.

         (b) In case of any reclassification or change of the shares of
Common Stock (other than a change in par value, or from par value to no par
value, or as a result of a subdivision or combination) or in case of any
consolidation or merger of another corporation into the Company in which the
Company is the continuing corporation and in which the holders of the shares
of Common Stock thereafter receive securities and/or cash and/or other
property for such shares of Common Stock (including for this purpose shares
reflecting a change in par value or from par value to no

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par value or as a result of a subdivision or combination of the shares of
Common Stock), the Company (and any issuer of securities and/or cash and/or
property exchanged for Common Stock) shall execute and deliver to the Trustee
a supplemental indenture providing that the Holder of each Security then
outstanding shall have the right thereafter, during the period such Security
shall be convertible as specified in Section 1201, to convert such Security,
in lieu of conversion into the shares of Common Stock deliverable on such
conversion immediately prior to such event, only into the kind and amount of
securities and/or cash and/or other property, if any, receivable upon such
reclassification, change, consolidation or merger by a holder of the number of
shares of Common Stock into which such Security might have been converted
immediately prior to such reclassification, change, consolidation or merger,
assuming, if such reclassification, change, consolidation or merger is prior
to the Exchange Date, that the Securities were convertible at the time of
such reclassification, change, consolidation or merger at the initial
Conversion Price specified in Section 1201 as adjusted from May __, 1987 to
such time pursuant to Section 1204. If, as a result of this subsection (b),
the holder of any Securities thereafter surrendered for conversion shall
become entitled to receive shares of two or more classes of capital stock of
the Company, the Board of Directors (whose determination shall be conclusive
and shall be described in a Board Resolution) shall determine the allocation
of the Conversion Price between or among shares of such classes of capital
stock.

     (c) Supplemental indentures referred to in subsections (a) and (b) above
shall provide for adjustments which shall be as nearly equivalent as may be
practicable to the adjustments provided for in this Article. The above
provisions of this Section shall similarly apply to successive
consolidations, mergers, sales, transfers, reclassifications or changes.

     SECTION 1212.  RESPONSIBILITY OF TRUSTEE FOR CONVERSION PROVISIONS.

     The Trustee, subject to the provisions of Section 601, and any
Conversion Agent shall not at any time be under any duty or responsibility to
any Holder to determine whether any facts exist which may require any
adjustment of the Conversion Price, or with respect to the nature or extent
of any such adjustment when made, or with respect to the method employed, or
herein or in any supplemental indenture provided to be employed, in making
the same.


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Neither the Trustee, subject to the provisions of Section 601, nor any
Conversion Agent shall be accountable with respect to the validity or value (or
the kind or amount) of any shares of Common Stock, or of any other securities or
property, which may at any time be issued or delivered upon the conversion of
any Security; and it or they do not make any representation with respect
thereto. Neither the Trustee, subject to the provisions of Section 601, nor any
Conversion Agent shall be responsible for any failure of the Company to make any
cash payment or to issue, transfer or deliver any shares of stock or stock
Certificates or other securities or property upon the surrender of any Security
for the purpose of conversion; and the Trustee, subject to the provisions of
Section 601, and any Conversion Agent shall not be responsible for any failure
of the Company to comply with any of the covenants of the Company contained in
this Article.



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                              ARTICLE THIRTEEN

                         Subordination of Securities

     SECTION 1301. SECURITIES SUBORDINATE TO SENIOR DEBT.

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

     SECTION 1302.  PAYMENT OVER OF PROCEEDS UPON DISSOLUTION, ETC.

     In the event of (a) any insolvency or bankruptcy case or proceeding, or
any receivership, liquidation, reorganization or other similar case or
proceeding in connection therewith, relative to the Company or to its
creditors, as such, or to its assets, or (b) any liquidation, dissolution or
other winding up of the Company, whether voluntary or involuntary and whether
or not involving insolvency or bankruptcy, or (c) any assignment for the
benefit of creditors or any other marshalling of assets and liabilities of
the Company, then and in any such event the holders of Senior Debt shall be
entitled to receive payment in full of all amounts due on or in respect of
all Senior Debt, or provision shall be made for such payment in money or
money's worth, before the Holders of the Securities or the coupons
appertaining thereto or the Trustee shall be entitled to receive any payment
on account of principal of (or premium, if any) or interest on the Securities
and the coupons appertaining thereto or of this Indenture, and to that end
the holders of Senior Debt shall be entitled to receive, for application to
the payment thereof, any payment or distribution of any kind or character,
whether in cash, property or securities which may be payable or deliverable
in respect of the Securities, the coupons appertaining thereto or of this
Indenture in any such case, proceeding, dissolution, liquidation or other
winding up or event.



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     In the event that, notwithstanding the foregoing provisions of this
Section, the Trustee or the Holder of any Security or any coupon appertaining
thereto shall have received any payment or distribution of assets of the
Company of any kind or character, whether in cash, property or securities,
before all Senior Debt is paid in full or payment thereof provided for, and
if such fact shall, at or prior to the time of such payment or distribution,
have been made known to the Trustee or, as the case may be, such Holder, then
and in such event such payment or distribution shall be paid over or
delivered forthwith to the trustee in bankruptcy, receiver, liquidating
trustee, custodian, assignee, agent or other Person making payment or
distribution of assets of the Company for application to the payment of all
Senior Debt remaining unpaid, to the extent necessary to pay all Senior Debt
in full, after giving effect to any concurrent payment or distribution to or
for the holders of Senior Debt.

     The consolidation of the Company with, or the merger of the Company
into, another corporation or the liquidation or dissolution of the Company
following the conveyance or transfer of its properties and assets
substantially as an entirety to another corporation upon the terms and
conditions set forth in Article Seven shall not be deemed a dissolution,
winding up, liquidation, reorganization, assignment for the benefit of
creditors or marshalling of assets and liabilities of the Company for the
purposes of this Section if the corporation formed by such consolidation or
into which the Company is merged or which acquires by conveyance or transfer
such properties and assets substantially as an entirety, as the case may be,
shall, as a part of such consolidation, merger, conveyance or transfer,
comply with the conditions set forth in Article Seven.

     SECTION 1303. PRIOR PAYMENT TO SENIOR DEBT UPON ACCELERATION OF
                   SECURITIES.

     In the event that any Securities are declared due and payable before
their Stated Maturity, then and in such event the holders of Senior Debt
shall be entitled to receive payment in full of amounts due on or in respect
of all Senior Debt, or provision shall be made for such payment in money or
money's worth, before the Holders of the Securities or coupon appertaining
thereto are entitled to receive any payment by the Company on account of the
principal of (or premium, if any) or interest on the

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Securities or such coupons or on account of the purchase or other acquisition
of Securities or such coupons.

     In the event that, notwithstanding the foregoing, the Company shall make
any payment to the Trustee or the Holder of any Security or any coupon
appertaining thereto prohibited by the foregoing provision of this Section,
and if such fact shall, at or prior to the time of such payment, have been
made known to the Trustee or, as the case may be, such Holder, then and in
such event such payment shall be paid over and delivered forthwith to the
Company.

     The provisions of this Section will not apply to any payment with
respect to which Section 1302 would be applicable.

     SECTION 1304.  NO PAYMENT WHEN SENIOR DEBT IN DEFAULT.

     (a) In the event and during the continuation of any default in the
payment of principal of (or premium, if any) or interest on any Senior Debt
beyond any applicable grace period with respect thereto, or in the event that
any event of default with respect to any Senior Debt shall have occurred and
be continuing permitting the holders of such Senior Debt (or a trustee on
behalf of the holders thereof) to declare such Senior Debt due and payable
prior to the date on which it would otherwise have become due and payable,
unless and until such event of default shall have been cured or waived or
shall have ceased to exist and any acceleration based thereon shall have been
rescinded or annulled, then no payment shall be made by the Company on
account of principal of (or premium, if any) or interest on the Securities or
the coupons appertaining thereto or on account of the purchase or other
acquisition of Securities. In the event that, notwithstanding the foregoing,
the Company shall make any payment to the Trustee or the Holder of any
Security or any coupon appertaining thereto prohibited by the foregoing
provisions of this Section, and if such fact shall then have been made known
to the Trustee or, as the case may be, such Holder, then and in such event
such payment shall be paid over and delivered forthwith to the Company.

     (b) In the event any judicial proceeding shall be pending with respect
to any default in payment or event of default described in sub-paragraph (a)
above, then the Company may elect not to make any payment on account of
principal of (or premium, if any) or interest on the



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Securities or the coupons appertaining thereto or on account of the purchase
or other acquisition of Securities; provided, however, that no such payment
shall be made if such payment would prejudice the rights of the holders of
Senior Debt.

     The provisions of this Section shall not apply to any payment with
respect to which Section 1302 would be applicable.

     SECTION 1305. PAYMENT PERMITTED IF NO DEFAULT.

     Nothing contained in this Article or elsewhere in this Indenture or in
any of the Securities shall prevent (a) the Company, at any time except
during the pendency of any case, proceedings, dissolution, liquidation or
other winding up, assignment for the benefit of creditors or other
marshalling of assets and liabilities of the Company referred to in Section
1302 or under the conditions described in Section 1303 or 1304, from making
payments at any time of principal of (and premium, if any) or interest on the
Securities or coupons appertaining thereto, or (b) the application by the
Trustee or any Paying Agent of any money deposited with it hereunder to the
payment of or on account of the principal of (and premium, if any) or
interest on the Securities or coupons appertaining thereto or the retention
of such payment by the Holders of the Securities or coupons appertaining
thereto, if, one day prior to the time of such application by the Trustee or
such Paying Agent, the Trustee or such Paying Agent did not have knowledge
that such payment would have been prohibited by the provisions of this
Article.

     SECTION 1306. SUBROGATION TO RIGHTS OF HOLDERS OF SENIOR DEBT.

     Subject to the payment in full of all Senior Debt, the Holders of the
Securities shall be subrogated to the extent of the payments or distributions
made to the Holders of such Senior Debt pursuant to the provisions of this
Article (equally and ratably with the holders of all "indebtedness of the
Company which by its express terms is subordinated to indebtedness of the
Company to substantially the same extent as the Securities are subordinated
and is entitled to like rights of subrogation, all such subordinated
indebtedness being hereinafter referred to as "PARI PASSU indebtedness") to
the rights of the holders of such Senior Debt to receive payments and
distributions of cash, property and securities applicable to the Senior Debt
until


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<PAGE>

the principal of (and premium, if any) and interest on the Securities shall
be paid in full. For purposes of such subrogation, no payments or
distributions to the holders of the Senior Debt of any cash, property or
securities to which the Holders of the Securities or the coupons appertaining
thereto or of PARI PASSU indebtedness or the Trustee or the trustee with
respect to PARI PASSU indebtedness would be entitled except for the
provisions of this Article or similar provisions applicable to PARI PASSU
indebtedness, as the case may be, and no payments over pursuant to the
provisions of this Article or similar provisions applicable to PARI PASSU
indebtedness, as the case may be, to the holders of Senior Debt by Holders of
the Securities or the coupons appertaining thereto or of PARI PASSU
indebtedness or the Trustee or the trustee with respect to PARI PASSU
indebtedness, shall, as among the Company, its creditors other than holders
of Senior Debt, and the Holders of the Securities and the coupons
appertaining thereto or of PARI PASSU indebtedness, be deemed to be a payment or
distribution by the Company to or on account of the Senior Debt.

     SECTION 1307. PROVISIONS SOLELY TO DEFINE RELATIVE RIGHTS.

     The provisions of this Article are and are intended solely for the
purpose of defining the relative rights of the Holders of the Securities and
the coupons appertaining thereto and the holders of PARI PASSU indebtedness,
on the one hand, and the holders of Senior Debt, on the other hand. Nothing
contained in this Article or elsewhere in this Indenture or in the Securities
is intended to or shall (a) impair, as among the Company, its creditors other
than holders of Senior Debt and the Holders of the Securities and the coupons
appertaining thereto, the obligation of the Company, which is absolute and
unconditional, to pay to the Holders of the Securities and the coupons
appertaining thereto the principal of (and premium, if any) and interest on
the Securities and the coupons appertaining thereto as and when the same
shall become due and payable in accordance with their terms; or (b) affect
the relative rights against the Company of the Holders of the Securities and
the coupons appertaining thereto and creditors of the Company other than the
holders of Senior Debt; or (c) prevent the Trustee or the Holder of any
Security or coupon appertaining thereto from exercising all remedies
otherwise permitted by applicable law upon default under this Indenture,
subject to the rights, if any, under this Article of the holders of Senior
Debt to receive cash,

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property and securities otherwise payable or deliverable to the Trustee or
such Holder.

     SECTION 1308. TRUSTEE TO EFFECTUATE SUBORDINATION.

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

     SECTION 1309. NO WAIVER OF SUBORDINATION PROVISIONS.

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

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

     SECTION 1310. NOTICE TO TRUSTEE.

     The Company shall give prompt written notice to the Trustee of any fact
known to the Company which would

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prohibit the making of any payment to or by the Trustee in respect of the
Securities or the coupons appertaining thereto. Notwithstanding the
provisions of this Article or any other provision of this Indenture, the
Trustee shall not be charged with knowledge of the existence of any facts
which would prohibit the making of any payment to or by the Trustee in
respect of the Securities or the coupons appertaining thereto, unless and
until the Trustee shall have received written notice thereof from the Company
or a holder of Senior Debt or from any trustee therefor; and, prior to the
receipt of any such written notice, the Trustee, subject to the provisions of
Section 601, shall be entitled in all respects to assume that no such facts
exist.

     Subject to the provisions of Section 601, the Trustee shall be entitled
to rely on the delivery to it of a written notice by a Person representing
himself to be a holder of Senior Debt (or a trustee therefor) to establish
that such notice has been given by a holder of Senior Debt (or a trustee
therefor). In the event that the Trustee determines in good faith that
further evidence is required with respect to the right of any person as a
holder of Senior Debt to participate in any payment or distribution pursuant
to this Article, the Trustee may request such Person to furnish evidence to
the reasonable satisfaction of the Trustee as to the amount of Senior Debt
held by such Person, the extent to which such Person is entitled to
participate in such payment or distribution and any other facts pertinent to
the rights of such Person under this Article, and if such evidence is not
furnished, the Trustee may defer any payment to such Person pending judicial
determination as to the right of such Person to receive such payment.

     SECTION 1311. RELIANCE ON JUDICIAL ORDER OR CERTIFICATE OF LIQUIDATING
                   AGENT.

     Upon any payment or distribution of assets of the Company referred to in
this Article, the Trustee, subject to the provisions of Section 601, and the
Holders of the Securities and coupons appertaining thereto shall be entitled
to rely upon any order or decree entered by any court of competent
jurisdiction in which such insolvency, bankruptcy, receivership, liquidation,
reorganization, dissolution, winding up or similar case or proceeding is
pending, or a certificate of the trustee in bankruptcy, liquidating trustee,
custodian, receiver, assignee for the benefit of creditors, agent or other

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Person making such payment or distribution, delivered to the Trustee or to
such Holders, for the purpose of ascertaining the Persons entitled to
participate in such payment or distribution, the holders of the Senior Debt
and other indebtedness of the Company, the amount thereof or payable thereon,
the amount or amounts paid or distributed thereon and all other facts
pertinent thereto or to this Article.

     SECTION 1312. TRUSTEE NOT FIDUCIARY FOR HOLDERS OF SENIOR DEBT.

     The Trustee shall not be deemed to owe any fiduciary duty to the holders
of Senior Debt and shall not be liable to any such holders if it shall in
good faith mistakenly pay over or distribute to Holders of Securities or the
coupons appertaining thereto or to the Company or to any other Person cash,
property or securities to which any holders of Senior Debt shall be entitled
by virtue of this Article or otherwise.

     SECTION 1313.  RIGHTS OF TRUSTEE AS HOLDER OF SENIOR DEBT; PRESERVATION OF
                    TRUSTEE'S RIGHTS.

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

     Nothing in this Article shall apply to claims of, or payments to, the
Trustee under or pursuant to Section 606.

     SECTION 1314. ARTICLE APPLICABLE TO PAYING AGENTS.

     The term "Trustee" as used in this Article shall (unless the context
otherwise requires) be construed as extending to and including each Paying
Agent within its meaning as fully for all intents and purposes as if such
Paying Agent were named in this Article in addition to or in place of the
Trustee; PROVIDED, HOWEVER, that Section 1313 shall not apply to the Company
or any Affiliate of the Company if it or such Affiliate acts as Paying Agent.

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



                                       122

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed, and their respective corporate seals to be hereunto affixed
and attested, all as of the day and year first above written.

                                       CETUS CORPORATION

                                       By /s/ Hollings C. Renton
                                          -----------------------------------
Attest:

/s/ Michael S. Ostrach
------------------------------------
Asst Secretary

                                       BANKERS TRUST COMPANY, as Trustee

                                       By /s/ Michael Ravensbergen
                                          -----------------------------------
                                          Authorized Officer

Attest:

/s/ S. Ward
------------------------------------
Authorized Officer



                                     123

<PAGE>

                                   EXHIBIT A

                [Form of certificate to be given by Euro-clear and
                                  CEDEL S.A.]

                                  CERTIFICATE

                               CETUS CORPORATION

          5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES DUE 2002

     This is to certify with respect to U.S. $_________ principal amount of the
above-captioned Securities (i) that we have received a certificate in writing
or tested telex with respect to each of the persons appearing in our records
as persons entitled to a portion of such principal amount (our "Qualified
Account Holders") either (a) from such Qualified Account Holder,
substantially in the form of Exhibit B to the Indenture dated as of May 21,
1987 (the "Indenture") in respect of such Securities or (b) from Swiss Bank
Corporation International Limited, substantially in the form of Exhibit D to
the Indenture, and (ii) that we are not submitting herewith for exchange any
portion of the Global Security representing the above-captioned Securities
excepted in such certificates.

     We further certify that as of the date hereof we have not received any
notification from any of our Qualified Account Holders or Swiss Bank
Corporation International Limited to the effect that the statements made by
such Qualified Account Holders or Swiss Bank Corporation International
Limited, as the case may be, with respect to any portion of the part
submitted herewith for exchange are no longer true and cannot be relied upon
as of the date hereof.

     We understand that this certificate is required in connection with
certain securities and tax legislation in the United States. If
administrative or legal proceedings are commenced or threatened in connection
with which this certificate is or would be relevant, we irrevocably authorize
you to produce this certificate or a copy thereof to any interested party in
such proceedings.

     Dated:          , 19  *



                                        [MORGAN GUARANTY TRUST COMPANY OF NEW
                                        YORK, BRUSSELS OFFICE, AS OPERATOR OF
                                        THE EURO-CLEAR CLEARANCE SYSTEM]
                                        [CEDEL S.A.]

                                        By
                                          ------------------------------

---------------
*    To be dated no earlier than the Exchange Date, except in the case of an
     exchange with respect to which the clearance system has received a
     certificate referred to in clause (i)(b) of the first paragraph hereof.

<PAGE>

                                   EXHIBIT B

                  [Form of certificate to be given by Qualified
                                Account Holders]

                                  CERTIFICATE

                               CETUS CORPORATION

       5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES DUE 2002

     This is to certify that as of the date hereof (a) except as provided in
(b) below, no part of the interest in the U.S. $[         ] of the
above-described Securities appearing in your books as held for our account is
being acquired by or on behalf of a citizen or resident of the United States
of America (including the States and the District of Columbia), its
territories, its possessions and other areas subject to its jurisdiction
("United States") or a corporation, partnership or other entity created or
organized in or under the laws of the United States or any State thereof or
an estate or trust the income of which is subject to United States federal
income taxation regardless of its source (a "U.S. person") or a person who
has purchased such Securities for offer to resell or for resale to a U.S.
person or to any person in the United States, and (b) U.S. $[         ] of
such Notes appearing in your books as held for our account are beneficially
owned by branches of United States banks located outside the United States
which have signed and furnished to us a letter substantially in the form of
Exhibit C to the Indenture dated as of May 21, 1987 in respect of such
Securities.

     We undertake to advise you by telex if the above statement as to
beneficial ownership is not correct on [THE EXCHANGE DATE] as to all of the
above-captioned Securities then appearing in your books as being held for our
account.

     We understand that this certificate is required in connection with
certain securities and tax legislation in the United States. If
administrative or legal proceedings are commenced or threatened in connection
with which this certificate is or would be relevant, we irrevocably authorize
you to produce this certificate or a copy thereof to any interested party in
such proceedings.

                                        --------------------------------------
                                                   Account Holder

Dated                            *



--------------------
*     To be dated on or after the 15th day before the Exchange Date.

<PAGE>

                                   EXHIBIT C

              [Form of Investment Letter for U.S. Bank Branch]

                       [Letterhead of U.S. Bank Branch]

[Address of Account-Holder]



     Purchase of U.S. $_____________* principal amount of Cetus
     Corporation (the "Company") 5 1/4 per cent. Convertible
     Subordinated Debentures due 2002 (the "Securities")
     -----------------------------------------------------------

                                                                         [Date]

Dear Sirs,

     In connection with our purchase of Securities we confirm that:

     1.   We are a branch located outside the United States of a bank
organized under federal or state law in the United States, we are a financial
institution as defined in United States Treasury regulation section 1.165-12
(c)(1)(v) we agree to comply with the requirements of section 165(j)(3)(A),
(B) or (C) of the United States Internal Revenue Code of 1986 and the
regulations thereunder, we are not purchasing the Securities for offer to
resell or for resale in the United States and, as a condition of our purchase
of the Securities, we agree to provide or cause to be provided on delivery of
the Securities in definitive form certificates substantially in the form of
Exhibits A and B to the Indenture relating to the Securities and to furnish a
copy of this letter to any person that will provide the certificate in the
form of Exhibit B to the Indenture.

------------
*    Not less than U.S. $500,000 minimum principal amount.

<PAGE>
                                     C-2

     2.   We understand that the Securities are not being, and that the
shares of common stock (the "Common Stock") of the Company into which the
Securities are convertible (the "Conversion Shares") may not be, registered
under the United States Securities Act of 1933 (the "1933 Act") and are being
sold to us in a transaction that is exempt from the registration requirements
of the 1933 Act.

     3.   (a) We have received a copy of the Offering Circular relating to
the Securities, and (b) any information we desire concerning the Securities,
the Common Stock, the Company or any other matter relevant to our decision to
purchase the Securities is or has been made available to us.

     4.   We have such knowledge and experience in financial and business
matters as to be capable of evaluating the merits and risks of an investment
in the Securities, and we are able to bear the economic risks of investment
in the Securities.

     5.   We are acquiring the Securities for our own account and not with a
view to any distribution of the Securities or the Conversion Shares, subject,
nevertheless, to the understanding that the disposition of our property shall
at all times be and remain within our control.

     6.   We agree that in the event that at some future time we wish to
dispose of any of the Securities or the Conversion Shares (such disposition
not being currently foreseen or contemplated), we will not transfer any of
the Securities or Conversion Shares unless:

     (A)  (1) the sale is to an Eligible Purchaser (as defined below) of at
     least U.S. $500,000 principal amount of Securities or market value of
     Conversion Shares, as the case may be, (2) a letter to substantially the
     same effect as this letter (excluding paragraph 3(a)) is executed
     promptly by the purchaser and (3) all offers or solicitations in
     connection with the sale, whether directly or through any agent acting
     on our behalf, are limited to Eligible Purchasers and are not made by
     means of any form of general advertising or solicitation; or

     (B) the Securities or Conversion Shares are transferred pursuant to Rule
     144 by us after we have held them for more than three years; or

     (C) such transfer is a transfer of Securities and is outside the United
     States to a non-United

<PAGE>

                                     C-3

     States person who represents in writing (i) that it is not purchasing
     the Securities for the account of a United States person and that it
     will not offer or sell any such Securities directly or indirectly in the
     United States or to any United States person, and (ii) if such person is
     a dealer in securities, that it will deliver to any person to whom it
     sells any such Securities a confirmation containing substantially the
     same statement, including this Clause; or

     (D) the Securities or Conversion Shares are transferred in any other
     transaction that does not require registration under the 1933 Act and we
     theretofore have furnished to the Company a satisfactory opinion of
     counsel to such effect.

     "United States" means the United States of America (including the States
and the District of Columbia), its territories, its possessions and other
areas subject to its jurisdiction, and "United States person" means any
citizen or resident of the United States, any corporation, partnership or
other entity created or organized in or under the laws of the United States
or any State thereof or any estate or trust the income of which is subject to
United States federal income taxation regardless of its source. "Eligible
Purchaser" means a corporation, partnership or other entity which we have
reasonable grounds to believe and do believe can make representations with
respect to itself to substantially the same effect as the representations set
forth herein.

                                       Very truly yours,

                                       [Name of U.S. Bank Branch]



                                       By
                                         --------------------------------------

<PAGE>

                                  EXHIBIT D

                  [Form of certificate to be given by SBCI]

                                 CERTIFICATE

                              CETUS CORPORATION

     5 1/4 PER CENT. CONVERTIBLE SUBORDINATED DEBENTURES DUE 2002

     This is to certify that we have received from a United States
Institutional Investor (as defined in the indenture pursuant to which the
above-captioned Securities of CETUS CORPORATION (the "Company") were issued)
a letter in the form submitted herewith.

     We believe that such United States Institutional Investor has such
knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of the investment, and that it is an
"accredited investor" within the meaning of Regulation D under the United
States Securities Act of 1933.

     We understand that this certificate is required in connection with the
United States law. We irrevocably authorize you to produce this certificate
or a copy hereof to any interested party in any administrative or legal
proceedings or official inquiry with respect to the matters covered by this
certificate.

Dated:               , 198

                                   SWISS BANK CORPORATION INTERNATIONAL LIMITED

                                   By
                                      ----------------------------------
                                             Authorized Officer
<PAGE>

                                 EXHIBIT E

          [Form of letter delivered by United States Institutional
          Investors, to be attached to the certificate given by SBCI]

CETUS CORPORATION
1400 Fifty-Third Street
Emeryville, California 94608

Swiss Bank Corporation International Limited
Three Keys House
130 Wood Street
London EC2V 6AQ

Re:  Purchase of U.S. $______ * principal amount of
     Cetus Corporation (the "Company") 5 1/4 per cent.
     Convertible Subordinated Debentures due 2002
     (the "Securities")
     -------------------------------------------------

                                                                         , 1987

Dear Sirs:

     In connection with our purchase of the Securities we confirm that:

     1.   We understand that the Securities are not being, and that the
shares of common stock (the "Common Stock") of the Company into which the
Securities are convertible (the "Conversion Shares") may not be, registered
under the United States Securities Act of 1933 (the "1933 Act") and that the
Securities are being sold to us in a transaction that is exempt from the
registration requirements of the 1933 Act.

     2.   (a) We have received a copy of the Offering Circular relating to
the Securities; and (b) any information we desire concerning the Securities,
the Common Stock, the Company thereof or any other matter relevant to our
decision to purchase the Securities is or has been made available to us.



-------------
*    Not less than U.S. $500,000 minimum principal amount.

<PAGE>

                                  E-2

    3.   We have such knowledge and experience in financial and business
matters as to be capable of evaluating the merits and risks of an investment
in the Securities, and we (and any account for which we are purchasing under
paragraph (iv) below) are able to bear the economic risks of investment in
the Securities.

     4.   We are acquiring the Securities for our own account and not as a
nominee or agent for any other person (except for accounts as to which we
exercise sole investment discretion) and not with a view to any distribution
of the Securities or the Conversion Shares subject, nevertheless, to the
understanding that the disposition of our property shall at all times be and
remain within our control.

     5.   We agree that in the event that at some future time we wish to
dispose of any of the Securities or the Conversion Shares (such disposition
not being currently foreseen or contemplated), we will not transfer any of
the Securities or Conversion Shares unless:

          (A) (1) the sale is to an Eligible Purchaser (as defined below) of at
     least U.S. $500,000 principal amount of Securities or market value of
     Conversion Shares, as the case may be, (2) a letter to substantially the
     same effect as this letter (excluding paragraph 2(a)) is executed
     promptly by the purchaser and (3) all offers or solicitations in
     connection with the sale, whether directly or through any agent acting
     on our behalf, are limited to Eligible Purchasers and are not made by
     means of any form of general solicitation or general advertising
     whatsoever;

          (B) the Securities or Conversion Shares are transferred pursuant to
     Rule 144 by us after we have held them for more than three years; or

          (C) the Securities or Conversion Shares are transferred in any
     other transaction that does not require registration under the 1933 Act
     and we theretofore have furnished to the Company a satisfactory opinion
     of counsel to such effect.

     6.   We understand that the Securities will be deposited with a common
depositary for the Euro-clear Clearance System and CEDEL S.A. in the form of
a temporary global security, that in order to receive definitive Securities
we (or any purchaser from us) will be required to make statements
substantially to the effect contained in this letter, that definitive
Securities will be issued to us (or any purchaser from us) only in registered
form, and


<PAGE>

                                     E-3

that the definitive Securities, and Conversion Shares, will bear a legend
to substantially the following effect (except that such Conversion Shares need
not bear the second legend):

          "This Security has not been registered under the United States
     Securities Act of 1933 and may not be offered or sold except in
     compliance with such Act. The transfer of this Security is subject to
     certain restrictions set forth in a letter to Swiss Bank Corporation
     International Limited and Cetus Corporation executed by or on behalf of
     the holder hereof.

          This Security cannot be exchanged for a Bearer Security."

The first paragraph of this legend may be removed upon determination by the
Company that the Security or Conversion Shares, as the case may be, have been
transferred pursuant to Rule 144 under the 1933 Act or if the Company has
received an opinion of counsel satisfactory to it to the effect that such
paragraph may be removed.

     "ELIGIBLE PURCHASER" means a corporation, partnership or other entity
which we have reasonable grounds to believe and do believe can make
representations with respect to itself to substantially the same effect as
the representations set forth herein.

                                      Very truly yours,

                                      ----------------------------
                                          (NAME OF PURCHASER)

                                      By
                                        --------------------------
                                           AUTHORIZED OFFICER